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Sample records for tuff repository phase

  1. Immersion studies on candidate container alloys for the Tuff Repository

    International Nuclear Information System (INIS)

    Beavers, J.A.; Durr, C.L.

    1991-05-01

    Cortest Columbus Technologies (CC Technologies) is investigating the long-term performance of container materials used for high-level radioactive waste packages. This information is being developed for the Nuclear Regulatory Commission to aid in their assessment of the Department of Energy's application to construct a geologic repository for disposal of high-level radioactive waste. This report summarizes the results of exposure studies performed on two copper-base and two Fe-Cr-Ni alloys in simulated Tuff Repository conditions. Testing was performed at 90 degrees C in three environments; simulated J-13 well water, and two environments that simulated the chemical effects resulting from boiling and irradiation of the groundwater. Creviced specimens and U-bends were exposed to liquid, to vapor above the condensed phase, and to alternate immersion. A rod specimen was used to monitor corrosion at the vapor-liquid interface. The specimens were evaluated by electrochemical, gravimetric, and metallographic techniques following approximately 2000 hours of exposure. Results of the exposure tests indicated that all four alloys exhibited acceptable general corrosion rates in simulated J-13 well water. These rates decreased with time. Incipient pitting was observed under deposits on Alloy 825 and pitting was observed on both Alloy CDA 102 and Alloy CDA 715 in the simulated J-13 well water. No SCC was observed in U-bend specimens of any of the alloys in simulated J-13 well water. 33 refs., 48 figs., 23 tabs

  2. Low temperature spent fuel oxidation under tuff repository conditions

    International Nuclear Information System (INIS)

    Einziger, R.E.; Woodley, R.E.

    1985-01-01

    The Nevada Nuclear Waste Storage Investigations Project is studying the suitability of tuffaceous rocks at Yucca Mountain, Nye County, Nevada, for high level waste disposal. The oxidation state of LWR spent fuel in a tuff repository may be a significant factor in determining its ability to inhibit radionuclide migration. Long term exposure at low temperatures to the moist air expected in a tuff repository is expected to increase the oxidation state of the fuel. A program is underway to determine the spent fuel oxidation mechanisms which might be active in a tuff repository. Initial work involves a series of TGA experiments to determine the effectiveness of the technique and to obtain preliminary oxidation data. Tests were run at 200 0 C and 225 0 C for as long as 720 hours. Grain boundary diffusion appears to open up a greater surface area for oxidation prior to onset of bulk diffusion. Temperature strongly influences the oxidation rates. The effect of moisture is small but readily measurable. 25 refs., 7 figs., 4 tabs

  3. Environmental effects on corrosion in the Tuff repository

    International Nuclear Information System (INIS)

    Beavers, J.A.; Thompson, N.G.

    1990-02-01

    Cortest Columbus is investigating the long-term performance of container materials used for high-level waste packages as part of the information needed by the Nuclear Regulatory Commission to assess the Department of Energy's application to construct a geologic repository for high-level radioactive waste. The scope of work consists of employing short-term techniques, to examine a wide range of possible failure modes. Long-term tests are being used to verify and further examine specific failure modes identified as important by the short-term studies. The original focus of the program was on the salt repository but the emphasis was shifted to the Tuff repository. This report summarizes the results of a literature survey performed under Task 1 of the program. The survey focuses on the influence of environmental variables on the corrosion behavior of candidate container materials for the Tuff repository. Environmental variables considered include: radiation, thermal and microbial effects. 80 refs., 44 figs., 44 tabs

  4. Repository site data report for unsaturated tuff, Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Tien, P.L.; Updegraff, C.D.; Siegel, M.D.; Wahi, K.K.; Guzowski, R.V.

