WorldWideScience

Sample records for host rock characterisation

  1. Programme for repository host rock characterisation in the ONKALO (ReRoC)

    International Nuclear Information System (INIS)

    Aalto, P.; Aaltonen, I.; Kemppainen, K.

    2009-04-01

    The excavation of the ONKALO is now entering the deep bedrock regime, where the ambient rock conditions are representative of those to be found in the vicinity of future deposition tunnels and deposition holes. It is proposed to study the properties of the rock under these conditions using specially-excavated rock rooms, investigation niches or stations and characterisation holes. This report provides an overview of these plans, which are designed to obtain the relevant site-specific knowledge. This report summarises the outstanding issues of the site modelling that are driving the deep rock investigations. It also lists the main long-term safety needs from the site characterisation and presents a short description of the data needs raised by the RSC (Rock Suitability Criteria) programme. The report presents the general characterisation programme of the ONKALO access tunnel. It includes geological mapping in the tunnel and the shafts and investigations in pilot, probe and characterisation hole. It also presents a programme for the pre-grouting hole studies in the shafts. The main aim of the report is to present the experimental studies that are to be carried out in the niches and studies that will be carried out below hydrogeological zone HZ20 at different locations in the tunnel, in order to obtain information on rock properties that are comparable to the rock at the disposal depth. This document provides a detailed discussion of the following experiments: (1) the sulphate reduction experiment at a depth of between 300-350 m to investigate the production, presence and effects of sulphide in the groundwater; (2) the hydrogeological interference experiment at tunnel chainage 3620 or 3748 for a detailed characterisation of connected fracture networks in the rock mass, representative of those in the near field of the deposition holes; (3) the rock matrix diffusion experiment(s) below chainage 4000 to determine the bedrock's essential retention properties for

  2. The RCF [Rock Characterisation Facility]: engineering issues. Proof of evidence

    International Nuclear Information System (INIS)

    Allison, J.A.

    1996-01-01

    Proof of Evidence by an expert witness is presented in support of the case by Friends of the Earth (FOE) against the proposed construction by UK Nirex Ltd of an underground Rock Characterisation Facility (RCF) at a site in the Sellafield area. The RCF is part of an investigation by Nirex into a suitable site for an underground repository for the disposal of radioactive waste. The objections were raised at a Planning Inquiry in 1995. The evidence focuses on the engineering issues in key areas of uncertainty which Nirex claim can only be resolved through the construction of an RCF. These are: groundwater flow and radionuclide transport; natural and induced changes in the geological barrier; the design and construction of the repository. Particular attention is drawn to the uncertainties regarding the groundwater pathway due to the dominant influence of fractures and variability in the host rock. Significant uncertainties about the host rock performance will remain after the construction of the RCF and associated tests are complete. (5 figures; 28 references). (UK)

  3. Heat production / host rock compatibility; Waermeentwicklung / Gesteinsvertraeglichkeit

    Energy Technology Data Exchange (ETDEWEB)

    Meleshyn, A.; Weyand, T.; Bracke, G.; Kull, H.; Wieczorek, K.

    2016-05-15

    For the final high-level radioactive waste repository potential host rock formations are either rock salt or clays (Kristallin). Heat generating waste (decay heat of the radioactive materials) can be absorbed by the host rock. The effect of temperature increase on the thermal conductivity, the thermal expansion and the mechanical properties of salt, Kristallin, clays and argilliferous geotechnical barriers are described. Further issues of the report are the mineralogical behavior, phase transformations, hydrochemistry, microbial processes, gas formation, thermochemical processes and gas ingress. Recommendations for further research are summarized.

  4. Host rock characteristics of uranium deposits of cataclastic-altered granite type

    International Nuclear Information System (INIS)

    Feng Mingyue

    1997-01-01

    The author expounds the host rock characteristics of uranium deposits of cataclastic-altered granite type, i.e., the high initial content of uranium, the high cataclasis of host rocks, the strong alteration of host rocks, the simple composition of host rocks favourable for the leaching of uranium, as well as the low content of harmful associated elements. These characteristics may be regarded as petrological criteria for recognition and prospecting for such type of uranium deposits

  5. Host rock characteristics of uranium deposits of cataclastic-altered granite type

    Energy Technology Data Exchange (ETDEWEB)

    Mingyue, Feng [Beijing Research Inst. of Uranium Geology (China)

    1997-03-01

    The author expounds the host rock characteristics of uranium deposits of cataclastic-altered granite type, i.e., the high initial content of uranium, the high cataclasis of host rocks, the strong alteration of host rocks, the simple composition of host rocks favourable for the leaching of uranium, as well as the low content of harmful associated elements. These characteristics may be regarded as petrological criteria for recognition and prospecting for such type of uranium deposits.

  6. A rock characterisation facility consultative document

    International Nuclear Information System (INIS)

    1992-10-01

    This U.K. Nirex Ltd., consultative document describes a proposed underground rock characterisation facility, east of Sellafield, for conducting geophysical surveys as a basis for refining long-term safety analysis of an underground repository for intermediate-level and low-level radioactive wastes. Planning application will be submitted in 1993. The construction of shafts and galleries is described and the site's geologic, topographical, climatic and archaeological features discussed. The effects to the local environment and on local populations and other socio-economic factors are discussed. (UK)

  7. Selection of the host rock for high level radioactive waste repository in China

    International Nuclear Information System (INIS)

    Jin Yuanxin; Wang Wenguang; Chen Zhangru

    2001-01-01

    The authors has briefly introduced the experiences of the host rock selection and the host rock types in other countries for high level radioactive waste repository. The potential host rocks in China are investigated. They include granite, tuff, clay, basalt, salt, and loess. The report has expounded the distributions, scale, thickness, mineral and chemical composition, construction, petrogenesis and the ages of the rock. The possibility of these rocks as the host rock has been studied. The six pieces of distribution map of potential rocks have been made up. Through the synthetical study, it is considered that granite as the host rock of high level radioactive waste repository is possible

  8. Combined rock-physical modelling and seismic inversion techniques for characterisation of stacked sandstone reservoir

    NARCIS (Netherlands)

    Justiniano, A.; Jaya, Y.; Diephuis, G.; Veenhof, R.; Pringle, T.

    2015-01-01

    The objective of the study is to characterise the Triassic massive stacked sandstone deposits of the Main Buntsandstein Subgroup at Block Q16 located in the West Netherlands Basin. The characterisation was carried out through combining rock-physics modelling and seismic inversion techniques. The

  9. Nagra technical report 14-02, Geological basics - Dossier VI - Barrier properties of proposed host rock sediments and neighbouring rock

    International Nuclear Information System (INIS)

    Gautschi, A.; Deplazes, G.; Traber, D.; Marschall, P.; Mazurek, M.; Gimmi, T.; Maeder, U.

    2014-01-01

    This dossier is the sixth of a series of eight reports concerning the safety and technical aspects of locations for the disposal of radioactive wastes in Switzerland. It discusses the barrier properties of the proposed host rock sediments and neighbouring rock layers. The mineralogical composition of the host rocks are discussed as are their pore densities and hydrological properties. Diffusion aspects are discussed. The aquifer systems in the proposed depository areas and their classification are looked at. The barrier properties of the host rocks and those of neighbouring sediments are discussed. Finally, modelling concepts and parameters for the transport of radionuclides in the rocks are discussed

  10. Characterisation of gas transport properties of the Opalinus clay, a potential host rock formation for radioactive waste disposal

    International Nuclear Information System (INIS)

    Marschall, P.; Horseman, S.; Gimmi, T.

    2005-01-01

    The Opalinus Clay in Northern Switzerland has been identified as a potential host rock formation for the disposal of radioactive waste. Comprehensive understanding of gas transport processes through this low-permeability formation forms a key issue in the assessment of repository performance. Field investigations and laboratory experiments suggest an intrinsic permeability of the Opalinus Clay in the order of 10 -20 to 10 -21 m 2 and a moderate anisotropy ratio ≤ 10. Porosity depends on clay content and burial depth; values of ∼ 0.12 are reported for the region of interest. Porosimetry indicates that about 10-30% of voids can be classed as macro-pores, corresponding to an equivalent pore radius > 25 nm. The determined entry pressures are in the range of 0.4-10 MPa and exhibit a marked dependence on intrinsic permeability. Both in situ gas tests and gas permeameter tests on drill-cores demonstrate that gas transport through the rock is accompanied by pore water displacement, suggesting that classical flow concepts of immiscible displacement in porous media can be applied when the gas entry pressure (i.e. capillary threshold pressure) is less than the minimum principal stress acting within the rock. Essentially, the pore space accessible to gas flow is restricted to the network of connected macro-pores, which implies a very low degree of desaturation of the rock during the gas imbibition process. At elevated gas pressures (i.e. when gas pressure approaches the level of total stress that acts on the rock body), evidence was seen for dilatancy controlled gas transport mechanisms. Further field experiments were aimed at creating extended tensile fractures with high fracture transmissivity (hydro- or gas-fractures). The test results lead to the conclusion that gas fracturing can be largely ruled out as a risk for post-closure repository performance. (authors)

  11. NIREX transport activities since rejection of the rock characterisation facility planning application

    International Nuclear Information System (INIS)

    Barlow, S.; Carr, N.; Sievwright, R.W.T.

    2000-01-01

    The application by Nirex to build an underground Rock Characterisation Facility, was rejected by the Secretary of State on 17 March 1997. This decision has caused Nirex to reconsider its forward programme for the development of an underground disposal facility for intermediate level waste. This paper describes the transport related activities being undertaken by Nirex since that date. (author)

  12. Gabbro as a host rock for a nuclear waste repository

    International Nuclear Information System (INIS)

    Ahlbom, K.; Leijon, B.; Smellie, J.; Liedholm, M.

    1992-09-01

    As an alternative to granitic rocks, gabbro and other basic rock types have been investigated with respect to their suitability to host a nuclear waste repository. The present report summarizes and examines existing geoscientific knowledge of relevance in assessing the potential merits of gabbro as a repository host rock. Implications in terms of site selection, repository construction and post-closure repository performance are also discussed. The objective of the study is to provide a basis for decisions as regards future consideration of the gabbro alternative. It is found that there are rather few gabbro bodies in Sweden, that are potentially of sufficient size to host a repository. Thus, gabbro offers little latitude as regards site selection. In comparison to siting a repository in granitic rocks, this is a major disadvantage, and it may in fact remove gabbro from further consideration. The potential advantages of gabbro refer to repository performance, and include low hydraulic conductivity and a chemical environment promoting efficient radionuclide retardation. However, results from field investigations show that groundwater flow in gabbro bodies is largely controlled by intersecting heterogeneities, in particular granitic dykes, that are significantly more conductive to water than the gabbro. In the far-field scale significant to repository performance, this may reduce or eliminate the potential effects of favourable hydraulic and chemical characteristics of the gabbro itself. In conclusion, there are apparent difficulties associated with siting a repository in gabbro, due to lack of sufficiently large gabbro bodies. On the basis of the present state of knowledge, no decisive differences can be demonstrated when comparing gabbro with granitic rocks, neither with respects to repository construction, nor as regards repository performance. (au)

  13. Investigations on THM effects in buffer, EDZ and argillaceous host rock. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Jobmann, M.; Breustedt, M.; Li, S.; Polster, M.; Schirmer, S.

    2013-11-15

    In the Federal Republic of Germany the final disposal of heat-generating radioactive waste in clay formations is investigated as an alternative to the reference concept in a salt formation. The main concern when switching to a clay host rock is the high amount of heat released from the canisters into the clay rock over a long period of time. It is still an open question to what extent the host rock formation is affected by the released heat and if this is a threat to safety. The released heat from the canisters is a load on the whole barrier system, which consists of the geotechnical barriers (buffer and plugs) and the geological barrier. The temperature has a direct impact on the buffer, the excavative damaged zone (EDZ) and the surrounding host rock. The buffer has specific thermo-physical properties that significantly influence the temperature evolution in the near field so that a temperature load on the buffer is of special concern. Thus, with regard to thermal criteria, the buffer plays a significant role for the design of the emplacement fields. An open question is whether the use of admixtures could enhance the thermo-physical properties so that the heat release into the host rock would be more efficient. Due to the permanent heat release and the continuous emplacement of additional canisters, the in-situ stress state in the vicinity of the emplacement boreholes continuously varies during the operational period and beyond. It is an open question how the EDZ of emplacement boreholes evolves in the long term with regard to its fissure system and mainly its permeability. A closure of the EDZ and a corresponding decrease in its permeability are necessary to enhance the tightness of the barrier system, especially to avoid a preferential pathway through the EDZ around the openings. The host rock has specific properties that are necessary to ensure a safe enclosure of the waste. A change in the host rock temperature may change these properties irreversibly. This is

  14. Experience gained from the site characterisation strategy used at the Aespoe hard rock laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Baeckblom, G. [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    1998-09-01

    The Aespoe Hard Rock Laboratory is a `dress-rehearsal` facility to test, develop and demonstrate technology and models prior to applications at the actual deep repository site in Sweden. Site characterisation methodology has for more than a decade been a main issue at the Aespoe Hard Rock Laboratory (HRL). At the start of site investigations in 1987 the following strategy was adopted: Comprehensive surface and surface-based investigations; Multi-disciplinary data collection in batches; Staged integrated evaluations on selected key issues closely tied to existing knowledge of the geology of the site; Iterative modelling on several geometrical scales based on existing (scarce) data; `Predictive approach` to model updating. During the construction phase of the Aespoe HRL (1990 - 1995), a multitude of data was collected to test and to increase the details of the models made prior to construction. Several things have been learned regarding the appropriateness of the adopted approach to site characterisation. These findings concern e.g. data collection methods from surface and underground, construction/test-integration, choice of useful and feasible model concepts, data flow and document management. The acquired understanding, knowledge, skill and know-how are very valuable for planning useful and feasible site characterisation for the deep repository in Sweden

  15. Experience gained from the site characterisation strategy used at the Aespoe hard rock laboratory

    International Nuclear Information System (INIS)

    Baeckblom, G.

    1998-01-01

    The Aespoe Hard Rock Laboratory is a 'dress-rehearsal' facility to test, develop and demonstrate technology and models prior to applications at the actual deep repository site in Sweden. Site characterisation methodology has for more than a decade been a main issue at the Aespoe Hard Rock Laboratory (HRL). At the start of site investigations in 1987 the following strategy was adopted: Comprehensive surface and surface-based investigations; Multi-disciplinary data collection in batches; Staged integrated evaluations on selected key issues closely tied to existing knowledge of the geology of the site; Iterative modelling on several geometrical scales based on existing (scarce) data; 'Predictive approach' to model updating. During the construction phase of the Aespoe HRL (1990 - 1995), a multitude of data was collected to test and to increase the details of the models made prior to construction. Several things have been learned regarding the appropriateness of the adopted approach to site characterisation. These findings concern e.g. data collection methods from surface and underground, construction/test-integration, choice of useful and feasible model concepts, data flow and document management. The acquired understanding, knowledge, skill and know-how are very valuable for planning useful and feasible site characterisation for the deep repository in Sweden

  16. Host Rock Classification (HRC) system for nuclear waste disposal in crystalline bedrock

    International Nuclear Information System (INIS)

    Hagros, A.

    2006-01-01

    A new rock mass classification scheme, the Host Rock Classification system (HRC-system) has been developed for evaluating the suitability of volumes of rock mass for the disposal of high-level nuclear waste in Precambrian crystalline bedrock. To support the development of the system, the requirements of host rock to be used for disposal have been studied in detail and the significance of the various rock mass properties have been examined. The HRC-system considers both the long-term safety of the repository and the constructability in the rock mass. The system is specific to the KBS-3V disposal concept and can be used only at sites that have been evaluated to be suitable at the site scale. By using the HRC-system, it is possible to identify potentially suitable volumes within the site at several different scales (repository, tunnel and canister scales). The selection of the classification parameters to be included in the HRC-system is based on an extensive study on the rock mass properties and their various influences on the long-term safety, the constructability and the layout and location of the repository. The parameters proposed for the classification at the repository scale include fracture zones, strength/stress ratio, hydraulic conductivity and the Groundwater Chemistry Index. The parameters proposed for the classification at the tunnel scale include hydraulic conductivity, Q' and fracture zones and the parameters proposed for the classification at the canister scale include hydraulic conductivity, Q', fracture zones, fracture width (aperture + filling) and fracture trace length. The parameter values will be used to determine the suitability classes for the volumes of rock to be classified. The HRC-system includes four suitability classes at the repository and tunnel scales and three suitability classes at the canister scale and the classification process is linked to several important decisions regarding the location and acceptability of many components of

  17. Support to other nuclear waste disposal programmes considering clay as a potential host rock

    International Nuclear Information System (INIS)

    Volckaert, G.

    2009-01-01

    SCK-CEN started to study the Boom Clay as potential host rock for nuclear waste disposal in 1974. Since then, SCK-CEN has been involved in other international projects studying clay as potential host rock in order to get a broader support for disposal in clay and to acquire broader insight in clay behaviour. Besides Belgium, France and Switzerland are currently investigating clay formations as potential host rock for the disposal of radioactive waste. In the Netherlands, clay formations have always been considered as an alternative to disposal in salt. The general interest in clays is increasing: in Germany and The United Kingdom, it was decided a few years ago that besides respectively salt and crystalline rock also clays need to be evaluated. In Eastern and Central Europe, the Slovak republic and Lithuania consider both clay and granite as possible host rocks for spent fuel while in Russia recently a project was started to study the possible disposal of low and medium level waste in a clay formation in the Leningrad area. Within the EC research and development framework programs and the OECD/NEA Clay Club, collaborations were developed between countries studying clay and with a strong involvement of SCK-CEN. The collaboration with the Eastern and Central European countries is supported through the support programme of the Belgian Ministry of Economic affairs. The objectives of these co-operations are to deliver expert services to other nuclear waste disposal programs considering clay as host rock; to to acquire broader international recognition of our expertise and support for the development of nuclear waste disposal in clay; to get a broader insight in the properties and behaviour of clays

  18. Characterising the reactivity of metallic iron in Fe 0 /As-rock/H 2 O ...

    African Journals Online (AJOL)

    The intrinsic reactivity of 4 metallic iron materials (Fe0) was investigated in batch and column experiments. The Fe0 reactivity was characterised by the extent of aqueous fixation of in-situ leached arsenic (As). Air-homogenised batch experiments were conducted for 1 month with 10.0 g/. of an As-bearing rock (ore material) ...

  19. Organic tissues, graphite, and hydrocarbons in host rocks of the Rum Jungle Uranium Field, northern Australia

    Science.gov (United States)

    Foster, C.B.; Robbins, E.I.; Bone, Y.

    1990-01-01

    The Rum Jungle Uranium field consists of at least six early Proterozoic deposits that have been mined either for uranium and/or the associated base and precious metals. Organic matter in the host rocks of the Whites Formation and Coomalie Dolomite is now predominantly graphite, consistent with the metamorphic history of these rocks. For nine samples, the mean total organic carbon content is high (3.9 wt%) and ranged from 0.33 to 10.44 wt%. Palynological extracts from the host rocks include black, filamentous, stellate (Eoastrion-like), and spherical morphotypes, which are typical of early Proterozoic microbiota. The colour, abundance, and shapes of these morphotypes reflect the thermal history, organic richness, and probable lacustrine biofacies of the host rocks. Routine analysis of rock thin sections and of palynological residues shows that mineral grains in some of the host rocks are coated with graphitized organic matter. The grain coating is presumed to result from ultimate thermal degradation of a petroleum phase that existed prior to metamorphism. Hydrocarbons are, however, still present in fluid inclusions within carbonates of the Coomalie Dolomite and lower Whites Formation. The fluid inclusions fluoresce dull orange in blue-light excitation and their hydrocarbon content is confirmed by gas chromatography of whole-rock extracts. Preliminary analysis of the oil suggests that it is migrated, and because it has escaped graphitization through metamorphism it is probably not of early Proterozoic age. The presence of live oil is consistent with fluid inclusion data that suggest subsequent, low-temperature brine migration through the rocks. The present observations support earlier suggestions that organic matter in the host formations trapped uranium to form protore. Subsequent fluid migrations probably brought additional uranium and other metals to these formations, and the organic matter provided a reducing environment for entrapment. ?? 1990.

  20. A preliminary study on the suitability of host rocks for deep geological disposal of high level radioactive waste in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chun Soo; Bae, Dae Seok; Kim, Kyung Su; Park, Byung Yun; Koh, Young Kown

    2000-02-01

    It is expected that the key issues are listed as the disposal concept, reference disposal system and other relevant technical development for the deep geological disposal of HLW in each country. First above all, however, the preferred host rocks should be suggested prior execution of these activities. And, it is desirable to be reviewed and proposed some host rocks representative its country. For the reviewing of host rocks in Korean peninsula, several issues were considered such as the long-term geological stability, fracture system, surface and groundwater system and geochemical characteristics in peninsula. The three rock types such as plutonic rocks, crystalline gneisses and massive volcanic rocks were suggested as the preferred host rocks for the R and D of HLW disposal based on the upper stated information. In the following stages, it is suggested that these preferred host rocks would be made an object of all relevant R and D activities for HLW disposal. And, many references for these geologic medium should be characterized and constructed various technical development for the Korean reference disposal system.

  1. A preliminary study on the suitability of host rocks for deep geological disposal of high level radioactive waste in Korea

    International Nuclear Information System (INIS)

    Kim, Chun Soo; Bae, Dae Seok; Kim, Kyung Su; Park, Byung Yun; Koh, Young Kown

    2000-02-01

    It is expected that the key issues are listed as the disposal concept, reference disposal system and other relevant technical development for the deep geological disposal of HLW in each country. First above all, however, the preferred host rocks should be suggested prior execution of these activities. And, it is desirable to be reviewed and proposed some host rocks representative its country. For the reviewing of host rocks in Korean peninsula, several issues were considered such as the long-term geological stability, fracture system, surface and groundwater system and geochemical characteristics in peninsula. The three rock types such as plutonic rocks, crystalline gneisses and massive volcanic rocks were suggested as the preferred host rocks for the R and D of HLW disposal based on the upper stated information. In the following stages, it is suggested that these preferred host rocks would be made an object of all relevant R and D activities for HLW disposal. And, many references for these geologic medium should be characterized and constructed various technical development for the Korean reference disposal system

  2. Nectonema zealandica n. sp. (Nematomorpha: Nectonematoidea) parasitising the purple rock crab Hemigrapsus edwardsi (Brachyura: Decapoda) in New Zealand, with notes on the prevalence of infection and host defence reactions.

    Science.gov (United States)

    Poinar, G; Brockerhoff, A M

    2001-10-01

    A new species of marine hairworm, Nectonema zealandica (Nematomorpha: Nectonematoidea), is described from the purple rock crab Hemigrapsus edwardsi Hilgendorf from the South Island, New Zealand. This is the first record of Nectonema in the South Pacific Ocean and the southernmost locality for the genus. The description is based on juveniles and pre-adults taken from crabs. The new species is characterised by its stomal structure, presence of four cephalic papillae, mesenchyme arranged in eight lobes in pre-adults, insertion of muscle layer increasing body diameter at the septum and translucent anterior chamber. Data on the prevalence of infection over a three-year period, rates of parasitism in relation to host sex and size, and host defence reactions are presented. A list of all reported hosts of nectonematids is included.

  3. Application of Ga-Al discrimination plots in identification of high strength granitic host rocks for deep geological repository of high level radioactive waste

    International Nuclear Information System (INIS)

    Bajpai, R.K.; Narayan, P.K.; Trivedi, R.K.; Purohit, M.K.

    2010-01-01

    The permanent disposal of vitrified high level wastes and in some cases even spent fuel, is being planned in specifically designed and built deep geological repository located in the depth range of 500-600m in appropriate host rock at carefully selected sites. Such facilities are expected to provide very long term isolation and confinement to the disposed waste by means of long term mechanical stability of such structures that results from very high strength and homogeneity of the chosen rock, geochemical compatible environment around the disposed waste and general lack of groundwater. In Indian geological repository development programme, granites have been selected as target host rock and large scale characterization studies have been undertaken to develop database of mineralogy, petrology, geochemistry and rock mechanical characteristics. The paper proposes a new approach for demarcation of high strength homogeneous granite rocks from within an area of about 100 square kilometres wherein a cocktail of granites of different origins with varying rock mass characteristics co exists. The study area is characterised by the presence of A, S and I type granites toughly intermixed. The S type granites are derived from sedimentary parent material and therefore carry relics of parent fabric and at times undigested material with resultant reduction in their strength and increased inhomogeneity. On the other hand I type varieties are derived from igneous parents and are more homogeneous with sufficient strength. The A type granites are emplaced as molten mass in a complete non-tectonic setting with resultant homogeneous compositions, absence of tectonic fabric and very high strength. Besides they are silica rich with less vulnerability to alterations with time. Thus A type granites are most suited for construction of Deep Geological Repository. For developing a geochemical approach for establishing relation between chemical compositions and rock strength parameters, a

  4. Effect of image scaling and segmentation in digital rock characterisation

    Science.gov (United States)

    Jones, B. D.; Feng, Y. T.

    2016-04-01

    Digital material characterisation from microstructural geometry is an emerging field in computer simulation. For permeability characterisation, a variety of studies exist where the lattice Boltzmann method (LBM) has been used in conjunction with computed tomography (CT) imaging to simulate fluid flow through microscopic rock pores. While these previous works show that the technique is applicable, the use of binary image segmentation and the bounceback boundary condition results in a loss of grain surface definition when the modelled geometry is compared to the original CT image. We apply the immersed moving boundary (IMB) condition of Noble and Torczynski as a partial bounceback boundary condition which may be used to better represent the geometric definition provided by a CT image. The IMB condition is validated against published work on idealised porous geometries in both 2D and 3D. Following this, greyscale image segmentation is applied to a CT image of Diemelstadt sandstone. By varying the mapping of CT voxel densities to lattice sites, it is shown that binary image segmentation may underestimate the true permeability of the sample. A CUDA-C-based code, LBM-C, was developed specifically for this work and leverages GPU hardware in order to carry out computations.

  5. Use of structural geology in exploration for and mining of sedimentary rock-hosted Au deposits

    Science.gov (United States)

    Peters, Stephen G.

    2001-01-01

    Structural geology is an important component in regional-, district- and orebody-scale exploration and development of sedimentary rock-hosted Au deposits.Identification of timing of important structural events in an ore district allows analysis and classification of fluid conduits and construction of genetic models for ore formation.The most practical uses of structural geology deal with measurement and definition of various elements that comprise orebodies, which can then be directly applied to ore-reserve estimation,ground control,grade control, safety issues,and mine planning.District- and regional-scale structural studies are directly applicable to long-term strategic planning,economic analysis,and land ownership. Orebodies in sedimentary rock-hosted Au deposits are discrete, hypogene, epigenetic masses usually hosted in a fault zone,breccia mass, or lithologic bed or unit. These attributes allow structural geology to be directly applied to the mining and exploration of sedimentary rock-hosted Au deposits. Internal constituents in orebodies reflect unique episodes relating to ore formation.The main internal constituents in orebodies are ore minerals, gangue, and alteration minerals that usually are mixed with one another in complex patterns, the relations among which may be used to interpret the processes of orebody formation and control.Controls of orebody location and shape usually are due to structural dilatant zones caused by changes in attitude, splays, lithologic contacts,and intersections of the host conduit or unit.In addition,conceptual parameters such as district fabric,predictable distances, and stacking also are used to understand the geometry of orebodies.Controls in ore districts and location and geometry of orebodies in ore districts can be predicted to various degrees by using a number of qualitative concepts such as internal and external orebody plunges,district plunge, district stacking, conduit classification, geochemical, geobarometric and

  6. Analysis of hydraulic gradients across the host rock at the proposed Texas Panhandle nuclear-waste repository site

    International Nuclear Information System (INIS)

    Bair, E.S.

    1987-01-01

    Analysis of the direction of ground-water flow across the host rock at the proposed high-level nuclear-waste repository site in Deaf Smith County, Texas, is complicated by vertical and lateral changes in the density of formation fluids in the various hydrogeologic units that overlie and underlie the proposed host rock. Because the concept of hydraulic head is not valid when evaluating vertical hydraulic gradients in a variably-density flow system, other methods were used to determine the direction and magnitude of vertical hydraulic gradients at the proposed site where the specific gravity of formation fluids varies between 1.00 and 1.28. The direction of ground-water flow across the proposed host rock, an 80-foot-thick salt bed in the Lower San Andres Formation, was determined by calculating vertical hydraulic gradients based on formation pressure and fluid density data, and by analysis of pressure-depth diagrams. Based on data from the vicinity of the proposed site, both methods indicate the potential for downflow across the host rock. Downflow or predominantly horizontal flow is considered a favorable prewaste emplacement condition because it prolongs the travel time to the biosphere of any naturally or accidentally released radionuclides

  7. Clay club catalogue of characteristics of argillaceous rocks

    International Nuclear Information System (INIS)

    2005-01-01

    The OECD/NEA Working Group on the Characterisation, the Understanding and the Performance of Argillaceous Rocks as Repository Host Formations, namely the Clay Club, examines the various argillaceous rocks that are being considered for the deep geological disposal of radioactive waste, i.e. from plastic, soft, poorly indurated clays to brittle, hard mud-stones or shales. The Clay Club considered it necessary and timely to provide a catalogue to gather in a structured way the key geo-scientific characteristics of the various argillaceous formations that are - or were - studied in NEA member countries with regard to radioactive waste disposal. The present catalogue represents the outcomes of this Clay Club initiative. (author)

  8. Microorganisms in potential host rocks for geological disposal of nuclear waste and their interactions with radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Cherkouk, A.; Liebe, M.; Luetke, L.; Moll, H.; Stumpf, T. [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Inst. of Resource Ecology

    2015-07-01

    The long-term safety of nuclear waste in a deep geological repository is an important issue in our society. Microorganisms indigenous to potential host rocks are able to influence the oxidation state, speciation and therefore the mobility of radionuclides as well as gas generation or canister corrosion. Therefore, for the safety assessment of such a repository it is necessary to know which microorganisms are present in the potential host rocks (e.g. clay, salt) and if these microorganisms can influence the performance of a repository. Microbial diversity in potential host rocks for geological disposal of nuclear waste was analyzed by culture-independent molecular biological methods (e.g. 16S rRNA gene retrieval) as well as enrichment and isolation of indigenous microbes. Among other isolates, a Paenibacillus strain, as a representative of Firmicutes, was recovered in R2A media under anaerobic conditions from Opalinus clay from the Mont Terri in Switzerland. Accumulation experiments and potentiometric titrations showed a strong interaction of Paenibacillus sp. cells with U(VI) within a broad pH range (3-7). Additionally, the interactions of the halophilic archaeal strain Halobacterium noricense DSM 15987, a salt rock representative reference strain, with U(VI) at high ionic strength was investigated. After 48 h the cells were still alive at uranium concentrations up to 60 μM, which demonstrates that Halobacterium noricense can tolerate uranium concentrations up to this level. The formed uranium sorption species were examined with time-resolved laser-induced fluorescence spectroscopy (TRLFS). The results about the microbial communities present in potential host rocks for nuclear waste repositories and their interactions with radionuclides contribute to the safety assessment of a prospective nuclear waste repository.

  9. Microorganisms in potential host rocks for geological disposal of nuclear waste and their interactions with radionuclides

    International Nuclear Information System (INIS)

    Cherkouk, A.; Liebe, M.; Luetke, L.; Moll, H.; Stumpf, T.

    2015-01-01

    The long-term safety of nuclear waste in a deep geological repository is an important issue in our society. Microorganisms indigenous to potential host rocks are able to influence the oxidation state, speciation and therefore the mobility of radionuclides as well as gas generation or canister corrosion. Therefore, for the safety assessment of such a repository it is necessary to know which microorganisms are present in the potential host rocks (e.g. clay, salt) and if these microorganisms can influence the performance of a repository. Microbial diversity in potential host rocks for geological disposal of nuclear waste was analyzed by culture-independent molecular biological methods (e.g. 16S rRNA gene retrieval) as well as enrichment and isolation of indigenous microbes. Among other isolates, a Paenibacillus strain, as a representative of Firmicutes, was recovered in R2A media under anaerobic conditions from Opalinus clay from the Mont Terri in Switzerland. Accumulation experiments and potentiometric titrations showed a strong interaction of Paenibacillus sp. cells with U(VI) within a broad pH range (3-7). Additionally, the interactions of the halophilic archaeal strain Halobacterium noricense DSM 15987, a salt rock representative reference strain, with U(VI) at high ionic strength was investigated. After 48 h the cells were still alive at uranium concentrations up to 60 μM, which demonstrates that Halobacterium noricense can tolerate uranium concentrations up to this level. The formed uranium sorption species were examined with time-resolved laser-induced fluorescence spectroscopy (TRLFS). The results about the microbial communities present in potential host rocks for nuclear waste repositories and their interactions with radionuclides contribute to the safety assessment of a prospective nuclear waste repository.

  10. Lithophysal Rock Mass Mechanical Properties of the Repository Host Horizon

    International Nuclear Information System (INIS)

    D. Rigby

    2004-01-01

    The purpose of this calculation is to develop estimates of key mechanical properties for the lithophysal rock masses of the Topopah Spring Tuff (Tpt) within the repository host horizon, including their uncertainties and spatial variability. The mechanical properties to be characterized include an elastic parameter, Young's modulus, and a strength parameter, uniaxial compressive strength. Since lithophysal porosity is used as a surrogate property to develop the distributions of the mechanical properties, an estimate of the distribution of lithophysal porosity is also developed. The resulting characterizations of rock parameters are important for supporting the subsurface design, developing the preclosure safety analysis, and assessing the postclosure performance of the repository (e.g., drift degradation and modeling of rockfall impacts on engineered barrier system components)

  11. Petrogenesis and geochemical characterisation of ultramafic cumulate rocks from Hawes Head, Fiordland, New Zealand

    International Nuclear Information System (INIS)

    Daczko, N.R.; Emami, S.; Allibone, A.H.; Turnbull, I.M.

    2012-01-01

    Early Cretaceous parts of the western Median Batholith (Western Fiordland Orthogneiss) represent the exposed root of a magmatic arc of dioritic to monzodioritic composition (SiO 2 = 51-55 wt%; Na 2 O/K 2 O = 3.7-8.8 in this study). We characterise for the first time the field relationships, petrography, mineralogy and geochemistry of ultramafic and mafic cumulates at Hawes Head, the largest exposure of ultramafic rocks in western Fiordland. We distinguish three related rock types at Hawes Head: hornblende peridotite (MgO = 21-35 wt%); hornblendite (MgO = 15-16 wt%); and pyroxenite (MgO = 21 wt%). Petrogenetic relationships between the ultramafic rocks and the surrounding Misty Pluton of the Western Fiordland Orthogneiss are demonstrated by: (i) mutually cross-cutting relationships; (ii) similar mafic phases (e.g. pyroxene and amphibole) with elevated Mg-numbers (e.g. olivine Mg/(Mg+Fe) = 0.77-0.82); (iii) fractionation trends in mineral geochemistry; and (iv) shared depleted heavy rare earth element patterns. In addition, the application of solid/liquid partition coefficients indicates that olivine in the ultramafic rocks at Hawes Head crystallised from a magma with Mg/(Mg+Fe) = 0.54-0.57. The olivine grains therefore represent a plausible early crystallising phase of the adjacent Western Fiordland Orthogneiss (Mg/(Mg+Fe) = 0.51-0.55). (author). 42 refs., 5 figs., 1 tab.

  12. Repository for high level radioactive wastes in Brazil: the importance of geochemical (Micro thermometric) studies and fluid migration in potential host rocks

    International Nuclear Information System (INIS)

    Rios, Francisco Javier; Fuzikawa, Kazuo; Alves, James Vieira; Neves, Jose Marques Correia

    2003-01-01

    A detailed fluid inclusion study of host rocks, is of fundamental importance in the selection of geologically suitable areas for high level nuclear waste repository constructions (HLRW). The LIFM-CDTN is enabled to develop studies that confirm: the presence or not, of corrosive fluid in minerals from host rocks of the repository and the possible presence of micro fractures (and fluid leakage) when these rocks are submitted to high temperatures. These fluid geochemistry studies, with permeability determinations by means of pressurized air injection must be carried out in rocks hosting nuclear waste. Micro fracture determination is of vital importance since many naturally corrosive solutions, present in the mineral rocks, could flow out through these plans affecting the walls of the repository. (author)

  13. Clay club initiative: self-healing of fractures in clay-rich host rocks

    International Nuclear Information System (INIS)

    Horseman, S.T.; Cuss, R.J.; Reeves, H.J.

    2004-01-01

    The capacity of fractures in argillaceous rocks to self-heal (or become, with the passage of time, less conductive to groundwater) is often cited as a primary factor favouring the choice of such materials as host rocks for deep disposal. The underlying processes which contribute to self-healing can be broadly subdivided into: (a) mechanical and hydro-mechanical processes linked to the change in the stress field, movement of pore water, swelling, softening, plastic deformation and creep, and (b) geochemical processes linked to chemical alterations, transport in aqueous solution and the precipitation of minerals. Since chemical alteration can cause profound changes to the mechanical properties of argillaceous rocks, it is often difficult to draw a firm line between these two subdivisions. Based on the deliberations of the recent Cluster Conference in Luxembourg, there would appear to be some support for the use of the term 'self-sealing' for processes affecting fracture conductivity in argillaceous rock that are largely mechanical or hydro-mechanical in their origin. There are four main areas in which the self-healing capacity of the host rock becomes relevant to repository design and performance assessment: - potential for radionuclide transport within the excavation damage zone (EDZ); - design and performance of repository sealing systems; - potential impact of gas migration; - long-term performance considering erosional unloading, seismicity and fault reactivation. The presence of an EDZ is acknowledged to be a particularly important issue in performance assessment. Interconnection of fractures in the EDZ could lead to the development of a preferential flow path extending along the emplacement holes, access tunnels and shafts of a repository towards overlying aquifers and the biosphere. In the preliminary French Safety Analyses, for example, the treatment of scenarios relating to early seal failure have highlighted the hydraulic role of the damaged zone as a

  14. ONKALO. Underground characterisation and research programme (UCRP)

    International Nuclear Information System (INIS)

    2003-09-01

    The purpose of the ONKALO Underground Characterisation and Research Programme (UCRP) is to explore Olkiluoto rock conditions and thereby enhance the current geoscientific understanding of the site, to allow the submission of an application for a construction licence for the deep repository. The characterisation programme has the following geoscientific goals: to develop and demonstrate techniques for detailed characterising volumes of rock from the underground, to update the current descriptive model of Olkiluoto bedrock and to increase confidence in this model such that it will serve the needs of construction and the Preliminary Safety Assessment Report (PSAR) in the construction licence application, and to identify volumes of rock that could be suitable for housing parts of the repository. The development of ONKALO will be based on coordinated investigation, design and construction activities. Mapping data from the tunnel front and data obtained from short probe holes will constitute most of the data needed to control the construction of ONKALO. Pilot holes will be drilled along the tunnel profile as the excavation proceeds and investigations will be carried out for geological, rock mechanics, hydrogeological and hydrogeochemical characterisation. Investigations cover more detailed mapping and sampling in parts of the tunnel, mapping and sampling of potential groundwater inflows to the tunnel and investigations from characterisation bore holes drilled from ONKALO. In addition, monitoring is planned in surface-drilled boreholes, in boreholes drilled from ONKALO, and in ONKALO itself. Monitoring will reveal changes in bedrock conditions and thus provide important information for site characterisation. The information collected by characterisation and monitoring will all be assessed in an integrated modelling effort. The aim of this modelling is both to successively enhance the description and understanding of the rock volume around ONKALO and to assess potential

  15. Finite-element modeling of magma chamber-host rock interactions prior to caldera collapse

    Science.gov (United States)

    Kabele, Petr; Žák, Jiří; Somr, Michael

    2017-06-01

    Gravity-driven failure of shallow magma chamber roofs and formation of collapse calderas are commonly accompanied by ejection of large volumes of pyroclastic material to the Earth's atmosphere and thus represent severe volcanic hazards. In this respect, numerical analysis has proven as a key tool in understanding the mechanical conditions of caldera collapse. The main objective of this paper is to find a suitable approach to finite-element simulation of roof fracturing and caldera collapse during inflation and subsequent deflation of shallow magma chambers. Such a model should capture the dominant mechanical phenomena, for example, interaction of the host rock with magma and progressive deformation of the chamber roof. To this end, a comparative study, which involves various representations of magma (inviscid fluid, nearly incompressible elastic, or plastic solid) and constitutive models of the host rock (fracture and plasticity), was carried out. In particular, the quasi-brittle fracture model of host rock reproduced well the formation of tension-induced radial and circumferential fractures during magma injection into the chamber (inflation stage), especially at shallow crustal levels. Conversely, the Mohr-Coulomb shear criterion has shown to be more appropriate for greater depths. Subsequent magma withdrawal from the chamber (deflation stage) results in further damage or even collapse of the chamber roof. While most of the previous studies of caldera collapse rely on the elastic stress analysis, the proposed approach advances modeling of the process by incorporating non-linear failure phenomena and nearly incompressible behaviour of magma. This leads to a perhaps more realistic representation of the fracture processes preceding roof collapse and caldera formation.

  16. Clay shale as host rock. A geomechanical contribution about Opalinus clay

    International Nuclear Information System (INIS)

    Lempp, Christof; Menezes, Flora; Sachwitz, Simon

    2016-01-01

    The Opalinuston is a prominent rock representing the type of organic clay shales or clay stones within the sequence of Triassic and Jurassic marine sediments in Southern Germany. The rock forms a homogenous unit some ten meters thick. The degree of consolidation of this type of pelitic rock depends mainly on the former load conditions, but is also dependent on the long-term weathering and even on the present exposition. The geomechanical parameters such as shear strength, tensional strength and permeability vary with the state of consolidation and become important when the use is discussed of such rocks for radioactive waste disposal. A tunneling project at the northern escarpment of the Swabian Alb (Southwest Germany) within the Opalinus clay offered the rare opportunity to obtain fresh unweathered rock samples in greater amounts compared to fresh drilling cores from which geomechanical investigations are usually undertaken. Consequently, the results of geomechanical laboratory testings are presented in order to compare here the results of multistep triaxial compression tests, of hydraulic fracturing laboratory tests and of some other tests for rock characterization with the corresponding results of Opalinus clay sites in Switzerland that were investigated by the Swiss Nagra Company for host rock characterization. After a discussion of the relevant state of fresh Opalinus clay, especially of suction pressure conditions and saturation state, the results of triaxial shear tests are presented. Increasing shear deformation at increasing pressure and unchanged water saturation do not result in a significant strength reduction of the Opalinus clay. The rock shows increasing cohesion and stiffness, if multiple loading has repeatedly reached the failure point. Thus there is no increased permeability with continued shearing. Only at the beginning of the shearing process is a temporarily increased permeability to be expected due to dilatation processes. An increased

  17. Development of a method for the comparison of final repository sites in different host rock formations; Weiterentwicklung einer Methode zum Vergleich von Endlagerstandorten in unterschiedlichen Wirtsgesteinsformationen

    Energy Technology Data Exchange (ETDEWEB)

    Fischer-Appelt, Klaus; Frieling, Gerd; Kock, Ingo; and others

    2017-10-15

    The report on the development of a method for the comparison of final repository sites in different host rock formations covers the following issues: influence of the requirement of retrievability on the methodology, study on the possible extension of the methodology for repository sites with crystalline host rocks: boundary conditions in Germany, final disposal concept for crystalline host rocks, generic extension of the VerSi method, identification, classification and relevance weighting of safety functions, relevance of the safety functions for the crystalline host rock formation, review of the methodological need for changes for crystalline rock sites under low-permeability covering; study on the applicability of the methodology for the determination of site regions for surface exploitation (phase 1).

  18. Hydraulic and hydrochemical characterisation of argillaceous rocks

    International Nuclear Information System (INIS)

    1995-01-01

    Throughout the OECD member countries many national programmes on radioactive waste management are considering geological disposal in argillaceous media. In order to determine their suitability for waste disposal, evaluations and understanding of basic physical and chemical processes that govern radionuclides transport through these formations are required. Clay-rich media have a very marked capacity to retard the movement of radionuclides by sorption, filtration and other mechanisms. However, a complicating factor to make quantitative predictions of the performance of clay barriers is our incomplete knowledge of the mechanisms of groundwater and solute transport in compact clays. Application of hydraulic testing and groundwater sampling methods to low and very low permeability rocks, and in particular to argillaceous media, requires modifications in equipment, testing procedures, and interpretation methods. In this context, the NEA Coordinating Group on Site Evaluation and Design of Experiments for Radioactive Waste Disposal (SEDE) established the NEA Working Group on Measurement and Physical Understanding of Groundwater Flow through Argillaceous Media (the Clay Club) to address the many issues associated with this subject. The workshop on hydraulic and hydrochemical characteristics of argillaceous media was hosted by the British Geological Survey in Keyworth, United Kingdom, on 7-9 June 1994

  19. Use of the 14C-PMMA and He-gas methods to characterise excavation disturbance in crystalline rock

    International Nuclear Information System (INIS)

    Autio, J.; Kirkkomaeki, T.; Siitari-Kauppi, M.; Timonen, J.; Laajalahti, M.; Aaltonen, T.; Maaranen, J.

    1999-04-01

    Characterisation of the excavation disturbance caused by boring of experimental full-scale deposition holes in the Research Tunnel at Olkiluoto was carried out successfully by using two novel methods; the 14 C-PMMA and He-gas methods, which were modified and applied for the first time in this type of study. The experience obtained implies that the techniques are feasible and can be used to study similar types of rock excavation disturbance such as that caused by boring with mini discs, a technique which will be used in the underground Hard Rock Laboratory at Aespoe during late 1998 and early 1999. Both of the measurement methods have been in continuous use and the work has included development of both the measuring and interpretation techniques. Use of the 14 C-PMMA method is suggested for studies of rock structure and the spatial distribution of porosity. The 14 C-PMMA method also provides quantitative information about nanometer-range porosity which is beyond the scope of most standard methods of microscopic investigation. The use of He-gas methods are proposed for determining the diffusion coefficient, permeability and complementary porosity of rock samples taken from the disturbed zone. (orig.)

  20. Characterisation of phosphate rocks at kurun mountain, Sudan

    International Nuclear Information System (INIS)

    Abdelgader, G. A. M.

    2014-08-01

    This main objective of this study was to characterise some Sudanese phosphate raw materials collected from Jebel Kurun, located in the eastern part of Nuba Mountain, Western Sudan. The study also aimed to investigate the association between uranium and phosphate and to determine the concentration of some essential elements and trace elements in the phosphate rock. A total of 30 samples were collected from Karun's eastran mountains, near Abujibiha City and have been analyzed for the selected elements using x-ray fluorescence. The obtained results showed that the average concentration of elements was Ca (11.3) and Fe (1.7) as a percentage, while it was Cu (1617.7), Ni (258.4), Pb (185.9), Ti (27.62), V (3779.9), U (160.9), Zn (152.8) and Mn (776.3) in ppm. The average total phosphorus content (analyzed as P O5 %) using UV-visible spectrometer was found to be 30.54%. This could be considered is acceptable percentage for phosphate to be 30.54%. This could be considered is acceptable percentage for phosphate to be used in industrial fertilizers and phosphoric acid production. The average total calcium carbonate was 15.7%. For the elements distribution, uranium found to be more concentrated in the summit of Jebel Kurun, and it displayed a correlation with lead. Furthermore, four groups of association have been noticed, based on elements concentrations.(Author)

  1. Damage-plasticity model of the host rock in a nuclear waste repository

    Energy Technology Data Exchange (ETDEWEB)

    Koudelka, Tomáš; Kruis, Jaroslav, E-mail: kruis@fsv.cvut.cz [Department of Mechanics, Faculty of Civil Engineering, Czech Technical University in Prague, Thákurova 7, 166 29 Prague (Czech Republic)

    2016-06-08

    The paper describes damage-plasticity model for the modelling of the host rock environment of a nuclear waste repository. Radioactive Waste Repository Authority in Czech Republic assumes the repository to be in a granite rock mass which exhibit anisotropic behaviour where the strength in tension is lower than in compression. In order to describe this phenomenon, the damage-plasticity model is formulated with the help of the Drucker-Prager yield criterion which can be set to capture the compression behaviour while the tensile stress states is described with the help of scalar isotropic damage model. The concept of damage-plasticity model was implemented in the SIFEL finite element code and consequently, the code was used for the simulation of the Äspö Pillar Stability Experiment (APSE) which was performed in order to determine yielding strength under various conditions in similar granite rocks as in Czech Republic. The results from the performed analysis are presented and discussed in the paper.

  2. Tourmaline occurrences within the Penamacor-Monsanto granitic pluton and host-rocks (Central Portugal): genetic implications of crystal-chemical and isotopic features

    Science.gov (United States)

    da Costa, I. Ribeiro; Mourão, C.; Récio, C.; Guimarães, F.; Antunes, I. M.; Ramos, J. Farinha; Barriga, F. J. A. S.; Palmer, M. R.; Milton, J. A.

    2014-04-01

    Tourmalinization associated with peraluminous granitic intrusions in metapelitic host-rocks has been widely recorded in the Iberian Peninsula, given the importance of tourmaline as a tracer of granite magma evolution and potential indicator of Sn-W mineralizations. In the Penamacor-Monsanto granite pluton (Central Eastern Portugal, Central Iberian Zone), tourmaline occurs: (1) as accessory phase in two-mica granitic rocks, muscovite-granites and aplites, (2) in quartz (±mica)-tourmaline rocks (tourmalinites) in several exocontact locations, and (3) as a rare detrital phase in contact zone hornfels and metapelitic host-rocks. Electron microprobe and stable isotope (δ18O, δD, δ11B) data provide clear distinctions between tourmaline populations from these different settings: (a) schorl-oxyschorl tourmalines from granitic rocks have variable foititic component (X□ = 17-57 %) and Mg/(Mg + Fe) ratios (0.19-0.50 in two-mica granitic rocks, and 0.05-0.19 in the more differentiated muscovite-granite and aplites); granitic tourmalines have constant δ18O values (12.1 ± 0.1 ‰), with wider-ranging δD (-78.2 ± 4.7 ‰) and δ11B (-10.7 to -9.0 ‰) values; (b) vein/breccia oxyschorl [Mg/(Mg + Fe) = 0.31-0.44] results from late, B- and Fe-enriched magma-derived fluids and is characterized by δ18O = 12.4 ‰, δD = -29.5 ‰, and δ11B = -9.3 ‰, while replacement tourmalines have more dravitic compositions [Mg/(Mg + Fe) = 0.26-0.64], close to that of detrital tourmaline in the surrounding metapelitic rocks, and yield relatively constant δ18O values (13.1-13.3 ‰), though wider-ranging δD (-58.5 to -36.5 ‰) and δ11B (-10.2 to -8.8 ‰) values; and (c) detrital tourmaline in contact rocks and regional host metasediments is mainly dravite [Mg/(Mg + Fe) = 0.35-0.78] and oxydravite [Mg/(Mg + Fe) = 0.51-0.58], respectively. Boron contents of the granitic rocks are low (<650 ppm) compared to the minimum B contents normally required for tourmaline saturation in

  3. Self-sealing of excavation induced fractures in clay host rock

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chun-Liang [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Braunschweig (Germany)

    2015-07-01

    magnitude down to very low levels of 10{sup -19} to 10{sup -21} m{sup 2} even at low confining stresses of 2-4 MPa within short periods of months to years, compared with the long post-closure phase of tens of thousands of years. The very low water permeabilities reached are the same order as that of the intact claystones, indicating that the fractures in the claystones can be completely resealed. The very low water permeabilities do not change significantly during heating and cooling within a temperature range between 20 C and 90 C. This suggests no negative thermal impact on the sealing of the fractures. Before water saturation, the fractures act as conduits for preferential gas flow. However, after water saturation, gas entry and penetration into the resealed fractures in claystone needs certain driving forces to overcome the capillary thresholds. The gas entry/breakthrough pressure is determined by the sealing intensity of the fractures and the confining stress. The gas tests carried out on the highly-resealed claystones show that the gas breakthrough pressures increase with confining stress from low levels of 0.2-1.0 MPa at a low stress of 2 MPa up to 8.3-11.3 MPa at high stresses of 12.7-15.0 MPa corresponding to the rock stress state at a depth of ∝500 m. It is obvious that the breakthrough pressures are still below the applied confining stresses. This important finding implies that the EDZ, even when highly-resealed, will still have the capacity for gas migration with moderate pressures and thus contribute to avoid high pressure build up for fracturing the host rock. Generally speaking, the significant sealing capacities of the claystones hinder water transport and thus radionuclides migration through the fractures, but allow gas migration at moderate pressures without fracturing the host rock. These significant advantages guarantee the long-term integrity and barrier function of the host rock.

  4. Interaction between clay-based sealing components and crystalline host rock

    Science.gov (United States)

    Priyanto, D. G.; Dixon, D. A.; Man, A. G.

    The results of hydraulic-mechanical (H-M) numerical simulation of a shaft seal installed at a fracture zone (FZ) in a crystalline host rock using the finite element method are presented. The primary function of a shaft seal is to limit short-circuiting of the groundwater flow regime via the shaft in a deep geological repository. Two different stages of system evolution were considered in this numerical modelling. Stage 1 simulates the groundwater flow into an open shaft, prior to seal installation. Stage 2 simulates the groundwater flow into the shaft seal after seal installation. Four different cases were completed to: (i) evaluate H-M response due to the interaction between clay-based sealing material and crystalline host rock in the shaft seal structure; (ii) quantify the effect of the different times between the completion of the shaft excavation and the completion of shaft seal installation on the H-M response; and (iii) define the potential effects of different sealing material configurations. Shaft sealing materials include the bentonite-sand mixture (BSM), dense backfill (DBF), and concrete plug (CP). The BSM has greater swelling capacity and lower hydraulic conductivity ( K) than the DBF. The results of these analyses show that the decrease of the pore water pressure is concentrated along the fracture zone (FZ), which has the greatest K. As the time increases, the greatest decrease in pore water pressure is found around the FZ. Following FZ isolation and the subsequent filling of the shaft with water as it floods, the pore water pressure profile tends to recover back to the initial conditions prior to shaft excavation. The majority of the fluids that ultimately saturate the centre of the shaft seal flow radially inwards from the FZ. The time between the completion of the shaft excavation and the completion of shaft seal installation has a significant effect on the saturation time. A shorter time can reduce the saturation time. Since most of the inflow

  5. Age, sedimentary environments, and other aspects of sandstone and related host rocks for uranium deposits

    International Nuclear Information System (INIS)

    1983-01-01

    Project II of the Uranium Geology Working Group was assigned to the study of sedimentary basins and sandstone - type uranium deposits. About 40% of the worlds's uranium resources are contained in sandstone-type deposits, which has led to extensive research. The research was carried out mainly by correspondence, and the results reported by 21 geologists from 10 nations are summarized in this report. It investigated five topics dealing with important aspects of the geology of uranium ores in sandstone host formations: age of host rock; partitioning of uranium between continental and marine sediments; latitude limitation on formation of sandstone deposits; effect of rock formation dip on sandstone ores; usefulness of stable isotope and fluid inclusion studies. The results of studies on these subjects form part of a wider programme of the Working Group, whose final results will be presented at the 27th International Geological Congress in Moscow in 1984

  6. The RRP Project: investigating radionuclide retardation in the host rock

    International Nuclear Information System (INIS)

    Alexander, W.R.; Frieg, B.; Ota, K.; Bossart, P.

    1996-01-01

    The Radionuclide Retardation Project (RRP), which is a joint Nagra/PNC (Power Reactor and Nuclear Fuel Development Corp.) project, has two components: the first (the Excavation Project, EP) looks at the behaviour of radionuclides which are so strongly retarded in the experimental shear zone that they cannot pass through the zones in experimentally reasonable times. In order to determine where radionuclide retardation has occurred in the pore space, as well as the flowpath geometry in the shear zone, the entire injection zone has to be excavated and taken back to the laboratory for analysis of the sites of retardation of the radionuclides. This approach has the advantage of allowing a detailed 3D description of the experimental shear zone. The aim of the second component of the project (Connected Porosities, CP) is to examine the fate of those radionuclides which diffuse out of the main water-conducting features in the shear zone and into the pore spaces of the rock matrix, where they become trapped. This represents a potentially significant retardation mechanism in a repository host rock. (author) 8 figs., refs

  7. Effects of Host-rock Fracturing on Elastic-deformation Source Models of Volcano Deflation.

    Science.gov (United States)

    Holohan, Eoghan P; Sudhaus, Henriette; Walter, Thomas R; Schöpfer, Martin P J; Walsh, John J

    2017-09-08

    Volcanoes commonly inflate or deflate during episodes of unrest or eruption. Continuum mechanics models that assume linear elastic deformation of the Earth's crust are routinely used to invert the observed ground motions. The source(s) of deformation in such models are generally interpreted in terms of magma bodies or pathways, and thus form a basis for hazard assessment and mitigation. Using discontinuum mechanics models, we show how host-rock fracturing (i.e. non-elastic deformation) during drainage of a magma body can progressively change the shape and depth of an elastic-deformation source. We argue that this effect explains the marked spatio-temporal changes in source model attributes inferred for the March-April 2007 eruption of Piton de la Fournaise volcano, La Reunion. We find that pronounced deflation-related host-rock fracturing can: (1) yield inclined source model geometries for a horizontal magma body; (2) cause significant upward migration of an elastic-deformation source, leading to underestimation of the true magma body depth and potentially to a misinterpretation of ascending magma; and (3) at least partly explain underestimation by elastic-deformation sources of changes in sub-surface magma volume.

  8. Interaction between clay-based shaft seal components and crystalline host rock

    International Nuclear Information System (INIS)

    Priyanto, D.; Dixon, D.; Man, A.

    2010-01-01

    Document available in extended abstract form only. The Government of Canada has accepted the Nuclear Waste Management Organization's (NWMO) recommendation of Adaptive Phased Management (APM) as the long-term management approach for Canada's used nuclear fuel. APM ultimately involves the isolation and containment of used nuclear fuel deep in a Deep Geological Repository (DGR). On completion of waste emplacement operation and during repository closure, shaft seals, comprising clay-based shaft seal components, will be installed at strategic locations, such as where significant fracture zones (FZs) are located. The primary function of a shaft seal is to limit and prevent short-circuiting of the groundwater flow regime via the shaft. Currently, at Atomic Energy of Canada Limited's Underground Research Laboratory (URL) a full-scale shaft seal is being constructed at the intersection of a low dipping thrust fault called FZ 2 as part of the overall URL decommissioning activities. Both crystalline rock and sedimentary rock are considered potentially suitable host rocks formations for a DGR. This paper presents the results of numerical simulation of a shaft seal installed in moderately to sparsely fractured crystalline rock (MFR). The shape and thickness of the shaft seal modelled for a DGR in this exercise are similar to the shaft seal at the URL, but in the modelling exercise it is given a larger diameter (i.e. 7.30 m) equal to the assumed diameter of a production shaft of a repository. The seal consists of a blended bentonite-sand (BS) component that is constrained between two massive concrete seals. Dense backfill (DBF) materials are installed above and below the concrete seals (CS). The concrete seals are keyed into the access shaft to better anchor the concrete units in place and in order to restrain the swelling of the bentonite-sand component of the seal as it hydrates. The reference geosphere in the proposed work is MFR similar to the rock conditions

  9. Frictional processes during flank motion at Mount Etna (Italy): experimental characterisation of slip on similar and dissimilar volcanic and sedimentary rocks.

    Science.gov (United States)

    Rozanski, Wojciech; Lavallee, Yan; Kendrick, Jackie; Castagna, Angela; Mitchell, Thomas; Heap, Michael; Vinciguerra, Sergio; Hirose, Takehiro; Dingwell, Donald

    2015-04-01

    The edifice of Mount Etna (Italy) is structurally unstable, exhibiting a near continuous ESE seaward sliding along a set of faults due to interplay between regional tectonics, gravity instability and magma intrusion. Continuous seismic and ground deformation monitoring reveals the resulting large-scale flank motion at variable rates. The mechanisms controlling this faulting kinetic remains, however, poorly constrained. Examination of the fault zones reveals a range of rock types along the different fault segments: fresh and altered basalt, clay and limestone. As lithological contrasts can jeopardise the structural stability of an edifice, we experimentally investigate the frictional properties of these rocks using low- to high-velocity-rotary shear tests on similar and dissimilar rocks to better understand episodes of slow flank motion as well as rapid and catastrophic sector collapse events. The first set of experiments was performed at velocities up to 1.2 m/s and at normal stresses of 1.5 MPa, commensurate with depths of the contacts seen in the Etna edifice. Friction experiments on clay gouge shows the strong rate-weakening dependence of slip in this material as well as the release of carbon dioxide. Friction experiments on solid rocks show a wider range of mechanical behaviour. At high velocity (>0.6 m/s) volcanic rocks tend to melt whereas the clay and limestone do not; rather they decarbonate, which prevents the rock from achieving the temperature required for melting. Experiments on dissimilar rocks clearly show that composition of host rocks affects the composition and viscosity of the resultant frictional melt, which can have a dramatic effect on shear stress leading to fault weakening or strengthening depending on the combination of host rock samples. A series of low- to moderate-slip velocity experiments is now being conducted to complement our dataset and provide a more complete rock friction model applicable to Mount Etna.

  10. ENSI - Evaluation of NAGRA’s planned investigation of Brown Dogger host rock - Expert report

    International Nuclear Information System (INIS)

    Bitterli-Dreher, P; Burkhalter, R.

    2011-06-01

    This report published by the Swiss National Safety Inspectorate ENSI discusses the reports published on the Brown Dogger host rock formations and the investigations planned as part of Phase 2 of the planning process for deep repositories for low and medium-active nuclear wastes. After a review of the tasks to be carried out, two expert reports are introduced. In the first report, Dr. Peter Bitterli-Dreher looks at the geological situation in central Europe and rock conditions in northern Switzerland. The situation in the Dogger formations with their calcium carbonate and clay-like components in various locations in northern Switzerland are discussed, including water flow in the rocks. The second report from Dr. Reto Burkhalter also discusses the Brown Dogger formations and comments on the investigations proposed by NAGRA in detail. Work yet to be planned is looked at

  11. Review of potential host rocks for radioactive waste disposal in the Piedmont province of North Carolina

    International Nuclear Information System (INIS)

    Butler, J.R.

    1980-10-01

    This report reviews the geology of the Piedmont province in North Carolina, emphasizing those features most pertinent to selection of potential host rocks for radioactive waste disposal. Discussion of criteria for selection indicates that the outcrop area of the rock body, probable homogeneity, low incidence of fractures, and low permeability are among the prime considerations. Application of the criteria leads to the selection of three large granite batholiths (Castalia, Churchland, and Rolesville) as potential field study areas. The report has an extensive bibliography

  12. Chemical buffering capacity of clay rock

    International Nuclear Information System (INIS)

    Beaucaire, C.; Pearson, F.J.; Gautschi, A.

    2004-01-01

    The long-term performance of a nuclear waste repository is strongly dependent on the chemical properties of the host rock. The host rock establishes the chemical environment that determines such important performance attributes as radionuclide solubilities from the waste and the transport rates from the repository to the accessible environment. Clay-rich rocks are especially favourable host rocks because they provide a strong buffering capacity to resist chemical changes prompted either internally, by reactions of the waste itself and emplacement materials, or externally, by changes in the hydrologic systems surrounding the host rock. This paper will focus on three aspects of the stability of clay-rich host rocks: their ability to provide pCO 2 and redox buffering, and to resist chemical changes imposed by changes in regional hydrology and hydro-chemistry. (authors)

  13. Thermal Analysis of a Nuclear Waste Repository in Argillite Host Rock

    Science.gov (United States)

    Hadgu, T.; Gomez, S. P.; Matteo, E. N.

    2017-12-01

    Disposal of high-level nuclear waste in a geological repository requires analysis of heat distribution as a result of decay heat. Such an analysis supports design of repository layout to define repository footprint as well as provide information of importance to overall design. The analysis is also used in the study of potential migration of radionuclides to the accessible environment. In this study, thermal analysis for high-level waste and spent nuclear fuel in a generic repository in argillite host rock is presented. The thermal analysis utilized both semi-analytical and numerical modeling in the near field of a repository. The semi-analytical method looks at heat transport by conduction in the repository and surroundings. The results of the simulation method are temperature histories at selected radial distances from the waste package. A 3-D thermal-hydrologic numerical model was also conducted to study fluid and heat distribution in the near field. The thermal analysis assumed a generic geological repository at 500 m depth. For the semi-analytical method, a backfilled closed repository was assumed with basic design and material properties. For the thermal-hydrologic numerical method, a repository layout with disposal in horizontal boreholes was assumed. The 3-D modeling domain covers a limited portion of the repository footprint to enable a detailed thermal analysis. A highly refined unstructured mesh was used with increased discretization near heat sources and at intersections of different materials. All simulations considered different parameter values for properties of components of the engineered barrier system (i.e. buffer, disturbed rock zone and the host rock), and different surface storage times. Results of the different modeling cases are presented and include temperature and fluid flow profiles in the near field at different simulation times. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and

  14. Study on high-resolution sequence stratigraphy framework of uranium-hosting rock series in Qianjiadian sag

    International Nuclear Information System (INIS)

    Chen Fanghong; Zhang Mingyu

    2005-01-01

    The ore-hosting Yaojia Formation is composed of a set of braided stream medium-fine grained sediments. Guided by the basic theory of high-resolution sequence stratigraphy, and based on the core observation, the analysis of chemical composition of rocks, and data of natural potential logging and apparent resistivity logging, the authors have set up the high-resolution sequence stratigraphy framework of the ore-hosting Yaojia Formation, and discussed the relation of the stratigraphic structure of the middle cycle, as well as the paleotopography, the micro-facies to the formation of uranium deposit. (authors)

  15. The Ypresian clays as alternative host rock for radioactive waste disposal in Belgium. A transferability study

    International Nuclear Information System (INIS)

    Van Baelen, Herve; Wouters, Laurent; Brassinnes, Stephane; Van Geet, Maarten; Vandenberghe, Noel

    2012-01-01

    Document available in extended abstract form only. For the long-term management of high-level and/or long-lived radioactive waste, ONDRAF/NIRAS advises deep geological repository in a plastic clay host rock. Since the seventies, Oligocene Boom Clay has been extensively studied for this purpose and is, in the Belgian context, considered as the reference host rock with Mol as the reference site for the RD and D. The alternative host rock, the Ypresian clays, has been studied for their basic properties, from the late nineties onwards, with Doel as reference site. This study aims at determining to which extent methodologies, knowledge and know-how can be transferred from Boom Clay to the Ypresian clays, in order to enhance the knowledge of this alternative without excessive research efforts. It evaluates the present knowledge of the Ypresian clays and figures out which elements are sufficiently known and understood, which elements of the Boom Clay can be reused and which need additional research. The Ypresian clays refer to a nearly continuous sequence of non-indurated, clayey layers, deposited early in the Eocene, in an open marine basin. It has a total thickness of 100 m or more and, in the area of interest, it occurs at a few hundreds of meters depth. Apart from a very slight tilt to the north, no major structures are known to affect the Ypresian clays in the investigated area. The lateral continuity inside the Ypresian clays might, however, be compromised by the potential occurrence of small-scale intra-formational faults. Two drilling campaigns, carried out in the framework of potential radioactive waste disposal, allowed to collect new data and describe and compare the Ypresian clays relative to Boom Clay. The grain size distribution of both clays is comparable. Although the minerals they are composed of are the same, the relative proportions within the clay fraction are significantly different, the Ypresian clays containing more smectite and swelling mixed

  16. Engineering rock mass classification of the Olkiluoto investigation site

    Energy Technology Data Exchange (ETDEWEB)

    Aeikaes, K. [ed.; Hagros, A.; Johansson, E. [Saanio and Riekkola Consulting Engineers, Helsinki (Finland)] [and others

    2000-06-01

    Olkiluoto in Eurajoki is being investigated as a possible site for the final disposal of spent nuclear fuel from the Finnish nuclear power plants. The selection of the depth, placement and layout of the repository is affected by the constructability of the bedrock. The constructability, in turn, is influenced by several properties of the host rock, such as its Ethology, the extent of fracturing, its hydrogeological properties and rock engineering characteristics and also by the magnitude and orientation of the in situ stresses and the chemistry of the groundwater. The constructability can be evaluated by the application of a rock classification system in which the properties of the host rock are assessed against common rock engineering judgements associated with underground construction. These judgements are based partly on measurements of in situ stresses and the properties of the bedrock determined from rock samples, but an important aspect is also the practical experience which has been gained during underground excavation in similar conditions and rock types. The aim of the engineering rock mass classification was to determine suitable bedrock volumes for the construction of the repository and has used data from the site characterisation programme carried out at Olkiluoto, which consisted of both surface studies and borehole investigations. The classification specifies three categories of constructability - normal, demanding and very demanding. In addition, rock mass quality has also been classified according to the empirical Q-system to enable a comparison to be made. The rock mass parameters that determine the constructability of the bedrock at Olkiluoto depend primarily on the depth and the Ethology, as well as on whether construction takes place in intact or in fractured rock. The differences in the characteristics of intact rock within a single rock type have been shown to be small. The major lithological unit at Olkiluoto, the mica gneiss, lies in the

  17. Microbiologically mediated processes in a repository sited in a clay host rock

    International Nuclear Information System (INIS)

    Schwyn, B.; Leupin, O. X.; Bagnoud, A.; Bernier-Latmani, R.

    2012-01-01

    Document available in extended abstract form only. Because of their favourable retention properties for radionuclides, clay-rich sediments are being considered in Switzerland as host rocks for the geological disposal of high, intermediate- and low-level radioactive waste. Compacted bentonite is foreseen as backfill material in the high level waste repository whereas for intermediate- and low-level waste the near field will mainly consist of cementitious material. The evolution of both types of repositories, which includes re-saturation, heat generation (only high level waste), near field degradation, gas production and radionuclide release may be impacted by microbial activity and vice versa. In this respect questions arise such as: - Are microorganisms present in a repository and its host rock? - Under which condition are microorganisms active in and around a repository? - In which processes are microorganisms involved? Various in situ experiments in a wide range of geological environments have evidenced the presence of microorganisms. Whether the microorganisms found in these in situ experiments are indigenous or introduced by drilling or/and excavation activities is still controversial. However, recent findings suggest the presence of indigenous microorganisms in Opalinus Clay. To conclusively answer the question about the origin of microorganisms, an international investigation programme has been launched to probe rock samples from the Underground Rock Laboratory at Mont Terri. So far, no metabolic activity has been observed in undisturbed clay rocks. Such activity may have ceased during diagenetic compaction of the sediment as suggested by the pore water composition measured in the Callovian-Oxfordian clayey formation of Bure (France). For the safety case of a repository the origin of microorganisms is of minor importance compared to the understanding of the conditions under which they might be metabolically active. Pore size distribution and connectivity can

  18. The origin of groundwater salinity in granitic rocks: identification and characterisation of chloride sources

    International Nuclear Information System (INIS)

    Savoye, Sebastien

    1998-01-01

    This research thesis aims at clearly identifying the possible origins of chlorine in solution in underground waters in a granitic environment, and is thus a first step in the prediction of concentration of dissolved compounds in waters in crystalline environment, with respect to the geological context. In a first part, the author proposes a synthetic and critical overview of knowledge and previous studies: definition of the term 'salinity', presentation of geochemical tracers, presentation of available data on potential chlorine sources in granitic rocks. The author then describes the experimental protocols and studied sites, reports results of the characterisation of different chlorine tanks performed on samples from each studied site. Based on mass assessment calculations and on the use of tracers, the author finally discusses the contribution of each of the chlorine tanks to the salinity of underground waters [fr

  19. Characterisation of fracture network and groundwater preferential ...

    African Journals Online (AJOL)

    Characterisation of fractured rocks and evaluation of fracture connectivity are essential for the study of subsurface flow and transport in fractured rock aquifers. In this study, we use a new method to present fracture networks and analyse the connectivity of the fractures, based on the technique of randomly-generated ...

  20. Rock suitability classification RSC 2012

    Energy Technology Data Exchange (ETDEWEB)

    McEwen, T. (ed.) [McEwen Consulting, Leicester (United Kingdom); Kapyaho, A. [Geological Survey of Finland, Espoo (Finland); Hella, P. [Saanio and Riekkola, Helsinki (Finland); Aro, S.; Kosunen, P.; Mattila, J.; Pere, T.

    2012-12-15

    This report presents Posiva's Rock Suitability Classification (RSC) system, developed for locating suitable rock volumes for repository design and construction. The RSC system comprises both the revised rock suitability criteria and the procedure for the suitability classification during the construction of the repository. The aim of the classification is to avoid such features of the host rock that may be detrimental to the favourable conditions within the repository, either initially or in the long term. This report also discusses the implications of applying the RSC system for the fulfilment of the regulatory requirements concerning the host rock as a natural barrier and the site's overall suitability for hosting a final repository of spent nuclear fuel.

  1. Rock suitability classification RSC 2012

    International Nuclear Information System (INIS)

    McEwen, T.; Kapyaho, A.; Hella, P.; Aro, S.; Kosunen, P.; Mattila, J.; Pere, T.

    2012-12-01

    This report presents Posiva's Rock Suitability Classification (RSC) system, developed for locating suitable rock volumes for repository design and construction. The RSC system comprises both the revised rock suitability criteria and the procedure for the suitability classification during the construction of the repository. The aim of the classification is to avoid such features of the host rock that may be detrimental to the favourable conditions within the repository, either initially or in the long term. This report also discusses the implications of applying the RSC system for the fulfilment of the regulatory requirements concerning the host rock as a natural barrier and the site's overall suitability for hosting a final repository of spent nuclear fuel

  2. Basic investigation and analysis for preferred host rocks and natural analogue study area with reference to high level radioactive waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Jeong Ryul; Park, J. K.; Hwang, D. H.; Lee, J. H.; Yun, H. S.; Kim, D. Y.; Park, H. S.; Koo, S. B.; Cho, J. D.; Kim, K. E. [Korea Inst. of Geology, Mining and Materials, Taejon (Korea, Republic of)

    1997-12-01

    The purpose of this study is basic investigation and analysis for preferred host rocks and natural analogue study area to develope underground disposal technique of high level radioactive waste in future. The study has been done for the crystalline rocks(especially granitic rocks) with emphasis of abandoned metallic mines and uranium ore deposits, and for the geological structure study by using gravity and aeromagnetic data. 138 refs., 54 tabs., 130 figs. (author)

  3. Evaluation of possible host rocks for China's high level radioactive waste repository and the progress in site characterization at the Beishan potential site in NW China's Gansu province

    International Nuclear Information System (INIS)

    Wang Ju; Jin Yuanxin; Chen Zhangru; Chen Weiming; Wang Wenguang

    2000-01-01

    Evaluation of possible host rocks for China's high level radioactive waste repository is summarized in this paper. The distribution and characteristics of granite, tuff, clay stone, salt and loess in China are described, while maps showing the distribution of host rocks are presented. Because of the wide distribution, large scale, good heat conductivity and suitable mechanical properties, granite is considered as the most potential host rock. Some granite bodies distributed in NW China, SW China, South China and Inner Mongolia have been selected as potential areas. Detailed site characterization at Beishan area, Gansu Province NW China is in progress

  4. Nagra technical report 14-02, Geological basics - Dossier VI - Barrier properties of proposed host rock sediments and neighbouring rock; SGT Etappe 2: Vorschlag weiter zu untersuchender geologischer Standortgebiete mit zugehörigen Standortarealen für die Oberflächenanlage -- Geologische Grundlagen -- Dossier VI -- Barriereneigenschaften der Wirt- und Rahmengesteine

    Energy Technology Data Exchange (ETDEWEB)

    Gautschi, A.; Deplazes, G.; Traber, D.; Marschall, P. [National Cooperative for the Disposal of Radioactive Waste (NAGRA), Wettingen (Switzerland); Mazurek, M.; Gimmi, T.; Maeder, U. [Institute of Geological Sciences, University of Berne, Berne (Switzerland)

    2014-12-15

    This dossier is the sixth of a series of eight reports concerning the safety and technical aspects of locations for the disposal of radioactive wastes in Switzerland. It discusses the barrier properties of the proposed host rock sediments and neighbouring rock layers. The mineralogical composition of the host rocks are discussed as are their pore densities and hydrological properties. Diffusion aspects are discussed. The aquifer systems in the proposed depository areas and their classification are looked at. The barrier properties of the host rocks and those of neighbouring sediments are discussed. Finally, modelling concepts and parameters for the transport of radionuclides in the rocks are discussed.

  5. Simulation of hydraulic disturbances caused by the underground rock characterisation facility in Olkiluoto, Finland

    International Nuclear Information System (INIS)

    Loefman, J.; Ferenc, M.

    2004-01-01

    Spent fuel from the Finnish nuclear power plants will be disposed of in a repository to be excavated in crystalline bedrock at a depth of 400-700 metres in Olkiluoto. The extensive site investigations carried out since the early 1980's will next focus on the construction of an underground rock characterisation facility (ONKALO) in 2004-2010. The open tunnel system will constitute a major hydraulic disturbance for the site's groundwater conditions for hundreds of years. Especially, inflow of groundwater into the tunnels results in a drawdown of groundwater table and upcoming of deep saline groundwater, which the present study aimed to assess by means of a 3D finite element simulation. The modelled bedrock volume, which horizontally covered the whole Olkiluoto island, was conceptually divided into hydraulic units, planar fracture zones and sparsely fractured rock between the zones, which were both separately treated as porous media. The geometry of the fracture zones was based on the geological bedrock model. Simulations showed that without engineering measures (e.g. grouting) taken to limit inflow of groundwater into the open tunnels, the hydraulic disturbances could be drastic. The tunnels draw groundwater from all directions in the bedrock. A major part of inflow comes from the well-conductive subhorizontal fracture zones intersected by the access tunnel and the shaft. The simulations show that the resulting drawdown of groundwater table may be from tens to hundreds of metres and the depressed area may extend over the area of the island. The results also indicate that the salinity of groundwater is gradually rising around and below the tunnel system, and locally concentration (TDS) may rise rather high in the vicinity of the tunnels. However, the disturbances can significantly be reduced by the grouting of rock. (orig.)

  6. Hydro-mechanical modelling of a shaft seal in crystalline and sedimentary host rock media using COMSOL

    Energy Technology Data Exchange (ETDEWEB)

    Priyanto, D.G. [Atomic Energy of Canada Limited, Pinawa, MB (Canada)

    2011-07-01

    Shaft seals are components of the engineered barriers system considered for closure of a Deep Geological Repository (DGR). These seals would be installed in strategic locations of the shafts, where significant fracture zones (FZ) are located and would serve to limit upward flow of groundwater from the repository level towards the surface. This paper presents the results of hydro-mechanical (HM) numerical modelling exercises to evaluate the performance of a shaft seal using a finite element computer code, COMSOL. This study considered a variety of host geological media as part of generic assessments of system evolution in a variety of environments including five hypothetical sedimentary and crystalline host rock conditions. Four simulations of a shaft seal in different sedimentary rocks were completed, including: shale with isotropic permeability; shale with anisotropic permeability; limestone with isotropic permeability; and limestone with anisotropic permeability. The other simulation was a shaft seal in crystalline rock with isotropic permeability. Two different stages were considered in these HM simulations. Stages 1 and 2 simulated the groundwater flow into an open shaft and after installation of shaft sealing components, respectively. As expected, the models were able to simulate that installation of the shaft seal limits groundwater flow through the shaft. Based on the conditions and assumptions defined for the host media and fracture features examined in this study, the following conclusions can be drawn from the results of the numerical modelling exercises. A shaft that remained open for a longer time was beneficial with respect to delaying of seal saturation because it could reduce the groundwater flow rate around the fracture zone. Delaying saturation time indicates slower movement of the groundwater or other substances that may be transported with the groundwater. The core of the shaft seal (i.e., the bentonite-sand mixture (BSM)) became fully saturated

  7. Conceptual and safety-related questions in the final storage of radioactive waste - a comparison of various types of host rock

    International Nuclear Information System (INIS)

    Kleemann, U.

    2005-01-01

    The German Federal Office for Radiation Protection (BfS) in early November published the synthesis report (BfS 2005) about the conceptual and safety-related specific questions associated with the final storage of radioactive waste. In addition to a condensed version of twelve individual projects, the report contains a description of the results of the peer review and the workshops carried out, in particular an evaluation comparing different types of host rock in Germany. The whole project constitutes a comprehensive documentation of the current state of the art. Findings are expressed at a general level referring neither to the suitability of any specific repository site nor to that of salts as a repository formation, but covering all potential repository formations in deep geologic strata in Germany. The limits to and possibilities of, generic comparisons of various types of host rock are shown. It si seen that, in principle, none of the host rock varieties in Germany would be preferable to others. Numerous problems can be solved only for specific sites, thus requiring site comparisons. While some questions indicate a need for regulatory treatment, the need for basic research is considered to be low. The contribution presents the main findings made in each of the specific projects and the evaluations by the Office. (orig.)

  8. Physical properties of uranium host rocks and experimental drilling at Long Park, Montrose County, Colorado. Final report

    International Nuclear Information System (INIS)

    Manger, G.E.; Gates, G.L.; Cadigan, R.A.