    1985-11-01

    The US Department of Energy is currently considering the thick sequences of unsaturated, fractured tuff at Yucca Mountain, on the southwestern boundary of the Nevada Test Site, as a possible candidate host rock for a nuclear-waste repository. Yucca Mountain is in one of the most arid areas in the United States. The site is within the south-central part of the Great Basin section of the Basin and Range physiographic province and is located near a number of silicic calderas of Tertiary age. Although localized zones of seismic activity are common throughout the province, and faults are present at Yucca Mountain, the site itself is basically aseismic. No data are available on the composition of ground water in the unsaturated zone at Yucca Mountain. It has been suggested that the composition is bounded by the compositions of water from wells USW-H3, UE25p-1, J-13, and snow or rain. There are relatively few data available from Yucca Mountain on the moisture content and saturation, hydraulic conductivity, and characteristic curves of the unsaturated zone. The available literature on thermomechanical properties of tuff does not always distinguish between data from the saturated zone and data from the unsaturated zone. Geochemical, hydrologic, and thermomechanical data available on the unsaturated tuffs of Yucca Mountain are tabulated in this report. Where the data are very sparse, they have been supplemented by data from the saturated zone or from areas other than Yucca Mountain. 316 refs., 58 figs., 37 tabs.

  5. Repository site data report for unsaturated tuff, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Tien, P.L.; Updegraff, C.D.; Siegel, M.D.; Wahi, K.K.; Guzowski, R.V.

    1985-11-01

    The US Department of Energy is currently considering the thick sequences of unsaturated, fractured tuff at Yucca Mountain, on the southwestern boundary of the Nevada Test Site, as a possible candidate host rock for a nuclear-waste repository. Yucca Mountain is in one of the most arid areas in the United States. The site is within the south-central part of the Great Basin section of the Basin and Range physiographic province and is located near a number of silicic calderas of Tertiary age. Although localized zones of seismic activity are common throughout the province, and faults are present at Yucca Mountain, the site itself is basically aseismic. No data are available on the composition of ground water in the unsaturated zone at Yucca Mountain. It has been suggested that the composition is bounded by the compositions of water from wells USW-H3, UE25p-1, J-13, and snow or rain. There are relatively few data available from Yucca Mountain on the moisture content and saturation, hydraulic conductivity, and characteristic curves of the unsaturated zone. The available literature on thermomechanical properties of tuff does not always distinguish between data from the saturated zone and data from the unsaturated zone. Geochemical, hydrologic, and thermomechanical data available on the unsaturated tuffs of Yucca Mountain are tabulated in this report. Where the data are very sparse, they have been supplemented by data from the saturated zone or from areas other than Yucca Mountain. 316 refs., 58 figs., 37 tabs

  6. The influence of copper on zircaloy spent fuel cladding degradation under a potential tuff repository condition

    International Nuclear Information System (INIS)

    Smith, H.D.

    1987-01-01

    The purpose of this paper is to report the results of an experiment designed to detect the influence of copper on zircaloy spent fuel cladding degradation in a tuff repository environment. The results show that there are no indications of discrete copper-containing phases forming as part of a developing oxide film on the zircaloy and that it is estimated that it would take more than 30,000 years to penetrate the cladding by oxidation. Both metallography and the scanning electron microscope suggest that the effects of corrosion due to exposure to the model repository environment are not significant

  7. Chemistry of diagenetically altered tuffs at a potential nuclear waste repository, Yucca Mountain, Nye County, Nevada

    International Nuclear Information System (INIS)

    Broxton, D.E.; Warren, R.G.; Hagan, R.C.; Luedemann, G.