    1975-01-01

    A core-drilling study in uranium host rocks of the Jurassic Morrison Formation in southwestern Colorado attempted to obtain samples of host rock in its natural state. Three holes were drilled, holes and core were logged for radioactivity and electrical properties. Samples were analyzed for physical and chemical properties. Drilling results suggest that drilling with dried air yields core with least contamination at least cost. Drilling with oil results in maximum core recovery but also maximum cost and significant core contamination. Drilling with water results in contamination and loss of original pore water. A factor group of variables present are: Those positively related to uranium mineralization are poor sorting, percent by weight clay, percent of pore space containing water; negatively related variables are median grain size (mm), electrical resistivity, permeability. Optimum depth to locate ore seems to be at the top of the pore water capillary circulation zone, below the dehydrated no-capillary-circulation zone

  9. Far-field sorption data bases for performance assessment of a L/ILW repository in an undisturbed Palfris marl host rock

    International Nuclear Information System (INIS)

    Bradbury, M.H.; Baeyens, B.

    1997-12-01

    A Palfris marl formation at Wellenberg (Gemeinde Wolfenschiessen, NW) has been chosen by NAGRA as a potential repository site for low- and intermediate-level radioactive waste, L/ILW. In the coming years a series of performance assessment studies will be performed for this site. One set of key data required for such safety analysis calculations is sorption data bases (SDB) for safety relevant radionuclides in the far-field. The purpose of this report is to describe the procedures used to generate sorption data bases appropriate for the in situ conditions existing along the different potential flow paths in an undisturbed marl host rock formation. An important aim was to document the sources of sorption data used and, in particular, the processes by which data selections were mad.e. The main guiding principles here were 'transparency' and 'traceability'. Inherent within this whole process is also the justification for, and defensibility of, the selected values. Much of the sorption data used to generate the SDB for marl came from the open literature. A major part of this report is concerned with describing the procedures whereby these initial literature values are modified so that they apply to the actual marl mineralogies and groundwater chemistries. The resulting 'reference R d values' are then further modified using so called Lab -> Field transfer factors to produce sorption values which are appropriate to the in situ bulk rock conditions. The Lab -> Field transfer factors attempt to correct for the differences in sorption site availability between the crushed rock state used in batch tests and the intact rock state existing in reality in the host rock. There are two main groundwater chemistries and five characteristic mineralogical compositions which cover the three broad types of flow paths which have been identified in the Palfris marl formation. In principle the methodology described here to construct sorption data bases for marl is applicable to any type of

  10. Far-field sorption data bases for performance assessment of a L/ILW repository in an undisturbed Palfris marl host rock

    Energy Technology Data Exchange (ETDEWEB)

    Bradbury, M.H.; Baeyens, B. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-12-01

    A Palfris marl formation at Wellenberg (Gemeinde Wolfenschiessen, NW) has been chosen by NAGRA as a potential repository site for low- and intermediate-level radioactive waste, L/ILW. In the coming years a series of performance assessment studies will be performed for this site. One set of key data required for such safety analysis calculations is sorption data bases (SDB) for safety relevant radionuclides in the far-field. The purpose of this report is to describe the procedures used to generate sorption data bases appropriate for the in situ conditions existing along the different potential flow paths in an undisturbed marl host rock formation. An important aim was to document the sources of sorption data used and, in particular, the processes by which data selections were mad.e. The main guiding principles here were `transparency` and `traceability`. Inherent within this whole process is also the justification for, and defensibility of, the selected values. Much of the sorption data used to generate the SDB for marl came from the open literature. A major part of this report is concerned with describing the procedures whereby these initial literature values are modified so that they apply to the actual marl mineralogies and groundwater chemistries. The resulting `reference R{sub d} values` are then further modified using so called Lab -> Field transfer factors to produce sorption values which are appropriate to the in situ bulk rock conditions. The Lab -> Field transfer factors attempt to correct for the differences in sorption site availability between the crushed rock state used in batch tests and the intact rock state existing in reality in the host rock. There are two main groundwater chemistries and five characteristic mineralogical compositions which cover the three broad types of flow paths which have been identified in the Palfris marl formation. In principle the methodology described here to construct sorption data bases for marl is applicable to any

  11. Rock stress measurements in ONKALO underground characterisation facility at Olkiluoto at depth of 120 m

    International Nuclear Information System (INIS)

    Fecker, E.

    2007-04-01

    In November and December 2006 overcoring stress measurements have been conducted in the boreholes ONK-PP74, ONK-PP75 and ONK-PP77 in a niche of the access tunnel of the ONKALO underground characterisation facility at the Olkiluoto site. Measurements have been done using the CSIRO 3D stress measuring cell. This cell is one of the mostly used cells in the whole world for estimation of the state of stress in rock when doing the borehole measurements. The boreholes are at a depth of about 120 m under the ground surface. The rock where the measurements have been conducted is a foliated migmatitic gneiss (subtypes veined and diatexitic gneiss). Parallel to the overcoring measurements a glue test has been conducted in the laboratory to check the quality of the bonding of the stress cells to the rock. The result showed that the glue makes a good contact between the rock and the stress cell, but air bubbles, which have normally been observed within the glue and at the edges, proved this time to be disadvantageous. Normally such air bubbles have dimensions of about one millimetre, but sometimes certain bubbles may become notably bigger. In the ONKALO overcored probes sawn apart such air bubbles were found both in wet and dry probe conditions. In the test series eight stress measurements have been provided, three of them failed for technical reasons. At one of these three tests the glue has extruded too early, at the other two tests the overcoring was not conducted deep enough. At the remaining five tests in spite of the glue test results a calculation of the stress tensor could be made. Four of these five measurements can be seen as relatively successful. The results of these measurements show a major principal stress of 14.8 MPa in average, trending northwest - southeast, and with a dipping of 11 degrees in average. (orig.)

  12. THM-coupled modeling of selected processes in argillaceous rock relevant to rock mechanics

    International Nuclear Information System (INIS)

    Czaikowski, Oliver

    2012-01-01

    Scientific investigations in European countries other than Germany concentrate not only on granite formations (Switzerland, Sweden) but also on argillaceous rock formations (France, Switzerland, Belgium) to assess their suitability as host and barrier rock for the final storage of radioactive waste. In Germany, rock salt has been under thorough study as a host rock over the past few decades. According to a study by the German Federal Institute for Geosciences and Natural Resources, however, not only salt deposits but also argillaceous rock deposits are available at relevant depths and of extensions in space which make final storage of high-level radioactive waste basically possible in Germany. Equally qualified findings about the suitability/unsuitability of non-saline rock formations require fundamental studies to be conducted nationally because of the comparatively low level of knowledge. The article presents basic analyses of coupled mechanical and hydraulic properties of argillaceous rock formations as host rock for a repository. The interaction of various processes is explained on the basis of knowledge derived from laboratory studies, and open problems are deduced. For modeling coupled processes, a simplified analytical computation method is proposed and compared with the results of numerical simulations, and the limits to its application are outlined. (orig.)

  13. Aespoe Hard Rock Laboratory. Characterisation methods and instruments. Experiences from the construction phase

    International Nuclear Information System (INIS)

    Almen, Karl-Erik; Stenberg, Leif

    2005-12-01

    This report describes the different investigation methods used during the Aespoe HRL construction phase which commenced 1990 and ended 1995. The investigation methods are described with respect to performance, errors, uncertainty and usefulness in determined, analysed and/or calculated parameter values or other kind of geoscientific information. Moreover, other comments of the different methods, like those related to the practical performance of the measurements or tests are given. The practical performance is a major task as most of the investigations were conducted in parallel with the construction work. Much of the wide range of investigations carried out during the tunnelling work required special efforts of the personnel involved. Experiences and comments on these operations are presented in the report. The pre-investigation methods have been evaluated by comparing predictions based on pre-investigation models with data and results from the construction phase and updated geoscientific models. In 1997 a package of reports describe the general results of the pre-investigations. The investigation methods are in this report evaluated with respect to usefulness for underground characterisation of a rock volume, concerning geological, geohydrological, hydrochemical and rock mechanical properties. The report describes out opinion of the methods after the construction phase, i.e. the same platform of knowledge as for the package of reports of 1997. The evaluation of usefulness of the underground investigation methods are structured according to the key issues used for the preinvestigation modelling and predictions, i.e. Geological-structural model, Groundwater flow (hydrogeology), Groundwater chemistry (hydrochemistry), Transport of solutes and Mechanical stability models (or rock mechanics). The investigation methods selected for the different subjects for which the predictions were made are presented. Some of the subjects were slightly modified or adjusted during

  14. Aespoe Hard Rock Laboratory. Characterisation methods and instruments. Experiences from the construction phase

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-12-15

    This report describes the different investigation methods used during the Aespoe HRL construction phase which commenced 1990 and ended 1995. The investigation methods are described with respect to performance, errors, uncertainty and usefulness in determined, analysed and/or calculated parameter values or other kind of geoscientific information. Moreover, other comments of the different methods, like those related to the practical performance of the measurements or tests are given. The practical performance is a major task as most of the investigations were conducted in parallel with the construction work. Much of the wide range of investigations carried out during the tunnelling work required special efforts of the personnel involved. Experiences and comments on these operations are presented in the report. The pre-investigation methods have been evaluated by comparing predictions based on pre-investigation models with data and results from the construction phase and updated geoscientific models. In 1997 a package of reports describe the general results of the pre-investigations. The investigation methods are in this report evaluated with respect to usefulness for underground characterisation of a rock volume, concerning geological, geohydrological, hydrochemical and rock mechanical properties. The report describes out opinion of the methods after the construction phase, i.e. the same platform of knowledge as for the package of reports of 1997. The evaluation of usefulness of the underground investigation methods are structured according to the key issues used for the preinvestigation modelling and predictions, i.e. Geological-structural model, Groundwater flow (hydrogeology), Groundwater chemistry (hydrochemistry), Transport of solutes and Mechanical stability models (or rock mechanics). The investigation methods selected for the different subjects for which the predictions were made are presented. Some of the subjects were slightly modified or adjusted during

  15. Review of potential host rocks for radioactive wasste disposal in the southeast United States: Triassic basin subregion

    International Nuclear Information System (INIS)

    1980-10-01

    Based on an evaluation of existing information, areas were identified within the Triassic basins of the southeastern United States with geologic properties considered favorable for containment of radioactive waste. The study region included both exposed and buried Triassic basins from Maryland to Georgia. These basins are long, narrow northeast-trending troughs filled with continental deposits derived from Paleozoic and Precambrian metamorphic and igneous rocks bordering the basins. The rocks are predominantly red in color and consist mainly of fanglomerates, conglomerates, arkosic sandstones, siltstones, claystones, shales, and argillites. The investigation identified 14 exposed and 5 buried basins within the study region. Candidate areas for further investigation were identified which meet the broad general criteria for tectonic stability, slow ground water movement, and long flow paths to the biosphere. These include: the Danville Triassic Basin in Virginia; the Dan River, Durham, and Wadesboro Triassic Basins in North Carolina; and the buried Florence and Dunbarton Triassic Basins in South Carolina. Other rock types in the southeast may prove more or less suitable as host rocks for a repository, but the available data suggest that the argillaceous Triassic rocks offer sufficient promise to be considered for additional study

  16. Basic feature of host rock and its relation to the formation of leachable sandstone type uranium deposit in Shihongtan

    International Nuclear Information System (INIS)

    Quan Zhigao; Zhang Jiamin; Ji Haijun; Sun Yanhuan; Zhang Fa

    2012-01-01

    Basic feature of sedimentology and petrology and lithogeochemistry of middle Jurassic Xishanyao formation were discussed for Shihongtan uranium deposit in the paper. The relation between host rock and ore formation was analysed. It is indicated that the formation of Shihongtan uranium deposit de-ponds on the following host features in sedimentology, petrology, lithogeochemistry and the intense oxidized epigenetic alteration under hot dry climate condition during the formation of peneplain caused by the slow tilting uplift. (authors)

  17. Subsurface geology, geochemistry, and water flow at a Rock Characterisation Facility (RCF) at Sellafield. Supplementary proof of evidence

    International Nuclear Information System (INIS)

    Haszeldine, R.S.

    1996-01-01

    Detailed comments are made on behalf of Greenpeace Ltd in a Supplementary Proof of Evidence presented to a Planning Inquiry in 1995 in support of their objections to an application by UK Nirex Ltd for permission to construct an underground Rock Characterisation Facility (RCF) at a site near Sellafield. The RCF is part of an investigation by Nirex into a suitable site for the disposal of radioactive waste. The principal points of disagreement with Nirex concern: the promise of the site; the oxidation state of the natural groundwater and uranium solubility; effects of possible future earthquakes; the interpretation of flow potential; the application of fluid flow modelling and the parameters used in it. (1 figure; 21 references). (UK)

  18. Physical Matrix Characterisation: Studies of Crystalline Rocks and Consolidated Clays by PMMA Method and Electron Microscopy as Support of Diffusion Analyses

    Energy Technology Data Exchange (ETDEWEB)

    Siitari-Kauppi, M.; Leskinen, A.; Kelokaski, A.; Togneri, L.; Alonso, U.; Missana, T.; Garcia-Gutierrez, M.; Patelli, A.

    2007-07-01

    Crystalline rock and consolidated clay are both considered adequate host rocks for a high-level radioactive waste deep geological repository (HLWR). Over the extended periods of HLWR operation, long-lived radionuclides (RN) may be released from the fuel and migrate to the geo/biosphere. To predict the fate of contaminants and to assess the safety of the host rock, it is very important to determine transport parameters, as diffusion coefficients, and to relate them to the physical properties of the barriers, as connected porosity. In heterogeneous materials, it is also a major task to describe the transport at the mineral scale evaluating diffusion coefficients and mineral-specific porosities on single minerals. The main objective of this study was to determine within granite and consolidated clay, the connective porosity and mineral-specific porosities by poly-methylmethacrylate (PMMA) autoradiography method. Scanning electron microscopy and energy-dispersive X-ray analyses (FESEM/EDS) were performed in order to study the pore apertures of porous regions in greater detail and to identify the corresponding minerals. By the novel application of the nuclear ion beam technique Rutherford Backscattering Spectrometry (RBS) apparent diffusion coefficients were determined at mineral scale. Finally, the porosity results were used to evaluate the effective diffusion coefficients and retention parameters of single minerals in different granite samples and consolidated clays. (Author) 42 refs.

  19. Representation and judgement of possible host rock formations and areas under consideration of geology and safety

    International Nuclear Information System (INIS)

    2005-08-01

    This comprehensive report issued by the Swiss National Cooperative for the Disposal of Radioactive Waste NAGRA takes a look at the representation and judgement of possible host rock formations and areas as far as safety and geological aspects are concerned. Nagra has to demonstrate the basic feasibility of the safe disposal of spent fuel (SF), vitrified high-level waste (HLW) and long-lived intermediate-level waste (ILW) in a deep geological repository, The report shows which possibilities for the disposal of SF, HLW and ILW exist in Switzerland and summarises the current state of general academic and applied geo-scientific research as well as the project-specific knowledge base that has been developed by Nagra over the past 30 years. The descriptions and assessments of the potential host rocks and areas are based on attributes that take into account experience gained both in Switzerland and abroad and are in agreement with international practice. An assessment of potential siting areas is looked at, in view of the preparation of a General Licence application, Nagra will also have to consider land-use planning and socio-economic aspects. This will be carried out in the next step according to the Sectoral Plan for Geological Disposal under the guidance of the relevant Swiss authorities

  20. Proceedings of the NEA Clay Club Workshop on Clay characterisation from nanoscopic to microscopic resolution

    International Nuclear Information System (INIS)

    2013-01-01

    A wide spectrum of argillaceous media are being considered in Nuclear Energy Agency (NEA) member countries as potential host rocks for the final, safe disposal of radioactive waste, and/or as major constituent of repository systems in which wastes will be emplaced. In this context, the NEA established the Working Group on the 'Characterisation, the Understanding and the Performance of Argillaceous Rocks as Repository Host Formations' in 1990, informally known as the 'Clay Club'. The Clay Club examines various argillaceous rocks that are being considered for the underground disposal of radioactive waste, ranging from soft clays to indurated shales. Very generally speaking, these clay rocks are composed of fine-grained minerals showing pore sizes from < 2 nm (micropores) up to > 50 nm (macro-pores). The water flow, solute transport and mechanical properties are largely determined by this microstructure, the spatial arrangement of the minerals and the chemical pore water composition. Examples include anion accessible ('geochemical') porosity and macroscopic membrane effects (chemical osmosis, hyper-filtration), geomechanical properties and the characteristics of two-phase flow properties (relevant for gas transport). At the current level of knowledge, there is a strong need to improve the nanoscale description of the phenomena observed at a more macroscopic scale. However, based on the scale of individual clay-minerals and pore sizes, for most of the imaging techniques this resolution is a clear challenge. The workshop, hosted by the Institute for Nuclear Waste Disposal (INE), Karlsruhe Institute of Technology (KIT) in the Akademiehotel Karlsruhe (Germany) from 6 to 8 September 2011, was intended to give, inter alia, a discussion platform on: - The current state-of-the-art of different spectro-microscopic methods - New developments addressing the above mentioned knowledge gaps in clays. - The perception of the interplay between geometry

  1. Current results of an arachnological survey of some sandstone rock sites in Bohemia (so-called "rock cities"

    Directory of Open Access Journals (Sweden)

    Růžička, Vlastimil

    1992-07-01

    Full Text Available The spider fauna of the Adrspach-Teplice rockswas investigated. Some records on spider fauna of other nine sandstone rock areas are included. The phenomenon of "rock cities" manifests itself in three aspects: (1 In the bottom parts are microclimatically cold spaces, frequently hosting northern ot mountain species of invertebrates, which here have an azonal occurence. (2 the sun exposed tops of rocks can host thermophilous species. (3 Some species are limited to the surface of rocks and boulders. These are referred to as lithophilous or lithobiont species.

  2. Factor analysis of geochemical data from ore and host rocks of the uranium mineralization at Mika, N. E. Nigeria

    International Nuclear Information System (INIS)

    Funtua, I. I.

    1997-01-01

    The Mika uranium occurrence is located in one of a series of NW-NE trending shear zones which host uraniferous Jurassic rhyolitic dykes located in Pan-African brecciated granites within peraluminous granite complex of NE Nigeria. The bodies of mineralization are about 100 metres long and up to 4 metres thick. The U mineralization associated with the rhyolite dykes contains predominantly meta-autunite and apatite, while that of the brecciated granites displays variable mineralogy with meta-autunite, one or two generations of coffinite and colloformic, pitch blend in open veins. The mineralization is thought to be related to bimodel magmatism of the Burashika group and the reactivation of regional structures. Multivariate statistical evaluation of geochemical data of 28 elements/oxides in 296 host rock and mineralized samples from the surface and drill cores display a coherent association of [(U, Pb, Zn, Cu, P 2 O 5 , Fe 2 O 3 ) + Mo], [(CaO, Zr, Sr) +(Y, Mo, V, As)] and [(MgO, K 2 O) + (TiO 2 , Rb)] in the mineralized rocks; reflecting the presence of hamatized phosphate bearing ores in association with sulphide minerals and apatite in the granite rhyolites. A link of the mineralizing fluids with the emplacement of the rhyolites is implied from the striking resemblance between the above element association in mineralized rocks to those of the unmineralized rhyolites. A source of ore fluids over saturated in uranium and silica emanating from crystallizing rhyolitic melts which were expelled into faults and/or shear zones in the surrounding country rock is inferred

  3. Science design for two shafts in phase 1a of the proposed rock characterisation facility at Sellafield, UK

    International Nuclear Information System (INIS)

    Ledingham, P.; Proughten, A.J.; Saulnier, G.J. Jr.

    1998-01-01

    In 1997, United Kingdom Nirex planned to begin construction of an underground Rock Characterisation Facility (RCF) at Sellafield as part of it's ongoing assessment of the suitability of the site as a host for a deep radioactive waste repository. The RCF was to have addressed issues relating to the geology, hydrogeology and geomechanical behaviour of the site by collecting data for testing predictive models and acquiring information only available from an underground situation. In March 1997, the UK Government refused permission for Nirex to begin construction and work at Sellafield was wound down. However, the science design for Phase 1a of the RCF, two vertical access shafts, was completed to provide a set of conceptual designs which address the issues identified by Nirex. By using Sellafield as an example, the designs contribute to a series of reports which demonstrate an approach to validation using an underground facility. This paper describes the Science Design for data collection during shaft construction, which began with the information requirements specified by Nirex on the basis of it's conceptual models and predictive work. It describes the scientific measurements designed to acquire this information and the process of combining the individual measurements into test plans for each shaft. Measurements were planned in the shafts themselves and in boreholes drilled from the shafts. They were designed to provide data on formation porosity and permeability, the geochemistry of formation water and the nature of the fresh-water salt-water interface, shaft inflow, the influence of geological structures on performance, and geomechanical responses to shaft excavation. A key element of the design process was the development of test plans, requiring the co-ordination and integration of the construction and science activities so that both could be carried out in a timely and cost-effective manner

  4. Characterisation of cell death inducing Phytophthora capsici CRN effectors suggests diverse activities in the host nucleus

    Directory of Open Access Journals (Sweden)

    Remco eStam

    2013-10-01

    Full Text Available Plant-Microbe interactions are complex associations that feature recognition of Pathogen Associated Molecular Patterns by the plant immune system and dampening of subsequent responses by pathogen encoded secreted effectors. With large effector repertoires now identified in a range of sequenced microbial genomes, much attention centres on understanding their roles in immunity or disease. These studies not only allow identification of pathogen virulence factors and strategies, they also provide an important molecular toolset suited for studying immunity in plants. The Phytophthora intracellular effector repertoire encodes a large class of proteins that translocate into host cells and exclusively target the host nucleus. Recent functional studies have implicated the CRN protein family as an important class of diverse effectors that target distinct subnuclear compartments and modify host cell signalling. Here, we characterised three necrosis inducing CRNs and show that there are differences in the levels of cell death. We show that only expression of CRN20_624 has an additive effect on PAMP induced cell death but not AVR3a induced ETI. Given their distinctive phenotypes, we assessed localisation of each CRN with a set of nuclear markers and found clear differences in CRN subnuclear distribution patterns. These assays also revealed that expression of CRN83_152 leads to a distinct change in nuclear chromatin organisation, suggesting a distinct series of events that leads to cell death upon over-expression. Taken together, our results suggest diverse functions carried by CRN C-termini, which can be exploited to identify novel processes that take place in the host nucleus and are required for immunity or susceptibility.

  5. Rock critics as 'Mouldy Modernists'

    Directory of Open Access Journals (Sweden)

    Becky Shepherd

    2011-08-01

    Full Text Available Contemporary rock criticism appears to be firmly tied to the past. The specialist music press valorise rock music of the 1960s and 1970s, and new emerging artists are championed for their ‘retro’ sounding music by journalists who compare the sound of these new artists with those included in the established ‘canon’ of rock music. This article examines the narrative tropes of authenticity and nostalgia that frame the retrospective focus of this contemporary rock writing, and most significantly, the maintenance of the rock canon within contemporary popular culture. The article concludes by suggesting that while contemporary rock criticism is predominately characterised by nostalgia, this nostalgia is not simply a passive romanticism of the past. Rather, this nostalgia fuels a process of active recontextualisation within contemporary popular culture.

  6. The TIMODAZ project: Thermal impact on the damaged zone around a radioactive waste disposal in clay host rocks

    International Nuclear Information System (INIS)

    XiangLing, L.

    2009-01-01

    The management of spent nuclear fuel and other long-lived radio active waste is an important environmental issue today. Disposal in deep clay geological formations is one of the promising options to dispose of these wastes. In this context, the related research activities in the Euratom Framework Programme of European Commission are continually taking on an enhanced significance. The TIMODAZ is one of the STREP projects (Specific Targeted Research Project) in the Sixth EURATOM Framework Programme and contributes to the research related to the geological disposal of radioactive waste. The consortium is composed of a strong multidisciplinary team involving both European radioactive waste management organizations and nuclear research institutes, universities, industrial partners as well as consultancy companies (SME's). Totally, 15 partners coming from 8 countries are involved with a total budget of about 4000k EURO. Being the coordinator (through the EURIDICE expertise group), SCK-CEN plays the leading role in the project. Meanwhile, SCK-CEN participates the research in different work packages covering the laboratory tests, in-situ tests as well as the integration of TIMODAZ results within the safety case. An important item for the long-term safety of underground disposal is the proper evaluation of the DZ (damaged zone) in the clay host rock. The DZ is defined here as the zone of host rock that experiences THMC (Thermo-Hydro-Mechanical-Chemical) modifications induced by the repository, with potential major changes in the transport properties for radionuclides. The DZ is first initiated during the repository construction. Its behaviour is dynamic, dependent on changing conditions that vary from the open-drift period, to initial closure period and to the entire heating-cooling cycle of the decaying waste. The early THMC disturbances created by the excavation, the operational phase and the thermal load might be the most severe transient that the repository will undergo

  7. Subsurface geology, geochemistry, and water flow at a Rock Characterisation Facility (RCF) at Longlands Farm. Proof of evidence

    International Nuclear Information System (INIS)

    Haszeldine, R.S.

    1996-01-01

    Proof of Evidence is given by an expert witness on behalf of Greenpeace Ltd as part of their submission to a Planning Inquiry in 1995 hearing the application of UK Nirex Ltd for permission to construct an underground Rock Characterisation Facility (RCF) at a site near Sellafield. The RCF is part of an investigation by Nirex into a suitable site for the disposal of radioactive waste. The evidence covers: a description of the general physical geology of the site; the contrast between Nirex's approach to this site investigation and those of hydrocarbon exploration; the possibility of tectonic movements in the region which are likely to affect subsurface water flows within the repository lifetime and could produce additional permeable water flow pathways through the RCF; an interpretation of Nirex data which indicates that the RCF site is on an axis of maximum flow in the subsurface; regional permeability between boreholes in the underlying fractured rock; recharge of subsurface waters during glaciation; doubts about the age-dating of subsurface water; the complex and sensitive hydrogeological setting of the site in which water flow directions are upwards and could be rapid; expert dissent relating to Nirex's assessment of regional geochemical processes affecting radionuclide release; disagreement in Nirex's assessment of the present groundwater chemistry which may influence the durability of a repository. The construction of the RCF could actually impede the resolution of some of these issues and it is concluded that, although the principle of a rock laboratory might be supported, the Nirex approach is fundamentally flawed. (18 figures; 20 references). (UK)

  8. Physical Matrix Characterisation: Studies of Crystalline Rocks and Consolidated Clays by PMMA Method and Electron Microscopy as a Support of Diffusion Analyses

    International Nuclear Information System (INIS)

    Siitari-Kauppi, M.; Leskinen, A.; Kelokaski, A.; Togneri, L.; Alonso, U.; Missana, T.; Garcia-Gutierrez, M.; Patelli, A.

    2007-01-01

    Crystalline rock and consolidated clay are both considered adequate host rocks for a high-level radioactive waste deep geological repository (HLWR). Over the extended periods of HLWR operation, long-lived radionuclides (RN) may be released from the fuel and migrate to the geo/biosphere. To predict the fate of contaminants and to assess the safety of the host rock, it is very important to determine transport parameters, as diffusion coefficients, and to relate them to the physical properties of the barriers, as connected porosity. In heterogeneous materials, it is also a major task to describe the transport at the mineral scale evaluating diffusion coefficients and mineral-specific porosities on single minerals. The main objective of this study was to determine within granite and consolidated clay, the connective porosity and mineral-specific porosities by poly-methylmethacrylate (PMMA) autoradiography method. Scanning electron microscopy and energy-dispersive X-ray analyses (FESEM/EDS) were performed in order to study the pore apertures of porous regions in greater detail and to identify the corresponding minerals. By the novel application of the nuclear ion beam technique Rutherford Backscattering Spectrometry (RBS) apparent diffusion coefficients were determined at mineral scale. Finally, the porosity results were used to evaluate the effective diffusion coefficients and retention parameters of single minerals in different granite samples and consolidated clays. (Author) 42 refs

  9. CLOSE RANGE HYPERSPECTRAL IMAGING INTEGRATED WITH TERRESTRIAL LIDAR SCANNING APPLIED TO ROCK CHARACTERISATION AT CENTIMETRE SCALE

    Directory of Open Access Journals (Sweden)

    T. H. Kurz

    2012-07-01

    Full Text Available Compact and lightweight hyperspectral imagers allow the application of close range hyperspectral imaging with a ground based scanning setup for geological fieldwork. Using such a scanning setup, steep cliff sections and quarry walls can be scanned with a more appropriate viewing direction and a higher image resolution than from airborne and spaceborne platforms. Integration of the hyperspectral imagery with terrestrial lidar scanning provides the hyperspectral information in a georeferenced framework and enables measurement at centimetre scale. In this paper, three geological case studies are used to demonstrate the potential of this method for rock characterisation. Two case studies are applied to carbonate quarries where mapping of different limestone and dolomite types was required, as well as measurements of faults and layer thicknesses from inaccessible parts of the quarries. The third case study demonstrates the method using artificial lighting, applied in a subsurface scanning scenario where solar radiation cannot be utilised.

  10. Modeling gas migration experiments in repository host rocks for the MEGAS project

    International Nuclear Information System (INIS)

    Worgan, K.; Impey, M.; Volckaert, G.; DePreter, P.

    1993-01-01

    In response to concerns over the possibility of hydrogen gas generation within an underground repository for high-level radioactive waste, and its implications for repository safety, a joint European research study (MEGAS) is underway. Its aims are to understand and characterize the behavior of gas migration within an argillacious, host-rock. Laboratory experiments are being carried out by SCK/CEN, BGS and ISMES. SCK/CEN are also conducting in situ experiments at the underground laboratory at Mol, Belgium. Modeling of gas migration is being done in parallel with the experiments, by Intera Information Technologies. A two-phase flow code, TOPAZ, has been developed specifically for this work. In this paper the authors report on the results of some preliminary calculations performed with TOPAZ, in advance of the in situ experiments

  11. Reactive transport simulations of the evolution of a cementitious repository in clay-rich host rocks

    Science.gov (United States)

    Kosakowski, Georg; Berner, Urs; Kulik, Dmitrii A.

    2010-05-01

    that the clay mineral is represented by a X- '(solute) ligand' initially occupied with e.g. Na+. Our representation of cation exchange is based on a multi end-member ideal solid solution model for the clay which at the same time considers the chemical reactivity of the clay phase in the high pH cement environment. As a first application, we will present the results of calculations of the interaction between a cement compartment in contact with a clay-rich host rock. References: Bradbury, M. & Baeyens, B. (2002). Porewater chemistry in compacted re-saturated MX-80 bentonite: Physico-chemical characterisation and geochemical modelling. PSI-Report 02-10, Paul Scherrer Institut, Villigen, Switzerland. Lothenbach, B. & Wieland, E. (2006). A thermodynamic approach to the hydration of sulphate-resisting Portland cement. Waste Management, 26, 706-719. Shao, H., Dmytrieva, S.V., Kolditz, O., Kulik, D.A., Pfingsten, W. & Kosakowski, G. (2009). Modeling reactive transport in non-ideal aqueous-solid solution system. Applied Geochemistry, 24(7), 1287-1300.

  12. The Metamorphic Rocks-Hosted Gold Mineralization At Rumbia Mountains Prospect Area In The Southeastern Arm of Sulawesi Island, Indonesia

    Directory of Open Access Journals (Sweden)

    Hasria Hasria

    2017-09-01

    Full Text Available Recently, in Indonesia gold exploration activities  are not only focused along volcanic-magmatic belts, but also starting to shift along metamorphic and sedimentary terrains. The study area is located in Rumbia mountains, Bombana Regency, Southeast Sulawesi Province. This paper is aimed to describe characteristics of alteration and ore mineralization associated  with metamorphic rock-related gold deposits.  The study area is found the placer and  primary gold hosted by metamorphic rocks. The gold is evidently derived from gold-bearing quartz veins hosted by Pompangeo Metamorphic Complex (PMC. These quartz veins are currently recognized in metamorphic rocks at Rumbia Mountains. The quartz veins are mostly sheared/deformed, brecciated, irregular vein, segmented and  relatively massive and crystalline texture with thickness from 1 cm to 15.7 cm. The wallrock are generally weakly altered. Hydrothermal alteration types include sericitization, argillic, inner propylitic, propylitic, carbonization and carbonatization. There some precious metal identified consist of native gold and ore mineralization including pyrite (FeS2, chalcopyrite (CuFeS2, hematite (Fe2O3, cinnabar (HgS, stibnite (Sb2S3 and goethite (FeHO2. The veins contain erratic gold in various grades from below detection limit <0.0002 ppm to 18.4 ppm. Based on those characteristics, it obviously indicates that the primary gold deposit present in the study area is of orogenic gold deposit type. The orogenic gold deposit is one of the new targets for exploration in Indonesia

  13. Life in a rock pool: Radiation and population genetics of myxozoan parasites in hosts inhabiting restricted spaces.

    Science.gov (United States)

    Bartošová-Sojková, Pavla; Lövy, Alena; Reed, Cecile C; Lisnerová, Martina; Tomková, Tereza; Holzer, Astrid S; Fiala, Ivan

    2018-01-01

    Intertidal rock pools where fish and invertebrates are in constant close contact due to limited space and water level fluctuations represent ideal conditions to promote life cycles in parasites using these two alternate hosts and to study speciation processes that could contribute to understanding the roles of parasitic species in such ecosystems. Gall bladder and liver samples from five clinid fish species (Blenniiformes: Clinidae) were morphologically and molecularly examined to determine the diversity, prevalence, distribution and host specificity of Ceratomyxa parasites (Cnidaria: Myxozoa) in intertidal habitats along the coast of South Africa. Phylogenetic relationships of clinid ceratomyxids based on the SSU rDNA, LSU rDNA and ITS regions were assessed additionally to the investigation of population genetic structure of Ceratomyxa cottoidii and subsequent comparison with the data known from type fish host Clinus cottoides. Seven Ceratomyxa species including previously described Ceratomyxa dehoopi and C. cottoidii were recognized in clinids. They represent a diverse group of rapidly evolving, closely related species with a remarkably high prevalence in their hosts, little host specificity and frequent concurrent infections, most probably as a result of parasite radiation after multiple speciation events triggered by limited host dispersal within restricted spaces. C. cottoidii represents the most common clinid parasite with a population structure characterized by young expanding populations in the south west and south east coast and by older populations in equilibrium on the west coast of its distribution. Parasite and fish host population structures show overlapping patterns and are very likely affected by similar oceanographic barriers possibly due to reduced host dispersal enhancing parasite community differentiation. While fish host specificity had little impact on parasite population structure, the habitat preference of the alternate invertebrate host as

  14. Characterisation and modelling of mixing processes in groundwaters of a potential geological repository for nuclear wastes in crystalline rocks of Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Gómez, Javier B., E-mail: jgomez@unizar.es; Gimeno, María J., E-mail: mjgimeno@unizar.es; Auqué, Luis F., E-mail: lauque@unizar.es; Acero, Patricia, E-mail: patriace@unizar.es

    2014-01-01

    This paper presents the mixing modelling results for the hydrogeochemical characterisation of groundwaters in the Laxemar area (Sweden). This area is one of the two sites that have been investigated, under the financial patronage of the Swedish Nuclear Waste and Management Co. (SKB), as possible candidates for hosting the proposed repository for the long-term storage of spent nuclear fuel. The classical geochemical modelling, interpreted in the light of the palaeohydrogeological history of the system, has shown that the driving process in the geochemical evolution of this groundwater system is the mixing between four end-member waters: a deep and old saline water, a glacial meltwater, an old marine water, and a meteoric water. In this paper we put the focus on mixing and its effects on the final chemical composition of the groundwaters using a comprehensive methodology that combines principal component analysis with mass balance calculations. This methodology allows us to test several combinations of end member waters and several combinations of compositional variables in order to find optimal solutions in terms of mixing proportions. We have applied this methodology to a dataset of 287 groundwater samples from the Laxemar area collected and analysed by SKB. The best model found uses four conservative elements (Cl, Br, oxygen-18 and deuterium), and computes mixing proportions with respect to three end member waters (saline, glacial and meteoric). Once the first order effect of mixing has been taken into account, water–rock interaction can be used to explain the remaining variability. In this way, the chemistry of each water sample can be obtained by using the mixing proportions for the conservative elements, only affected by mixing, or combining the mixing proportions and the chemical reactions for the non-conservative elements in the system, establishing the basis for predictive calculations. - Highlights: • Laxemar (Sweden) groundwater is the combined result

  15. Characterisation and modelling of mixing processes in groundwaters of a potential geological repository for nuclear wastes in crystalline rocks of Sweden

    International Nuclear Information System (INIS)

    Gómez, Javier B.; Gimeno, María J.; Auqué, Luis F.; Acero, Patricia

    2014-01-01

    This paper presents the mixing modelling results for the hydrogeochemical characterisation of groundwaters in the Laxemar area (Sweden). This area is one of the two sites that have been investigated, under the financial patronage of the Swedish Nuclear Waste and Management Co. (SKB), as possible candidates for hosting the proposed repository for the long-term storage of spent nuclear fuel. The classical geochemical modelling, interpreted in the light of the palaeohydrogeological history of the system, has shown that the driving process in the geochemical evolution of this groundwater system is the mixing between four end-member waters: a deep and old saline water, a glacial meltwater, an old marine water, and a meteoric water. In this paper we put the focus on mixing and its effects on the final chemical composition of the groundwaters using a comprehensive methodology that combines principal component analysis with mass balance calculations. This methodology allows us to test several combinations of end member waters and several combinations of compositional variables in order to find optimal solutions in terms of mixing proportions. We have applied this methodology to a dataset of 287 groundwater samples from the Laxemar area collected and analysed by SKB. The best model found uses four conservative elements (Cl, Br, oxygen-18 and deuterium), and computes mixing proportions with respect to three end member waters (saline, glacial and meteoric). Once the first order effect of mixing has been taken into account, water–rock interaction can be used to explain the remaining variability. In this way, the chemistry of each water sample can be obtained by using the mixing proportions for the conservative elements, only affected by mixing, or combining the mixing proportions and the chemical reactions for the non-conservative elements in the system, establishing the basis for predictive calculations. - Highlights: • Laxemar (Sweden) groundwater is the combined result

  16. Ground deformation at collapse calderas: influence of host rock lithology and reservoir multiplicity

    Energy Technology Data Exchange (ETDEWEB)

    Geyer, A; Gottsmann, J [Department of Earth Sciences, University of Bristol, Wills Memorial Building, Queen' s Road, BS8 1RJ, Bristol (United Kingdom)], E-mail: A.GeverTraver@bristol.ac.uk

    2008-10-01

    A variety of source mechanisms have been proposed to account for observed caldera deformation. Here we present a systematic set of new results from numerical forward modelling using a Finite Element Method. which provides a link between measured ground deformation and the inaccessible deformation source. We simulate surface displacements due to pressure changes in a shallow oblate reservoir overlain by host rock with variable mechanical properties. We find that the amplitude and wavelength of resultant ground deformation is dependent on the distribution of mechanically stiff and soft lithologies and their relative distribution above a reservoir. In addition, we note an influence of layering on the critical ratio of horizontal over vertical displacements, a criterion employed to discriminate between different finite source geometries.

  17. Uncertainty in hydraulic tests in fractured rock

    International Nuclear Information System (INIS)

    Ji, Sung-Hoon; Koh, Yong-Kwon

    2014-01-01

    Interpretation of hydraulic tests in fractured rock has uncertainty because of the different hydraulic properties of a fractured rock to a porous medium. In this study, we reviewed several interesting phenomena which show uncertainty in a hydraulic test at a fractured rock and discussed their origins and the how they should be considered during site characterisation. Our results show that the estimated hydraulic parameters of a fractured rock from a hydraulic test are associated with uncertainty due to the changed aperture and non-linear groundwater flow during the test. Although the magnitude of these two uncertainties is site-dependent, the results suggest that it is recommended to conduct a hydraulic test with a little disturbance from the natural groundwater flow to consider their uncertainty. Other effects reported from laboratory and numerical experiments such as the trapping zone effect (Boutt, 2006) and the slip condition effect (Lee, 2014) can also introduce uncertainty to a hydraulic test, which should be evaluated in a field test. It is necessary to consider the way how to evaluate the uncertainty in the hydraulic property during the site characterisation and how to apply it to the safety assessment of a subsurface repository. (authors)

  18. Heterogeneity of uranium host rocks in Zhiluo formation in Dongsheng area and its relation to uranium mineralization

    International Nuclear Information System (INIS)

    Yi Chao; Zheng Yunlong; Wang Mingtai

    2013-01-01

    Numbers of uranium deposits have be found in Dongsheng area. The major ore-bearing layer is the sub member of the lower member of the Zhiluo Formation, the heterogeneity of host rocks plays an important role during the process of uranium mineralization. This paper sorted and counted up the data of sand body and the impermeable bed in Dongsheng area to study the heterogeneity characteristic of host rock and its relationship to uranium mineralization in horizontal and vertical directions. The thickness of sand body in Dongsheng area decreases gradually from northwest to southeast. The uranium mineralization is mainly distributed in the place where the thickness of sand body changed from the thick to the thin. Statistics shows that the best uranium mineralization occurred in sand body thickness between 20 m to 40 m and the sand rate over 60% in the eastern part of Dongsheng area. And the best uranium mineralization in the western part occurred in area of sand body thickness between 60 m to 70 m and the sand rate over 70%. In vertical direction, the numbers and the thickness of the impermeable beds have negative relation to sand rate. Moreover, uranium deposits generally exist in the area of less number impermeable bed and small thickness. The uranium mineralization grade decreased with the increase of number and thickness of the impermeable beds. (authors)

  19. Geochronology of the Swift Current granite and host volcanic rocks of the Love Cove group, southwestern Avalon zone, Newfoundland

    International Nuclear Information System (INIS)

    Dallmeyer, R.D.; O'Driscoll, C.F.; Hussey, E.M.

    1981-01-01

    Zircon fractions from the variably deformed and metamorphosed Swift Current granite and host volcanic rocks of the Love Cove Group record individually discordant U-Pb ages with well-defined upper concordia intercept ages of 580 +- 20 and 590 +- 30 Ma, respectively. These are interpreted to be crystallization dates and indicate a late Proterozoic cogmagmatic relationship. Primary hornblende from the pluton record disturbed 40 Ar/ 39 Ar age spectra that suggest postcrystallization argon loss, probably during Acadian (Devonian) regional metamorphism. 40 Ar/ 39 Ar plateau ages of 560-566 Ma are well defined for the hornblende and are interpreted to date times of postmagmatic cooling. The similarity between zircon and hornblende dates suggests relatively rapid postmagmatic cooling. A six-point, Rb-Sr whole-rock isochron age of 548 +- 11 Ma is defined for the pluton. The slight discordancy of this date in comparison with the zircon and hornblende ages may reflect a minor disturbance of whole-rock isotopic systems during Acadian regional metamorphism. (author)

  20. Grimsel test site. Investigation phase VI. Pore space geometry project. Characterisation of pore space geometry by 14C-MMA impregnation

    International Nuclear Information System (INIS)

    Kelokaski, M.; Siitari-Kauppi, M.; Kauppi, I.; Hellmuth, K.-H.; Moeri, A.; Inderbitzin, L.; Biggin, C.; Kickmaier, W.; Martin, A.

    2010-04-01

    In Finland high-level radioactive waste is planned to be disposed of in a deep geological repository within a crystalline host rock. The potential role of the geosphere as a safety barrier in repository performance assessment is well established. However, uncertainties in both transport pathway definition and pore space characterisation of crystalline rock still exist and the repository safety evaluation today requires going from laboratory and surface-based field work to the underground repository level. Little is known about the changes to rock transport properties during sampling and decompression. Recent investigations using resin impregnation of the rock matrix at the Grimsel Test Site imply that non-conservative errors in calculated transport properties derived from laboratory data may reach factors of two to three. Due to the potentially great significance of pore space characterisation to safety analysis calculations, it was decided to study the rock matrix characteristics in situ using methylmethacrylate (MMA) resin labelled with 14 C. During the last decade, the poly-methylmethacrylate (PMMA) method has been developed for characterising the porosity of low permeable granitic rocks in the laboratory. Impregnation with 14 C-labelled methylmethacrylate ( 14 C-MMA) and autoradiography allows investigation of the spatial distribution of accessible porosity at the centimetre scale. Quantitative measurements of total or mineral-specific local porosities have been obtained using image analysis tools. Electron microscopy examinations and mercury porosimetry measurements have provided detailed information on pore and fissure apertures. The objective of this work was to develop an in situ application of the PMMA impregnation technique. The changes in rock porosity due to stress relaxation when overcoring the samples from the bedrock for the laboratory studies were examined. The concept behind the work was to inject 14 C-MMA from a central borehole at a depth of

  1. Characterisation and genesis of the Singhbhum uranium province, India

    International Nuclear Information System (INIS)

    Mahadevan, T.M.

    1988-01-01

    The Singhbhum Uranium province is characterised by the late Archaean predominantly granitic Singhbhum Craton and the associated Proterozoic mobile belts, the boundaries of which are marked by major crustal dislocations. The Singhbhum craton had two-phase evolution during the time range 4000-2900 million years and its stabilisation around 2900 million years was marked by the emplacement of K-rich granitoids and the early crustal enrichment of uranium. Two distinctive types of uranium mineralisation occur in the Province - (i) the early Quartz Pebble Conglomerate (QPC) type and (ii) the later economically most significant shear-controlled hydrothermal type. The QPC type is confined to the cratonic volcano-sedimentary basins, characterised by basal fluvial high-energy deposits, near-continental volcanics and banded iron formations spanning the time band of 2900-2500 million years. The shear controlled hydrothermal mineralisation is predominantly developed in a 200 km-long arcuate zone of intense and deep tectonisation, acid-(?) alkaline-basic magmatism, hydrothermal activity and metallogenesis. This shear zone represents a belt of intense crust-mantle interaction. Uranium mineralisation is polyphasic, polymetallic. The mineralogy is complex and the chemistry of the ores is greatly influenced by the lithology of the host rocks involved in the shear. Part of the shear zone grazing the Dhanjori, predominantly volcanic supra-crustals is richer in U, Cu, Ni, Mo and also contains minor Bi, Au, Ag, Te and Se, while the western trans-Dhanjori sector of the shear zone characterised by schists and quartzites with lesser volcanic component is relatively poorer in these metals. The ore bodies in the trans-Dhanjori sector are more peneconcordant, gradational, stratabound and have spherical variograms, while those in the Dhanjori sector are transgressive, sharp, highly mobilised, vein type with Dewijsian variograms. A synthesis leads to the conclusion that uranium mineralisation is

  2. Clay shale as host rock. A geomechanical contribution about Opalinus clay; Tonstein als Wirtsgestein. Ein geomechanischer Beitrag ueber Opalinuston

    Energy Technology Data Exchange (ETDEWEB)

    Lempp, Christof; Menezes, Flora; Sachwitz, Simon [Halle-Wittenberg Univ., Halle (Saale) (Germany). Inst. fuer Geowissenschaften und Geographie

    2016-12-15

    The Opalinuston is a prominent rock representing the type of organic clay shales or clay stones within the sequence of Triassic and Jurassic marine sediments in Southern Germany. The rock forms a homogenous unit some ten meters thick. The degree of consolidation of this type of pelitic rock depends mainly on the former load conditions, but is also dependent on the long-term weathering and even on the present exposition. The geomechanical parameters such as shear strength, tensional strength and permeability vary with the state of consolidation and become important when the use is discussed of such rocks for radioactive waste disposal. A tunneling project at the northern escarpment of the Swabian Alb (Southwest Germany) within the Opalinus clay offered the rare opportunity to obtain fresh unweathered rock samples in greater amounts compared to fresh drilling cores from which geomechanical investigations are usually undertaken. Consequently, the results of geomechanical laboratory testings are presented in order to compare here the results of multistep triaxial compression tests, of hydraulic fracturing laboratory tests and of some other tests for rock characterization with the corresponding results of Opalinus clay sites in Switzerland that were investigated by the Swiss Nagra Company for host rock characterization. After a discussion of the relevant state of fresh Opalinus clay, especially of suction pressure conditions and saturation state, the results of triaxial shear tests are presented. Increasing shear deformation at increasing pressure and unchanged water saturation do not result in a significant strength reduction of the Opalinus clay. The rock shows increasing cohesion and stiffness, if multiple loading has repeatedly reached the failure point. Thus there is no increased permeability with continued shearing. Only at the beginning of the shearing process is a temporarily increased permeability to be expected due to dilatation processes. An increased

  3. On thermal properties of hard rocks as a host environment of an underground thermal energy storage

    Science.gov (United States)

    Novakova, L.; Hladky, R.; Broz, M.; Novak, P.; Lachman, V.; Sosna, K.; Zaruba, J.; Metelkova, Z.; Najser, J.

    2013-12-01

    With increasing focus on environmentally friendly technologies waste heat recycling became an important issue. Under certain circumstances subsurface environment could be utilized to accommodate relatively large quantity of heat. Industrial waste heat produced during warm months can be stored in an underground thermal energy storage (UTES) and used when needed. It is however a complex task to set up a sustainable UTES for industrial scale. Number of parameters has to be studied and evaluated by means of thermohydromechanical and chemical coupling (THMC) before any UTES construction. Thermal characteristics of various rocks and its stability under thermal loading are amongst the most essential. In the Czech Republic study two complementary projects THMC processes during an UTES operation. The RESEN project (www.resen.cz) employs laboratory tests and experiments to characterise thermal properties of hard rocks in the Bohemian Massif. Aim of the project is to point out the most suitable rock environment in the Bohemian Massif for moderate to ultra-high temperature UTES construction (Sanyal, 2005). The VITA project (www.geology.cz/mokrsko) studies THM coupling in non-electrical temperature UTES using long term in-situ experiment. In both projects thermal properties of rocks were studied. Thermal conductivity and capacity were measured on rock samples. In addition an influence of increasing temperature and moisture content was considered. Ten hard rocks were investigated. The set included two sandstones, two ignibrites, a melaphyr, a syenite, two granites, a gneiss and a serpentinite. For each rock there were measured thermal conductivity and capacity of at least 54 dried samples. Subsequently, the samples were heated up to 380°C in 8 hours and left to cool down. Thermal characteristics were measured during the heating period and after the sample reached room temperature. Heating and cooling cycle was repeated 7 to 10 times to evaluate possible UTES-like degradation of

  4. THM-coupled modeling of selected processes in argillaceous rock relevant to rock mechanics; THM-Gekoppelte Modellierung ausgewaehlter gesteinsmechanisch relevanter Prozesse im Tongestein

    Energy Technology Data Exchange (ETDEWEB)

    Czaikowski, Oliver [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Braunschweig (Germany). Repository Safety Research Div.

    2012-08-15

    Scientific investigations in European countries other than Germany concentrate not only on granite formations (Switzerland, Sweden) but also on argillaceous rock formations (France, Switzerland, Belgium) to assess their suitability as host and barrier rock for the final storage of radioactive waste. In Germany, rock salt has been under thorough study as a host rock over the past few decades. According to a study by the German Federal Institute for Geosciences and Natural Resources, however, not only salt deposits but also argillaceous rock deposits are available at relevant depths and of extensions in space which make final storage of high-level radioactive waste basically possible in Germany. Equally qualified findings about the suitability/unsuitability of non-saline rock formations require fundamental studies to be conducted nationally because of the comparatively low level of knowledge. The article presents basic analyses of coupled mechanical and hydraulic properties of argillaceous rock formations as host rock for a repository. The interaction of various processes is explained on the basis of knowledge derived from laboratory studies, and open problems are deduced. For modeling coupled processes, a simplified analytical computation method is proposed and compared with the results of numerical simulations, and the limits to its application are outlined. (orig.)

  5. Fault Rock Zones Characterisation - Final report. TRUE-1 Continuation Project

    International Nuclear Information System (INIS)

    Winberg, Anders

    2010-11-01

    At the conclusion of the TRUE-1 and TRUE Block Scale experimental programmes at the Aespoe Hard Rock Laboratory one remaining identified uncertainty was the in situ internal structure of conductive structures, and in particular the in situ material properties of unconsolidated fault gouge of such conductive structures. With the aim of reducing these uncertainties an experimental program has been conducted at depth in the Aespoe Hard Rock Laboratory. Four conductive structures in the immediate vicinity of the Aespoe tunnel were identified for further study. Following basic geometrical and geological modelling based on tunnel observations, geological/ mineralogical and hydrogeological investigations in four boreholes at each site, epoxy resin was injected in selected packed off borehole sections containing the structure. Following a sufficient time for curing of the epoxy, the injected borehole 72 mm sections were overcored with a 300 mm core barrel. Customised techniques were employed to section the core in the borehole and for its retrieval out of the borehole. Following basic geological mapping, selected overcores were sectioned and were subject to image analysis to assess the pore structure using a variety of different descriptive geometrical attributes. In addition, an attempt was made to infer the porosity of the fault rock (including fault gouge) using binary images. Since analysis has been made on multiple slices of impregnated rock it is also possible to crudely map the 3D variability of a given entity. It was furthermore identified that porosity estimates, which range from some 10-70% are, apart from being dependent on the penetration of the epoxy, dependent on the resolution of the given image, the size of the averaging window, and the porosity components contained therein. The obtained quantifications of porosity can therefore only be regarded as ball-park relative porosities of a complete fault rock zones. It does not, however, provide firm

  6. Fault Rock Zones Characterisation - Final report. TRUE-1 Continuation Project

    Energy Technology Data Exchange (ETDEWEB)

    Winberg, Anders (ed.) (Conterra AB (Sweden))

    2010-11-15

    At the conclusion of the TRUE-1 and TRUE Block Scale experimental programmes at the Aespoe Hard Rock Laboratory one remaining identified uncertainty was the in situ internal structure of conductive structures, and in particular the in situ material properties of unconsolidated fault gouge of such conductive structures. With the aim of reducing these uncertainties an experimental program has been conducted at depth in the Aespoe Hard Rock Laboratory. Four conductive structures in the immediate vicinity of the Aespoe tunnel were identified for further study. Following basic geometrical and geological modelling based on tunnel observations, geological/ mineralogical and hydrogeological investigations in four boreholes at each site, epoxy resin was injected in selected packed off borehole sections containing the structure. Following a sufficient time for curing of the epoxy, the injected borehole 72 mm sections were overcored with a 300 mm core barrel. Customised techniques were employed to section the core in the borehole and for its retrieval out of the borehole. Following basic geological mapping, selected overcores were sectioned and were subject to image analysis to assess the pore structure using a variety of different descriptive geometrical attributes. In addition, an attempt was made to infer the porosity of the fault rock (including fault gouge) using binary images. Since analysis has been made on multiple slices of impregnated rock it is also possible to crudely map the 3D variability of a given entity. It was furthermore identified that porosity estimates, which range from some 10-70% are, apart from being dependent on the penetration of the epoxy, dependent on the resolution of the given image, the size of the averaging window, and the porosity components contained therein. The obtained quantifications of porosity can therefore only be regarded as ball-park relative porosities of a complete fault rock zones. It does not, however, provide firm

  7. Characterisation and modelling of mixing processes in groundwaters of a potential geological repository for nuclear wastes in crystalline rocks of Sweden.

    Science.gov (United States)

    Gómez, Javier B; Gimeno, María J; Auqué, Luis F; Acero, Patricia

    2014-01-15

    This paper presents the mixing modelling results for the hydrogeochemical characterisation of groundwaters in the Laxemar area (Sweden). This area is one of the two sites that have been investigated, under the financial patronage of the Swedish Nuclear Waste and Management Co. (SKB), as possible candidates for hosting the proposed repository for the long-term storage of spent nuclear fuel. The classical geochemical modelling, interpreted in the light of the palaeohydrogeological history of the system, has shown that the driving process in the geochemical evolution of this groundwater system is the mixing between four end-member waters: a deep and old saline water, a glacial meltwater, an old marine water, and a meteoric water. In this paper we put the focus on mixing and its effects on the final chemical composition of the groundwaters using a comprehensive methodology that combines principal component analysis with mass balance calculations. This methodology allows us to test several combinations of end member waters and several combinations of compositional variables in order to find optimal solutions in terms of mixing proportions. We have applied this methodology to a dataset of 287 groundwater samples from the Laxemar area collected and analysed by SKB. The best model found uses four conservative elements (Cl, Br, oxygen-18 and deuterium), and computes mixing proportions with respect to three end member waters (saline, glacial and meteoric). Once the first order effect of mixing has been taken into account, water-rock interaction can be used to explain the remaining variability. In this way, the chemistry of each water sample can be obtained by using the mixing proportions for the conservative elements, only affected by mixing, or combining the mixing proportions and the chemical reactions for the non-conservative elements in the system, establishing the basis for predictive calculations. © 2013 Elsevier B.V. All rights reserved.

  8. Site investigations: Strategy for rock mechanics site descriptive model

    International Nuclear Information System (INIS)

    Andersson, Johan; Christiansson, Rolf; Hudson, John

    2002-05-01

    As a part of the planning work for the Site Investigations, SKB has developed a Rock Mechanics Site Descriptive Modelling Strategy. Similar strategies are being developed for other disciplines. The objective of the strategy is that it should guide the practical implementation of evaluating site specific data during the Site Investigations. It is also understood that further development may be needed. This methodology enables the crystalline rock mass to be characterised in terms of the quality at different sites, for considering rock engineering constructability, and for providing the input to numerical models and performance assessment calculations. The model describes the initial stresses and the distribution of deformation and strength properties of the intact rock, of fractures and fracture zones, and of the rock mass. The rock mass mechanical properties are estimated by empirical relations and by numerical simulations. The methodology is based on estimation of mechanical properties using both empirical and heroretical/numerical approaches; and estimation of in situ rock stress using judgement and numerical modelling, including the influence of fracture zones. These approaches are initially used separately, and then combined to produce the required characterisation estimates. The methodology was evaluated with a Test Case at the Aespoe Hard Rock Laboratory in Sweden. The quality control aspects are an important feature of the methodology: these include Protocols to ensure the structure and coherence of the procedures used, regular meetings to enhance communication, feedback from internal and external reviewing, plus the recording of an audit trail of the development steps and decisions made. The strategy will be reviewed and, if required, updated as appropriate

  9. Site investigations: Strategy for rock mechanics site descriptive model

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Johan [JA Streamflow AB, Aelvsjoe (Sweden); Christiansson, Rolf [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Hudson, John [Rock Engineering Consultants, Welwyn Garden City (United Kingdom)

    2002-05-01

    As a part of the planning work for the Site Investigations, SKB has developed a Rock Mechanics Site Descriptive Modelling Strategy. Similar strategies are being developed for other disciplines. The objective of the strategy is that it should guide the practical implementation of evaluating site specific data during the Site Investigations. It is also understood that further development may be needed. This methodology enables the crystalline rock mass to be characterised in terms of the quality at different sites, for considering rock engineering constructability, and for providing the input to numerical models and performance assessment calculations. The model describes the initial stresses and the distribution of deformation and strength properties of the intact rock, of fractures and fracture zones, and of the rock mass. The rock mass mechanical properties are estimated by empirical relations and by numerical simulations. The methodology is based on estimation of mechanical properties using both empirical and heroretical/numerical approaches; and estimation of in situ rock stress using judgement and numerical modelling, including the influence of fracture zones. These approaches are initially used separately, and then combined to produce the required characterisation estimates. The methodology was evaluated with a Test Case at the Aespoe Hard Rock Laboratory in Sweden. The quality control aspects are an important feature of the methodology: these include Protocols to ensure the structure and coherence of the procedures used, regular meetings to enhance communication, feedback from internal and external reviewing, plus the recording of an audit trail of the development steps and decisions made. The strategy will be reviewed and, if required, updated as appropriate.

  10. Model validation and the role of the proposed Rock Characterisation Facility at Sellafield. Proof of evidence

    International Nuclear Information System (INIS)

    Wallace, H.

    1996-01-01

    Proof of Evidence is given by an expert witness on behalf of Greenpeace Ltd as part of their submission to a Planning Inquiry in 1995 hearing the application of UK Nirex Ltd for permission to construct an underground Rock Characterisation Facility (RCF) at a site near Sellafield. The RCF is part of an investigation by Nirex into a suitable site for the disposal of radioactive waste. An examination of the groundwater flow models used by Nirex and the procedure for their validation have led to the following conclusions: no evidence has been presented by Nirex to show that the construction of the RCF will improve the confidence they claim to have in the site; the prospects are slim for validating the models of present groundwater flow so that they satisfy the criteria to meet the risk target; it is extremely unlikely that results from the RCF will increase confidence in a safety assessment of this site; all the evidence available to date suggests that the risk assessment is not, and will not become, robust to variations in flux through the repository. (1 figure; 8 references). (UK)

  11. Strategy for a Rock Mechanics Site Descriptive Model. Development and testing of the empirical approach

    Energy Technology Data Exchange (ETDEWEB)

    Roeshoff, Kennert; Lanaro, Flavio [Berg Bygg Konsult AB, Stockholm (Sweden); Lanru Jing [Royal Inst. of Techn., Stockholm (Sweden). Div. of Engineering Geology

    2002-05-01

    This report presents the results of one part of a wide project for the determination of a methodology for the determination of the rock mechanics properties of the rock mass for the so-called Aespoe Test Case. The Project consists of three major parts: the empirical part dealing with the characterisation of the rock mass by applying empirical methods, a part determining the rock mechanics properties of the rock mass through numerical modelling, and a third part carrying out numerical modelling for the determination of the stress state at Aespoe. All Project's parts were performed based on a limited amount of data about the geology and mechanical tests on samples selected from the Aespoe Database. This Report only considers the empirical approach. The purpose of the project is the development of a descriptive rock mechanics model for SKBs rock mass investigations for a final repository site. The empirical characterisation of the rock mass provides correlations with some of the rock mechanics properties of the rock mass such as the deformation modulus, the friction angle and cohesion for a certain stress interval and the uniaxial compressive strength. For the characterisation of the rock mass, several empirical methods were analysed and reviewed. Among those methods, some were chosen because robust, applicable and widespread in modern rock mechanics. Major weight was given to the well-known Tunnel Quality Index (Q) and Rock Mass Rating (RMR) but also the Rock Mass Index (RMi), the Geological Strength Index (GSI) and Ramamurthy's Criterion were applied for comparison with the two classical methods. The process of: i) sorting the geometrical/geological/rock mechanics data, ii) identifying homogeneous rock volumes, iii) determining the input parameters for the empirical ratings for rock mass characterisation; iv) evaluating the mechanical properties by using empirical relations with the rock mass ratings; was considered. By comparing the methodologies involved

  12. Strategy for a Rock Mechanics Site Descriptive Model. Development and testing of the empirical approach

    International Nuclear Information System (INIS)

    Roeshoff, Kennert; Lanaro, Flavio; Lanru Jing

    2002-05-01

    This report presents the results of one part of a wide project for the determination of a methodology for the determination of the rock mechanics properties of the rock mass for the so-called Aespoe Test Case. The Project consists of three major parts: the empirical part dealing with the characterisation of the rock mass by applying empirical methods, a part determining the rock mechanics properties of the rock mass through numerical modelling, and a third part carrying out numerical modelling for the determination of the stress state at Aespoe. All Project's parts were performed based on a limited amount of data about the geology and mechanical tests on samples selected from the Aespoe Database. This Report only considers the empirical approach. The purpose of the project is the development of a descriptive rock mechanics model for SKBs rock mass investigations for a final repository site. The empirical characterisation of the rock mass provides correlations with some of the rock mechanics properties of the rock mass such as the deformation modulus, the friction angle and cohesion for a certain stress interval and the uniaxial compressive strength. For the characterisation of the rock mass, several empirical methods were analysed and reviewed. Among those methods, some were chosen because robust, applicable and widespread in modern rock mechanics. Major weight was given to the well-known Tunnel Quality Index (Q) and Rock Mass Rating (RMR) but also the Rock Mass Index (RMi), the Geological Strength Index (GSI) and Ramamurthy's Criterion were applied for comparison with the two classical methods. The process of: i) sorting the geometrical/geological/rock mechanics data, ii) identifying homogeneous rock volumes, iii) determining the input parameters for the empirical ratings for rock mass characterisation; iv) evaluating the mechanical properties by using empirical relations with the rock mass ratings; was considered. By comparing the methodologies involved by the

  13. Characterization of Geologic Structures and Host Rock Properties Relevant to the Hydrogeology of the Standard Mine in Elk Basin, Gunnison County, Colorado

    Science.gov (United States)

    Caine, Jonathan S.; Manning, Andrew H.; Berger, Byron R.; Kremer, Yannick; Guzman, Mario A.; Eberl, Dennis D.; Schuller, Kathryn

    2010-01-01

    The Standard Mine Superfund Site is a source of mine drainage and associated heavy metal contamination of surface and groundwaters. The site contains Tertiary polymetallic quartz veins and fault zones that host precious and base metal sulfide mineralization common in Colorado. To assist the U.S. Environmental Protection Agency in its effort to remediate mine-related contamination, we characterized geologic structures, host rocks, and their potential hydraulic properties to better understand the sources of contaminants and the local hydrogeology. Real time kinematic and handheld global positioning systems were used to locate and map precisely the geometry of the surface traces of structures and mine-related features, such as portals. New reconnaissance geologic mapping, field and x-ray diffraction mineralogy, rock sample collection, thin-section analysis, and elemental geochemical analysis were completed to characterize hydrothermal alteration, mineralization, and subsequent leaching of metallic phases. Surface and subsurface observations, fault vein and fracture network characterization, borehole geophysical logging, and mercury injection capillary entry pressure data were used to document potential controls on the hydrologic system.

  14. Geological data acquisition for site characterisation at Olkiluoto: a framework for the phase of underground investigations

    International Nuclear Information System (INIS)

    Milnes, A.G.; Aaltonen, I.; Kemppainen, K.; Mattila, J.; Wikstroem, L.; Front, K.; Kaerki, A.; Gehoer, S.; Paulamaeki, S.; Paananen, M.; Ahokas, T.

    2007-05-01

    'Geological data acquisition' is a general term for the collection of observations and measurements by direct observation of exposed bedrock in the field (i.e. in natural outcrops and trenches, in drillholes, and in tunnels and other underground excavations). Only field-based data acquisition is included in this report: laboratory-based investigations will be continued, based on the field data and sampling, and all the data will be subject to discipline-specific processing, as the project proceeds. The ultimate aim of geological data acquisition is to provide the necessary data base for geological models of the bedrock of the Olkiluoto site, in connection with the construction of an underground rock characterisation facility, ONKALO, and a repository for spent nuclear fuel, at about 500m depth. Geological data acquisition plays a central role in site characterisation and modelling, and is intended to provide a solid platform on which the other disciplines (rock mechanics, hydrogeology, seismic risk assessment, etc.) can base their investigations. Based on consideration of a series of guidelines (e.g. modelling scale, source of data, level of investigation, national and international experience, special conditions at Olkiluoto, need for process understanding), a project-oriented 'framework' has been developed as a background to the different projects within the geological data acquisition programme. Each project will require its own system of data acquisition (methodology, spreadsheets, protocols, etc.), as described in the corresponding reports; the present report concentrates on the general principles which lie behind the different methodologies and data sheets. These principles are treated under three main headings: characterization of intact rock, characterization of deformation zone intersections, and characterization of individual fractures. Geological mapping of natural outcrops and trenches at Olkiluoto, and lithological logging of more than 40 rock cores

  15. Low temperature geomicrobiology follows host rock composition along a geochemical gradient in Lau Basin

    Directory of Open Access Journals (Sweden)

    Jason B Sylvan

    2013-03-01

    Full Text Available The East Lau Spreading Center (ELSC and Valu Fa Ridge (VFR comprise a ridge segment in the southwest Pacific Ocean where rapid transitions in the underlying mantle chemistry manifest themselves as gradients in seafloor rock geochemistry. We studied the geology and microbial diversity of three silicate rock samples and three inactive sulfide chimney samples collected, from north to south, at the vent fields Kilo Moana, ABE, Tui Malila and Mariner. This is the first study of microbial populations on basaltic andesite, which was sampled at Mariner vent field. Silicate rock geochemistry exhibits clear latitudinal trends that are mirrored by changes in bacterial community composition. α-proteobacteria, ε-proteobacteria and Bacteroidetes are most common on a silicate collected from Kilo Moana and their proportions decrease linearly on silicates collected further south. Conversely, a silicate from Mariner vent field hosts high proportions of a unique lineage of Chloroflexi unrelated (<90% sequence similarity to previously recovered environmental clones or isolates, which decrease at ABE and are absent at Kilo Moana. The exteriors of inactive sulfide structures are dominated by lineages of sulfur oxidizing α-proteobacteria, γ-proteobacteria and ε-proteobacteria while the interior of one chimney is dominated by putative sulfur-reducing δ-proteobacteria. A comparison of bacterial communities on inactive sulfides from this and previous studies reveals the presence of a clade of uncultured Bacteroidetes exclusive to sulfidic environments, and a high degree of heterogeneity in bacterial community composition from one sulfide structure to another. In light of the heterogeneous nature of bacterial communities observed here and in previous studies of both active and inactive hydrothermal sulfide structures, the presence of numerous niches may be detected on these structures in the future by finer scale sampling and analysis.

  16. The Rock Characterization Facility

    International Nuclear Information System (INIS)

    Holmes, J.

    1994-01-01

    In 1989, UK Nirex began a programme of surface-based characterization of the geology and hydrogeology of a site at Sellafield to evaluate its suitability to host a deep repository for radioactive waste. The next major stage in site characterization will be the construction and operation of a Rock Characterization Facility (RCF). It will be designed to provide rock characterization information and scope for model validation to permit firmer assessment of long-term safety. It will also provide information needed to decide the detailed location, design and orientation of a repository and to inform repository construction methods. A three-phase programme is planned for the RCF. During each phase, testwork will steadily improve our geological, hydrogeological and geotechnical understanding of the site. The first phase will involve sinking two shafts. That will be preceded by the establishment of a network of monitoring boreholes to ensure that the impact of shaft sinking can be measured. This will provide valuable data for model validation. In phase two, initial galleries will be excavated, probably at a depth of 650 m below Ordnance datum, which will host a comprehensive suite of experiments. These galleries will be extended in phase three to permit access to most of the rock volume that would host the repository. (Author)

  17. Hydrological evaluation of five sedimentary rocks for high-level waste disposal

    International Nuclear Information System (INIS)

    Lomenick, T.F.; Kanehiro, B.Y.

    1986-01-01

    Utilizing performance criteria that are based upon siting guidelines issued by DOE for postclosure as well as preclosure conditions, a preliminary hydrologic evaluation and ranking is being conducted to determine the suitability of five sedimentary rocks as potential host rocks for a high-level radioactive waste repository. Based upon both quantitative and qualitative considerations, the hydrological ranking of the rocks in order of their potential as a host rock for the disposal of radioactive wastes would be shale, anhydrock, sandstone, chalk, and carbonates, with the first three rocks being significantly better than the remaining two types

  18. Proceedings of the scientific visit on crystalline rock repository development.

    Energy Technology Data Exchange (ETDEWEB)

    Mariner, Paul E.; Hardin, Ernest L.; Miksova, Jitka [RAWRA, Czech Republic

    2013-02-01

    A scientific visit on Crystalline Rock Repository Development was held in the Czech Republic on September 24-27, 2012. The visit was hosted by the Czech Radioactive Waste Repository Authority (RAWRA), co-hosted by Sandia National Laboratories (SNL), and supported by the International Atomic Energy Agency (IAEA). The purpose of the visit was to promote technical information exchange between participants from countries engaged in the investigation and exploration of crystalline rock for the eventual construction of nuclear waste repositories. The visit was designed especially for participants of countries that have recently commenced (or recommenced) national repository programmes in crystalline host rock formations. Discussion topics included repository programme development, site screening and selection, site characterization, disposal concepts in crystalline host rock, regulatory frameworks, and safety assessment methodology. Interest was surveyed in establishing a %E2%80%9Cclub,%E2%80%9D the mission of which would be to identify and address the various technical challenges that confront the disposal of radioactive waste in crystalline rock environments. The idea of a second scientific visit to be held one year later in another host country received popular support. The visit concluded with a trip to the countryside south of Prague where participants were treated to a tour of the laboratory and underground facilities of the Josef Regional Underground Research Centre.

  19. Thermal effects of the Santa Eulália Plutonic Complex (southern Portugal on the meta-igneous and metasedimentary host rocks

    Directory of Open Access Journals (Sweden)

    Cruz, C.

    2014-12-01

    Full Text Available The Santa Eulália Plutonic Complex (SEPC is a late-Variscan granitic body located in the northern part of the Ossa Morena Zone, a inner zone of the Variscan Iberian Massif. The SEPC host rocks are composed of meta-igneous and metasedimentary units, from Upper Proterozoic to Paleozoic ages, with a NW-SE structure, cross-cut by the SEPC. The SEPC host rocks, with low grade metamorphism show well preserved primary sedimentary or igneous mineralogical, textural and structural features. The thermal effect induced by the SEPC is restricted to the roof pendants. At N and NE of the SEPC, textures and paragenesis resulting from thermal metamorphism, are not related to the SEPC intrusion but to a previous magmatism, controlled by the NW-SE regional anisotropies. The restriction of the thermal effects to the pluton roof may be caused by a combination of several interrelated factors: higher volume of granitic mass, thermal effect by advection of fluids and longer period of prevalence of high thermal conditions. The geochemical study of SEPC host rocks shows the heterogeneous character and diversity of metasedimentary, igneous and meta-igneous rocks. The whole rock geochemical data indicate that all the metasedimentary lithologies derived from an upper continental crustal source and the igneous and meta-igneous rocks show no evidence of metasomatic effects by the SEPC emplacement.El Complejo Plutónico de Santa Eulalia (CPSE es un cuerpo granítico tardi-Varisco situado en la parte norte de la Zona de Ossa Morena, en la zona interior del Macizo Ibérico Varisco. Las rocas encajantes del CPSE están compuestas por unidades meta-ígneas y metasedimentarias, de edades que van desde el Proterozoico Superior hasta el Paleozoico, con una estructura de dirección NW-SE, cortada por el CPSE. Las rocas encanjantes del CPSE, con metamorfismo de bajo grado conservan estructuras, mineralogía y textura primarias. El efecto térmicoinducido por el CPSE se limita a los

  20. Hosting Early Evolution in Heated Pores of Rock

    Science.gov (United States)

    Mast, C. B.; Möller, F.; Lanzmich, S.; Keil, L.; Braun, D.

    2017-07-01

    Recent experiments with non-equilibrium micro­systems suggest that porous rock conditions drive early molecular evolution in many ways, including accumulation, polymerization, replication, length selection and gelation.

  1. Age and geochemistry of host rocks of the Cobre Panama porphyry Cu-Au deposit, central Panama: Implications for the Paleogene evolution of the Panamanian magmatic arc

    Science.gov (United States)

    Baker, Michael J.; Hollings, Peter; Thompson, Jennifer A.; Thompson, Jay M.; Burge, Colin

    2016-04-01

    The Cobre Panama porphyry Cu-Au deposit, located in the Petaquilla district of central Panama, is hosted by a sequence of medium- to high-K calc-alkaline volcanic and sub-volcanic rocks. New crystallisation ages obtained from a granodiorite Petaquilla batholith and associated mineralised diorite to granodiorite porphyry stocks and dikes at Cobre Panama indicate that the batholith was emplaced as a multi-phase intrusion, over a period of 4 million years from 32.20 ± 0.76 Ma to 28.26 ± 0.61 Ma, while the porphyritic rocks were emplaced over a 2 million year period from 28.96 ± 0.62 Ma to 27.48 ± 0.68 Ma. Both the volcanic to sub-volcanic host rocks and intrusive rocks of the Cobre Panama deposit evolved via fractional crystallisation processes, as demonstrated by the major elements (e.g. Al2O3, Fe2O3, TiO2 and MgO) displaying negative trends with increasing SiO2. The Petaquilla intrusive rocks, including the diorite-granodiorite porphyries and granodiorite batholith, are geochemically evolved and appear to have formed from more hydrous magmas than the preceding host volcanic rocks, as evidenced by the presence of hornblende phenocrysts, higher degrees of large-ion lithophile element (LILE) and light rare earth element (LREE) enrichment and heavy rare earth element (HREE) depletion, and higher Sr/Y and La/Yb values. However, the degree of LREE enrichment, HREE depletion and La/Yb values are insufficient for the intrusive rocks to be considered as adakites. Collectively, the volcanic and intrusive rocks have LILE, REE and mobile trace element concentrations similar to enriched Miocene-age Cordilleran arc magmatism found throughout central and western Panama. Both the Petaquilla and Cordilleran arc magmatic suites are geochemically more evolved than the late Cretaceous to Eocene Chagres-Bayano arc magmas from northeastern Panama, as they display higher degrees of LILE and LREE enrichment. The geochemical similarities between the Petaquilla and Cordilleran arc magmas

  2. Repository for high level radioactive wastes in Brazil: the importance of geochemical (Micro thermometric) studies and fluid migration in potential host rocks; Repositorios para rejeitos radioativos de alto nivel (RANR) no Brasil: a importancia de estudos geoquimicos (microtermometricos) e de migracao de fluidos em rochas potenciamente hospedeiras

    Energy Technology Data Exchange (ETDEWEB)

    Rios, Francisco Javier; Fuzikawa, Kazuo; Alves, James Vieira; Neves, Jose Marques Correia [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN-CNEN-MG), Belo Horizonte, MG (Brazil). Lab. de Inclusoes Fluidas e Metalogenese]. E-mail: javier@cdtn.br

    2003-04-15

    A detailed fluid inclusion study of host rocks, is of fundamental importance in the selection of geologically suitable areas for high level nuclear waste repository constructions (HLRW). The LIFM-CDTN is enabled to develop studies that confirm: the presence or not, of corrosive fluid in minerals from host rocks of the repository and the possible presence of micro fractures (and fluid leakage) when these rocks are submitted to high temperatures. These fluid geochemistry studies, with permeability determinations by means of pressurized air injection must be carried out in rocks hosting nuclear waste. Micro fracture determination is of vital importance since many naturally corrosive solutions, present in the mineral rocks, could flow out through these plans affecting the walls of the repository. (author)

  3. Trace element characterisation of Cretaceous Orange Basin hydrocarbon source rocks

    International Nuclear Information System (INIS)

    Akinlua, A.; Adekola, S.A.; Swakamisa, O.; Fadipe, O.A.; Akinyemi, S.A.

    2010-01-01

    Research highlights: → Vanadium and nickel contents indicate that the rock samples from the Orange Basin have marine organic matter input. → The organic matter of the Orange Basin source rocks were deposited in reducing conditions. → Despite the similarities in the organic matter source input and depositional environment of the samples from the two well, cross plots of Co/Ni versus V/Ni and Mo/Ni versus Co/Ni were able to reveal their subtle differences. → Cluster analysis classified the samples into three groups based on subtle differences in their .thermal maturity. - Abstract: Trace elements in the kerogen fraction of hydrocarbon source rock samples from two wells obtained from the Cretaceous units of the Orange Basin, South Africa were determined using X-ray fluorescence spectrometry, in order to determine their distribution and geochemical significances. The concentrations of the elements (As, Ce, Co, Cu, Fe, Mo, Ni, Pb and V) determined ranged from 0.64 to 47,300 ppm for the samples analysed. The total organic carbon (TOC) values indicate that the samples are organic rich but did not show any trend with the distribution of the trace metals except Ce, Mo and Pb. Dendrogram cluster analysis discriminated the samples into three groups on the basis of their level of thermal maturity. Thermal maturity has a significant effect on the distribution of the trace metals. Cobalt/Ni and V/Ni ratios and cross plots of the absolute values of V and Ni indicate that the samples had significant marine organic matter input. The V and Ni contents and V/(V + Ni) ratio indicate that the organic matter of the source rocks had been deposited in reducing conditions. Despite the similarities in the organic matter source input and depositional environment of the organic matter of the samples from the two well, cross plots of Co/Ni versus V/Ni and Mo/Ni versus Co/Ni were able to reveal subtle differences. Cluster analysis of the samples was also able to reveal the subtle

  4. 10 CFR 960.5-2-9 - Rock characteristics.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Rock characteristics. 960.5-2-9 Section 960.5-2-9 Energy... Rock characteristics. (a) Qualifying condition. The site shall be located such that (1) the thickness and lateral extent and the characteristics and composition of the host rock will be suitable for...

  5. Dynamic characterisation of the specific surface area for fracture networks

    Science.gov (United States)

    Cvetkovic, V.

    2017-12-01

    One important application of chemical transport is geological disposal of high-level nuclear waste for which crystalline rock is a prime candidate for instance in Scandinavia. Interconnected heterogeneous fractures of sparsely fractured rock such as granite, act as conduits for transport of dissolved tracers. Fluid flow is known to be highly channelized in such rocks. Channels imply narrow flow paths, adjacent to essentially stagnant water in the fracture and/or the rock matrix. Tracers are transported along channelised flow paths and retained by minerals and/or stagnant water, depending on their sorption properties; this mechanism is critical for rocks to act as a barrier and ultimately provide safety for a geological repository. The sorbing tracers are retained by diffusion and sorption on mineral surfaces, whereas non-sorbing tracers can be retained only by diffusion into stagnant water of fractures. The retention and transport properties of a sparsely fractured rock will primarily depend on the specific surface area (SSA) of the fracture network which is determined by the heterogeneous structure and flow. The main challenge when characterising SSA on the field-scale is its dependence on the flow dynamics. We first define SSA as a physical quantity and clarify its importance for chemical transport. A methodology for dynamic characterisation of SSA in fracture networks is proposed that relies on three sets of data: i) Flow rate data as obtained by a flow logging procedure; ii) transmissivity data as obtained by pumping tests; iii) fracture network data as obtained from outcrop and geophysical observations. The proposed methodology utilises these data directly as well as indirectly through flow and particle tracking simulations in three-dimensional discrete fracture networks. The methodology is exemplified using specific data from the Swedish site Laxemar. The potential impact of uncertainties is of particular significance and is illustrated for radionuclide

  6. Aespoe Hard Rock Laboratory Annual report 2003

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-09-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a deep geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site for a deep repository. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create an opportunity for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. Aespoe HRL has been in operation since 1995 and the associated research, development, and demonstration tasks, have so far attracted considerable interest. A summary of work performed at Aespoe HRL during 2003 is given below. Seven organisations from six countries participated in the co-operation at Aespoe HRL during 2003 in addition to SKB. Most of the organisations are interested in groundwater flow, radionuclide transport and rock characterisation. Several of the organisations are participating in the experimental work as well as in the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes. SKB is through Repository Technology co-ordinating three EC contracts and takes part in several EC projects of which the representation in five projects is channelled through Repository Technology. SKB takes also part in work within the IAEA framework.

  7. Aespoe Hard Rock Laboratory Annual report 2003

    International Nuclear Information System (INIS)

    2004-09-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a deep geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site for a deep repository. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create an opportunity for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. Aespoe HRL has been in operation since 1995 and the associated research, development, and demonstration tasks, have so far attracted considerable interest. A summary of work performed at Aespoe HRL during 2003 is given below. Seven organisations from six countries participated in the co-operation at Aespoe HRL during 2003 in addition to SKB. Most of the organisations are interested in groundwater flow, radionuclide transport and rock characterisation. Several of the organisations are participating in the experimental work as well as in the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes. SKB is through Repository Technology co-ordinating three EC contracts and takes part in several EC projects of which the representation in five projects is channelled through Repository Technology. SKB takes also part in work within the IAEA framework

  8. Requirements of actual final repository concepts for different host rock formations. Final report; Anforderungen an aktuelle Endlagerkonzepte fuer unterschiedliche Wirtsgesteinsformationen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Fass, Thorsten; Hartwig-Thurat, Eva; Krischer, Angelika; Lambers, Ludger; Larue, Juergen; Uhlmann, Stephan; Weyand, Torben

    2017-08-15

    In the frame of the research project the basic requirements and technical safety specifications with respect to the retrievability of stored radioactive wastes for the different final repository concepts based on the host rock formations occurring in Germany are presented. Existing international disposal concepts for clay/claystone, granite and salt are described and compared to the actual German regulatory requirements. The safety engineering relations between stock piling and possible retrieval are described and evaluated.

  9. Properties of uranium and thorium in host rocks of multi-metal (Ag, Pb, U, Cu, Bi, Z, F) Big Kanimansur deposit (Tajikistan)

    International Nuclear Information System (INIS)

    Fayziev, A.R.

    2007-01-01

    Multi-metal Big Kanimansur Deposit host rocks contain high averages of uranium and thorium which are more than clark averages by 7 and 2.5 times accordingly. The second property of radio-active elements distribution are low ratio of thorium to uranium. That criteria can be used as prospecting sings for flanks and depth of know ore fields as well as for new squares of multi-metal mineralisation

  10. Moessbauer and XRD Comparative Study of Host Rock and Iron Rich Mineral Samples from Paz del Rio Iron Ore Mineral Mine in Colombia

    International Nuclear Information System (INIS)

    Fajardo, M.; Perez Alcazar, G. A.; Moreira, A. M.; Speziali, N. L.

    2004-01-01

    A comparative study between the host rock and the iron rich mineral samples from the Paz del Rio iron ore mineral mine in Colombia was performed using X-ray diffraction and Moessbauer spectroscopy. Diffraction results of the iron rich mineral sample show that goethite, hematite, quartz, kaolinite and siderite are the main phases, and that a small amount of illite is also present. By Moessbauer spectroscopy at room temperature (RT) the presence of all the above mentioned phases was detected except quartz as well as an additional presence of small amount of biotite. The goethite, which appears as four sextets with hyperfine fields of 33.5, 30.5, 27.5 and 18.5 T, respectively, is the majority phase. This result shows the different grades of formation of this oxyhydroxide. The Moessbauer spectrum of this sample at 80 K presents the same phases obtained at RT without any superparamagnetic effect. In this case the goethite appears as two sextets. Diffraction results of the host rock sample show a large amount of quartz and kaolinite and small amounts of illite and biotite, whereas by Moessbauer spectroscopy illite, kaolinite and biotite were detected.

  11. Characterisation of gas transport properties of the Opalinus clay, a potential host rock formation for radioactive waste disposal; Caracterisation des proprietes des argiles d'Opalinus (roche d'accueil potentielle pour un stockage de dechets radioactifs) relatives au transport des gaz

    Energy Technology Data Exchange (ETDEWEB)

    Marschall, P. [Nagra - National Cooperative for the Disposal of Radioactive Waste, Wettingen (Switzerland); Horseman, S. [British Geological Survey, Kingsley Dunham Centre, Keyworth (United Kingdom); Gimmi, T. [Bern Univ. (Switzerland); Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    2005-07-01

    The Opalinus Clay in Northern Switzerland has been identified as a potential host rock formation for the disposal of radioactive waste. Comprehensive understanding of gas transport processes through this low-permeability formation forms a key issue in the assessment of repository performance. Field investigations and laboratory experiments suggest an intrinsic permeability of the Opalinus Clay in the order of 10{sup -20} to 10{sup -21} m{sup 2} and a moderate anisotropy ratio {<=} 10. Porosity depends on clay content and burial depth; values of {approx} 0.12 are reported for the region of interest. Porosimetry indicates that about 10-30% of voids can be classed as macro-pores, corresponding to an equivalent pore radius > 25 nm. The determined entry pressures are in the range of 0.4-10 MPa and exhibit a marked dependence on intrinsic permeability. Both in situ gas tests and gas permeameter tests on drill-cores demonstrate that gas transport through the rock is accompanied by pore water displacement, suggesting that classical flow concepts of immiscible displacement in porous media can be applied when the gas entry pressure (i.e. capillary threshold pressure) is less than the minimum principal stress acting within the rock. Essentially, the pore space accessible to gas flow is restricted to the network of connected macro-pores, which implies a very low degree of desaturation of the rock during the gas imbibition process. At elevated gas pressures (i.e. when gas pressure approaches the level of total stress that acts on the rock body), evidence was seen for dilatancy controlled gas transport mechanisms. Further field experiments were aimed at creating extended tensile fractures with high fracture transmissivity (hydro- or gas-fractures). The test results lead to the conclusion that gas fracturing can be largely ruled out as a risk for post-closure repository performance. (authors)

  12. Pore water colloid properties in argillaceous sedimentary rocks

    Energy Technology Data Exchange (ETDEWEB)

    Degueldre, Claude, E-mail: c.degueldre@lancaster.ac.uk [Engineering Department, University of Lancaster, LA1 4YW Lancaster (United Kingdom); ChiAM & Institute of Environment, University of Geneva, 1211 Genève 4, Swizerland (Switzerland); Earlier, NES, Paul Scherrer Institute, 5232 Villigen (Switzerland); Cloet, Veerle [NAGRA, Hardstrasse 73, 5430 Wettingen (Switzerland)

    2016-11-01

    The focus of this work is to evaluate the colloid nature, concentration and size distribution in the pore water of Opalinus Clay and other sedimentary host rocks identified for a potential radioactive waste repository in Switzerland. Because colloids could not be measured in representative undisturbed porewater of these host rocks, predictive modelling based on data from field and laboratory studies is applied. This approach allowed estimating the nature, concentration and size distributions of the colloids in the pore water of these host rocks. As a result of field campaigns, groundwater colloid concentrations are investigated on the basis of their size distribution quantified experimentally using single particle counting techniques. The colloid properties are estimated considering data gained from analogue hydrogeochemical systems ranging from mylonite features in crystalline fissures to sedimentary formations. The colloid concentrations were analysed as a function of the alkaline and alkaline earth element concentrations. Laboratory batch results on clay colloid generation from compacted pellets in quasi-stagnant water are also reported. Experiments with colloids in batch containers indicate that the size distribution of a colloidal suspension evolves toward a common particle size distribution independently of initial conditions. The final suspension size distribution was found to be a function of the attachment factor of the colloids. Finally, calculations were performed using a novel colloid distribution model based on colloid generation, aggregation and sedimentation rates to predict under in-situ conditions what makes colloid concentrations and size distributions batch- or fracture-size dependent. The data presented so far are compared with the field and laboratory data. The colloid occurrence, stability and mobility have been evaluated for the water of the considered potential host rocks. In the pore water of the considered sedimentary host rocks, the clay

  13. Mineralogy and geochemistry of Skarn Fe orebody and syenodioritic intrusive host rock in Zeber Kuh prospect area (SW Bardaskan, South Khorasan province

    Directory of Open Access Journals (Sweden)

    Hossein Narooie

    2017-11-01

    Full Text Available The Zeber Kuh prospect area is located southwest of Bardaskan, South Khorasan province, in the northeastern Iran. Lithologically, the area includes Rizu and Soltanieh Formations metamorphosed carbonate rocks, which were intruded by syenogranitic and syenodioritic intrusions. Field observations and laboratory studies such as structural controls of orebody, metasomatic replacement and formation of low temperature H2O-bearing minerals, and the occurrence of magnetite and pyrite associated with chlorite, epidote, calcite, and quartz indicate that  the iron mineralization is low temperature skarn-type. The source of Fe mineralization is probably a younger intrusive rock at depth. Hydrothermal ore fluid was ascended within fault zone and/or contact between the intrusive rock and the  carbonate unit and generated orebody. Iron grade ranges from 54 to 65 wt.% and sulfur value is > 3 wt.%. Magnetite chemistry and Ti, V, Al, Mn, Ni, and Cr contents are similar to skarn deposit. Biotite syenodiorite host rock has hypidiomorphic granular texture and it consists of plagioclase, K-feldspar, biotite, and apatite minerals. Chemically, this intrusive rock is K-series alkaline type, which was generated in within plate zone. This magma is characterized by strong enrichment in LREE, LILE (Rb, Cs, Ba, and K, HFSE (Nb, Zr, and Ti, and P elements. The primary magma is produced by low degree partial melting of garnet lherzolite from asthenospheric to boundary of asthenospheric-lithospheric mantle.

  14. 10 CFR 960.3-1-2 - Diversity of rock types.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Diversity of rock types. 960.3-1-2 Section 960.3-1-2... NUCLEAR WASTE REPOSITORY Implementation Guidelines § 960.3-1-2 Diversity of rock types. Consideration... sites for characterization shall have different types of host rock. ...

  15. Interim rock mass properties and conditions for analyses of a repository in crystalline rock

    International Nuclear Information System (INIS)

    Tammemagi, H.Y.; Chieslar, J.D.

    1985-03-01

    A summary of rock properties for generic crystalline rock is compiled from literature sources to provide the input data for analyses of a conceptual repository in crystalline rock. Frequency histograms, mean values and ranges of physical, mechanical, thermal, and thermomechanical properties, and the dependence of these properties on temperature are described. A description of the hydrogeologic properties of a crystalline rock mass and their dependence on depth is provided. In addition, the temperature gradients, mean annual surface temperature, and in situ stress conditions are summarized for the three regions of the United States currently under consideration to host a crystalline repository; i.e., the North Central, Northeastern, and Southeastern. Brief descriptions of the regional geology are also presented. Large-scale underground experiments in crystalline rock at Stripa, Sweden, and in Climax Stock in Nevada, are reviewed to assess whether the rock properties presented in this report are representative of in situ conditions. The suitability of each rock property and the sufficiency of its data base are described. 110 refs., 27 figs., 4 tabs

  16. Pore water colloid properties in argillaceous sedimentary rocks.

    Science.gov (United States)

    Degueldre, Claude; Cloet, Veerle

    2016-11-01

    The focus of this work is to evaluate the colloid nature, concentration and size distribution in the pore water of Opalinus Clay and other sedimentary host rocks identified for a potential radioactive waste repository in Switzerland. Because colloids could not be measured in representative undisturbed porewater of these host rocks, predictive modelling based on data from field and laboratory studies is applied. This approach allowed estimating the nature, concentration and size distributions of the colloids in the pore water of these host rocks. As a result of field campaigns, groundwater colloid concentrations are investigated on the basis of their size distribution quantified experimentally using single particle counting techniques. The colloid properties are estimated considering data gained from analogue hydrogeochemical systems ranging from mylonite features in crystalline fissures to sedimentary formations. The colloid concentrations were analysed as a function of the alkaline and alkaline earth element concentrations. Laboratory batch results on clay colloid generation from compacted pellets in quasi-stagnant water are also reported. Experiments with colloids in batch containers indicate that the size distribution of a colloidal suspension evolves toward a common particle size distribution independently of initial conditions. The final suspension size distribution was found to be a function of the attachment factor of the colloids. Finally, calculations were performed using a novel colloid distribution model based on colloid generation, aggregation and sedimentation rates to predict under in-situ conditions what makes colloid concentrations and size distributions batch- or fracture-size dependent. The data presented so far are compared with the field and laboratory data. The colloid occurrence, stability and mobility have been evaluated for the water of the considered potential host rocks. In the pore water of the considered sedimentary host rocks, the clay

  17. Porosity, permeability and 3D fracture network characterisation of dolomite reservoir rock samples.

    Science.gov (United States)

    Voorn, Maarten; Exner, Ulrike; Barnhoorn, Auke; Baud, Patrick; Reuschlé, Thierry

    2015-03-01

    With fractured rocks making up an important part of hydrocarbon reservoirs worldwide, detailed analysis of fractures and fracture networks is essential. However, common analyses on drill core and plug samples taken from such reservoirs (including hand specimen analysis, thin section analysis and laboratory porosity and permeability determination) however suffer from various problems, such as having a limited resolution, providing only 2D and no internal structure information, being destructive on the samples and/or not being representative for full fracture networks. In this paper, we therefore explore the use of an additional method - non-destructive 3D X-ray micro-Computed Tomography (μCT) - to obtain more information on such fractured samples. Seven plug-sized samples were selected from narrowly fractured rocks of the Hauptdolomit formation, taken from wellbores in the Vienna basin, Austria. These samples span a range of different fault rocks in a fault zone interpretation, from damage zone to fault core. We process the 3D μCT data in this study by a Hessian-based fracture filtering routine and can successfully extract porosity, fracture aperture, fracture density and fracture orientations - in bulk as well as locally. Additionally, thin sections made from selected plug samples provide 2D information with a much higher detail than the μCT data. Finally, gas- and water permeability measurements under confining pressure provide an important link (at least in order of magnitude) towards more realistic reservoir conditions. This study shows that 3D μCT can be applied efficiently on plug-sized samples of naturally fractured rocks, and that although there are limitations, several important parameters can be extracted. μCT can therefore be a useful addition to studies on such reservoir rocks, and provide valuable input for modelling and simulations. Also permeability experiments under confining pressure provide important additional insights. Combining these and

  18. 10 CFR 960.4-2-3 - Rock characteristics.

    Science.gov (United States)

    2010-01-01

    ... DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Postclosure Guidelines § 960.4-2-3 Rock characteristics. (a) Qualifying condition. The present and... the waste could significantly decrease the isolation provided by the host rock as compared with pre...

  19. Numerical modelling of fluid-rock interactions: Lessons learnt from carbonate rocks diagenesis studies

    Science.gov (United States)

    Nader, Fadi; Bachaud, Pierre; Michel, Anthony

    2015-04-01

    Quantitative assessment of fluid-rock interactions and their impact on carbonate host-rocks has recently become a very attractive research topic within academic and industrial realms. Today, a common operational workflow that aims at predicting the relevant diagenetic processes on the host rocks (i.e. fluid-rock interactions) consists of three main stages: i) constructing a conceptual diagenesis model including inferred preferential fluids pathways; ii) quantifying the resulted diagenetic phases (e.g. depositing cements, dissolved and recrystallized minerals); and iii) numerical modelling of diagenetic processes. Most of the concepts of diagenetic processes operate at the larger, basin-scale, however, the description of the diagenetic phases (products of such processes) and their association with the overall petrophysical evolution of sedimentary rocks remain at reservoir (and even outcrop/ well core) scale. Conceptual models of diagenetic processes are thereafter constructed based on studying surface-exposed rocks and well cores (e.g. petrography, geochemistry, fluid inclusions). We are able to quantify the diagenetic products with various evolving techniques and on varying scales (e.g. point-counting, 2D and 3D image analysis, XRD, micro-CT and pore network models). Geochemical modelling makes use of thermodynamic and kinetic rules as well as data-bases to simulate chemical reactions and fluid-rock interactions. This can be through a 0D model, whereby a certain process is tested (e.g. the likelihood of a certain chemical reaction to operate under specific conditions). Results relate to the fluids and mineral phases involved in the chemical reactions. They could be used as arguments to support or refute proposed outcomes of fluid-rock interactions. Coupling geochemical modelling with transport (reactive transport model; 1D, 2D and 3D) is another possibility, attractive as it provides forward simulations of diagenetic processes and resulting phases. This

  20. Alteration of national glass in radioactive waste repository host rocks: A conceptional review

    International Nuclear Information System (INIS)

    Apps, J.A.

    1987-01-01

    The storage of high-level radioactive wastes in host rocks containing natural glass has potential chemical advantages, especially if the initial waste temperatures are as high as 250 0 C. However, it is not certain how natural glasses will decompose when exposed to an aqueous phase in a repository environment. The hydration and devitrification of both rhyolitic and natural basaltic natural glasses are reviewed in the context of hypothetical thermodynamic phase relations, infrared spectroscopic data and laboratory studies of synthetic glasses exposed to steam. The findings are compared with field observations and laboratory studies of hydrating and devitrifying natural glasses. The peculiarities of the dependence of hydration and devitrification behavior on compositional variation is noted. There is substantial circumstantial evidence to support the belief that rhyolitic glasses differ from basaltic glasses in their thermodynamic stability and their lattice structure, and that this is manifested by a tendency of the former to hydrate rather than devitrify when exposed to water. Further research remains to be done to confirm the differences in glass structure, and to determine both physically and chemically dependent properties of natural glasses as a function of composition

  1. Characterisation of North American Brucella isolates from marine mammals.

    Science.gov (United States)

    Whatmore, Adrian M; Dawson, Claire; Muchowski, Jakub; Perrett, Lorraine L; Stubberfield, Emma; Koylass, Mark; Foster, Geoffrey; Davison, Nicholas J; Quance, Christine; Sidor, Inga F; Field, Cara L; St Leger, Judy

    2017-01-01

    Extension of known ecological niches of Brucella has included the description of two novel species from marine mammals. Brucella pinnipedialis is associated predominantly with seals, while two major Brucella ceti clades, most commonly associated with porpoises or dolphins respectively, have been identified. To date there has been limited characterisation of Brucella isolates obtained from marine mammals outside Northern European waters, including North American waters. To address this gap, and extend knowledge of the global population structure and host associations of these Brucella species, 61 isolates from marine mammals inhabiting North American waters were subject to molecular and phenotypic characterisation enabling comparison with existing European isolates. The majority of isolates represent genotypes previously described in Europe although novel genotypes were identified in both B. ceti clades. Harp seals were found to carry B. pinnipedialis genotypes previously confined to hooded seals among a diverse repertoire of sequence types (STs) associated with this species. For the first time Brucella isolates were characterised from beluga whales and found to represent a number of distinct B. pinnipedialis genotypes. In addition the known host range of ST27 was extended with the identification of this ST from California sea lion samples. Finally the performance of the frequently used diagnostic tool Bruce-ladder, in differentiating B. ceti and B. pinnipedialis, was critically assessed based on improved knowledge of the global population structure of Brucella associated with marine mammals.

  2. Mineral chemistry of magnetite from magnetite-apatite mineralization and their host rocks: examples from Kiruna, Sweden, and El Laco, Chile

    Science.gov (United States)

    Broughm, Shannon G.; Hanchar, John M.; Tornos, Fernando; Westhues, Anne; Attersley, Samuel

    2017-12-01

    Interpretation of the mineralizing environment of magnetite-apatite deposits remains controversial with theories that include a hydrothermal or magmatic origin or a combination of those two processes. To address this controversy, we have analyzed the trace element content of magnetite from precisely known geographic locations and geologic environments from the Precambrian magnetite-apatite ore and host rocks in Kiruna, Sweden, and the Pliocene-Holocene El Laco volcano in the Atacama desert of Chile. Magnetite samples from Kiruna have low trace element concentrations with little chemical variation between the ore, host, and related intrusive rocks. Magnetite from andesite at El Laco, and dacite from the nearby Láscar volcano, has high trace element concentrations typical of magmatic magnetite. El Laco ore magnetite have low trace element concentrations and displays growth zoning in incompatible elements (Si, Ca, and Ce), compatible elements (Mg, Al, and Mn), large-ion lithophile element (Sr), and high field strength element (Y, Nb, and Th). The El Laco ore magnetite are similar in composition to magnetite that has been previously interpreted to have crystallized from hydrothermal fluids; however, there is a significant difference in the internal zoning patterns. At El Laco, each zoned element is either enriched or depleted in the same layers, suggesting the magnetite crystallized from a volatile-rich, iron-oxide melt. In general, the compositions of magnetite from these two deposits plot in very wide fields that are not restricted to the proposed fields in published discriminant diagrams. This suggests that the use of these diagrams and genetic models based on them should be used with caution.

  3. Characteristics of a Low-Sulfidation Epithermal Deposit in the River Reef Zone and the Watuputih Hill, the Poboya Gold Prospect, Central Sulawesi, Indonesia: Host Rocks and Hydrothermal Alteration

    Directory of Open Access Journals (Sweden)

    Syafrizal

    2017-07-01

    Full Text Available Systematic exploration has delineated significant gold mineralization in the River Reef Zone and the presence of a siliceous body at Watuputih Hill, which is a Poboya gold prospect in Central Sulawesi, Indonesia. The mineralization is hosted within the Palu Metamorphic Complex. The host rocks consist of granite, biotite gneiss, and biotite schist, which is intercalated by feldspar porphyroblastic biotite schist and amphibolitic schist. The X-ray fluorescence (XRF analysis of the granite and biotite gneiss suggests that the granitic rocks can be characterized as magnesian arc calc-alkaline rocks, with a weakly peraluminous composition. Alteration minerals were analyzed by a combination of petrographic and X-ray diffraction (XRD. In the River Reef Zone, the hydrothermal alteration zones can be sorted by their proximity to the primary fluid conduit and divided into inner, high-T, and low-T propylitic zones. In Watuputih Hill, the hydrothermal alteration can be divided into advanced argillic and argillic zones. The hydrothermal alteration assemblages indicated that the fluid was at a near-neutral pH in the River Reef Zone, whereas the fluid was acidic within Watuputih Hill. Because the hill is relatively distant from the River Reef Zone, the presence of these zones at Watuputih Hill may be indicative of another mineralization system beneath the hill.

  4. Characterisation of bacterial brown spot pathogen from dry bean ...

    African Journals Online (AJOL)

    Pseudomonas syringae pv. syringae (Pss) causes bacterial brown spot (BBS) of beans (Phaseolus vulgaris L.), with yield losses of up to 55% in South Africa. Pss has a wide host range and for many of these, the pathogen has been biochemically and genetically characterised. However, few studies have been conducted on ...

  5. Experiments on thermo-hydro-mechanical behaviour of Opalinus Clay at Mont Terri rock laboratory, Switzerland

    Directory of Open Access Journals (Sweden)

    Paul Bossart

    2017-06-01

    Full Text Available Repositories for deep geological disposal of radioactive waste rely on multi-barrier systems to isolate waste from the biosphere. A multi-barrier system typically comprises the natural geological barrier provided by the repository host rock – in our case the Opalinus Clay – and an engineered barrier system (EBS. The Swiss repository concept for spent fuel and vitrified high-level waste (HLW consists of waste canisters, which are emplaced horizontally in the middle of an emplacement gallery and are separated from the gallery wall by granular backfill material (GBM. We describe here a selection of five in-situ experiments where characteristic hydro-mechanical (HM and thermo-hydro-mechanical (THM processes have been observed. The first example is a coupled HM and mine-by test where the evolution of the excavation damaged zone (EDZ was monitored around a gallery in the Opalinus Clay (ED-B experiment. Measurements of pore-water pressures and convergences due to stress redistribution during excavation highlighted the HM behaviour. The same measurements were subsequently carried out in a heater test (HE-D where we were able to characterise the Opalinus Clay in terms of its THM behaviour. These yielded detailed data to better understand the THM behaviours of the granular backfill and the natural host rock. For a presentation of the Swiss concept for HLW storage, we designed three demonstration experiments that were subsequently implemented in the Mont Terri rock laboratory: (1 the engineered barrier (EB experiment, (2 the in-situ heater test on key-THM processes and parameters (HE-E experiment, and (3 the full-scale emplacement (FE experiment. The first demonstration experiment has been dismantled, but the last two ones are on-going.

  6. GRS' research on clay rock in the Mont Terri underground laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Wieczorek, Klaus; Czaikowski, Oliver [Gesellschaft fuer Anlagen- und Reaktorsicherheit gGmbH, Braunschweig (Germany)

    2016-07-15

    For constructing a nuclear waste repository and for ensuring the safety requirements are met over very long time periods, thorough knowledge about the safety-relevant processes occurring in the coupled system of waste containers, engineered barriers, and the host rock is indispensable. For respectively targeted research work, the Mont Terri rock laboratory is a unique facility where repository research is performed in a clay rock environment. It is run by 16 international partners, and a great variety of questions are investigated. Some of the work which GRS as one of the Mont Terri partners is involved in is presented in this article. The focus is on thermal, hydraulic and mechanical behaviour of host rock and/or engineered barriers.

  7. Seismic response of rock joints and jointed rock mass

    International Nuclear Information System (INIS)

    Ghosh, A.; Hsiung, S.M.; Chowdhury, A.H.

    1996-06-01

    Long-term stability of emplacement drifts and potential near-field fluid flow resulting from coupled effects are among the concerns for safe disposal of high-level nuclear waste (HLW). A number of factors can induce drift instability or change the near-field flow patterns. Repetitive seismic loads from earthquakes and thermal loads generated by the decay of emplaced waste are two significant factors. One of two key technical uncertainties (KTU) that can potentially pose a high risk of noncompliance with the performance objectives of 10 CFR Part 60 is the prediction of thermal-mechanical (including repetitive seismic load) effects on stability of emplacement drifts and the engineered barrier system. The second KTU of concern is the prediction of thermal-mechanical-hydrological (including repetitive seismic load) effects on the host rock surrounding the engineered barrier system. The Rock Mechanics research project being conducted at the Center for Nuclear Waste Regulatory Analyses (CNWRA) is intended to address certain specific technical issues associated with these two KTUs. This research project has two major components: (i) seismic response of rock joints and a jointed rock mass and (ii) coupled thermal-mechanical-hydrological (TMH) response of a jointed rock mass surrounding the engineered barrier system (EBS). This final report summarizes the research activities concerned with the repetitive seismic load aspect of both these KTUs

  8. FEBEX Full-Scalle Engineered barriers experiment in crystalline host rock Preoperational thermo-hydro-mechanical (THM) modelling of the in situ test

    International Nuclear Information System (INIS)

    1998-01-01

    This report contains the results of a set of 1-D and 2-D coupled thermo-hydro-mechanical (THM) analyses carried out during the preoperational stage simulating the in situ FEBEX test. The analyses incorporate available information concerning rock and bentonite properties as well as the final test layout and conditions. The main goals are: -To provide the best estimate of test performance given current models and information - To define a basis for future model improvements. The theoretical bases of the analyses and the computer code used are reviewed. Special reference is made to the process of parameter estimation that tries to incorporate available information on material behaviour obtained in the characterisation work carried out both in the laboratory and in the field. Data obtained in the characterisation stage is also used to define initial and boundary conditions. The results of the 1-D THM Base Case analysis are used to gain a good understanding of expected test behaviour concerning thermal, hydraulic and mechanical problems. A quite extensive programme of sensitivity analyses is also reported in which the effect of a number of parameters and boundary conditions are examined. The results of the sensitivity analyses place an appropriate context the information obtained from the Base Case showing, for instance, that rock desaturation and degree of buffer hydration depend on some critical parameters in a complex way. Two-dimensional effects are discussed on the basis of the results of 2-D axisymmetric THM analysis performed using a longitudinal section that provides a better representation of real test geometry. Quantitative but not qualitative differences are found with respect to the 1-D results. Finally, a 2-D THM cross section analysis has been performed under plane strain conditions. No specific 2-D effects are observed in this case as quasi-axisymmetric conditions have been prescribed. The models employed in the analyses included in this report have not

  9. Investigation on the anisotropic mechanical behaviour of the Callovo-Oxfordian clay rock within the framework of ANDRA/GRS cooperation programme. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chun-Liang [Gesellschaft fuer Anlagen- und Reaktorsicherheit mbH (GRS), Koeln (Germany); Armand, Gilles; Conil, Nathalie [French Agence Nationale Pour la Gestion de Dechets Radioactifs (ANDRA), Chatenay-Malabry (France)

    2015-01-15

    An underground repository for disposal of radioactive waste is planned to be constructed in the sedimentary Callovo-Oxfordian argillaceous formation (COX) in France /AND 05/. The clay rock exhibits inherent anisotropy with bedding structure, which leads to directional dependences of the rock properties (e.g. mineralogical, physical, mechanical, hydraulic, thermal, etc.) with respect to the bedding planes. For the design of the repository and the assessment of its safety during the operation and post-closure phases it is necessary to characterise and predict the anisotropic properties and processes in the host rock, particularly in the excavation damaged zone (EDZ) near the openings. Within the framework of the bilateral cooperation agreement between the French National Radioactive Waste Management Agency (ANDRA) and the German Federal Ministry of Economics and Technology (BMWi), concerning the research activities in the Meuse/Haute-Marne Underground Research Laboratory (MHM-URL), a joint research programme was initiated by ANDRA and GRS in 2013 to investigate mechanical anisotropy of the COX clay rock for the purpose of precise characterization, better understanding and reliable prediction of the development of EDZ around the repository. This programme was funded by ANDRA under contract number 059844 and performed by GRS during the time period of November 2013 to December 2014. GRS gratefully acknowledges the financial support from and the fruitful cooperation with ANDRA.

  10. Metamorphic Rock-Hosted Orogenic Gold Deposit Type as a Source of Langkowala Placer Gold, Bombana, Southeast Sulawesi

    Directory of Open Access Journals (Sweden)

    Arifudin Idrus

    2014-06-01

    Full Text Available DOI: 10.17014/ijog.v6i1.114In 2008, placer gold was discovered in Langkowala area (Bombana Regency, Southeast Sulawesi, Indonesia, and more than 60,000 traditional gold miners in the early 2009 have been operating by digging vertical pits and panning active stream sediments. The grade of placer gold ranges from 50 to 140 g/t. Local geological framework indicates that the placer gold is not related to volcanic rock-related hydrothermal gold deposit, e.g. epithermal, skarn or porphyry. This paper describes a preliminary study on possible primary deposit type as a source of the Langkowala (Bombana secondary placer gold. A field study indicates that the Langkowala (Bombana placer/paleoplacer gold is possibly related to gold-bearing quartz veins/veinlets hosted by metamorphic rocks particularly mica schist and metasediments in the area. These quartz veins/veinlets are currently recognized in metamorphic rocks at Wumbubangka Mountains, a northern flank of Rumbia Mountain Range. Sheared, segmented quartz veins/veinlets are of 2 cm to 2 m in width and contain gold in a grade varying between 2 and 61 g/t. At least, there are two generations of the quartz veins. The first generation of quartz vein is parallel to foliation of mica schist and metasediments with general orientation of N 300oE/60o; the second quartz vein generation crosscut the first quartz vein and the foliation of the wallrock. The first quartz veins are mostly sheared/deformed, brecciated, and occasionally sigmoidal, whereas the second quartz veins are relatively massive. The similar quartz veins/veinlets types are also probably present in Mendoke Mountain Range, in the northern side of Langkowala area. This primary gold deposit is called as ‘orogenic gold type’. The orogenic gold deposit could be a new target of gold exploration in Indonesia in the future.

  11. ONKALO rock mechanics model (RMM) - Version 2.0

    International Nuclear Information System (INIS)

    Moenkkoenen, H.; Hakala, M.; Paananen, M.; Laine, E.

    2012-02-01

    The Rock Mechanics Model of the ONKALO rock volume is a description of the significant features and parameters related to rock mechanics. The main objective is to develop a tool to predict the rock properties, quality and hence the potential for stress failure which can then be used for continuing design of the ONKALO and the repository. This is the second implementation of the Rock Mechanics Model and it includes sub-models of the intact rock strength, in situ stress, thermal properties, rock mass quality and properties of the brittle deformation zones. Because of the varying quantities of available data for the different parameters, the types of presentations also vary: some data sets can be presented in the style of a 3D block model but, in other cases, a single distribution represents the whole rock volume hosting the ONKALO. (orig.)

  12. Economic potential of the Rooiberg Group: volcanic rocks in the floor and roof of the Bushveld Complex

    Science.gov (United States)

    Schweitzer, J. K.; Hatton, C. J.; de Waal, S. A.

    1995-04-01

    Volcanic rocks of the Rooiberg Group are preserved in the floor and roof of the mafic Rustenburg Layered Suite of the Bushveld Complex. Field and geochemical characteristics of these volcanic rocks imply that they are genetically related to the Rustenburg Layered Suite. Four major ore-forming events are identified in the Rooiberg Group. The first phase was accompanied by volcanic hosted, fault controlled, hydrothermal copper mineralisation, which is found in the lowermost portion of the Rooiberg Group, underlying the Rustenburg Layered Suite. This type of mineralisation is tentatively linked to initial Rustenburg Layered Suite intrusions. Stratabound arsenic mineralisation that possibly formed in response to contact metamorphism, characterises the second phase, and occurred after extrusion of the Damwal Formation, possibly due to shallow granophyric intrusion. The third mineralising event occurred in response to contact metamorphism during the final stages of the Rustenburg Layered Suite, where especially Pb and Zn were introduced into the felsite roof rocks. This type of mineralisation affected the majority of the Rooiberg Group, but is most pronounced towards the contact with the Rustenburg Layered Suite. The fourth phase is restricted to the Rooiberg Group in the Nylstroom area and is linked to the granite intrusions of the Lebowa Granite Suite, from which Sn and F were introduced into the uppermost felsite succession. Mineralisation in the Rooiberg Group appears to be controlled by the character and intrusion level of the associated Bushveld magmas. Different styles of mineralisation in Rooiberg Group volcanic rocks are encountered at various stratigraphic levels. Major primary volcanogenic ore deposits appear to be absent.

  13. Characterisation of North American Brucella isolates from marine mammals.

    Directory of Open Access Journals (Sweden)

    Adrian M Whatmore

    Full Text Available Extension of known ecological niches of Brucella has included the description of two novel species from marine mammals. Brucella pinnipedialis is associated predominantly with seals, while two major Brucella ceti clades, most commonly associated with porpoises or dolphins respectively, have been identified. To date there has been limited characterisation of Brucella isolates obtained from marine mammals outside Northern European waters, including North American waters. To address this gap, and extend knowledge of the global population structure and host associations of these Brucella species, 61 isolates from marine mammals inhabiting North American waters were subject to molecular and phenotypic characterisation enabling comparison with existing European isolates. The majority of isolates represent genotypes previously described in Europe although novel genotypes were identified in both B. ceti clades. Harp seals were found to carry B. pinnipedialis genotypes previously confined to hooded seals among a diverse repertoire of sequence types (STs associated with this species. For the first time Brucella isolates were characterised from beluga whales and found to represent a number of distinct B. pinnipedialis genotypes. In addition the known host range of ST27 was extended with the identification of this ST from California sea lion samples. Finally the performance of the frequently used diagnostic tool Bruce-ladder, in differentiating B. ceti and B. pinnipedialis, was critically assessed based on improved knowledge of the global population structure of Brucella associated with marine mammals.

  14. Feedback from performance assessment to site characterisation. The SITE-94 example

    International Nuclear Information System (INIS)

    Dverstorp, B.; Geier, J.

    1999-01-01

    Interaction and information exchange between site characterisation and performance assessment are key features of any successful radioactive waste management programme. Some examples are presented of the types of feedback that can be offered from performance assessment to site characterisation, based on SKI's most recent performance assessment project, SITE-94. SITE-94 in Sweden was an assessment of a hypothetical repository for spent nuclear fuel, based on real data gathered in the surface-based investigation of the Aespoe Hard Rock Laboratory site. Examples of feedback are given concerning quality control of data and site investigation procedures, identification of key parameters for the performance assessment, use of models for planning and evaluation of a site investigation, data sampling strategies, and guidance on future priorities for further development of site investigation methods. Because site characterisation serves multiple purposes, including provision of data for repository design and construction, it must account for and compromise among requirements from several lines of analyses in the performance assessment. (author)

  15. False colour backscatter electron images and their application during electron microprobe analysis of ores and host rocks

    International Nuclear Information System (INIS)

    Cousens, D.R.; French, D.H.; Ramsden, A.R.

    1989-01-01

    The limited contrast range of conventional black and white imaging does not enable full use to be made of the dynamic range of the video signal obtained from a scanning electron microscope or microprobe. The use of false colour substantially increases the information that can be derived from such images enabling relationships to be displayed that cannot be observed in black and white. This capability is now used extensively in combination with quantitative electron microprobe analysis as a research tool for ore characterization and host rocks studies related to minerals exploration in the CSIRO Div.sion of Exploration Geoscience. Thus the CAMEBAX scanning electron microprobe has been modified to allow digital images acquisition and software (IMAGE) developed which allows false colour backscatter electron (BSE) images to be obtained during the course of routine electron microprobe analysis. 1 fig

  16. Evaluation of Five Sedimentary Rocks Other Than Salt for Geologic Repository Siting Purposes

    Energy Technology Data Exchange (ETDEWEB)

    Croff, A.G.; Lomenick, T.F.; Lowrie, R.S.; Stow, S.H.

    2003-11-15

    The US Department of Energy (DOE), in order to increase the diversity of rock types under consideration by the geologic disposal program, initiated the Sedimary ROck Program (SERP), whose immediate objectiv eis to evaluate five types of secimdnary rock - sandstone, chalk, carbonate rocks (limestone and dolostone), anhydrock, and shale - to determine the potential for siting a geologic repository. The evaluation of these five rock types, together with the ongoing salt studies, effectively results in the consideration of all types of relatively impermeable sedimentary rock for repository purposes. The results of this evaluation are expressed in terms of a ranking of the five rock types with respect to their potential to serve as a geologic repository host rock. This comparative evaluation was conducted on a non-site-specific basis, by use of generic information together with rock evaluation criteria (RECs) derived from the DOE siting guidelines for geologic repositories (CFR 1984). An information base relevant to rock evaluation using these RECs was developed in hydrology, geochemistry, rock characteristics (rock occurrences, thermal response, rock mechanics), natural resources, and rock dissolution. Evaluation against postclosure and preclosure RECs yielded a ranking of the five subject rocks with respect to their potential as repository host rocks. Shale was determined to be the most preferred of the five rock types, with sandstone a distant second, the carbonate rocks and anhydrock a more distant third, and chalk a relatively close fourth.

  17. Evaluation of Five Sedimentary Rocks Other Than Salt for Geologic Repository Siting Purposes

    International Nuclear Information System (INIS)

    Croff, A.G.; Lomenick, T.F.; Lowrie, R.S.; Stow, S.H.

    2003-01-01

    The US Department of Energy (DOE), in order to increase the diversity of rock types under consideration by the geologic disposal program, initiated the Sedimary ROck Program (SERP), whose immediate objectiv eis to evaluate five types of secimdnary rock - sandstone, chalk, carbonate rocks (limestone and dolostone), anhydrock, and shale - to determine the potential for siting a geologic repository. The evaluation of these five rock types, together with the ongoing salt studies, effectively results in the consideration of all types of relatively impermeable sedimentary rock for repository purposes. The results of this evaluation are expressed in terms of a ranking of the five rock types with respect to their potential to serve as a geologic repository host rock. This comparative evaluation was conducted on a non-site-specific basis, by use of generic information together with rock evaluation criteria (RECs) derived from the DOE siting guidelines for geologic repositories (CFR 1984). An information base relevant to rock evaluation using these RECs was developed in hydrology, geochemistry, rock characteristics (rock occurrences, thermal response, rock mechanics), natural resources, and rock dissolution. Evaluation against postclosure and preclosure RECs yielded a ranking of the five subject rocks with respect to their potential as repository host rocks. Shale was determined to be the most preferred of the five rock types, with sandstone a distant second, the carbonate rocks and anhydrock a more distant third, and chalk a relatively close fourth.

  18. Natural analogue studies in crystalline rock: the influence of water-bearing fractures on radionuclide immobilisation in a granitic rock repository

    International Nuclear Information System (INIS)

    Alexander, W.R.; MacKenzie, A.B.; Scott, R.D.; McKinley, I.G.

    1990-06-01

    Current Swiss concepts for the disposal of radioactive waste involve disposal in deep mined repositories to ensure that only insignificant quantities of radionuclides will ever reach the surface and so enter the biosphere. The rock formations presently considered as potential candidates for hosting radwaste repositories have thus been selected on the basis of their capacity to isolate radionuclides from the biosphere. An important factor in ensuring such containment is a very low solute transport rate through the host formation. However, it is considered likely that, in the formations of interest in the Swiss programme (eg. granites, argillaceous sediments, anhydrite), the rocks will be fractured to some extent even at repository depth. In the instance of the cumulative failure of near-field barriers in the repository, these hydraulically connected fractures in the host formation could be very important far-field routes of migration (and possible sites of retardation) of radionuclides dissolved in the groundwaters. In this context, the so-called 'matrix diffusion' mechanism is potentially very important for radionuclide retardation. This report is the culmination of a programme which has attempted to assess the potential influence of these water-bearing fractures on radionuclide transport in a crystalline rock radwaste repository. 162 refs., 36 figs., 16 tabs

  19. GRAPHITIZATION OF METASEDIMENTARY ROCKS IN THE WESTERN KONYA

    Directory of Open Access Journals (Sweden)

    Hüseyin KURT

    2000-01-01

    Full Text Available The Paleozoic-Mesozoic metasedimentary rocks in the study area are metacarbonate, metachert, metapelite, metasandstone and metaconglomerate. Graphite layers are 1cm to 2m thick, extend laterally for tens of meters and are intercalated with metasedimentary rocks. Generally, the graphite is black in color, with a well developed cleavage which is concordant with the cleavage of the host rocks. In addition, the crystal and flake graphites formed in metasedimentary rocks are mostly aligned parallel to the cleavage planes. These metamorphic rocks are subjected to shearing and granulation providing structural control for the development of graphite. It was probably this phenomenon that first led to emphasize the relationship between graphite and metasedimentary rocks. Graphite mineralization has been controlled by bedding, microfractures and granulations. Briefly, the metamorphism has converted carbonaceous matter into graphite .

  20. The effect of extent of site investigation on the estimation of radiological performance and its relevance to the proposed Rock Characterisation Facility at Sellafield

    International Nuclear Information System (INIS)

    Mackay, R.

    1996-01-01

    Proof of Evidence is given by an expert witness on behalf of Greenpeace Ltd as part of their submission to a Planning Inquiry in 1995 hearing the application of UK Nirex Ltd for permission to construct an underground Rock Characterisation Facility (RCF) at a site near Sellafield. The RCF is part of an investigation by Nirex into a suitable site for the disposal of radioactive waste. The evidence concerns the necessity of establishing an adequate hydrogeological model of the site in advance of the construction of the RCF in order to estimate its radiological performance. This detailed examination of Nirex's approach concludes that it is not apparent that a method for demonstrating the adequacy of the conceptual hydrogeological model has been clearly and openly stated so that it may be agreed in advance of construction with an appropriate authority. (1 figure; 1 table, 12 references). (UK)

  1. Some Key Features and Possible Origin of the Metamorphic Rock-Hosted Gold Mineralization in Buru Island, Indonesia

    Directory of Open Access Journals (Sweden)

    Arifudin Idrus

    2014-07-01

    Full Text Available DOI: 10.17014/ijog.v1i1.172This paper discusses characteristics of some key features of the primary Buru gold deposit as a tool for a better understanding of the deposit genesis. Currently, about 105,000 artisanal and small-scale gold miners (ASGM are operating in two main localities, i.e. Gogorea and Gunung Botak by digging pits/shafts following gold-bearing quartz vein orientation. The gold extraction uses mercury (amalgamation and cyanide processing. The field study identifies two types/generations of quartz veins namely (1 Early quartz veins which are segmented, sigmoidal, dis­continous, and parallel to the foliation of host rock. The quartz vein is lack of sulfides, weak mineralized, crystalline, relatively clear, and maybe poor in gold, and (2 Quartz veins occurred within a ‘mineralized zone’ of about 100 m in width and ~1,000 m in length. The gold mineralization is strongly overprinted by an argillic alteration zone. The mineralization-alteration zone is probably parallel to the mica schist foliation and strongly controlled by N-S or NE-SW-trending structures. The gold-bearing quartz veins are characterized by banded texture particularly colloform following host rock foliation and sulphide banding, brecciated, and rare bladed-like texture. The alteration types consist of propylitic (chlorite, calcite, sericite, argillic, and carbonation represented by graphite banding and carbon flakes. The ore mineralization is characterized by pyrite, native gold, pyrrhotite, and arsenopyrite. Cinnabar, stibnite, chalcopyrite, galena, and sphalerite are rare or maybe absent. In general, sulphide minerals are rare (<3%. Fifteen rock samples were collected in Wamsaid area for geochemical assaying for Au, Ag, As, Sb, Hg, Cu, Pb, and Zn. Eleven of fifteen samples yielded more than 1.00 g/t Au, in which six of them are in excess of 3.00 g/t Au. It can be noted that all high-grade samples are originally or containing limonitic materials, that suggest

  2. Experimental thermomechanical damage as first approach to understand the petrophysical behavior of the granitic host-rocks from an active fractured-geothermal system (Liquiñe, Chile - 39º S)

    Science.gov (United States)

    Molina Piernas, E.; Sepúlveda, J.; Arancibia, G.; Roquer, T.; Morata, D.; Bracke, R.; Vázquez, P.

    2017-12-01

    Chile's location along an active subduction zone has endowed it with a high geothermal potential. However, a better understanding of the thermomechanical and fluid transport properties of rocks is required to assess the potential of geothermal systems and thereby enhance the possibilities for their use. We have focused in the area surrounding Liquiñe, in the Southern Andean Volcanic Zone (Chile, 39º S). This area hosts several recent thermal manifestations, predominantly hot springs, and it is affected by the Liquiñe-Ofqui Fault Zone (LOFZ), which controls the position of the modern volcanic arc in southern Chile and cuts the Patagonian batholith. We have carried out experimental analyzes in order to understand this geothermal system and the influence of the thermomechanical features over the granitic host-rocks (low-porous crystalline rocks). To do this, physical properties such as capillary water absorption coefficient, Vp-wave velocity and compressive resistance were evaluated before and after heating rock samples at 150 ºC and 210 ºC (at ambient pressure) in an oven at a heating rate of 6 °C/min and maintaining the maximum temperature for 4 hours. The cooling rate was less than 2 °C/min to avoid shrinkage phenomena. The results show that the damage by heat was greater at 210 ºC than 150 ºC, likely due to an increased capillary coefficient ( 30% and 25%). On the contrary, Vpvelocity ( -19% and -13%) and compressive resistance ( -27% in both cases) decreased, with respect to unheated samples. Consequently, we can infer an inherent effect on the later fracture process due to the thermal stress when this granitic body was at depth. After that, and considering the local and regional strain-stress state, both factors have facilitated the fluid flow, increasing the permeability of this granitic host-rock allowing the presence of hot-springs. Future work will be to acquire complementary petrophysical parameters, such as porosity, permeability, thermal

  3. Characterization and evaluation of sites for deep geological disposal of radioactive waste in fractured rocks. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    The third Aespoe International Seminar was organised by SKB to assess the state of the art in characterisation and evaluation of sites for deep geological disposal of radioactive waste in fractured rocks. Site characterisation and evaluation are important elements for determining the site suitability and long-term safety of a geological repository for radioactive waste disposal. Characterisation work also provides vital information for the design of the underground facility and the engineered barrier system that will contain the waste. The aim of the seminar was to provide a comprehensive assessment of the current know-how on this topic based on world-wide experience from more than 20 years of characterisation and evaluation work. The seminar, which was held at the Aespoe Hard Rock Laboratory was attended by 72 scientists from 10 different countries. The program was divided into four sessions of which two were run in parallel. A total of 38 oral and 5 poster presentations were given at the seminar. The presentations gave a comprehensive summary of recently completed and current work on site characterisation, modelling and application in performance assessments. The results presented at the seminar generally show that significant progress has been made in this field during the last decade. New characterisation techniques have become available, strategies for site investigations have developed further, and model concepts and codes have reached new levels of refinement. Data obtained from site characterisation have also successfully been applied in several site specific performance assessments. The seminar clearly showed that there is a solid scientific basis for assessing the suitability of sites for actual repositories based on currently available site characterisation technology and modelling capabilities. Separate abstracts have been prepared for 38 of the presentations

  4. Aqueous Alteration of Endeavour Crater Rim Apron Rocks

    Science.gov (United States)

    Ming, D. W.; Mittlefehldt, D. W.; Gellert, R.; Clark, B. C.; Morris, R. V.; Yen, A. S.; Arvidson, R. E.; Crumpler, L. S.; Farrand, W. H.; Grant, J. A., III; Jolliff, B. L.; Parker, T. J.; Peretyazhko, T.

    2014-12-01

    Mars Exploration Rover Opportunity is exploring Noachian age rocks of the rim of 22 km diameter Endeavour crater. Overlying the pre-impact lithologies and rim breccias is a thin apron of fine-grained sediments, the Grasberg fm, forming annuli on the lower slopes of rim segments. Hesperian Burns fm sandstones overly the Grasberg fm. Grasberg rocks have major element compositions that are distinct from Burns fm sandstones, especially when comparing interior compositions exposed by the Rock Abrasion Tool. Grasberg rocks are also different from Endeavour rim breccias, but have general compositional similarities to them. Grasberg sediments are plausibly fine-grained materials derived from the impact breccias. Veins of CaSO4 transect Grasberg fm rocks demonstrating post-formation aqueous alteration. Minor/trace elements show variations consistent with mobilization by aqueous fluids. Grasberg fm rocks have low Mn and high Fe/Mn ratios compared to the other lithologies. Manganese likely was mobilized and removed from the Grasberg host rock by redox reactions. We posit that Fe2+ from acidic solutions associated with formation of the Burns sulfate-rich sandstones acted as an electron donor to reduce more oxidized Mn to Mn2+. The Fe contents of Grasberg rocks are slightly higher than in other rocks suggesting precipitation of Fe phases in Grasberg materials. Pancam spectra show that Grasberg rocks have a higher fraction of ferric oxide minerals than other Endeavour rim rocks. Solutions transported Mn2+ into the Endeavour rim materials and oxidized and/or precipitated it in them. Grasberg has higher contents of the mobile elements K, Zn, Cl, and Br compared to the rim materials. Similar enrichments of mobile elements were measured by the Spirit APXS on West Spur and around Home Plate in Gusev crater. Enhancements in these elements are attributed to interactions of hydrothermal acidic fluids with the host rocks. Interactions of fluids with the Grasberg fm postdate the genesis

  5. Chemical characterisation of himalayan rock salt

    International Nuclear Information System (INIS)

    Hassan, A.U.; Din, M.U.

    2017-01-01

    Present study involves the chemical evaluation of rock salt samples collected from the plugging sites of Himalayan salt (Khewra salt mines and Kalabagh salt mines) for their moisture content, water insoluble matter, calcium, magnesium, sulphate content and trace minerals such as Fe,Cu,Cd,Pb,As,Ag and Zn determined by atomic absorption spectroscopy. Moisture content of Khewra and Kalabagh salt samples ranged from 0.03 wt. % to 0.09 wt. % and 0.06 % to 0.08 %, respectively. Water insoluble matter ranged from 0.08 wt. % to 1.4 wt. % and 1.5 wt. % to 2.8wt. % for Khewra and Kalabagh salt samples, respectively. Sulphate content for Khewra salt sample was from 0.39 % to 0.91 % and for Kalabagh salt mines from 0.75 wt. % to 0.95 wt. %. For Khewra salt mines calcium ranged 0.15 wt. % to 0.32 wt. % and for Kalabagh salt samples from 0.1 wt. % to 0.27 wt. %. Magnesium ranged from 0.11 wt. % to 0.35 wt. % for Khewra salt mines, while for Kalabagh salt samples its range was 0.18 wt. % to 0.89 wt. %. Trace metals had the concentration ranges between 0.2 to 1.85 mg/kg for copper; between 0.21 to 0.42 mg/kg for manganese; between 0.04 to 0.06 mg/kg for zinc; between 0.12 to 0.18 mg/kg for arsenic and between 0.03 and 0.05 mg/kg for lead while cadmium content was either below the method's detection limits or in very trace amounts. The results show that the concentrations of all the parameters studied are below the limits set by World Health Organization (WHO) and Food and Agriculture Organization (FAO). Therefore, it can be concluded from the paper that the Himalayan salt from the plugging sites of Khewra and Kalabagh salt mines are safe to use. (author)

  6. Nature of parent rocks, mineralization styles and ore genesis of regolith-hosted REE deposits in South China: An integrated genetic model

    Science.gov (United States)

    Li, Yan Hei Martin; Zhao, Wen Winston; Zhou, Mei-Fu

    2017-10-01

    Regolith-hosted rare earth element (REE) deposits, also called ion-adsorption or weathered crust elution-deposited REE deposits are distributed over Jiangxi, Guangdong, Fujian, Hunan, Guangxi and Yunnan provinces in South China. In general, these deposits can be categorized into the HREE-dominated type, for example the famous Zudong deposit in southern Jiangxi province and the LREE-dominated type, such as the Heling and Dingnan deposits in southern Jiangxi province. Most of these deposits form from weathering of biotite and muscovite granites, syenites, monzogranites, granodiorites, granite porphyries, and rhyolitic tuffs. The parent rocks are generally peraluminous, siliceous, alkaline and contain a variety of REE-bearing minerals. Mostly, REE patterns of regolith are inherited from the parent rocks, and therefore, characteristics of the parent rocks impose a significant control on the ore formation. Data compilation shows that autometasomatism during the latest stage of granite crystallization is likely essential in forming the HREE-enriched granites, whereas LREE-enriched granites could form through magmatic differentiation. These deposits are normally two- to three-fold, but could be up to ten-fold enrichment in REE compared to the parent granites, where the maximum enrichment usually occurs from the lower B to the upper C horizon. Ce shows different behavior with the other REEs. Strongly positive Ce anomalies commonly occur at the upper part of weathering profiles, likely due to oxidation of Ce3+ to Ce4+ and removal of Ce from soil solutions through precipitation of cerianite. Vertical pH and redox gradients in weathering crusts facilitate dissolution of REE-bearing minerals at shallow level and fixation of REE at depth through either adsorption on clay minerals or precipitation of secondary minerals. At the same time, mass removal of major elements plays an important role in concentrating REE in regolith. Combination of mass removal and eluviation

  7. Research on geochronology and uranium source of sandstone-hosted uranium ore-formation in major uranium-productive basins, Northern-China

    International Nuclear Information System (INIS)

    Xia Yuliang; Liu Hanbin; Lin Jinrong; Fan Guang; Hou Yanxian

    2004-12-01

    A method is developed for correcting uranium content in uranium ore samples by considering the U-Ra equilibrium coefficient, then a U-Pb isochron is drawn up. By performing the above correction ore-formation ages of sandstone-hosted uranium mineralization which may be more realistic have been obtained. The comparative research on U-Pb isotopic ages of detritic zircon in ore-hosting sandstone and zircon in intermediate-acid igneous rocks in corresponding provenance area indicates that the ore-hosting sandstone is originated from the erosion of intermediate-acid igneous rocks and the latters are the material basis for the formation of the uranium-rich sandstone beds. On the basis of the study on U-Pb isotopic system evolution of the provenance rocks and sandstones from ore-hosting series, it is verified that the uranium sources of the sandstone-hosted uranium deposit are: the intermediate-acid igneous rocks with high content of mobile uranium, and the sandstone bodies pre-concentrated uranium. (authors)

  8. Incorporating the Impacts of Small Scale Rock Heterogeneity into Models of Flow and Trapping in Target UK CO2 Storage Systems

    Science.gov (United States)

    Jackson, S. J.; Reynolds, C.; Krevor, S. C.

    2017-12-01

    Predictions of the flow behaviour and storage capacity of CO2 in subsurface reservoirs are dependent on accurate modelling of multiphase flow and trapping. A number of studies have shown that small scale rock heterogeneities have a significant impact on CO2flow propagating to larger scales. The need to simulate flow in heterogeneous reservoir systems has led to the development of numerical upscaling techniques which are widely used in industry. Less well understood, however, is the best approach for incorporating laboratory characterisations of small scale heterogeneities into models. At small scales, heterogeneity in the capillary pressure characteristic function becomes significant. We present a digital rock workflow that combines core flood experiments with numerical simulations to characterise sub-core scale capillary pressure heterogeneities within rock cores from several target UK storage reservoirs - the Bunter, Captain and Ormskirk sandstone formations. Measured intrinsic properties (permeability, capillary pressure, relative permeability) and 3D saturations maps from steady-state core flood experiments were the primary inputs to construct a 3D digital rock model in CMG IMEX. We used vertical end-point scaling to iteratively update the voxel by voxel capillary pressure curves from the average MICP curve; with each iteration more closely predicting the experimental saturations and pressure drops. Once characterised, the digital rock cores were used to predict equivalent flow functions, such as relative permeability and residual trapping, across the range of flow conditions estimated to prevail in the CO2 storage reservoirs. In the case of the Captain sandstone, rock cores were characterised across an entire 100m vertical transect of the reservoir. This allowed analysis of the upscaled impact of small scale heterogeneity on flow and trapping. Figure 1 shows the varying degree to which heterogeneity impacted flow depending on the capillary number in the

  9. Tectonic constraints on a deep-seated rock slide in weathered crystalline rocks

    Science.gov (United States)

    Borrelli, Luigi; Gullà, Giovanni

    2017-08-01

    Deep-seated rock slides (DSRSs), recognised as one of the most important mass wasting processes worldwide, involve large areas and cause several consequences in terms of environmental and economic damage; they result from a complex of controlling features and processes. DSRSs are common in Calabria (southern Italy) where the complex geo-structural setting plays a key role in controlling the geometry of the failure surface and its development. This paper describes an integrated multi-disciplinary approach to investigate a DSRS in Palaeozoic high-grade metamorphic rocks of the Sila Massif; it focuses on the definition of the internal structure and the predisposing factors of the Serra di Buda landslide near the town of Acri, which is a paradigm for numerous landslides in this area. An integrated interdisciplinary study based on geological, structural, and geomorphological investigations-including field observations of weathering grade of rocks, minero-petrographic characterisations, geotechnical investigations and, in particular, fifteen years of displacement monitoring-is presented. Stereoscopic analysis of aerial photographs and field observations indicate that the Serra di Buda landslide consists of two distinct compounded bodies: (i) an older and dormant body ( 7 ha) and (ii) a more recent and active body ( 13 ha) that overlies the previous one. The active landslide shows movement linked to a deep-seated translational rock slide (block slide); the velocity scale ranges from slow (1.6 m/year during paroxysmal stages) to extremely slow (affected by weathering processes that significantly reduce the rock strength and facilitate the extensive failure of the Serra di Buda landslide. Finally, the landslide's internal structure, according to geotechnical investigations and displacement monitoring, is proposed. The proposed approach and the obtained results can be generalised to typify other deep landslides in similar geological settings.

  10. Redox front penetration in the fractured Toki Granite, central Japan: An analogue for redox reactions and redox buffering in fractured crystalline host rocks for repositories of long-lived radioactive waste

    International Nuclear Information System (INIS)

    Yamamoto, Koshi; Yoshida, Hidekazu; Akagawa, Fuminori; Nishimoto, Shoji; Metcalfe, Richard

    2013-01-01

    Highlights: • Deep redox front developed in orogenic granitic rock have been studied. • The process was controlled by the buffering capacity of minerals. • This is an analogue of redox front penetration into HLW repositories in Japan. - Abstract: Redox buffering is one important factor to be considered when assessing the barrier function of potential host rocks for a deep geological repository for long-lived radioactive waste. If such a repository is to be sited in fractured crystalline host rock it must be demonstrated that waste will be emplaced deeper than the maximum depth to which oxidizing waters can penetrate from the earth’s surface via fractures, during the assessment timeframe (typically 1 Ma). An analogue for penetration of such oxidizing water occurs in the Cretaceous Toki Granite of central Japan. Here, a deep redox front is developed along water-conducting fractures at a depth of 210 m below the ground surface. Detailed petrographical studies and geochemical analyses were carried out on drill core specimens of this redox front. The aim was to determine the buffering processes and behavior of major and minor elements, including rare earth elements (REEs), during redox front development. The results are compared with analytical data from an oxidized zone found along shallow fractures (up to 20 m from the surface) in the same granitic rock, in order to understand differences in elemental migration according to the depth below the ground surface of redox-front formation. Geochemical analyses by XRF and ICP-MS of the oxidized zone at 210 m depth reveal clear changes in Fe(III)/Fe(II) ratios and Ca depletion across the front, while Fe concentrations vary little. In contrast, the redox front identified along shallow fractures shows strong enrichments of Fe, Mn and trace elements in the oxidized zone compared with the fresh rock matrix. The difference can be ascribed to the changing Eh and pH of groundwater as it flows downwards in the granite, due to

  11. Neutron pole figures compared with magnetic preferred orientations of different rock types

    International Nuclear Information System (INIS)

    Hansen, Anke; Chadima, Martin; Cifelli, Francesca; Brokmeier, H.-G.Heinz-Guenter; Siemes, Heinrich

    2004-01-01

    Neutron diffraction is an excellent tool for pole figure measurement of rock samples. Due to high penetration depth of neutrons for most materials neutron diffraction represents an efficient tool to measure complete pole figures with reliable grain statistics even in coarse grained or inequi-granular materials. In the field of structural geology, the measurement of anisotropy of magnetic susceptibility is a standard technique to reveal the tectonic history of deformed rocks. The application of both techniques on still ongoing studies of Precambrian, Carboniferous and Quaternary rocks which are characterised by fundamental different tectonic evolutions and mineralogical compositions shows the wide field of relevance and importance of these methods in understanding tectonic processes in detail

  12. Metamorphic rock-hosted orogenic gold deposit style at Bombana (Southeast Sulawesi and Buru Island (Maluku: Their key features and significances for gold exploration in Eastern Indonesia

    Directory of Open Access Journals (Sweden)

    Arifudin Idrus

    2017-06-01

    Full Text Available In Indonesia, gold is commonly mined from epithermal-, porphyry-, and skarn-type deposits that are commonly found in volcanic belts along island arcs or active continental margin settings. Numerous gold prospects, however, were recently discovered in association with metamorphic rocks. This paper focuses on metamorphic rock-hosted gold mineralization in Eastern Indonesia, in particular the Bombana (SE Sulawesi and Buru Island (Maluku prospects. At Bombana, gold-bearing quartz-veins are hosted by the Pompangeo metamorphic complex. Sheared, segmented veins vary in thickness from 2 cm to 2 m. Gold is mainly present in the form of ‘free gold’ among silicate minerals and closely related to cinnabar, stibnite, tripuhyite, and in places, minor arsenopyrite. The gold distribution is erratic, however, ranging from below detection limit up to 134 g/t. At least three generations of veins are identified. The first is parallel to the foliation, the second crosscuts the first generation of veins as well as the foliation, and the late-stage laminated deformed quartz-calcite vein represents the third mineralization stage. The early veins are mostly massive to crystalline, occasionally brecciated, and sigmoidal, whereas the second-stage veins are narrower than the first ones and less subjected to brecciation. Gold grades in the second- and third-stage veins are on average higher than that in the earlier veins. Microthermometric and Raman spectrometric studies of fluid inclusions indicate abundant H2O-NaCl and minor H2O-NaCl-CO2 fluids. Homogenization temperatures and salinities vary from 114 to 283 ºC and 0.35 to 9.08 wt.% NaCl eq., respectively. Crush-leach analysis of fluid inclusions suggests that the halogen fluid chemistry is not identical to sea water, magmatic or epithermal related fluids, but tends to be similar to fluids in mesothermal-type gold deposits. In Buru Island (Gunung Botak and Gogorea prospects, two distinct generations of quartz veins

  13. Fracture characteristics in Japanese rock

    International Nuclear Information System (INIS)

    Ijiri, Yuji; Sawada, Atsushi; Akahori, Kuniaki

    1999-11-01

    It is crucial for the performance assessment of geosphere to evaluate the characteristics of fractures that can be dominant radionuclide migration pathways from a repository to biosphere. This report summarizes the characteristics of fractures obtained from broad literature surveys and the fields surveys at the Kamaishi mine in northern Japan and at outcrops and galleries throughout the country. The characteristics of fractures described in this report are fracture orientation, fracture shape, fracture frequency, fracture distribution in space, transmissivity of fracture, fracture aperture, fracture fillings, alteration halo along fracture, flow-wetted surface area in fracture, and the correlation among these characteristics. Since granitic rock is considered the archetype fractured media, a large amount of fracture data is available in literature. In addition, granitic rock has been treated as a potential host rock in many overseas programs, and has JNC performed a number of field observations and experiments in granodiorite at the Kamaishi mine. Therefore, the characteristics of fractures in granitic rock are qualitatively and quantitatively clarified to some extent in this report, while the characteristics of fractures in another rock types are not clarified. (author)

  14. ADDIGAS. Advective and diffusive gas transport in rock salt formations. Final report

    International Nuclear Information System (INIS)

    Jockwer, Norbert; Wieczorek, Klaus

    2008-04-01

    Beside granite and clay formations also rock salt is investigated as potential host rock for the disposal or radioactive waste. As a result of the mining activities the stress and strain state is changed which leads to dilatancy (i.e., volume increase, manly caused by microfracturing) in the vicinity of the excavations. The affected area is termed as Excavation Disturbed Zone (EDZ) and is characterized by an increased porosity and permeability with micro- and potential macrofractures. For the radioactive waste disposal in a geologic formation the properties of the EDZ with its permeability, extent, and evolution with time is of importance especially for the construction and building of geotechnical barriers. In the recent years the EDZ in rock salt formations was investigated at GRS in the frame of various projects. Main subjects of these projects were the characterisation of the EDZ with regard to its extent, hydraulic behaviour and possible healing at the in-situ stress conditions. The main emphasis of the ADDIGAS project reported here was the evolution of the EDZ after cutting off the drift contour, the anisotropy of permeability, and the diffusive gas transport which had not been investigated in earlier projects. Moreover, an constitutive model for calculating EDZ behaviour which had been developed in the frame of the BAMBUS II project was tested. The experimental work was performed on the 800-m level of the ASSe salt mine. The project ran from 2004 to 2007 and was funded by German Ministry of Economics and Labour (BMWA) under the contract No. 02 E 9924. The modelling work was co-funded by the CEC in the frame of the Integrated Project NF-PRO under contract no. F16W-CT-2003-002389. (orig.)

  15. Further characterisation of two Eimeria species (Eimeria quokka and Eimeria setonicis) in quokkas (Setonix brachyurus).

    Science.gov (United States)

    Austen, J M; Friend, J A; Yang, R; Ryan, U M

    2014-03-01

    The identification and characterisation of novel Eimeria species has largely been based on sporulated oocyst and sporocyst morphology, the host species and the geographical range. Variation in the size and shape of Eimeria oocysts across their host range however, make the identification and characterisation of novel species using traditional methodologies alone problematic. The use of molecular markers and phylogenetic analysis has greatly advanced our ability to characterise Eimeria species and has recently been applied to understand evolutionary relationships among Eimeria species from Australian marsupials. In the present study, Eimeria species isolated from quokkas (Setonix brachyurus) captured from Two Peoples Bay, Bald Island and Rottnest Island, Western Australia, were morphologically identified as Eimeria quokka and Eimeria setonicis. Both Eimeria species were identified as being polymorphic in nature with regards to sporulated oocyst and sporocyst morphometrics. Phylogenetic analysis using 18S rRNA and COI (cytochrome c oxidase subunit 1) genes, grouped E. quokka and E. setonicis within the Eimeria marsupial clade together with Eimeria trichosuri from brushtail possums, Eimeria macropodis from tammar wallabies (Macropus eugenii) and several unidentified macropod Eimeria species from western grey kangaroos (Macropus fuliginosus). This study is the first to characterise E. quokka and E. setonicis by molecular analysis, enabling more extensive resolution of evolutionary relationships among marsupial-derived Eimeria species. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Rock mass mechanical property estimations for the Yucca Mountain Site Characterization Project

    International Nuclear Information System (INIS)

    Lin, M.; Hardy, M.P.; Bauer, S.J.

    1993-06-01

    Rock mass mechanical properties are important in the design of drifts and ramps. These properties are used in evaluations of the impacts of thermomechanical loading of potential host rock within the Yucca Mountain Site Characterization Project. Representative intact rock and joint mechanical properties were selected for welded and nonwelded tuffs from the currently available data sources. Rock mass qualities were then estimated using both the Norwegian Geotechnical Institute (Q) and Geomechanics Rating (RMR) systems. Rock mass mechanical properties were developed based on estimates of rock mass quality, the current knowledge of intact properties, and fracture/joint characteristics. Empirical relationships developed to correlate the rock mass quality indices and the rock mass mechanical properties were then used to estimate the range of rock mass mechanical properties

  17. Rocks and geology in the San Francisco Bay region

    Science.gov (United States)

    Stoffer, Philip W.

    2002-01-01

    The landscape of the San Francisco Bay region is host to a greater variety of rocks than most other regions in the United States. This introductory guide provides illustrated descriptions of 46 common and important varieties of igneous, sedimentary, and metamorphic rock found in the region. Rock types are described in context of their identification qualities, how they form, and where they occur in the region. The guide also provides discussion about of regional geology, plate tectonics, the rock cycle, the significance of the selected rock types in relation to both earth history and the impact of mineral resources on the development in the region. Maps and text also provide information where rocks, fossils, and geologic features can be visited on public lands or in association with public displays in regional museums, park visitor centers, and other public facilities.

  18. Climax Granite, Nevada Test Site, as a host for a rock mechanics test facility related to the geologic disposal of high level nuclear wastes

    International Nuclear Information System (INIS)

    Heuze, F.E.

    1981-02-01

    This document discusses the potential of the Climax pluton, at the Nevada Test Site, as the host for a granite mechanics test facility related to the geologic disposal of high-level nuclear waste. The Climax granitic pluton has been the site of three nuclear weapons effects tests: Hard Hat, Tiny Tot, and Piledriver. Geologic exploration and mapping of the granite body were performed at the occasion of these tests. Currently, it is the site Spent Fuel Test (SFT-C) conducted in the vicinity of and at the same depth as that of the Piledriver drifts. Significant exploration, mapping, and rock mechanics work have been performed and continue at this Piledriver level - the 1400 (ft) level - in the context of SFT-C. Based on our technical discussions, and on the review of the significant geological and rock mechanics work already achieved in the Climax pluton, based also on the ongoing work and the existing access and support, it is concluded that the Climax site offers great opportunities for a rock mechanics test facility. It is not claimed, however, that Climax is the only possible site or the best possible site, since no case has been made for another granite test facility in the United States. 12 figures, 3 tables

  19. Characterisation and geostatistical analysis of clay rocks in underground facilities using hyper-spectral images

    International Nuclear Information System (INIS)

    Becker, J.K.; Marschall, P.; Brunner, P.; Cholet, C.; Renard, P.; Buckley, S.; Kurz, T.

    2012-01-01

    Document available in extended abstract form only. Flow and transport processes in geological formations are controlled by the porosity and permeability which in turn are mainly controlled by the fabric and the mineralogical composition of the rock. For the assessment of transport processes in water-saturated Clay-stone formations, the relevant scales are ranging essentially from kilometers to nanometers. The spatial variability of the mineralogical composition is a key indicator for the separation of transport scales and for the derivation of the effective transport properties at a given scale. Various laboratory and in-situ techniques are available for characterizing the mineralogical composition of a rock on different scales. The imaging spectroscopy presented in this paper is a new site investigation method suitable for mapping the mineralogical composition of geological formations in 2D on a large range of scales. A combination of imaging spectrometry with other site characterization methods allows the inference of the spatial variability of the mineralogical composition in 3D over a wide range of scales with the help of advanced geostatistical methods. The method of image spectrometry utilizes the fact that the reflection of electromagnetic radiation from a surface is a function of the wavelength, the chemical-mineralogical surface properties, and physical parameters such as the grain size and surface roughness. In remote sensing applications using the sun as the light source, the reflectance is measured within the visible and infrared range, according to the atmospheric transmissibility. Many rock-forming minerals exhibit diagnostic absorption features within this range, which are caused by electronic and vibrational processes within the crystal lattice. The exact wavelength of an absorption feature is controlled by the type of ion, as well as the position of the ion within the lattice. Spectral signatures of minerals are described by a number of authors

  20. Review of potential host rocks for radioactive waste disposal in the Piedmont Province of South Carolina

    International Nuclear Information System (INIS)

    Secor, D.T. Jr.

    1980-10-01

    This report reviews the geology of the Piedmont Province of South Carolina with the aim of designating rock units favorable for field exploration for a potential underground repository for the storage of radioactive waste. Most of the rocks in the South Carolina Piedmont are metamorphosed sedimentary volcanic or igneous rocks that have experienced at least one episode of strong deformation. As a consequence of this deformation, they have irregular shapes, making it difficult to predict their subsurface extent. In evaluating the suitability of the rock units for radioactive waste storage, certain criteria were found to be particularly useful. The requirements that the storage site be located in a large volume of homogeneous, impermeable, relatively unfractured rock was the most important criteria in eliminating most of the Piedmont rock units for consideration as field study areas. Six large late- to post-tectonic igneous plutons (Winnsboro, Liberty Hill, Ogden, Newberry, Lowrys, and Bald Rock) are recommended as field study areas

  1. Shaft sealing concepts for high-level radioactive waste repositories based on the host-rock options rock salt and clay stone; Schachtverschlusskonzepte fuer zukuenftige Endlager fuer hochradioaktive Abfaelle fuer die Wirtsgesteinsoptionen Steinsalz und Ton

    Energy Technology Data Exchange (ETDEWEB)

    Kudla, Wolfram; Gruner, Matthias [TU Bergakademie Freiberg (Germany). Inst. fuer Erdbau und Spezialtiefbau; Herold, Philipp; Jobmann, Michael [DBE Technology GmbH, Peine (Germany)

    2015-07-01

    Unlike the shaft barriers used for the dry preservation of former mine workings and underground storage sites, shaft seals designed for radioactive-waste repositories must also fulfil additional requirements associated with the design diversity of the sealing system. This diversity makes use of the simple redundancy principle in order to prevent the proliferation of defects. In practice this means combining several sealing elements made from different materials or from materials with different properties. The R and D project, Shaft sealing systems for final repositories for high-level radioactive waste (ELSA) - phase 2: concept design for shaft seals and testing of the functional elements of shaft seals', which was funded by the Federal Ministry for Economic Affairs and Energy (BMWi), set out to investigate potential sealing elements for the two host-rock options rock salt and mudstone. This paper combines the text that the authors presented at the First International Freiberg Shaft Colloquium held at the Freiberg University of Mining and Technology on 01.10.2014 with a presentation on the sealing elements that were investigated as part of the R and D project.

  2. First characterisation of the "Rumi-Pana" rock avalanche deposits (Famatina Range, La Rioja, Argentina)

    Science.gov (United States)

    Santiago Pullarello, José; Derron, Marc-Henri; Penna, Ivanna; Leiva, Alicia; Jaboyadoff, Michel

    2017-04-01

    Active mountain fronts are subject to large scale slope collapses which have the capacity to run long distances on piedmont areas. Along time, fluvial activity and other gravitatory processes can intensively erode and mask primary features related to the collapses. Therefore, to reconstruct the history of their occurrence, further analyses are needed, e.g. sedimentologic analyses. This work focuses on the occurrence of large rock avalanches in the Vinchina region, La Rioja (28°43'27.81'' S / 68°00'25.42'' W) on the western side of the Famatina range(Argentina). Here, photointerpretation of high resolution satellite images (Google Earth) allowed us to identify two rock avalanches, main scarps developed at 2575 and 2750 m a.s.l. . There are no absolute ages for these deposits, however, comparing their preservation degree with those dated further north (in similar climatic and landscape dynamics contexts [i]), we can suggest these rock avalanches took place during the Pleistocene. We carried out a fieldwork survey in this remote area, including classical landslide mapping, structural analysis, deposits characterization and sampling. The deposits reach the valley bottom (at around 1700 m a.s.l.) with runouts about 5 and 5.3 km long. In one of the cases, the morphology of the deposit is well preserved, allowing to reconstruct accurately its extension. However, in the second case, the deposits are strongly eroded by courses draining the mountain front, therefore further analyses should be done to reconstruct its extension. In addition to morphologic interpretations, a multiscale grain-size analysis was done to differentiate rock avalanches from other hillslope deposits: (1) 3D surface models of surface plots (5x5m) have been built by SfM photogrammetry; 2) classical sieving and 3) laser grain-size analysis of deposits. Samples were collected on different parts of the slope, but also along cross sections through the avalanche deposit. This deposits characterization will

  3. The carbonaceous phyllite rock-hosted Pedra Verde copper mine, Borborema Province, Brazil: Stable isotope constraints, structural controls and metallogenic evolution

    Science.gov (United States)

    da Silva Nogueira de Matos, José Henrique; Saraiva dos Santos, Ticiano José; Virgínia Soares Monteiro, Lena

    2017-12-01

    The Pedra Verde Copper Mine is located in the Viçosa do Ceará municipality, State of Ceará, NE Brazil. The copper mineralization is hosted by the Pedra Verde Phyllite, which is a carbonaceous chlorite-calcite phyllite with subordinate biotite. It belongs to the Neoproterozoic Martinópole Group of the Médio Coreaú Domain, Borborema Province. The Pedra Verde deposit is stratabound and its ore zoning is conspicuous, according to the following sequence, from bottom to top: marcasite/pyrite, native silver, chalcopyrite, bornite, chalcocite, native copper and hematite. Barite and carbonaceous material are reported in ore zones. Zoning reflects the ore formation within a redox boundary developed due to the interaction between oxidized copper- and sulfate-bearing fluids and the reduced phyllite. Structural control on mineralization is evidenced by the association of the ore minerals with veins, hinge folds, shadow pressures, and mylonitic foliation. It was mainly exercised by a dextral transcurrent shear zone developed during the third deformational stage identified in the Médio Coreaú Domain between 590 Ma and 570 Ma. This points to the importance of epigenetic, post-metamorphic deformational events for ore formation. Oxygen isotopic composition (δ18OH2O = 8.94 to 11.28‰, at 250 to 300 °C) estimated for the hydrothermal fluids in equilibrium with calcite indicates metamorphic or evolved meteoric isotopic signatures. The δ13CPDB values (-2.60 to -9.25‰) obtained for hydrothermal calcite indicate mixing of carbon sources derived from marine carbonate rocks and carbonaceous material. The δ34SCDT values (14.88 to 36.91‰) of sulfides suggest evaporites as sulfate sources or a closed system in relation to SO42- availability to form H2S. Carbonaceous matter had a key role in thermochemical sulfate processes and sulfide precipitation. The Pedra Verde Copper Mine is considered the first stratabound meta-sedimentary rock-hosted copper deposit described in Brazil

  4. Foliation: Geological background, rock mechanics significance, and preliminary investigations at Olkiluoto

    International Nuclear Information System (INIS)

    Milnes, A.G.; Hudson, J.; Wikstroem, L.; Aaltonen, I.