    1986-10-01

    The chemistry of diagenetically altered tuffs at a potential nuclear waste repository, Yucca Mountain, Nevada is described. These tuffs contain substantial amounts of zeolites that are highly sorptive of certain radionuclides. Because of their widespread distribution, the zeolitic tuffs could provide important barriers to radionuclide migration. Physical properties of these tuffs and of their constituent zeolites are influenced by their chemical compositions. This study defines the amount of chemical variability within diagenetically altered tuffs and within diagenetic minerals at Yucca Mountain. Zeolitic tuffs at Yucca Mountain formed by diagenetic alteration of rhyolitic vitric tuffs. Despite their similar starting compositions, these tuffs developed compositions that vary both vertically and laterally. Widespread chemical variations were the result of open-system chemical diagenesis in which chemical components of the tuffs were mobilized and redistributed by groundwaters. Alkalies, alkaline earths, and silica were the most mobile elements during diagenesis. The zeolitic tuffs can be divided into three compositional groups: (1) calcium- and magnesium-rich tuffs associated with relatively thin zones of alteration in the unsaturated zone; (2) tuffs in thick zones of alteration at and below the water table that grade laterally from sodic compositions on the western side of Yucca Mountain to calcic compositions on the eastern side; and (3) potassic tuffs at the north end of Yucca Mountain. Physical properties of tuffs and their consistuent zeolites at Yucca Mountain may be affected by variations in compositions. Properties important for assessment of repository performance include behavior and ion exchange

  8. Preliminary drift design analyses for nuclear waste repository in tuff

    International Nuclear Information System (INIS)

    Hardy, M.P.; Brechtel, C.E.; Goodrich, R.R.; Bauer, S.J.

    1990-01-01

    The Yucca Mountain Project (YMP) is examining the feasibility of siting a repository for high-level nuclear waste at Yucca Mountain, on and adjacent to the Nevada Test Site (NTS). The proposed repository will be excavated in the Topopah Spring Member, which is a moderately fractured, unsaturated, welded tuff. Excavation stability will be required during construction, waste emplacement, retrieval (if required), and closure to ensure worker safety. The subsurface excavations will be subject to stress changes resulting from thermal expansion of the rock mass and seismic events associated with regional tectonic activity and underground nuclear explosions (UNEs). Analyses of drift stability are required to assess the acceptable waste emplacement density, to design the drift shapes and ground support systems, and to establish schedules and cost of construction. This paper outlines the proposed methodology to assess drift stability and then focuses on an example of its application to the YMP repository drifts based on preliminary site data. Because site characterization activities have not begun, the database currently lacks the extensive site-specific field and laboratory data needed to form conclusions as to the final ground support requirements. This drift design methodology will be applied and refined as more site-specific data are generated and as analytical techniques and methodologies are verified during the site characterization process

  9. Predicting spent fuel oxidation states in a tuff repository

    International Nuclear Information System (INIS)

    Einziger, R.E.; Woodley, R.E.

    1987-01-01

    Nevada Nuclear Waste Storage Investigations Project (NNWSI) is studying the suitability of the tuffaceous rocks at Yucca Mountain as a waste repository for spent fuel disposal. The oxidation state of the LWR spent fuel in the moist air environment of a tuff repository could be a significant factor in determining its leaching and dissolution characteristics. Predictions as to which oxidation states would be present are important in analyzing such a repository and thus the present study was undertaken. A set of TGA (thermogravimetric analysis) tests were conducted on well-controlled samples of irradiated PWR fuel with time and temperature as the only variables. The tests were conducted between 140 and 225 0 C for a duration up to 2200 hours. The weight gain curves were analyzed in terms of diffusion through a layer of U 3 O 7 , diffusion into the grains to form a solid solution, a simplified empirical representation of a combination of grain boundary diffusion and bulk grain oxidation. Reaction rate constants were determined in each case, but analysis of these data could not establish a definitive mechanism. 21 refs., 10 figs., 3 tabs

  10. Summary of the mineralogy-petrology of tuffs of Yucca Mountain and the secondary-phase thermal stability in tuffs

    Energy Technology Data Exchange (ETDEWEB)

    Bish, D.L.; Vaniman, D.T.; Byers, F.M. Jr.; Broxton, D.E.