    2006-01-01

    A well developed, pervasive foliation is a characteristic feature of the migmatites and gneisses in the Olkiluoto bedrock, and is expected to have a significant influence on the underground construction, the design and layout and the groundwater flow regime of a deep spent nuclear fuel repository. This Working Report reviews the geological background and rock mechanics significance of foliation, and develops a methodology for the systematic acquisition of foliation data in cored boreholes and in tunnels at the Olkiluoto site, to provide the necessary basis for future geological, rock mechanics and hydrogeological modelling. The first part of the methodology concerns foliation characterisation, and develops a characterisation scheme based on two variables: the foliation type (G = gneissic, B = banded, S = schistose), which is a function of mineral composition and degree of smallscale heterogeneity, and the foliation intensity (1 = low, 2 = intermediate, 3 = high), which is a function of the type and intensity of the deformation by which it was produced (under high-grade metamorphic conditions in the core of the Svecofennian orogenic belt). At the suggested reference scales (1 m length of core, 10 m 2 area of tunnel wall), the most representative foliation type and intensity is assessed using a standard set of core photographs, which are included as an Appendix at the end of the report, providing a systematic description in terms of 9 descriptive types (G1, G2, G3, B1, B2, B3, S1, S2, S3). As a further step, the rock mechanics significance of these types is assessed and a rock mechanics foliation (RMF) number is assigned (RMF 0 = no significance, RMF 1, RMF 2 and RMF 3 = low, intermediate and high significance, respectively). The second part of the methodology concerns the orientations of the foliation within the same 1 m core lengths or 10 m2 wall areas, which have been characterised as above. This combined analysis of foliation character and foliation orientation

  5. Marble-hosted ruby deposits of the Morogoro Region, Tanzania

    Science.gov (United States)

    Balmer, Walter A.; Hauzenberger, Christoph A.; Fritz, Harald; Sutthirat, Chakkaphan

    2017-10-01

    The ruby deposits of the Uluguru and Mahenge Mts, Morogoro Region, are related to marbles which represent the cover sequence of the Eastern Granulites in Tanzania. In both localities the cover sequences define a tectonic unit which is present as a nappe structure thrusted onto the gneissic basement in a north-western direction. Based on structural geological observations the ruby deposits are bound to mica-rich boudins in fold hinges where fluids interacted with the marble-host rock in zones of higher permeability. Petrographic observations revealed that the Uluguru Mts deposits occur within calcite-dominated marbles whereas deposits in the Mahenge Mts are found in dolomite-dominated marbles. The mineral assemblage describing the marble-hosted ruby deposit in the Uluguru Mts is characterised by corundum-dolomite-phlogopite ± spinel, calcite, pargasite, scapolite, plagioclase, margarite, chlorite, tourmaline whereas the assemblage corundum-calcite-plagioclase-phlogopite ± dolomite, pargasite, sapphirine, titanite, tourmaline is present in samples from the Mahenge Mts. Although slightly different in mineral assemblage it was possible to draw a similar ruby formation history for both localities. Two ruby forming events were distinguished by textural differences, which could also be modeled by thermodynamic T-XCO2 calculations using non-ideal mixing models of essential minerals. A first formation of ruby appears to have taken place during the prograde path (M1) either by the breakdown of diaspore which was present in the original sedimentary precursor rock or by the breakdown of margarite to corundum and plagioclase. The conditions for M1 metamorphism was estimated at ∼750 °C at 10 kbar, which represents granulite facies conditions. A change in fluid composition towards a CO2 dominated fluid triggered a second ruby generation to form. Subsequently, the examined units underwent a late greenschist facies overprint. In the framework of the East African Orogen we

  6. Small mammals as hosts of immature ixodid ticks

    Directory of Open Access Journals (Sweden)

    I.G. Horak

    2005-09-01

    Full Text Available Two hundred and twenty-five small mammals belonging to 16 species were examined for ticks in Free State, Mpumalanga and Limpopo Provinces, South Africa, and 18 ixodid tick species, of which two could only be identified to genus level, were recovered. Scrub hares, Lepus saxatilis, and Cape hares, Lepus capensis, harboured the largest number of tick species. In Free State Province Namaqua rock mice, Aethomys namaquensis, and four-striped grass mice, Rhabdomys pumilio, were good hosts of the immature stages of Haemaphysalis leachi and Rhipicephalus gertrudae, while in Mpumalanga and Limpopo Provinces red veld rats, Aethomys chrysophilus, Namaqua rock mice and Natal multimammate mice, Mastomys natalensis were good hosts of H. leachi and Rhipicephalus simus. Haemaphysalis leachi was the only tick recovered from animals in all three provinces.

  7. Mercury isotope constraints on the source for sediment-hosted lead-zinc deposits in the Changdu area, southwestern China

    Science.gov (United States)

    Xu, Chunxia; Yin, Runsheng; Peng, Jiantang; Hurley, James P.; Lepak, Ryan F.; Gao, Jianfeng; Feng, Xinbin; Hu, Ruizhong; Bi, Xianwu

    2018-03-01

    The Lanuoma and Cuona sediment-hosted Pb-Zn deposits hosted by Upper Triassic limestone and sandstone, respectively, are located in the Changdu area, SW China. Mercury concentrations and Hg isotopic compositions from sulfide minerals and potential source rocks (e.g., the host sedimentary rocks and the metamorphic basement) were investigated to constrain metal sources and mineralization processes. In both deposits, sulfide minerals have higher mercury (Hg) concentrations (0.35 to 1185 ppm) than the metamorphic basement rocks (0.05 to 0.15 ppm) and sedimentary rocks (0.02 to 0.08 ppm). Large variations of mass-dependent fractionation (3.3‰ in δ202Hg) and mass-independent fractionation (0.3‰ in Δ199Hg) of Hg isotopes were observed. Sulfide minerals have Hg isotope signatures that are similar to the hydrothermal altered rocks around the deposit, and similar to the metamorphic basement, but different from barren sedimentary rocks. The variation of Δ199Hg suggests that Hg in sulfides was mainly derived from the underlying metamorphic basement. Mercury isotopes could be a geochemical tracer in understanding metal sources in hydrothermal ore deposits.

  8. Thermal conductivity of the rocks in the Bureau of Mines Standard Rock Suite

    International Nuclear Information System (INIS)

    Morgan, M.T.; West, G.A.

    1980-01-01

    Thermal conductivities of eight rocks from the Bureau of Mines Standard Rock Suite were measured in air over the temperature range 373 to 533 0 K (100 to 260 0 C). The thermal conductivities of these rocks were measured to furnish standards for future comparisons with host rock from prospective nuclear waste repository sites. The thermal conductivity at a given temperature decreased by as much as 9% after a specimen had been heated to the maximum temperature (533 0 K), but additional heating cycles had no further effect. This decrease was smallest in the igneous rocks and largest in the sedimentary types. Variations due to orientation were within the precision of measurements (+- 5%). In most cases the thermal conductivities were linear with the reciprocal of the temperature and were within 14% of published data obtained by other methods. Measurements were made by a cut-bar comparison method in which the sample was sandwiched between two reference or metering bars made of Pyroceram 9606 glass-ceramic. The apparatus consisted of a Dynatech Model TCFCM-N20 comparative thermal conductivity analyzer controlled by a Hewlett Packard Model 3052A data acquisition system. A program was written to increment and cycle the temperature in steps between predetermined initial and maximum values. At each step the thermal conductivity was measured after steady-state conditions were established. The rocks furnished by the Bureau of Mines were quarried in large and fairly homogeneous lots for use by researchers at various laboratories. To investigate any anisotropy, cores were taken from each rock cube perpendicular to each of the cube faces. Samples 2 in. in diameter and approx. 0.75 in. thick were prepared from the cores and were dried in a vacuum oven for at least one month prior to taking measurements

  9. Review of Studies of Clay Minerals as Significant Component of Potential Host Rocks or Engineering Barriers for Radioactive Waste Disposals Performed at Comenius University in Bratislava

    International Nuclear Information System (INIS)

    Peter, Uhlik; Vladimir, Sucha; Maria, Caplovicova; Igor, Stricek

    2013-01-01

    About 50 % of electric power is produced by nuclear power plants in Slovakia. In spite of the significant production of nuclear waste, Slovakia has not defined basic strategy of radioactive-waste isolation. However, some pilot projects and studies have been carried out. Five areas were determined as prospective sites for construction of deep geological repository (DGR). Two of them are situated in the south of Slovakia. Szecseny schlier (mixture of siltstones and Clay-stones) of Lucenec Formation (Egerian) is one of the most prospective host rocks from lithological, structural and spatial perspective. Besides the investigation of potential host rock for DGR the studies of bentonite properties as important part of engineering barriers for radioactive waste disposals were performed. Detailed mineral and structural analyses of smectites from the bentonitic material exposed to laboratory Mock-Up test were realised. Particular interest has been focused on interaction between Fe and smectites. Other field of interest is investigation of sorption of Cs and Sr on natural and modified bentonites, including irradiation. Purpose of this work is to present a short review of other studies done by our group with partial focusing to interaction of organic dye (Rhoda-mine 6G) with smectite that is connected with changes of layer charge after treatment; possibilities to measure preferential orientation of clays after compaction by TEM and to effort to use X-ray micro-tomography for inner structure of sediments. (authors)

  10. Impact of weathering on slope stability in soft rock mass

    Directory of Open Access Journals (Sweden)

    Predrag Miščević

    2014-06-01

    Full Text Available Weathering of soft rocks is usually considered as an important factor in various fields such as geology, engineering geology, mineralogy, soil and rock mechanics, and geomorphology. The problem of stability over time should be considered for slopes excavated in soft rocks, in case they are not protected against weathering processes. In addition to disintegration of material on slope surface, the weathering also results in shear strength reduction in the interior of the slope. Principal processes in association with weathering are discussed with the examples of marl hosted on flysch formations near Split, Croatia.

  11. Strategy for a Rock Mechanics Site Descriptive Model. Development and testing of the theoretical approach

    Energy Technology Data Exchange (ETDEWEB)

    Staub, Isabelle; Fredriksson, Anders; Outters, Nils [Golder Associates AB, Uppsala (Sweden)

    2002-05-01

    In the purpose of studying the possibilities of a Deep Repository for spent fuel, the Swedish Nuclear and Fuel Management Company (SKB) is currently planning for Site Investigations. Data collected from these Site Investigations are interpreted and analysed to achieve the full Site Description, which is built up of models from all the disciplines that are considered of importance for the Site Description. One of these models is the Rock Mechanical Descriptive Model,which would be developed for any site in hard crystalline rock, and is a combination and evaluation of the characterisation of rock mass by means of empirical relationships and a theoretical approach based on numerical modelling. The present report describes the theoretical approach. The characterisation of the mechanical properties of the rock mass, viewed as a unit consisting of intact rock and fractures, is achieved by numerical simulations with following input parameters: initial stresses, fracture geometry, distribution of rock mechanical properties, such as deformation and strength parameters, for the intact rock and for the fractures. The numerical modelling was performed with the two-dimensional code UDEC, and the rock block models were generated from 2D trace sections extracted from the 3D Discrete Fracture Network (DFN) model. Assumptions and uncertainties related to the set-up of the model are considered. The numerical model was set-up to simulate a plain strain-loading test. Different boundary conditions were applied on the model for simulating stress conditions (I) in the undisturbed rock mass, and (II) at the proximity of a tunnel. In order to assess the reliability of the model sensitivity analyses have been conducted on some rock block models for defining the dependency of mechanical properties to in situ stresses, the influence of boundary conditions, rock material and joint constitutive models used to simulate the behaviour of intact rock and fractures, domain size and anisotropy. To

  12. Strategy for a Rock Mechanics Site Descriptive Model. Development and testing of the theoretical approach

    International Nuclear Information System (INIS)

    Staub, Isabelle; Fredriksson, Anders; Outters, Nils

    2002-05-01

    In the purpose of studying the possibilities of a Deep Repository for spent fuel, the Swedish Nuclear and Fuel Management Company (SKB) is currently planning for Site Investigations. Data collected from these Site Investigations are interpreted and analysed to achieve the full Site Description, which is built up of models from all the disciplines that are considered of importance for the Site Description. One of these models is the Rock Mechanical Descriptive Model,which would be developed for any site in hard crystalline rock, and is a combination and evaluation of the characterisation of rock mass by means of empirical relationships and a theoretical approach based on numerical modelling. The present report describes the theoretical approach. The characterisation of the mechanical properties of the rock mass, viewed as a unit consisting of intact rock and fractures, is achieved by numerical simulations with following input parameters: initial stresses, fracture geometry, distribution of rock mechanical properties, such as deformation and strength parameters, for the intact rock and for the fractures. The numerical modelling was performed with the two-dimensional code UDEC, and the rock block models were generated from 2D trace sections extracted from the 3D Discrete Fracture Network (DFN) model. Assumptions and uncertainties related to the set-up of the model are considered. The numerical model was set-up to simulate a plain strain-loading test. Different boundary conditions were applied on the model for simulating stress conditions (I) in the undisturbed rock mass, and (II) at the proximity of a tunnel. In order to assess the reliability of the model sensitivity analyses have been conducted on some rock block models for defining the dependency of mechanical properties to in situ stresses, the influence of boundary conditions, rock material and joint constitutive models used to simulate the behaviour of intact rock and fractures, domain size and anisotropy. To

  13. Site-specific evaluation of safety issues for high-level waste disposal in crystalline rocks. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Jobmann, M. (ed.) [DBE Technology GmbH, Peine (Germany)

    2016-03-31

    In the past, German research and development (R and D) activities regarding the disposal of radioactive waste, including spent nuclear fuel, focused mainly on domal rock salt because rock salt was the preferred host rock formation. In addition, generic R and D work regarding alternative host rocks (crystalline rocks and claystones) had been performed as well for a long time but with lower intensity. Around the year 2000, as a consequence of the moratorium on the Gorleben site, the Federal Government decided to have argillaceous rocks and crystalline rocks investigated in more detail. As Germany does not have any underground research and host rock characterization facilities, international cooperation received a high priority in the German R and D programme for high-level waste (HLW) disposal in order to increase the knowledge regarding alternative host rocks. Major cornerstones of the cooperation are joint projects and experiments conducted especially in underground research laboratories (URL) in crystalline rocks at the Grimsel Test Site (Switzerland) and the Hard Rock Laboratory (HRL) Aespoe(Sweden) and in argillaceous rocks at the URL Mont Terri (Switzerland) and Bure (France). In 2001, the topic of radioactive waste disposal was integrated into the agreement between the former Russian Ministry of Atomic Energy (Minatom, now Rosatom) and the German Ministry of Labor (BMWA), now Ministry of Economic Affairs and Energy (BMWi), on cooperation regarding R and D on the peaceful utilization of nuclear power (agreement on ''Wirtschaftlich-Technische Zusammenarbeit'' WTZ). The intention was to have a new and interesting opportunity for international R and D cooperation regarding HLW disposal in crystalline rocks and the unique possibility to perform site-specific work, to test the safety demonstration tools available, and to expand the knowledge to all aspects specific to these host rocks. Another motivation for joining this cooperation was the

  14. A physico-chemical characterisation technique for determining the pore-water chemistry in argillaceous rocks

    International Nuclear Information System (INIS)

    Baeyens, B.; Bradbury, M.H.

    1991-09-01

    A prerequisite for carrying out credible sorption studies is the definition of an aqueous phase composition which is in equilibrium with the solid phase. Experimental methods and data analysis procedures are described which enable an equilibrium water composition to be produced for argillaceous rocks which is not dependent on liquid to solid (L:S) ratios. Since a Valanginian marl formation is under consideration by Nagra as a potential rock for the disposal of low and short-lived medium level radioactive waste in Switzerland, samples of this material were chosen for this investigation. Aqueous phase and nickel ethylenediamine extraction experiments were carried out at different L:S ratios under controlled atmosphere conditions (P CO 2 =10 -2 bar, O 2 ≤ 5 ppm ). The results from these tests and petrographical examinations were combined to define the system in terms of the physico-chemical characteristics of the clay mineral component (CEC and cation occupancies) and the identities of highly soluble and solubility limited phases in the marl. The geochemical code PHREEQE was used in conjunction with the Gapon equations to calculate the pore water composition. This work clearly showed that pore water chemistries obtained from aqueous extracts alone may lead to an arbitrary water chemistry in argillaceous rock systems, particularly with respect to ionic composition and ionic strength, which may have important consequences for radionuclide speciation and sorption studies. (author) 11 figs., 12 tabs., 25 refs

  15. Shear-flow coupling in non-planar rock joints

    International Nuclear Information System (INIS)

    Makurat, A.; Barton, N.

    1985-01-01

    Crystalline rock masses are regarded as a possible host rock for permanent nuclear waste disposal. During the excavation of the required shafts and tunnels, the initial state of stress will be changed and cause a deformation of the rock mass and discontinuities. During the lifetime of the nuclear repository joint apertures may change due to thermally induced stress variations during the heating and cooling phase. As the conductivity of a joint is very sensitive to its aperture, fluid flow from and towards a repository, as well as the potential transport times of radionuclides are highly dependent on the deformability of the joints. Theoretical calculations of coupled flow in rock joints (Barton et al. 1984) predict an increase of conductivity of several orders of magnitude for the first few millimeters for shear displacement. The shear-dilation-conductivity coupling for two block sizes at two effective stress levels is shown

  16. Review of potential host rocks for radioactive waste disposal in the Piedmont Province of Georgia

    International Nuclear Information System (INIS)

    Wenner, D.B.; Gillon, K.A.

    1980-10-01

    A literature study was conducted on the Piedmont province of Georgia to designate areas that may be favorable for field exploration for consideration of a repository for storage of radioactive waste. The criteria utilized in such a designation was based upon consideration of the rock unit having favorable geological, geotechnical, and geohydrological features. The most important are that the rock unit have: (1) satisfactory unit dimensions (> 100 km 2 outcrop area and at least 1500 meters (approx. 5000 feet) depth of a continuous rock type); and (2) acceptable geohydrological conditions. Among all rock types, it is concluded that the granites of the large post-metamorphic plutons and large, homogeneous orthogneissic units offer the most favorable geologic settings for exploration for siting a radioactive waste repository. Virtually all other rock types, including most metavolcanic and metasedimentary lithologies have unacceptable unit dimensions, generally unfavorable geohydrologic settings, and deleterious mechanical and physical geotechnical properties. After consideration of all major lithologies that comprise the Georgia Piedmont, the following units were deemed favorable: (1) the Elberton Pluton; (2) the Siloam Pluton; (3) the Sparta Pluton; (4) two unnamed plutons adjacent to the Snelson body of S.W. Georgia; (5) the Lithonia Gneiss; (6) basement orthogneisses and charnockites of the Pine Mountain Belt

  17. Deciphering fluid inclusions in high-grade rocks

    Directory of Open Access Journals (Sweden)

    Alfons van den Kerkhof

    2014-09-01

    Full Text Available The study of fluid inclusions in high-grade rocks is especially challenging as the host minerals have been normally subjected to deformation, recrystallization and fluid-rock interaction so that primary inclusions, formed at the peak of metamorphism are rare. The larger part of the fluid inclusions found in metamorphic minerals is typically modified during uplift. These late processes may strongly disguise the characteristics of the “original” peak metamorphic fluid. A detailed microstructural analysis of the host minerals, notably quartz, is therefore indispensable for a proper interpretation of fluid inclusions. Cathodoluminescence (CL techniques combined with trace element analysis of quartz (EPMA, LA-ICPMS have shown to be very helpful in deciphering the rock-fluid evolution. Whereas high-grade metamorphic quartz may have relatively high contents of trace elements like Ti and Al, low-temperature re-equilibrated quartz typically shows reduced trace element concentrations. The resulting microstructures in CL can be basically distinguished in diffusion patterns (along microfractures and grain boundaries, and secondary quartz formed by dissolution-reprecipitation. Most of these textures are formed during retrograde fluid-controlled processes between ca. 220 and 500 °C, i.e. the range of semi-brittle deformation (greenschist-facies and can be correlated with the fluid inclusions. In this way modified and re-trapped fluids can be identified, even when there are no optical features observed under the microscope.

  18. Final report of the TRUE Block Scale project. 1. Characterisation and model development

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Peter; Byegaard, Johan [Geosigma AB, Uppsala (Sweden); Dershowitz, Bill; Doe, Thomas [Golder Associates Inc., Redmond, WA (United States); Hermanson, Jan [Golder Associates AB (Sweden); Meier, Peter [ANDRA, Chatenay-Malabry (France); Tullborg, Eva-Lena [Terralogica AB (Sweden); Winberg, Anders (ed.) [Conterra AB, Partille (Sweden)

    2002-04-01

    The general objectives of the TRUE Block Scale Project were to 1) increase understanding of tracer transport in a fracture network and to improve predictive capabilities, 2) assess the importance of tracer retention mechanisms (diffusion and sorption) in a fracture network, and 3) assess the link between flow and transport data as a means for predicting transport phenomena. During the period mid 1996 through mid 1999 a 200x250x100 m rock volume was characterised with the purpose of furnishing the basis for successful tracer experiments in a network of conductive structures in the block scale (10-100 m). In total five cored boreholes were drilled as part of the project in an iterative mode with a period of analysis following completion of characterisation, and with a strong component of inter activity with numerical modelling and experimental design, particularly towards the end of the characterisation. The combined use of pressure responses due to drilling and drilling records provided important early information/confirmation of the existence and location of a given structure. Verification of conductors identified from pressure responses was achieved through the use of various flow logging techniques. The usage of the Posiva difference flow log towards the end of the characterisation work enabled identification of discrete conductive fractures with a high resolution. Pressure responses collected during drilling were used to obtain a first assessment of connectivity between boreholes. The transient behaviour of the responses collected during cross-hole interference tests in packed-off boreholes were used to identify families of responses, which correlated well with the identified principal families of structures/fracture networks. The conductive geometry of the investigated rock block is made up of steeply dipping deterministic NW structures and NNW structures. High inflows in the boreholes were for the most part associated with geologically/geometrically identified

  19. Final report of the TRUE Block Scale project. 1. Characterisation and model development

    International Nuclear Information System (INIS)

    Andersson, Peter; Byegaard, Johan; Dershowitz, Bill; Doe, Thomas; Hermanson, Jan; Meier, Peter; Tullborg, Eva-Lena; Winberg, Anders

    2002-04-01

    The general objectives of the TRUE Block Scale Project were to 1) increase understanding of tracer transport in a fracture network and to improve predictive capabilities, 2) assess the importance of tracer retention mechanisms (diffusion and sorption) in a fracture network, and 3) assess the link between flow and transport data as a means for predicting transport phenomena. During the period mid 1996 through mid 1999 a 200x250x100 m rock volume was characterised with the purpose of furnishing the basis for successful tracer experiments in a network of conductive structures in the block scale (10-100 m). In total five cored boreholes were drilled as part of the project in an iterative mode with a period of analysis following completion of characterisation, and with a strong component of inter activity with numerical modelling and experimental design, particularly towards the end of the characterisation. The combined use of pressure responses due to drilling and drilling records provided important early information/confirmation of the existence and location of a given structure. Verification of conductors identified from pressure responses was achieved through the use of various flow logging techniques. The usage of the Posiva difference flow log towards the end of the characterisation work enabled identification of discrete conductive fractures with a high resolution. Pressure responses collected during drilling were used to obtain a first assessment of connectivity between boreholes. The transient behaviour of the responses collected during cross-hole interference tests in packed-off boreholes were used to identify families of responses, which correlated well with the identified principal families of structures/fracture networks. The conductive geometry of the investigated rock block is made up of steeply dipping deterministic NW structures and NNW structures. High inflows in the boreholes were for the most part associated with geologically/geometrically identified

  20. Mineralogical and geochemical studies on apatites and phosphate host rocks of Esfordi deposit, Yazd province, to determine the origin and geological setting of the apatite

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Rajabzadeh

    2014-10-01

    Full Text Available Introduction Iron-apatite ore deposits well known as Kiruna iron type formed in association with calc-alkaline volcanism from Proterozoic to Tertiary (Hitzman et al., 1992. Liquid immiscibility in an igneous system was proposed to explain the formation of the iron oxides accompanying apatite in mineralized zones (Förster and Jafarzadeh, 1994; Daliran, 1999. The mode of ore formation however, is a matter in debate. Bafq region in Central Iran is one of the greatest iron mining regions in Iran with 750 million tons of reservoir. The majority of the iron deposits contains apatite as minor mineral and underwent metamorphism-alteration in varying degrees. The mode of formation and geological setting of Esfordi iron-apatite deposit in this region with an average of 13.9 wt% apatite are discussed using geochemical and mineralogical data along with field description. Materials and methods Fifty-three samples of mineralized zones and host rocks collected from 7 cross sections were studied by conventional microscopic methods. Seven representative samples were determined by XRD at Department of Physics, Shiraz University. Fifteen and six samples were also analyzed for major and trace elements using XRF at Binaloud Co. Iran, and ICP-MS at Labwest Minerals Analysis, Australia, respectively. Microprobe analyses were carried out on apatite in Geo Forschungs Zentrum Telegrafenberg at Potsdam University, Germany. Results Field observation shows that igneous host rocks in Esfordi were intensively altered by hydrothermal fluids. The ores are surrounded by wide altered halos. Petrographic investigation indicated that the most important alterations are of potassic, carbonatitic and silicification types. Magnetite and apatite occur as major minerals, accompanied by minor hematite and goethite in the mineralized zones. Rare Earth Element (REE minerals are present as minor phases in the ores. Three apatite mineralization types (vein, massive, and disseminated were

  1. Study of scenario 'mistake in determination of adsorbing properties of radionuclides on the materials of engineering barriers and host rock'

    International Nuclear Information System (INIS)

    Amosov, P.V.; Novozhilova, N.V.

    2008-01-01

    During investigations within the framework of this ASE of a storage facility, conceptual and mathematical models remained the same, as in SNE. Basic provisions of models, a solution 'tool' for diffusion equation taking into account radioactive decay and the chosen boundary conditions are presented in paper. The 79 Se isotope is chosen as basic analyzed radionuclide within the framework of the accepted ASE. The selection of this isotope can be substantiated by the following reasons: 1) Migration parameters of this radionuclide, in particular, the distribution coefficient of 79 Se isotope has specific enough values. For example, in granitoid formations (according to different research groups from Sweden, Finland, Switzerland during rather a small time range of experiments carrying out) the values of distribution coefficient vary within 20 times and thus its numerical value is small enough (0.0005 - 0.01 m 3 /kg). At the same time, the situation is reverse with cement materials: from references accessible to us only in one the value of this parameter is cited. 2) Performing calculations for the full list of radio-nuclides (in the SNE there were 8 of them) will require considerable labor expenditures and computer facilities resources: much processor time and much memory on a hard disk to store information. Since, when considering the selected ASE of facility there are accepted 4 areas of materials (the source, concrete, bentonite, the host rock) generally, it means practically a fourfold increase of all specified expenses in comparison with similar expenses for a SNE of facility. The main conclusions are: There are considered possible variants of error, which consequence is the 79 Se isotope transition in the category of a non-sorbing one in respective barrier of the near field that can conservatively lead to an increase of the facility hazard. If there is an error in selection of sorption parameters of 79 Se isotope in the host rock an increase in pollution of the

  2. Simulation of anions diffusion in Callovo-Oxfordian argillite by description of the rock microstructure

    International Nuclear Information System (INIS)

    Diaz, N.

    2008-01-01

    The Callovo-Oxfordian argillite has been proposed as host rock for deep underground radioactive wastes storage. The aim of this study is to determine the report of effective diffusion coefficients De(anion)/De(water) at the micrometer scale considering the spatial distribution of minerals in the rock. (A.L.B.)

  3. Spatially-resolved dust properties of the GRB 980425 host galaxy

    DEFF Research Database (Denmark)

    Michałowski, Michał J.; Hunt, L. K.; Palazzi, E.

    2014-01-01

    ), located 800 pc away from the GRB position. The host is characterised by low dust content and high fraction of UV-visible star-formation, similar to other dwarf galaxies. Such galaxies are abundant in the local universe, so it is not surprising to find a GRB in one of them, assuming the correspondence...

  4. Sorption data bases for generic Swiss argillaceous rock systems

    International Nuclear Information System (INIS)

    Bradbury, M. H.; Baeyens, B.; Thoenen, T.

    2010-09-01

    In Switzerland the site selection procedure for both high level waste (HLW) and low and intermediate level waste (L/ILW) repositories is specified by the Swiss Federal Office of Energy in the Sectoral Plan for Deep Geological Repositories. In the forthcoming stage 2 of this plan, potential sites will be identified within regions previously selected based on the presence of suitable host rocks, namely Opalinus Clay, 'Brauner Dogger', Effingen Member and Helvetic Marl. Preliminary safety analyses are an integral part of this procedure, and require, amongst other information, the radionuclide sorption properties of the host rock. This report describes a methodology to develop a Generic Rock Sorption Data Base (GR-SDB) for argillaceous rocks. The method will be used to compile specific SDBs for the above mentioned host rocks. Arguments are presented that the main factor influencing sorption on argillaceous rocks is the phyllosilicate mineral content. These minerals are particularly effective at binding metals to their surfaces by cation exchange and surface complexation. Generally, the magnitude of sorption is directly correlated with the phyllosilicate content (2:1 type clays: illite/smectite/illitesmectite mixed layers), and this parameter best reflects the sorption potential of a given mineral assembly. Consequently, sorption measurements on illite were preferably used as source data for the GR-SDB. The second component influencing radionuclide sorption is the porewater chemistry. In the present report, generic water compositions were extracted from the analytical ranges of deep ground waters in various sedimentary formations in Switzerland. In order to cover the range of ionic strength (I) and pH values of Swiss ground waters in argillaceous rocks, five types of generic water compositions were defined, combining low, intermediate and high values of ionic strength and pH. The GR-SDB for in situ conditions was derived using conversion factors (CF). As the name

  5. Transcriptome profiling during a natural host-parasite interaction.

    Science.gov (United States)

    McTaggart, Seanna J; Cézard, Timothée; Garbutt, Jennie S; Wilson, Phil J; Little, Tom J

    2015-08-28

    Infection outcome in some coevolving host-pathogens is characterised by host-pathogen genetic interactions, where particular host genotypes are susceptible only to a subset of pathogen genotypes. To identify candidate genes responsible for the infection status of the host, we exposed a Daphnia magna host genotype to two bacterial strains of Pasteuria ramosa, one of which results in infection, while the other does not. At three time points (four, eight and 12 h) post pathogen exposure, we sequenced the complete transcriptome of the hosts using RNA-Seq (Illumina). We observed a rapid and transient response to pathogen treatment. Specifically, at the four-hour time point, eight genes were differentially expressed. At the eight-hour time point, a single gene was differentially expressed in the resistant combination only, and no genes were differentially expressed at the 12-h time point. We found that pathogen-associated transcriptional activity is greatest soon after exposure. Genome-wide resistant combinations were more likely to show upregulation of genes, while susceptible combinations were more likely to be downregulated, relative to controls. Our results also provide several novel candidate genes that may play a pivotal role in determining infection outcomes.

  6. Characterisation and genome sequence of the lytic Acinetobacter baumannii bacteriophage vB_AbaS_Loki.

    Directory of Open Access Journals (Sweden)

    Dann Turner

    Full Text Available Acinetobacter baumannii has emerged as an important nosocomial pathogen in healthcare and community settings. While over 100 of Acinetobacter phages have been described in the literature, relatively few have been sequenced. This work describes the characterisation and genome annotation of a new lytic Acinetobacter siphovirus, vB_AbaS_Loki, isolated from activated sewage sludge. Sequencing revealed that Loki encapsulates a 41,308 bp genome, encoding 51 predicted open reading frames. Loki is most closely related to Acinetobacter phage IME_AB3 and more distantly related to Burkholderia phage KL1, Paracoccus phage vB_PmaS_IMEP1 and Pseudomonas phages vB_Pae_Kakheti25, vB_PaeS_SCH_Ab26 and PA73. Loki is characterised by a narrow host range, among the 40 Acinetobacter isolates tested, productive infection was only observed for the propagating host, A. baumannii ATCC 17978. Plaque formation was found to be dependent upon the presence of Ca2+ ions and adsorption to host cells was abolished upon incubation with a mutant of ATCC 17978 encoding a premature stop codon in lpxA. The complete genome sequence of vB_AbaS_Loki was deposited in the European Nucleotide Archive (ENA under the accession number LN890663.

  7. Ectoparasite diversity in the eastern rock sengis ( Elephantulus ...

    African Journals Online (AJOL)

    Ectoparasite diversity in the eastern rock sengis ( Elephantulus myurus ): the effect of seasonality and host sex. ... The ectoparasite assemblage comprised 11 groups of tick species, a single mite family, one louse and two flea species, with ticks and mites being the most numerous ectoparasites recovered. The prevalence ...

  8. Identification and Molecular Characterisation of a Novel Mu-Like Bacteriophage, SfMu, of Shigella flexneri.

    Directory of Open Access Journals (Sweden)

    Richa Jakhetia

    Full Text Available S. flexneri is the leading cause of bacillary dysentery in the developing countries. Several temperate phages originating from this host have been characterised. However, all S. flexneri phages known to date are lambdoid phages, which have the ability to confer the O-antigen modification of their host. In this study, we report the isolation and characterisation of a novel Mu-like phage from a serotype 4a strain of S. flexneri. The genome of phage SfMu is composed of 37,146 bp and is predicted to contain 55 open reading frames (orfs. Comparative genome analysis of phage SfMu with Mu and other Mu-like phages revealed that SfMu is closely related to phage Mu, sharing >90% identity with majority of its proteins. Moreover, investigation of phage SfMu receptor on the surface of the host cell revealed that the O-antigen of the host serves as the receptor for the adsorption of phage SfMu. This study also demonstrates pervasiveness of SfMu phage in S. flexneri, by identifying complete SfMu prophage strains of serotype X and Y, and remnants of SfMu in strains belonging to 4 other serotypes, thereby indicating that transposable phages in S. flexneri are not uncommon. The findings of this study contribute an advance in our current knowledge of S. flexneri phages and will also play a key role in understanding the evolution of S. flexneri.

  9. Characterisation of mineral deposition systems associated with rock art in the Kimberley region of northwest Australia.

    Science.gov (United States)

    Green, Helen; Gleadow, Andrew; Finch, Damien

    2017-10-01

    This data article contains mineralogical and chemical data from mineral accretions sampled from rock art shelters in the Kimberley region of north west Australia. The accretions were collected both on and off pigment and engraved rock art of varying styles observed in the Kimberley with an aim of providing a thorough understanding of the formation and preservation of such materials in the context of dating [1]. This contribution includes processed powder X-ray Diffraction data, Scanning Electron Microscopy energy dispersive spectroscopy data, and Laser Ablation ICP-MS trace element mapping data.

  10. Comparative geology and geochemistry of sedimentary-rock-hosted (Carlin Type) gold deposits in the People's Republic of China and in Nevada, USA

    Science.gov (United States)

    Li, Zhiping; Peters, Stephen G.

    1998-01-01

    Sedimentary-rock-hosted (Carlin-type) gold deposits have been considered economically significant and geologically distinct since the early 1960's. This report consists of a nine-part text and an interactive database. This small database is to help Western companies get more information about these gold deposits in China, and to help geologists who are interested in world Carlin-type deposits conduct research on them. Because of their economic significance and geological distinctiveness, these deposits have caught the interest of economic geologists all over the world since the early 1960's. Similar deposits have been discovered in China, Australia, Dominican Republic, Spain, and Russia besides Nevada. Perhaps most significant are the 165 Carlin-type gold deposits that were found in southwest China during the past 15 years. Of these, at least 19 deposits have proven to be of substantial tonnage, making China the second leading country to exploit such deposits. With the increasing interest in Chinese Carlin-type gold deposits, some western companies and geologists desire to get more information about these Chinese deposits. This seems to have been very difficult because the literature was in Chinese. It is estimated that several hundred scientific publications (including papers, books, and technical reports) have been published. This database of Chinese Carlin-type Gold deposits is built on the documentation published during the most recent 10 years and includes six subjects, which consist of 165 records and 30 fields. A new Proterozoic-age sedimentary-rock-hosted gold deposit in northeastern P.R. China also is described. Note that for the old version 1.1 on the CD-ROM, the latitude and longitude locations of the mineral occurrences have been estimated from sketch maps and journal articles and are not intended for digital analysis. One of the improvements in this version 1.2 is the accuracy of geographic data. Version 1.3 updates to the database and includes maps

  11. The Ruprechtov natural analogue site (Cz) study: mobile natural organic matter identification, characterisation and link to PA relevant processes - 16341

    International Nuclear Information System (INIS)

    Havlova, Vaclava; Cervinka, Radek; Noseck, Ulrich; Brasser, Thomas; Havel, Josef

    2009-01-01

    The Ruprechtov Natural Analogue (CZ) Programme has been focused on studying real system processes, relevant to performance assessment (PA) of sediment formations that can form the overburden of geological repository host rocks. The site has been extensively studied due to its geological constitution (granite - kaolin - clay - U mineralisation - organic matter). The presented study used Ruprechtov unique but well-described geological conditions in order to identify and characterise mobile organic matter (MOM) that can be easily released into groundwater and can influence PA relevant specie migration due to complexation/sorption reaction. The modem analytical method MALDI-TOF MS was used for characterisation. It was found that only a small fraction of sedimentary natural organic matter (NOM) from the site was easily releasable (max. 5%) as MOM, resulting in low organic substance concentration in natural groundwater. MOM amount released was decreasing with increasing NOM content. MALDI-TOF MS proved to be a useful tool to characterize organic substances, either natural ones or artificially released from natural organic matter samples. A noticeable fingerprint for all the MOM compounds analysed was found at MALDITOF MS spectra. This showed that MOM from the Ruprechtov site was in all cases composed of molecules with low molecular weight (under 1000 Da). As determined by the consequent geochemical analyses, despite groundwater reducing conditions MOM compounds would be mainly interacting with U(VI) in the groundwater, being present as more abundant U specie. Good correspondence of results enabled to consider the extracted humic acid HA 12/3 as a mobile organic matter fraction representative. (authors)

  12. Paleomagnetism and magnetic fabric of the Triassic rocks from Spitsbergen

    Science.gov (United States)

    Dudzisz, K.; Szaniawski, R.; Michalski, K.; Manby, G.

    2017-12-01

    Understanding the origin and directions of the natural remanent magnetization and the tectonic deformation pattern reflected in magnetic fabric is of importance for investigation of the West Spitsbergen Fold and Thrust Belt (WSFTB) and its foreland. Previous research carried out on Triassic rocks from the study area concluded that these rocks record a composite magnetization of both, normal and reverse polarity, consisting of a primary Triassic remanence that is overlapped by a secondary post-folding component. Standard paleomagnetic procedures were conducted in order to determine the remanence components and a low-field AMS was applied to assess the degree and pattern of deformation. The AMS results from the WSFTB reveal a magnetic foliation that parallels the bedding planes and a dominantly NNW-SSE oriented magnetic lineation that is sub-parallel to the regional fold axial trend. These results imply a low to moderate degree of deformation and a maximum strain orientation parallel to that of the fold belt. These data are consistent with an orthogonal convergence model for the WSFTB formation. In turn, the magnetic fabric on the undeformed foreland displays a distinct NNE-SSW orientation that we attribute to the paleocurrent direction. Rock-magnetic analyses reveal that the dominant ferrimagnetic carriers are magnetite and titanomagnetite. The Triassic rocks are characterised by complicated NRM patterns often with overlapping unblocking temperature spectra of particular components. The dominant magnetisation is characterised, however, by a steep inclination of 70-80º. The derived paleomagnetic direction from the WSFTB falls on the Jurassic - recent sector of the apparent polar wander path (APWP) of Baltica after tectonic unfolding. These data imply that at least some of the identified secondary components could have originated before the Eurekan folding event (K/Pg), for example, in Early Cretaceous time which corresponds to the period of rifting events on Barents

  13. The typology of Irish hard-rock aquifers based on an integrated hydrogeological and geophysical approach

    Science.gov (United States)

    Comte, Jean-Christophe; Cassidy, Rachel; Nitsche, Janka; Ofterdinger, Ulrich; Pilatova, Katarina; Flynn, Raymond

    2012-12-01

    Groundwater flow in hard-rock aquifers is strongly controlled by the characteristics and distribution of structural heterogeneity. A methodology for catchment-scale characterisation is presented, based on the integration of complementary, multi-scale hydrogeological, geophysical and geological approaches. This was applied to three contrasting catchments underlain by metamorphic rocks in the northern parts of Ireland (Republic of Ireland and Northern Ireland, UK). Cross-validated surface and borehole geophysical investigations confirm the discontinuous overburden, lithological compartmentalisation of the bedrock and important spatial variations of the weathered bedrock profiles at macro-scale. Fracture analysis suggests that the recent (Alpine) tectonic fabric exerts strong control on the internal aquifer structure at meso-scale, which is likely to impact on the anisotropy of aquifer properties. The combination of the interpretation of depth-specific hydraulic-test data with the structural information provided by geophysical tests allows characterisation of the hydrodynamic properties of the identified aquifer units. Regionally, the distribution of hydraulic conductivities can be described by inverse power laws specific to the aquifer litho-type. Observed groundwater flow directions reflect this multi-scale structure. The proposed integrated approach applies widely available investigative tools to identify key dominant structures controlling groundwater flow, characterising the aquifer type for each catchment and resolving the spatial distribution of relevant aquifer units and associated hydrodynamic parameters.

  14. Romanian experience with rock salt characterisation methods and the implications for disposal of spent nuclear fuel

    International Nuclear Information System (INIS)

    Diaconu, Daniela; Balan, Valeriu; Mirion, Ilie

    2001-01-01

    The disposal in deep geological formations as rock salt, granite or clay seems to be now the most appropriate solution for final storage of the spent fuel. At this moment, rock salt is one of the Romanian options for spent fuel disposal, but the final decision will be made only after a performance assessment of this geological formation, having as input data the specific characteristics of the salt rock. In order to provide the data requested by the safety assessment programs, the Institute for Nuclear Research - Pitesti developed complex and modern methodologies for thermodynamic parameter determination as well as studies on salt convergence and radionuclide migration. The methodologies pursued to determine those thermal properties specific for spent fuel disposal as dilatation coefficient, heat conductivity and specific heat. The convergence and migration studies pursued a better understanding of these processes, very important in the disposal safety. The paper is a review of those studies and presents the methodologies and the main results obtained on salt samples from Slanic Prahova Salt Mine. (authors)

  15. Petrographic and geochemical data for Cenozoic volcanic rocks of the Bodie Hills, California and Nevada

    Science.gov (United States)

    du Bray, Edward A.; John, David A.; Box, Stephen E.; Vikre, Peter G.; Fleck, Robert J.; Cousens, Brian L.

    2013-04-23

    Petrographic and geochemical data for Cenozoic volcanic rocks of the Bodie Hills, California and Nevada // // This report presents petrographic and geochemical data for samples collected during investigations of Tertiary volcanism in the Bodie Hills of California and Nevada. Igneous rocks in the area are principally 15–6 Ma subduction-related volcanic rocks of the Bodie Hills volcanic field but also include 3.9–0.1 Ma rocks of the bimodal, post-subduction Aurora volcanic field. Limited petrographic results for local basement rocks, including Mesozoic granitoid rocks and their metamorphic host rocks, are also included in the compilation. The petrographic data include visual estimates of phenocryst abundances as well as other diagnostic petrographic criteria. The geochemical data include whole-rock major oxide and trace element data, as well as limited whole-rock isotopic data.

  16. Hydrothermal modification of host rock geochemistry within Mo-Cu porphyry deposits in the Galway Granite, western Ireland

    Science.gov (United States)

    Tolometti, Gavin; McCarthy, Will

    2016-04-01

    Hydrothermal alteration of host rock is a process inherent to the formation of porphyry deposits and the required geochemical modification of these rocks is regularly used to indicate proximity to an economic target. The study involves examining the changes in major, minor and trace elements to understand how the quartz vein structures have influenced the chemistry within the Murvey Granite that forms part of the 380-425Ma Galway Granite Complex in western Ireland. Molybdenite mineralisation within the Galway Granite Complex occurred in close association with protracted magmatism at 423Ma, 410Ma, 407Ma, 397Ma and 383Ma and this continues to be of interest to active exploration. The aim of the project is to characterize hydrothermal alteration associated with Mo-Cu mineralisation and identify geochemical indicators that can guide future exploration work. The Murvey Granite intrudes metagabbros and gneiss that form part of the Connemara Metamorphic complex. The intrusion is composed of albite-rich pink granite, garnetiferous granite and phenocrytic orthoclase granite. Minor doleritic dykes post-date the Murvey Granite, found commonly along its margins. Field mapping shows that the granite is truncated to the east by a regional NW-SE fault and that several small subparallel structures host Mo-Cu bearing quartz veins. Petrographic observations show heavily sericitized feldspars and plagioclase and biotite which have undergone kaolinization and chloritisation. Chalcopyrite minerals are fine grained, heavily fractured found crystallized along the margins of the feldspars and 2mm pyrite crystals. Molybdenite are also seen along the margins of the feldspars, crystallized whilst the Murvey Granite cooled. Field and petrographic observations indicate that mineralisation is structurally controlled by NW-SE faults from the selected mineralization zones and conjugate NE-SW cross cutting the Murvey Granite. Both fault orientations exhibit quartz and disseminated molybdenite

  17. Do Hf isotopes in magmatic zircons represent those of their host rocks?

    Science.gov (United States)

    Wang, Di; Wang, Xiao-Lei; Cai, Yue; Goldstein, Steven L.; Yang, Tao

    2018-04-01

    Lu-Hf isotopic system in zircon is a powerful and widely used geochemical tracer in studying petrogenesis of magmatic rocks and crustal evolution, assuming that zircon Hf isotopes can represent initial Hf isotopes of their parental whole rock. However, this assumption may not always be valid. Disequilibrium partial melting of continental crust would preferentially melt out non-zircon minerals with high time-integrated Lu/Hf ratios and generate partial melts with Hf isotope compositions that are more radiogenic than those of its magma source. Dissolution experiments (with hotplate, bomb and sintering procedures) of zircon-bearing samples demonstrate this disequilibrium effect where partial dissolution yielded variable and more radiogenic Hf isotope compositions than fully dissolved samples. A case study from the Neoproterozoic Jiuling batholith in southern China shows that about half of the investigated samples show decoupled Hf isotopes between zircons and the bulk rocks. This decoupling could reflect complex and prolonged magmatic processes, such as crustal assimilation, magma mixing, and disequilibrium melting, which are consistent with the wide temperature spectrum from ∼630 °C to ∼900 °C by Ti-in-zircon thermometer. We suggest that magmatic zircons may only record the Hf isotopic composition of their surrounding melt during crystallization and it is uncertain whether their Hf isotopic compositions can represent the primary Hf isotopic compositions of the bulk magmas. In this regard, using zircon Hf isotopic compositions to trace crustal evolution may be biased since most of these could be originally from disequilibrium partial melts.

  18. THE STUDY OF GAS MIGRATION IN CRYSTALLINE ROCK USING INJECTION TESTS

    Directory of Open Access Journals (Sweden)

    Jiří Svoboda

    2012-07-01

    Full Text Available The study of gas migration in crystalline rock using injection tests is being carried out in the frame of the FORGE (Fate of Repository Gases project. The Czech Technical University in Prague (CTU, Centre of Experimental Geotechnics (CEG is participating in WP4 which is focused on disturbed host rock formations with respect to radioactive waste deep repositories. A series of in-situ tests is being conducted at the Josef Underground Laboratory. The aim of the testing is to simulate and study phenomena that might lead to gas-driven radionuclide transport in fractured crystalline rock. The in-situ tests combine migration and large-scale gas injection measurements; gas injection tests are being employed for the study of gas transport. For the purposes of comparison of the behaviour of the rock mass with regard to air and water a series of water pressure tests are also being carried out. The quality of the rock mass is assessed using rock mass classification systems.

  19. Rock Mechanics Forsmark. Site descriptive modelling Forsmark stage 2.2

    Energy Technology Data Exchange (ETDEWEB)

    Glamheden, Rune; Fredriksson, Anders (Golder Associates AB (SE)); Roeshoff, Kennert; Karlsson, Johan (Berg Bygg Konsult AB (SE)); Hakami, Hossein (Itasca Geomekanik AB (SE)); Christiansson, Rolf (Swedish Nuclear Fuel and Waste Management Co., Stockholm (SE))

    2007-12-15

    The Swedish Nuclear Fuel and Waste Management Company (SKB) is undertaking site characterisation at two different locations, Forsmark and Laxemar/Simpevarp, with the objective of siting a geological repository for spent nuclear fuel. The characterisation of a site is an integrated work carried out by several disciplines including geology, rock mechanics, thermal properties, hydrogeology, hydrogeochemistry and surface systems. This report presents the rock mechanics model of the Forsmark site up to stage 2.2. The scope of work has included compilation and analysis of primary data of intact rock and fractures, estimation of the rock mass mechanical properties and estimation of the in situ state of stress at the Forsmark site. The laboratory results on intact rock and fractures in the target volume demonstrate a good quality rock mass that is strong, stiff and relatively homogeneous. The homogeneity is also supported by the lithological and the hydrogeological models. The properties of the rock mass have been initially estimated by two separate modelling approaches, one empirical and one theoretical. An overall final estimate of the rock mass properties were achieved by integrating the results from the two models via a process termed 'Harmonization'. Both the tensile tests, carried out perpendicular and parallel to the foliation, and the theoretical analyses of the rock mass properties in directions parallel and perpendicular to the major principal stress, result in parameter values almost independent of direction. This indicates that the rock mass in the target volume is isotropic. The rock mass quality in the target volume appears to be of high and uniform quality. Those portions with reduced rock mass quality that do exist are mainly related to sections with increased fracture frequency. Such sections are associated with deformation zones according to the geological description. The results of adjacent rock domains and fracture domains of the target

  20. Summary of rock mechanics work completed for Posiva before 2005

    International Nuclear Information System (INIS)

    Hudson, J.A.; Johansson, E.

    2006-06-01

    To plan Posiva's rock mechanics work for 2005-2006 and beyond, it was necessary to have a clear understanding of the individual components of work that had been completed for Posiva before 2005 and to assess the cumulative rock mechanics knowledge base. This review summarizes the 80 individual completed documents, which include rock mechanics reports and other reports containing rock mechanics material. They are summarised within a structured framework of rock properties, analyses and the effects of excavation. Following the introductory section, the method of structuring the rock mechanics information is presented. Then the tabulation highlighting the features of all the previous rock mechanics work is explained. This tabulation forms the Appendix; the content of each rock mechanics report that has been produced is summarized via the table headings of document number, subject area, document reference, subject matter, objectives, methodology, highlighted figures, conclusions and comments. In addition to the direct usefulness of the tabulation in summarizing each report, it has been possible to draw overall conclusions: Information has also been obtained worldwide, especially Sweden and Canada; The rock stress state has been measured but further work is required related both to in situ measurements and numerical modelling to study, e.g., the influence of deformation zones on the local stress state; The intact rock has been extensively studied: there is a good knowledge of the parameters and their values, including the anisotropic nature of the site rocks; The geometry of the fractures is included in the geological characterisation but more rock mechanics work is required on the mechanical properties; The mechanical properties of the deformation zones have not been studied in detail; The thermal properties of the site rock are relatively well understood; A new classification has been developed for constructability and long-term safety assessment. This classification

  1. Measured sections and analyses of uranium host rocks of the Dockum Group, New Mexico and Texas

    International Nuclear Information System (INIS)

    Dickson, R.E.; Drake, D.P.; Reese, T.J.

    1977-02-01

    This report presents 27 measured sections from the Dockum Group of Late Triassic age, in the southern High Plains of eastern New Mexico and northwestern Texas. Many of the measured sections are only partial; the intent in those cases was to measure the parts of sections that had prominent sandstone/conglomerate beds or that had uranium deposits. No attempt was made to relate rock color to a rock color chart; rock colors are therefore approximate. Modal analyses (by thin-section examination) of sandstone and conglomerate samples and gamma-ray spectrometric analyses of the samples are presented in appendices

  2. Burial history of two potential clay host formations in Belgium

    International Nuclear Information System (INIS)

    Mertens, J.; Wouters, L.; Van Marcke, Ph.

    2004-01-01

    When dealing with long term stability of repository host rocks, it is important to consider and learn from all past geological events since the deposition of the formations. The burial history of the Boom Clay and Ypresian Clays, both considered as potential host rocks in Belgium, illustrates that the North Belgian region was tectonically relatively stable since deposition. In Northern Belgium, where both formations are located at a few hundreds meters of depth, tectonic movements were relatively small and no significant uplifts took place. The burial history of the Boom Clay in Mol, where the HADES underground research facility is located illustrates this. On the poster, the burial history for both formations is presented at two locations each: one location in the outcrop region and one research site location, where the formation is currently buried under a few 100 metres of sediment. (authors)

  3. Did the Kiruna iron ores form as a result of a metasomatic or igneous process? New U-Pb and Nd data for the iron oxide apatite ores and their host rocks in the Norrbotten region of northern Sweden

    Science.gov (United States)

    Westhues, A.; Hanchar, J. M.; Whitehouse, M. J.; Fisher, C. M.

    2012-12-01

    A number of iron deposits near Kiruna in the Norrbotten region of northern Sweden are of the iron oxide apatite (IOA) type of deposits; also referred to as Kiruna-type deposits. They are commonly considered a subgroup or end-member of iron oxide copper gold (IOCG) deposits, containing no economic grades of copper or gold. Both IOCG and IOA deposits are characterized by abundant low-Ti Fe oxides, an enrichment in REE, and intense sodium and potassium wall-rock alteration adjacent to the ores. Deposits of these types are of a great economic importance, not only for iron, but also for other elements such as rare earth elements (REE) or uranium. Kiruna, the type locality of the IOA type of mineral deposits, is the focus of this study. Despite a century-long mining history and 2500 Mt of iron ore produced in the region to date (with grades of 30 to 70 wt.% Fe), the genesis of these deposits is poorly understood: theories of a magmatic vs. a hydrothermal or metasomatic origin have been debated, and the timing of mineralization of the ores in the Norbotten region has never been directly dated. The results anticipated from this study will provide a better understanding of the nature of the IOA type of mineral deposits and their relation to IOCG deposits such as Olympic Dam in Australia. An array of geochemical methods is used in order to gain insights on the emplacement history of the host rocks, their subsequent alteration, and the ore genesis of these deposits. This includes in situ U/Pb geochronology of zircon, monazite, and titanite to constrain the timing between host rock emplacement, alteration and mineralization. Isotopic data from whole rocks and in situ at mineral scale will provide constraints on the involvement of hydrothermal fluids and their possible sources, as well as on the sources of Fe, U, and the REE. Newly obtained Sm-Nd isotopic data points to distinct source differences between host rocks, ore and alteration related samples. Preliminary in situ U

  4. The origin of groundwater salinity in granitic rocks: identification and characterisation of chloride sources; Origine de la salinite des eaux souterraines en milieu granitique: identification et caracterisation des sources de chlorure

    Energy Technology Data Exchange (ETDEWEB)

    Savoye, S.

    1998-04-29

    Hydrogeological research in crystalline rocks, developed either in geothermics or in feasibility studies for geological disposal of radioactive waste, points out a wide range of chloride contents in associated groundwaters. The aim of this dissertation is to identify the possible origins of chloride in groundwaters within different geological conditions. The three possible chloride reservoirs (chloride-bearing minerals, fluid inclusions, micro-porosity) located in rock have been characterised by studying samples from eight granitic sites with different technical approaches (electronic microbeam, alkaline fusion, micro-thermometry, crush-leaching, diffusion experiment). Firstly, this allows the definition of a new typology of the sites, by considering not only hydrogeological features but also occurrence of salt-rich fluid inclusions with sedimentary origin. Secondly, the use of tracers (such as Cl/Br ratio, {delta}{sup 37}Cl) and mass balance calculations shows that the contribution of fluid inclusions trapped in quartz and chloride-bearing minerals cannot account for the high salinity of groundwater. In this case, the chloride origin could be of sedimentary type. Chloride would be stored in micro-porosity and in fluid inclusions trapped in carbonates. Thirdly, we have pointed out the importance of micro-porosity, acting more as a sieve and a buffer than as a source. Finally, we have shown that the low salinity of groundwaters has not always an internal origin. (author) 187 refs.

  5. Review of potential host rocks for radioactive waste disposal in the Piedmont Province of Virginia and Maryland

    International Nuclear Information System (INIS)

    Brown, W.R.

    1980-10-01

    This study is a detailed follow-up of a broad study of the Southeastern Piedmont by Acres American, Inc. (1978) based upon literature and existing knowledge. The purpose is to designate broad areas in which the rock type is favorable for field exploration for the possible designation of a site for disposal of solidified radioactive waste. The Acres study classified rock units as favorable, potentially favorable, and unfavorable. The objective of the present study is: (1) to review the criteria used in this classification, and (2) on the basis of a detailed knowledge of local rock units to reassign the rock types in the potentially favorable category to either the favorable or the unfavorable categories. As in the Acres study, the objective is to designate field study areas, not potential sites. This study was based entirely upon a literature study, discussions with persons knowledgeable of the region, and a personal acquaintance with the rocks and structures. No field work was done specifically for this project. No consideration was given to sociological, economic, or non-technical factors

  6. Propolis volatiles characterisation from acaricide-treated and -untreated beehives maintained at Algarve (Portugal).

    Science.gov (United States)

    Miguel, Maria G; Nunes, Susana; Cruz, Cláudia; Duarte, João; Antunes, Maria D; Cavaco, Ana M; Mendes, Marta D; Lima, A Sofia; Pedro, Luis G; Barroso, José G; Figueiredo, A Cristina

    2013-04-01

    The variability of the volatile profile of 70 propolis samples from acaricide-treated and -untreated beehives maintained at Algarve (Portugal) was evaluated. Propolis samples were collected in three regions of Algarve at three different periods. Cluster analysis based on the propolis volatiles' chemical composition defined two main clusters, not related to the time of year, collection site, altitude, temperature or humidity ranges, and was based mainly on the relative amounts of viridiflorol, n-tricosane and n-nonadecane for cluster I. Cluster II was mainly characterised by the high thymol content, followed by viridiflorol, n-tricosane and n-nonadecane. The presence of higher thymol levels in propolis samples from cluster II may reflect the long use of an acaricide with thymol as main active ingredient. All samples showed an intense rock-rose aroma supported by the presence of characteristic Cistus and labdanum oil volatile components. Given the nowadays frequent propolis household use, volatiles thorough characterisation may assist in its quality assessment.

  7. Structural and geochemical techniques for the hydrogeological characterisation and stochastic modelling of fractured media

    International Nuclear Information System (INIS)

    Vela, A.; Elorza, F.J.; Florez, F.; Paredes, C.; Mazadiego, L.; Llamas, J.F.; Perez, E.; Vives, L.; Carrera, J.; Munoz, A.; De Vicente, G.; Casquet, C.

    1999-01-01

    Safety analysis of radioactive waste storage systems require fractured rock studies. The performance assessment studies of this type of problems include the development of radionuclide flow and transport models to predict the evolution of possible contaminants released from the repository to the biosphere. The methodology developed in the HIDROBAP project and some results obtained with its application in El Berrocal granite batholith are presented. It integrates modern tools belonging to different disciplines. A Discrete Fracture Network model (DFT) was selected to simulate the fractured medium and a 3D finite element flow and transport model that includes the inverse problem techniques has been coupled to the DFT model to simulate the water movement trough the fracture network system. Preliminary results show that this integrated methodology can be very useful for the hydrogeological characterisation of rock fractured media. (author)

  8. Uranium and thorium abundances in some graphite-bearing precambrian rocks of India and implications

    International Nuclear Information System (INIS)

    Pandey, U.K.; Krishnamurthy, P.

    1995-01-01

    Graphite schists from parts of Gujarat in the Aravalli supergroup show maximum contents of uranium (70-95 ppm), hosted mainly in the graphites, whereas such schists from the Tamil Nadu granulite terrain contain distinctly lower amounts of uranium (7-9 ppm). Graphite-bearing hornblende gneiss and calc-granulites from Madurai, Tamil Nadu, contain higher amounts of uranium (12-28 ppm) than the schists, and uranium is mainly hosted by the magnetite and allanite occurring as independent grains with flaky graphite and also as inclusions within quartz. Khondalites from Andhra Pradesh are depleted in uranium (0.9-1.3 ppm) compared to Th (17.5-20.2 ppm). Except for the khondalites, which have high Th/U ratio (13.5-22.4), all the other samples have very low Th/U ratios (0.10-0.80) compared to the crustal average (3-4). Such variations among similar rock types, may in part be related to uranium and thorium abundances inherited from parental rocks, modified later by hydrothermal and/or metasomatic processes. Graphites from such rock types can provide both in situ and migrant reductants for hosting a variety of uranium and other metallic deposits. (author). 12 refs., 1 tab., 1 fig

  9. Fifteen years of microbiological investigation in Opalinus Clay at the Mont Terri rock laboratory (Switzerland)

    Energy Technology Data Exchange (ETDEWEB)

    Leupin, O.X. [National Cooperative for the Disposal of Radioactive Waste (NAGRA), Wettingen (Switzerland); Bernier-Latmani, R.; Bagnoud, A. [Swiss Federal Office of Technology EPFL, Lausanne (Switzerland); Moors, H.; Leys, N.; Wouters, K. [Belgian Nuclear Research Centre SCK-CEN, Mol (Belgium); Stroes-Gascoyne, S. [University of Saskatchewan, Saskatoon (Canada)

    2017-04-15

    Microbiological studies related to the geological disposal of radioactive waste have been conducted at the Mont Terri rock laboratory in Opalinus Clay, a potential host rock for a deep geologic repository, since 2002. The metabolic potential of microorganisms and their response to excavation-induced effects have been investigated in undisturbed and disturbed claystone cores and in pore- (borehole) water. Results from nearly 15 years of research at the Mont Terri rock laboratory have shown that microorganisms can potentially affect the environment of a repository by influencing redox conditions, metal corrosion and gas production and consumption under favourable conditions. However, the activity of microorganisms in undisturbed Opalinus Clay is limited by the very low porosity, the low water activity, and the largely recalcitrant nature of organic matter in the claystone formation. The presence of microorganisms in numerous experiments at the Mont Terri rock laboratory has suggested that excavation activities and perturbation of the host rock combined with additional contamination during the installation of experiments in boreholes create favourable conditions for microbial activity by providing increased space, water and substrates. Thus effects resulting from microbial activity might be expected in the proximity of a geological repository i.e., in the excavation damaged zone, the engineered barriers, and first containments (the containers). (authors)

  10. Fifteen years of microbiological investigation in Opalinus Clay at the Mont Terri rock laboratory (Switzerland)

    International Nuclear Information System (INIS)

    Leupin, O.X.; Bernier-Latmani, R.; Bagnoud, A.; Moors, H.; Leys, N.; Wouters, K.; Stroes-Gascoyne, S.

    2017-01-01

    Microbiological studies related to the geological disposal of radioactive waste have been conducted at the Mont Terri rock laboratory in Opalinus Clay, a potential host rock for a deep geologic repository, since 2002. The metabolic potential of microorganisms and their response to excavation-induced effects have been investigated in undisturbed and disturbed claystone cores and in pore- (borehole) water. Results from nearly 15 years of research at the Mont Terri rock laboratory have shown that microorganisms can potentially affect the environment of a repository by influencing redox conditions, metal corrosion and gas production and consumption under favourable conditions. However, the activity of microorganisms in undisturbed Opalinus Clay is limited by the very low porosity, the low water activity, and the largely recalcitrant nature of organic matter in the claystone formation. The presence of microorganisms in numerous experiments at the Mont Terri rock laboratory has suggested that excavation activities and perturbation of the host rock combined with additional contamination during the installation of experiments in boreholes create favourable conditions for microbial activity by providing increased space, water and substrates. Thus effects resulting from microbial activity might be expected in the proximity of a geological repository i.e., in the excavation damaged zone, the engineered barriers, and first containments (the containers). (authors)

  11. Characterizing Excavation Damaged Zone and Stability of Pressurized Lined Rock Caverns for Underground Compressed Air Energy Storage

    Science.gov (United States)

    Kim, Hyung-Mok; Rutqvist, Jonny; Jeong, Ju-Hwan; Choi, Byung-Hee; Ryu, Dong-Woo; Song, Won-Kyong

    2013-09-01

    In this paper, we investigate the influence of the excavation damaged zone (EDZ) on the geomechanical performance of compressed air energy storage (CAES) in lined rock caverns. We conducted a detailed characterization of the EDZ in rock caverns that have been excavated for a Korean pilot test program on CAES in (concrete) lined rock caverns at shallow depth. The EDZ was characterized by measurements of P- and S-wave velocities and permeability across the EDZ and into undisturbed host rock. Moreover, we constructed an in situ concrete lining model and conducted permeability measurements in boreholes penetrating the concrete, through the EDZ and into the undisturbed host rock. Using the site-specific conditions and the results of the EDZ characterization, we carried out a model simulation to investigate the influence of the EDZ on the CAES performance, in particular related to geomechanical responses and stability. We used a modeling approach including coupled thermodynamic multiphase flow and geomechanics, which was proven to be useful in previous generic CAES studies. Our modeling results showed that the potential for inducing tensile fractures and air leakage through the concrete lining could be substantially reduced if the EDZ around the cavern could be minimized. Moreover, the results showed that the most favorable design for reducing the potential for tensile failure in the lining would be a relatively compliant concrete lining with a tight inner seal, and a relatively stiff (uncompliant) host rock with a minimized EDZ. Because EDZ compliance depends on its compressibility (or modulus) and thickness, care should be taken during drill and blast operations to minimize the damage to the cavern walls.

  12. Aluminium phosphate sulphate minerals (APS) associated with proterozoic unconformity-type uranium deposits: crystal-chemical characterisation and petrogenetic significance

    International Nuclear Information System (INIS)

    Gaboreau, St.

    2005-01-01

    Aluminium phosphate sulfate minerals (APS) are particularly widespread and spatially associated with hydrothermal clay alteration in both the East Alligator River Uranium Field (Northern Territory, Australia) and the Athabasca basin (Saskatchewan, Canada), in the environment of proterozoic unconformity-related uranium deposits (URUD). The purpose of this study is both: 1) to characterize the nature and the origin of the APS minerals on both sides of the middle proterozoic unconformity between the overlying sandstones and the underlying metamorphic basement rocks that host the uranium ore bodies, 2) to improve our knowledge on the suitability of these minerals to indicate the paleo-conditions (redox, pH) at which the alteration processes relative to the uranium deposition operated. The APS minerals result from the interaction of oxidising and relatively acidic fluids with aluminous host rocks enriched in monazite. Several APS-bearing clay assemblages and APS crystal-chemistry have also been distinguished as a function of the distance from the uranium ore bodies or from the structural discontinuities which drained the hydrothermal solutions during the mineralisation event. One of the main results of this study is that the index mineral assemblages, used in the recent literature to describe the alteration zones around the uranium ore bodies, can be theoretically predicted by a set of thermodynamic calculations which simulate different steps of fluid-rock interaction processes related to a downward penetrating of hyper-saline, oxidizing and acidic diagenetic fluids through the lower sandstone units of the basins and then into the metamorphic basement rocks. The above considerations and the fact that APS with different crystal-chemical compositions crystallized in a range of fO 2 and pH at which uranium can either be transported in solution or precipitated as uraninite in the host-rocks make these minerals not only good markers of the degree of alteration of the

  13. Multi-element analysis of emeralds and associated rocks by k0 neutron activation analysis

    International Nuclear Information System (INIS)

    Acharya, R.N.; Mondal, R.K.; Burte, P.P.; Nair, A.G.C.; Reddy, N.B.Y.; Reddy, L.K.; Reddy, A.V.R.; Manohar, S.B.

    2000-01-01

    Multi-element analysis was carried out in natural emeralds, their associated rocks and one sample of beryl obtained from Rajasthan, India. The concentrations of 21 elements were assayed by Instrumental Neutron Activation Analysis using the k 0 method (k 0 INAA method) and high-resolution gamma ray spectrometry. The data reveal the segregation of some elements from associated (trapped and host) rocks to the mineral beryl forming the gemstones. A reference rock standard of the US Geological Survey (USGS BCR-1) was also analysed as a control of the method

  14. Natural analogs in the host rock salt. Pt. 1. General study (2011). Pt. 2. Detail studies (2012-2013); Natuerliche Analoga im Wirtsgestein Salz. T. 1. Generelle Studie (2011). T. 2. Detailstudien (2012-2013)

    Energy Technology Data Exchange (ETDEWEB)

    Brasser, Thomas; Fahrenholz, Christine; Kull, Herbert; Meleshyn, Artur; Moenig, Heike; Noseck, Ulrich; Schoenwiese, Dagmar; Wolf, Jens

    2014-12-15

    The first part of the project ISIBELII on natural analogs in the host rock salt included a summary of available studies on the topic to be used in a safety analysis for a final repository for heat generating radioactive waste. In 2012 the results of the preliminary safety analysis Gorleben was available, including results on the fracturing of anhydrite, the formation of cryogenic gaps and the influence of earthquakes. The requirements for the barrier system have been modified due to the safety requirements for the final disposal of heat-generating radioactive wastes valid since 2010. For containers the functionality gas to be demonstrated for 500 years. The following issues are covered: natural analogs for the integrity demonstration of the geological barrier, natural analogs for the integrity demonstration of geotechnical barriers, natural analogs for the evaluation of release scenarios. The detail studies include anhydrite fracturing, salt grit compaction, chemical composition of fluid inclusions, thermal stability of salt rock, mechanical stability of salt rock, influence of earthquakes, qualified closures, iron corrosion, and microbial processes.

  15. Aespoe hard rock laboratory. Annual report 2000

    International Nuclear Information System (INIS)

    2001-06-01

    The Aespoe Hard Rock Laboratory constitutes an important component of SKB's work to design, construct, and implement a deep geological repository for spent nuclear fuel and to develop and test methods for characterisation of selected repository sites. The retention effect of the rock has been studied by tracer tests in the Tracer Retention Understanding Experiments (TRUE) and the TRUE Block Scale (TRUE BS). These tests are supplemented by the new Long Term Diffusion Experiment (LTDE). During year 2000 the field experiments of TRUE BS (50 m scale) were completed and preparations made for the LTDE (migration through a fracture wall and into the rock), including boring of approximately 10 m deep hole with 300 mm diameter. Laboratory investigations have difficulties in simulating natural conditions and need supplementary field studies to support validation exercises. A special borehole probe, CHEMLAB, has therefore been designed for different kinds of validation experiments where data can be obtained representative for the in-situ properties of groundwater at repository depth. During 2000 migration experiments were made with actinides (Am, Np and Pu) in CHEMLAB 2, the simplified supplement to CHEMLAB 1. Colloids of nuclides as well as of bentonite might affect the migration of released radionuclides and a separate project was planned during 2000 to assess the existence, stability and mobility of colloids. The development of numerical modelling tools continues with the general objective to improve the numerical models in terms of flow and transport and to update the site-scale and laboratory scale models for the Aespoe HRL. The Matrix Fluid Chemistry project aims at determining the origin and age of matrix fluids and the experiment has been designed to sample matrix fluids from predetermined, isolated borehole sections by specialised equipment. The Aespoe HRL also has the task to demonstrate and perform full scale tests of the function of different components of the

  16. Geomass: geological modelling analysis and simulation software for the characterisation of fractured hard rock environments

    International Nuclear Information System (INIS)

    White, M.J.; Humm, J.P.; Todaka, N.; Takeuchi, S.

    1998-01-01

    This paper presents the development and functionality of a suite of applications which are being developed to support the geological investigations in the Tono URL. GEOMASS will include 3D geological modelling, 3D fluid flow and solute transport and 3D visualisation capabilities. The 3D geological modelling in GEOMASS will be undertaken using a commercially available 3D geological modelling system, EarthVision. EarthVision provides 3D mapping, interpolation, analysis and well planning software. It is being used in the GEOMASS system to provide the geological framework (structure of the tectonic faults and stratigraphic and lithological contacts) to the 3D flow code. It is also being used to gather the geological data into a standard format for use throughout the investigation programme. The 3D flow solver to be used in GEOMASS is called Frac-Affinity. Frac-Affinity models the 3D geometry of the flow system as a hybrid medium, in which the rock contains both permeable, intact rock and fractures. Frac-Affinity also performs interpolation of heterogeneous rock mass property data using a fractal based approach and the generation of stochastic fracture networks. The code solves for transient flow over a user defined sub-region of the geological framework supplied by EarthVision. The results from Frac-Affinity are passed back to EarthVision so that the flow simulation can be visualized alongside the geological structure. This work-flow allows rapid assessment of the role of geological features in controlling flow. This paper will present the concepts and approach of GEOMASS and illustrate the practical application of GEOMASS using data from Tono

  17. Some antarctic soil cores from Wood Bay characterised by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Bertelle, M.; Leotta, G.; Calogero, S.; Constantinescu, S.; Oddone, M.

    1999-01-01

    Marine, lacustrine and terrestrial soil cores, sampled in a restricted area of Wood Bay in Antarctica, were characterised by 57 Fe Moessbauer spectroscopy. The results of X-ray diffraction and instrumental neutron activation analysis are shortly discussed too. The soils, formed by mechanical disaggregation and weathering of rocks of volcanic origin from Mt. Melbourne, consist of alkaline feldspars, olivines, augitic clinopyroxenes, and iron oxides such as haematite, goethite, and magnetite. Lacustrine and terrestrial soils are richer in clinopyroxenes whereas marine soils are richer in olivines. This finding shows that the soils retain a content in olivines and clinopyroxenes comparable to that found in the parent lava outcropped from Mt. Melbourne volcano. The soils appear at the initial stage of weathering. Two main weathering effects are observed: 1. atmospheric oxygen determines the oxidation of the iron(II) present in olivines and clinopyroxenes and the neo-formed iron(III) is mainly retained in silicate sites as structural iron(III); 2. a part of magnetite, present as a primary constituent of the volcanic rocks, is oxidised to bulk haematite and goethite. (authors)

  18. Aespoe Hard Rock Laboratory. Status Report May - August 2009

    International Nuclear Information System (INIS)

    2009-11-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2009/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period May to August 2009

  19. Aespoe Hard Rock Laboratory. Status Report October - December 2008

    International Nuclear Information System (INIS)

    2009-03-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2008/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the fourth quarter of 2008

  20. Aespoe Hard Rock Laboratory. Status Report. September - December 2009

    International Nuclear Information System (INIS)

    2010-05-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2009/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period September to December 2009

  1. Aespoe Hard Rock Laboratory. Status Report January - April 2009

    International Nuclear Information System (INIS)

    2009-09-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2009/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period January to April 2009

  2. Aespoe Hard Rock Laboratory. Status Report. April - June 2007

    Energy Technology Data Exchange (ETDEWEB)

    2007-07-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2005- 2010 are presented in SKB's RDandD-Programme 2004 /SKB 2004/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2007/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the second quarter 2007

  3. Aespoe Hard Rock Laboratory. Status Report. April - June 2007

    International Nuclear Information System (INIS)

    2007-01-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2005- 2010 are presented in SKB's RDandD-Programme 2004 /SKB 2004/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2007/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the second quarter 2007

  4. Aespoe Hard Rock Laboratory. Status Report. July - September 2008

    International Nuclear Information System (INIS)

    2008-01-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2008/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the third quarter of 2008

  5. Aespoe Hard Rock Laboratory. Status Report. January - April 2010

    International Nuclear Information System (INIS)

    2010-10-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2009/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period January to April 2010

  6. Evolution of Th and U whole-rock contents in the Ilimaussaq intrusion

    International Nuclear Information System (INIS)

    Bailey, J.C.; Rose-Hansen, J.; Soerensen, H.

    1981-01-01

    Thorium and uranium values of a large collction of representative samples taken from all rock types of the Ilimaussaq alkaline intrusion, South Greenland, are presented. The values are largely obtained by laboratory gamma-ray spectrometric (GRS) analysis. The results are discussed in relation to current knowledge and ideas on the petrologic evolution of the Ilimaussaq intrusion. It is concluded that (1) Rocks from the Ilimaussaq alkaline intrusion evolve to extremely high Th and U contents; (2) The evolution is characterised by appearance of low-Th/U cumulates due to the appearance of low-Th/U eudialyte as a liquidus phase; (3) Fractionation of the observed cumulus assemblages fails to explain all features of the Th-U evolution; (4) Losses of mobile fluids, rich in Th/U, occur in the final stages. (BP)

  7. Basic rock properties for the thermo-hydro-mechanical analysis of a high-level radioactive waste repository

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jhin Wung; Kang, Chul Hyung

    1999-04-01

    Deep geological radioactive waste disposal is generally based on the isolation of the waste from the biosphere by multiple barriers. The host rock is one of these barriers which should provide a stable mechanical and chemical environment for the engineered barriers. In the evaluation of the safety of the high-level radioactive waste disposal systems, an important part of the safety analysis is an assessment of the coupling or interaction between thermal, hydrological, and mechanical effects. In order to do this assessment, adequate data on the characteristics of different host rocks are necessary. The properties of the rock and rock discontinuity are very complex and their values vary in a wide range. The accuracy of the result of the assessment depends on the values of these properties used. The present study is an attempt to bring together and condense data for the basic properties of various rock masses, which are needed in the thermo-hydro-mechanical analysis for the deep geological radioactive waste repository. The testing and measurement methods for these basic properties are also presented. Domestic data for deep geological media should be supplemented in the future, due to the insufficiency and the lack of accuracy of the data available at present. (author). 28 refs., 21 figs.

  8. Basic rock properties for the thermo-hydro-mechanical analysis of a high-level radioactive waste repository

    International Nuclear Information System (INIS)

    Kim, Jhin Wung; Kang, Chul Hyung

    1999-04-01

    Deep geological radioactive waste disposal is generally based on the isolation of the waste from the biosphere by multiple barriers. The host rock is one of these barriers which should provide a stable mechanical and chemical environment for the engineered barriers. In the evaluation of the safety of the high-level radioactive waste disposal systems, an important part of the safety analysis is an assessment of the coupling or interaction between thermal, hydrological, and mechanical effects. In order to do this assessment, adequate data on the characteristics of different host rocks are necessary. The properties of the rock and rock discontinuity are very complex and their values vary in a wide range. The accuracy of the result of the assessment depends on the values of these properties used. The present study is an attempt to bring together and condense data for the basic properties of various rock masses, which are needed in the thermo-hydro-mechanical analysis for the deep geological radioactive waste repository. The testing and measurement methods for these basic properties are also presented. Domestic data for deep geological media should be supplemented in the future, due to the insufficiency and the lack of accuracy of the data available at present. (author). 28 refs., 21 figs

  9. Rock mechanics in the National Waste Terminal Storage Program

    International Nuclear Information System (INIS)

    Monsees, J.E.; Wigley, M.R.

    1982-01-01

    The overall objective of the rock mechanics program of the Office of Nuclear Waste Isolation is to predict the response of a rock mass hosting a waste repository during its construction, operation, and postoperational phases. The operational phase is expected to be 50 to 100 yr; the postoperational phase will last until the repository no longer poses any potential hazard to the biosphere, a period that may last several thousand years. The rock mechanics program is concerned with near-field effects on mine stability, as well as far-field effects relative to the overall integrity of the geologic waste isolation system. To accomplish these objectives, the rock mechanics program has established interactive studies in numerical simulation, laboratory testing, and field testing. The laboratory and field investigations provide input to the numerical simulations and give an opportunity for verification and validation of the predictive capabilities of the computer codes. Ultimately the computer codes will be used to predict the response of the geologic system to the development of a repository. 3 references, 5 figures

  10. Multi-element analysis of emeralds and associated rocks by k{sub 0} neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Acharya, R.N.; Mondal, R.K.; Burte, P.P.; Nair, A.G.C.; Reddy, N.B.Y.; Reddy, L.K.; Reddy, A.V.R.; Manohar, S.B

    2000-12-15

    Multi-element analysis was carried out in natural emeralds, their associated rocks and one sample of beryl obtained from Rajasthan, India. The concentrations of 21 elements were assayed by Instrumental Neutron Activation Analysis using the k{sub 0} method (k{sub 0} INAA method) and high-resolution gamma ray spectrometry. The data reveal the segregation of some elements from associated (trapped and host) rocks to the mineral beryl forming the gemstones. A reference rock standard of the US Geological Survey (USGS BCR-1) was also analysed as a control of the method.

  11. Final workshop proceedings of the collaborative project ''Crystalline ROCK retention processes''

    Energy Technology Data Exchange (ETDEWEB)

    Rabung, Thomas; Garcia, David; Montoya Vanessa; Molinero, Jorge (eds.)

    2014-07-01

    The present document is the proceedings of the Final Workshop of the EURATOM FP7 Collaborative Project CROCK (Crystalline Rock Retention Processes). The key driver for initiation the CP CROCK, identified by national Waste Management Organizations, is the undesired high uncertainty and the associated conservatism with respect to the radionuclide transport in the crystalline host-rock far-field around geological disposal of high-level radioactive wastes.

  12. Implication of haematophagous arthropod salivary proteins in host-vector interactions.

    Science.gov (United States)

    Fontaine, Albin; Diouf, Ibrahima; Bakkali, Nawal; Missé, Dorothée; Pagès, Frédéric; Fusai, Thierry; Rogier, Christophe; Almeras, Lionel

    2011-09-28

    The saliva of haematophagous arthropods contains an array of anti-haemostatic, anti-inflammatory and immunomodulatory molecules that contribute to the success of the blood meal. The saliva of haematophagous arthropods is also involved in the transmission and the establishment of pathogens in the host and in allergic responses. This survey provides a comprehensive overview of the pharmacological activity and immunogenic properties of the main salivary proteins characterised in various haematophagous arthropod species. The potential biological and epidemiological applications of these immunogenic salivary molecules will be discussed with an emphasis on their use as biomarkers of exposure to haematophagous arthropod bites or vaccine candidates that are liable to improve host protection against vector-borne diseases.

  13. Improved RMR Rock Mass Classification Using Artificial Intelligence Algorithms

    Science.gov (United States)

    Gholami, Raoof; Rasouli, Vamegh; Alimoradi, Andisheh

    2013-09-01

    Rock mass classification systems such as rock mass rating (RMR) are very reliable means to provide information about the quality of rocks surrounding a structure as well as to propose suitable support systems for unstable regions. Many correlations have been proposed to relate measured quantities such as wave velocity to rock mass classification systems to limit the associated time and cost of conducting the sampling and mechanical tests conventionally used to calculate RMR values. However, these empirical correlations have been found to be unreliable, as they usually overestimate or underestimate the RMR value. The aim of this paper is to compare the results of RMR classification obtained from the use of empirical correlations versus machine-learning methodologies based on artificial intelligence algorithms. The proposed methods were verified based on two case studies located in northern Iran. Relevance vector regression (RVR) and support vector regression (SVR), as two robust machine-learning methodologies, were used to predict the RMR for tunnel host rocks. RMR values already obtained by sampling and site investigation at one tunnel were taken into account as the output of the artificial networks during training and testing phases. The results reveal that use of empirical correlations overestimates the predicted RMR values. RVR and SVR, however, showed more reliable results, and are therefore suggested for use in RMR classification for design purposes of rock structures.

  14. Host-rock controlled epigenetic, hydrothermal metasomatic origin of the Bayan Obo REEFe-Nb ore deposit, Inner Mongolia, P.R.C.

    Science.gov (United States)

    Chao, E.C.T.; Back, J.M.; Minkin, J.A.; Yinchen, R.