    1982-11-01

    Yucca Mountain is composed of a thick sequence of silicic tuffs that are quite variable in degree of welding, alteration, and zeolitization. Tuff units above the water table are commonly devitrified or still vitric, with the exception of the zeolitized Pah Canyon Member in USW-G2. The devitrified tuffs above the water table commonly contain alkali feldspar, quartz, tridymite, and cristobalite, with minor smectite. The vitric tuffs are partly to wholly altered to sodium-calcium-saturated smectite. Below the water table are generally densely welded nonzeolitized tuffs and less densely welded zeolite-containing tuffs. The specific mineral assemblage present in Yucca Mountain tuffs has important implications in choosing a repository. The secondary phases clinoptilolite, mordenite, and smectite are very important because of their large cation sorption capacities. However, whereas densely welded tuffs containing no zeolite or glass are resistant to heating and do not dehydrate significantly, zeolitized, vitric, and smectite-containing horizons are very sensitive to minor increases in temperature. Smectites are particularly sensitive to changes in water vapor pressure and temperature, and temperature increases can lead to water evolution and large volume reductions. Similarly, clinoptilolite and mordenite begin to dehydrate below 100{sup 0}C, resulting in volume decreases. The exact effect of temperature on vitric tuffs is unclear. Under hydrothermal conditions the smectites gradually transform to nonexpanding, low sorption capacity illites, and there is evidence that this reaction has occurred in the deeper portions of USW-G2. Clinoptilolite transforms under hydrothermal conditions to analcime plus quartz with a concomitant volume decrease and water evolution. Again, there is evidence of this reaction occurring in Yucca Mountain tuffs at 80 to 100{sup 0}C.

  11. Some geochemical considerations for a potential repository site in tuff at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Erdal, B.R.; Bish, D.L.; Crowe, B.M.; Daniels, W.R.; Ogard, A.E.; Rundberg, R.S.; Vaniman, D.T.; Wolfsberg, K.

    1982-01-01

    The Nevada Nuclear Waste Storage Investigations, which is evaluating potential locations for a high-level waste repository at the Nevada Test Site and environs, is currently focusing its investigations on tuff, principally in Yucca Mountain, as a host rock. This paper discusses some of the geochemical investigations. Particular emphasis is placed on definition of some basic elements and necessary technical approaches for the geochemistry data acquisition and modeling program. Some site-specific tuff geochemical information that is important for site selection and repository performance will be identified and the current status of knowledge will then be discussed

  12. Closure development for high-level nuclear waste containers for the tuff repository

    International Nuclear Information System (INIS)

    Robitz, E.S. Jr.; McAninch, M.D. Jr.; Edmonds, D.P.; Babcock and Wilcox Co., Alliance, OH

    1990-09-01

    This report summarizes Phase 1 activities for closure development of the high-level nuclear waste package task for the tuff repository. Work was conducted under U.S. Department of Energy (DOE) Contract 9172105, administered through the Lawrence Livermore National Laboratory (LLNL), as part of the Yucca Mountain Project (YMP), funded through the DOE Office of Civilian Radioactive Waste Management (OCRWM). The goal of this phase was to select five closure processes for further evaluation in later phases of the program. A decision tree methodology was utilized to perform an objective evaluation of 15 potential closure processes. Information was gathered via a literature survey, industrial contacts, and discussions with project team members, other experts in the field, and the LLNL waste package task staff. The five processes selected were friction welding, electron beam welding, laser beam welding, gas tungsten arc welding, and plasma arc welding. These are felt to represent the best combination of weldment material properties and process performance in a remote, radioactive environment. Conceptual designs have been generated for these processes to illustrate how they would be implemented in practice. Homopolar resistance welding was included in the Phase 1 analysis, and developments in this process will be monitored via literature in Phases 2 and 3. Work was conducted in accordance with the YMP Quality Assurance Program. 223 refs., 20 figs., 9 tabs

  13. Zircaloy cladding corrosion degradation in a Tuff repository: initial experimental plan

    International Nuclear Information System (INIS)

    Smith, H.D.