    1992-01-01

    Bayan Obo, a complex rare earth element (REE)FeNb ore deposit, located in Inner Mongolia, P.R.C. is the world's largest known REE deposit. The deposit is chiefly in a marble unit (H8), but extends into an overlying unit of black shale, slate and schist unit (H9), both of which are in the upper part of the Middle Proterozoic Bayan Obo Group. Based on sedimentary structures, the presence of detrital quartz and algal fossil remains, and the 16-km long geographic extent, the H8 marble is a sedimentary deposit, and not a carbonatite of magmatic origin, as proposed by some previous investigators. The unit was weakly regionally metamorphosed (most probably the lower part of the green schist facies) into marble and quartzite prior to mineralization. Tectonically, the deposit is located on the northern flank of the Sino-Korean craton. Many hypotheses have been proposed for the origin of the Bayan Obo deposit; the studies reported here support an epigenetic, hydrothermal, metasomatic origin. Such an origin is supported by field and laboratory textural evidence; 232Th/208Pb internal isochron mineral ages of selected monazite and bastnaesite samples; 40Ar/39Ar incremental heating minimum mineral ages of selected alkali amphiboles; chemical compositions of different generations of both REE ore minerals and alkali amphiboles; and evidence of host-rock influence on the various types of Bayan Obo ores. The internal isochron ages of the REE minerals indicate Caledonian ages for various episodes of REE and Fe mineralization. No evidence was found to indicate a genetic relation between the extensive biotite granitic rocks of Hercynian age in the mine region and the Bayan Obo are deposit, as suggested by previous workers. ?? 1992.

  15. Review of results from SKB R and D on grouting technology for sealing the rock, years 1996-2000

    International Nuclear Information System (INIS)

    Boden, A.; Eklund, D.; Eriksson, Magnus; Lagerblad, B.; Lindblom, U.

    2001-05-01

    In order identify the current state of the art and developments needs, SKB assembled a group of experts from universities and other research organisations. Internal plans were written for the subprojects 'Characterisation of rock for grouting purposes', 'Mechanisms that control the spreading of grout in jointed rock' and 'Cement based grouting material'. Later internal plans for the subprojects 'Demands on grouting' and 'Stabilising and sealing effect of pre-grouting' were written. The aims, which were set for the different subprojects, were in short, to summarise the technological advances, establish a method for rock characterisation from a grouting point of view, develop conceptual and numerical models for simulation of the grouting course, characterise grout in a relevant way, develop understanding and theoretical know-how of durability and chemical influence, identify and develop a number of grouting materials for different situations, develop a specification of requirements for grouting and to verify the theories in laboratory. In the subproject 'Demands on grouting' a literature review was carried out. One important conclusion from the study is that the concept is not very well dealt with in the literature. SKB are currently investigating the prerequisites for the construction of the deep repository. One part of that work is to further specify demands on maximum allowed volume of leakage water for the repository as a whole and also for each part of the deep repository. In the subproject 'Characterisation of rock for grouting purposes', the possibilities of using hydraulic tests for predictions and design have been studied. The idea of this study was to investigate correspondences and deviations to increase the understanding of what is measured in a water-loss measurement. One can draw the conclusion that hydraulic tests are useful when describing the fracture geometry. Numerical modelling and experiments indicate that the specific capacity, Q/Δh, (flow

  16. Linking geology, fluid chemistry, and microbial activity of basalt- and ultramafic-hosted deep-sea hydrothermal vent environments.

    Science.gov (United States)

    Perner, M; Hansen, M; Seifert, R; Strauss, H; Koschinsky, A; Petersen, S

    2013-07-01

    Hydrothermal fluids passing through basaltic rocks along mid-ocean ridges are known to be enriched in sulfide, while those circulating through ultramafic mantle rocks are typically elevated in hydrogen. Therefore, it has been estimated that the maximum energy in basalt-hosted systems is available through sulfide oxidation and in ultramafic-hosted systems through hydrogen oxidation. Furthermore, thermodynamic models suggest that the greatest biomass potential arises from sulfide oxidation in basalt-hosted and from hydrogen oxidation in ultramafic-hosted systems. We tested these predictions by measuring biological sulfide and hydrogen removal and subsequent autotrophic CO2 fixation in chemically distinct hydrothermal fluids from basalt-hosted and ultramafic-hosted vents. We found a large potential of microbial hydrogen oxidation in naturally hydrogen-rich (ultramafic-hosted) but also in naturally hydrogen-poor (basalt-hosted) hydrothermal fluids. Moreover, hydrogen oxidation-based primary production proved to be highly attractive under our incubation conditions regardless whether hydrothermal fluids from ultramafic-hosted or basalt-hosted sites were used. Site-specific hydrogen and sulfide availability alone did not appear to determine whether hydrogen or sulfide oxidation provides the energy for primary production by the free-living microbes in the tested hydrothermal fluids. This suggests that more complex features (e.g., a combination of oxygen, temperature, biological interactions) may play a role for determining which energy source is preferably used in chemically distinct hydrothermal vent biotopes. © 2013 John Wiley & Sons Ltd.

  17. Characterisation of bulk solids

    Energy Technology Data Exchange (ETDEWEB)

    D. McGlinchey [Glasgow Caledonian University, Glasgow (United Kingdom). Centre for Industrial Bulk Solids Handling

    2005-07-01

    Handling of powders and bulk solids is a critical industrial technology across a broad spectrum of industries, including minerals processing. With contributions from leading authors in their respective fields, this book provides the reader with a sound understanding of the techniques, importance and application of particulate materials characterisation. It covers the fundamental characteristics of individual particles and bulk particulate materials, and includes discussion of a wide range of measurement techniques, and the use of material characteristics in design and industrial practice. Contents: Characterising particle properties; Powder mechanics and rheology; Characterisation for hopper and stockpile design; Fluidization behaviour; Characterisation for pneumatic conveyor design; Explosiblility; 'Designer' particle characteristics; Current industrial practice; and Future trends. 130 ills.

  18. Pervasive remagnetization of detrital zircon host rocks in the Jack Hills, Western Australia and implications for records of the early geodynamo

    Science.gov (United States)

    Weiss, Benjamin P.; Maloof, Adam C.; Tailby, Nicholas; Ramezani, Jahandar; Fu, Roger R.; Hanus, Veronica; Trail, Dustin; Bruce Watson, E.; Harrison, T. Mark; Bowring, Samuel A.; Kirschvink, Joseph L.; Swanson-Hysell, Nicholas L.; Coe, Robert S.

    2015-11-01

    It currently is unknown when Earth's dynamo magnetic field originated. Paleomagnetic studies indicate that a field with an intensity similar to that of the present day existed 3.5 billion years ago (Ga). Detrital zircon crystals found in the Jack Hills of Western Australia are some of the very few samples known to substantially predate this time. With crystallization ages ranging from 3.0-4.38 Ga, these zircons might preserve a record of the missing first billion years of Earth's magnetic field history. However, a key unknown is the age and origin of magnetization in the Jack Hills zircons. The identification of >3.9 Ga (i.e., Hadean) field records requires first establishing that the zircons have avoided remagnetization since being deposited in quartz-rich conglomerates at 2.65-3.05 Ga. To address this issue, we have conducted paleomagnetic conglomerate, baked contact, and fold tests in combination with U-Pb geochronology to establish the timing of the metamorphic and alteration events and the peak temperatures experienced by the zircon host rocks. These tests include the first conglomerate test directly on the Hadean-zircon bearing conglomerate at Erawandoo Hill. Although we observed little evidence for remagnetization by recent lightning strikes, we found that the Hadean zircon-bearing rocks and surrounding region have been pervasively remagnetized, with the final major overprinting likely due to thermal and/or aqueous effects from the emplacement of the Warakurna large igneous province at ∼1070 million years ago (Ma). Although localized regions of the Jack Hills might have escaped complete remagnetization, there currently is no robust evidence for pre-depositional (>3.0 Ga) magnetization in the Jack Hills detrital zircons.

  19. Physical properties and petrologic description of rock samples from an IOCG mineralized area in the northern Fennoscandian Shield, Sweden

    DEFF Research Database (Denmark)

    Sandrin, Alessandro; Edfelt, Å.; Waight, Tod Earle

    2009-01-01

    The Tjårrojåkka Fe-Cu prospect in northern Sweden is considered an example of a Fe-oxide Cu-Au (IOCG) deposit and is hosted in metamorphosed Paleoproterozoic volcanic and intrusive rocks. Rock samples from 24 outcrops were collected for petrophysical analysis (magnetic susceptibility, remanent ma...

  20. Seduction and the self: movements through precarity, race and sexuality in Japanese host clubs.

    Science.gov (United States)

    Mahdavi, Pardis

    2018-01-01

    In this article, I build on the notion of precarity to argue that Japanese host clubs are sites in which a particular kind of intimacy and sense of 'belonging' are produced. The analysis highlights host clubs as necessary spaces among many in the precarious economy and as important venues for the production of subjectivity for the male hosts (both migrant and Japanese) as well as for the migrant women who frequent these establishments. In particular, host clubs provide a lucrative employment opportunity for young men - particularly young men who are migrants from the rural parts of Japan or the Philippines (and often Japanese-Filipino young men) who are trying to make a living in the context of what has been characterised as 'precarious Japan'. I draw on extended ethnographic fieldwork to show how the host clubs, though a part of the precarious economy, provide sites of home and belonging for both hosts and their clients.

  1. Finite element simulations of two rock mechanics tests

    International Nuclear Information System (INIS)

    Dahlke, H.J.; Lott, S.A.

    1986-04-01

    Rock mechanics tests are performed to determine in situ stress conditions and material properties of an underground rock mass. To design stable underground facilities for the permanent storage of high-level nuclear waste, determination of these properties and conditions is a necessary first step. However, before a test and its associated equipment can be designed, the engineer needs to know the range of expected values to be measured by the instruments. Sensitivity studies by means of finite element simulations are employed in this preliminary design phase to evaluate the pertinent parameters and their effects on the proposed measurements. The simulations, of two typical rock mechanics tests, the plate bearing test and the flat-jack test, by means of the finite element analysis, are described. The plate bearing test is used to determine the rock mass deformation modulus. The flat-jack test is used to determine the in situ stress conditions of the host rock. For the plate bearing test, two finite element models are used to simulate the classic problem of a load on an elastic half space and the actual problem of a plate bearing test in an underground tunnel of circular cross section. For the flat-jack simulation, a single finite element model is used to simulate both horizontal and vertical slots. Results will be compared to closed-form solutions available in the literature

  2. Forsmark site characterisation - Borehole KFM22 and KFM23: Derivation of porewater data by diffusion experiments

    Energy Technology Data Exchange (ETDEWEB)

    Waber, H. N. [Rock Water Interaction, University of Bern, Bern (Switzerland); Smellie, J. A. T. [Conterra AB, Partille (Sweden)

    2012-04-15

    Within the Detum Project (Detailed Investigations in Forsmark) a 'Methodology comparison for porewater extraction and characterisation techniques' was initiated. This has centred on two shallow boreholes drilled at Soederviken within the northern part of the Forsmark characterisation site. The comparison includes different methodologies to characterise the chemical and isotopic composition of porewater residing in the connected pore space of the rock matrix. The present report describes the chemical and isotopic information of the porewater obtained by out-diffusion experiments and the diffusive isotope equilibration technique applied to originally water saturated drillcore samples. In addition, petrophysical data and solute transport properties of the rock matrix, all necessary for porewater characterisation, have also been elaborated. Specially conditioned drillcore samples were obtained from depths of less than 100 m from boreholes KFM22 and KFM23. Porewater has been extracted successfully from seven samples by laboratory out-diffusion and diffusive isotope exchange methods. The methodology to extract and analyse the porewater is outlined and the analytical data are tabulated. The data are critically reviewed for potential experimental artefacts and their significance with respect to in situ conditions. The connected pore space in the core material representing borehole KFM22 and KFM23 was measured on different types of originally saturated drillcore samples using gravimetric and isotope mass balance methods. Out-diffusion experiments were performed on kg-sized drillcore samples to derive the in situ concentration of the chemically conservative compounds chloride and bromide. The attainment of equilibrium conditions in the out-diffusion experiments was monitored by the concentration change of chloride and bromide as a function of time. The water isotope composition of porewater was determined by the diffusive isotope equilibration technique and by

  3. The value of iodide as a parameter in the chemical characterisation of groundwaters

    Science.gov (United States)

    Lloyd, J. W.; Howard, K. W. F.; Pacey, N. R.; Tellam, J. H.

    1982-06-01

    Brackish and saline groundwaters can severely constrain the use of fresh groundwaters. Their chemical characterisation is important in understanding the hydraulic conditions controlling their presence in an aquifer. Major ions are frequently of limited value but minor ions can be used. Iodide in groundwater is particularly significant in many environments due to the presence of soluble iodine in aquifer matrix materials. Iodide is found in groundwaters in parts of the English Chalk aquifer in concentrations higher than are present in modern seawater. Its presence is considered as a indication of groundwater residence and is of use in the characterisation of fresh as well as saline waters. Under certain circumstances modern seawater intrusion into aquifers along English estuaries produces groundwaters which are easily identified due to iodide enrichment from estuarine muds. In other environments iodide concentrations are of value in distinguishing between groundwaters in limestones and shaly gypsiferous rocks as shown by a study in Qatar, while in an alluvial aquifer study in Peru iodide has been used to identify groundwaters entering the aquifer from adjacent granodiorites.

  4. Tourmaline orbicules in peraluminous monzogranites of Argentina: A study case of fluid-rock interaction between leucogranite and country-rock metasediments

    Science.gov (United States)

    Lira, Raúl; Poklepovic, María F.

    2017-12-01

    Tourmaline orbicules hosted in peraluminous granites are documented worldwide. Seven occurrences were identified in Argentina. Petrography, mineral chemistry, whole-rock geochemistry mass balance and microthermometric studies were performed in orbicules formed at the cupola of a peraluminous A-type leucogranite (Los Riojanos pluton), as well as complementary investigation was achieved in other orbicules of similar geological setting. Mass balance computations in zoned orbicules consistently confirmed immobility of Si both in core and halo, immobility of K and little loss of Al during halo reactions. Elements gained and lost in the schorl-rich core are Fe, Al, Mg, Ti, Ba, Sr, Y and Zr, and Na, K, Rb and Nb, respectively; in the halo, K, Ba, Sr, Y, Zr and locally CaO, were gained, and Fe, Mg, Na, Al, Rb and Nb were lost. The schorl-rich core is enriched in LREE relative to the leucogranite host. A temperature-salinity plot from fluid inclusion data delineates a magmatic-meteoric mixing trend of diluting salinity with descending temperature. Computed δDH20 values from Los Riojanos orbicule schorl suggest magmatic and magmatic-meteoric mixed origins. In Los Riojanos, mass balance constraints suggest that Fe, Mg, Ba, Sr and metallic traces like Zn and V (±Pb) were most likely derived from country-rock schists and gneisses through fluid-rock exchange reactions. A late magmatic-, volatile-rich- fluid exsolution scenario for the formation of orbicules is envisaged. Schorl crystallization was likely delayed to the latest stages of leucogranite consolidation, not only favored by the high diffusivity of B2O3 preferentially partitioned into the exsolved aqueous-rich fluid, but also likely limited to the low availability of Fe and Mg from the scarce granitic biotite, and to the high F- content of the melt. The spatial confination of orbicules to the contact zone granite-metasediments suggests that orbicules were not formed until exsolved fluids reached the boundary with the

  5. Comparison of the intermediate storage periods and areas required for final storage of high-level radioactive waste and spent fuel in various types of host rock

    International Nuclear Information System (INIS)

    Mueller-Hoeppe, N.; Lerch, C.; Jobmann, M.; Filbert, W.

    2005-01-01

    The present new version of the German concept for radioactive waste and spent fuel management is based on the assumption that a repository for high-level waste and spent fuel will not be required until 2030. One reason frequently given for this date is the intermediate storage period of at least forty years to allow the very high initial heat generation to decay. However, calculations performed by the authors have shown that the minimum intermediate storage period for a repository in rock salt is only between four and nineteen years, depending on the final storage concept and the load of the waste package. In clay as a host rock, the minimum intermediate storage times were calculated to be between 31 and 142 years; the same time spans are expected to apply to final storage in magmatic rock, such as granite. The maximum permissible loads of a container holding spent fuel in salt are many times those in clay and granite, respectively. It was also seen that the area requirement for final storage of the same waste structures is roughly a factor of ten higher in clay than in salt. The differences between granite and salt are similar. The reasons for these grave differences, on the one hand, are the better thermal conductivity of salt and, on the other hand, the better heat tolerance of the crushed salt used as backfill material compared to that of bentonite used in the clay and granite concepts. While salt will allow temperatures of up to 200 C, the maximum temperature in bentonite is limited to 100 C. (orig.)

  6. Aespoe Hard Rock Laboratory. Status Report January - April 2009

    Energy Technology Data Exchange (ETDEWEB)

    2009-09-15

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2009/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period January to April 2009.

  7. Aespoe Hard Rock Laboratory. Status Report October - December 2008

    Energy Technology Data Exchange (ETDEWEB)

    2009-03-15

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2008/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the fourth quarter of 2008.

  8. Aespoe Hard Rock Laboratory. Status Report. September - December 2009

    Energy Technology Data Exchange (ETDEWEB)

    2010-05-15

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2009/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period September to December 2009

  9. Aespoe Hard Rock Laboratory. Status Report. January - April 2010

    Energy Technology Data Exchange (ETDEWEB)

    2010-10-15

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2009/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period January to April 2010

  10. Aespoe Hard Rock Laboratory. Status Report May - August 2009

    Energy Technology Data Exchange (ETDEWEB)

    2009-11-15

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2009/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period May to August 2009.

  11. Aespoe Hard Rock Laboratory. Status Report May - August 2010

    Energy Technology Data Exchange (ETDEWEB)

    2011-02-15

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RD and D-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2010/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period May to August 2010.

  12. Aespoe Hard Rock Laboratory. Status Report. April - June 2007

    Energy Technology Data Exchange (ETDEWEB)

    2007-07-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2005- 2010 are presented in SKB's RDandD-Programme 2004 /SKB 2004/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2007/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the second quarter 2007

  13. Aespoe Hard Rock Laboratory. Status Report May - August 2010

    International Nuclear Information System (INIS)

    2011-02-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RD and D-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2010/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period May to August 2010

  14. Aespoe Hard Rock Laboratory. Status Report. July - September 2008

    Energy Technology Data Exchange (ETDEWEB)

    2008-07-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2008/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the third quarter of 2008.

  15. Geochemical modelling of grout-groundwater-rock interactions at the seal-rock interface

    International Nuclear Information System (INIS)

    Alcorn, S.; Christian-Frear, T.

    1992-02-01

    Theoretical investigations into the longevity of repository seals have dealt primarily with the development of a methodology to evaluate interactions between portland cement-based grout and groundwater. Evaluation of chemical thermodynamic equilibria among grout, groundwater, and granitic host rock phases using the geochemical codes EQ3NR/EQ6 suggests that a fracture filled with grout and saturated with groundwater will tend to fill and 'tighten' with time. These calculations predict that some grout and rock phases will dissolve, and that there will be precipitation of secondary phases which collectively have a larger overall volume than that of the material dissolved. Model assumptions include sealing of the fracture in a sluggish hydrologic regime (low gradient) characterized by a saline groundwater environment. The results of the calculations suggest that buffering of the fracture seals chemical system by the granitic rock may be important in determining the long-term fate of grout seals and the resulting phase assemblage in the fracture. The similarity of the predicted reaction product phases to those observed in naturally filled fractures suggests that with time equilibrium will be approached and grouted fractures subject to low hydrologic gradients will continue to seal. If grout injected into fractures materially reduces groundwater flux, the approach to chemical equilibrium will likely be accelerated. In light of this, even very thin or imperfectly grouted fractures would tighten in suitable hydrogeologic environments. In order to determine the period of time necessary to approach equilibrium, data on reaction rates are required. (au)

  16. Sorption data bases for argillaceous rocks and bentonite for the provisional safety analyses for SGT-E2

    International Nuclear Information System (INIS)

    Baeyens, B.; Thoenen, T.; Bradbury, M. H.; Marques Fernandes, M.

    2014-11-01

    In Stage 1 of the Sectoral Plan for Deep Geological Repositories, four rock types have been identified as being suitable host rocks for a radioactive waste repository, namely, Opalinus Clay for a high-level (HLW) and a low- and intermediate-level (L/ILW) repository, and 'Brauner Dogger', Effingen Member and Helvetic Marls for a L/ILW repository. Sorption data bases (SDBs) for all of these host rocks are required for the provisional safety analyses, including all of the bounding porewater and mineralogical composition combinations. In addition, SDBs are needed for the rock formations lying below Opalinus Clay (lower confining units) and for the bentonite backfill in the HLW repository. In some previous work Bradbury et al. (2010) have described a methodology for developing sorption data bases for argillaceous rocks and compacted bentonite. The main factors influencing the sorption in such systems are the phyllosilicate mineral content, particular the 2:1 clay mineral content (illite/smectite/illite-smectite mixed layers) and the water chemistry which determines the radionuclide species in the aqueous phase. The source sorption data were taken predominantly from measurements on illite (or montmorillonite in the case of bentonite) and converted to the defined conditions in each system considered using a series of so called conversion factors to take into account differences in mineralogy, in pH and in radionuclide speciation. Finally, a Lab → Field conversion factor was applied to adapt sorption data measured in dispersed systems (batch experiments) to intact rock under in-situ conditions. This methodology to develop sorption data bases has been applied to the selected host rocks, lower confining units and compacted bentonite taking into account the mineralogical and porewater composition ranges defined. Confidence in the validity and correctness of this methodology has been built up through additional studies: (i) sorption values obtained in the manner

  17. Sorption data bases for argillaceous rocks and bentonite for the provisional safety analyses for SGT-E2

    Energy Technology Data Exchange (ETDEWEB)

    Baeyens, B.; Thoenen, T.; Bradbury, M. H.; Marques Fernandes, M.

    2014-11-15

    In Stage 1 of the Sectoral Plan for Deep Geological Repositories, four rock types have been identified as being suitable host rocks for a radioactive waste repository, namely, Opalinus Clay for a high-level (HLW) and a low- and intermediate-level (L/ILW) repository, and 'Brauner Dogger', Effingen Member and Helvetic Marls for a L/ILW repository. Sorption data bases (SDBs) for all of these host rocks are required for the provisional safety analyses, including all of the bounding porewater and mineralogical composition combinations. In addition, SDBs are needed for the rock formations lying below Opalinus Clay (lower confining units) and for the bentonite backfill in the HLW repository. In some previous work Bradbury et al. (2010) have described a methodology for developing sorption data bases for argillaceous rocks and compacted bentonite. The main factors influencing the sorption in such systems are the phyllosilicate mineral content, particular the 2:1 clay mineral content (illite/smectite/illite-smectite mixed layers) and the water chemistry which determines the radionuclide species in the aqueous phase. The source sorption data were taken predominantly from measurements on illite (or montmorillonite in the case of bentonite) and converted to the defined conditions in each system considered using a series of so called conversion factors to take into account differences in mineralogy, in pH and in radionuclide speciation. Finally, a Lab → Field conversion factor was applied to adapt sorption data measured in dispersed systems (batch experiments) to intact rock under in-situ conditions. This methodology to develop sorption data bases has been applied to the selected host rocks, lower confining units and compacted bentonite taking into account the mineralogical and porewater composition ranges defined. Confidence in the validity and correctness of this methodology has been built up through additional studies: (i) sorption values obtained in the manner

  18. Water - rock interaction in different rock environments

    International Nuclear Information System (INIS)

    Lamminen, S.

    1995-01-01

    The study assesses the groundwater geochemistry and geological environment of 44 study sites for radioactive waste disposal. Initially, the study sites were divided by rock type into 5 groups: (1) acid - intermediate rocks, (2) mafic - ultramafic rocks, (3) gabbros, amphibolites and gneisses that contain calc-silicate (skarn) rocks, (4) carbonates and (5) sandstones. Separate assessments are made of acid - intermediate plutonic rocks and of a subgroup that comprises migmatites, granite and mica gneiss. These all belong to the group of acid - intermediate rocks. Within the mafic -ultramafic rock group, a subgroup that comprises mafic - ultramafic plutonic rocks, serpentinites, mafic - ultramafic volcanic rocks and volcanic - sedimentary schists is also evaluated separately. Bedrock groundwaters are classified by their concentration of total dissolved solids as fresh, brackish, saline, strongly saline and brine-class groundwaters. (75 refs., 24 figs., 3 tabs.)

  19. Characterising rock fracture aperture-spacing relationships using power-law relationships: some considerations

    Science.gov (United States)

    Brook, Martin; Hebblewhite, Bruce; Mitra, Rudrajit

    2016-04-01

    The size-scaling of rock fractures is a well-studied problem in geology, especially for permeability quantification. The intensity of fractures may control the economic exploitation of fractured reservoirs because fracture intensity describes the abundance of fractures potentially available for fluid flow. Moreover, in geotechnical engineering, fractures are important for parameterisation of stress models and excavation design. As fracture data is often collected from widely-spaced boreholes where core recovery is often incomplete, accurate interpretation and representation of fracture aperture-frequency relationships from sparse datasets is important. Fracture intensity is the number of fractures encountered per unit length along a sample scanline oriented perpendicular to the fractures in a set. Cumulative frequency of fractures (F) is commonly related to fracture aperture (A) in the form of a power-law (F = aA-b), with variations in the size of the a coefficient between sites interpreted to equate to fracture frequency for a given aperture (A). However, a common flaw in this approach is that even a small change in b can have a large effect on the response of the fracture frequency (F) parameter. We compare fracture data from the Late Permian Rangal Coal Measures from Australia's Bowen Basin, with fracture data from Jurassic carbonates from the Sierra Madre Oriental, northeastern Mexico. Both power-law coefficient a and exponent b control the fracture aperture-frequency relationship in conjunction with each other; that is, power-laws with relatively low a coefficients have relatively high b exponents and vice versa. Hence, any comparison of different power-laws must take both a and b into consideration. The corollary is that different sedimentary beds in the Sierra Madre carbonates do not show ˜8× the fracture frequency for a given fracture aperture, as based solely on the comparison of coefficient a. Rather, power-law "sensitivity factors" developed from both

  20. Aespoe Hard Rock Laboratory Annual Report 1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-08-01

    The Aespoe Hard Rock Laboratory has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. The Tracer Retention Understanding Experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models that are intended to be used in the licensing of a deep repository for spent fuel. The TRUE -1 experiment including tests with sorbing radioactive tracers in a single fracture over a distance of about 5 m has been completed. Diffusion and sorption in the rock matrix is the dominant retention mechanism over the time scales of the experiments. The main objective of the TRUE Block Scale Experiment is to increase understanding and our ability to predict tracer transport in a fracture network over spatial scales of 10 to 50 m. In total six boreholes have been drilled into the experimental volume located at the 450 m level. The Long-Term Diffusion Experiment is intended as a complement to the dynamic in-situ experiments and the laboratory experiments performed in the TRUE Programme. Diffusion from a fracture into the rock matrix will be studied in situ. The REX project focuses on the reduction of oxygen in a repository after closure due to reactions with rock minerals and microbial activity. Results show that oxygen is consumed within a few days both for the field and laboratory experiments. A new site for the CHEMLAB experiments was selected and prepared during 1999. All future experiment will be conducted in the J niche at 450 m depth. The Prototype Repository Test is focused on testing and demonstrating repository system function. A full-scale prototype including six deposition holes with canisters with electric heaters surrounded by highly compacted bentonite will be built and instrumented. Characterisation of the rock mass in the area of the Prototype repository is completed and the six deposition holes have been drilled. The Backfill and

  1. Aespoe Hard Rock Laboratory Annual Report 1999

    International Nuclear Information System (INIS)

    2000-08-01

    The Aespoe Hard Rock Laboratory has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. The Tracer Retention Understanding Experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models that are intended to be used in the licensing of a deep repository for spent fuel. The TRUE -1 experiment including tests with sorbing radioactive tracers in a single fracture over a distance of about 5 m has been completed. Diffusion and sorption in the rock matrix is the dominant retention mechanism over the time scales of the experiments. The main objective of the TRUE Block Scale Experiment is to increase understanding and our ability to predict tracer transport in a fracture network over spatial scales of 10 to 50 m. In total six boreholes have been drilled into the experimental volume located at the 450 m level. The Long-Term Diffusion Experiment is intended as a complement to the dynamic in-situ experiments and the laboratory experiments performed in the TRUE Programme. Diffusion from a fracture into the rock matrix will be studied in situ. The REX project focuses on the reduction of oxygen in a repository after closure due to reactions with rock minerals and microbial activity. Results show that oxygen is consumed within a few days both for the field and laboratory experiments. A new site for the CHEMLAB experiments was selected and prepared during 1999. All future experiment will be conducted in the J niche at 450 m depth. The Prototype Repository Test is focused on testing and demonstrating repository system function. A full-scale prototype including six deposition holes with canisters with electric heaters surrounded by highly compacted bentonite will be built and instrumented. Characterisation of the rock mass in the area of the Prototype repository is completed and the six deposition holes have been drilled. The Backfill and

  2. Waste-rock interactions in the immediate repository

    International Nuclear Information System (INIS)

    McCarthy, G.J.

    1977-01-01

    The high level wastes (HLW's) to be placed underground in rock formations will contain significant amounts of radioactive decay heat for the first hundred-or-so years of isolation. Several physical-chemical changes analogous to natural geochemical processes can occur during this ''thermal period.'' The waste canister can act as a heat source and cause changes in the mineralogy and properties of the surrounding rocks. Geochemically, this is ''contact metamorphism.'' In the event that the canister is corroded and breached, chemical reactions can occur between the HLW, the surrounding rock and possibly the remains of the canister. In a dry repository which has not been backfilled (and thus pressurized) these interactions could be slow at best and with rates decreasing rapidly as the HLW cools. However, significant interactions can occur in years, months or even days under hydrothermal conditions. These conditions could be created by the combination of HLW heat, overburden pressure and water mobilized from the rocks or derived from groundwater intrusion. At the end of the thermal period these interaction products would constitute the actual HLW form (or ''source term'') subject to the low temperature leaching and migration processes under investigation in other laboratories. It is quite possible that these interaction product waste forms will have superior properties compared to the original HLW. Experimental programs initiated at Penn State during the last year aim at determining the nature of any chemical or mineralogical changes in, or interactions between, HLW solids and host rocks under various repository ambients. The accompanying figures describe the simulated HLW forms and the experimental approach and techniques. Studies with basalts as the repository rock are supported by Rockwell Hanford Operations and with shales by the Office of Waste Isolation

  3. Study of Different Argillaceous Formations Performed in the Context of the FUNMIG project

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, A. M.; Melon, A.; Sanchez, D. M.; Gaucher, E.; Tournassat, C.; Altmann, S.C.; Vinsot, A.; Maes, N.; Craen, M. de; Leupin, O.; Wersin, P.; Astudillo, J.

    2010-07-01

    Argillaceous Rock Formations of low permeability have been selected in several countries as potential geological host rock for the disposal of high level radioactive wastes (HLRW). The general barrier function of the host rock is to retard and attenuate the migration of radionuclides to the biosphere, and the properties of clay minerals sustain this barrier functions. Nowadays, a number of Underground Research Laboratories (URL) have been constructed for a more in depth investigation of the indurated as well as plastic clay rock formations indifferent countries. The HADES under ground research facility (URF) was constructed at Mol (Belgium), where the Boom Clay formation is being studied as a reference host rock formation. The Opalinus Clay formation has been studied in the Mont Terri Rock Laboratory (Switzerland). The Callovo- Oxfordian clayrock is being characterised in the Meuse/Haute-Marne Site at Bure (France). The Boda Claystone is being analysed at Mecsek in Hungary. The knowledge on biogeochemical processes which affect the transport of radionuclides through the geosphere is a key parameter for the safety case of a HLRW repository, which was the aim of the EC Project FUNMIG: Fundamental Processes of Radionuclide Migration. The main factors controlling the mobility of the radionuclides are the chemistry of the pore water, the chemical reactions involving the radionuclides and the sorption processes on clay minerals. There fore, the pore water chemistry plays an important role in determining radionuclide migration characteristics in clay-rock formations. (Author)

  4. Far Field Sorption Data Bases for Performance Assessment of a High-Level Radioactive Waste Repository in an Undisturbed Opalinus Clay Host Rock

    International Nuclear Information System (INIS)

    Bradburry, M.; Baeyens, B.

    2003-08-01

    An Opalinus Clay formation in the Zuercher Weinland is under consideration by Nagra as a potential location for a high-level and long-Iived intermediate-level radioactive waste repository. Performance assessment studies will be performed for this site and the purpose of this report is to describe the procedures used to develop sorption data bases appropriate for an undisturbed Opalinus Clay host rock which are required for such safety analysis calculations. In tight, low water content argillaceous rock formations such as Opalinus Clay, there is uncertainty concerning the in situ pH/P CO 2 . In order to take this intrinsic uncertainty into account porewater chemistries were calculated for a reference case, pH = 7.24, and for two other pH values, 6.3 and 7.8. Sorption data bases are given for the three cases. The basis for the sorption data bases is 'in-house' sorption measurements for Cs(I), Sr(II), Ni(II), Eu(III), Sn(IV), Se(IV), Th(IV) and I(-I) carried out on Opalinus Clay samples from Mont Terri (Canton Jura) since at the time the experiments were performed no core samples from the Benken borehole (Zuercher Weinland) were available. The Opalinus Clay at Mont Terri and Benken are part of the same geological formation . Despite having directly measured data for the above key radionuclides, some of the required distribution ratios (Rd) used to generate the sorption data bases still came from the open literature. An important part of this report is concerned with describing the procedures whereby these selected literature Rd values were modified so as to apply to the Benken Opalinus Clay mineralogy and groundwater chemistries calculated at the three pH values given above. The resulting Rd values were then further modified using so-called Lab→Field transfer factors to produce sorption values which were appropriate to the in situ bulk rock for the selected range of water chemistry conditions. Finally, it is important to have some appreciation of the uncertainties

  5. Review of potential host rocks for radioactive waste disposal in the southeast United States-Southern Piedmont subregion

    International Nuclear Information System (INIS)

    1980-10-01

    A literature study was conducted on the geology of the Southern Piedmont province in the states of Maryland, Virginia, North Carolina, South Carolina, and Georgia. The purpose was to identify geologic areas potentially suitable for containment of a repository for the long-term isolation of solidified radioactive waste. The crystalline rocks of the Southern Piedmont province range in age from Precambrian to Paleozoic, and are predominantly slates, phyllites, argillites, schists, metavolcanics, gneisses, gabbros, and granites. These rock units were classified as either favorable, potentially favorable, or unfavorable as potential study areas based on an evaluation of the geologic, hydrologic, and geotechnical characteristics. No socio-economic factors were considered. Rocks subjected to multiple periods of deformation and metamorphism, or described as highly fractured, or of limited areal extent were generally ranked as unfavorable. Potentially favorable rocks are primarily the high-grade metamorphic gneisses and granites. Sixteen areas were classified as being favorable for additional study. These areas are primarily large igneous granite plutons as follows: the Petersburg granite in Virginia; the Rolesville-Castallia, Churchland, and Landis plutons in North Carolina; the Liberty Hill, Winnsboro, and Ogden plutons in South Carolina; and the Siloam, Elberton, and six unnamed granite plutons in Georgia

  6. Sulfide mineralization in ultramafic rocks of the Faryab ophiolite complex, southern Kerman

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Rajabzadeh

    2015-10-01

    melting of the upper mantle. Sulfide mineralization in the complex is confined to cumulate rocks in northern part of ophiolite column. The mineralization is olivine-rich clinopyroxene and wehrlite. Petrographic investigation of sulfides in host ultramafics indicated two sulfide generations. In the first generation, primary magmatic sulfides occurred as interstitial disseminations, generally as anhedral grains. In the second generation, sulfides formed as veinlets along host rock fractures. The primary sulfides include pyrrhotite, pentlandite, and secondary digenite and pyrite. The primary sulfide content increases with increasing size and amount of clinopyroxene in host rocks. Associated chromian spinels in host ultramafics display disseminated and massive textures. Discussion Generally, mineralization in ophiolites is controlled by two major steps: a partial melting of upper mantle rocks and b crystal fractionation in a magma chamber (Rajabzadeh and Moosavinasab, 2013. The chemical compositions of the analyzed minerals were then used in estimating the conditions in these two steps. The composition of chromian spinel corresponds to chromite of boninitic melts formed in supra-subduction zone environments. Boninitic melts are produced at high degrees of partial melting of mantle peridotites in the presence of water (Edwards et al., 2002. Silicates of the host rocks are mainly clinopyroxene (diopside and augite of the composition Wo47.50 En45.48 Fs3.4, olivine Fo92 and orthopyroxene (enstatite - bronzite of En85 to En88. The main host ultramafic rocks of sulfides are wehrlite and clinopyroxenite, indicating that the sulfide saturation occurred during magmatic evolution of these rocks. This suggests that sulfide mineralization will occur in the northern part the ophiolite. The sulfide grains are anhedral, amoeboidal in shape, and appeared as disseminated interstitial phases, indicating that they were trapped as liquid phases during increase in sulfur fugacity and decrease in

  7. Self-Healing Characteristics of Damaged Rock Salt under Different Healing Conditions

    Directory of Open Access Journals (Sweden)

    Lin Li

    2013-08-01

    Full Text Available Salt deposits are commonly regarded as ideal hosts for geologic energy reservoirs. Underground cavern construction-induced damage in salt is reduced by self-healing. Thus, studying the influencing factors on such healing processes is important. This research uses ultrasonic technology to monitor the longitudinal wave velocity variations of stress-damaged rock salts during self-recovery experiments under different recovery conditions. The influences of stress-induced initial damage, temperature, humidity, and oil on the self-recovery of damaged rock salts are analyzed. The wave velocity values of the damaged rock salts increase rapidly during the first 200 h of recovery, and the values gradually increase toward stabilization after 600 h. The recovery of damaged rock salts is subjected to higher initial damage stress. Water is important in damage recovery. The increase in temperature improves damage recovery when water is abundant, but hinders recovery when water evaporates. The presence of residual hydraulic oil blocks the inter-granular role of water and restrains the recovery under triaxial compression. The results indicate that rock salt damage recovery is related to the damage degree, pore pressure, temperature, humidity, and presence of oil due to the sealing integrity of the jacket material.

  8. Permeability and seismic velocity anisotropy across a ductile-brittle fault zone in crystalline rock

    Science.gov (United States)

    Wenning, Quinn C.; Madonna, Claudio; de Haller, Antoine; Burg, Jean-Pierre

    2018-05-01

    This study characterizes the elastic and fluid flow properties systematically across a ductile-brittle fault zone in crystalline rock at the Grimsel Test Site underground research laboratory. Anisotropic seismic velocities and permeability measured every 0.1 m in the 0.7 m across the transition zone from the host Grimsel granodiorite to the mylonitic core show that foliation-parallel P- and S-wave velocities systematically increase from the host rock towards the mylonitic core, while permeability is reduced nearest to the mylonitic core. The results suggest that although brittle deformation has persisted in the recent evolution, antecedent ductile fabric continues to control the matrix elastic and fluid flow properties outside the mylonitic core. The juxtaposition of the ductile strain zone next to the brittle zone, which is bounded inside the two mylonitic cores, causes a significant elastic, mechanical, and fluid flow heterogeneity, which has important implications for crustal deformation and fluid flow and for the exploitation and use of geothermal energy and geologic waste storage. The results illustrate how physical characteristics of faults in crystalline rocks change in fault zones during the ductile to brittle transitions.

  9. Radionuclide migration in crystalline rock fractures

    International Nuclear Information System (INIS)

    Hoelttae, P.

    2002-01-01

    Crystalline rock has been considered as a host medium for the repository of high radioactive spent nuclear fuel in Finland. The geosphere will act as an ultimate barrier retarding the migration of radionuclides to the biosphere if they are released through the technical barriers. Radionuclide transport is assumed to take place along watercarrying fractures, and retardation will occur both in the fracture and within the rock matrix. To be able to predict the transport and retardation of radionuclides in rock fractures and rock matrices, it is essential to understand the different phenomena involved. Matrix diffusion has been indicated to be an important mechanism, which will retard the transport of radionuclides in rock fractures. Both dispersion and matrix diffusion are processes, which can have similar influences on solute breakthrough curves in fractured crystalline rock. In this work, the migration of radionuclides in crystalline rock fractures was studied by means of laboratory scale column methods. The purpose of the research was to gain a better understanding of various phenomena - particularly matrix diffusion - affecting the transport and retardation behaviour of radionuclides in fracture flow. Interaction between radionuclides and the rock matrix was measured in order to test the compatibility of experimental retardation parameters and transport models used in assessing the safety of underground repositories for spent nuclear fuel. Rock samples of mica gneiss and of unaltered, moderately altered and strongly altered tonalite represented different rock features and porosities offering the possibility to determine experimental boundary limit values for parameters describing both the transport and retardation of radionuclides and rock matrix properties. The dominant matrix diffusion behaviour was demonstrated in porous ceramic column and gas diffusion experiments. Demonstration of the effects of matrix diffusion in crystalline rock fracture succeeded for the

  10. Geometry, mechanics and transmissivity of rock fractures

    International Nuclear Information System (INIS)

    Lanaro, F.

    2001-04-01

    This thesis work investigates methods and tools for characterising, testing and modelling the behaviour of rock fractures. Using a 3D-laser-scanning technique, the topography of the surfaces and their position with respect to one another are measured. From the fracture topography, fracture roughness, angularity and aperture are quantified; the major features used for characterisation. The standard deviations for the asperity heights, surface slopes and aperture are determined. These statistical parameters usually increase/decrease according to power laws of the sampling size, and sometimes reach a sill beyond which they become constant. Also the number of contact spots with a certain area decreases according to a power-law function of the area. These power-law relations reveal the self affine fractal nature of roughness and aperture. Roughness is 'persistent' while aperture varies between 'persistent' and 'anti-persistent' probably depending on the degree of match of the fracture walls. The fractal models for roughness, aperture and contact area are used to develop a constitutive model, based on contact mechanics, for describing the fracture normal and shear deformability. The experimental testing results of normal deformability are simulated well by the model whereas fracture shear deformability is not as well modelled. The model predicts well fracture dilation but is too stiff compared to rock samples. A mathematical description of the aperture pattern during shearing is also formulated. The mean value and covariance of the aperture in shearing is calculated and verifies reported observations. The aperture map of samples is inserted in a numerical program for flow calculation. The 'integral transform method' is used for solving the Reynolds' equation; it transforms the fracture transmissivity pattern into a frequency-based function. This closely resembles the power laws that describe fractals. This function can be described directly from the fractal properties of

  11. Radionuclide transport in fractured rock: quantifying releases from final disposal of high level waste

    International Nuclear Information System (INIS)

    Silveira, Claudia S. da; Alvim, Antonio C.M.

    2013-01-01

    Crystalline rock has been considered as a potentially suitable matrix for high-level radioactive waste (HLW) repository because it is found in very stable geological formations and may have very low permeability. In this study the adopted physical system consists of the rock matrix containing a discrete horizontal fracture in a water saturated porous rock and a system of vertical fractures as a lineament. The transport in the fractures - horizontal and vertical, is assumed to obey a relation convection-diffusion, while the molecular diffusion is considered dominant mechanism of transport in porous rock. In this model the decay chain is considered. We use a code in Fortran 90, where the partial differential equations that describe the movement of radionuclides were discretized by finite differences methods. We use the fully implicit method for temporal discretization schemes. The simulation was performed with relevant data of nuclides in spent fuel for performance assessment in a hypothetical repository, thus quantifying the radionuclides released into the host rock. (author)

  12. A probabilistic approach to rock mechanical property characterization for nuclear waste repository design

    International Nuclear Information System (INIS)

    Kim, Kunsoo; Gao, Hang

    1996-01-01

    A probabilistic approach is proposed for the characterization of host rock mechanical properties at the Yucca Mountain site. This approach helps define the probability distribution of rock properties by utilizing extreme value statistics and Monte Carlo simulation. We analyze mechanical property data of tuff obtained by the NNWSI Project to assess the utility of the methodology. The analysis indicates that laboratory measured strength and deformation data of Calico Hills and Bullfrog tuffs follow an extremal. probability distribution (the third type asymptotic distribution of the smallest values). Monte Carlo simulation is carried out to estimate rock mass deformation moduli using a one-dimensional tuff model proposed by Zimmermann and Finley. We suggest that the results of these analyses be incorporated into the repository design

  13. The Impact of Host Rock Geochemistry on Bacterial Community Structure in Oligotrophic Cave Environments.

    Directory of Open Access Journals (Sweden)

    Hazel A. Barton

    2007-07-01

    Full Text Available Despite extremely starved conditions, caves contain surprisingly diverse microbial communities. Our research is geared toward understanding what ecosystems drivers are responsible for this high diversity. To asses the effect of rock fabric and mineralogy, we carried out a comparative geomicrobiology study within Carlsbad Cavern, New Mexico, USA. Samples were collected from two different geologic locations within the cave: WF1 in the Massive Member of the Capitan Formation and sF88 in the calcareous siltstones of the Yates Formation. We examined the organic content at each location using liquid chromatography mass spectroscopy and analyzed microbial community structure using molecular phylogenetic analyses. In order to assess whether microbial activity was leading to changes in the bedrock at each location, the samples were also examined by petrology, X-ray diffraction (XRD and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX. Our results suggest that on the chemically complex Yates Formation (sF88, the microbial community was significantly more diverse than on the limestone surfaces of the Capitan (WF1, despite a higher total number of cells on the latter. Further, the broader diversity of bacterial species at sF88 reflected a larger range of potential metabolic capabilities, presumably due to opportunities to use ions within the rock as nutrients and for chemolithotrophic energy production. The use of these ions at sF88 is supported by the formation of a corrosion residue, presumably through microbial scavenging activities. Our results suggest that rock fabric and mineralogy may be an important driver of ecosystem function and should be carefully reviewed when carrying out microbial community analysis in cave environments.

  14. Characterising antimicrobial protein-membrane complexes

    International Nuclear Information System (INIS)

    Xun, Gloria; Dingley, Andrew; Tremouilhac, Pierre

    2009-01-01

    Full text: Antimicrobial proteins (AMPs) are host defence molecules that protect organisms from microbial infection. A number of hypotheses for AMP activity have been proposed which involve protein membrane interactions. However, there is a paucity of information describing AMP-membrane complexes in detail. The aim of this project is to characterise the interactions of amoebapore-A (APA-1) with membrane models using primarily solution-state NMR spectroscopy. APA-1 is an AMP which is regulated by a pH-dependent dimerisation event. Based on the atomic resolution solution structure of monomeric APA-1, it is proposed that this dimerisation is a prerequisite for ring-like hexameric pore formation. Due to the cytotoxicity of APA-1, we have developed a cell-free system to produce this protein. To facilitate our studies, we have adapted the cell-free system to isotope label APA-1. 13 C /15 N -enriched APA-1 sample was achieved and we have begun characterising APA-1 dimerisation and membrane interactions using NMR spectroscopy and other biochemical/biophysical methods. Neutron reflectometry is a surface-sensitive technique and therefore represents an ideal technique to probe how APA-1 interacts with membranes at the molecular level under different physiological conditions. Using Platypus, the pH-induced APA-1-membrane interactions should be detectable as an increase of the amount of protein adsorbed at the membrane surface and changes in the membrane properties. Specifically, detailed information of the structure and dimensions of the protein-membrane complex, the position and amount of the protein in the membrane, and the perturbation of the membrane phospholipids on protein incorporation can be extracted from the neutron reflectometry measurement. Such information will enable critical assessment of current proposed mechanisms of AMP activity in bacterial membranes and complement our NMR studies

  15. Petrogenesis of volcanic rocks that host the world-class Agsbnd Pb Navidad District, North Patagonian Massif: Comparison with the Jurassic Chon Aike Volcanic Province of Patagonia, Argentina

    Science.gov (United States)

    Bouhier, Verónica E.; Franchini, Marta B.; Caffe, Pablo J.; Maydagán, Laura; Rapela, Carlos W.; Paolini, Marcelo

    2017-05-01

    We present the first study of the volcanic rocks of the Cañadón Asfalto Formation that host the Navidad world-class Ag + Pb epithermal district located in the North Patagonian Massif, Patagonia, Argentina. These volcanic and sedimentary rocks were deposited in a lacustrine environment during an extensional tectonic regime associated with the breakup of Gondwana and represent the mafic to intermediate counterparts of the mainly silicic Jurassic Chon Aike Volcanic Province. Lava flows surrounded by autobrecciated carapace were extruded in subaerial conditions, whereas hyaloclastite and peperite facies suggest contemporaneous subaqueous volcanism and sedimentation. LA-ICPMS Usbnd Pb ages of zircon crystals from the volcanic units yielded Middle Jurassic ages of 173.9 ± 1.9 Ma and 170.8 ± 3 Ma. In the Navidad district, volcanic rocks of the Cañadón Asfalto Formation show arc-like signatures including high-K basaltic-andesite to high-K dacite compositions, Rb, Ba and Th enrichment relative to the less mobile HFS elements (Nb, Ta), enrichment in light rare earth elements (LREE), Ysbnd Ti depletion, and high Zr contents. These characteristics could be explained by assimilation of crustal rocks in the Jurassic magmas, which is also supported by the presence of zircon xenocrysts with Permian and Middle-Upper Triassic ages (281.3 Ma, 246.5, 218.1, and 201.3 Ma) and quartz xenocrysts recognized in these volcanic units. Furthermore, Sr and Nd isotope compositions suggest a contribution of crustal components in these Middle Jurassic magmas. High-K basaltic andesite has initial 87Sr/86Sr ratios of 0.70416-0.70658 and ξNd(t) values of -5.3 and -4. High-K dacite and andesite have initial 87Sr/86Sr compositions of 0.70584-0.70601 and ξNd(t) values of -4,1 and -3,2. The range of Pb isotope values (206Pb/204Pb = 18.28-18.37, 207Pb/204Pb = 15.61-15.62, and 208Pb/204Pb = 38.26-38.43) of Navidad volcanic rocks and ore minerals suggest mixing Pb sources with contributions of

  16. In-situ experiments on bentonite-based buffer and sealing materials at the Mont Terri rock laboratory (Switzerland)

    Energy Technology Data Exchange (ETDEWEB)

    Wieczorek, K. [Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) GmbH, Braunschweig (Germany); Gaus, I. [National Cooperative for the Disposal of Radioactive Waste (NAGRA), Wettingen (Switzerland); Mayor, J. C. [Empresa Nacional de Residuos Radiactivos SA (ENRESA), Madrid (Spain); and others

    2017-04-15

    Repository concepts in clay or crystalline rock involve bentonite-based buffer or seal systems to provide containment of the waste and limit advective flow. A thorough understanding of buffer and seal evolution is required to make sure the safety functions are fulfilled in the short and long term. Experiments at the real or near-real scale taking into account the interaction with the host rock help to make sure the safety-relevant processes are identified and understood and to show that laboratory-scale findings can be extrapolated to repository scale. Three large-scale experiments on buffer and seal properties performed in recent years at the Mont Terri rock laboratory are presented in this paper: The 1:2 scale HE-E heater experiment which is currently in operation, and the full-scale engineered barrier experiment and the Borehole Seal experiment which have been completed successfully in 2014 and 2012, respectively. All experiments faced considerable difficulties during installation, operation, evaluation or dismantling that required significant effort to overcome. The in situ experiments show that buffer and seal elements can be constructed meeting the expectations raised through small-scale testing. It was, however, also shown that interaction with the host rock caused additional effects in the buffer or seal that could not always be quantified or even anticipated from the experience of small-scale tests (such as re-saturation by pore-water from the rock, interaction with the excavation damaged zone in terms of preferential flow or mechanical effects). This led to the conclusion that testing of the integral system buffer/rock or seal/rock is needed. (authors)

  17. Application of Rqd-Number and Rqd-Volume Multifractal Modelling to Delineate Rock Mass Characterisation in Kahang Cu-Mo Porphyry Deposit, Central Iran / Zastosowanie Metod Modelowania Numerycznego Oraz Modelowania Fraktalnego do Analizy JAKOŚCI SKAŁ W Celu OKREŚLENIA Charakterystyki GÓROTWORU W Obszarze ZŁOŻA Cu-Mo W Kahang, ŚRODKOWY Iran

    Science.gov (United States)

    Yasrebi, Amir Bijan; Wetherelt, Andrew; Foster, Patrick J.; Afzal, Peyman; Coggan, John; Ahangaran, Dariush Kaveh

    2013-12-01

    Identification of rock mass properties in terms of Rock Quality Designation (RQD) plays a significant role in mine planning and design. This study aims to separate the rock mass characterisation based on RQD data analysed from 48 boreholes in Kahang Cu-Mo porphyry deposit situated in the central Iran utilising RQD-Volume (RQD-V) and RQD-Number (RQD-N) fractal models. The log-log plots for RQD-V and RQD-N models show four rock mass populations defined by RQD thresholds of 3.55, 25.12 and 89.12% and 10.47, 41.68 and 83.17% respectively which represent very poor, poor, good and excellent rocks based on Deere and Miller rock classification. The RQD-V and RQD-N models indicate that the excellent rocks are situated in the NW and central parts of this deposit however, the good rocks are located in the most parts of the deposit. The results of validation of the fractal models with the RQD block model show that the RQD-N fractal model of excellent rock quality is better than the RQD-V fractal model of the same rock quality. Correlation between results of the fractal and the geological models illustrates that the excellent rocks are associated with porphyric quartz diorite (PQD) units. The results reveal that there is a multifractal nature in rock characterisation with respect to RQD for the Kahang deposit. The proposed fractal model can be intended for the better understanding of the rock quality for purpose of determination of the final pit slope. Identyfikacja właściwości górotworu odgrywa zasadniczą rolę w planowaniu wydobycia i projektowaniu kopalni. Praca niniejsza ma na celu określenie charakterystyki górotworu w oparciu o dane o jakości skał zebrane na podstawie próbek uzyskanych z 48 odwiertów wykonanych w złożu porfiru Cu-Mo w Kahang, zalegającym w środkowym Iranie przy użyciu modeli fraktalnych RQD-V - Rock Quality Determination-Volume [Określenie jakości skał-objętość]) i RQD-N (Rock Quality Determination-Number [Określenie jakości ska

  18. Whole-rock and mineral compositional constraints on the magmatic evolution of the Ni-Cu-(PGE) sulfide ore-bearing Kevitsa intrusion, northern Finland

    Science.gov (United States)

    Luolavirta, Kirsi; Hanski, Eero; Maier, Wolfgang; Santaguida, Frank

    2018-01-01

    The 2.06 Ga mafic-ultramafic Kevitsa intrusion is located in the Central Lapland greenstone belt. The lower ultramafic part of the intrusion hosts a large disseminated Ni-Cu-(PGE) sulfide deposit with Ni tenors ranging widely from architecture, variations in whole-rock and mineral compositions, and the presence of numerous inclusions and xenoliths. The OLPXs are mainly composed of cumulus olivine (Fo77-89) and clinopyroxene (Mg#81-92) with variable amounts of oikocrystic orthopyroxene (Mg#79-84). They comprise the bulk of the ultramafic cumulates and are the dominant host rocks to the sulfide ore. The host rocks to the regular and false ore type are mineralogically and compositionally similar (Fo 80-83, mostly) and show mildly LREE-enriched REE patterns (CeN/YbN 2), characteristic for the bulk of the Kevitsa ultramafic cumulates. The abundance of orthopyroxene and magnetite is lowest in the host rocks to the Ni-PGE ore type, being in line with the mineral compositions of the silicates, which are the most primitive in the intrusion. However, it contrasts with the LREE-enriched nature of the ore type (CeN/YbN 7), indicating significant involvement of crustal material in the magma. The contrasting intrusive stratigraphy in the different parts of the intrusion likely reflects different emplacement histories. It is proposed that the Kevitsa magma chamber was initially filled by stable continuous flow ("single" input) of basaltic magma followed by differentiation in an at least nearly closed system. In the following stage, new magma pulses were repeatedly emplaced into the interior of the intrusion in a dynamic (open) system forming the sulfide ore bodies. To gain the peculiar compositional and mineralogical characteristics of the Ni-PGE ore type, the related magma probably interacted with different country rocks en route to the Kevitsa magma chamber.

  19. Thermal Inertia of Rocks and Rock Populations

    Science.gov (United States)

    Golombek, M. P.; Jakosky, B. M.; Mellon, M. T.

    2001-01-01

    The effective thermal inertia of rock populations on Mars and Earth is derived from a model of effective inertia versus rock diameter. Results allow a parameterization of the effective rock inertia versus rock abundance and bulk and fine component inertia. Additional information is contained in the original extended abstract.

  20. The subcontinental mantle beneath southern New Zealand, characterised by helium isotopes in intraplate basalts and gas-rich springs

    Science.gov (United States)

    Hoke, L.; Poreda, R.; Reay, A.; Weaver, S. D.

    2000-07-01

    New helium isotope data measured in Cenozoic intraplate basalts and their mantle xenoliths are compared with present-day mantle helium emission on a regional scale from thermal and nonthermal gas discharges on the South Island of New Zealand and the offshore Chatham Islands. Cenozoic intraplate basaltic volcanism in southern New Zealand has ocean island basalt affinities but is restricted to continental areas and absent from adjacent Pacific oceanic crust. Its distribution is diffuse and widespread, it is of intermittent timing and characterised by low magma volumes. Most of the 3He/ 4He ratios measured in fluid inclusions in mantle xenocrysts and basalt phenocrysts such as olivine, garnet, and amphibole fall within the narrow range of 8.5 ± 1.5 Ra (Ra is the atmospheric 3He/ 4He ratio) with a maximum value of 11.5 Ra. This range is characteristic of the relatively homogeneous and degassed upper MORB-mantle helium reservoir. No helium isotope ratios typical of the lower less degassed mantle (>12 Ra), such as exemplified by the modern hot-spot region of Hawaii (with up to 32 Ra) were measured. Helium isotope ratios of less than 8 Ra are interpreted in terms of dilution of upper mantle helium with a radiogenic component, due to either age of crystallisation or small-scale mantle heterogeneities caused by mixing of crustal material into the upper mantle. The crude correlation between age of samples and helium isotopes with generally lower R/Ra values in mantle xenoliths compared with host rock phenocrysts and the in general depleted Nd and Sr isotope ratios and the light rare earth element enrichment of the basalts supports derivation of melts as small melt fractions from a depleted upper mantle, with posteruptive ingrowth of radiogenic helium as a function of lithospheric age. In comparison, the regional helium isotope survey of thermal and nonthermal gas discharges of the South Island of New Zealand shows that mantle 3He anomalies in general do not show an obvious

  1. Failure Behavior and Constitutive Model of Weakly Consolidated Soft Rock

    Directory of Open Access Journals (Sweden)

    Wei-ming Wang

    2013-01-01

    Full Text Available Mining areas in western China are mainly located in soft rock strata with poor bearing capacity. In order to make the deformation failure mechanism and strength behavior of weakly consolidated soft mudstone and coal rock hosted in Ili No. 4 mine of Xinjiang area clear, some uniaxial and triaxial compression tests were carried out according to the samples of rocks gathered in the studied area, respectively. Meanwhile, a damage constitutive model which considered the initial damage was established by introducing a damage variable and a correction coefficient. A linearization process method was introduced according to the characteristics of the fitting curve and experimental data. The results showed that samples under different moisture contents and confining pressures presented completely different failure mechanism. The given model could accurately describe the elastic and plastic yield characteristics as well as the strain softening behavior of collected samples at postpeak stage. Moreover, the model could precisely reflect the relationship between the elastic modulus and confining pressure at prepeak stage.

  2. Aespoe Hard Rock Laboratory. Status Report. September - December 2010

    International Nuclear Information System (INIS)

    2011-04-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. In September 2010, the plans for SKB's research and development of technique during the period 2011-2016 were presented in SKB's RDandD-Programme 2010 /SKB 2010a/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report and the information valid for 2010 is given in /SKB 2010b/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period September to December 2010

  3. Mechanical behavior of host rock close to H.L.W. disposal cavities in a deep granitic formation

    International Nuclear Information System (INIS)

    Hoorelbeke, J.M.; Dourthe, M.

    1986-01-01

    The construction of a H.L.W. repository in a deep granitic formation creates mechanical disturbances in the rock on the scale of the massif and in the nearfield. Amongst all the disturbances noted in the nearfield, this study is concerned with examining the evolution of stresses linked with the excavation of the rock and the rise in temperature in the proximity of the waste packages. Several linear elasticity calculations were made using on the one hand finite element models and on the other simple analytical models. These calculations concern two different storage concepts - in room concept and in floor concept- whose differences in mechanical behavior are analyzed. A study of sensitivity with regard to the characteristics of the rock and to the initial geostatic stresses is presented. The comparison of the calculated stresses with three-dimensional failure criteria gives a clear indication of the satisfactory behavior of granite for final storage. However, the need for experimental study and complementary calculation must be emphasized

  4. Heterogeneous arsenic enrichment in meta-sedimentary rocks in central Maine, United States

    Energy Technology Data Exchange (ETDEWEB)

    O' Shea, Beth, E-mail: bethoshea@sandiego.edu [Department of Marine Science and Environmental Studies, University of San Diego, 5998 Alcala Park, San Diego, CA 92110 (United States); Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, NY 10964 (United States); Stransky, Megan; Leitheiser, Sara [Department of Marine Science and Environmental Studies, University of San Diego, 5998 Alcala Park, San Diego, CA 92110 (United States); Brock, Patrick [School of Earth and Environmental Sciences, Queens College, City University of New York, 65-30 Kissena Blvd., Flushing, NY 11367 (United States); Marvinney, Robert G. [Maine Geological Survey, 93 State House Station, Augusta, ME 04333 (United States); Zheng, Yan [School of Earth and Environmental Sciences, Queens College, City University of New York, 65-30 Kissena Blvd., Flushing, NY 11367 (United States); Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, NY 10964 (United States)

    2015-02-01

    Arsenic is enriched up to 28 times the average crustal abundance of 4.8 mg kg{sup −1} for meta-sedimentary rocks of two adjacent formations in central Maine, USA where groundwater in the bedrock aquifer frequently contains elevated As levels. The Waterville Formation contains higher arsenic concentrations (mean As 32.9 mg kg{sup −1}, median 12.1 mg kg{sup −1}, n = 38) than the neighboring Vassalboro Group (mean As 19.1 mg kg{sup −1}, median 6.0 mg kg{sup −1}, n = 38). The Waterville Formation is a pelitic meta-sedimentary unit with abundant pyrite either visible or observed by scanning electron microprobe. Concentrations of As and S are strongly correlated (r = 0.88, p < 0.05) in the low grade phyllite rocks, and arsenic is detected up to 1944 mg kg{sup −1} in pyrite measured by electron microprobe. In contrast, statistically significant (p < 0.05) correlations between concentrations of As and S are absent in the calcareous meta-sediments of the Vassalboro Group, consistent with the absence of arsenic-rich pyrite in the protolith. Metamorphism converts the arsenic-rich pyrite to arsenic-poor pyrrhotite (mean As 1 mg kg{sup −1}, n = 15) during de-sulfidation reactions: the resulting metamorphic rocks contain arsenic but little or no sulfur indicating that the arsenic is now in new mineral hosts. Secondary weathering products such as iron oxides may host As, yet the geochemical methods employed (oxidative and reductive leaching) do not conclusively indicate that arsenic is associated only with these. Instead, silicate minerals such as biotite and garnet are present in metamorphic zones where arsenic is enriched (up to 130.8 mg kg{sup −1} As) where S is 0%. Redistribution of already variable As in the protolith during metamorphism and contemporary water–rock interaction in the aquifers, all combine to contribute to a spatially heterogeneous groundwater arsenic distribution in bedrock aquifers. - Highlights: • Arsenic is enriched up to 138 mg kg

  5. Localized damage in soft rock: experiments with field measurement techniques

    International Nuclear Information System (INIS)

    Nguyen, T.L.

    2011-01-01

    The research presented in this thesis concerns, firstly, an experimental study on the process of fracture in uniaxial compression of rock samples containing narrow, rectilinear notches inclined with respect to the axis of loading. Secondly, we study the evolution of shear strain localisation towards fracturing and failure in specimens of the same materials with a particular geometry, involving two rounded notches. This geometry, inspired by the work of Meuwissen et al. (1998) for tension tests on metals, promotes the localisation of shear strain in simple compression before fracture. Two different materials were studied: a natural rock of volcanic origin (Neapolitan Tuff) and an artificial 'roc' (CPIR09). In the studies presented, three full-field measurement techniques have been employed in combination: (i) the Digital Image Correlation (DIC), for measurement of kinematic fields at a sample's surface; (ii)acoustic Emission measurements (AE) and AE source location, to follow the evolution of damage in samples during loading; (iii) X-ray tomography (pre-and post-mortem studies), to characterise preexisting defects and discontinuities in the specimens and to better understand the fracturing in 3D. (author)

  6. Materials characterisation

    International Nuclear Information System (INIS)

    Azali Muhammad

    2005-01-01

    Various nuclear techniques have been developed and employed by technologies and scientists worldwide to physically and chemically characterise the material particularly those that have applications in industry. These include small angle neutron scattering (SANS), x-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) for the internal structural study of material, whereas, the x-ray fluorescence (XRF) for the chemical analysis, while the Moessbauer spectroscopy for the study on the magnetic properties and structural identity of material. Basic principle and instrumentations of the techniques are discussed in this chapter. Example of their applications in various disciplines particularly in characterisation of industrial materials also described

  7. Modeling of thermal evolution of near field area around single pit mode nuclear waste canister disposal in soft rocks

    International Nuclear Information System (INIS)

    Bajpai, R.K.; Verma, A.K.; Maheshwar, Sachin

    2016-01-01

    Soft rocks like argillites/shales are under consideration worldwide as host rock for geological disposal of vitrified as well as spent fuel nuclear waste. The near field around disposed waste canister at 400-500m depth witnesses a complex heat field evolution due to varying thermal characteristics of rocks, coupling with hydraulic processes and varying intensity of heat flux from the canister. Smooth heat dissipation across the rock is desirable to avoid buildup of temperature beyond design limit (100 °C) and resultant micro fracturing due to thermal stresses in the rocks and intervening buffer clay layers. This also causes enhancement of hydraulic conductivity of the rocks, radionuclide transport and greater groundwater ingress towards the canister. Hence heat evolution modeling constitutes an important part of safety assessment of geological disposal facilities

  8. Surface diffusivity of cleaved NaCl crystals as a function of humidity: Impedance spectroscopy measurements and implications for crack healing in rock salt

    NARCIS (Netherlands)

    Koelemeijer, P.J.; Peach, C.J.; Spiers, C.J.

    2012-01-01

    Rock salt offers an attractive host rock for geological storage applications, because of its naturally low permeability and the ability of excavation-induced cracks to heal by fluid-assisted diffusive mass transfer. However, while diffusive transport rates in bulk NaCl solution are rapid and well

  9. Mont Terri rock laboratory, 20 years of research: introduction, site characteristics and overview of experiments

    International Nuclear Information System (INIS)

    Bossart, P.; Bernier, F.; Birkholzer, J.

    2017-01-01

    Geologic repositories for radioactive waste are designed as multi-barrier disposal systems that perform a number of functions including the long-term isolation and containment of waste from the human environment, and the attenuation of radionuclides released to the subsurface. The rock laboratory at Mont Terri (canton Jura, Switzerland) in the Opalinus Clay plays an important role in the development of such repositories. The experimental results gained in the last 20 years are used to study the possible evolution of a repository and investigate processes closely related to the safety functions of a repository hosted in a clay rock. At the same time, these experiments have increased our general knowledge of the complex behaviour of argillaceous formations in response to coupled hydrological, mechanical, thermal, chemical, and biological processes. After presenting the geological setting in and around the Mont Terri rock laboratory and an overview of the mineralogy and key properties of the Opalinus Clay, we give a brief overview of the key experiments that are described in more detail in the following research papers to this Special Issue of the Swiss Journal of Geosciences. These experiments aim to characterise the Opalinus Clay and estimate safety-relevant parameters, test procedures, and technologies for repository construction and waste emplacement. Other aspects covered are: bentonite buffer emplacement, high-pH concrete-clay interaction experiments, anaerobic steel corrosion with hydrogen formation, depletion of hydrogen by microbial activity, and finally, release of radionuclides into the bentonite buffer and the Opalinus Clay barrier. In the case of a spent fuel/high-level waste repository, the time considered in performance assessment for repository evolution is generally 1 million years, starting with a transient phase over the first 10,000 years and followed by an equilibrium phase. Experiments dealing with initial conditions, construction, and waste

  10. Mont Terri rock laboratory, 20 years of research: introduction, site characteristics and overview of experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bossart, P. [Swisstopo, Federal Office of Topography, Wabern (Switzerland); Bernier, F. [Federal Agency for Nuclear Control FANC, Brussels (Belgium); Birkholzer, J. [Lawrence Berkeley National Laboratory, Berkeley (United States); and others

    2017-04-15

    Geologic repositories for radioactive waste are designed as multi-barrier disposal systems that perform a number of functions including the long-term isolation and containment of waste from the human environment, and the attenuation of radionuclides released to the subsurface. The rock laboratory at Mont Terri (canton Jura, Switzerland) in the Opalinus Clay plays an important role in the development of such repositories. The experimental results gained in the last 20 years are used to study the possible evolution of a repository and investigate processes closely related to the safety functions of a repository hosted in a clay rock. At the same time, these experiments have increased our general knowledge of the complex behaviour of argillaceous formations in response to coupled hydrological, mechanical, thermal, chemical, and biological processes. After presenting the geological setting in and around the Mont Terri rock laboratory and an overview of the mineralogy and key properties of the Opalinus Clay, we give a brief overview of the key experiments that are described in more detail in the following research papers to this Special Issue of the Swiss Journal of Geosciences. These experiments aim to characterise the Opalinus Clay and estimate safety-relevant parameters, test procedures, and technologies for repository construction and waste emplacement. Other aspects covered are: bentonite buffer emplacement, high-pH concrete-clay interaction experiments, anaerobic steel corrosion with hydrogen formation, depletion of hydrogen by microbial activity, and finally, release of radionuclides into the bentonite buffer and the Opalinus Clay barrier. In the case of a spent fuel/high-level waste repository, the time considered in performance assessment for repository evolution is generally 1 million years, starting with a transient phase over the first 10,000 years and followed by an equilibrium phase. Experiments dealing with initial conditions, construction, and waste

  11. Site investigation requirements for a deep repository

    International Nuclear Information System (INIS)

    Farmer, I.W.

    1992-03-01

    Techniques currently available for measuring geotechnical parameters needed in the design, construction and assessment of a deep underground repository have been critically examined. These techniques have been considered under four main areas: definition of the rock discontinuity structure, definition of the in-situ stress distribution in the rock mass, estimation of the geomechanical characteristics of the rock mass, and estimation of flow and transport characteristics of the rock mass. The review concludes that generally rocks and rock masses are not well characterised by tests from cores or from boreholes and gives reason to support this view. The only parameters which can be measured accurately are laboratory index properties which are useful only in a comparative assessment of different rock types. Finally the review concludes that the only way to obtain useful data on rock behaviour is through large pilot scale tests with appropriate and controlled boundary conditions conducted preferably in the potential host strata. (author)

  12. Modeling fluid-rock interaction at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Viani, B.E.; Bruton, C.J.

    1992-08-01

    Volcanic rocks at Yucca Mountain, Nevada aie being assessed for their suitability as a potential repository for high-level nuclear waste. Recent progress in modeling fluid-rock interactions, in particular the mineralogical and chemical changes that may accompany waste disposal at Yucca Mountain, will be reviewed in this publication. In Part 1 of this publication, ''Geochemical Modeling of Clinoptilolite-Water Interactions,'' solid-solution and cation-exchange models for the zeolite clinoptilolite are developed and compared to experimental and field observations. At Yucca Mountain, clinoptilolite which is found lining fractures and as a major component of zeolitized tuffs, is expected to play an important role in sequestering radionuclides that may escape from a potential nuclear waste repository. The solid-solution and ion-exchange models were evaluated by comparing predicted stabilities and exchangeable cation distributions of clinoptilolites with: (1) published binary exchange data; (2) compositions of coexisting clinoptilolites and formation waters at Yucca Mountain; (3) experimental sorption isotherms of Cs and Sr on zeolitized tuff, and (4) high temperature experimental data. Good agreement was found between predictions and expertmental data, especially for binary exchange and Cs and Sr sorption on clinoptilolite. Part 2 of this publication, ''Geochemical Simulation of Fluid-Rock Interactions at Yucca Mountain,'' describes preliminary numerical simulations of fluid-rock interactions at Yucca Mountain. The solid-solution model developed in the first part of the paper is used to evaluate the stability and composition of clinciptilolite and other minerals in the host rock under ambient conditions and after waste emplacement

  13. Mechanical and physical properties of hydrothermally altered rocks, Taupo Volcanic Zone, New Zealand

    Science.gov (United States)

    Wyering, L. D.; Villeneuve, M. C.; Wallis, I. C.; Siratovich, P. A.; Kennedy, B. M.; Gravley, D. M.; Cant, J. L.

    2014-11-01

    Mechanical characterization of hydrothermally altered rocks from geothermal reservoirs will lead to an improved understanding of rock mechanics in a geothermal environment. To characterize rock properties of the selected formations, we prepared samples from intact core for non-destructive (porosity, density and ultrasonic wave velocities) and destructive laboratory testing (uniaxial compressive strength). We characterised the hydrothermal alteration assemblage using optical mineralogy and existing petrography reports and showed that lithologies had a spread of secondary mineralisation that occurred across the smectite, argillic and propylitic alteration zones. The results from the three geothermal fields show a wide variety of physical rock properties. The testing results for the non-destructive testing shows that samples that originated from the shallow and low temperature section of the geothermal field had higher porosity (15 - 56%), lower density (1222 - 2114 kg/m3) and slower ultrasonic waves (1925 - 3512 m/s (vp) and 818 - 1980 m/s (vs)), than the samples from a deeper and higher temperature section of the field (1.5 - 20%, 2072 - 2837 kg/m3, 2639 - 4593 m/s (vp) and 1476 - 2752 m/s (vs), respectively). The shallow lithologies had uniaxial compressive strengths of 2 - 75 MPa, and the deep lithologies had strengths of 16 - 211 MPa. Typically samples of the same lithologies that originate from multiple wells across a field have variable rock properties because of the different alteration zones from which each sample originates. However, in addition to the alteration zones, the primary rock properties and burial depth of the samples also have an impact on the physical and mechanical properties of the rock. Where this data spread exists, we have been able to derive trends for this specific dataset and subsequently have gained an improved understanding of how hydrothermal alteration affects physical and mechanical properties.

  14. Evaluation criteria for uranium potential of sedimentary basins based on analysis of host sand body and structurally reworking pattern host sand body has been subject to

    International Nuclear Information System (INIS)

    Chen Zuyi; Guo Qingyin; Liu Hongxu

    2005-01-01

    On the basis of the introduction and the analysis of regional evaluation criteria for sandstone-type uranium deposits summarized by uranium geologists of USA and former Soviet Union, and by introducing new scientific progress in the field of sedimentology of clastic rocks, and basin geodynamics, main evaluation criteria composed of host sand body criterion and the criterion of structurally reworking pattern the host sand body has been subject to, are proposed, and the evaluation model based on analyzing the regional tectonic history and the evolution of prototype basin is set up. Finally, taking the Chaoshui basin as an example, the possibility for hosting epigenetic uranium mineralization in each horizon of the basin cover is discussed, then the main prospecting target horizon is discriminated, and potential ore-formation areas are proposed. (authors)

  15. Mechanical effects associated with surface loading of dry rock due to glaciation

    International Nuclear Information System (INIS)

    Wahi, K.K.; Hunter, R.L.

    1985-01-01

    Many scenarios of interest for a repository in the Pasco Basin begin with glaciation. Loading and unloading of joints and fractures due to the weight of ice sheets could affect the hydrologic properties of the host rock and surrounding units. Scoping calculations performed using two-dimensional numerical models with simplifying assumptions predict stress changes and uplift or subsidence caused by an advancing glacier. The magnitudes of surface uplift and subsidence predicted by the study agree well with previous independent predictions. Peak stress unloading near the repository horizon is a small fraction of the ambient stress. Any resultant aperture increase is likewise small. Based on the results of this study, mechanical loading caused by a glacier is expected to have a minimal effect on rock permeability, assuming that the excess compressive loads do not crush the rock. 13 refs., 3 figs., 1 tab

  16. Rock pushing and sampling under rocks on Mars

    Science.gov (United States)

    Moore, H.J.; Liebes, S.; Crouch, D.S.; Clark, L.V.

    1978-01-01

    Viking Lander 2 acquired samples on Mars from beneath two rocks, where living organisms and organic molecules would be protected from ultraviolet radiation. Selection of rocks to be moved was based on scientific and engineering considerations, including rock size, rock shape, burial depth, and location in a sample field. Rock locations and topography were established using the computerized interactive video-stereophotogrammetric system and plotted on vertical profiles and in plan view. Sampler commands were developed and tested on Earth using a full-size lander and surface mock-up. The use of power by the sampler motor correlates with rock movements, which were by plowing, skidding, and rolling. Provenance of the samples was determined by measurements and interpretation of pictures and positions of the sampler arm. Analytical results demonstrate that the samples were, in fact, from beneath the rocks. Results from the Gas Chromatograph-Mass Spectrometer of the Molecular Analysis experiment and the Gas Exchange instrument of the Biology experiment indicate that more adsorbed(?) water occurs in samples under rocks than in samples exposed to the sun. This is consistent with terrestrial arid environments, where more moisture occurs in near-surface soil un- der rocks than in surrounding soil because the net heat flow is toward the soil beneath the rock and the rock cap inhibits evaporation. Inorganic analyses show that samples of soil from under the rocks have significantly less iron than soil exposed to the sun. The scientific significance of analyses of samples under the rocks is only partly evaluated, but some facts are clear. Detectable quantities of martian organic molecules were not found in the sample from under a rock by the Molecular Analysis experiment. The Biology experiments did not find definitive evidence for Earth-like living organisms in their sample. Significant amounts of adsorbed water may be present in the martian regolith. The response of the soil

  17. Radioactive occurrences in veins and igneous and metamorphic rocks of New Mexico with annotated bibliography

    International Nuclear Information System (INIS)

    McLemore, V.T.

    1982-01-01

    From an extensive literature search and field examination of 96 nonsandstone radioactive occurrences, the author compiled an annotated bibliography of over 600 citations and a list of 327 radioactive occurrences in veins and igneous and metamorphic rocks of New Mexico. The citations are indexed by individual radioactive occurrence, geographic area, county, fluorspar deposits and occurrences, geochemical analyses, and geologic maps. In addition, the geology, mineralization, and uranium and thorium potential of 41 geographic areas in New Mexico containing known radioactive occurrences in veins and igneous and metamorphic rocks or that contain host rocks considered favorable for uranium or thorium mineralization are summarized. A list of aerial-radiometric, magnetic, hydrogeochemical, and stream-sediment survey reports is included

  18. Calculations of the Temperature Evolution of a Repository for Spent Fuel in Crystalline and Sedimentary Rocks

    International Nuclear Information System (INIS)

    Sato, R.; Sasaki, T.; Ando, K.; Smith, P.A.; Schneider, J.W.

    1998-08-01

    Thermal evolution is a factor influencing repository design, and must be considered in safety assessment, since many of the processes that affect the long-term safety are temperature dependent. This report presents calculations of the thermal evolution of a repository for spent nuclear fuel. The calculations are based on a provisional repository near-field design in which spent fuel is encapsulated in composite copper-steel canisters, which are emplaced centrally along the horizontal axes of repository tunnels, with the space around the canisters backfilled with bentonite. The temperature of these near-field components varies with time, due to the radiogenic heat produced by the spent fuel. The rate of heat production per canister depends on the initial composition of the fuel, its reactor history, the period of intermediate storage before final disposal and the loading of the canisters. The rate decreases with time, as shorter-lived radionuclides decay. The base-case calculation considers spent fuel that is assumed to generate 1000 W per canister, 40 years after unloading of the fuel from the reactor. The results of the base case calculation indicate that the temperatures at the bentonite/host rock interface, at the centre of the bentonite and at the bentonite/canister interface rise to 98 o C, 103 o C and 126 o C, respectively, before declining towards the ambient temperature of the host rock which, in the base case, is taken to be the crystalline basement of Northern Switzerland. In addition to the base case, parameter variations are examined that investigate the sensitivity of thermal evolution to alternative heat output, design specifications and to uncertainties in material properties. Key findings include (i), that an increase in heat generation to 1500 W per canister 40 years after unloading results in a significant increase of repository temperatures (e.g. at the bentonite/host rock interface, an increase of 22 o C is observed), (ii), that a decrease in

  19. Characteristics and Host Country Drivers of Chinese FDI in Europe

    DEFF Research Database (Denmark)

    Gammeltoft, Peter; Fasshauer, Kirsten

    2017-01-01

    The present study of direct investment from mainland China into Europe complements and extends prior studies by building on a firm-level database comprising of 548 Chinese subsidiaries in 26 countries in EU and EFTA. The study identifies and characterises three segments of subsidiaries...... are particularly important host country factors for attracting Chinese FDI. There is no strong correlation between aggregate national R&D spending and Chinese knowledge-seeking investments, reflecting that such investments tend to be individual and highly idiosyncratic cases. Rather than a wholesale adoption...

  20. Predicting elastic properties of porous fluid-filled rocks by inverting the BGG equation: Applications to seismic and borehole data

    International Nuclear Information System (INIS)

    Benson, A.K.; Wu, J.