    1984-07-01

    The projected environmental history of a Tuff repository sited in an unsaturated hydrologic setting is evaluated to identify the potentially most severe corrosion conditions for Zircaloy spent fuel cladding. Three distinct corrosion periods are identified over the projected history. In two of those, liquid water may be present which is believed to produce the most severe corrosive environment for Zircaloy spent fuel cladding. In the time interval 100 to 1000 years after emplacement in the repository, the most severe condition is exposure to 170 0 C water at about 100 psi in an unbreached canister. This condition will be reproduced experimentally in an autoclave. For times after 1000 years, the most severe condition is exposure to 90 0 C water that is equilibrated with the tuff and invades breached canisters. This condition will be reproduced with a water bath system

  14. Preliminary calculations of release rates from spent fuel in a tuff repository

    International Nuclear Information System (INIS)

    Apted, M.J.; O'Connell, W.J.; Lee, K.H.; MacIntyre, A.T.; Ueng, T.S.; Pigford, T.H.; Lee, W.W.L.

    1991-01-01

    Time-dependent release rates of Tc-99, I-129, Cs-135, and Np-237 have been calculated for wet-drip and moist-continuous release modes from the engineered barrier system of a potential nuclear waste repository in unsaturated tuff, representative of a possible repository at Yucca Mountain in southern Nevada. We describe the modes of water contact and of release of dissolved radionuclides to the surrounding intact rock, and the corresponding calculational models. We list the parameter values adopted, and then present numerical results, conclusions, and recommendations. 21 refs., 5 figs., 2 tabs

  15. The influence of copper on Zircaloy spent fuel cladding degradation under a potential tuff repository condition

    International Nuclear Information System (INIS)

    Smith, H.D.

    1987-03-01

    This paper reports the results of an experiment designed to detect the influence of copper on Zircaloy spent fuel cladding degradation in one possible repository environment. Copper and copper alloys are being considered for use in a tuff repository. The compatibility of a copper waste package container and the Zircaloy cladding on spent fuel has been questioned essentially because copper ion has been observed to accelerate zirconium alloy corrosion in acid environments, as does ferric iron, and a phenomenon called ''crud-induced localized corrosion'' is observed in some Boiling Water Reactors where thorugh-the-wall corrosion pits develop beneath copper-rich crud deposits. 16 refs., 6 figs., 2 tabs

  16. Studies of ancient concrete as analogs of cementitious sealing materials for a repository in tuff

    Energy Technology Data Exchange (ETDEWEB)

    Roy, D.M.; Langton, C.A.

    1989-03-01

    The durability of ancient cementitious materials has been investigated to provide data applicable to determining the resistance to weathering of concrete materials for sealing a repository for storage of high-level radioactive waste. Because tuff and volcanic ash are used in the concretes in the vicinity of Rome, the results are especially applicable to a waste repository in tuff. Ancient mortars, plasters, and concretes collected from Rome, Ostia, and Cosa dating to the third century BC show remarkable durability. The aggregates used in the mortars, plasters, and concretes included basic volcanic and pyroclastic rocks (including tuff), terra-cotta, carbonates, sands, and volcanic ash. The matrices of ancient cementitious materials have been characterized and classified into four categories: (1) hydraulic hydrated lime and hydrated lime cements, (2) hydraulic aluminous and ferruginous hydrated lime cements ({plus_minus} siliceous components), (3) pozzolana/hydrated lime cements, and (4) gypsum cements. Most of the materials investigated are in category (3). The materials were characterized to elucidate aspects of the technology that produced them and their response to the environmental exposure throughout their centuries of existence. Their remarkable properties are the result of a combination of chemical, mineralogical, and microstructural factors. Their durability was found to be affected by the matrix mineralogy, particle size, and porosity; aggregate type, grading and proportioning; and the methodology of placement. 30 refs.

  17. Carbon-14 in waste packages for spent fuel in a tuff repository

    International Nuclear Information System (INIS)

    Van Konynenburg, R.A.; Smith, C.F.; Culham, H.W.; Smith, H.D.