    2000-01-01

    Two of the needed elastic parameters for predicting velocities in porous, fluid-filled rocks, the bulk modulus of the empty, porous rock and the shear modulus of the rock, are very difficult to obtain in situ. A novel modeling approach is developed by inverting the Biot-Geertsma-Gassmann (BGG) and shear-wave equations to generate values for the bulk and shear moduli, respectively, by using available velocity and porosity data obtained from borehole logs and/or cores from water/brine-saturated rocks. These values of bulk and shear moduli, along with reasonable in-situ estimates of rock-matrix and fluid parameters generated from the Batzle-Wang formulation, are then used to predict compressional and shear-wave velocities, compressional-shear wave ratios, and reflection coefficients at the interfaces between host rocks and fluid-saturated rocks, either fully or partially saturated with hydrocarbons or water, as a function of depth and/or porosity

  1. Determination of Transport Properties From Flowing Fluid Temperature Logging In Unsaturated Fractured Rocks: Theory And Semi-Analytical Solution

    International Nuclear Information System (INIS)

    Mukhopadhyay, Sumit; Tsang, Yvonne W.

    2008-01-01

    Flowing fluid temperature logging (FFTL) has been recently proposed as a method to locate flowing fractures. We argue that FFTL, backed up by data from high-precision distributed temperature sensors, can be a useful tool in locating flowing fractures and in estimating the transport properties of unsaturated fractured rocks. We have developed the theoretical background needed to analyze data from FFTL. In this paper, we present a simplified conceptualization of FFTL in unsaturated fractured rock, and develop a semianalytical solution for spatial and temporal variations of pressure and temperature inside a borehole in response to an applied perturbation (pumping of air from the borehole). We compare the semi-analytical solution with predictions from the TOUGH2 numerical simulator. Based on the semi-analytical solution, we propose a method to estimate the permeability of the fracture continuum surrounding the borehole. Using this proposed method, we estimated the effective fracture continuum permeability of the unsaturated rock hosting the Drift Scale Test (DST) at Yucca Mountain, Nevada. Our estimate compares well with previous independent estimates for fracture permeability of the DST host rock. The conceptual model of FFTL presented in this paper is based on the assumptions of single-phase flow, convection-only heat transfer, and negligible change in system state of the rock formation. In a sequel paper (Mukhopadhyay et al., 2008), we extend the conceptual model to evaluate some of these assumptions. We also perform inverse modeling of FFTL data to estimate, in addition to permeability, other transport parameters (such as porosity and thermal conductivity) of unsaturated fractured rocks

  2. Aespoe hard rock laboratory. Annual report 2000

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-06-01

    The Aespoe Hard Rock Laboratory constitutes an important component of SKB's work to design, construct, and implement a deep geological repository for spent nuclear fuel and to develop and test methods for characterisation of selected repository sites. The retention effect of the rock has been studied by tracer tests in the Tracer Retention Understanding Experiments (TRUE) and the TRUE Block Scale (TRUE BS). These tests are supplemented by the new Long Term Diffusion Experiment (LTDE). During year 2000 the field experiments of TRUE BS (50 m scale) were completed and preparations made for the LTDE (migration through a fracture wall and into the rock), including boring of approximately 10 m deep hole with 300 mm diameter. Laboratory investigations have difficulties in simulating natural conditions and need supplementary field studies to support validation exercises. A special borehole probe, CHEMLAB, has therefore been designed for different kinds of validation experiments where data can be obtained representative for the in-situ properties of groundwater at repository depth. During 2000 migration experiments were made with actinides (Am, Np and Pu) in CHEMLAB 2, the simplified supplement to CHEMLAB 1. Colloids of nuclides as well as of bentonite might affect the migration of released radionuclides and a separate project was planned during 2000 to assess the existence, stability and mobility of colloids. The development of numerical modelling tools continues with the general objective to improve the numerical models in terms of flow and transport and to update the site-scale and laboratory scale models for the Aespoe HRL. The Matrix Fluid Chemistry project aims at determining the origin and age of matrix fluids and the experiment has been designed to sample matrix fluids from predetermined, isolated borehole sections by specialised equipment. The Aespoe HRL also has the task to demonstrate and perform full scale tests of the function of different components of

  3. Far Field Sorption Data Bases for Performance Assessment of a High-Level Radioactive Waste Repository in an Undisturbed Opalinus Clay Host Rock

    Energy Technology Data Exchange (ETDEWEB)

    Bradburry, M.; Baeyens, B

    2003-08-01

    An Opalinus Clay formation in the Zuercher Weinland is under consideration by Nagra as a potential location for a high-level and long-Iived intermediate-level radioactive waste repository. Performance assessment studies will be performed for this site and the purpose of this report is to describe the procedures used to develop sorption data bases appropriate for an undisturbed Opalinus Clay host rock which are required for such safety analysis calculations. In tight, low water content argillaceous rock formations such as Opalinus Clay, there is uncertainty concerning the in situ pH/P{sub CO{sub 2}}. In order to take this intrinsic uncertainty into account porewater chemistries were calculated for a reference case, pH = 7.24, and for two other pH values, 6.3 and 7.8. Sorption data bases are given for the three cases. The basis for the sorption data bases is 'in-house' sorption measurements for Cs(I), Sr(II), Ni(II), Eu(III), Sn(IV), Se(IV), Th(IV) and I(-I) carried out on Opalinus Clay samples from Mont Terri (Canton Jura) since at the time the experiments were performed no core samples from the Benken borehole (Zuercher Weinland) were available. The Opalinus Clay at Mont Terri and Benken are part of the same geological formation . Despite having directly measured data for the above key radionuclides, some of the required distribution ratios (Rd) used to generate the sorption data bases still came from the open literature. An important part of this report is concerned with describing the procedures whereby these selected literature Rd values were modified so as to apply to the Benken Opalinus Clay mineralogy and groundwater chemistries calculated at the three pH values given above. The resulting Rd values were then further modified using so-called Lab{yields}Field transfer factors to produce sorption values which were appropriate to the in situ bulk rock for the selected range of water chemistry conditions. Finally, it is important to have some

  4. Mixing induced reactive transport in fractured crystalline rocks

    International Nuclear Information System (INIS)

    Martinez-Landa, Lurdes; Carrera, Jesus; Dentz, Marco; Fernàndez-Garcia, Daniel; Nardí, Albert; Saaltink, Maarten W.

    2012-01-01

    In this paper the solute retention properties of crystalline fractured rocks due to mixing-induced geochemical reactions are studied. While fractured media exhibit paths of fast flow and transport and thus short residence times for conservative solutes, at the same time they promote mixing and dilution due to strong heterogeneity, which leads to sharp concentration contrasts. Enhanced mixing and dilution have a double effect that favors crystalline fractured media as a possible host medium for nuclear waste disposal. Firstly, peak radionuclide concentrations are attenuated and, secondly, mixing-induced precipitation reactions are enhanced significantly, which leads to radionuclide immobilization. An integrated framework is presented for the effective modeling of these flow, transport and reaction phenomena, and the interaction between them. In a simple case study, the enhanced dilution and precipitation potential of fractured crystalline rocks are systematically studied and quantified and contrasted it to retention and attenuation in an equivalent homogeneous formation.

  5. A state-of-the-art anisotropic rock deformation model incorporating the development of mobilised shear strength

    Science.gov (United States)

    Noor, M. J. Md; Jobli, A. F.

    2018-04-01

    Currently rock deformation is estimated using the relationship between the deformation modulus Em and the stress-strain curve. There have been many studies conducted to estimate the value of Em. This Em is basically derived from conducting unconfined compression test, UCS. However, the actual stress condition of the rock in the ground is anisotropic stress condition where the rock mass is subjected to different confining and vertical pressures. In addition, there is still no empirical or semi-empirical framework that has been developed for the prediction of rock stress-strain response under anisotropic stress condition. Arock triaxial machine GCTS Triaxial RTX-3000 has been deployed to obtain the anisotropic stress-strain relationship for weathered granite grade II from Rawang, Selangor sampled at depth of 20 m and subjected to confining pressure of 2 MPa, 7.5 MPa and 14 MPa. The developed mobilised shear strength envelope within the specimen of 50 mm diameter and 100 mm height during the application of the deviator stress is interpreted from the stress-strain curves. These mobilised shear strength envelopes at various axial strains are the intrinsic property and unique for the rock. Once this property has been established then it is being used to predict the stress-strain relationship at any confining pressure. The predicted stress-strain curves are compared against the curves obtained from the tests. A very close prediction is achieved to substantiate the applicability of this rock deformation model. This is a state-of-the art rock deformation theory which characterise the deformation base on the applied load and the developed mobilised shear strength within the rock body.

  6. Modelling of excavation depth and fractures in rock caused by tool indentation

    International Nuclear Information System (INIS)

    Kou Shaoquan; Tan Xiangchun; Lindqvist, P.A.

    1997-10-01

    The hydraulic regime after excavation in the near-field rock around deposition holes and deposition tunnels in a spent nuclear fuel repository is of concern for prediction of the saturation process of bentonite buffer and tunnel backfill. The hydraulic condition of main interest in this context is a result of the fracture network that is caused by the excavation. Modelling of the excavation disturbed zone in hard rocks caused by mechanical excavation has been carried out in the Division of Mining Engineering since 1993. This report contains an overview of the work conducted. The mechanical excavation is reasonably simplified as an indentation process of the interaction between rigid indenters and rocks. A large number of experiments have been carried out in the laboratory, and the results used for identifying crushed zones and fracture systems in rock under indentation are presented based on these experiments. The indentation causes crushing and damage of the rock and results in a crushed zone and a cracked zone. The indenter penetrates the rock with a certain depth when the force is over a threshold value relevant to the rock and tool. Outside the cracked zone there are basically three systems of cracks: median cracks, radial cracks, and side cracks. Fully developed radial cracks on each side of the indented area can connect with each other and join with median crack. This forms the so-called radial/median crack system. The influence of the mechanical properties of the rock is discussed based on our conceptual model, and the main factors governing the indentation event are summarised. The cracked zone is dealt with by an analytical fracture model. The side crack is simulated by applying the boundary element method coupled with fracture mechanics. Functional relationships are established relating either the indentation depth or the length of radial/median cracks to the various quantities characterising the physical event, namely the shape and the size of the

  7. Modelling of excavation depth and fractures in rock caused by tool indentation

    Energy Technology Data Exchange (ETDEWEB)

    Kou Shaoquan; Tan Xiangchun; Lindqvist, P.A. [Luleaa Univ. of Technology (Sweden)

    1997-10-01

    The hydraulic regime after excavation in the near-field rock around deposition holes and deposition tunnels in a spent nuclear fuel repository is of concern for prediction of the saturation process of bentonite buffer and tunnel backfill. The hydraulic condition of main interest in this context is a result of the fracture network that is caused by the excavation. Modelling of the excavation disturbed zone in hard rocks caused by mechanical excavation has been carried out in the Division of Mining Engineering since 1993. This report contains an overview of the work conducted. The mechanical excavation is reasonably simplified as an indentation process of the interaction between rigid indenters and rocks. A large number of experiments have been carried out in the laboratory, and the results used for identifying crushed zones and fracture systems in rock under indentation are presented based on these experiments. The indentation causes crushing and damage of the rock and results in a crushed zone and a cracked zone. The indenter penetrates the rock with a certain depth when the force is over a threshold value relevant to the rock and tool. Outside the cracked zone there are basically three systems of cracks: median cracks, radial cracks, and side cracks. Fully developed radial cracks on each side of the indented area can connect with each other and join with median crack. This forms the so-called radial/median crack system. The influence of the mechanical properties of the rock is discussed based on our conceptual model, and the main factors governing the indentation event are summarised. The cracked zone is dealt with by an analytical fracture model. The side crack is simulated by applying the boundary element method coupled with fracture mechanics. Functional relationships are established relating either the indentation depth or the length of radial/median cracks to the various quantities characterising the physical event, namely the shape and the size of the

  8. Workshop on rock mechanics issues in repository design and performance assessment

    International Nuclear Information System (INIS)

    1996-04-01

    The Center for Nuclear Waste Regulatory Analyses organized and hosted a workshop on ''Rock Mechanics Issues in Repository Design and Performance Assessment'' on behalf its sponsor the U.S. Nuclear Regulatory Commission (NRC). This workshop was held on September 19- 20, 1994 at the Holiday Inn Crowne Plaza, Rockville, Maryland. The objectives of the workshop were to stimulate exchange of technical information among parties actively investigating rock mechanics issues relevant to the proposed high-level waste repository at Yucca Mountain and identify/confirm rock mechanics issues important to repository design and performance assessment The workshop contained three technical sessions and two panel discussions. The participants included technical and research staffs representing the NRC and the Department of Energy and their contractors, as well as researchers from the academic, commercial, and international technical communities. These proceedings include most of the technical papers presented in the technical sessions and the transcripts for the two panel discussions

  9. In situ measurement of the thermal conductivity in propylite rock mass

    International Nuclear Information System (INIS)

    Shimooka, Kenji; Araki, Kunio; Suda, Shintaro.

    1982-11-01

    The safety evaluation for the geological disposal of the high level waste becomes an urgent problem to establish the backend of nuclear fuel cycle. The stability of the original host rock and the flow of groundwater will be perturbed by the thermal disturbances from the waste. So the heater experiment at a depth of 90 m below the surface was carried out to study the conduction of decay heat. For measuring the thermal conductivity of propylite rock mass, a cylindrical heater and 13 thermocouples were inserted in 6 boreholes. The power output of the heater was kept at 880 W constant during the experimental periods of 61 days. From the observed temperature rise around the heater, the thermal conductivity 2.1 W/m 0 C was calculated by steady-state calculation. The value of the rock mass was found to be slightly bigger compared with 1.5 - 1.6 W/m 0 C of core samples. (author)

  10. Geochemical constraints on sources of metabolic energy for chemolithoautotrophy in ultramafic-hosted deep-sea hydrothermal systems.

    Science.gov (United States)

    McCollom, Thomas M

    2007-12-01

    Numerical models are employed to investigate sources of chemical energy for autotrophic microbial metabolism that develop during mixing of oxidized seawater with strongly reduced fluids discharged from ultramafic-hosted hydrothermal systems on the seafloor. Hydrothermal fluids in these systems are highly enriched in H(2) and CH(4) as a result of alteration of ultramafic rocks (serpentinization) in the subsurface. Based on the availability of chemical energy sources, inferences are made about the likely metabolic diversity, relative abundance, and spatial distribution of microorganisms within ultramafic-hosted systems. Metabolic reactions involving H(2) and CH(4), particularly hydrogen oxidation, methanotrophy, sulfate reduction, and methanogenesis, represent the predominant sources of chemical energy during fluid mixing. Owing to chemical gradients that develop from fluid mixing, aerobic metabolisms are likely to predominate in low-temperature environments (energy per kilogram of hydrothermal fluid, while anaerobic metabolic reactions can supply about 1 kJ, which is sufficient to support a maximum of approximately 120 mg (dry weight) of primary biomass production by aerobic organisms and approximately 20-30 mg biomass by anaerobes. The results indicate that ultramafic-hosted systems are capable of supplying about twice as much chemical energy as analogous deep-sea hydrothermal systems hosted in basaltic rocks.

  11. Effect of Hydrothermal Alteration on Rock Properties in Active Geothermal Setting

    Science.gov (United States)

    Mikisek, P.; Bignall, G.; Sepulveda, F.; Sass, I.

    2012-04-01

    Hydrothermal alteration records the physical-chemical changes of rock and mineral phases caused by the interaction of hot fluids and wall rock, which can impact effective permeability, porosity, thermal parameters, rock strength and other rock properties. In this project, an experimental approach has been used to investigate the effects of hydrothermal alteration on rock properties. A rock property database of contrastingly altered rock types and intensities has been established. The database details horizontal and vertical permeability, porosity, density, thermal conductivity and thermal heat capacity for ~300 drill core samples from wells THM12, THM13, THM14, THM17, THM18, THM22 and TH18 in the Wairakei-Tauhara geothermal system (New Zealand), which has been compared with observed hydrothermal alteration type, rank and intensity obtained from XRD analysis and optical microscopy. Samples were selected from clay-altered tuff and intercalated siltstones of the Huka Falls Formation, which acts as a cap rock at Wairakei-Tauhara, and tuffaceous sandstones of the Waiora Formation, which is a primary reservoir-hosting unit for lateral and vertical fluid flows in the geothermal system. The Huka Falls Formation exhibits argillic-type alteration of varying intensity, while underlying Waiora Formations exhibits argillic- and propylithic-type alteration. We plan to use a tempered triaxial test cell at hydrothermal temperatures (up to 200°C) and pressures typical of geothermal conditions, to simulate hot (thermal) fluid percolation through the rock matrix of an inferred "reservoir". Compressibility data will be obtained under a range of operating (simulation reservoir) conditions, in a series of multiple week to month-long experiments that will monitor change in permeability and rock strength accompanying advancing hydrothermal alteration intensity caused by the hot brine interacting with the rock matrix. We suggest, our work will provide new baseline information concerning

  12. Hard-rock GMPEs versus Vs30-Kappa Host-to-Target Adjustment Techniques : Why so Large Differences in High Frequency Hard-Rock Motion ?

    Science.gov (United States)

    Bard, P. Y.; Laurendeau, A.; Hollender, F.; Perron, V.; Hernandez, B.; Foundotos, L.

    2016-12-01

    Assessment of local seismic hazard on hard rock sites (1000 processing of the Japanese KiK-net recordings from stiff sites (500 deep, within-motion to outcropping motion, or on a deconvolution of surface recordings using the velocity profile and 1D simulation, which has been performed both in the response spectrum and Fourier domains. Each of these virtual "outcropping hard-rock motion" data sets has then been used to derive GMPEs with simple functional forms, using as site condition proxy the S-wave velocity at depth (VSDH), ranging from 1000 to 3000 m/s. Both sets provide very similar predictions, which are much smaller at high frequencies (f > 10 Hz) than those estimated with the traditional HTTA technique - by a factor up to 3-4,. These differences decrease for decreasing frequency, and become negligible at low frequency (f shallow, moderate velocity layers. Not only this resonant amplification is not correctly accounted for by the quarter-wavelength approach used in the traditional HTTA adjustment techniques, but it may also significantly impact and bias the κ measurements, and the (VS30- κ0) relationships implicitly used in HTTA techniques.

  13. Limited by the host: Host age hampers establishment of holoparasite Cuscuta epithymum

    Science.gov (United States)

    Meulebrouck, Klaar; Verheyen, Kris; Brys, Rein; Hermy, Martin

    2009-07-01

    A good understanding of the relationship between plant establishment and the ecosystem of which they are part of is needed to conserve rare plant species. Introduction experiments offer a direct test of recruitment limitation, but generally only the seed germination and seedling phases are monitored. Thus the relative importance of different establishment stages in the process of recruitment is not considered. This is particularly true for parasitic plants where empirical data are generally missing. During two consecutive growing seasons we examined the effect of heathland management applications, degree of heathland succession (pioneer, building and mature phase) and seed-density on the recruitment and establishment of the endangered holoparasite Cuscuta epithymum. In general, recruitment after two growing seasons was low with 4.79% of the sown seeds that successfully emerged to the seedling stage and a final establishment of 89 flowering adults (i.e. <1.5% of the sown seeds). Although a higher seed-density resulted in a higher number of seedlings, seed-density did not significantly affected relative germination percentages. The management type and subsequent heath succession had no significant effect on seedling emergence; whereas, seedling attachment to the host, establishment and growth to full-grown size were hampered in older heath vegetation (i.e. high, dense, and mature canopy). Establishment was most successful in turf-cut pioneer heathland, characterised by a relatively open and low vegetation of young Calluna vulgaris. The age of C. vulgaris, C. epithymum's main host, proved to be the most limiting factor. These results emphasise the importance of site quality (i.e. successional phase of its host) on recruitment success of C. epithymum, which is directly affected by the management applied to the vegetation. Lack of any heathland management will thus seriously restrict establishment of the endangered parasite.

  14. Identification and Quantification of Carbonate Species Using Rock-Eval Pyrolysis

    Directory of Open Access Journals (Sweden)

    Pillot D.

    2013-03-01

    Full Text Available This paper presents a new reliable and rapid method to characterise and quantify carbonates in solid samples based on monitoring the CO2 flux emitted by progressive thermal decomposition of carbonates during a programmed heating. The different peaks of destabilisation allow determining the different types of carbonates present in the analysed sample. The quantification of each peak gives the respective proportions of these different types of carbonates in the sample. In addition to the chosen procedure presented in this paper, using a standard Rock-Eval 6 pyrolyser, calibration characteristic profiles are also presented for the most common carbonates in nature. This method should allow different types of application for different disciplines, either academic or industrial.

  15. Aespoe Hard Rock Laboratory. Status Report. September - December 2010

    Energy Technology Data Exchange (ETDEWEB)

    2011-04-15

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. In September 2010, the plans for SKB's research and development of technique during the period 2011-2016 were presented in SKB's RDandD-Programme 2010 /SKB 2010a/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report and the information valid for 2010 is given in /SKB 2010b/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period September to December 2010

  16. Hydraulic characterisation of karst systems with man-made tracers

    International Nuclear Information System (INIS)

    Werner, A.

    1998-01-01

    Tracer experiments using man-made tracers are common in hydrogeological exploration of groundwater aquifers in karst systems. In the present investigation, a convection-dispersion model (multidispersion model with consideration of several flow paths) and a single-cleft model (consideration of the diffusion between the cleft and the surrounding rock matrix) were used for evaluating tracer experiments in the main hydrological system of the saturated zone of karst systems. In addition to these extended analytical solutions, a numerical transport model was developed for investigating the influence of the transient flow rate on the flow and transport parameters. Comparative evaluations of the model approaches for the evaluation of tracer experiments were made in four different karst systems: Danube-Aach, Paderborn, Slowenia and Lurbach, of which the Danube-Aach system was considered as the most important. The investigation also comprised three supplementary experiments in order to enable a complete hydraulic characterisation of the system. (orig./SR) [de

  17. Evaluation of Used Fuel Disposition in Clay-Bearing Rock

    Energy Technology Data Exchange (ETDEWEB)

    Jove-Colon, Carlos F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Weck, Philippe F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hammond, Glenn Edward [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kuhlman, Kristopher L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Zheng, Liange [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rutqvist, Jonny [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kim, Kunhwi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Houseworth, James [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Caporuscio, Florie Andre [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Cheshire, Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Palaich, Sarah [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Norskog, Katherine E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Zavarin, Mavrik [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wolery, Thomas J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Jerden, James L. [Argonne National Lab. (ANL), Argonne, IL (United States); Copple, Jacqueline M. [Argonne National Lab. (ANL), Argonne, IL (United States); Cruse, Terry [Argonne National Lab. (ANL), Argonne, IL (United States); Ebert, William L. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-09-04

    Deep geological disposal of nuclear waste in clay/shale/argillaceous rock formations has received much consideration given its desirable attributes such as isolation properties (low permeability), geochemically reduced conditions, slow diffusion, sorbtive mineralogy, and geologically widespread (Jové Colón et al., 2014). There is a wealth of gained scientific expertise on the behavior of clay/shale/ argillaceous rock given its focus in international nuclear waste repository programs that includes underground research laboratories (URLs) in Switzerland, France, Belgium, and Japan. Jové Colón et al. (2014) have described some of these investigative efforts in clay rock ranging from site characterization to research on the engineered barrier system (EBS). Evaluations of disposal options that include nuclear waste disposition in clay/shale/argillaceous rock have determined that this host media can accommodate a wide range of waste types. R&D work within the Used Fuel Disposition Campaign (UFDC) assessing thermal effects and fluid-mineral interactions for the disposition of heat-generating waste have so far demonstrated the feasibility for the EBS and clay host rock to withstand high thermal loads. This report represents the continuation of disposal R&D efforts on the advancement and refinement of coupled Thermal-Hydrological-Mechanical-Chemical (THMC), hydrothermal experiments on clay interactions, used fuel degradation (source term), and thermodynamic modeling and database development. The development and implementation of a clay/shale/argillite reference case described in Jové Colón et al. (2014) for FY15 will be documented in another report (Mariner et al. 2015) – only a brief description will be given here. This clay reference case implementation is the result of integration efforts between the GDSA PA and disposal in argillite work packages. The assessment of sacrificial zones in the EBS is being addressed through experimental work along with 1D reactive

  18. Laboratory tools to quantify biogenic dissolution of rocks and minerals: a model rock biofilm growing in percolation columns

    Directory of Open Access Journals (Sweden)

    Franz eSeiffert

    2016-04-01

    Full Text Available Sub-aerial biofilms (SAB are ubiquitous, self-sufficient microbial ecosystems found on mineral surfaces at all altitudes and latitudes. SABs, which are the principal causes of weathering on exposed terrestrial surfaces, are characterised by patchy growth dominated by associations of algae, cyanobacteria, fungi and heterotrophic bacteria. A recently developed in vitro system to study colonisation of rocks exposed to air included two key SAB participants - the rock-inhabiting ascomycete Knufia petricola (CBS 123872 and the phototrophic cyanobacterium Nostoc punctiforme ATCC29133. Both partners are genetically tractable and we used them here to study weathering of granite, K-feldspar and plagioclase. Small fragments of the various rocks or minerals (1 to 6 mm were packed into flow-through columns and incubated with 0.1% glucose and 10 µM thiamine-hydrochloride (90 µL.min-1 to compare weathering with and without biofilms. Dissolution of the minerals was followed by: analysing (i the degradation products in the effluent from the columns via Inductively Coupled Plasma Spectroscopy and (ii by studying polished sections of the incubated mineral fragment/grains using scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray analyses. K. petricola/N. punctiforme stimulated release of Ca, Na, Mg and Mn. Analyses of the polished sections confirmed depletion of Ca, Na and K near the surface of the fragments. The abrupt decrease in Ca concentration observed in peripheral areas of plagioclase fragments favoured a dissolution-reprecipitation mechanism. Percolation columns in combination with a model biofilm can thus be used to study weathering in closed systems. Columns can easily be filled with different minerals and biofilms, the effluent as well as grains can be collected after long-term exposure under axenic conditions and easily analysed.

  19. Laboratory tools to quantify biogenic dissolution of rocks and minerals: a model rock biofilm growing in percolation columns

    Science.gov (United States)

    Seiffert, Franz; Bandow, Nicole; Kalbe, Ute; Milke, Ralf; Gorbushina, Anna

    2016-04-01

    Sub-aerial biofilms (SAB) are ubiquitous, self-sufficient microbial ecosystems found on mineral surfaces at all altitudes and latitudes. SABs, which are the principal causes of weathering on exposed terrestrial surfaces, are characterised by patchy growth dominated by associations of algae, cyanobacteria, fungi and heterotrophic bacteria. A recently developed in vitro system to study colonisation of rocks exposed to air included two key SAB participants - the rock-inhabiting ascomycete Knufia petricola (CBS 123872) and the phototrophic cyanobacterium Nostoc punctiforme ATCC29133. Both partners are genetically tractable and we used them here to study weathering of granite, K-feldspar and plagioclase. Small fragments of the various rocks or minerals (1 to 6 mm) were packed into flow-through columns and incubated with 0.1% glucose and 10 µM thiamine-hydrochloride (90 µL.min-1) to compare weathering with and without biofilms. Dissolution of the minerals was followed by: analysing (i) the degradation products in the effluent from the columns via Inductively Coupled Plasma Spectroscopy and (ii) by studying polished sections of the incubated mineral fragment/grains using scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray analyses. K. petricola/N. punctiforme stimulated release of Ca, Na, Mg and Mn. Analyses of the polished sections confirmed depletion of Ca, Na and K near the surface of the fragments. The abrupt decrease in Ca concentration observed in peripheral areas of plagioclase fragments favoured a dissolution-reprecipitation mechanism. Percolation columns in combination with a model biofilm can thus be used to study weathering in closed systems. Columns can easily be filled with different minerals and biofilms, the effluent as well as grains can be collected after long-term exposure under axenic conditions and easily analysed.

  20. Diffusivity database (DDB) for major rocks. Database for the second progress report

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Haruo

    1999-10-01

    A database for diffusivity for a data setting of effective diffusion coefficients in rock matrices in the second progress report, was developed. In this database, 3 kinds of diffusion coefficients: effective diffusion coefficient (De), apparent diffusion coefficient (Da) and free water diffusion coefficient (Do) were treated. The database, based on literatures published between 1980 and 1998, was developed considering the following points. (1) Since Japanese geological environment is focused in the second progress report, data for diffusion are collected focused on Japanese major rocks. (2) Although 22 elements are considered to be important in performance assessment for geological disposal, all elements and aquatic tracers are treated in this database development considering general purpose. (3) Since limestone, which belongs to sedimentary rock, can become one of the natural resources and is inappropriate as a host rock, it is omitted in this database development. Rock was categorized into 4 kinds of rocks; acid crystalline rock, alkaline crystalline rock, sedimentary rock (argillaceous/tuffaceous rock) and sedimentary rock (psammitic rock/sandy stone) from the viewpoint of geology and mass transport. In addition, rocks around neutrality among crystalline rock were categorized into the alkaline crystalline rock in this database. The database is composed of sub-databases for 4 kinds of rocks. Furthermore, the sub-databases for 4 kinds of the rocks are composed of databases to individual elements, in which totally, 24 items such as species, rock name, diffusion coefficients (De, Da, Do), obtained conditions (method, porewater, pH, Eh, temperature, atmosphere, etc.), etc. are input. As a result of literature survey, for De values for acid crystalline rock, totally, 207 data for 18 elements and one tracer (hydrocarbon) have been reported and all data were for granitic rocks such as granite, granodiorite and biotitic granite. For alkaline crystalline rock, totally, 32

  1. Genomic characterisation of Almpiwar virus, Harrison Dam virus and Walkabout Creek virus; three novel rhabdoviruses from northern Australia

    Directory of Open Access Journals (Sweden)

    Jane McAllister

    2014-09-01

    Full Text Available Rhabdoviridae represent a diverse group of viruses with the potential to cause disease in humans, animals and plants. Currently there are nine genera in the family; however a large number of rhabdoviruses remain unassigned. Here we characterise three novel rhabdoviruses genomes. Almpiwar virus (ALMV, isolated from skinks in northern Queensland, is the first completely sequenced rhabdovirus from squamates, with serological studies indicating multiple animal host species. Harrison Dam virus (HARDV and Walkabout Creek virus (WACV were isolated from mosquitoes in the Northern Territory and biting midges in southern Queensland respectively and their vertebrate hosts remain unknown. Serological cross-neutralisation tests with other Australian rhabdoviruses indicate that ALMV, WACV and HARDV are distinct viruses with little antigenic cross-reactivity. Next-generation sequencing revealed that all viruses encode the core proteins common to rhabdoviruses (N, P, M, G and L, plus additional ORFs between the M and G genes. HARDV also contains a small ORF between the G and L genes. Phylogenetic analysis of N and L proteins suggests that HARDV and WACV share a common lineage with the tupaviruses and Sandjimba group, whereas ALMV is a distinct and divergent virus showing no clear relationship to any rhabdovirus except the recently characterised Niahka virus (NIAV.

  2. Comparison of sorption measurements on argillaceous rocks and bentonite with predictions using the SGT-E2 approach to derive sorption data bases

    Energy Technology Data Exchange (ETDEWEB)

    Bradbury, M. H.; Baeyens, B; Marques Fernandes, M.

    2014-11-15

    In Stage 1 of the Sectoral Plan for Deep Geological Repositories, four rock types have been identified as being suitable host rocks for a radioactive waste repository, namely, Opalinus Clay for a high-level (HLW) and a low- and intermediate-level (L/ILW) repository, and 'Brauner Dogger', Effingen Member and Helvetic Marls for a L/ILW repository. Sorption data bases (SDBs) for all of these host rocks are required for the provisional safety analyses, including all of the bounding porewater and mineralogical composition combinations. In addition, SDBs are needed for the rock formations lying below Opalinus Clay (lower confining units) and for the bentonite backfill in the HLW repository. A detailed procedure was developed for deriving SDBs for argillaceous rocks (and bentonite) based on sorption edge measurements on illite (and montmorillonite), the hypothesis that 2:1 clay minerals are the dominant sorbents and a series of so called conversion factors which take into account the different radionuclide speciations in the different porewaters. Since this methodology for generating SDBs is relatively new, a validation and demonstration of the robustness and reliability of the sorption values derived was required. This report describes an extensive piece of work in which blind predictions of sorption values were compared with measured ones. Sorption isotherms were measured for the following metal ions Cs(I), Co(II), Ni(II), Eu(III), Th(IV) and U(VI) in a range of realistic porewater chemistries for a range of host rock mineralogies. In the end 53 isotherm data sets were measured. For each of these isotherms a prediction was made of the sorption at trace concentrations using the SDB derivation methodology. A comparison between measured and predicted values for each case was then made. This validation study shows that the methodology used for the derivation of the sorption data bases for argillaceous rocks and bentonite produces reliable sorption values. (authors)

  3. Strategy for the use of laboratory methods in the site investigations programme for the transport properties of the rock

    International Nuclear Information System (INIS)

    Widestrand, Henrik; Byegaard, Johan; Ohlsson, Yvonne; Tullborg, Eva-Lena

    2003-06-01

    This report comprises a strategy for the handling of laboratory investigations of diffusivity and sorption characteristics within the discipline-specific programme 'Transport Properties of the Rock' in the SKB site investigations. The aim of the transport programme is to investigate the solute transport properties at a site in order to acquire data that are required for an assessment of the long-term performance and radiological safety of the deep repository. The result of the transport programme is the Transport Properties Site Descriptive Model, i.e. a description of the site-specific properties for the transport of solutes in the groundwater at a site. A strategy for the methodology, control of sampling and characterisation programme and interpretation of the results, is proposed. The basis for the laboratory investigations is a conceptual geological model based on the geological model produced in the geology programme. Major and minor types of rock and fractures are defined and characterised according to the quality of the general database and site-specific needs. The selection of samples and analyses is determined in close co-operation with the geology, hydrogeology, hydrogeochemistry and rock mechanics programmes. The result of the laboratory investigations is a retardation model, which is used as an input in the Transport Properties Site Descriptive Model. The interpretation and production of a retardation model is described and exemplified. Lastly, method-specific strategies and recommendations are given, including strategies for the selection of tracers in the experiments and for the treatment of the sampled geologic materials

  4. Strategy for the use of laboratory methods in the site investigations programme for the transport properties of the rock

    Energy Technology Data Exchange (ETDEWEB)

    Widestrand, Henrik; Byegaard, Johan [Geosigma AB, Kungaelv (Sweden); Ohlsson, Yvonne [SWECO VIAK AB, Stockholm (Sweden); Tullborg, Eva-Lena [Terralogica AB, Graabo (Sweden)

    2003-06-01

    This report comprises a strategy for the handling of laboratory investigations of diffusivity and sorption characteristics within the discipline-specific programme 'Transport Properties of the Rock' in the SKB site investigations. The aim of the transport programme is to investigate the solute transport properties at a site in order to acquire data that are required for an assessment of the long-term performance and radiological safety of the deep repository. The result of the transport programme is the Transport Properties Site Descriptive Model, i.e. a description of the site-specific properties for the transport of solutes in the groundwater at a site. A strategy for the methodology, control of sampling and characterisation programme and interpretation of the results, is proposed. The basis for the laboratory investigations is a conceptual geological model based on the geological model produced in the geology programme. Major and minor types of rock and fractures are defined and characterised according to the quality of the general database and site-specific needs. The selection of samples and analyses is determined in close co-operation with the geology, hydrogeology, hydrogeochemistry and rock mechanics programmes. The result of the laboratory investigations is a retardation model, which is used as an input in the Transport Properties Site Descriptive Model. The interpretation and production of a retardation model is described and exemplified. Lastly, method-specific strategies and recommendations are given, including strategies for the selection of tracers in the experiments and for the treatment of the sampled geologic materials.

  5. CCS site characterisation criteria

    Energy Technology Data Exchange (ETDEWEB)

    Bachu, S.; Hawkes, C.; Lawton, D.; Pooladi-Darvish, M.; Perkins, E.

    2009-12-15

    IEA GHG recently commissioned the Alberta Research Counil in Canada to conduct a review of storage site selection criteria and site characterisation methods in order to produce a synthesis report. This report reviews the literature on the subject on the site seleciton and characterisation since the publication of the IPCC Special Report on CCS, and provides a synthesis and classification of criteria. 161 refs.

  6. Estimating the Wet-Rock P-Wave Velocity from the Dry-Rock P-Wave Velocity for Pyroclastic Rocks

    Science.gov (United States)

    Kahraman, Sair; Fener, Mustafa; Kilic, Cumhur Ozcan

    2017-07-01

    Seismic methods are widely used for the geotechnical investigations in volcanic areas or for the determination of the engineering properties of pyroclastic rocks in laboratory. Therefore, developing a relation between the wet- and dry-rock P-wave velocities will be helpful for engineers when evaluating the formation characteristics of pyroclastic rocks. To investigate the predictability of the wet-rock P-wave velocity from the dry-rock P-wave velocity for pyroclastic rocks P-wave velocity measurements were conducted on 27 different pyroclastic rocks. In addition, dry-rock S-wave velocity measurements were conducted. The test results were modeled using Gassmann's and Wood's theories and it was seen that estimates for saturated P-wave velocity from the theories fit well measured data. For samples having values of less and greater than 20%, practical equations were derived for reliably estimating wet-rock P-wave velocity as function of dry-rock P-wave velocity.

  7. An XFEM Model for Hydraulic Fracturing in Partially Saturated Rocks

    Directory of Open Access Journals (Sweden)

    Salimzadeh Saeed

    2016-01-01

    Full Text Available Hydraulic fracturing is a complex multi-physics phenomenon. Numerous analytical and numerical models of hydraulic fracturing processes have been proposed. Analytical solutions commonly are able to model the growth of a single hydraulic fracture into an initially intact, homogeneous rock mass. Numerical models are able to analyse complex problems such as multiple hydraulic fractures and fracturing in heterogeneous media. However, majority of available models are restricted to single-phase flow through fracture and permeable porous rock. This is not compatible with actual field conditions where the injected fluid does not have similar properties as the host fluid. In this study we present a fully coupled hydro-poroelastic model which incorporates two fluids i.e. fracturing fluid and host fluid. Flow through fracture is defined based on lubrication assumption, while flow through matrix is defined as Darcy flow. The fracture discontinuity in the mechanical model is captured using eXtended Finite Element Method (XFEM while the fracture propagation criterion is defined through cohesive fracture model. The discontinuous matrix fluid velocity across fracture is modelled using leak-off loading which couples fracture flow and matrix flow. The proposed model has been discretised using standard Galerkin method, implemented in Matlab and verified against several published solutions. Multiple hydraulic fracturing simulations are performed to show the model robustness and to illustrate how problem parameters such as injection rate and rock permeability affect the hydraulic fracturing variables i.e. injection pressure, fracture aperture and fracture length. The results show the impact of partial saturation on leak-off and the fact that single-phase models may underestimate the leak-off.

  8. Oxygen isotope thermometry of quartz-Al2SiO5veins in high-grade metamorphic rocks on Naxos island (Greece)

    Science.gov (United States)

    Putlitz, Benita; Valley, John; Matthews, Alan; Katzir, Yaron

    2002-04-01

    Diffusion models predict that peak metamorphic temperatures are best recorded by the oxygen isotope fractionation between minerals in a bi-mineralic rock in which a refractory accessory mineral with slow oxygen diffusion rate is modally minor to a mineral with a faster diffusion rate. This premise is demonstrated for high-grade metamorphism on the island of Naxos, Greece, where quartz-kyanite oxygen isotope thermometry from veins in high-grade metamorphic pelites gives temperatures of 635-690 °C. These temperatures are in excellent agreement with independent thermometry for the regional M2 peak metamorphic conditions and show that the vein minerals isotopically equilibrated at the peak of metamorphism. Quartz-sillimanite fractionations in the same veins give similar temperatures (680+/-35 °C) and suggest that the veins grew near to the kyanite-sillimanite boundary, corresponding to pressures of 6.5 to 7.5 kbar for temperatures of 635-685 °C. By contrast, quartz-kyanite and quartz-biotite pairs in the host rocks yield lower temperature estimates than the veins (590-600 and 350-550 °C, respectively). These lower apparent temperatures are also predicted from calculations of diffusional resetting in the polyphase host-rock system. The data demonstrate that bimineralic vein assemblages can be used as accurate thermometers in high-temperature rocks whereas retrograde exchange remains a major problem in many polymineralic rocks.

  9. Molecular isotopic characterisation of hydrocarbon biomarkers in Palaeocene-Eocene evaporitic, lacustrine source rocks from the Jianghan Basin, China

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Grice, Kliti; Schouten, S.; Peters, Kenneth E.

    1998-01-01

    Immature organic matter in lacustrine source rocks from the Jianghan Basin, eastern China, was studied for distributions and stable carbon isotopic compositions (13C) of hydrocarbon biomarkers. All of the bitumens contain isorenieratane (13C ca. −17 ) indicating the presence of Chlorobiaceae, and

  10. 'Escher' Rock

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Chemical Changes in 'Endurance' Rocks [figure removed for brevity, see original site] Figure 1 This false-color image taken by NASA's Mars Exploration Rover Opportunity shows a rock dubbed 'Escher' on the southwestern slopes of 'Endurance Crater.' Scientists believe the rock's fractures, which divide the surface into polygons, may have been formed by one of several processes. They may have been caused by the impact that created Endurance Crater, or they might have arisen when water leftover from the rock's formation dried up. A third possibility is that much later, after the rock was formed, and after the crater was created, the rock became wet once again, then dried up and developed cracks. Opportunity has spent the last 14 sols investigating Escher, specifically the target dubbed 'Kirchner,' and other similar rocks with its scientific instruments. This image was taken on sol 208 (Aug. 24, 2004) by the rover's panoramic camera, using the 750-, 530- and 430-nanometer filters. The graph above shows that rocks located deeper into 'Endurance Crater' are chemically altered to a greater degree than rocks located higher up. This chemical alteration is believed to result from exposure to water. Specifically, the graph compares ratios of chemicals between the deep rock dubbed 'Escher,' and the more shallow rock called 'Virginia,' before (red and blue lines) and after (green line) the Mars Exploration Rover Opportunity drilled into the rocks. As the red and blue lines indicate, Escher's levels of chlorine relative to Virginia's went up, and sulfur down, before the rover dug a hole into the rocks. This implies that the surface of Escher has been chemically altered to a greater extent than the surface of Virginia. Scientists are still investigating the role water played in influencing this trend. These data were taken by the rover's alpha particle X-ray spectrometer.

  11. Alkaline rocks and the occurrence of uranium

    International Nuclear Information System (INIS)

    Hambleton-Jones, B.B.; Toens, P.D.

    1980-10-01

    Many alkaline complexes contain uranium and other minerals in low concentrations and are regarded as constituting valuable potential reserves. Certain complex metallurgical problems, however, remain to be solved. Alkaline rocks occur in a number of forms and environments and it is noted that they are generated during periods of geological quiescence emplaced mainly in stable aseismic areas. Many occur along the extensions of oceanic transform faults beneath the continental crust and the application of this concept to areas not currently known to host alkaline complexes may prove useful in identifying potential target areas for prospecting operations [af

  12. Testing new methodologies and assessing their potential for reservoir characterisation: Geoelectrical studies in the Northwest Carboniferous Basin (Ireland).

    Science.gov (United States)

    Ogaya, Xènia; Campanyà, Joan; Rath, Volker; Jones, Alan G.; Reay, Derek; Raine, Rob; McConnell, Brian; Ledo, Juanjo

    2016-04-01

    The overarching objective of this study is to improve our methods of characterising saline aquifers by integrating newly acquired electromagnetic data with existing geophysical and geological data. The work presented here is part of an ongoing project to evaluate Ireland's potential for onshore carbon sequestration (IRECCSEM; funded by Science Foundation Ireland). The methodology presented in this characterisation work is not only relevant for studying the potential for onshore carbon sequestration, but is generally applicable for aquifer characterisation, particularly for the evaluation of geothermal resources in appropriate geological settings. We present first results of the three-dimensional (3D) modelling and inversion of the magnetotelluric (MT) data acquired in the Northwest Carboniferous Basin (Ireland) in summer 2015. The electrical resistivity distribution beneath the survey area is constrained using a joint inversion of three different types of electromagnetic data: MT impedance tensor responses (Z), geomagnetic transfer functions (GTF) and inter-station horizontal magnetic transfer-functions (HMT). The preliminary 3D resistivity model obtained reveals the geoelectrical structure of the subsurface, which is translated into parameters relevant to fluid flow. The electromagnetic data were acquired along profiles linking four wells drilled in the area and the available well log data from those wells are used to evaluate some of the existing petrophysical relationships and calibrate them for the study area. This allows us to interpolate the rock physical properties from one well to another well, using the computed geoelectrical model as a reference. The obtained results are compared to available independent geological and geophysical data in order to analyse the validity of this technique, to characterise the uncertainties inherent to our approach, and to assess the potential of this methodology for reservoir characterisation.

  13. Diffusion and retention of organic anions in Callovian-Oxfordian clay rock

    International Nuclear Information System (INIS)

    Rasamimanana, Sabrina

    2016-01-01

    The Callovo-Oxfordian mud-stone (CO_x) is studied as a possible host rock for a deep disposal of radioactive waste (Cigeo project). Indeed, besides being very weakly permeable, it presents a high content of clayey minerals, capable of retaining radionuclides under cationic form and to delay strongly their transport. Nevertheless, some waste packages may release a significant amount of organic molecules, capable of complexing these radionuclides and drastically increase their mobility. So, the objective of this work was to better understand the diffusive behavior of several organic molecules of interest in this mudstone, by investigating at first their affinity with the host rock. The retention of organic molecules under anionic form (acetate, phthalate, adipate, benzoate, and citrate) was quantified on to the dispersed CO_x mudstone using adsorption/desorption batch experiments. Experiments on de-carbonated rock and clay fraction only (≤ 2μm) were also performed to identify solid phases and chemical functions responsible for the retention. a correlation of the intensity of retention, R_d, was pointed out whit the dipole moment μ(Orga.), providing a qualitative estimate of retention capacity for polar hydrophilic organic molecules. So, phthalate, slightly polar, displays a reversible retention (R_d ≅1,6 L.kg"-"1), mainly on clayey phases. Citrate, very polar and strongly adsorbed (R_d ≅ 40 L.kg"-"1), displays a persistent desorption hysteresis and an affinity to different solid phases (clayey minerals and minor oxides). Lastly, acetate, adipate and benzoate, weakly polar, display a lower affinity with rock (R_d ≤ 0,2 L.kg"-"1). The diffusive behavior in compact rock of these organic anions was then studied. The effective diffusion coefficient and retardation factor values were quantified. The low diffusivity, [D_e/D_0](Organic Anions) ≅ 0,1 a0,25 * [D_e/D_0](Water) evidences an effect of anionic exclusion, with a same intensity as that observed for

  14. Genomic characterisation of Wongabel virus reveals novel genes within the Rhabdoviridae.

    Science.gov (United States)

    Gubala, Aneta J; Proll, David F; Barnard, Ross T; Cowled, Chris J; Crameri, Sandra G; Hyatt, Alex D; Boyle, David B

    2008-06-20

    Viruses belonging to the family Rhabdoviridae infect a variety of different hosts, including insects, vertebrates and plants. Currently, there are approximately 200 ICTV-recognised rhabdoviruses isolated around the world. However, the majority remain poorly characterised and only a fraction have been definitively assigned to genera. The genomic and transcriptional complexity displayed by several of the characterised rhabdoviruses indicates large diversity and complexity within this family. To enable an improved taxonomic understanding of this family, it is necessary to gain further information about the poorly characterised members of this family. Here we present the complete genome sequence and predicted transcription strategy of Wongabel virus (WONV), a previously uncharacterised rhabdovirus isolated from biting midges (Culicoides austropalpalis) collected in northern Queensland, Australia. The 13,196 nucleotide genome of WONV encodes five typical rhabdovirus genes N, P, M, G and L. In addition, the WONV genome contains three genes located between the P and M genes (U1, U2, U3) and two open reading frames overlapping with the N and G genes (U4, U5). These five additional genes and their putative protein products appear to be novel, and their functions are unknown. Predictive analysis of the U5 gene product revealed characteristics typical of viroporins, and indicated structural similarities with the alpha-1 protein (putative viroporin) of viruses in the genus Ephemerovirus. Phylogenetic analyses of the N and G proteins of WONV indicated closest similarity with the avian-associated Flanders virus; however, the genomes of these two viruses are significantly diverged. WONV displays a novel and unique genome structure that has not previously been described for any animal rhabdovirus.

  15. Helminth burden and ecological factors associated with alterations in wild host gastrointestinal microbiota

    DEFF Research Database (Denmark)

    Newbold, Lindsay K.; Burthe, Sarah J.; Oliver, Anna E.

    2017-01-01

    Infection by gastrointestinal helminths of humans, livestock and wild animals is common, but the impact of such endoparasites on wild hosts and their gut microbiota represents an important overlooked component of population dynamics. Wild host gut microbiota and endoparasites occupy the same...... to quantify helminth infection in situ. Microbiota from the significantly distinct proventriculus (site of infection), cloacal and faecal gastrointestinal tract microbiomes were characterised using 16S rRNA gene-targeted high-throughput sequencing. We found increasingly strong associations between helminth...... infection and microbiota composition progressing away from the site of infection, observing a pronounced dysbiosis in microbiota when samples were partitioned into high- and low-burden groups. We posit this dysbiosis is predominately explained by helminths inducing an anti-inflammatory environment...

  16. Long Term Sorption Diffusion Experiment (LTDE-SD). Supporting laboratory program - Sorption diffusion experiments and rock material characterisation. With supplement of adsorption studies on intact rock samples from the Forsmark and Laxemar site investigations

    Energy Technology Data Exchange (ETDEWEB)

    Widestrand, Henrik; Byegaard, Johan; Selnert, Eva; Skaalberg, Mats; Hoeglund, Susanne; Gustafsson, Erik (Geosigma AB, Uppsala (Sweden))

    2010-12-15

    The LTDE-SD experiment, (Long Term Sorption Diffusion Experiment) aims at increasing the scientific knowledge of sorption and diffusion under in situ conditions and to provide data for performance and safety assessment calculations. In this report, performance and results of laboratory sorption and diffusion experiments and porosity investigations using site-specific crushed and intact rock materials are presented, including a geological and mineralogical characterization of the samples. A synthetic groundwater and a part of the radionuclide tracer cocktail that was used for the in situ experiment were used also in the laboratory experiments. 13 radionuclide tracers were analysed in the laboratory experiments. The method descriptions from SKB Site Investigations were applied in order to enable comparisons with Site Investigations data. The water saturation porosity of 10 unaltered matrix rock samples from KA3065A02 and A03 is 0.26 +- 0.08% and two fracture material samples show porosities of 2.4% and 5.2% respectively. 14C-methylmethacrylate impregnation (the PMMA-method) show that the unaltered rock matrix porosity is relatively homogeneous with grain boundary porosity, while the porosity of fracture samples is heterogeneous and have increased porosity up to more than 10% in some parts. Through-diffusion experiments using tritiated water (H3HO) give a matrix diffusivity in the range from 2.7centre dot10-14 to 6.5centre dot10-14 m2/s in four samples from KA3065A02 and A03. The results of the porosity and diffusion measurements are coherent in ranges with earlier LTDE-SD measurements and are also in line with the SKB Site Investigations results. In the batch sorption experiments using crushed rock material, two matrix rock samples of Aevroe granodiorite, one red-stained altered Aevroe granodiorite sample and two chlorite-calcite dominated fracture samples were analysed for three different size fractions as a function of time up to 186 days contact time. The

  17. Hydraulic gradients in rock aquifers

    International Nuclear Information System (INIS)

    Dahlblom, P.

    1992-05-01

    This report deals with fractured rock as a host for deposits of hazardous waste. In this context the rock, with its fractures containing moving groundwater, is called the geological barrier. The desired properties of the geological barrier are low permeability to water, low hydraulic gradients and ability to retain matter dissolved in the water. The hydraulic gradient together with the permeability and the porosity determines the migration velocity. Mathematical modelling of the migration involves calculation of the water flow and the hydrodynamic dispersion of the contaminant. The porous medium approach can be used to calculate mean flow velocities and hydrodynamic dispersion of a large number of fractures are connected, which means that a large volume have to be considered. It is assumed that the porous medium approach can be applied, and a number of idealized examples are shown. It is assumed that the groundwater table is replenished by percolation at a constant rate. One-dimensional analytical calculations show that zero hydraulic gradients may exist at relatively large distance from the coast. Two-dimensional numerical calculations show that it may be possible to find areas with low hydraulic gradients and flow velocities within blocks surrounded by areas with high hydraulic conductivity. (au)

  18. Origin of sandstone-hosted uranium deposits, Frome Embayment, South Australia

    International Nuclear Information System (INIS)

    Sanford, R.F.

    1985-01-01

    The formation of sandstone-hosted uranium deposits in the Frome Embayment of South Australia is largely a result of tectonic events possibly as old as the Archean. Uranium deposits of several types and ages in the region demonstrate the importance of uranium enrichment in the source area. Mobile zones around the Archean terrane of the Gawler block have been the locus of intermittent tectonic activity from Early Proterozoic to recent time. Vein-type uranium deposits in basement source rocks are concentrated in these zones, because they favor deep crustal partial melting and ascent of Na-rich granitic magmas and hydrothermal solutions. Relatively stable areas bordered by mobile zones, are important for the formation of sandstone-hosted uranium deposits because they act as platforms for terrigenous sedimentation from the surrounding, uplifted, uranium-rich basement rocks. Wet, subtropical conditions prevailing at the time of uplift aided rapid erosion and subaerial deposition of channel sands with intermixed organic detritus. Later uplift accompanied by erosion of the recently deposited sands in the headwater area caused increased recharge of oxygenated uraniferous ground water, which led to the formation of geochemical-cell roll-front type deposits like those in the Wyoming basins. Subsequent arid conditions helped preserve the deposits. (author)

  19. Reproducing early Martian atmospheric carbon dioxide partial pressure by modeling the formation of Mg-Fe-Ca carbonate identified in the Comanche rock outcrops on Mars

    Science.gov (United States)

    Berk, Wolfgang; Fu, Yunjiao; Ilger, Jan-Michael

    2012-10-01

    The well defined composition of the Comanche rock's carbonate (Magnesite0.62Siderite0.25Calcite0.11Rhodochrosite0.02) and its host rock's composition, dominated by Mg-rich olivine, enable us to reproduce the atmospheric CO2partial pressure that may have triggered the formation of these carbonates. Hydrogeochemical one-dimensional transport modeling reveals that similar aqueous rock alteration conditions (including CO2partial pressure) may have led to the formation of Mg-Fe-Ca carbonate identified in the Comanche rock outcrops (Gusev Crater) and also in the ultramafic rocks exposed in the Nili Fossae region. Hydrogeochemical conditions enabling the formation of Mg-rich solid solution carbonate result from equilibrium species distributions involving (1) ultramafic rocks (ca. 32 wt% olivine; Fo0.72Fa0.28), (2) pure water, and (3) CO2partial pressures of ca. 0.5 to 2.0 bar at water-to-rock ratios of ca. 500 molH2O mol-1rock and ca. 5°C (278 K). Our modeled carbonate composition (Magnesite0.64Siderite0.28Calcite0.08) matches the measured composition of carbonates preserved in the Comanche rocks. Considerably different carbonate compositions are achieved at (1) higher temperature (85°C), (2) water-to-rock ratios considerably higher and lower than 500 mol mol-1 and (3) CO2partial pressures differing from 1.0 bar in the model set up. The Comanche rocks, hosting the carbonate, may have been subjected to long-lasting (>104 to 105 years) aqueous alteration processes triggered by atmospheric CO2partial pressures of ca. 1.0 bar at low temperature. Their outcrop may represent a fragment of the upper layers of an altered olivine-rich rock column, which is characterized by newly formed Mg-Fe-Ca solid solution carbonate, and phyllosilicate-rich alteration assemblages within deeper (unexposed) units.

  20. Petroleum Characterisation and Reservoir Dynamics - The Froey Field and the Rind Discovery, Norwegian Continental Shelf

    Energy Technology Data Exchange (ETDEWEB)

    Bhullar, Abid G.

    1999-07-01

    The objective of this thesis is to apply the fundamental principles of petroleum geochemistry integrated with petroleum/reservoir engineering and geological concepts to the dynamics and characterisation of petroleum reservoirs. The study is based on 600 core samples and 9 DST oils from 11 wells in the Froey Field and the Rind Discovery. The work is presented in five papers. Paper 1 is a detailed characterisation of the reservoirs using a petroleum geochemical approach. Paper 2 describes the application of a single reservoir geochemical screening technique to exploration, appraisal and production geology and reservoir/petroleum engineering. Paper 3 compares the Iatroscan TLC-FID screening technique and the extraction efficiency of micro-extraction used in this work with the well-established Rock-Eval geochemical screening method and with the Soxtec extraction method. Paper 4 refines the migration and filling models of Paper 1, and Paper 5 presents a comparison of models of petroleum generation, migration and accumulation based on geochemical data with 1D burial history, a ''pseudo well'' based on actual well data and regional seismic analysis representing the hydrocarbon generative basin conditions.

  1. Rock fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Brown, W.S.; Green, S.J.; Hakala, W.W.; Hustrulid, W.A.; Maurer, W.C. (eds.)

    1976-01-01

    Experts in rock mechanics, mining, excavation, drilling, tunneling and use of underground space met to discuss the relative merits of a wide variety of rock fragmentation schemes. Information is presented on novel rock fracturing techniques; tunneling using electron beams, thermocorer, electric spark drills, water jets, and diamond drills; and rock fracturing research needs for mining and underground construction. (LCL)

  2. Characterisation, design and execution of two grouting fans at 450 m level, Aespoe HRL

    Energy Technology Data Exchange (ETDEWEB)

    Emmelin, Ann [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Eriksson, Magnus [Royal Inst. of Technology, Stockholm (Sweden); Fransson, Aasa [Chalmers Univ. of Technology, Goeteborg (Sweden)

    2004-09-01

    During June 2003 a grouting field experiment was carried out at Aespoe HRL, in connection with the construction of a tunnel (TASQ) for the Aespoe Pillar Stability Experiment (APSE). The tunnel is situated in connection to the elevator shaft landing at 450 m depth and runs in direction N/E. The grouting was carried out as part of the ordinary construction work, but was accompanied by extra investigations and analyses during operations and an active adaptation of a basic grouting design to the encountered conditions. The main objectives of this set-up were to Investigate what can be achieved with best available technology, material and knowledge under the current conditions, i.e. a relatively tight crystalline rock mass at great depth; Collect data and evaluate theories resulting from previous research projects on characterisation and predictions on grout spread; Collect data to further develop those above mentioned theories; Contribute to the achievement of good conditions at the experimental site for the pillar stability experiments. The characterization method is based on analyses of stepwise investigations consisting of investigations in an initially drilled core-drill hole followed by probe and grouting boreholes with pressure-build-up tests and measuring of inflow during drilling, all aiming at identifying the singular fractures that are to be sealed. The decision about grouting design is based on the successively up-dated rock description from the characterization and iterative selection and testing of grouting design and grout in a numeric model, resulting in an expected grout spread and sealing effect. Based on investigations and analysis of results from investigations of a core-drilled hole at the site, a basic design was set up, together with conditions for application. Probe boreholes covering the first anticipated fan gave substantially larger inflows than expected, and subsequently the design was changed. A first round was drilled and grouted, sealing

  3. Characterisation, design and execution of two grouting fans at 450 m level, Aespoe HRL

    International Nuclear Information System (INIS)

    Emmelin, Ann; Eriksson, Magnus; Fransson, Aasa

    2004-09-01

    During June 2003 a grouting field experiment was carried out at Aespoe HRL, in connection with the construction of a tunnel (TASQ) for the Aespoe Pillar Stability Experiment (APSE). The tunnel is situated in connection to the elevator shaft landing at 450 m depth and runs in direction N/E. The grouting was carried out as part of the ordinary construction work, but was accompanied by extra investigations and analyses during operations and an active adaptation of a basic grouting design to the encountered conditions. The main objectives of this set-up were to Investigate what can be achieved with best available technology, material and knowledge under the current conditions, i.e. a relatively tight crystalline rock mass at great depth; Collect data and evaluate theories resulting from previous research projects on characterisation and predictions on grout spread; Collect data to further develop those above mentioned theories; Contribute to the achievement of good conditions at the experimental site for the pillar stability experiments. The characterization method is based on analyses of stepwise investigations consisting of investigations in an initially drilled core-drill hole followed by probe and grouting boreholes with pressure-build-up tests and measuring of inflow during drilling, all aiming at identifying the singular fractures that are to be sealed. The decision about grouting design is based on the successively up-dated rock description from the characterization and iterative selection and testing of grouting design and grout in a numeric model, resulting in an expected grout spread and sealing effect. Based on investigations and analysis of results from investigations of a core-drilled hole at the site, a basic design was set up, together with conditions for application. Probe boreholes covering the first anticipated fan gave substantially larger inflows than expected, and subsequently the design was changed. A first round was drilled and grouted, sealing

  4. Oxygen isotope geochemistry of The Geysers reservoir rocks, California

    Energy Technology Data Exchange (ETDEWEB)

    Gunderson, Richard P.; Moore, Joseph N.

    1994-01-20

    Whole-rock oxygen isotopic compositions of Late Mesozoic graywacke, the dominant host rock at The Geysers, record evidence of a large liquid-dominated hydrothermal system that extended beyond the limits of the present steam reservoir. The graywackes show vertical and lateral isotopic variations that resulted from gradients in temperature, permeability, and fluid composition during this early liquid-dominated system. All of these effects are interpreted to have resulted from the emplacement of the granitic "felsite" intrusion 1-2 million years ago. The {delta}{sup 18}O values of the graywacke are strongly zoned around a northwest-southeast trending low located near the center of and similar in shape to the present steam system. Vertical isotopic gradients show a close relationship to the felsite intrusion. The {delta}{sup 18}O values of the graywacke decrease from approximately 15 per mil near the surface to 4-7 per mil 300 to 600 m above the intrusive contact. The {delta}{sup 18}O values then increase downward to 8-10 per mil at the felsite contact, thereafter remaining nearly constant within the intrusion itself. The large downward decrease in {delta}{sup 18}O values are interpreted to be controlled by variations in temperature during the intrusive event, ranging from 150{degree}C near the surface to about 425{degree}C near the intrusive contact. The upswing in {delta}{sup 18}O values near the intrusive contact appears to have been caused by lower rock permeability and/or heavier fluid isotopic composition there. Lateral variations in the isotopic distributions suggests that the effects of temperature were further modified by variations in rock permeability and/or fluid-isotopic composition. Time-integrated water:rock ratios are thought to have been highest within the central isotopic low where the greatest isotopic depletions are observed. We suggest that this region of the field was an area of high permeability within the main upflow zone of the liquid

  5. Exploration of the role of permeability and effective stress transfer effects on Earthquakes Migration in a Fault Zone induced by a Fluid Injection in the nearby host rock: Experimental and Numerical Result.

    Science.gov (United States)

    Tsopela, A.; Guglielmi, Y.; Donze, F. V.; De Barros, L.; Henry, P.; Castilla, R.; Gout, C.

    2016-12-01

    Although it has long been known that anthropogenic fluid injections can induce earthquakes, the mechanisms involved are still poorly understood and our ability to assess the seismic hazard associated to the production of geothermal energy or unconventional hydrocarbon remains limited. Here we present a field injection experiment conducted in the host rock 4m away from a fault affecting Toarcian shales (Tournemire massif, France). A dense network of sensors recorded fluid pressure, flow-rate, deformation and seismic activity. Injections followed an extended leak-off test protocol. Failure in the host rock was observed for a pressure of 4.4 MPa associated to a strike-slip-to-reverse reactivation of a pre-existing fracture. Magnitude -4.2 to -3.8 seismic events were located in the fault zone 3.5-to->10m away from the injection showing focal mechanisms in reasonable agreement with a strike-slip reactivation of the fault structures. We first used fully coupled hydro-mechanical numerical modeling to quantify the injection source parameters (state of stress, size of the rupture patch and size of the pressurized patch). We applied an injection loading protocol characterized by an imposed flow rate-vs-time history according to the volume of fluid injected in-situ, to match calculated and measured pressure and displacement variations at the injection source. We then used a larger model including the fault zone to discuss how predominant the effects of stress transfer mechanisms causing a purely mechanical fault activation can be compared to the effects of effective stress variations associated to fluid propagation in the fault structures. Preliminary results are that calculated slipping patches are much higher than the one estimated from seismicity, respectively 0.3m and <10-6m, and that the dimensions of the pressurized zone hardly matches with the distance of the earthquakes.

  6. Rock mechanics for hard rock nuclear waste repositories

    International Nuclear Information System (INIS)

    Heuze, F.E.

    1981-09-01

    The mined geologic burial of high level nuclear waste is now the favored option for disposal. The US National Waste Terminal Storage Program designed to achieve this disposal includes an extensive rock mechanics component related to the design of the wastes repositories. The plan currently considers five candidate rock types. This paper deals with the three hard rocks among them: basalt, granite, and tuff. Their behavior is governed by geological discontinuities. Salt and shale, which exhibit behavior closer to that of a continuum, are not considered here. This paper discusses both the generic rock mechanics R and D, which are required for repository design, as well as examples of projects related to hard rock waste storage. The examples include programs in basalt (Hanford/Washington), in granitic rocks (Climax/Nevada Test Site, Idaho Springs/Colorado, Pinawa/Canada, Oracle/Arizona, and Stripa/Sweden), and in tuff

  7. Elastic Rock Heterogeneity Controls Brittle Rock Failure during Hydraulic Fracturing

    Science.gov (United States)

    Langenbruch, C.; Shapiro, S. A.

    2014-12-01

    For interpretation and inversion of microseismic data it is important to understand, which properties of the reservoir rock control the occurrence probability of brittle rock failure and associated seismicity during hydraulic stimulation. This is especially important, when inverting for key properties like permeability and fracture conductivity. Although it became accepted that seismic events are triggered by fluid flow and the resulting perturbation of the stress field in the reservoir rock, the magnitude of stress perturbations, capable of triggering failure in rocks, can be highly variable. The controlling physical mechanism of this variability is still under discussion. We compare the occurrence of microseismic events at the Cotton Valley gas field to elastic rock heterogeneity, obtained from measurements along the treatment wells. The heterogeneity is characterized by scale invariant fluctuations of elastic properties. We observe that the elastic heterogeneity of the rock formation controls the occurrence of brittle failure. In particular, we find that the density of events is increasing with the Brittleness Index (BI) of the rock, which is defined as a combination of Young's modulus and Poisson's ratio. We evaluate the physical meaning of the BI. By applying geomechanical investigations we characterize the influence of fluctuating elastic properties in rocks on the probability of brittle rock failure. Our analysis is based on the computation of stress fluctuations caused by elastic heterogeneity of rocks. We find that elastic rock heterogeneity causes stress fluctuations of significant magnitude. Moreover, the stress changes necessary to open and reactivate fractures in rocks are strongly related to fluctuations of elastic moduli. Our analysis gives a physical explanation to the observed relation between elastic heterogeneity of the rock formation and the occurrence of brittle failure during hydraulic reservoir stimulations. A crucial factor for understanding

  8. Rock.XML - Towards a library of rock physics models

    Science.gov (United States)

    Jensen, Erling Hugo; Hauge, Ragnar; Ulvmoen, Marit; Johansen, Tor Arne; Drottning, Åsmund

    2016-08-01

    Rock physics modelling provides tools for correlating physical properties of rocks and their constituents to the geophysical observations we measure on a larger scale. Many different theoretical and empirical models exist, to cover the range of different types of rocks. However, upon reviewing these, we see that they are all built around a few main concepts. Based on this observation, we propose a format for digitally storing the specifications for rock physics models which we have named Rock.XML. It does not only contain data about the various constituents, but also the theories and how they are used to combine these building blocks to make a representative model for a particular rock. The format is based on the Extensible Markup Language XML, making it flexible enough to handle complex models as well as scalable towards extending it with new theories and models. This technology has great advantages as far as documenting and exchanging models in an unambiguous way between people and between software. Rock.XML can become a platform for creating a library of rock physics models; making them more accessible to everyone.

  9. Characterisation: Challenges and Opportunities - A UK Perspective

    International Nuclear Information System (INIS)

    Emptage, Matthew; Loudon, David; Mcleod, Richard; Milburn, Helen

    2016-01-01

    Characterisation plays a very important role in the nuclear industry supporting: the development and implementation of decommissioning strategies/plans (and the optimisation of associated costs through reduction in technical risks); regulatory compliance demonstration; waste prevention/minimisation; evaluation and optimisation of worker radiation doses; and maintaining public confidence. Recognising these important drivers, the UK regulators are working with the UK Nuclear Decommissioning Authority (NDA) to undertake a review of characterisation practice in the UK nuclear (decommissioning) industry. The objective of the characterisation review is to understand the current characterisation challenges and to determine strategic and tactical opportunities (including sharing of standards and guidance, capabilities, learning from experience, good practice, research and development, training, quality assurance) to optimise characterisation practice. The work is being undertaken through review of nuclear operator's characterisation practice, with input from the NDA, the UK regulators, nuclear operators and representatives from the supply chain, and through consideration of good practice case studies. To support this, a catalogue of relevant national/international guidance documents is also be compiled. Finally a workshop with representatives from all parties has taken place to consider the findings and establish a common understanding of challenges and opportunities and to start to consider how they can be addressed. The review is establishing a collective (UK regulator's, NDA; nuclear operator's and supply chain) understanding of opportunities to improve characterisation practice in the UK. The characterisation review process is described and early results are presented and discussed. Subsequent work in 2016 will be required to prioritise the opportunities and to build a consensus to facilitate development and implementation of an improvement plan. The aim

  10. Time dependency in the mechanical properties of crystalline rocks. A literature survey

    International Nuclear Information System (INIS)

    Hagros, A.; Johansson, E.; Hudson, J.A.

    2008-09-01

    Because of the long design life, elevated temperatures, and the location at depth (high stresses), time-dependent aspects of the mechanical properties of crystalline rock are potentially important for the design and the long term safety of the radioactive waste repository at Olkiluoto. However, time-dependent effects in rock mechanics are still one of the least understood aspects of the physical behaviour of rock masses, this being partly due to the fact that it is difficult to conduct long-term experimental tests - either in the laboratory or in situ. Yet, the time-dependent mechanical behaviour needs to be characterised so that it can be included in the modelling studies supporting repository design. The Introduction explains the background to the literature survey and includes definitions of the terms 'creep' (increasing strain at constant stress) and 'stress relaxation' (decreasing stress at constant strain). Moreover, it is noted that the rock around an in situ excavation is loaded by the adjacent rock elements and so the timedependent behaviour will depend on the unloading stiffness of these and hence will not actually be either pure creep or pure stress relaxation. The Appendix contains the results of the literature survey of reported time-dependent research as it applies to crystalline rock. A summary of each of the 38 literature items is presented in tabular form covering document number, subject area, document reference, subject matter, objectives, methodology, highlighted figures, conclusions and comments. It is concluded that the time-dependent failure strength of all rocks observed may be interpreted by sub-critical crack growth assisted by the stress corrosion mechanism. Also, certain parameters are known to affect the long-term properties: mineralogy, grain size, water/water chemistry, confining stress and loading history. At some point in the loading history of rock, the state of crack development reaches a point whereby the continued generation of

  11. Host specificity of turkey and chicken Eimeria: controlled cross-transmission studies and a phylogenetic view.

    Science.gov (United States)

    Vrba, Vladimir; Pakandl, Michal

    2015-03-15

    Protozoan parasites of the Eimeria genus have undergone extensive speciation and are now represented by a myriad of species that are specialised to different hosts. These species are highly host-specific and usually parasitise single host species, with only few reported exceptions. Doubts regarding the strict host specificity were frequent in the original literature describing coccidia parasitising domestic turkeys. The availability of pure characterised lines of turkey and chicken Eimeria species along with the recently developed quantitative PCR identification of these species allowed to investigate the issue of host specificity using well-controlled cross-transmission experiments. Seven species of gallinaceous birds (Gallus gallus, Meleagris gallopavo, Alectoris rufa, Perdix perdix, Phasianus colchicus, Numida meleagris and Colinus virginianus) were inoculated with six species and strains of turkey Eimeria and six species of chicken coccidia and production of oocysts was monitored. Turkey Eimeria species E. dispersa, E. innocua and E. meleagridis could complete their development in the hosts from different genera or even different families. Comparison of phylogenetic positions of these Eimeria species according to 18S rDNA and COI showed that the phylogeny cannot explain the observed patterns of host specificity. These findings suggest that the adaptation of Eimeria parasites to foreign hosts is possible and might play a significant role in the evolution and diversification of this genus. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Workshop on rock mechanics issues in repository design and performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-01

    The Center for Nuclear Waste Regulatory Analyses organized and hosted a workshop on ``Rock Mechanics Issues in Repository Design and Performance Assessment`` on behalf its sponsor the U.S. Nuclear Regulatory Commission (NRC). This workshop was held on September 19- 20, 1994 at the Holiday Inn Crowne Plaza, Rockville, Maryland. The objectives of the workshop were to stimulate exchange of technical information among parties actively investigating rock mechanics issues relevant to the proposed high-level waste repository at Yucca Mountain and identify/confirm rock mechanics issues important to repository design and performance assessment The workshop contained three technical sessions and two panel discussions. The participants included technical and research staffs representing the NRC and the Department of Energy and their contractors, as well as researchers from the academic, commercial, and international technical communities. These proceedings include most of the technical papers presented in the technical sessions and the transcripts for the two panel discussions. Selected papers have been indexed separately for inclusion the Energy Science and Technology Database.

  13. A Hydrous Seismogenic Fault Rock Indicating A Coupled Lubrication Mechanism

    Science.gov (United States)

    Okamoto, S.; Kimura, G.; Takizawa, S.; Yamaguchi, H.

    2005-12-01

    In the seismogenic subduction zone, the predominant mechanisms have been considered to be fluid induced weakening mechanisms without frictional melting because the subduction zone is fundamentally quite hydrous under low temperature conditions. However, recently geological evidence of frictional melting has been increasingly reported from several ancient accretionary prisms uplifted from seismogenic depths of subduction zones (Ikesawa et al., 2003; Austrheim and Andersen, 2004; Rowe et al., 2004; Kitamura et al., 2005) but relationship between conflicting mechanisms; e.g. thermal pressurization of fluid and frictional melting is still unclear. We found a new exposure of pseudotachylyte from a fossilized out-of-sequence thrust (OOST) , Nobeoka thrust in the accretionary complex, Kyushu, southwest Japan. Hanging-wall and foot-wall are experienced heating up to maximum temperature of about 320/deg and about 250/deg, respectively. Hanging-wall rocks of the thrust are composed of shales and sandstones deformed plastically. Foot-wall rocks are composed of shale matrix melange with sandstone and basaltic blocks deformed in a brittle fashion (Kondo et al, 2005). The psudotachylyte was found from one of the subsidiary faults in the hanging wall at about 10 m above the fault core of the Nobeoka thrust. The fault is about 1mm in width, and planer rupture surface. The fault maintains only one-time slip event because several slip surfaces and overlapped slip textures are not identified. The fault shows three deformation stages: The first is plastic deformation of phyllitic host rocks; the second is asymmetric cracking formed especially in the foot-wall of the fault. The cracks are filled by implosion breccia hosted by fine carbonate minerals; the third is frictional melting producing pseudotachylyte. Implosion breccia with cracking suggests that thermal pressurization of fluid and hydro-fracturing proceeded frictional melting.

  14. Rock burst governance of working face under igneous rock

    Science.gov (United States)

    Chang, Zhenxing; Yu, Yue

    2017-01-01

    As a typical failure phenomenon, rock burst occurs in many mines. It can not only cause the working face to cease production, but also cause serious damage to production equipment, and even result in casualties. To explore how to govern rock burst of working face under igneous rock, the 10416 working face in some mine is taken as engineering background. The supports damaged extensively and rock burst took place when the working face advanced. This paper establishes the mechanical model and conducts theoretical analysis and calculation to predict the fracture and migration mechanism and energy release of the thick hard igneous rock above the working face, and to obtain the advancing distance of the working face when the igneous rock fractures and critical value of the energy when rock burst occurs. Based on the specific conditions of the mine, this paper put forward three kinds of governance measures, which are borehole pressure relief, coal seam water injection and blasting pressure relief.

  15. Characterising and modelling the excavation damaged zone (EDZ) in crystalline rock in the context of radioactive waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Hudson, J.A.; Backstrom, A.; Rutqvist, J.; Jing, L.; Backers, T.; Chijimatsu, M.; Christiansson, R.; Feng, X.-T.; Kobayashi, A.; Koyama, T.; Lee, H.-S.; Neretnieks, I.; Pan, P.Z.; Rinne, M.; Shen, B.-T.

    2008-10-01

    This paper describes current knowledge about the nature of and potential for thermo-hydro-mechanical-chemical modelling of the Excavation Damaged Zone (EDZ) around the excavations for an underground radioactive waste repository. In the first part of the paper, the disturbances associated with excavation are explained, together with reviews of Workshops that have been held on the subject. In the second part of the paper, the results of a DECOVALEX research programme on modelling the EDZ are presented. Four research teams used four different models to simulate the complete stress-strain curve for Avro granite from the Swedish Aespoe Hard Rock Laboratory. Subsequent research extended the work to computer simulation of the evolution of the repository using a 'wall block model' and a 'near-field model'. This included assessing the evolution of stress, failure and permeability and time dependent effects during repository evolution. As discussed, all the computer models are well suited to sensitivity studies for evaluating the influence of their respective supporting parameters on the complete stress-strain curve for rock and for modelling the EDZ.

  16. Hydrothermal alteration styles in ancient and modern orogenic gold deposits, New Zealand

    International Nuclear Information System (INIS)

    Craw, D.; Upton, P.; MacKenzie, D.J.

    2009-01-01

    Orogenic hydrothermal systems in the South Island of New Zealand were active during Mesozoic and late Cenozoic collisional deformation and metamorphism of greywacke/schist terranes. Observations on the currently active mountain-building environment yield insights on processes occurring in the upper 5-15 km of the crust, and observations on an adjacent lithologically identical exhumed ancient mountain belt provide information on processes at 10-20 km in the crust. Hydrothermal fluids were mainly derived from metamorphic dehydration reactions and/or circulating topographically driven meteoric water in these mountain belts. Three geochemically and mineralogically different types of hydrothermal alteration and vein mineralisation occurred in these orogenic belts, and gold enrichment (locally economic) occurred in some examples of each of these three types. The first type of alteration involved fluids that were in or near chemical equilibrium with their greenschist facies host rocks. Fluid flow was controlled by discontinuous fractures, and by microshears and grain boundaries in host rocks, in zones from metres to hundreds of metres thick. Vein and alteration mineralogy was similar to that of the host rocks, and included calcite and chlorite. The second type of alteration occurred where the fluids were in distinct disequilibrium with the host rocks. Fracture permeability was important for fluid flow, but abundant host rock alteration occurred as well. The alteration zones were characterised by decomposition of chlorite and replacement by ankeritic carbonate in zones up to tens of metres thick. The mineralising fluid was deep-sourced and initially rock-equilibrated, with some meteoric input. The third type of mineralisation was controlled almost exclusively by fracture permeability, and host rock alteration was minor (centimetre scale). This mineralisation type commonly involved calcite and chlorite as vein and alteration minerals, and mineralisation fluids had a major

  17. The feeding tube of cyst nematodes: characterisation of protein exclusion.

    Directory of Open Access Journals (Sweden)

    Sebastian Eves-van den Akker

    Full Text Available Plant parasitic nematodes comprise several groups; the most economically damaging of these are the sedentary endoparasites. Sedentary endoparasitic nematodes are obligate biotrophs and modify host root tissue, using a suite of effector proteins, to create a feeding site that is their sole source of nutrition. They feed by withdrawing host cell assimilate from the feeding site though a structure known as the feeding tube. The function, composition and molecular characteristics of feeding tubes are poorly characterised. It is hypothesised that the feeding tube facilitates uptake of host cell assimilate by acting as a molecular sieve. Several studies, using molecular mass as the sole indicator of protein size, have given contradictory results about the exclusion limits of the cyst nematode feeding tube. In this study we propose a method to predict protein size, based on protein database coordinates in silico. We tested the validity of these predictions using travelling wave ion mobility spectrometry--mass spectrometry, where predictions and measured values were within approximately 6%. We used the predictions, coupled with mass spectrometry, analytical ultracentrifugation and protein electrophoresis, to resolve previous conflicts and define the exclusion characteristics of the cyst nematode feeding tube. Heterogeneity was tested in the liquid, solid and gas phase to provide a comprehensive evaluation of three proteins of particular interest to feeding tube size exclusion, GFP, mRFP and Dual PI. The data and procedures described here could be applied to the design of plant expressed defence compounds intended for uptake into cyst nematodes. We also highlight the need to assess protein heterogeneity when creating novel fusion proteins.

  18. The feeding tube of cyst nematodes: characterisation of protein exclusion.

    Science.gov (United States)

    Eves-van den Akker, Sebastian; Lilley, Catherine J; Ault, James R; Ashcroft, Alison E; Jones, John T; Urwin, Peter E

    2014-01-01

    Plant parasitic nematodes comprise several groups; the most economically damaging of these are the sedentary endoparasites. Sedentary endoparasitic nematodes are obligate biotrophs and modify host root tissue, using a suite of effector proteins, to create a feeding site that is their sole source of nutrition. They feed by withdrawing host cell assimilate from the feeding site though a structure known as the feeding tube. The function, composition and molecular characteristics of feeding tubes are poorly characterised. It is hypothesised that the feeding tube facilitates uptake of host cell assimilate by acting as a molecular sieve. Several studies, using molecular mass as the sole indicator of protein size, have given contradictory results about the exclusion limits of the cyst nematode feeding tube. In this study we propose a method to predict protein size, based on protein database coordinates in silico. We tested the validity of these predictions using travelling wave ion mobility spectrometry--mass spectrometry, where predictions and measured values were within approximately 6%. We used the predictions, coupled with mass spectrometry, analytical ultracentrifugation and protein electrophoresis, to resolve previous conflicts and define the exclusion characteristics of the cyst nematode feeding tube. Heterogeneity was tested in the liquid, solid and gas phase to provide a comprehensive evaluation of three proteins of particular interest to feeding tube size exclusion, GFP, mRFP and Dual PI. The data and procedures described here could be applied to the design of plant expressed defence compounds intended for uptake into cyst nematodes. We also highlight the need to assess protein heterogeneity when creating novel fusion proteins.

  19. CUMULATE ROCKS ASSOCIATED WITH CARBONATE ASSIMILATION, HORTAVÆR COMPLEX, NORTH-CENTRAL NORWAY

    Science.gov (United States)

    Barnes, C. G.; Prestvik, T.; Li, Y.

    2009-12-01

    The Hortavær igneous complex intruded high-grade metamorphic rocks of the Caledonian Helgeland Nappe Complex at ca. 466 Ma. The complex is an unusual mafic-silicic layered intrusion (MASLI) because the principal felsic rock type is syenite and because the syenite formed in situ rather than by deep-seated partial melting of crustal rocks. Magma differentiation in the complex was by assimilation, primarily of calc-silicate rocks and melts with contributions from marble and semi-pelites, plus fractional crystallization. The effect of assimilation of calcite-rich rocks was to enhance stability of fassaitic clinopyroxene at the expense of olivine, which resulted in alkali-rich residual melts and lowering of silica activity. This combination of MASLI-style emplacement and carbonate assimilation produced three types of cumulate rocks: (1) Syenitic cumulates formed by liquid-crystal separation. As sheets of mafic magma were loaded on crystal-rich syenitic magma, residual liquid was expelled, penetrating the overlying mafic sheets in flame structures, and leaving a cumulate syenite. (2) Reaction cumulates. Carbonate assimilation, illustrated by a simple assimilation reaction: olivine + calcite + melt = clinopyroxene + CO2 resulted in cpx-rich cumulates such as clinopyroxenite, gabbro, and mela-monzodiorite, many of which contain igneous calcite. (3) Magmatic skarns. Calc-silicate host rocks underwent partial melting during assimilation, yielding a Ca-rich melt as the principal assimilated material and permitting extensive reaction with surrounding magma to form Kspar + cpx + garnet-rich ‘cumulate’ rocks. Cumulate types (2) and (3) do not reflect traditional views of cumulate rocks but instead result from a series of melt-present discontinuous (peritectic) reactions and partial melting of calc-silicate xenoliths. In the Hortavær complex, such cumulates are evident because of the distinctive peritectic cumulate assemblages. It is unclear whether assimilation of

  20. Characterisation

    Science.gov (United States)

    2007-03-01

    Characterisation. In Nanotechnology Aerospace Applications – 2006 (pp. 4-1 – 4-8). Educational Notes RTO-EN-AVT-129bis, Paper 4. Neuilly-sur-Seine, France: RTO...the Commercialisation Processes Concept IDEA Proof-of- Principle Trial Samples Engineering Verification Samples Design Verification Samples...SEIC Systems Engineering for commercialisation Design Houses, Engineering & R&D USERS & Integrators SE S U R Integrators Fabs & Wafer Processing Die

  1. Review of potential host rocks for radioactive waste disposal in the southeast United States: Southeastern Coastal Plain Subregion

    International Nuclear Information System (INIS)

    1980-10-01

    A literature review was made of the geological characteristics of the Southeastern Coastal Plain physiograhic province in the states of Maryland, Virginia, North Carolina, South Carolina, and Georgia. The purpose of this study was to identify candidate exploration areas for the possible location of a mined repository for the storage of radioactive waste in the argillaceous sedimentary rocks of the Coastal Plain. Candidate areas were selected on the basis of geological characteristics, available subsurface data, and generally accepted requirements for waste isolation developed by previous studies. Factors considered in the evaluation include the stratigraphy and lithology, geologic history, structure, seismicity, hydrogeology, and natural resources of the candidate area. Unlike other potential regions, the Southeastern Coastal Plain is not composed of competent rock, but consists primarily of unconsolidated and water-saturated sediments overlying a basement of crystalline and metavolcanic rocks. Thus, construction of both shafts and tunnels to depths of approx. 1000 meters may encounter difficulties. Socio-economic and construction considerations have not been addressed in the evaluation. Based on the applied criteria, four areas were selected as being most favorable for future field investigation. These include one in Maryland, one in North Carolina, and two in Georgia

  2. Factors controlling Li concentration and isotopic composition in formation waters and host rocks of Marcellus Shale, Appalachian Basin

    Science.gov (United States)

    Phan, Thai T.; Capo, Rosemary C; Stewart, Brian W.; Macpherson, Gwen; Rowan, Elisabeth L.; Hammack, Richard W.

    2015-01-01

    In this study, water and whole rock samples from hydraulically fractured wells in the Marcellus Shale (Middle Devonian), and water from conventional wells producing from Upper Devonian sandstones were analyzed for lithium concentrations and isotope ratios (δ7Li). The distribution of lithium concentrations in different mineral groups was determined using sequential extraction. Structurally bound Li, predominantly in clays, accounted for 75-91 wt. % of total Li, whereas exchangeable sites and carbonate cement contain negligible Li (< 3%). Up to 20% of the Li is present in the oxidizable fraction (organic matter and sulfides). The δ7Li values for whole rock shale in Greene Co., Pennsylvania, and Tioga Co., New York, ranged from -2.3 to + 4.3‰, similar to values reported for other shales in the literature. The δ7Li values in shale rocks with stratigraphic depth record progressive weathering of the source region; the most weathered and clay-rich strata with isotopically light Li are found closest to the top of the stratigraphic section. Diagenetic illite-smectite transition could also have partially affected the bulk Li content and isotope ratios of the Marcellus Shale.

  3. Numerical simulation for the coupled thermo-mechanical performance of a lined rock cavern for underground compressed air energy storage

    Science.gov (United States)

    Zhou, Shu-Wei; Xia, Cai-Chu; Zhao, Hai-Bin; Mei, Song-Hua; Zhou, Yu

    2017-12-01

    Compressed air energy storage (CAES) is a technology that uses compressed air to store surplus electricity generated from low power consumption time for use at peak times. This paper presents a thermo-mechanical modeling for the thermodynamic and mechanical responses of a lined rock cavern used for CAES. The simulation was accomplished in COMSOL Multiphysics and comparisons of the numerical simulation and some analytical solutions validated the thermo-mechanical modeling. Air pressure and temperatures in the sealing layer and concrete lining exhibited a similar trend of ‘up-down-down-up’ in one cycle. Significant temperature fluctuation occurred only in the concrete lining and sealing layer, and no strong fluctuation was observed in the host rock. In the case of steel sealing, principal stresses in the sealing layer were larger than those in the concrete and host rock. The maximum compressive stresses of the three layers and the displacement on the cavern surface increased with the increase of cycle number. However, the maximum tensile stresses exhibited the opposite trend. Polymer sealing achieved a relatively larger air temperature and pressure compared with steel and air-tight concrete sealing. For concrete layer thicknesses of 0 and 0.1 m and an initial air pressure of 4.5 MPa, the maximum rock temperature could reach 135 °C and 123 °C respectively in a 30 day simulation.

  4. Geology of dolomite-hosted uranium deposits at the Pitch Mine, Saguache County, Colorado

    International Nuclear Information System (INIS)

    Nash, J.T.

    1981-01-01

    Newly documented uranium ore in the Pitch mine occurs chiefly in brecciated Mississippian Leadville Dolomite along the Chester upthrust zone, and to a lesser extent in sandstone, siltstone, and carbonaceous shale of the Pennsylvanian Belden Formation and in Precambrian granitic rocks and schist. Uranium-mineralized zones are generally thicker, more consistent, and of higher grade in dolomite than in other hosts, and roughly 50 percent of the new reserves are in dolomite. Strong physical control by dolomite is evident, as this is the only rock type that is pervasively brecciated within the fault slices that make up the footwall of the reverse-fault zone. Other rocks tended to either remain unbroken or undergo ductile deformation. Chemical controls on uranium deposition are subtle and appear chiefly to involve coprecipitation of FeS 2 as pyrite and marcasite, suggesting that sulfide ion may be the reductant

  5. The geology, structure and mineralisation of the Oyu Tolgoi porphyry copper-gold-molybdenum deposits, Mongolia: A review

    Directory of Open Access Journals (Sweden)

    T.M. (Mike Porter

    2016-05-01

    Mineralisation is characterised by varying, telescoped stages of intrusion and alteration. Early A-type quartz veined dykes were followed by Cu-Au mineralisation associated with potassic alteration, mainly K-feldspar in quartz-monzodiorite and biotite-magnetite in basaltic hosts. Downward reflux of cooled, late-magmatic hydrothermal fluid resulted in intense quartz-sericite retrograde alteration in the upper parts of the main syn-mineral intrusions, and an equivalent chlorite-muscovite/illite-hematite assemblage in basaltic host rocks. Uplift, facilitated by syn-mineral longitudinal faulting, brought sections of the porphyry deposit to shallower depths, to be overprinted and upgraded by late stage, shallower, advanced argillic alteration and high sulphidation mineralisation. Key controls on the location, size and grade of the deposit cluster include (i a long-lived, narrow faulted corridor; (ii multiple pulses of overlapping intrusion within the same structure; and (iii enclosing reactive, mafic dominated wall rocks, focussing ore.

  6. For Those About to Rock : Naislaulajat rock-genressä

    OpenAIRE

    Herranen, Linda

    2015-01-01

    For those about to rock – naislaulajat rock-genressä antaa lukijalleen kokonaisvaltaisen käsityksen naisista rock-genressä: rockin historiasta, sukupuolittuneisuudesta, seksismistä, suomalaisten naislaulajien menestyksestä. Työn aineisto on koottu aihepiirin kirjallisuudesta ja alalla toimiville naislaulajille teetettyjen kyselyiden tuloksista. Lisäksi avaan omia kokemuksiani ja ajatuksiani, jotta näkökulma naisista rock-genressä tulisi esille mahdollisimman monipuolisesti. Ajatus aihees...

  7. Proceedings of the 3. Canada-US rock mechanics symposium and 20. Canadian rock mechanics symposium : rock engineering 2009 : rock engineering in difficult conditions

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    This conference provided a forum for geologists, mining operators and engineers to discuss the application of rock mechanics in engineering designs. Members of the scientific and engineering communities discussed challenges and interdisciplinary elements involved in rock engineering. New geological models and methods of characterizing rock masses and ground conditions in underground engineering projects were discussed along with excavation and mining methods. Papers presented at the conference discussed the role of rock mechanics in forensic engineering. Geophysics, geomechanics, and risk-based approaches to rock engineering designs were reviewed. Issues related to high pressure and high flow water conditions were discussed, and new rock physics models designed to enhance hydrocarbon recovery were presented. The conference featured 84 presentations, of which 9 have been catalogued separately for inclusion in this database. tabs., figs.

  8. Influence of natural mobile organic matter on europium retention on Bure clay rock

    International Nuclear Information System (INIS)

    Vu-Do, Laurence

    2013-01-01

    Bure clay rock (CR) was chosen as host rock for the French high and intermediate level long lived radioactive waste repository. This choice is mostly explained by the retention ability of the Callovo-Oxfordian rock (COx). Bure clay rock contains natural organic matter (OM) that could have an influence on radionuclide retention. The aim of this work is to assess the influence of natural mobile OM on the retention of Eu on clay rock. Eu was chosen as a chemical model for trivalent actinides contained in vitrified waste. Three organic molecules were studied: suberic, sorbic and tiglic acids, small organic acids identified in COx pore water. All the experiments were carried out in an environment recreating COx water (pH=7.5; I=0.1 mol/L; PCO 2 =10 -2 bar).Clay rock sample characterization showed that the sample used in this work was similar to those previously extracted from the area of interest and that it was necessary to maintain pH at 7.5 to avoid altering the clay rock. The Eu-OM system study indicated that organic acids had no influence on Eu speciation in COx water. The Eu-CR system experimental study confirmed that retention implied sorption on CR (C(Eu)≤6.10 -6 mol/L) and precipitation in COx water (C(Eu)≥6.10 -6 mol/L). Distribution coefficient Rd (quantifying sorption) was estimated at 170 ± 30 L/g. This high value is consistent with literature values obtained on clay rocks. The ternary Eu-OM-CR system study showed a slight increase of sorption in the presence of organic matter. This synergistic effect is very satisfactory in terms of storage security: the presence of small organic acids in clay rock does not question retention properties with respect to europium and trivalent actinides. (author)

  9. Release consequence analysis for a hypothetical geologic radioactive waste repository in hard rock

    International Nuclear Information System (INIS)

    1979-12-01

    This report makes an evaluation of the long-term behaviour of the wastes placed in a hard rock repository. Impacts were analyzed for the seven reference fuel cycles of WG 7. The reference repository for this study is for granitic rock or gneiss as the host rock. The descriptions of waste packages and repository facilities used in this study represent only one of many possible designs based on the multiple barriers concept. The repository's size is based on a nuclear economy producing 100 gigawatts of electricity per year for 1 year. The objective of the modeling efforts presented in this study is to predict the rate of transport of radioactive contaminants from the repository through the geosphere to the biosphere and thus determine an estimate of the potential dose to humans so that the release consequence impacts of the various fuel cycles can be compared. Currently available hydrologic, leach, transport, and dose models were used in this study

  10. Art Rocks with Rock Art!

    Science.gov (United States)

    Bickett, Marianne

    2011-01-01

    This article discusses rock art which was the very first "art." Rock art, such as the images created on the stone surfaces of the caves of Lascaux and Altimira, is the true origin of the canvas, paintbrush, and painting media. For there, within caverns deep in the earth, the first artists mixed animal fat, urine, and saliva with powdered minerals…

  11. Peralkaline- and calc-alkaline-hosted volcanogenic massive sulfide deposits of the Bonnifield District, East-Central Alaska

    Science.gov (United States)

    Dusel-Bacon, Cynthia; Foley, Nora K.; Slack, John E.; Koenig, Alan E.; Oscarson, Robert L.

    2012-01-01

    Volcanogenic massive sulfide (VMS) Zn-Pb-Cu-Ag-Au deposits of the Bonnifield mining district formed during Late Devonian-Early Mississippian magmatism along the western edge of Laurentia. The largest deposits, Dry Creek and WTF, have a combined resource of 5.7 million tonnes at 10% Zn, 4% Pb, 0.3% Cu, 300 grams per tonne (g/t) Ag, and 1.6 g/t Au. These polymetallic deposits are hosted in high field strength element (HFSE)- and rare-earth element (REE)-rich peralkaline (pantelleritic) metarhyolite, and interlayered pyritic argillite and mudstone of the Mystic Creek Member of the Totatlanika Schist Formation. Mystic Creek metarhyolite and alkali basalt (Chute Creek Member) constitute a bimodal pair that formed in an extensional environment. A synvolcanic peralkaline quartz porphyry containing veins of fluorite, sphalerite, pyrite, and quartz intrudes the central footwall at Dry Creek. The Anderson Mountain deposit, located ~32 km to the southwest, occurs within calc-alkaline felsic to intermediate-composition metavolcanic rocks and associated graphitic argillite of the Wood River assemblage. Felsic metavolcanic rocks there have only slightly elevated HFSEs and REEs. The association of abundant graphitic and siliceous argillite with the felsic volcanic rocks together with low Cu contents in the Bonnifield deposits suggests classification as a siliciclastic-felsic type of VMS deposit. Bonnifield massive sulfides and host rocks were metamorphosed and deformed under greenschist-facies conditions in the Mesozoic. Primary depositional textures, generally uncommon, consist of framboids, framboidal aggregates, and spongy masses of pyrite. Sphalerite, the predominant base metal sulfide, encloses early pyrite framboids. Galena and chalcopyrite accompanied early pyrite formation but primarily formed late in the paragenetic sequence. Silver-rich tetrahedrite is a minor late phase at the Dry Creek deposit. Gold and Ag are present in low to moderate amounts in pyrite from all of

  12. Deformation and transport processes in salt rocks : An experimental study exploring effects of pressure and stress relaxation

    NARCIS (Netherlands)

    Muhammad, Nawaz

    2015-01-01

    The presence of evaporitic formations in sedimentary basins, often dominated by the salt mineral halite, is of great influence on the structural style developed during tectonic events. On a somewhat smaller scale, salt rocks often host a variety of deep solution mined caverns, which are increasingly

  13. Geological history and its impact on the rock mechanics properties of the Olkiluoto site

    International Nuclear Information System (INIS)

    Hudson, J.A.; Cosgrove, J.W.

    2006-03-01

    This report is one of three documents with background information for supporting the development of Posiva's future rock mechanics programme. The other two reports are a summary of all the rock mechanics work completed for Posiva before 2005 (Posiva Working Report) and a technical audit of the numerical modeling work that has been conducted previously for Posiva (REC Memo). The purpose of this report is to establish the extent to which the mechanical properties of the rocks at the Olkiluoto site can be estimated from a knowledge of the geological environment. The main information required for rock mechanics studies of the site is a knowledge of the prevailing stress state, the properties of the intact rock, and the properties of the fractures at all scales - from sizes that could form blocks in the tunnel roof up to the major brittle deformation zones that could be influence the location of the ONKALO and the subsequent repository. Thus, the summary of the geological history in Chapter 2 concentrates on these features and we summarise the ductile and brittle deformational tectonic history of the site, with emphasis on the inferred stress states causing the deformations. Then, in Chapter 3, the rock stress, the hierarchy of brittle fracturing, the fracture properties and the mechanical properties of the rock mass are considered in the light of the geological environment. These features provide the baseline knowledge of the host rock from which the logic of the future rock mechanics programme can be developed, based on: the bedrock model; the site investigation results; the requirements for generating the site descriptive model; the prediction-outcome ONKALO studies; and numerically modeling the effects of excavation for design and safety analysis. The implications of this study for the future rock mechanics work are outlined in Chapter 4 with emphasis on the key features for modeling. (orig.)

  14. An extended characterisation theorem for quantum logics

    International Nuclear Information System (INIS)

    Sharma, C.S.; Mukherjee, M.K.

    1977-01-01

    Two theorems are proved. In the first properties of an important mapping from an orthocomplemented lattice to itself are studied. In the second the characterisation theorem of Zierler (Pacific J. Math.; 11:1151 (1961)) is extended to obtain a very useful theorem characterising orthomodular lattices. Since quantum logics are merely sigma-complete orthomodular lattices, the principal result is, for application in quantum physics, a characterisation theorem for quantum logics. (author)

  15. Advances in elemental imaging of rocks using the AGLAE external microbeam

    Energy Technology Data Exchange (ETDEWEB)

    Calligaro, T., E-mail: thomas.calligaro@culture.gouv.fr [Centre de Recherche et de Restauration des musees de France, CNRS UMR171, Palais du Louvre, 75001 Paris (France); Coquinot, Y.; Pichon, L.; Moignard, B. [Centre de Recherche et de Restauration des musees de France, CNRS UMR171, Palais du Louvre, 75001 Paris (France)

    2011-10-15

    Rocks are widely represented in cultural heritage materials. They constitute the major part of archaeological artefacts like stone carvings, tools and weapons, and are present in art works in various forms, such as precious stone inlays or paint pigments. The study of such geomaterials, which are usually constituted of a complex aggregate of mineral phases, aims at determining their exact nature, their provenance and at understanding their possible alteration. Since minerals are often composed of light elements, IBA techniques such as PIXE and PIGE, thanks to their ability to measure with high sensitivity elements down to lithium, should be well adapted to their analysis. However, the bulk composition classically obtained using macro-IBA on pelletized samples or using a broad beam hides the multi-phased nature of the rocks and considerably blurs the searched chemical fingerprint. In contrast, the small size of a nuclear microprobe allows imaging the chemical composition at a finer scale and, when implemented in air, appears ideally suited to analyse without sampling these often precious items. This paper illustrates chemical micro-imaging of rocks with examples performed with the AGLAE external nuclear microprobe: characterisation of microscopic inclusions in gems and detailed chemical mapping of rocks with special emphasis to lapis lazuli. Lapis lazuli is of particular interest in both archaeology and art history: after being employed in Asia since the 7th millennium BC to make carvings and beads, it was used in Medieval Europe as a precious blue painting pigment known as ultramarine. The chemical imaging of major and trace elements in lapis lazuli using external {mu}-PIXE has permitted to identify its mineral phases, to assign their trace elements and to evidence undetected elements. In combination with {mu}-XRD and {mu}-Raman spectrometry, this approach provides a clear mineralogical fingerprint useful to determine rock provenance and to authenticate artefacts

  16. Advances in elemental imaging of rocks using the AGLAE external microbeam

    International Nuclear Information System (INIS)

    Calligaro, T.; Coquinot, Y.; Pichon, L.; Moignard, B.

    2011-01-01

    Rocks are widely represented in cultural heritage materials. They constitute the major part of archaeological artefacts like stone carvings, tools and weapons, and are present in art works in various forms, such as precious stone inlays or paint pigments. The study of such geomaterials, which are usually constituted of a complex aggregate of mineral phases, aims at determining their exact nature, their provenance and at understanding their possible alteration. Since minerals are often composed of light elements, IBA techniques such as PIXE and PIGE, thanks to their ability to measure with high sensitivity elements down to lithium, should be well adapted to their analysis. However, the bulk composition classically obtained using macro-IBA on pelletized samples or using a broad beam hides the multi-phased nature of the rocks and considerably blurs the searched chemical fingerprint. In contrast, the small size of a nuclear microprobe allows imaging the chemical composition at a finer scale and, when implemented in air, appears ideally suited to analyse without sampling these often precious items. This paper illustrates chemical micro-imaging of rocks with examples performed with the AGLAE external nuclear microprobe: characterisation of microscopic inclusions in gems and detailed chemical mapping of rocks with special emphasis to lapis lazuli. Lapis lazuli is of particular interest in both archaeology and art history: after being employed in Asia since the 7th millennium BC to make carvings and beads, it was used in Medieval Europe as a precious blue painting pigment known as ultramarine. The chemical imaging of major and trace elements in lapis lazuli using external μ-PIXE has permitted to identify its mineral phases, to assign their trace elements and to evidence undetected elements. In combination with μ-XRD and μ-Raman spectrometry, this approach provides a clear mineralogical fingerprint useful to determine rock provenance and to authenticate artefacts of

  17. A giant oil seep at a salt-induced escarpment of the São Paulo Plateau, Espírito Santo Basin, off Brazil: Host rock characteristics and geochemistry

    Science.gov (United States)

    Freire, Antonio Fernando Menezes; Iemini, Juliana Andrade; Viana, Adriano Roessler; Magnavita, Luciano Portugal; Dehler, Nolan Maia; Kowsmann, Renato Oscar; Miller, Dennis James; Bezerra, Sabrina Helena Diniz Gilaberte; Zerfass, Geise de Santana dos Anjos; Shimabukuro, Seirin; Nóbrega, Marcos, II

    2017-12-01

    An international research cruise named Iatá-Piuna took place on the São Paulo Plateau on May 2013 in the Campos and Espírito Santo basins, off Brazil. The cruise was carried ou on board the research vessel (R/V) Yokosuka that hosts the human operated vehicle (HOV) SHINKAI 6500. It aimed at finding chemosynthetic communities, composed of organisms capable of generating their own vital energy by metabolizing organic and inorganic compounds related to seeps. Identification of these organisms could provide information for understanding the origin of life, since they may resemble primitive organisms that existed in the initial stages of life on Earth. During Leg 2 (May 10-24, 2013), however, dives on the northern part of the São Paulo Plateau at the Espírito Santo Basin led to the discovery of a giant oil seep. The seep, ca. 3 nautical miles (ca. 5.6 km) in length is located along an outcrop of Eocene rocks on a salt-induced escarpment of the plateau and at a water depth of ca. 2700 m. The 200 m relief of the seafloor suggests that the seep takes place along an active fault system driven by salt diapirism. The oil was analyzed and identified as a severely biodegraded marine oil, generated by carbonate rocks within a minibasin located to the east of the escarpment. This represents valuable exploratory information because it proves that an active petroleum system is present in the context of minibasins associated with salt diapirism in the area.

  18. The role of an evolving porosity in fluid-rock interaction - a synthesis of insights gained in six years of in-situ 4D microtomography experiments

    Science.gov (United States)

    Fusseis, Florian

    2017-04-01

    Effective fluid rock interaction relies on permeable pore space for fluid to move in. In dynamic (tectono-)metamorphic environments, pore space will be transient and subject to continuous modification. As a consequence, transport properties of rocks evolve throughout their metamorphic history, which complicates the interpretation of fossilised traces of fluid-rock interaction in natural rock samples. Thankfully, a large body of processes involved in fluid-rock interaction occur on time scales accessible in experiments, and over the past decades significant insights were gained in many now classical laboratory investigations. Until recently though, fluid-rock interaction could not be observed directly, and processes and rates were inferred through indirect measurements or post-mortem analyses. Studies that utilise x-rays or neutrons to continuously image fluid-mediated processes inside experimental vessels allow, on the one hand, to quantify their rates but also to assess and characterise transient porosity on the grain scale. In this presentation, I will synthesize the findings from several collaborative experimental studies that documented and quantified fluid-rock interaction in 4-dimensional x-ray microtomographic datasets. Most of these experiments were conducted in bespoke x-ray transparent vessels built in Edinburgh and all of them involved a dynamically evolving porosity as a key element of the studied processes. The latter are 1) the dehydration of gypsum single crystals and alabaster, 2) the carbonation of olivine aggregates, 3) pressure solution in polycrystalline salt, and 4) the dolomitisation of various carbonates. The microtomographic time series data enabled the direct observation of the above processes on the grain scale and were used to quantify their advance using sophisticated image analytical workflows. Each of the studies characterised porosity formation or alteration by a particular mechanism relevant to geological scenarios and it became

  19. Radiological characterisation - Know your objective

    International Nuclear Information System (INIS)

    Lindow, Veronica; Moeller, Jennifer

    2012-01-01

    When developing a programme for mapping the radiological characteristics of a facility to be decommissioned it is important to take into account the objectives of the programme. Will the results be used to plan for radiological control and selection of appropriate decontamination and dismantling techniques? Will the radiological inventory be used for dimensioning of future waste repositories? These are two examples of the applications for such studies, which could require that a radiological characterisation programme be adapted to provide the data appropriate to the intended use. The level of detail and scope needed for a radiological characterisation will also vary depending on how the data will be used. An application to free-release a facility requires a comprehensive survey and well documented analysis in order to ensure that no radioactive contamination above prescribed levels is present. A bounding calculation to determine the maximum anticipated volumes and activity of radioactive waste requires a different approach. During the past few years, older decommissioning studies for the Swedish nuclear power plants have been updated (or are in the process of being updated). The decommissioning study's main purpose is to estimate the cost for decommissioning. The cost estimation is based on material and activity inventories, which in turn is based on previous and, in some cases, updated radiological characterisations of the facilities. The radiological inventory is an important part of the study as it affects the cost of decommissioning but also the uncertainties and accuracy of the cost estimation. The presentation will discuss the challenges in specifying a radiological characterisation programme with multiple objectives, together with insights on how data delivered can be applied to yield results suitable for the intended purpose, without introducing excessive conservatism. The intent of the presentation is to define issues that can be of use in various aspects

  20. Provenance and tectonic setting of the Neoproterozoic clastic rocks hosting the Banana Zone Cu-Ag mineralisation, northwest Botswana

    Science.gov (United States)

    Kelepile, Tebogo; Bineli Betsi, Thierry; Franchi, Fulvio; Shemang, Elisha; Suh, Cheo Emmanuel

    2017-05-01

    Petrographic and geochemical data were combined in order to decipher the petrogenesis of the Neoproterozoic sedimentary succession associated with the Banana Zone Cu-Ag mineralisation (northwest Botswana), in the Kalahari Copperbelt. The investigated Neoproterozoic sedimentary succession is composed of two formations including the Ngwako Pan and the D'kar Formations. The Ngwako Pan Formation is made up of continental siliciclastic sediments, mainly sandstones interbedded with siltstones and mudstones, whereas the D'kar Formation is comprised of shallow marine laminated siltstones, sandstones and mudstones, with subordinate limestone. Copper-Ag mineralisation is essentially confined at the base of the D'kar Formation, which bears reduced organic components, likely to have controlled Cu-Ag precipitation. Sandstones of both the Ngwako Pan and the D'kar Formations are arkoses and subarkoses, composed of quartz (Q), feldspars (F) and lithic fragments (L). Moreover, geochemically the sandstones are considered as potassic and classified as arkoses. On the other hand, mudrocks of the D'kar Formation are finely laminated and are dominated by muscovite, sericite, chlorite and quartz. The modified chemical index of weathering (CIW‧) values indicated an intense chemical weathering of the source rock. The dominance of detrital quartz and feldspar grains coupled with Al2O3/TiO2 ratios (average 29.67 and 24.52 for Ngwako Pan and D'kar Formations, respectively) and Ni and Cr depletion in the sandstones, suggest a dominant felsic source. However, high concentrations of Ni and Cr and a low Al2O3/TiO2 ratio (block and deposited in a continental rift setting (passive margin) in a humid environment. The source rocks might have been the Palaeoproterozoic basement rocks (granitoids and granitic gneiss) and the Mesoproterozoic Kgwebe volcanic rocks exposed north of the study area.

  1. Effect of endocytosis inhibitors on Coxiella burnetii interaction with host cells

    International Nuclear Information System (INIS)

    Tujulin, E.; Macellaro, A.; Norlander, L.; Liliehoeoek, B.

    1998-01-01

    The obligate intracellular rickettsia Coxiella burnetii has previously been reported to reach the intra-vacuolar compartment of host cells by phagocytosis. With the aim to further examine the mechanisms of C. burnetii internalisation, macrophage monolayers were treated with well characterised inhibitors of endocytosis. The treatment with two general inhibitors, colchicine and methylamine, resulted in a pronounced dose-dependent decrease of radiolabelled phase II rickettsiae retained from the intracellular fraction. A third inhibitor used, amiloride, has been reported to reduce effectively clathrin-independent pinocytic pathways. The internalisation of C. burnetii was shown to be substantially reduced also by amiloride and the effect was dependent on its concentration. The passive role of C. burnetii in the internalisation was verified by using heat-killed C. burnetii. Host cells treated with either of the three inhibitors (amiloride, colchicine and methylamine) showed a similar reduction of intracellular C. burnetii after exposure to killed as weal as live organisms. The data presented indicate that different endocytic mechanisms, pinocytosis as well as phagocytosis, may mediate the uptake of C. burnetii by a host cell. Key words: Coxiella burnetii; internalisation; endocytosis (authors)

  2. Delayed colonisation of Acacia by thrips and the timing of host-conservatism and behavioural specialisation.

    Science.gov (United States)

    McLeish, Michael J; Miller, Joseph T; Mound, Laurence A

    2013-09-09

    Repeated colonisation of novel host-plants is believed to be an essential component of the evolutionary success of phytophagous insects. The relative timing between the origin of an insect lineage and the plant clade they eat or reproduce on is important for understanding how host-range expansion can lead to resource specialisation and speciation. Path and stepping-stone sampling are used in a Bayesian approach to test divergence timing between the origin of Acacia and colonisation by thrips. The evolution of host-plant conservatism and ecological specialisation is discussed. Results indicated very strong support for a model describing the origin of the common ancestor of Acacia thrips subsequent to that of Acacia. A current estimate puts the origin of Acacia at approximately 6 million years before the common ancestor of Acacia thrips, and 15 million years before the origin of a gall-inducing clade. The evolution of host conservatism and resource specialisation resulted in a phylogenetically under-dispersed pattern of host-use by several thrips lineages. Thrips colonised a diversity of Acacia species over a protracted period as Australia experienced aridification. Host conservatism evolved on phenotypically and environmentally suitable host lineages. Ecological specialisation resulted from habitat selection and selection on thrips behavior that promoted primary and secondary host associations. These findings suggest that delayed and repeated colonisation is characterised by cycles of oligo- or poly-phagy. This results in a cumulation of lineages that each evolve host conservatism on different and potentially transient host-related traits, and facilitates both ecological and resource specialisation.

  3. Implementation of the full-scale emplacement (FE) experiment at the Mont Terri rock laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Müller, H.R.; Garitte, B.; Vogt, T.; and others

    2017-04-15

    Opalinus Clay is currently being assessed as the host rock for a deep geological repository for high-level and low- and intermediate-level radioactive wastes in Switzerland. Within this framework, the 'Full-Scale Emplacement' (FE) experiment was initiated at the Mont Terri rock laboratory close to the small town of St-Ursanne in Switzerland. The FE experiment simulates, as realistically as possible, the construction, waste emplacement, backfilling and early post-closure evolution of a spent fuel/vitrified high-level waste disposal tunnel according to the Swiss repository concept. The main aim of this multiple heater test is the investigation of repository-induced thermo-hydro-mechanical (THM) coupled effects on the host rock at this scale and the validation of existing coupled THM models. For this, several hundred sensors were installed in the rock, the tunnel lining, the bentonite buffer, the heaters and the plug. This paper is structured according to the implementation timeline of the FE experiment. It documents relevant details about the instrumentation, the tunnel construction, the production of the bentonite blocks and the highly compacted 'granulated bentonite mixture' (GBM), the development and construction of the prototype 'backfilling machine' (BFM) and its testing for horizontal GBM emplacement. Finally, the plug construction and the start of all 3 heaters (with a thermal output of 1350 Watt each) in February 2015 are briefly described. In this paper, measurement results representative of the different experimental steps are also presented. Tunnel construction aspects are discussed on the basis of tunnel wall displacements, permeability testing and relative humidity measurements around the tunnel. GBM densities achieved with the BFM in the different off-site mock-up tests and, finally, in the FE tunnel are presented. Finally, in situ thermal conductivity and temperature measurements recorded during the first heating months

  4. The Usability of Rock-Like Materials for Numerical Studies on Rocks

    Science.gov (United States)

    Zengin, Enes; Abiddin Erguler, Zeynal

    2017-04-01

    The approaches of synthetic rock material and mass are widely used by many researchers for understanding the failure behavior of different rocks. In order to model the failure behavior of rock material, researchers take advantageous of different techniques and software. But, the majority of all these instruments are based on distinct element method (DEM). For modeling the failure behavior of rocks, and so to create a fundamental synthetic rock material model, it is required to perform related laboratory experiments for providing strength parameters. In modelling studies, model calibration processes are performed by using parameters of intact rocks such as porosity, grain size, modulus of elasticity and Poisson ratio. In some cases, it can be difficult or even impossible to acquire representative rock samples for laboratory experiments from heavily jointed rock masses and vuggy rocks. Considering this limitation, in this study, it was aimed to investigate the applicability of rock-like material (e.g. concrete) to understand and model the failure behavior of rock materials having complex inherent structures. For this purpose, concrete samples having a mixture of %65 cement dust and %35 water were utilized. Accordingly, intact concrete samples representing rocks were prepared in laboratory conditions and their physical properties such as porosity, pore size and density etc. were determined. In addition, to acquire the mechanical parameters of concrete samples, uniaxial compressive strength (UCS) tests were also performed by simultaneously measuring strain during testing. The measured physical and mechanical properties of these extracted concrete samples were used to create synthetic material and then uniaxial compressive tests were modeled and performed by using two dimensional discontinuum program known as Particle Flow Code (PFC2D). After modeling studies in PFC2D, approximately similar failure mechanism and testing results were achieved from both experimental and

  5. Rock stress measurements using the LUT-Gauge overcoring method

    International Nuclear Information System (INIS)

    Leijon, B.

    1988-04-01

    With overcoring techniques, rock stresses are determined indirectly from measurements of the dimensional changes of a borehole, occurring when the rock volume surrounding the hole is isolated from the stresses in the host rock. This thesis describes the development and application of an overcoring technique. The key-component of the instrumentation that has been developed is a triaxial borehole strain cell, referred to as the LUT-Gauge. Laboratory tests were conducted to evaluate the performance of the instrumentation. Special emphasis was given to determining temperature sensitivity of the measuring system since this was identified as a potential source of measurement error. Results indicated good instrument reliability and that the measurement error due to temperature variations typically experienced under field conditions is ± 1 MPa or less. The technique was also evaluated by a series of field tests. Comparison of the results obtained by the different methods showed satisfactory agreement. Analysis of the comprehensive field data collected showed that the confidence that can be attached to an overcoring test is largely governed by the mechanical characteristics of the overcored specimen. Expressed as the standard deviation of the mean stress magnitude, the scatter obtained from repeated testing within a borehole section of about 10 m in length, is found to be ± 4 MPa or less. Rock engineering investigations typically refer to a scale of hundreds of metres or more. This study has demonstrated the existence of significant variations of the stress field on this scale. These variations thus impose difficulties in the application of stress data to the analysis of problems in rock engineering, since the pointwise results obtained from stress measurements cannot be extrapolated with good confidence. (30 refs.) (author)

  6. What requirements does the KBS-3 repository make on the host rock? Geoscientific suitability indicators and criteria for siting and site evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Johan [Golder Grundteknik AB (Sweden); Stroem, Anders; Svemar, Christer [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Almen, Karl-Erik [KEA Geo-Konsult AB, Naessjoe (Sweden); Ericsson, Lars O. [Chalmers University of Technology, Goeteborg (Sweden)

    2000-04-01

    This report gives an account of what requirements are made on the rock, what conditions in the rock are advantageous and how the fulfilment of requirements and preferences is to be judged prior to the selection of sites for a site investigation and during a site investigation. The conclusions and results of the report are based on the knowledge and experience acquired by SKB over many years of research and development. The results, and particularly the stipulated criteria, apply to a repository for spent fuel of the KBS-3 type, i.e. a repository where the fuel is contained in copper canisters embedded in bentonite clay at a depth of 400 - 700 m in the Swedish crystalline basement. The report analyzes how the rock's different geological conditions, mechanical, thermal, hydrogeological, chemical and transport properties influence the functions of the deep repository, and whether it is possible to determine requirements and preferences regarding the influence of these properties. Where possible, these requirements or preferences have then been translated into requirements or preferences regarding the individual properties. Criteria are formulated that are based on the quantities that can be measured or estimated at the relevant stage of the investigation. The following requirements are made on the rock: The rock in the repository's deposition zone may not have any ore potential. Regional plastic shear zones shall be avoided if it cannot be demonstrated that the properties of the zone do not deviate from those of the rest of the rock. There may, however, be so-called 'tectonic lenses' near regional plastic shear zones where the bedrock is homogeneous and relatively unaffected. Deposition tunnels and deposition holes for canisters may not pass through or be positioned too close to major regional and major local fracture zones. Deposition holes may not intersect identified local minor fracture zones. The rock's strength, fracture geometry and

  7. Use of variations in unit cell length, reflectance and hardness for determining the origin of Fe disulphides in sedimentary rocks

    Science.gov (United States)

    Dill, H. G.; Eberhard, E.; Hartmann, B.

    1997-01-01

    Fe disulphides are common opaque accessories in sedimentary rocks. Both marcasite and pyrite may shed some light on the depositional environment and help determine the diagenesis of their host rocks. Quantitative ore microscopy (reflectance measurements, Vickers hardness numbers) and X-ray diffraction methods, supplemented with scanning electron microscopy and chemical analyses, were applied to pyrite (and some marcasite) hosted by sedimentary rocks spanning the interval from the Devonian to the Pliocene, and formed in various marine and continental environments. Quantitative ore microscopy of pyrites of sedimentary origin does not seem to be an efficient tool for analyzing the environment owing to the inhomogeneous nature of sulphide aggregates when viewed under the ore microscope, and the variable amounts of minor elements (e.g., As, Ni, and Co) that control the reflectance values (RV) and Vickers hardness numbers (VHN) of the host sulphides. However, such parameters as crystal habit and unit cell length of pyrite, which correlate with FeS x, are useful for environmental analysis. The redox conditions and the presence of organic remains during formation are the main factors determining these crystallographic parameters. Differences in these parameters from those of pure, ideal FeS 2 can be related to substitution of, e.g., wustite in the pyrite lattice, reflecting moderate oxidation (i.e. in the microenvironment). As far as crystal habit and length of the cell edge are concerned, late stage diagenesis is obviously less important than the microenvironment attending initial formation. The environment of deposition (i.e. the macroenvironment) of pyrite-bearing rocks has no influence on the crystal morphology or the length of the unit cell of Fe disulphide. X-ray diffraction measurements demonstrate that this method provides useful evidence on the microenvironment of sulphide precipitation around a single, equant pyrite, as well as around pyritized fossils.

  8. Rock stars for the day

    CERN Multimedia

    Stefania Pandolfi

    2015-01-01

    After a two-year hiatus, the CERN Hardronic Festival is back! On 8 August, ten CERN MusiClub bands will take to the stage for the popular event. As usual, the non-stop show will take place on the terrace of Restaurant 3 and will run until after midnight.   The Canettes Blues Band, part of the CERN MusiClub, performing live on the Music In The Park stage at the Montreux Jazz Festival, on 18 July 2013. A large range of musical styles will entertain the audience: from Irish folk, via 70s/80s/90s rock, to pop, blues and R&B. Alongside the music there will be activities for kids and food and drink stands. This year, the income from food sales will be donated to charity. The spirit that has characterised the festival ever since the first event in 1989 is that of a staff party. Any band who volunteers to play also helps to organise the event and set up the stage. “This is a really good thing because a festival that has been growing for many years requires a considerable amount of har...

  9. Early trace of life from 3.95 Ga sedimentary rocks in Labrador, Canada.

    Science.gov (United States)

    Tashiro, Takayuki; Ishida, Akizumi; Hori, Masako; Igisu, Motoko; Koike, Mizuho; Méjean, Pauline; Takahata, Naoto; Sano, Yuji; Komiya, Tsuyoshi

    2017-09-27

    The vestiges of life in Eoarchean rocks have the potential to elucidate the origin of life. However, gathering evidence from many terrains is not always possible, and biogenic graphite has thus far been found only in the 3.7-3.8 Ga (gigayears ago) Isua supracrustal belt. Here we present the total organic carbon contents and carbon isotope values of graphite (δ 13 C org ) and carbonate (δ 13 C carb ) in the oldest metasedimentary rocks from northern Labrador. Some pelitic rocks have low δ 13 C org values of -28.2, comparable to the lowest value in younger rocks. The consistency between crystallization temperatures of the graphite and metamorphic temperature of the host rocks establishes that the graphite does not originate from later contamination. A clear correlation between the δ 13 C org values and metamorphic grade indicates that variations in the δ 13 C org values are due to metamorphism, and that the pre-metamorphic value was lower than the minimum value. We concluded that the large fractionation between the δ 13 C carb and δ 13 C org values, up to 25‰, indicates the oldest evidence of organisms greater than 3.95 Ga. The discovery of the biogenic graphite enables geochemical study of the biogenic materials themselves, and will provide insight into early life not only on Earth but also on other planets.

  10. Characterisation of Tmmmian Local Sorghmn Varieties

    African Journals Online (AJOL)

    Many local varieties of sorghum grown in Tanzania have not been characterised in terms of their end uses. This study was conducted to characterise 14 such varieties. Three improved varieties commonly grown in this country were includedfor comparison. Physical analyses that included 100-grain weight, percent dehulling ...

  11. Rock Art

    Science.gov (United States)

    Henn, Cynthia A.

    2004-01-01

    There are many interpretations for the symbols that are seen in rock art, but no decoding key has ever been discovered. This article describes one classroom's experiences with a lesson on rock art--making their rock art and developing their own personal symbols. This lesson allowed for creativity, while giving an opportunity for integration…

  12. SiteChar. Characterisation of European CO2 storage. Deliverable D8.1. Qualitative and quantitative social site characterisations

    Energy Technology Data Exchange (ETDEWEB)

    Brunsting, S.; Pol, M.; Paukovic, M. [ECN Policy Studies, Energy research Centre of the Netherlands ECN, Amsterdam (Netherlands); Kaiser, M.; Zimmer, R. [Unabhaengiges Institut fuer Umweltfragen UfU, Berlin (Germany); Shackley, S.; Mabon, L. [Scottish Carbon Capture and Storage SCCS, Edinburg, Scotland (United Kingdom); Hepplewhite, F.; Loveridge, R. [Energy Markets Unit, Scottish Government, Edinburg, Scotland (United Kingdom); Mazurowski, M.; Polak-Osiniak, D. [Polish Oil and Gas Company PGNiG, Warszawa (Poland); Rybicki, C. [AGH University of Science and Technology, Krakow (Poland)

    2012-10-15

    At local level, public support has proven crucial to the implementation of CO2 capture and storage (CCS) demonstration projects. Whereas no method exists to guarantee public acceptability of any project, a constructive stakeholder engagement process does increase the likelihood thereof. Social site characterisation can be used as an instrument to explore, plan and evaluate a process of active and constructive local stakeholder engagement in a prospective CCS project as a parallel activity to technical site characterisation. It roughly consists of a formative research phase to get acquainted with the area followed by a series of public information and engagement activities. This deliverable presents results from the first phase for the social site characterisations of a prospective CCS site in Poland (onshore) and the UK (offshore), using qualitative as well as quantitative research methods, as a first step to planning of local public engagement activities and evaluation of these activities that will be undertaken by this consortium at both sites in the near future. Although the term social site characterisation actually refers to the entire process of formative research and subsequent public outreach, and hence to the complete package of awareness work undertaken as part of SiteChar, in the present deliverable the term only refers to the formative research activities as undertaken up to now and as described in this deliverable. The qualitative part of the social site characterisation consisted of (1) a description of relevant social site characteristics such as local history; (2) interviews with relevant local stakeholders; (3) a media analysis of local newspapers. The quantitative part of the social site characterisation consisted of surveys using representative samples to characterise the local population in terms of awareness, knowledge and perceptions of CCS, felt involvement in decision making, extent of local activism, level of trust in representatives and

  13. 1{sup st} workshop proceedings of the collaborative project ''Crystalline rock retention processes'' (7th EC FP CP CROCK)

    Energy Technology Data Exchange (ETDEWEB)

    Rabung, Thomas; Molinero, Jorge; Garcia, David; Montoya, Vanessa (eds.)

    2012-07-01

    The EURATOM 7th EC Framework Program Collaborative Project Crystalline ROCK retention processes (CROCK) started in January 2011 and extends over 2 and a half years. The key driver for initiation the CP CROCK, identified by national Waste Management Organizations, is the undesired high uncertainty and the associated conservatism with respect to the radionuclide transport in the crystalline host-rock far-field around geological disposal of high-level radioactive wastes.

  14. Characterisation of NORM Contaminated Objects: Reliable and Efficient

    DEFF Research Database (Denmark)

    Breddam, Kresten; Hou, Xiaolin; Koufakis, Markos

    The predominant contributors to the production of Technologically En-hanced Naturally Occurring Radioactive Material (TENORM) and NORM-waste in the Nordic countries are the on- and offshore oil and gas produc-ers. In oil and gas production processes, host rock formation water con-taining low...... concentrations of NORM is mixed with seawater containing high concentrations of sulphate. This leads to precipitation of NORM (Ra, Pb, Po)SO4, which is deposited as either scale or sludge in the production equipment. NORM contaminated pipes, tubes, pumps and tanks, etc. are therefore subject to radiological...... characterization in order to ensure safe reuse or recycling as well as safe NORM waste handling.The procedures and measurement techniques may significantly affect the amount of mate-rial that is categorized as NORM contaminated equipment and NORM waste. At present, different procedures are used for categorization...

  15. Identification of igneous rocks in a superimposed basin through integrated interpretation dominantly based on magnetic data

    Science.gov (United States)

    LI, S.

    2017-12-01

    Identification of igneous rocks in the basin environment is of great significance to the exploration for hydrocarbon reservoirs hosted in igneous rocks. Magnetic methods are often used to alleviate the difficulties faced by seismic imaging in basins with thick cover and complicated superimposed structures. We present a case study on identification of igneous rocks in a superimposed basin through integrated interpretation based on magnetic and other geophysical data sets. The study area is located in the deepest depression with sedimentary cover of 14,000 m in Huanghua basin, which is a Cenozoic basin superimposed on a residual pre-Cenozoic basin above the North China craton. Cenozoic and Mesozoic igneous rocks that are dominantly intermediate-basic volcanic and intrusive rocks are widespread at depth in the basin. Drilling and seismic data reveal some volcanic units and intrusive rocks in Cenozoic stratum at depths of about 4,000 m. The question remains to identify the lateral extent of igneous rocks in large depth and adjacent areas. In order to tackle the difficulties for interpretation of magnetic data arisen from weak magnetic anomaly and remanent magnetization of igneous rocks buried deep in the superimposed basin, we use the preferential continuation approach to extract the anomaly and magnetic amplitude inversion to image the 3D magnetic units. The resultant distribution of effective susceptibility not only correlates well with the locations of Cenozoic igneous rocks known previously through drilling and seismic imaging, but also identifies the larger scale distribution of Mesozoic igneous rocks at greater depth in the west of the basin. The integrated interpretation results dominantly based on magnetic data shows that the above strategy is effective for identification of igneous rocks deep buried in the superimposed basin. Keywords: Identification of igneous rocks; Superimposed basin; Magnetic data

  16. Geoelectrical characterisation of basement aquifers: the case of Iberekodo, southwestern Nigeria

    Science.gov (United States)

    Aizebeokhai, Ahzegbobor P.; Oyeyemi, Kehinde D.

    2018-03-01

    Basement aquifers, which occur within the weathered and fractured zones of crystalline bedrocks, are important groundwater resources in tropical and subtropical regions. The development of basement aquifers is complex owing to their high spatial variability. Geophysical techniques are used to obtain information about the hydrologic characteristics of the weathered and fractured zones of the crystalline basement rocks, which relates to the occurrence of groundwater in the zones. The spatial distributions of these hydrologic characteristics are then used to map the spatial variability of the basement aquifers. Thus, knowledge of the spatial variability of basement aquifers is useful in siting wells and boreholes for optimal and perennial yield. Geoelectrical resistivity is one of the most widely used geophysical methods for assessing the spatial variability of the weathered and fractured zones in groundwater exploration efforts in basement complex terrains. The presented study focuses on combining vertical electrical sounding with two-dimensional (2D) geoelectrical resistivity imaging to characterise the weathered and fractured zones in a crystalline basement complex terrain in southwestern Nigeria. The basement aquifer was delineated, and the nature, extent and spatial variability of the delineated basement aquifer were assessed based on the spatial variability of the weathered and fractured zones. The study shows that a multiple-gradient array for 2D resistivity imaging is sensitive to vertical and near-surface stratigraphic features, which have hydrological implications. The integration of resistivity sounding with 2D geoelectrical resistivity imaging is efficient and enhances near-surface characterisation in basement complex terrain.

  17. Seismic-Scale Rock Physics of Methane Hydrate

    Energy Technology Data Exchange (ETDEWEB)

    Amos Nur

    2009-01-08

    We quantify natural methane hydrate reservoirs by generating synthetic seismic traces and comparing them to real seismic data: if the synthetic matches the observed data, then the reservoir properties and conditions used in synthetic modeling might be the same as the actual, in-situ reservoir conditions. This approach is model-based: it uses rock physics equations that link the porosity and mineralogy of the host sediment, pressure, and hydrate saturation, and the resulting elastic-wave velocity and density. One result of such seismic forward modeling is a catalogue of seismic reflections of methane hydrate which can serve as a field guide to hydrate identification from real seismic data. We verify this approach using field data from known hydrate deposits.

  18. Best Practice on facility characterisation from a material and waste end-state perspective. Radiological characterisation in a waste and materials end-state perspective - International Characterisation Survey Aiming to Understand Good Practice

    International Nuclear Information System (INIS)

    Larsson, Arne; Weber, Inge; Emptage, Matthew; )

    2016-01-01

    Full text of publication follows: The Task Group on Radiological Characterisation and Decommissioning within the Nuclear Energy Agency (NEA) Working Party on Decommissioning was established to identify and present Best Practice in radiological characterisation at different stages of decommissioning as well as areas that could or should be developed further by international cooperation and coordination. The first phase of the project was focusing on general aspects of strategies for radiological characterisation in decommissioning of nuclear facilities. The second phase of the project focus on strategies for optimising radiological characterisation in a waste and materials end-state perspective, building on previous task group findings. One of the activities within the second phase has been to conduct a survey with the main objective to identify Best Practice. The survey was in the form of a questionnaire in two versions, one for regulators and one for owners/implementers. Sections of the questionnaire to gather views on Best Practice: - Initiation of a characterisation program; - Planning and preparation; - Implementation (i.e. conducting the characterisation measurements and samplings); - Data assessment phase (evaluation of the results); - Quality assurance. A section on the national legislation in the regulator version and a case study section in the owner version complement the questionnaire in order to get an overview of the regulatory frameworks and also practical experiences. The extensive questionnaire was distributed to a wide audience of recognised experts throughout the member states. 53 responses were received from in total 12 countries. Most responses were from Europe but also Asia and North America were represented. The preliminary conclusions are: - There is a solid experience in radiological characterisation among regulators as well as owners/implementers; - Responses demonstrates to large extent a common view of regulators and owners

  19. Modelling of salt water upconing in Olkiluoto

    International Nuclear Information System (INIS)

    Loefman, J.; Poteri, A.; Pitkaenen, P.

    2010-04-01

    Posiva Oy is preparing for the final disposal of spent nuclear fuel in the crystalline bedrock in Finland. Olkiluoto in Eurajoki has been selected as the primary site for the repository, subject to further detailed characterisation, which is currently focused on the construction of an underground rock characterisation and research facility (the ONKALO). During the repository operation the open tunnels and shafts of the ONKALO, and the subsequent repository, are likely to create a hydraulic disturbance to the site's groundwater system for hundreds of years (the greatest impact concerns only the time of the operational period, i.e., c. 100 years). In particular, during the operational phase of the repository upward flow below the tunnels may give rise to the upconing of deep highly saline groundwater up to the planned repository rock volume, which is a concern with regard to the performance of the tunnel backfill material after the closure of the tunnels. This study concerns the supporting groundwater flow analysis for the Rock Suitability Criteria (RSC) programme, which has been set up to develop host rock requirements for the repository design and layout adaptation. The objective is to assess the potential upconing of deep highly saline groundwater into the planned repository rock volume. The work is divided into three separate sub-tasks: characterization of the expected upconing on the basis of 1) observations in the drillholes, 2) numerical groundwater flow modelling, and 3) the analytic groundwater flow modelling

  20. Mapping local singularities using magnetic data to investigate the volcanic rocks of the Qikou depression, Dagang oilfield, eastern China

    Directory of Open Access Journals (Sweden)

    G. Chen

    2013-07-01

    Full Text Available The spatial structural characteristics of geological anomaly, including singularity and self-similarity, can be analysed using fractal or multifractal modelling. Here we apply the multifractal methods to potential fields to demonstrate that singularities can characterise geological bodies, including rock density and magnetic susceptibility. In addition to enhancing weak gravity and magnetic anomalies with respect to either strong or weak background levels, the local singularity index (α ≈ 2 can be used to delineate the edges of geological bodies. Two models were established to evaluate the effectiveness of mapping singularities for extracting weak anomalies and delineating edges of buried geological bodies. The Qikou depression of the Dagang oilfield in eastern China has been chosen as a study area for demonstrating the extraction of weak anomalies of volcanic rocks, using the singularity mapping technique to analyse complex magnetic anomalies caused by complex geological background. The results have shown that the singularities of magnetic data mapped in the paper are associated with buried volcanic rocks, which have been verified by both drilling and seismic survey, and the S–N and E–W faults in the region. The targets delineated for deeply seated faults and volcanic rocks in the Qikou depression should be further investigated for the potential application in undiscovered oil and gas reservoirs exploration.

  1. U-Pb, Re-Os, and Ar/Ar geochronology of rare earth element (REE)-rich breccia pipes and associated host rocks from the Mesoproterozoic Pea Ridge Fe-REE-Au deposit, St. Francois Mountains, Missouri

    Science.gov (United States)

    Aleinikoff, John N.; Selby, David; Slack, John F.; Day, Warren C.; Pillers, Renee M.; Cosca, Michael A.; Seeger, Cheryl; Fanning, C. Mark; Samson, Iain

    2016-01-01

    Rare earth element (REE)-rich breccia pipes (600,000 t @ 12% rare earth oxides) are preserved along the margins of the 136-million metric ton (Mt) Pea Ridge magnetite-apatite deposit, within Mesoproterozoic (~1.47 Ga) volcanic-plutonic rocks of the St. Francois Mountains terrane in southeastern Missouri, United States. The breccia pipes cut the rhyolite-hosted magnetite deposit and contain clasts of nearly all local bedrock and mineralized lithologies.Grains of monazite and xenotime were extracted from breccia pipe samples for SHRIMP U-Pb geochronology; both minerals were also dated in one polished thin section. Monazite forms two morphologies: (1) matrix granular grains composed of numerous small (minerals includes Re-Os on fine-grained molybdenite and 40Ar/39Ar on muscovite, biotite, and K-feldspar.Ages (±2σ errors) obtained by SHRIMP U-Pb analysis are as follows: (1) zircon from the two host rhyolite samples have ages of 1473.6 ± 8.0 and 1472.7 ± 5.6 Ma; most zircon in late felsic dikes is interpreted as xenocrystic (age range ca. 1522–1455 Ma); a population of rare spongy zircon is likely of igneous origin and yields an age of 1441 ± 9 Ma; (2) pale-yellow granular monazite—1464.9 ± 3.3 Ma (no dated xenotime); (3) reddish matrix granular monazite—1462.0 ± 3.5 Ma and associated xenotime—1453 ± 11 Ma; (4) coarse glassy-yellow monazite—1464.8 ± 2.1, 1461.7 ± 3.7 Ma, with rims at 1447.2 ± 4.7 Ma; and (5) matrix monazite (in situ)—1464.1 ± 3.6 and 1454.6 ± 9.6 Ma, and matrix xenotime (in situ)—1468.0 ± 8.0 Ma. Two slightly older ages of cores are about 1478 Ma. The young age of rims on the coarse glassy monazite coincides with an Re-Os age of 1440.6 ± 9.2 Ma determined in this study for molybdenite intergrown with quartz and allanite, and with the age of monazite inclusions in apatite from the magnetite ore (Neymark et al., 2016). A 40Ar/39Ar age of 1473 ± 1 Ma was obtained for muscovite from a breccia pipe sample.Geochronology and

  2. Thermally induced rock stress increment and rock reinforcement response

    International Nuclear Information System (INIS)

    Hakala, M.; Stroem, J.; Nujiten, G.; Uotinen, L.; Siren, T.; Suikkanen, J.

    2014-07-01

    This report describes a detailed study of the effect of thermal heating by the spent nuclear fuel containers on the in situ rock stress, any potential rock failure, and associated rock reinforcement strategies for the Olkiluoto underground repository. The modelling approach and input data are presented together repository layout diagrams. The numerical codes used to establish the effects of heating on the in situ stress field are outlined, together with the rock mass parameters, in situ stress values, radiogenic temperatures and reinforcement structures. This is followed by a study of the temperature and stress evolution during the repository's operational period and the effect of the heating on the reinforcement structures. It is found that, during excavation, the maximum principal stress is concentrated at the transition areas where the profile changes and that, due to the heating from the deposition of spent nuclear fuel, the maximum principal stress rises significantly in the tunnel arch area of NW/SW oriented central tunnels. However, it is predicted that the rock's crack damage (CD, short term strength) value of 99 MPa will not be exceeded anywhere within the model. Loads onto the reinforcement structures will come from damaged and loosened rock which is assumed in the modelling as a free rock wedge - but this is very much a worst case scenario because there is no guarantee that rock cracking would form a free rock block. The structural capacity of the reinforcement structures is described and it is predicted that the current quantity of the rock reinforcement is strong enough to provide a stable tunnel opening during the peak of the long term stress state, with damage predicted on the sprayed concrete liner. However, the long term stability and safety can be improved through the implementation of the principles of the Observational Method. The effect of ventilation is also considered and an additional study of the radiogenic heating effect on the brittle

  3. Thermally induced rock stress increment and rock reinforcement response

    Energy Technology Data Exchange (ETDEWEB)

    Hakala, M. [KMS Hakala Oy, Nokia (Finland); Stroem, J.; Nujiten, G.; Uotinen, L. [Rockplan, Helsinki (Finland); Siren, T.; Suikkanen, J.

    2014-07-15

    This report describes a detailed study of the effect of thermal heating by the spent nuclear fuel containers on the in situ rock stress, any potential rock failure, and associated rock reinforcement strategies for the Olkiluoto underground repository. The modelling approach and input data are presented together repository layout diagrams. The numerical codes used to establish the effects of heating on the in situ stress field are outlined, together with the rock mass parameters, in situ stress values, radiogenic temperatures and reinforcement structures. This is followed by a study of the temperature and stress evolution during the repository's operational period and the effect of the heating on the reinforcement structures. It is found that, during excavation, the maximum principal stress is concentrated at the transition areas where the profile changes and that, due to the heating from the deposition of spent nuclear fuel, the maximum principal stress rises significantly in the tunnel arch area of NW/SW oriented central tunnels. However, it is predicted that the rock's crack damage (CD, short term strength) value of 99 MPa will not be exceeded anywhere within the model. Loads onto the reinforcement structures will come from damaged and loosened rock which is assumed in the modelling as a free rock wedge - but this is very much a worst case scenario because there is no guarantee that rock cracking would form a free rock block. The structural capacity of the reinforcement structures is described and it is predicted that the current quantity of the rock reinforcement is strong enough to provide a stable tunnel opening during the peak of the long term stress state, with damage predicted on the sprayed concrete liner. However, the long term stability and safety can be improved through the implementation of the principles of the Observational Method. The effect of ventilation is also considered and an additional study of the radiogenic heating effect on the

  4. Iodine and selenium migration through argillaceous rocks

    International Nuclear Information System (INIS)

    Frasca, Benjamin

    2011-01-01

    Deep argillaceous formations are considered as potential host rock for high-level radioactive waste repository. Based on safety assessment calculations, active selenium ( 79 Se) and iodine ( 129 I) from high level radioactive waste might be ones of the major dose contributors due to their longevity and their anionic character. However, because of their high sensitivity to redox condition, a special attention to the oxidation state of these elements is required. A comparative study on the diffusion properties of selenium and iodine through argillaceous rocks was realized with the aim to determine the effects of both the redox conditions and the mineralogy on the migration of these two elements. For these purposes, we have studied two argillaceous rocks: Toarcian argillite from Tournemire (France) and Opalinus clay (OPA) from the Mont-Terri (Switzerland). The study of the iodide migration allowed to confirm the control on the iodide retention of both oxidized pyrite and natural organic matter. A kinetic control of the iodide sorption is also suspected. We focus the selenium study on the more oxidized species, Se(IV) and Se(VI). The Se(IV) migration is strongly dependant from oxido-reduction processes. Indeed, the Se(IV) diffusion experiments through Tournemire argillite and OPA indicated a significant reduction associated to Fe(II). The Se(VI) study evidenced a behavior dependant from the initial concentration: at the highest concentration, no significant retention was observed while the retention is significant at the lowest concentration. Furthermore, spectroscopic analyses tend to show a low Se(VI) reduction at the Fe contact. However, biotic origin cannot be excluded. (author)

  5. Comparison of disposal concepts for rock salt and hard rock

    International Nuclear Information System (INIS)

    Papp, R.

    1998-01-01

    The study was carried out in the period 1994-1996. The goals were to prepare a draft on spent fuel disposal in hard rock and additionally a comparison with existing disposal concepts for rock salt. A cask for direct disposal of spent fuel and a repository for hard rock including a safeguards concept were conceptually designed. The results of the study confirm, that the early German decision to employ rock salt was reasonable. (orig.)

  6. What requirements does the KBS-3 repository make on the host rock? Geoscientific suitability indicators and criteria for siting and site evaluation

    International Nuclear Information System (INIS)

    Andersson, Johan; Stroem, Anders; Svemar, Christer; Almen, Karl-Erik; Ericsson, Lars O.

    2000-04-01

    This report gives an account of what requirements are made on the rock, what conditions in the rock are advantageous and how the fulfilment of requirements and preferences is to be judged prior to the selection of sites for a site investigation and during a site investigation. The conclusions and results of the report are based on the knowledge and experience acquired by SKB over many years of research and development. The results, and particularly the stipulated criteria, apply to a repository for spent fuel of the KBS-3 type, i.e. a repository where the fuel is contained in copper canisters embedded in bentonite clay at a depth of 400 - 700 m in the Swedish crystalline basement. The report analyzes how the rock's different geological conditions, mechanical, thermal, hydrogeological, chemical and transport properties influence the functions of the deep repository, and whether it is possible to determine requirements and preferences regarding the influence of these properties. Where possible, these requirements or preferences have then been translated into requirements or preferences regarding the individual properties. Criteria are formulated that are based on the quantities that can be measured or estimated at the relevant stage of the investigation. The following requirements are made on the rock: The rock in the repository's deposition zone may not have any ore potential. Regional plastic shear zones shall be avoided if it cannot be demonstrated that the properties of the zone do not deviate from those of the rest of the rock. There may, however, be so-called 'tectonic lenses' near regional plastic shear zones where the bedrock is homogeneous and relatively unaffected. Deposition tunnels and deposition holes for canisters may not pass through or be positioned too close to major regional and major local fracture zones. Deposition holes may not intersect identified local minor fracture zones. The rock's strength, fracture geometry and initial stresses may not be

  7. Mechanism of Rock Burst Occurrence in Specially Thick Coal Seam with Rock Parting

    Science.gov (United States)

    Wang, Jian-chao; Jiang, Fu-xing; Meng, Xiang-jun; Wang, Xu-you; Zhu, Si-tao; Feng, Yu

    2016-05-01

    Specially thick coal seam with complex construction, such as rock parting and alternative soft and hard coal, is called specially thick coal seam with rock parting (STCSRP), which easily leads to rock burst during mining. Based on the stress distribution of rock parting zone, this study investigated the mechanism, engineering discriminant conditions, prevention methods, and risk evaluation method of rock burst occurrence in STCSRP through setting up a mechanical model. The main conclusions of this study are as follows. (1) When the mining face moves closer to the rock parting zone, the original non-uniform stress of the rock parting zone and the advancing stress of the mining face are combined to intensify gradually the shearing action of coal near the mining face. When the shearing action reaches a certain degree, rock burst easily occurs near the mining face. (2) Rock burst occurrence in STCSRP is positively associated with mining depth, advancing stress concentration factor of the mining face, thickness of rock parting, bursting liability of coal, thickness ratio of rock parting to coal seam, and difference of elastic modulus between rock parting and coal, whereas negatively associated with shear strength. (3) Technologies of large-diameter drilling, coal seam water injection, and deep hole blasting can reduce advancing stress concentration factor, thickness of rock parting, and difference of elastic modulus between rock parting and coal to lower the risk of rock burst in STCSRP. (4) The research result was applied to evaluate and control the risk of rock burst occurrence in STCSRP.

  8. Rollerjaw Rock Crusher

    Science.gov (United States)

    Peters, Gregory; Brown, Kyle; Fuerstenau, Stephen

    2009-01-01

    The rollerjaw rock crusher melds the concepts of jaw crushing and roll crushing long employed in the mining and rock-crushing industries. Rollerjaw rock crushers have been proposed for inclusion in geological exploration missions on Mars, where they would be used to pulverize rock samples into powders in the tens of micrometer particle size range required for analysis by scientific instruments.

  9. Range sections as rock models for intensity rock scene segmentation

    CSIR Research Space (South Africa)

    Mkwelo, S

    2007-11-01

    Full Text Available This paper presents another approach to segmenting a scene of rocks on a conveyor belt for the purposes of measuring rock size. Rock size estimation instruments are used to monitor, optimize and control milling and crushing in the mining industry...

  10. Rock sealing - large scale field test and accessory investigations

    International Nuclear Information System (INIS)

    Pusch, R.

    1988-03-01

    The experience from the pilot field test and the basic knowledge extracted from the lab experiments have formed the basis of the planning of a Large Scale Field Test. The intention is to find out how the 'instrument of rock sealing' can be applied to a number of practical cases, where cutting-off and redirection of groundwater flow in repositories are called for. Five field subtests, which are integrated mutually or with other Stripa projects (3D), are proposed. One of them concerns 'near-field' sealing, i.e. sealing of tunnel floors hosting deposition holes, while two involve sealing of 'disturbed' rock around tunnels. The fourth concerns sealing of a natural fracture zone in the 3D area, and this latter test has the expected spin-off effect of obtaining additional information on the general flow pattern around the northeastern wing of the 3D cross. The fifth test is an option of sealing structures in the Validation Drift. The longevity of major grout types is focussed on as the most important part of the 'Accessory Investigations', and detailed plans have been worked out for that purpose. It is foreseen that the continuation of the project, as outlined in this report, will yield suitable methods and grouts for effective and long-lasting sealing of rock for use at stategic points in repositories. (author)

  11. Host age modulates within-host parasite competition.

    Science.gov (United States)

    Izhar, Rony; Routtu, Jarkko; Ben-Ami, Frida

    2015-05-01

    In many host populations, one of the most striking differences among hosts is their age. While parasite prevalence differences in relation to host age are well known, little is known on how host age impacts ecological and evolutionary dynamics of diseases. Using two clones of the water flea Daphnia magna and two clones of its bacterial parasite Pasteuria ramosa, we examined how host age at exposure influences within-host parasite competition and virulence. We found that multiply-exposed hosts were more susceptible to infection and suffered higher mortality than singly-exposed hosts. Hosts oldest at exposure were least often infected and vice versa. Furthermore, we found that in young multiply-exposed hosts competition was weak, allowing coexistence and transmission of both parasite clones, whereas in older multiply-exposed hosts competitive exclusion was observed. Thus, age-dependent parasite exposure and host demography (age structure) could together play an important role in mediating parasite evolution. At the individual level, our results demonstrate a previously unnoticed interaction of the host's immune system with host age, suggesting that the specificity of immune function changes as hosts mature. Therefore, evolutionary models of parasite virulence might benefit from incorporating age-dependent epidemiological parameters. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  12. Developing two-phase flow modelling concepts for rock fractures

    Energy Technology Data Exchange (ETDEWEB)

    Keto, V. (Fortum Nuclear Services Oy, Espoo (Finland))

    2010-01-15

    The Finnish nuclear waste disposal company, Posiva Oy, is planning an underground repository for spent nuclear fuel to be constructed on the island of Olkiluoto on the south-west coast of Finland. One element of the site investigations conducted at Olkiluoto is the excavation of the underground rock characterisation facility (ONKALO) that will be extended to the final disposal depth (approximately -400 m). The bedrock around the excavated tunnel volume is fully saturated with groundwater, which water commonly contains a mixture of dissolved gases. These gases remain dissolved due to the high hydrostatic pressure. During tunnel excavation work the natural hydrostatic pressure field is disturbed and the water pressure will decrease close to the atmospheric pressure in the immediate vicinity of the tunnel. During this pressure drop two-phase flow conditions (combined flow of both water and gas) may develop in the vicinity of the underground opening, as the dissolved gas is exsoluted under the low pressure (the term exsolution refers here to release of the dissolved gas molecules from the water phase into a separate gas phase). This report steers towards concept development for numerical two-phase flow modeling for fractured rock. The focus is on the description of gas phase formation process under disturbed hydraulic conditions by exsolution of dissolved gases from groundwater, and on understanding the effects of a possibly formed gas phase on groundwater flow conditions in rock fractures. A mathematical model of three mutually coupled nonlinear partial differential equations for two-phase flow is presented and corresponding constitutional relationships are introduced and discussed. Illustrative numerical simulations are performed in a simplified setting using COMSOL Multiphysics 3.5a - software package. Shortcomings and conceptual problems are discussed. (orig.)

  13. Developing two-phase flow modelling concepts for rock fractures

    International Nuclear Information System (INIS)

    Keto, V.

    2010-01-01

    The Finnish nuclear waste disposal company, Posiva Oy, is planning an underground repository for spent nuclear fuel to be constructed on the island of Olkiluoto on the south-west coast of Finland. One element of the site investigations conducted at Olkiluoto is the excavation of the underground rock characterisation facility (ONKALO) that will be extended to the final disposal depth (approximately -400 m). The bedrock around the excavated tunnel volume is fully saturated with groundwater, which water commonly contains a mixture of dissolved gases. These gases remain dissolved due to the high hydrostatic pressure. During tunnel excavation work the natural hydrostatic pressure field is disturbed and the water pressure will decrease close to the atmospheric pressure in the immediate vicinity of the tunnel. During this pressure drop two-phase flow conditions (combined flow of both water and gas) may develop in the vicinity of the underground opening, as the dissolved gas is exsoluted under the low pressure (the term exsolution refers here to release of the dissolved gas molecules from the water phase into a separate gas phase). This report steers towards concept development for numerical two-phase flow modeling for fractured rock. The focus is on the description of gas phase formation process under disturbed hydraulic conditions by exsolution of dissolved gases from groundwater, and on understanding the effects of a possibly formed gas phase on groundwater flow conditions in rock fractures. A mathematical model of three mutually coupled nonlinear partial differential equations for two-phase flow is presented and corresponding constitutional relationships are introduced and discussed. Illustrative numerical simulations are performed in a simplified setting using COMSOL Multiphysics 3.5a - software package. Shortcomings and conceptual problems are discussed. (orig.)

  14. Rock deformation in hydrothermal systems: the nature of fractures in plutons and their host rocks. Technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    Norton, D.

    1981-11-01

    The purpose of this program is to accumulate the types of field data which are important for the analysis of magma-hydrothermal systems. The structural effects of thermal processes were identified in order to distinguish the thermally induced deformations from the deformations that occurred subsequent to complete cooling of the system. Mapping techniques were developed to record the structural data on the ground from local domains characteristic of larger areas in the magma chamber, and in the air from low-angle oblique aerial photography of the entire region. The ground system is complete and preliminary testing is currently being carried out to verify the method. The results indicate that granitic crystalline rocks have no structural resistance to thermal perturbations. If nuclear wastes are to be stored in granite, precautionary buffers would have to be incorporated into the system. A total of 30 fossil magma chambers have been studied over the past 2 years. An extensive set of fracture imagery has been collected, together with information related to the geological history of the plutons. Fossil magma chambers in Arizona, Utah, California, Washington, Montana, and British Columbia have been studied.

  15. Groundwater/porewater hydrochemistry at Horonobe URL. Data freeze 1. Preliminary data quality evaluation for boreholes HDB-9, 10 and 11

    International Nuclear Information System (INIS)

    Kunimaru, Takanori; Ota, Kunio; Alexander, W. Russell; Yamamoto, Hajime

    2010-11-01

    Characterisation of the geological environment within host sedimentary formations is currently ongoing at the site of the Horonobe Underground Research Laboratory in northern Hokkaido, Japan, with the main aim of establishing and testing the relevant techniques for future repository site characterisation. One facet of this is one of the first use of rock matrix porewater data in Japan, in conjunction with the site groundwater data, as part of characterisation of the site hydrochemistry. Surface-based investigations have been largely completed and one of the remaining issues is the development of an appropriate quality assurance (QA) system which is applicable to all aspects of the site characterisation process. A QA audit of hydrochemical datasets for boreholes HDB-9 - 11 has been carried out by the application of a formal QA analysis which is based on the methodology previously employed for groundwaters during the recent site characterisation programme in Sweden. To set this novel approach specifically for rock matrix porewater data in context, several guidelines for assigning the QA categories of the porewater data are proposed. Discussion on the quality level of both the groundwater and porewater data is presented as is a preliminary description of the site hydrochemistry. This exercise has indicated areas where additional information would be of value and further improvement of work would be required to the ongoing hydrochemical characterisation at Horonobe. Overall, it is emphasised that an appropriate QA system, which is among the first such tools required for repository site characterisation, will save on effort by reducing errors and the requirement to re-sample and re-analysis - but this can only be guaranteed by continuously assessing if the system is truly fit-for-purpose and amending it as necessary based on the practical experience of the end-users on-site. (author)

  16. Characterisation of semiconductor materials for ionising radiation detectors

    International Nuclear Information System (INIS)

    Vaitkus, J.; Gaubas, E.; Jasinskaite, R.; Juska, G.; Kazukauskas, V.; Puras, R.; Rahman, M.; Sakalauskas, S.; Smith, K.

    2002-01-01

    Methods for the detection and characterisation of semiconductor material parameters and inhomogeneities are analysed. The peculiarities of different 'classical' material and structure characterisation methods are discussed. The methods of lifetime and surface recombination mapping and electric field distribution in the samples are presented. Some results of investigations of GaAs, Si and SiC are used for the characterisation of different peculiarities or methods

  17. Disposal of radioactive waste in Swedish crystalline rocks

    International Nuclear Information System (INIS)

    Greis Dahlberg, Christina; Wikberg, Peter

    2015-01-01

    SKB, Swedish Nuclear Fuel and Waste Management Company is tasked with managing Swedish nuclear and radioactive waste. Crystalline rock is the obvious alternative for deep geological disposal in Sweden. SKB is, since 1988, operating a near surface repository for short-lived low and intermediate-level waste, SFR. The waste in SFR comprises operational and decommissioning waste from nuclear plants, industrial waste, research-related waste and medical waste. Spent nuclear fuel is currently stored in an interim facility while waiting for a license to construct a deep geological repository. The Swedish long-lived low and intermediate-level waste consists mainly of BWR control rods, reactor internals and legacy waste from early research in the Swedish nuclear programs. The current plan is to dispose of this waste in a separate deep geological repository, SFL, sometimes after 2045. Understanding of the rock properties is the basis for the design of the repository concepts. Swedish crystalline rock is mechanical stable and suitable for underground constructions. The Spent Fuel Repository is planned at approximately 500 meters depth in the rock at the Forsmark site. The host rock will keep the spent fuel isolated from human and near-surface environment. The rock will also provide the stable chemical and hydraulic conditions that make it possible to select suitable technical barriers to support the containment provided by the rock. A very long lasting canister is necessary to avoid release and transport of radionuclides through water conducting fractures in the rock. A canister designed for the Swedish rock, consists of a tight, 5 cm thick corrosion barrier of copper and a load-bearing insert of cast iron. To restrict the water flow around the canister and by that prevent fast corrosion, a bentonite buffer will surround the canister. Secondary, the bentonite buffer will retard a potential release by its strong sorption of radionuclides. The SFR repository is situated in

  18. Disposal of radioactive waste in Swedish crystalline rocks

    Energy Technology Data Exchange (ETDEWEB)

    Greis Dahlberg, Christina; Wikberg, Peter [Svensk Kaernbraenslehantering AB, Stockholm (Sweden)

    2015-07-01

    SKB, Swedish Nuclear Fuel and Waste Management Company is tasked with managing Swedish nuclear and radioactive waste. Crystalline rock is the obvious alternative for deep geological disposal in Sweden. SKB is, since 1988, operating a near surface repository for short-lived low and intermediate-level waste, SFR. The waste in SFR comprises operational and decommissioning waste from nuclear plants, industrial waste, research-related waste and medical waste. Spent nuclear fuel is currently stored in an interim facility while waiting for a license to construct a deep geological repository. The Swedish long-lived low and intermediate-level waste consists mainly of BWR control rods, reactor internals and legacy waste from early research in the Swedish nuclear programs. The current plan is to dispose of this waste in a separate deep geological repository, SFL, sometimes after 2045. Understanding of the rock properties is the basis for the design of the repository concepts. Swedish crystalline rock is mechanical stable and suitable for underground constructions. The Spent Fuel Repository is planned at approximately 500 meters depth in the rock at the Forsmark site. The host rock will keep the spent fuel isolated from human and near-surface environment. The rock will also provide the stable chemical and hydraulic conditions that make it possible to select suitable technical barriers to support the containment provided by the rock. A very long lasting canister is necessary to avoid release and transport of radionuclides through water conducting fractures in the rock. A canister designed for the Swedish rock, consists of a tight, 5 cm thick corrosion barrier of copper and a load-bearing insert of cast iron. To restrict the water flow around the canister and by that prevent fast corrosion, a bentonite buffer will surround the canister. Secondary, the bentonite buffer will retard a potential release by its strong sorption of radionuclides. The SFR repository is situated in

  19. Aespoe Hard Rock Laboratory. Annual report 1998

    International Nuclear Information System (INIS)

    1999-05-01

    instrumented. Characterisation of the rock mass in the area of the Prototype repository in progress. The Backfill and Plug Test includes tests of backfill materials and emplacement methods and a test of a full-scale plug. The backfill and rock will be instrumented with about 230 transducers for measuring the thermo-hydro-mechanical processes. The Retrieval Test is aiming at demonstrating the readiness for recovering of emplaced canisters also after the time when the bentonite has swollen. Planning and preparations for these experiments has continued during 1998. The Long Term Tests of Buffer Material aim to validate models of buffer performance at standard KBS-3 repository conditions, and at quantifying clay buffer alteration processes at adverse conditions. Two test holes were instrumented late 1996 and the temperature was raised to 90 and 130 deg C, respectively. The test parcels have now been retrieved and analysed. All tests and analyses except those concerning microstructure have been completed. No unexpected results have been obtained. Ten organisations from nine countries are currently participating in the Aespoe Hard Rock Laboratory in addition to SKB

  20. Aespoe Hard Rock Laboratory. Annual report 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-05-01

    instrumented. Characterisation of the rock mass in the area of the Prototype repository in progress. The Backfill and Plug Test includes tests of backfill materials and emplacement methods and a test of a full-scale plug. The backfill and rock will be instrumented with about 230 transducers for measuring the thermo-hydro-mechanical processes. The Retrieval Test is aiming at demonstrating the readiness for recovering of emplaced canisters also after the time when the bentonite has swollen. Planning and preparations for these experiments has continued during 1998. The Long Term Tests of Buffer Material aim to validate models of buffer performance at standard KBS-3 repository conditions, and at quantifying clay buffer alteration processes at adverse conditions. Two test holes were instrumented late 1996 and the temperature was raised to 90 and 130 deg C, respectively. The test parcels have now been retrieved and analysed. All tests and analyses except those concerning microstructure have been completed. No unexpected results have been obtained. Ten organisations from nine countries are currently participating in the Aespoe Hard Rock Laboratory in addition to SKB.