    1986-01-01

    Carbon-14 is produced naturally by cosmic ray neutrons in the upper atmosphere. It is also produced in nuclear reactors, in amounts much smaller than the global inventory. About one-third of this is released directly to the atmosphere, and the other two-thirds remains in the spent fuel. Both the Environmental Protection Agency and the Nuclear Regulatory Commission have established limits on release of the 14 C in spent fuel. This is of particular concern for the proposed repository in tuff, because of the unsaturated conditions and the consequent possibility of gaseous transport of 14 C as CO 2 . Existing measurements and calculations of the 14 C inventory in spent fuel are reviewed. The physical distribution and chemical forms of the 14 C are discussed. Available data on the release of 14 C from spent fuel in aqueous solutions and in gaseous environments of air, nitrogen, and helium are reviewed. Projected 14 C behavior in a tuff repository is described. It is concluded that 14 C release measurements from spent fuel into moist air at temperatures both above and below the in situ boiling point of water as well as detailed transport calculations for the tuff geological environment will be needed to determine whether the 10CFR60 and 40CFR191 requirements can be met. 56 refs., 1 tab

  18. Stress-corrosion-cracking studies on candidate container alloys for the Tuff Repository

    International Nuclear Information System (INIS)

    Beavers, J.A.; Durr, C.L.

    1992-05-01

    Cortest Columbus Technologies, Inc. (CC Technologies) investigated the long-term performance of container materials used for high-level waste package as part of the information needed by the Nuclear Regulatory Commission (NRC) to assess the Department of Energy's application to construct to geologic repository for high-level radioactive waste. At the direction of the NRC, the program focused on the Tuff Repository. This report summarizes the results of Stress-Corrosion-Cracking (SCC) studies performed in Tasks 3, 5, and 7 of the program. Two test techniques were used; U-bend exposures and Slow-Strain-Rate (SSR) tests. The testing was performed on two copper-base alloys (Alloy CDA 102 and Alloy CDA 175) and two Fe-Cr-Ni alloys (Alloy 304L and Alloy 825) in simulated J-13 groundwater and other simulated solutions for the Tuff Repository. These solutions were designed to simulate the effects of concentration and irradiation on the groundwater composition. All SCC testing on the Fe-Cr-Ni Alloys was performed on solution-annealed specimens and thus issues such as the effect of sensitization on SCC were not addressed

  19. Clinoptilolite compositions in diagenetically-altered tuffs at a potential nuclear waste repository, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Broxton, D.E.

    1987-01-01

    The compositions of Yucca Mountain clinoptilolites and their host tuffs are highly variable. Clinoptilolites and heulandites in fractures near the repository and in a thin, altered zone at the top of the Topopah Spring basal vitrophyre have consistent calcium-rich compositions. Below this level, clinoptilolites in thick zones of diagenetic alteration on the east side of Yucca Mountain have calcic-potassic compositions and become more calcium rich with depth. Clinoptilolites in stratigraphically equivalent tuffs to the west have sodic-potassic compositions and become more sodic with depth. Clinoptilolite properties important for repository performance assessment include thermal expansion/contraction behavior, hydration/dehydration behavior, and ion-exchange properties. These properties can be significantly affected by clinoptilolite compositions. The compositional variations for clinoptilolites found by this study suggest that the properties will vary vertically and laterally at Yucca Mountain. Used in conjunction with experimental data, the clinoptilolite compositions presented here can be used to model the behavior of clinoptilolites in the repository environment and along transport pathways

  20. First phase of small diameter heater experiments in tuff

    International Nuclear Information System (INIS)

    Zimmerman, R.M.

    1983-01-01

    As part of the Nevada Nuclear Waste Storage Investigations (NNWSI) project, we have undertaken small diameter heater experiments in the G-Tunnel Underground Facility on the Nevada Test Site (NTS). These experiments are to evaluate the thermal and hydrothermal behavior which might be encountered if heat producing nuclear waste were disposed of in welded and nonwelded tuffs. The two Phase I experiments discussed have focused on vertical borehole emplacements. In each experiment, temperatures were measured along the surface of the 10.2-cm-dia heater and the 12.7-cm-dia boreholes. For each experiment, measurements were compared with computer model representations. Maximum temperatures reached were: 196 0 C for the welded tuff after 21 days of operations at 800W and 173 0 C for the nonwelded tuff after 35 days of operations at 500W. Computed results indicate that the same heat transfer model (includes conduction and radiation only) can describe the behavior of both tuffs using empirical techniques to describe pore water vaporization. Hydrothermal measurements revealed heat-indiced water migration. Results indicated that small amounts of liquid water migrated into the welded tuff borehole early in the heating period. Once the rock-wall temperatures exceeded 94 0 C, in both tuffs, there was mass transport of water vapor as evidence indicated condensation cooler regions. Borehole pressures remained essentially ambient during the thermal periods