  1. Matrix diffusion of simple cations, anions, and neutral species in fractured crystalline rocks

    International Nuclear Information System (INIS)

    Sato, Haruo

    1999-01-01

    The diffusion of radionuclides into the pore spaces of a rock matrix and the pore properties in fractured crystalline rocks were studied. The work concentrated on the predominant water-conducting fracture system in the host granodiorite of the Kamaishi In Situ Test Site, which consists of fracture fillings and altered grandodiorite. Through-diffusion experiments to obtain effective and apparent diffusion coefficients (De and Da, respectively) for Na + , Cs + , HTO, Cl - , and SeO 3 2- as a function of ionic charge were conducted through the fracture fillings and altered and intact granodiorite. The total porosity φ, density, pore-size distribution, and specific surface area of the pores of the rocks were also determined by a water saturation method and Hg porosimetry. The average φ is, in the order from highest to lowest, as follows: fracture fillings (5.6%) greater than altered granodiorite (3.2%) greater than intact granodiorite (2.3%), and gradually it decreases into the matrix. The pore sizes of the intact and altered granodiorite range from 10 nm to 200 microm, and the fracture fillings from 50 nm to 200 microm, but almost all pores are found around 0.1 and 200 microm in the fracture fillings. The De values for all species are in the following order: fracture fillings greater than altered granodiorite greater than intact granodiorite, as with the rock porosity. In addition. no effect of ionic charge on De is found. No significant dependence for Da values on the rock porosity is found. The formation factors FF and geometric factors G of the rocks were evaluated by normalizing the free water diffusion coefficient Do for each species. The FF decreased with decreasing rock porosity, and an empirical equation for the rock porosity was derived to be FF = φ 1.57±0.02 . The G values showed a tendency to slightly decrease with decreasing rock porosity, but they were approximately constant (0.12 to 0.19) in this porosity range. This indicates that accessible pores

  2. Genesis and transport of hexavalent chromium in the system ophiolitic rocks - groundwater

    Science.gov (United States)

    Shchegolikhina, Anastasia; Guadagnini, Laura; Guadagnini, Alberto

    2015-04-01

    Our study aims at contributing to the quantification and characterization of chromium transport processes from host rocks and soil matrices to groundwater. We focus on dissolved hexavalent chromium detected in groundwaters of geological regions with ophiolitic rocks (ophiolites and serpentinites) inclusions due to its critical ecological impact. (Oze et al., 2004). Despite the large number of analyses on the occurrence of high concentrations of hazardous hexavalent chromium ions in natural waters, only few studies were performed with the objective of identifying and investigating the geochemical reactions which could occur in the natural system rock - groundwater - dissolved chromium (Fantoni et al., 2002, Stephen and James, 2004, Lelli et al., 2013). In this context, there is a need for integration of results obtained from diverse studies in various regions and settings to improve our knowledge repository. Our theoretical analyses are grounded and driven by practical scenarios detected in subsurface reservoirs exploited for civil and industrial use located in the Emilia-Romagna region (Italy). Available experimental datasets are complemented with data from other international regional-scale settings (Altay mountains region, Russia). Modeling of chromium transformation and migration particularly includes characterization of the multispecies geochemical system. A key aspect of our study is the analysis of the complex competitive sorption processes governing heavy metal evolution in groundwater. The results of the research allow assessing the critical qualitative features of the mechanisms of hexavalent chromium ion mobilization from host rocks and soils and the ensuing transformation and migration to groundwater under the influence of diverse environmental factors. The study is then complemented by the quantification of the main sources of uncertainty associated with prediction of heavy metal contamination levels in the groundwater system explored. Fantoni, D

  3. Occurrence, hosts, morphology, and molecular characterisation of Pasteuria bacteria parasitic in nematodes of the family Plectidae.

    Science.gov (United States)

    Sturhan, Dieter; Shutova, Tatyana S; Akimov, Vladimir N; Subbotin, Sergei A

    2005-01-01

    Parasitic bacteria of the genus Pasteuria are reported for three Anaplectus and four identified and several unidentified Plectus species found in eight countries in various habitats. The pasteurias from plectids agree in essential morphological characters of sporangia and endospores as well as in developmental cycle with those of the Pasteuria species and strains described from tylenchid nematodes, but appear to be mainly distinguished from these by absence of a distinct perisporium in the spores and the endospores obviously not being cup- or saucer-shaped. The wide range of measurements and morphological peculiarities of sporangia and endospores suggest that probably several Pasteuria species have to be distinguished as parasites in Plectidae. From an infected juvenile of an unidentified plectid species the 16S rRNA gene sequence of Pasteuria sp. was obtained. Substantial sequence divergence from described Pasteuria species and its phylogenetic position on molecular trees indicate that this Pasteuria sp. could be considered as a new species. Preliminary results of the analysis of DNA phylogeny of Pasteuria spp. and their nematode hosts provide evidence for incongruence of their phylogenetic history and of host switching events during evolution of the bacterial parasites.

  4. Ecological characterisation of the Colombian entomopathogenic nematode Heterorhabditis sp. SL0708.

    Science.gov (United States)

    Mejia-Torres, M C; Sáenz, A

    2013-05-01

    The entomopathogenic nematode Heterorhabditis sp. SL0708 (Rhabditida: Heterorhabditidae) isolated from soil in Alcalá, Valle del Cauca (Colombia) was characterised ecologically using Galleria mellonella larvae (L) (Pyralidae: Galleriinae) as hosts. The effect of temperature on the viability, infectivity and reproduction, and of moisture on infectivity and storage in liquid were evaluated in infective juveniles (IJs). Significant differences were found in the viability, infectivity and reproduction of the IJs at different temperatures. No nematodes were recovered at 5 °C and 10 °C, and at 35 °C no infectivity was observed. Average daily nematode recovery was best at 25 °C, and survival of the IJs was low in substrates presenting 13% moisture. The optimal storage temperature for Heterorhabditis sp. SL0708 was between 20 °C and 30 °C, keeping its infectivity for up to 8 weeks.

  5. Sediment-hosted gold deposits of the world: database and grade and tonnage models

    Science.gov (United States)

    Berger, Vladimir I.; Mosier, Dan L.; Bliss, James D.; Moring, Barry C.

    2014-01-01

    All sediment-hosted gold deposits (as a single population) share one characteristic—they all have disseminated micron-sized invisible gold in sedimentary rocks. Sediment-hosted gold deposits are recognized in the Great Basin province of the western United States and in China along with a few recognized deposits in Indonesia, Iran, and Malaysia. Three new grade and tonnage models for sediment-hosted gold deposits are presented in this paper: (1) a general sediment-hosted gold type model, (2) a Carlin subtype model, and (3) a Chinese subtype model. These models are based on grade and tonnage data from a database compilation of 118 sediment-hosted gold deposits including a total of 123 global deposits. The new general grade and tonnage model for sediment-hosted gold deposits (n=118) has a median tonnage of 5.7 million metric tonnes (Mt) and a gold grade of 2.9 grams per tonne (g/t). This new grade and tonnage model is remarkable in that the estimated parameters of the resulting grade and tonnage distributions are comparable to the previous model of Mosier and others (1992). A notable change is in the reporting of silver in more than 10 percent of deposits; moreover, the previous model had not considered deposits in China. From this general grade and tonnage model, two significantly different subtypes of sediment-hosted gold deposits are differentiated: Carlin and Chinese. The Carlin subtype includes 88 deposits in the western United States, Indonesia, Iran, and Malaysia, with median tonnage and grade of 7.1 Mt and 2.0 g/t Au, respectively. The silver grade is 0.78 g/t Ag for the 10th percentile of deposits. The Chinese subtype represents 30 deposits in China, with a median tonnage of 3.9 Mt and medium grade of 4.6 g/t Au. Important differences are recognized in the mineralogy and alteration of the two sediment-hosted gold subtypes such as: increased sulfide minerals in the Chinese subtype and decalcification alteration dominant in the Carlin type. We therefore

  6. Geochemical tracing and hydrogeochemical modelling of water-rock interactions during salinization of alluvial groundwater (Upper Rhine Valley, France)

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, Y., E-mail: yann.lucas@eost.u-strasbg.fr [Universite de Strasbourg et CNRS, Laboratoire d' Hydrologie et de Geochimie de Strasbourg, Ecole et Observatoire des Sciences de la Terre, 1, rue Blessig, 67084 Strasbourg Cedex (France); Schmitt, A.D., E-mail: anne-desiree.schmitt@univ-fcomte.fr [Universite de Strasbourg et CNRS, Laboratoire d' Hydrologie et de Geochimie de Strasbourg, Ecole et Observatoire des Sciences de la Terre, 1, rue Blessig, 67084 Strasbourg Cedex (France)] [Universite de Franche-Comte et CNRS-UMR 6249, Chrono-Environnement, 16, Route de Gray, 25030 Besancon Cedex (France); Chabaux, F., E-mail: francois.chabaux@eost.u-strasbg.fr [Universite de Strasbourg et CNRS, Laboratoire d' Hydrologie et de Geochimie de Strasbourg, Ecole et Observatoire des Sciences de la Terre, 1, rue Blessig, 67084 Strasbourg Cedex (France); Clement, A.; Fritz, B. [Universite de Strasbourg et CNRS, Laboratoire d' Hydrologie et de Geochimie de Strasbourg, Ecole et Observatoire des Sciences de la Terre, 1, rue Blessig, 67084 Strasbourg Cedex (France); Elsass, Ph. [BRGM, GEODERIS, 1, rue Claude Chappe, 57070 Metz (France); Durand, S. [Universite de Strasbourg et CNRS, Laboratoire d' Hydrologie et de Geochimie de Strasbourg, Ecole et Observatoire des Sciences de la Terre, 1, rue Blessig, 67084 Strasbourg Cedex (France)

    2010-11-15

    Research highlights: {yields} Major and trace elements along with strontium and uranium isotopic ratios show that groundwater geochemical characteristics along the saline plumes cannot reflect a conservative mixing. {yields} A coupled hydrogeochemical model demonstrates that cationic exchange between alkalis from polluted waters and alkaline-earth elements from montmorillonite present in the host rock of the aquifer is the primary process. {yields} The model requires only a small amount of montmorillonite. {yields} It is necessary to consider the pollution history to explain the important chloride, sodium and calcium concentration modifications. {yields} The model shows that the rapidity of the cationic exchange reactions insures a reversibility of the cation fixation on clays in the aquifer. - Abstract: In the southern Upper Rhine Valley, groundwater has undergone intensive saline pollution caused by the infiltration of mining brines, a consequence of potash extraction carried out during the 20th century. Major and trace elements along with Sr and U isotopic ratios show that groundwater geochemical characteristics along the saline plumes cannot reflect conservative mixing between saline waters resulting from the dissolution of waste heaps and one or more unpolluted end-members. The results imply the occurrence of interactions between host rocks and polluted waters, and they suggest that cationic exchange mechanisms are the primary controlling process. A coupled hydrogeochemical model has been developed with the numerical code KIRMAT, which demonstrates that cationic exchange between alkalis from polluted waters and alkaline-earth elements from montmorillonite present in the host rock of the aquifer is the primary process controlling the geochemical evolution of the groundwater. The model requires only a small amount of montmorillonite (between 0.75% and 2.25%), which is in agreement with the observed mineralogical composition of the aquifer. The model also proves

  7. Rock geochemistry related to mineralization processes in geothermal areas

    Science.gov (United States)

    Kausar, A. Al; Indarto, S.; Setiawan, I.

    2018-02-01

    Abundant geothermal systems in Indonesia suggest high heat and mass transfer associated with recent or paleovolcanic arcs. In the active geothermal system, the upflow of mixed fluid between late stage hydrothermal and meteoric water might contain mass of minerals associated with epithermal mineralisation process as exemplified at Lihir gold mine in Papua New Guinea. In Indonesia, there is a lack of study related to the precious metals occurrence within active geothermal area. Therefore, in this paper, we investigate the possibility of mineralization process in active geothermal area of Guci, Central Java by using geochemical analysis. There are a lot of conducted geochemical analysis of water, soil and gas by mapping the temperature, pH, Hg and CO2 distribution, and estimating subsurface temperature based on geothermometry approach. Then we also apply rock geochemistry to find minerals that indicate the presence of mineralization. The result from selected geothermal area shows the presence of pyrite and chalcopyrite minerals on the laharic breccias at Kali Putih, Sudikampir. Mineralization is formed within host rock and the veins are associated with gold polymetallic mineralization.

  8. R20 programme: Development of rock grouting design, techniques and procedures for ONKALO

    International Nuclear Information System (INIS)

    Sievaenen, U.

    2009-02-01

    Posiva Oy constructs an underground research facility ONKALO at Olkiluoto in Eurajoki. ONKALO is planned to be a part of the deep repository for the high level nuclear waste. Posiva Oy set up R20-programme for the years 2006-2008, with the target of having an acceptable grouting methodology in ONKALO. The programme was divided into three projects and the work and results of Technique-project is presented in this report. The implementation of the results (grouting design and execution) was outlined from the project. That work is under the responsibility of construction of the ONKALO-project. The Grouting Technique -project (INKE) studied the grouting experiences obtained from the first 2 km of the ONKALO access tunnel, searched for suitable grouting design approaches, carried out two grouting tests and one pilot grouting test with colloidal silica in ONKALO, analysed the expected grouting conditions in deep rock from the grouting point of view, studied the feasibility of so called optimal design solution in the expected grouting conditions. Based on these studies recommendations concerning the grouting design, design solutions for different rock conditions, grouting procedures, grouting stop criteria, the characterisation methods for grouting purposes, grouting materials and grouting work performance are presented. Swedish Time Stop Grouting, also named Grouting Time-Method was selected to be studied and used in this project and it was further developed. This work compiles the outcome of the project subtasks and presents the recommendations for developing the grouting in ONKALO. The key conclusion of this work are: (1) Grouting Time-method (time stop grouting) alone is not enough to be used as a grouting stop criterion due to the uncertainties related to the source parameters (fracture characteristics, rheological properties of grouts); these cause too high uncertainties when proving the sealing result via the grouting time, (2) due to the uncertainties related to

  9. Characterisation of candidate buffer materials. Vol. 2: Thermo-mechanical calculation of buffer in granitic environment

    International Nuclear Information System (INIS)

    Broc, D.

    1987-01-01

    Mechanical stresses of compacted clays between the canister and the host rock are studied in the different cases during evolution of a vitrified waste storage site. Thermal stress variations are studied in function of time and thermal power decrease of stored wastes and of materials characteristics and behavior. Consequences of stresses produced by partial hydratation of clays are evaluated. The study concludes that an argillaceous containment does not present a rupture risk, even during a partial hydratation in addition stresses on stored packaging are obtained

  10. Fluid and rock interaction in permeable volcanic rock

    International Nuclear Information System (INIS)

    Lindley, J.I.

    1985-01-01

    Four types of interrelated changes -geochemical, mineralogic, isotopic, and physical - occur in Oligocene volcanic units of the Mogollon-Datil volcanic field, New Mexico. These changes resulted from the operation of a geothermal system that, through fluid-rock interaction, affected 5 rhyolite ash-flow tuffs and an intercalated basaltic andesite lava flow causing a potassium metasomatism type of alteration. (1) Previous studies have shown enrichment of rocks in K 2 O as much as 130% of their original values at the expense of Na 2 O and CaO with an accompanying increase in Rb and decreases in MgO and Sr. (2) X-ray diffraction results of this study show that phenocrystic plagioclase and groundmass feldspar have been replaced with pure potassium feldspar and quartz in altered rock. Phenocrystic potassium feldspar, biotite, and quartz are unaffected. Pyroxene in basaltic andesite is replaced by iron oxide. (3) delta 18 O increases for rhyolitic units from values of 8-10 permil, typical of unaltered rock, to 13-15 permil, typical of altered rock. Basaltic andesite, however, shows opposite behavior with a delta 18 of 9 permil in unaltered rock and 6 permit in altered. (4) Alteration results in a density decrease. SEM revealed that replacement of plagioclase by fine-grained quartz and potassium feldspar is not a volume for volume replacement. Secondary porosity is created in the volcanics by the chaotic arrangement of secondary crystals

  11. Characterisation of carbonate rocks from near-surface cross-hole and reflection GPR investigations - A case study from southeast Zealand, Denmark

    DEFF Research Database (Denmark)

    Nielsen, Lars; Looms, Majken Caroline; Hansen, Thomas Mejer

    successful in generating well-defined statistical parameters for the GPR velocity field of the subsurface than the typical strategy in which the total rock section covered by the cross-hole data is regarded as the same type of medium. Modelling strategies in which porosity data from the boreholes...

  12. Matrix fluid chemistry experiment. Final report June 1998 - March 2003

    International Nuclear Information System (INIS)

    Smellie, John A.T.; Waber, H. Niklaus; Frape, Shaun K.

    2003-06-01

    The Matrix Fluid Chemistry Experiment set out to determine the composition and evolution of matrix pore fluids/waters in low permeable rock located at repository depths in the Aespoe Hard Rock Laboratory (HRL). Matrix pore fluids/waters can be highly saline in composition and, if accessible, may influence the near-field groundwater chemistry of a repository system. Characterising pore fluids/waters involved in-situ borehole sampling and analysis integrated with laboratory studies and experiments on rock matrix drill core material. Relating the rate of in-situ pore water accumulation during sampling to the measured rock porosity indicated a hydraulic conductivity of 10 -14 -10 -13 m/s for the rock matrix. This was in accordance with earlier estimated predictions. The sampled matrix pore water, brackish in type, mostly represents older palaeo- groundwater mixtures preserved in the rock matrix and dating back to at least the last glaciation. A component of matrix pore 'fluid' is also present. One borehole section suggests a younger groundwater component which has accessed the rock matrix during the experiment. There is little evidence that the salinity of the matrix pore waters has been influenced significantly by fluid inclusion populations hosted by quartz. Crush/leach, cation exchange, pore water diffusion and pore water displacement laboratory experiments were carried out to compare extracted/calculated matrix pore fluids/waters with in-situ sampling. Of these the pore water diffusion experiments appear to be the most promising approach and a recommended site characterisation protocol has been formulated. The main conclusions from the Matrix Fluid Chemistry Experiment are: Groundwater movement within the bedrock hosting the experimental site has been enhanced by increased hydraulic gradients generated by the presence of the tunnel, and to a much lesser extent by the borehole itself. Over experimental timescales ∼4 years) solute transport through the rock matrix

  13. Matrix fluid chemistry experiment. Final report June 1998 - March 2003

    Energy Technology Data Exchange (ETDEWEB)

    Smellie, John A.T. [Conterra AB, Luleaa (Sweden); Waber, H. Niklaus [Univ. of Bern (Switzerland). Inst. of Geology; Frape, Shaun K. [Univ. of Waterloo (Canada). Dept. of Earth Sciences

    2003-06-01

    The Matrix Fluid Chemistry Experiment set out to determine the composition and evolution of matrix pore fluids/waters in low permeable rock located at repository depths in the Aespoe Hard Rock Laboratory (HRL). Matrix pore fluids/waters can be highly saline in composition and, if accessible, may influence the near-field groundwater chemistry of a repository system. Characterising pore fluids/waters involved in-situ borehole sampling and analysis integrated with laboratory studies and experiments on rock matrix drill core material. Relating the rate of in-situ pore water accumulation during sampling to the measured rock porosity indicated a hydraulic conductivity of 10{sup -14}-10{sup -13} m/s for the rock matrix. This was in accordance with earlier estimated predictions. The sampled matrix pore water, brackish in type, mostly represents older palaeo- groundwater mixtures preserved in the rock matrix and dating back to at least the last glaciation. A component of matrix pore 'fluid' is also present. One borehole section suggests a younger groundwater component which has accessed the rock matrix during the experiment. There is little evidence that the salinity of the matrix pore waters has been influenced significantly by fluid inclusion populations hosted by quartz. Crush/leach, cation exchange, pore water diffusion and pore water displacement laboratory experiments were carried out to compare extracted/calculated matrix pore fluids/waters with in-situ sampling. Of these the pore water diffusion experiments appear to be the most promising approach and a recommended site characterisation protocol has been formulated. The main conclusions from the Matrix Fluid Chemistry Experiment are: Groundwater movement within the bedrock hosting the experimental site has been enhanced by increased hydraulic gradients generated by the presence of the tunnel, and to a much lesser extent by the borehole itself. Over experimental timescales {approx}4 years) solute transport

  14. Factors Affecting Diet Variation in the Pyrenean Rock Ptarmigan (Lagopus muta pyrenaica: Conservation Implications.

    Directory of Open Access Journals (Sweden)

    Ricardo García-González

    Full Text Available The Pyrenean rock ptarmigan (Lagopus muta pyrenaica lives at one of the southernmost limits of the ptarmigan range. Their small population sizes and the impacts of global changes are limiting factors in the conservation of this threatened subspecies. An effective conservation policy requires precise basic knowledge of a species' food and habitat requirements, information that is practically non-existent for this Pyrenean population. Here, we describe the diet of a ptarmigan population in the Eastern Pyrenees, the environmental factors influencing its variability and the relationship between diet floristic composition and quality. Diet composition was determined by microhistological analysis of faeces and diet quality was estimated from free-urate faecal N content. Our results show that grouse diet is based mainly on arctic-alpine shrubs of the Ericaceae family, as well as dwarf willows (Salix spp. and Dryas octopetala. The most frequently consumed plant species was Rhododendron ferrugineum, but its abundance in the diet was negatively related to the diet nitrogen content. Conversely, the abundance of Salix spp., grass leaves and arthropods increased the nitrogen content of the diet. Seasonality associated with snow-melting contributed the most to variability in the Pyrenean ptarmigan diet, differentiating winter from spring/summer diets. The latter was characterised by a high consumption of dwarf willows, flowers, arthropods and tender forb leaves. Geographic area and sex-age class influenced diet variability to a lesser extent. Current temperature increases in the Pyrenees due to global warming may reduce the persistence and surface area of snow-packs where preferred plants for rock ptarmigan usually grow, thus reducing food availability. The high consumption of Rh. ferrugineum characterised the diet of the Pyrenean population. Given the toxicity of this plant for most herbivores, its potential negative effect on Pyrenean ptarmigan populations

  15. Origin and evolution of formation water at the Jujo-Tecominoacan oil reservoir, Gulf of Mexico. Part 1: Chemical evolution and water-rock interaction

    Energy Technology Data Exchange (ETDEWEB)

    Birkle, Peter, E-mail: birkle@iie.org.mx [Instituto de Investigaciones Electricas (IIE), Gerencia de Geotermia, Av. Reforma 113, Cuernavaca, Morelos 62490 (Mexico); Garcia, Bernardo Martinez; Milland Padron, Carlos M. [PEMEX Exploracion y Produccion, Region Sur, Activo Integral Bellota-Jujo, Diseno de Explotacion, Cardenas, Tabasco (Mexico)

    2009-04-15

    The origin and evolution of formation water from Upper Jurassic to Upper Cretaceous mudstone-packstone-dolomite host rocks at the Jujo-Tecominoacan oil reservoir, located onshore in SE-Mexico at a depth from 5200 to 6200 m.b.s.l., have been investigated, using detailed water geochemistry from 12 producer wells and six closed wells, and related host rock mineralogy. Saline waters of Cl-Na type with total dissolved solids from 10 to 23 g/L are chemically distinct from hypersaline Cl-Ca-Na and Cl-Na-Ca type waters with TDS between 181 and 385 g/L. Bromine/Cl and Br/Na ratios suggest the subaerial evaporation of seawater beyond halite precipitation to explain the extreme hypersaline components, while less saline samples were formed by mixing of high salinity end members with surface-derived, low salinity water components. The dissolution of evaporites from adjacent salt domes has little impact on present formation water composition. Geochemical simulations with Harvie-M{phi}ller-Weare and PHRQPITZ thermodynamic data sets suggest secondary fluid enrichment in Ca, HCO{sub 3} and Sr by water-rock interaction. The volumetric mass balance between Ca enrichment and Mg depletion confirms dolomitization as the major alteration process. Potassium/Cl ratios below evaporation trajectory are attributed to minor precipitation of K feldspar and illitization without evidence for albitization at the Jujo-Tecominoacan reservoir. The abundance of secondary dolomite, illite and pyrite in drilling cores from reservoir host rock reconfirms the observed water-rock exchange processes. Sulfate concentrations are controlled by anhydrite solubility as indicated by positive SI-values, although anhydrite deposition is limited throughout the lithological reservoir column. The chemical variety of produced water at the Jujo-Tecominoacan oil field is related to a sequence of primary and secondary processes, including infiltration of evaporated seawater and original meteoric fluids, the subsequent

  16. Origin and evolution of formation water at the Jujo-Tecominoacan oil reservoir, Gulf of Mexico. Part 1: Chemical evolution and water-rock interaction

    International Nuclear Information System (INIS)

    Birkle, Peter; Garcia, Bernardo Martinez; Milland Padron, Carlos M.

    2009-01-01

    The origin and evolution of formation water from Upper Jurassic to Upper Cretaceous mudstone-packstone-dolomite host rocks at the Jujo-Tecominoacan oil reservoir, located onshore in SE-Mexico at a depth from 5200 to 6200 m.b.s.l., have been investigated, using detailed water geochemistry from 12 producer wells and six closed wells, and related host rock mineralogy. Saline waters of Cl-Na type with total dissolved solids from 10 to 23 g/L are chemically distinct from hypersaline Cl-Ca-Na and Cl-Na-Ca type waters with TDS between 181 and 385 g/L. Bromine/Cl and Br/Na ratios suggest the subaerial evaporation of seawater beyond halite precipitation to explain the extreme hypersaline components, while less saline samples were formed by mixing of high salinity end members with surface-derived, low salinity water components. The dissolution of evaporites from adjacent salt domes has little impact on present formation water composition. Geochemical simulations with Harvie-Mφller-Weare and PHRQPITZ thermodynamic data sets suggest secondary fluid enrichment in Ca, HCO 3 and Sr by water-rock interaction. The volumetric mass balance between Ca enrichment and Mg depletion confirms dolomitization as the major alteration process. Potassium/Cl ratios below evaporation trajectory are attributed to minor precipitation of K feldspar and illitization without evidence for albitization at the Jujo-Tecominoacan reservoir. The abundance of secondary dolomite, illite and pyrite in drilling cores from reservoir host rock reconfirms the observed water-rock exchange processes. Sulfate concentrations are controlled by anhydrite solubility as indicated by positive SI-values, although anhydrite deposition is limited throughout the lithological reservoir column. The chemical variety of produced water at the Jujo-Tecominoacan oil field is related to a sequence of primary and secondary processes, including infiltration of evaporated seawater and original meteoric fluids, the subsequent mixing of

  17. Effective diffusion coefficients and porosity values for argillaceous rocks and bentonite: measured and estimated values for the provisional safety analyses for SGT-E2

    International Nuclear Information System (INIS)

    Van Loon, L.R.

    2014-11-01

    In Stage 2 of the Sectoral Plan for Deep Geological Repositories, safety analyses have to be performed. Geochemical parameters describing the transport and retardation of radionuclides in the argillaceous rocks considered and in compacted bentonite are required. In the present report, diffusion parameters for all clay host rocks, confining units and compacted bentonite are derived. Diffusion of tritiated water (HTO), "3"6Cl"- and "2"2Na"+ was studied. The measurements gave values for effective diffusion coefficients (D_e) and diffusion accessible porosities. The general observed trend "N"aD_e > "H"T"OD_e > "C"lD_e is in agreement with the expected behaviour of the three species in clay materials: ion exchanging cations show an enhanced mobility due to surface diffusion effects and anions are slowed down due to anion exclusion. Due to the negatively charged clay surfaces, anionic species are repelled from these surfaces resulting in an accessible porosity that is smaller than the total porosity as measured with HTO. The effect of porewater composition on the diffusion of HTO, "3"6Cl"- and "2"2Na"+ in Opalinus Clay was investigated. For ionic strength (IS) values between 0.17 M and 1.07 M, no significant effect on D_e could be observed. In the case of "3"6Cl"-, no effect on the accessible porosity was observed. The anion diffusion accessible porosity equals 50-60 % of the total porosity, independent on the ionic strength of the porewater. The diffusion parameters were measured on sedimentary rocks such as chalk, clay and limestone rocks. All data could be described by one single modified version of Archie's relation (extended Archie's relation). For values of porosity greater than about 0.1, the classical Archie's relation was valid. For values smaller than 0.1, the data deviated from the classical Archie's relation; this can be explained by additional changes of tortuosity with porosity values. At high porosity values (low density rocks), the microfabric of the clay

  18. Geomechanical analysis of excavation-induced rock mass behavior of faulted Opalinus clay at the Mont Terri underground rock laboratory (Switzerland)

    International Nuclear Information System (INIS)

    Thoeny, R.

    2014-01-01

    Clay rock formations are potential host rocks for deep geological disposal of nuclear waste. However, they exhibit relatively low strength and brittle failure behaviour. Construction of underground openings in clay rocks may lead to the formation of an excavation damage zone (EDZ) in the near-field area of the tunnel. This has to be taken into account during risk assessment for waste-disposal facilities. To investigate the geomechanical processes associated with the rock mass response of faulted Opalinus Clay during tunnelling, a full-scale ‘mine-by’ experiment was carried out at the Mont Terri Underground Rock Laboratory (URL) in Switzerland. In the ‘mine-by’ experiment, fracture network characteristics within the experimental section were characterized prior to and after excavation by integrating structural data from geological mapping of the excavation surfaces and from four pre- and post-excavation boreholes.The displacements and deformations in the surrounding rock mass were measured using geo-technical instrumentation including borehole inclinometers, extensometers and deflectometers, together with high-resolution geodetic displacement measurements and laser scanning measurements on the excavation surfaces. Complementary data was gathered from structural and geophysical characterization of the surrounding rock mass. Geological and geophysical techniques were used to analyse the structural and kinematic relationships between the natural and excavation-induced fracture network surrounding the ‘mine-by’ experiment. Integrating the results from seismic refraction tomography, borehole logging, and tunnel surface mapping revealed that spatial variations in fault frequency along the tunnel axis alter the rock mass deformability and strength. Failure mechanisms, orientation and frequency of excavation-induced fractures are significantly influenced by tectonic faults. On the side walls, extensional fracturing tangential to the tunnel circumference was the

  19. Geomechanical analysis of excavation-induced rock mass behavior of faulted Opalinus clay at the Mont Terri underground rock laboratory (Switzerland)

    Energy Technology Data Exchange (ETDEWEB)

    Thoeny, R.

    2014-07-01

    Clay rock formations are potential host rocks for deep geological disposal of nuclear waste. However, they exhibit relatively low strength and brittle failure behaviour. Construction of underground openings in clay rocks may lead to the formation of an excavation damage zone (EDZ) in the near-field area of the tunnel. This has to be taken into account during risk assessment for waste-disposal facilities. To investigate the geomechanical processes associated with the rock mass response of faulted Opalinus Clay during tunnelling, a full-scale ‘mine-by’ experiment was carried out at the Mont Terri Underground Rock Laboratory (URL) in Switzerland. In the ‘mine-by’ experiment, fracture network characteristics within the experimental section were characterized prior to and after excavation by integrating structural data from geological mapping of the excavation surfaces and from four pre- and post-excavation boreholes.The displacements and deformations in the surrounding rock mass were measured using geo-technical instrumentation including borehole inclinometers, extensometers and deflectometers, together with high-resolution geodetic displacement measurements and laser scanning measurements on the excavation surfaces. Complementary data was gathered from structural and geophysical characterization of the surrounding rock mass. Geological and geophysical techniques were used to analyse the structural and kinematic relationships between the natural and excavation-induced fracture network surrounding the ‘mine-by’ experiment. Integrating the results from seismic refraction tomography, borehole logging, and tunnel surface mapping revealed that spatial variations in fault frequency along the tunnel axis alter the rock mass deformability and strength. Failure mechanisms, orientation and frequency of excavation-induced fractures are significantly influenced by tectonic faults. On the side walls, extensional fracturing tangential to the tunnel circumference was the

  20. An review on geology study of carbonaceous-siliceous-pelitic rock type uranium deposit in China and the strategy for its development

    International Nuclear Information System (INIS)

    Zhao Fengmin

    2009-01-01

    Carbonaceous-siliceous-pelitic rock type uranium deposit was founded by Chinese uranium geologist, it refers to the uranium deposit hosted by non or light metamophosed carbonate,siliceous rock, pelitic rock and their intermediates. It is one of the important types uranium deposit in China. A lot of this type deposits have been discovered in China and their temporal-spatial distribution pattern and mineralization features have been basically identified, and the rich experience have layed a good foundation for the future exploration. Although the ore of this type is not favourable economically, it is still available. Because carbonaceous-siliceous-pelitic rock type uranium deposit has great resource potential, metallogenic study and exploration efforts should be projected differentially according to their economic profit so as to meet the uranium resource demand of nuclear power development in China. (authors)

  1. Control of Rock Mechanics in Underground Ore Mining

    Science.gov (United States)

    Golik, V. I.; Efremenkov, A. B.

    2017-07-01

    Performance indicators in underground mining of thick iron fields can be insufficient since geo-mechanic specifics of ore-hosting fields might be considered inadequately, as a consequence, critical deformations and even earth’s surface destruction are possible, lowering the indicators of full subsurface use, this way. The reason for it is the available approach to estimating the performance of mining according to ore excavation costs, without assessing losses of valuable components and damage to the environment. The experimental approach to the problem is based on a combination of methods to justify technical capability and performance of mining technology improvement with regard to geomechanical factors. The main idea of decisions to be taken is turning geo-materials into the condition of triaxial compression via developing the support constructions of blocked up structural rock block. The study was carried out according to an integrated approach based on the analysis of concepts, field observations, and simulation with the photo-elastic materials in conditions of North Caucasus deposits. A database containing information on the deposit can be developed with the help of industrial experiments and performance indicators of the field can be also improved using the ability of ore-hosting fields to develop support constructions, keeping the geo-mechanical stability of the system at lower cost, avoiding ore contamination at the processing stage. The proposed model is a specific one because an adjustment coefficient of natural and anthropogenic stresses is used and can be adopted for local conditions. The relation of natural to anthropogenic factors can make more precise the standards of developed, prepared and ready to excavation ore reserves relying on computational methods. It is possible to minimize critical stresses and corresponding deformations due to dividing the ore field into sectors safe from the standpoint of geo-mechanics, and using less cost

  2. Disc cutter wear and rock texture in hard rock TBM tunneling

    International Nuclear Information System (INIS)

    Koizumi, Yu; Tsusaka, Kimikazu; Tanimoto, Chikaosa; Nakagawa, Shigeo; Fujita, Naoya

    2008-01-01

    Disc cutter wear in TBM tunneling is caused by initial fragmentation of a solid rock face (the primary fragmentation) and fragmentation of residual rock pieces between a cutterhead and the face (the secondary fragmentation). In two projects through sedimentary and granitic rocks, the authors investigated the relationships between the rate of cutter wear caused by the primary fragmentation, point load index and the grain size and contents of abrasive minerals. As a result, it was found that the tensile strength and the mineral contents of rocks significantly influenced the cutter wear in both projects and thus it is necessary to take into account of rock type. (author)

  3. Characterisation of wastewater for modelling of wastewater ...

    African Journals Online (AJOL)

    Bio-process modelling is increasingly used in design, modification and troubleshooting of wastewater treatment plants (WWTPs). Characterisation of the influent wastewater to a WWTP is an important part of developing such a model. The characterisation required for modelling is more detailed than that routinely employed ...

  4. Characterisation and application of NovaFiber lignin

    NARCIS (Netherlands)

    Gosselink, R.J.A.; Snijder, M.H.B.; Kranenbarg, A.; Keijsers, E.R.P.; Jong, de E.; Stigsson, L.L.

    2004-01-01

    Sulphur-free lignin coming from a novel alkaline-pulping process called NovaFiber, which has been developed by KIRAM AB, has been characterised and evaluated for potential applications. A Kraft lignin has been used for comparison. Considering the characterisation results of a NovaFiber softwood and

  5. Rocks Can Wow? Yes, Rocks Can Wow!

    Science.gov (United States)

    Hardman, Sally; Luke, Sue

    2016-01-01

    Rocks and fossils appear in the National Curriculum of England science programmes of study for children in year 3 (ages 7-8). A frequently asked question is "How do you make the classification of rocks engaging?" In response to this request from a school, a set of interactive activities was designed and organised by tutors and students…

  6. Redistribution of Iron and Titanium in High-Pressure Ultramafic Rocks

    Science.gov (United States)

    Crossley, Rosalind J.; Evans, Katy A.; Reddy, Steven M.; Lester, Gregory W.

    2017-11-01

    The redox state of iron in high-pressure serpentinites, which host a significant proportion of Fe3+ in subduction zones, can be used to provide an insight into iron cycling and constrain the composition of subduction zone fluids. In this study, we use oxide and silicate mineral textures, interpretation of mineral parageneses, mineral composition data, and whole rock geochemistry of high-pressure retrogressed ultramafic rocks from the Zermatt-Saas Zone to constrain the distribution of iron and titanium, and iron oxidation state. These data provide an insight on the oxidation state and composition of fluids at depth in subduction zones. Oxide minerals host the bulk of iron, particularly Fe3+. The increase in mode of magnetite and observation of magnetite within antigorite veins in the investigated ultramafic samples during initial retrogression is most consistent with oxidation of existing iron within the samples during the infiltration of an oxidizing fluid since it is difficult to reconcile addition of Fe3+ with the known limited solubility of this species. However, high Ti contents are not typical of serpentinites and also cannot be accounted for by simple mixing of a depleted mantle protolith with the nearby Allalin gabbro. Titanium-rich phases coincide with prograde metamorphism and initial exhumation, implying the early seafloor and/or prograde addition and late mobilization of Ti. If Ti addition has occurred, then the introduction of Fe3+, also generally considered to be immobile, cannot be disregarded. We explore possible transport vectors for Ti and Fe through mineral texture analysis.

  7. Characterisation of nanomaterial hydrophobicity using engineered surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Desmet, Cloé; Valsesia, Andrea; Oddo, Arianna; Ceccone, Giacomo; Spampinato, Valentina; Rossi, François; Colpo, Pascal, E-mail: pascal.colpo@ec.europa.eu [Directorate Health, Consumer and Reference Materials, Consumer Products Safety Unit (Italy)

    2017-03-15

    Characterisation of engineered nanomaterials (NMs) is of outmost importance for the assessment of the potential risks arising from their extensive use. NMs display indeed a large variety of physico-chemical properties that drastically affect their interaction with biological systems. Among them, hydrophobicity is an important property that is nevertheless only slightly covered by the current physico-chemical characterisation techniques. In this work, we developed a method for the direct characterisation of NM hydrophobicity. The determination of the nanomaterial hydrophobic character is carried out by the direct measurement of the affinity of the NMs for different collectors. Each collector is an engineered surface designed in order to present specific surface charge and hydrophobicity degrees. Being thus characterised by a combination of surface energy components, the collectors enable the NM immobilisation with surface coverage in relation to their hydrophobicity. The experimental results are explained by using the extended DLVO theory, which takes into account the hydrophobic forces acting between NMs and collectors.

  8. Aespoe Hard Rock Laboratory. Annual Report 2001

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-09-01

    during 2001 and the work within Task 6, Performance Assessment Modelling Using Site Characterisation Data, has started. The Aespoe HRL makes it possible to demonstrate and perform full-scale tests of the function of different components of the repository system that are important for the performance and the long term safety of a repository. It is also important to show that high quality can be achieved in design, construction, and operation of the repository. To fulfil these tasks several projects are performed, e. g. Demonstration of Repository Technology, Prototype Repository, Backfill and Plug Test, Canister Retrieval Test, Long Term Tests of Buffer Material, and Pillar Stability Experiment. The focus of the Task Force on Engineered Barrier Systems during 2001 has been on modelling of THM processes taking place in the bentonite buffer during saturation. This is also the prime modelling objective in the Prototype Repository and the work has therefore been conducted under the umbrella of the Prototype Repository. The operation of the facility has worked smoothly. A number of new projects concerning safety, security and reliability have been initiated, started or completed during 2001. To meet the need for additional office space to host the staff of the site investigation in Oskarshamn a temporary barrack was built and an application for planning permission for additional extension of the Aespoe surface facility has been submitted. An extensive rock reinforcement programme was finalised in February 2001. The programme comprises complementary shotcreting, injections, bolting and mounting of mesh. Replacement of corroded light equipment in the deeper half of the tunnel, 220-450 m level, and replacement of sealing on the water pipes in the shaft, 350-450 m level, have been completed. The main goal for the information group is to create public acceptance for SKB's activities in co-operation with other departments at SKB. This is achieved by presenting information about

  9. Aespoe Hard Rock Laboratory. Annual Report 2001

    International Nuclear Information System (INIS)

    2002-09-01

    and the work within Task 6, Performance Assessment Modelling Using Site Characterisation Data, has started. The Aespoe HRL makes it possible to demonstrate and perform full-scale tests of the function of different components of the repository system that are important for the performance and the long term safety of a repository. It is also important to show that high quality can be achieved in design, construction, and operation of the repository. To fulfil these tasks several projects are performed, e. g. Demonstration of Repository Technology, Prototype Repository, Backfill and Plug Test, Canister Retrieval Test, Long Term Tests of Buffer Material, and Pillar Stability Experiment. The focus of the Task Force on Engineered Barrier Systems during 2001 has been on modelling of THM processes taking place in the bentonite buffer during saturation. This is also the prime modelling objective in the Prototype Repository and the work has therefore been conducted under the umbrella of the Prototype Repository. The operation of the facility has worked smoothly. A number of new projects concerning safety, security and reliability have been initiated, started or completed during 2001. To meet the need for additional office space to host the staff of the site investigation in Oskarshamn a temporary barrack was built and an application for planning permission for additional extension of the Aespoe surface facility has been submitted. An extensive rock reinforcement programme was finalised in February 2001. The programme comprises complementary shotcreting, injections, bolting and mounting of mesh. Replacement of corroded light equipment in the deeper half of the tunnel, 220-450 m level, and replacement of sealing on the water pipes in the shaft, 350-450 m level, have been completed. The main goal for the information group is to create public acceptance for SKB's activities in co-operation with other departments at SKB. This is achieved by presenting information about SKB, the

  10. Hot Dry Rock; Geothermal Energy

    Energy Technology Data Exchange (ETDEWEB)

    None

    1990-01-01

    The commercial utilization of geothermal energy forms the basis of the largest renewable energy industry in the world. More than 5000 Mw of electrical power are currently in production from approximately 210 plants and 10 000 Mw thermal are used in direct use processes. The majority of these systems are located in the well defined geothermal generally associated with crustal plate boundaries or hot spots. The essential requirements of high subsurface temperature with huge volumes of exploitable fluids, coupled to environmental and market factors, limit the choice of suitable sites significantly. The Hot Dry Rock (HDR) concept at any depth originally offered a dream of unlimited expansion for the geothermal industry by relaxing the location constraints by drilling deep enough to reach adequate temperatures. Now, after 20 years intensive work by international teams and expenditures of more than $250 million, it is vital to review the position of HDR in relation to the established geothermal industry. The HDR resource is merely a body of rock at elevated temperatures with insufficient fluids in place to enable the heat to be extracted without the need for injection wells. All of the major field experiments in HDR have shown that the natural fracture systems form the heat transfer surfaces and that it is these fractures that must be for geothermal systems producing from naturally fractured formations provide a basis for directing the forthcoming but, equally, they require accepting significant location constraints on HDR for the time being. This paper presents a model HDR system designed for commercial operations in the UK and uses production data from hydrothermal systems in Japan and the USA to demonstrate the reservoir performance requirements for viable operations. It is shown that these characteristics are not likely to be achieved in host rocks without stimulation processes. However, the long term goal of artificial geothermal systems developed by systematic

  11. Characterizing and modelling the radionuclide transport properties of fracture zones in plutonic rocks of the Canadian Shield

    International Nuclear Information System (INIS)

    Davison, C.C.; Kozak, E.T.; Frost, L.H.; Everitt, R.A.; Brown, A.; Gascoyne, M.; Scheier, N.W.

    1999-01-01

    Plutonic rocks of the Canadian Shield were investigated as a potential host medium for nuclear fuel waste disposal of used CANDU nuclear fuel. Field investigations at several geologic research areas on the Shield have shown that major fracture zones are the dominant pathways for the large scale movement of groundwater and solutes through plutonic rock bodies. Because of this, a significant amount of the geoscience work has focused on methods to identify, characterize and model the radionuclide transport properties of major fracture zones in the fractured plutonic rocks of the Shield. In order to quantify the transport properties of such fracture zones a series of, groundwater tracer tests were performed over a period of several years in several major, low dipping fracture zones. Sixteen tracer tests were performed using dipole recirculation methods to evaluate transport over distance scales ranging from 17 m to 700 m. It was concluded that only tracer tests can provide useful estimates of the effective porosity and dispersivity characteristics of these large fracture zones in plutonic rocks of the Canadian Shield. (author)

  12. Modelling the diffusion-available pore space of an unaltered granitic rock matrix using a micro-DFN approach

    Science.gov (United States)

    Svensson, Urban; Löfgren, Martin; Trinchero, Paolo; Selroos, Jan-Olof

    2018-04-01

    In sparsely fractured rock, the ubiquitous heterogeneity of the matrix, which has been observed in different laboratory and in situ experiments, has been shown to have a significant influence on retardation mechanisms that are of importance for the safety of deep geological repositories for nuclear waste. Here, we propose a conceptualisation of a typical heterogeneous granitic rock matrix based on micro-Discrete Fracture Networks (micro-DFN). Different sets of fractures are used to represent grain-boundary pores as well as micro fractures that transect different mineral grains. The micro-DFN model offers a great flexibility in the way inter- and intra-granular space is represented as the different parameters that characterise each fracture set can be fine tuned to represent samples of different characteristics. Here, the parameters of the model have been calibrated against experimental observations from granitic rock samples taken at Forsmark (Sweden) and different variant cases have been used to illustrate how the model can be tied to rock samples with different attributes. Numerical through-diffusion simulations have been carried out to infer the bulk properties of the model as well as to compare the computed mass flux with the experimental data from an analogous laboratory experiment. The general good agreement between the model results and the experimental observations shows that the model presented here is a reliable tool for the understanding of retardation mechanisms occurring at the mm-scale in the matrix.

  13. Computer modelling of stresses in rock. Proceedings of a technical session

    International Nuclear Information System (INIS)

    Come, B.

    1984-01-01

    A part of the research carried out, at Community level, in the field of radioactive waste disposal, concerns the calculation of stresses in the host formations. This particular aspect of rock mechanics studies is of great importance: (a) for designing and constructing safe underground repositories; (b) to predict the ''post-closure'' behaviour of the rock mass, particularly when submitted to heat release from high-level waste. Adequate calculation tools must be developed for these purposes. In some cases, analytical solutions can be obtained; most of the time, finite-element computer codes are the only method able to solve these difficult problems. CEC contracting partners were invited to present the results of their work in this field, for the period 1980-1983, to identify the issues which can be considered as solved, and to make recommendations for further research. The presentations made, together with the discussions and conclusions, are grouped in this report

  14. Fault rocks from the SAFOD core samples : implications for weakening at shallow depths along the San Andreas Fault, California

    NARCIS (Netherlands)

    Holdsworth, R.E.; van Diggelen, E.W.E.; Spiers, C.J.; Bresser, J.H.P. de; Walker, R.J.; Bown, L.

    2011-01-01

    The drilling of a deep borehole across the actively creeping Parkfield segment of the San Andreas Fault Zone (SAFZ), California, and collection of core materials permit direct geological study of fault zone processes at 2–3 km depth. The three drill cores sample both host and fault rocks and pass

  15. Preliminary study of uranium favorability of upper cretaceous, paleocene, and lower eocene rocks of the Bighorn Basin, Wyoming and Montana

    International Nuclear Information System (INIS)

    Hesse, S.L.; Dunagan, J.F. Jr.

    1978-02-01

    This report presents an evaluation of the uranium favorability of continental sediments of the Upper Cretaceous Lance, Paleocene Polecat Bench, and lower Eocene Willwood Formations in the Bighorn Basin of Wyoming and Montana, an intermontane structural basin of Laramide age. Previous work dealing with the Bighorn Basin was reviewed, and field investigations were carried out in the spring and summer of 1976. Subsurface data were collected and results of surface and subsurface investigations were evaluated with respect to uranium favorability. Precambrian plutonic and metamorphic rocks and Tertiary tuffaceous rocks in the Bighorn Basin and bordering uplifts are considered insignificant as source rocks, although the Wiggins Formation (White River equivalent) cannot be evaluated as a possible source because of a lack of data. Potential host rocks locally show only limited favorability. Lithology of strata exposed along the western and southern basin margins is more favorable than that of rocks in the central and eastern parts of the basin, but there is little organic material, pyrite, or other reducing agents in these rocks. Strata of the Lance, Polecat Bench, and Willwood Formations in the Bighorn Basin are considered generally unfavorable for sandstone uranium deposits

  16. A survey of natural radiation levels in soils and rocks from Aliaga-Foca region in Izmir, Turkey

    International Nuclear Information System (INIS)

    Fuesun cam, N.; Oezken, I.; Yaprak, G.

    2013-01-01

    The gamma spectroscopic analysis of 226 Ra, 232 Th and 40 K has been carried out in surface soil samples collected from Aliaga-Foca industrial region. The rock samples as parent materials of the soils are also collected and analysed for relevant radionuclides in order to evaluate the natural radiation levels. In the present study, the mean activity concentrations and ranges of the related radionuclides in the soil samples from 60 sites distributed all over the region are as follows: 226 Ra is 38 (14-123) Bq kg -1 ; 232 Th, 63 (27-132) Bq kg -1 and 40 K , 633 (141-1666) Bq kg -1 . Meanwhile, the ranges of natural radionuclide activities in the rock samples characterising the region are 41-95 Bq kg -1 for 226 Ra, 10-122 Bq kg -1 for 232 Th and 264-1470 Bq kg -1 for 40 K , respectively. Based on the available data, the radiation hazard parameters associated with the surveyed soils/rocks are calculated and the results do not exceed the permissible recommended values except for soils originated from Foca rhyolites and tuffs. Furthermore, the collected data allowed for the mapping of the measured activities and corresponding gamma dose rates. (authors)

  17. Rock Physics

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke

    2017-01-01

    Rock physics is the discipline linking petrophysical properties as derived from borehole data to surface based geophysical exploration data. It can involve interpretation of both elastic wave propagation and electrical conductivity, but in this chapter focus is on elasticity. Rock physics is based...... on continuum mechanics, and the theory of elasticity developed for statics becomes the key to petrophysical interpretation of velocity of elastic waves. In practice, rock physics involves interpretation of well logs including vertical seismic profiling (VSP) and analysis of core samples. The results...

  18. Mineral and rock chemistry of Mata da Corda Kamafugitic Rocks (Minas Gerais State, Brazil)

    International Nuclear Information System (INIS)

    Albuquerque Sgarbi, Patricia B. de; Valenca, Joel G.

    1995-01-01

    The volcanic rocks of the Mata da Corda Formation (Upper Cretaceous) in Minas Gerais, Brazil, are mafic potassic to ultra potassic rocks of kamafugitic affinity containing essentially clinopyroxenes, perovskite, magnetite and occasionally olivine, phlogopite, melilite pseudomorphs and apatite. The felsic phases are kalsilite and/or leucite pseudomorphs. The rocks are classified as mafitites, leucitites and kalsilitites. The analysis of the available data of the rocks studied, based on the relevant aspects of the main proposals for the classification of alkaline mafic to ultramafic potassic rocks leads to the conclusion that Sahama's (1974) proposal to divide potassium rich alkaline rocks in two large families is the one to which the Mata da Corda rocks adapt best. According to this and the data in the literature on the mineralogy and mineral and rock chemistries of the other similar occurrences, these rocks may be interpreted as alkaline potassic to ultra potassic rocks of hamafugitic affinity. 11 figs., 5 tabs

  19. HostPhinder: A Phage Host Prediction Tool

    Directory of Open Access Journals (Sweden)

    Julia Villarroel

    2016-05-01

    Full Text Available The current dramatic increase of antibiotic resistant bacteria has revitalised the interest in bacteriophages as alternative antibacterial treatment. Meanwhile, the development of bioinformatics methods for analysing genomic data places high-throughput approaches for phage characterization within reach. Here, we present HostPhinder, a tool aimed at predicting the bacterial host of phages by examining the phage genome sequence. Using a reference database of 2196 phages with known hosts, HostPhinder predicts the host species of a query phage as the host of the most genomically similar reference phages. As a measure of genomic similarity the number of co-occurring k-mers (DNA sequences of length k is used. Using an independent evaluation set, HostPhinder was able to correctly predict host genus and species for 81% and 74% of the phages respectively, giving predictions for more phages than BLAST and significantly outperforming BLAST on phages for which both had predictions. HostPhinder predictions on phage draft genomes from the INTESTI phage cocktail corresponded well with the advertised targets of the cocktail. Our study indicates that for most phages genomic similarity correlates well with related bacterial hosts. HostPhinder is available as an interactive web service [1] and as a stand alone download from the Docker registry [2].

  20. Detailed rock failure susceptibility mapping in steep rocky coasts by means of non-contact geostructural surveys: the case study of the Tigullio Gulf (Eastern Liguria, Northern Italy

    Directory of Open Access Journals (Sweden)

    P. De Vita

    2012-04-01

    Full Text Available In this study, an engineering geological analysis for the assessment of the rock failure susceptibility of a high, steep, rocky coast was developed by means of non-contact geostructural surveys. The methodology was applied to a 6-km coastal cliff located in the Gulf of Tigullio (Northern Tyrrhenian Sea between Rapallo and Chiavari.

    The method is based on the geostructural characterisation of outcropping rock masses through meso- and macroscale stereoscopic analyses of digital photos that were taken continuously from a known distance from the coastline. The results of the method were verified through direct surveys of accessible sample areas. The rock failure susceptibility of the coastal sector was assessed by analysing the fundamental rock slope mechanisms of instability and the results were implemented into a Geographic Information System (GIS.

    The proposed method is useful for rock failure susceptibility assessments in high, steep, rocky coastal areas, where accessibility is limited due to cliffs or steep slopes. Moreover, the method can be applied to private properties or any other area where a complete and systematic analysis of rock mass structural features cannot be achieved.

    Compared to direct surveys and to other non-contact methods based on digital terrestrial photogrammetry, the proposed procedure provided good quality data of the structural features of the rock mass at a low cost. Therefore, the method could be applied to similar coastal areas with a high risk of rock failure occurrence.

  1. Waste package characterisation

    Energy Technology Data Exchange (ETDEWEB)

    Sannen, L.; Bruggeman, M.; Wannijn, J.P

    1998-09-01

    Radioactive wastes originating from the hot labs of the Belgian Nuclear Research Centre SCK-CEN contain a wide variety of radiotoxic substances. The accurate characterisation of the short- and long-term radiotoxic components is extremely difficult but required in view of geological disposal. This paper describes the methodology which was developed and adopted to characterise the high- and medium-level waste packages at the SCK-CEN hot laboratories. The proposed method is based on the estimation of the fuel inventory evacuated in a particular waste package; a calculation of the relative fission product contribution on the fuel fabrication and irradiation footing; a comparison of the calculated, as expected, dose rate and the real measured dose rate of the waste package. To cope with the daily practice an appropriate fuel inventory estimation route, a user friendly computer programme for fission product and corresponding dose rate calculation, and a simple dose rate measurement method have been developed and implemented.

  2. Waste package characterisation

    International Nuclear Information System (INIS)

    Sannen, L.; Bruggeman, M.; Wannijn, J.P.

    1998-09-01

    Radioactive wastes originating from the hot labs of the Belgian Nuclear Research Centre SCK-CEN contain a wide variety of radiotoxic substances. The accurate characterisation of the short- and long-term radiotoxic components is extremely difficult but required in view of geological disposal. This paper describes the methodology which was developed and adopted to characterise the high- and medium-level waste packages at the SCK-CEN hot laboratories. The proposed method is based on the estimation of the fuel inventory evacuated in a particular waste package; a calculation of the relative fission product contribution on the fuel fabrication and irradiation footing; a comparison of the calculated, as expected, dose rate and the real measured dose rate of the waste package. To cope with the daily practice an appropriate fuel inventory estimation route, a user friendly computer programme for fission product and corresponding dose rate calculation, and a simple dose rate measurement method have been developed and implemented

  3. The abundance and distribution of uranium in some oceanic, continental ultramafic inclusions and host basalts

    International Nuclear Information System (INIS)

    Hamilton, E.I.

    1975-01-01

    The abundance and distribution of uranium in various continental and oceanic ultramafic inclusions and host basalts are reported. Uranium was determined by neutron activation (fission products, fission tracks and delayed-neutron methods) and alpha-particle autoradiography; data is also reported for the uranium content of various USGS standard rock powders. The concentration of uranium in both oceanic and continental samples is similar, levels are controlled by mineral compositions and their relative abundance in different rock types. Highest levels are found in feldspathic and lowest in olivine-rich inclusions. Uranium is enriched in mylonitised samples and along some inter-crystal boundaries. With the exception of some apatites, highest levels of uranium are in clinopyroxenes (chrome) and lowest in olivines; no enrichment of uranium in orthopyroxenes was observed. Attention is drawn to the problem of obtaining representative samples from the sea floor which have not been altered by saline solutions and the identification of uranium and daughter products present along inter-crystal boundaries. Differences in observed heat flow between continental and oceanic areas may reflect inadequate sampling of representative rock types present below the sea floor and lack of information for the true abundance and distribution of uranium in such rocks

  4. The 13 November 2007 rock-fall at Viale Tiziano in Rome (Italy

    Directory of Open Access Journals (Sweden)

    M. Amanti

    2012-05-01

    Full Text Available The aim of the study was to perform a study on the western slope of the Monti Parioli hill (Rome, Italy affected by frequent rock-fall phenomena, such as the one that occurred on 13 November 2007.

    This goal was achieved by defining a detailed reconstruction of the stratigraphical, geological and geomechanical structure of the slope and by conducting a back-analysis of the rock-fall event using 2-D and 3-D modeling tools.

    The reconstruction of the slope's geological structure, characterized by the presence of two anthropogenic cavity systems, and the characterisation of geomechanical properties of outcropping terrains have been realized by means of a detailed geological survey and a campaign of direct and indirect investigations. Therefore, continuous rotary, coring boreholes up to 60 m, collecting undisturbed samples for laboratory tests and performing direct investigations such as SPTs and pressuremeter tests were carried out. The indirect investigations included electrical tomography surveys, linear surface seismic refraction surveys and seismic cross-hole tests.

    Using the reconstructed geological-technical model, it was possible to define the stability conditions of the slope at the time of collapse by using a computational two-dimensional explicit finite difference program (FLAC and a 3-D finite element analysis (FEMLAB.

  5. Evaluation of Uranium depositional system in sedimentary rocks of Sibolga formation, Tapanuli Tengah

    International Nuclear Information System (INIS)

    I Gde Sukadana; Heri Syaeful

    2016-01-01

    Uranium in nature formed in various deposit type, depends on its sources, process, and depositional environments. Uranium occurrence in Sibolga, hosted in sedimentary rocks of Sibolga Formation, is properly potential to develop; nevertheless, the depositional pattern and uranium mineralization process so far had not been recognized. The research aim is to determine the rock distribution patterns and the existence of uranium grade anomalies based on surface geology and borehole log data. Mineralization occurrences from borehole log data distributed from basalt conglomerate unit (Kgl 1), sandstone 1 unit (Bp 1), conglomerate 2 unit (Kgl 2), and sandstone 2 unit (Bp 2) with their distribution and thickness are thinning to the top. Mineralization distribution in the eastern area, mainly on Kgl 1 unit, dominated by detritus materials from epi-genetic depositional in the form of monazite which is formed along with the formation of granite as its source rock. Meanwhile, mineralization on the upper rocks units formed a channel pattern trending northeast-southwest, which formed in syn-genetic process consist of uraninite, carnotite, and coffinite. Sibolga Formation deposition originated from east to west and uranium deposit formed because of the differences of depositional environment from oxidation in the east to the more reductive in the southwest. The increasing of organic materials in southwest basin caused the reduction condition of depositional environment. (author)

  6. Rock History and Culture

    OpenAIRE

    Gonzalez, Éric

    2013-01-01

    Two ambitious works written by French-speaking scholars tackle rock music as a research object, from different but complementary perspectives. Both are a definite must-read for anyone interested in the contextualisation of rock music in western popular culture. In Une histoire musicale du rock (i.e. A Musical History of Rock), rock music is approached from the point of view of the people – musicians and industry – behind the music. Christophe Pirenne endeavours to examine that field from a m...

  7. Factors controlling Li concentration and isotopic composition in formation waters and host rocks of Marcellus Shale, Appalachian Basin

    Science.gov (United States)

    Phan, Thai T.; Capo, Rosemary C; Stewart, Brian W.; Macpherson, Gwen; Rowan, Elisabeth L.; Hammack, Richard W.

    2015-01-01

    In this study, water and whole rock samples from hydraulically fractured wells in the Marcellus Shale (Middle Devonian), and water from conventional wells producing from Upper Devonian sandstones were analyzed for lithium concentrations and isotope ratios (δ7Li). The distribution of lithium concentrations in different mineral groups was determined using sequential extraction. Structurally bound Li, predominantly in clays, accounted for 75-91 wt. % of total Li, whereas exchangeable sites and carbonate cement contain negligible Li (shale in Greene Co., Pennsylvania, and Tioga Co., New York, ranged from -2.3 to + 4.3‰, similar to values reported for other shales in the literature. The δ7Li values in shale rocks with stratigraphic depth record progressive weathering of the source region; the most weathered and clay-rich strata with isotopically light Li are found closest to the top of the stratigraphic section. Diagenetic illite-smectite transition could also have partially affected the bulk Li content and isotope ratios of the Marcellus Shale.

  8. Interaction of the lithospheric mantle and crustal melts for the generation of the Horoz pluton (Niğde, Turkey: whole-rock geochemical and Sr–Nd–Pb isotopic evidence

    Directory of Open Access Journals (Sweden)

    Kerim Kocak

    2016-08-01

    Full Text Available The Horoz pluton includes granitic and granodioritic rocks, with widespread mafic microgranular enclaves (MMEs. Petrochemically, the rocks of the pluton show calc-alkaline to shoshonitic and metaluminous to slightly peraluminous composition. The rocks also exhibit an enrichment in large ion lithophile elements, e.g. Rb, K, and depletions of high field strength elements such as Y, Lu, and Mg#, Ni, with a slightly concave-upward rare earth element pattern. Both granitic and granodioritic rocks exhibit geochemical characteristics of tonalite, trondhjemite and granodiorite assemblages, possibly developed by the partial melting of a thickened lower crust. The granitoids have high concentrations of Na2O (2.6–4.5 wt%, Sr (347–599 ppm, intermediate-high (La/YbN (8.2–18.1, mostly >11 , Al2O3 (13.2–16.9 wt%, average 15.3 wt%, low MgO (0.2–1.4 wt%, average 0.84 wt% and Co (0.7–10.3 ppm. The MMEs include higher Na2O (4.5–5.5 wt%, Sr (389–1149 ppm, Al2O3 (16.9–19.2 wt%, average 17.8 wt%, MgO (1.4–4.4 wt%, average 2.75 wt% and Co (6.2–18.7 ppm contents in comparison with that of their hosts. There is a lack of negative Eu anomalies, except a few samples. Both host rocks and MMEs have a low initial 87Sr/86Sr ratio (respectively 0.7046–0.7051 and 0.7047–0.7058, low eNd value (–1.8 to –0.2 and –0.6 to 0.7 at 50 Ma and highly radiogenic 208Pb/204Pb ratios (39.43–39.47 and 39.39–39.54. Whole-rock chemistry and isotopic data suggest that parent magmas of both MMEs and their hosts have derived from melts of the mixing between the lithospheric mantle and crustal end members, than fractional crystallization processes in crustal levels.

  9. The characterisation of precipitated magnetites

    International Nuclear Information System (INIS)

    Rush, D.F.; Segal, D.L.

    1982-06-01

    Methods are described for the preparation of magnetite by precipitation from aqueous solutions of iron(II) and iron(III) salts. The magnetites have been characterised by transmission electron microscopy, chemical analysis and X-ray diffraction. Transmission Moessbauer spectroscopy has also been used to characterise precipitated magnetites and a comparison of the spectra has been made with those obtained from nickel ferrite and hydrated ferric oxides. The hydrothermal stability of magnetite at 573 K has also been investigated. This work is relevant to corrosion processes that can occur in the water coolant circuits of nuclear reactors. (author)

  10. Transferability of geodata from European to Canadian (Ontario) sedimentary rocks to study gas transport from nuclear wastes repositories

    International Nuclear Information System (INIS)

    Fall, M.; Ghafari, H.; Evgin, E.; Nguyen, T.S.

    2010-01-01

    , most of these studies, especially the gas migration tests, were conducted in European sedimentary rocks (Opalinus Clay in Benken and Mont Terri, Callovo-Oxfordian Clay at Bure). At present, gas transport data specific for Ontario sedimentary rocks are not available; the input parameters for mathematical models have to be inferred from the European database. This paper presents a methodological approach and the results of a study to assess the usefulness and transferability of geo-data from European to Ontario sedimentary rocks to model the THMC processes associated with gas migration in Ontario. Furthermore, predictive models (based on advanced soft-computing methods) to estimate the gas transport parameters of the Ontario rocks from data on European sedimentary rocks are presented and discussed. The paper is divided into three main parts: - In the first part, the main similarities and differences between the thermal, hydraulic, geochemical and geomechanical properties of the host rocks of the proposed Ontario DGR and European DGRs are highlighted and discussed, based on a comparison of the collected technical information on sedimentary rocks in Ontario and Europe. - The second part includes an analysis of the quality (e.g., uncertainties), suitability and transferability of the data gathered with respect to the investigation of gas generation and migration in a potential repository in Ontario's sedimentary rocks. - In the third part, a quantitative analysis of the transferability of the data is conducted by using advanced soft computing methods (e.g., Self Organizing Neuro-Fuzzy Inference System (SONFIS)). Predictive models are developed to predict the relevant parameters that are necessary to model and analyze gas transport in the study DGR in Ontario. The validation results show good agreement between the predicted and measured field values. In conclusion, this study has allowed us to identify the similarities and differences between the Ontario and European

  11. Summary review of rock mechanics workshop on radioactive waste disposal

    International Nuclear Information System (INIS)

    Carter, N.L.; Goodman, R.E.; Merrill, R.H.

    1977-01-01

    Presentations, critiques and recommendations for the disposal of commercial radioactive waste based upon an analysis of the information presented at the Rock Mechanics Review/Workshop, Denver, Colorado, December 16-17, 1976 are summarized. The workshop, comprised of both formal and informal sessions, with about 50 participants, was hosted by RE/SPEC Inc. and Dr. Paul F. Gnirk, President and was sponsored by the Office of Waste Isolation (OWI), led by Dr. William C. McClain. The panel of reviewers, responsible for this report, consisted of Neville L. Carter, Richard E. Goodman, and Robert H. Merrill. These panel members were selected not only on the basis of their experience in various aspects of Rock Mechanics and Mining Engineering but also because they have had no previous active participation in problems concerning disposal of radioactive waste. By way of a general comment, the review panel was very favorably impressed with the Rock Mechanics research efforts, supported by OWI, on this problem and with the level of technical competence of those carrying out the research. Despite the rather preliminary nature of the results presented and the youth of the program itself, it is clear that the essential ingredients for a successful program are at hand, especially as regards disposal in natural salt formations. These include laboratory studies of appropriate rock deformation, numerical analyses of thermal and mechanical stresses around openings, and in situ field tests. We shall comment on each of these three major areas in turn. We shall then offer recommendations for their improvement, and, finally, we shall make more general recommendations for future considerations of the OWI radioactive waste disposal program

  12. Rock-Bound Arsenic Influences Ground Water and Sediment Chemistry Throughout New England

    Science.gov (United States)

    Robinson, Gilpin R.; Ayotte, Joseph D.

    2007-01-01

    The information in this report was presented at the Northeastern Region Geological Society of America meeting held March 11-14, 2007, in Durham, New Hampshire. In the New England crystalline bedrock aquifer, concentrations of arsenic that exceed the drinking water standard of 10 ?g/L occur most frequently in ground water from wells sited in specific metamorphic and igneous rock units. Geochemical investigations indicate that these geologic units typically have moderately elevated whole-rock concentrations of arsenic compared to other rocks in the region. The distribution of ground water wells with As > 5 ?g/L has a strong spatial correlation with specific bedrock units where average whole-rock concentrations of arsenic exceed 1.1 mg/kg and where geologic and geochemical factors produce high pH ground water. Arsenic concentrations in stream sediments collected from small drainages reflect the regional distribution of this natural arsenic source and have a strong correlation with both rock chemistry and the distribution of bedrock units with elevated arsenic chemistry. The distribution of ground water wells with As > 5 ?g/L has a strong spatial correlation with the distribution of stream sediments where concentrations of arsenic exceed 6 mg/kg. Stream sediment chemistry also has a weak correlation with the distribution of agricultural lands where arsenical pesticides were used on apple, blueberry, and potato crops. Elevated arsenic concentrations in bedrock wells, however, do not correlate with agricultural areas where arsenical pesticides were used. These results indicate that both stream sediment chemistry and the solubility and mobility of arsenic in ground water in bedrock are influenced by host-rock arsenic concentrations. Stream sediment chemistry and the distribution of geologic units have been found to be useful parameters to predict the areas of greatest concern for elevated arsenic in ground water and to estimate the likely levels of human exposure to

  13. The Jettencave, Southern Harz Mountains, Germany: Geophysical observations and a structural model of a shallow cave in gypsum/anhydrite-bearing rocks

    Science.gov (United States)

    Kaufmann, Georg; Romanov, Douchko

    2017-12-01

    Gypsum and anhydrite are soluble rocks, where fissures and bedding partings can be enlarged with time by the dissolution of the mineral species through water. The selective enlargement results in sub-surface voids acting as preferential flow path for the drainage of the rock. With time, larger cavities develop, and a network of cave passages can evolve. If the enlarged cave voids are not too deep under the surface, geophysical measurements can be used to detect, identify and trace these structures. We have used gravity measurements (GRAV), electrical resistivity imaging (ERI), self-potential measurements (SP), electrical conductivity measurements (EC), and ground-penetrating radar (GPR) above the cave Jettenhöhle, a cave located in the southern Harz Mountains in Germany. The Jettencave is developed in the Hauptanhydrit formation of the Permian Zechstein sequence, characterised by large breakdown rooms and an exposed water table. The overburden of the cave is only around 10-15 m, and dolomitic rocks are located in close vicinity. We present results from our geophysical surveys in vicinity of the cave. We are able to identify the cave geometry from GRAV, ERI, and GPR measurements, which distinguish the local lithology of the Permian Zechstein rocks in the area. From the ERI and EC measurements, we derive information on the void volume in the soluble rocks. We finally present a three-dimensional structural model of the Jettencave and its surroundings, based on our geophysical results and the hydrological interpretation.

  14. Origin of convex tetrads in rare earth element patterns of hydrothermally altered siliceous igneous rocks from the Zinnwald Sn W deposit, Germany

    Science.gov (United States)

    Monecke, T.; Dulski, P.; Kempe, U.

    2007-01-01

    The chondrite-normalized rare earth element (REE) patterns of whole rock samples from evolved granitic systems hosting rare metal deposits sometimes show a split into four consecutive curved segments, referred to as tetrads. In the present contribution, a rigorous statistical method is proposed that can be used to test whether geological significance should be attributed to tetrads that are only of limited size. The method involves a detailed evaluation of element and sample specific random and systematic errors that are constrained on the basis of independent repeated preparations and analyses of sample and reference materials. Application of the proposed method to samples from the granite-hosted Zinnwald Sn-W deposit, Germany, revealed that at least two tetrads in normalized whole rock REE patterns have to be analytically significant to rule out that fractional crystallization led to the unusual behavior of the REEs. Based on the analysis of altered albite granite and greisen samples from the endocontact of the Zinnwald granite massif, it is demonstrated that the lanthanide tetrad effect is responsible for the formation of the convex tetrads. Geological and petrological evidence suggests that the tetrads in the samples developed prior to greisenization and related cassiterite precipitation. In contrast to the endocontact samples, the rhyolitic wall rocks are typified by normalized REE patterns having tetrads that are variable in size and frequently close to the limit of analytical significance. The sizes of the tetrads apparently correlate with the intensity of albitization, but show no relation to subsequent alteration processes including greisenization and low-temperature argillization. This observation proves that curved segments in normalized whole rock REE patterns can be introduced during hydrothermal fluid-rock interaction.

  15. Hijacked then lost in translation: the plight of the recombinant host cell in membrane protein structural biology projects.

    Science.gov (United States)

    Bill, Roslyn M; von der Haar, Tobias

    2015-06-01

    Membrane protein structural biology is critically dependent upon the supply of high-quality protein. Over the last few years, the value of crystallising biochemically characterised, recombinant targets that incorporate stabilising mutations has been established. Nonetheless, obtaining sufficient yields of many recombinant membrane proteins is still a major challenge. Solutions are now emerging based on an improved understanding of recombinant host cells; as a 'cell factory' each cell is tasked with managing limited resources to simultaneously balance its own growth demands with those imposed by an expression plasmid. This review examines emerging insights into the role of translation and protein folding in defining high-yielding recombinant membrane protein production in a range of host cells. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. Rapid formation of rock armour for soil - rock fragment mixture during simulated rainfall

    Science.gov (United States)

    Poultney, E.; McGrath, G. S.; Hinz, C.

    2009-04-01

    Preventing erosion is an important issue in disturbed semi-arid and arid landscapes. This is in particular of highest importance for mining companies while undertaking land rehabilitation. An onsite investigation of the impact of surface rock fragments on erosion was conducted at Telfer goldmine in the Great Sandy Desert, Western Australia. The study site is a waste rock dump designed to mimic the concave slope of a natural mesa to both discourage erosion and blend in with its natural surroundings. Four treatments were used to construct the slope: two are topsoil mixed with rock fragments, and two are unmixed topsoil. A field study investigating erosion rills, particle size distribution, rock fragment coverage surface roughness and vegetation was carried out to determine changes down and across slope. The treatments constructed by mixing topsoil and rock fragments are more stable and show rock fragment distributions that more closely resemble patterns found on natural mesas surrounding Telfer. A controlled study using trays of topsoil mixed with rock fragment volumes of 50%, 60%, 70% and 80% were used to investigate how varying mixtures of rock fragments and topsoil erode using rainfall intensities between 20 and 100 mm h-1. Two runs of 25 minutes each were used to assess the temporal evolution of rock armouring. Surface coverage results converged for the 50%, 60% and 70% mixtures after the first run to coverage of about 90%, suggesting that fine sediment proportion does not affect rate and degree of rock armouring.

  17. The role of host traits, season and group size on parasite burdens in a cooperative mammal.

    Directory of Open Access Journals (Sweden)

    Hermien Viljoen

    Full Text Available The distribution of parasites among hosts is often characterised by a high degree of heterogeneity with a small number of hosts harbouring the majority of parasites. Such patterns of aggregation have been linked to variation in host exposure and susceptibility as well as parasite traits and environmental factors. Host exposure and susceptibility may differ with sexes, reproductive effort and group size. Furthermore, environmental factors may affect both the host and parasite directly and contribute to temporal heterogeneities in parasite loads. We investigated the contributions of host and parasite traits as well as season on parasite loads in highveld mole-rats (Cryptomys hottentotus pretoriae. This cooperative breeder exhibits a reproductive division of labour and animals live in colonies of varying sizes that procreate seasonally. Mole-rats were parasitised by lice, mites, cestodes and nematodes with mites (Androlaelaps sp. and cestodes (Mathevotaenia sp. being the dominant ecto- and endoparasites, respectively. Sex and reproductive status contributed little to the observed parasite prevalence and abundances possibly as a result of the shared burrow system. Clear seasonal patterns of parasite prevalence and abundance emerged with peaks in summer for mites and in winter for cestodes. Group size correlated negatively with mite abundance while it had no effect on cestode burdens and group membership affected infestation with both parasites. We propose that the mode of transmission as well as social factors constrain parasite propagation generating parasite patterns deviating from those commonly predicted.

  18. Raman spectra of carbonaceous materials in a fault zone in the Longmenshan thrust belt, China; comparisons with those of sedimentary and metamorphic rocks

    Science.gov (United States)

    Kouketsu, Yui; Shimizu, Ichiko; Wang, Yu; Yao, Lu; Ma, Shengli; Shimamoto, Toshihiko

    2017-03-01

    We analyzed micro-Raman spectra of carbonaceous materials (CM) in natural and experimentally deformed fault rocks from Longmenshan fault zone that caused the 2008 Wenchuan earthquake, to characterize degree of disordering of CM in a fault zone. Raman spectral parameters for 12 samples from a fault zone in Shenxigou, Sichuan, China, all show low-grade structures with no graphite. Low crystallinity and δ13C values (-24‰ to -25‰) suggest that CM in fault zone originated from host rocks (Late Triassic Xujiahe Formation). Full width at half maximum values of main spectral bands (D1 and D2), and relative intensities of two subbands (D3 and D4) of CM were variable with sample locations. However, Raman parameters of measured fault rocks fall on established trends of graphitization in sedimentary and metamorphic rocks. An empirical geothermometer gives temperatures of 160-230 °C for fault rocks in Shenxigou, and these temperatures were lower for highly sheared gouge than those for less deformed fault breccia at inner parts of the fault zone. The lower temperature and less crystallinity of CM in gouge might have been caused by the mechanical destruction of CM by severe shearing deformation, or may be due to mixing of host rocks on the footwall. CM in gouge deformed in high-velocity experiments exhibits slight changes towards graphitization characterized by reduction of D3 and D4 intensities. Thus low crystallinity of CM in natural gouge cannot be explained by our experimental results. Graphite formation during seismic fault motion is extremely local or did not occur in the study area, and the CM crystallinity from shallow to deep fault zones may be predicted as a first approximation from the graphitization trend in sedimentary and metamorphic rocks. If that case, graphite may lower the friction of shear zones at temperatures above 300 °C, deeper than the lower part of seismogenic zone.

  19. Development of artificial soft rock

    International Nuclear Information System (INIS)

    Kishi, Kiyoshi

    1995-01-01

    When foundation base rocks are deeper than the level of installing structures or there exist weathered rocks and crushed rocks in a part of base rocks, often sound artificial base rocks are made by substituting the part with concrete. But in the construction of Kashiwazaki Kariwa Nuclear Power Station of Tokyo Electric Power Co., Inc., the foundation base rocks consist of mudstone, and the stiffness of concrete is large as compared with the surrounding base rocks. As the quality of the substituting material, the nearly same stiffness as that of the surrounding soft rocks and long term stability are suitable, and the excellent workability and economical efficiency are required, therefore, artificial soft rocks were developed. As the substituting material, the soil mortar that can obtain the physical property values in stable form, which are similar to those of Nishiyama mudstone, was selected. The mechanism of its hardening and the long term stability, and the manufacturing plant are reported. As for its application to the base rocks of Kashiwazaki Kariwa Nuclear Power Station, the verification test at the site and the application to the base rocks for No. 7 plant reactor building and other places are described. (K.I.)

  20. Radionuclide Transport in Fractured Rock: Numerical Assessment for High Level Waste Repository

    Directory of Open Access Journals (Sweden)

    Claudia Siqueira da Silveira

    2013-01-01

    Full Text Available Deep and stable geological formations with low permeability have been considered for high level waste definitive repository. A common problem is the modeling of radionuclide migration in a fractured medium. Initially, we considered a system consisting of a rock matrix with a single planar fracture in water saturated porous rock. Transport in the fracture is assumed to obey an advection-diffusion equation, while molecular diffusion is considered the dominant mechanism of transport in porous matrix. The partial differential equations describing the movement of radionuclides were discretized by finite difference methods, namely, fully explicit, fully implicit, and Crank-Nicolson schemes. The convective term was discretized by the following numerical schemes: backward differences, centered differences, and forward differences. The model was validated using an analytical solution found in the literature. Finally, we carried out a simulation with relevant spent fuel nuclide data with a system consisting of a horizontal fracture and a vertical fracture for assessing the performance of a hypothetical repository inserted into the host rock. We have analysed the bentonite expanded performance at the beginning of fracture, the quantified radionuclide released from a borehole, and an estimated effective dose to an adult, obtained from ingestion of well water during one year.