  1. Thermo-mechanical scoping calculations for a high level nuclear waste repository in tuff

    International Nuclear Information System (INIS)

    Johnson, R.L.

    1981-06-01

    Thermal and mechanical stress scoping calculations have been completed for a high level nuclear waste repository sited in welded tuff below the water table at the Nevada Test Site. Reported are the results of the studies performed at Sandia National Laboratories. A ubiquitous jointed rock model which allows slip along randomly oriented joints and subsequent stress redistribution due to slip and fracture of intact rock was used to model the rock mass. Computations were made for two power input levels and for conditions of boiling of the groundwater at 100 0 C and for no boiling of the groundwater

  2. Uncertainties in sealing a nuclear waste repository in partially saturated tuff

    International Nuclear Information System (INIS)

    Tillerson, J.R.; Fernandez, J.A.; Hinkebein, T.E.

    1989-01-01

    Sealing a nuclear waste repository in partially saturated tuff presents unique challenges to assuring performance of sealing components. Design and performance of components for sealing shafts, ramps, drifts, and exploratory boreholes depend on specific features of both the repository design and the site; of particular importance is the hydrologic environment in the unsaturated zone, including the role of fracture flow. Repository design features important to sealing of a repository include the size and location of shaft and ramp accesses, excavation methods, and the underground layout features such as grade (drainage direction) and location relative to geologic structure. Uncertainties about seal components relate to the postclosure environment for the seals, the emplacement methods, the material properties, and the potential performance of the components. An approach has been developed to reduce uncertainties and to increase confidence in seal performance; it includes gathering extensive site characterization data, establishing conservative design requirements, testing seal components in laboratory and field environments, and refining designs of both the seals and the repository before seals are installed. 9 refs., 5 figs., 2 tabs

  3. Conceptualization of a hypothetical high-level nuclear waste repository site in unsaturated, fractured tuff

    International Nuclear Information System (INIS)

    Parsons, A.M.; Olague, N.E.; Gallegos, D.P.

    1991-01-01

    Under the sponsorship of the US Nuclear Regulatory Commission (NRC), Sandia National Laboratories (SNL) is developing a performance assessment methodology for the analysis of long-term disposal and isolation of high-level nuclear wastes (HLW) in alternative geologic media. As part of this exercise, SNL created a conceptualization of ground-water flow and radionuclide transport in the far field of a hypothetical HLW repository site located in unsaturated, fractured tuff formations. This study provides a foundation for the development of conceptual mathematical, and numerical models to be used in this performance assessment methodology. This conceptualization is site specific in terms of geometry, the regional ground-water flow system, stratigraphy, and structure in that these are based on information from Yucca Mountain located on the Nevada Test Site. However, in terms of processes in unsaturated, fractured, porous media, the model is generic. This report also provides a review and evaluation of previously proposed conceptual models of unsaturated and saturated flow and solute transport. This report provides a qualitative description of a hypothetical HLW repository site in fractured tuff. However, evaluation of the current knowledge of flow and transport at Yucca Mountain does not yield a single conceptual model. Instead, multiple conceptual models are possible given the existing information

  4. Geotechnical instrumentation requirements for atdepth testing and repository monitoring in tuff

    International Nuclear Information System (INIS)

    Zimmerman, R.M.

    1983-01-01

    This paper outlines geotechnical instrumentation requirements for the possible establishment of a nuclear waste repository in tuff on the Nevada Test Site (NTS). The Nuclear Regulatory Commission (NRC) has specified a continuing program to confirm performance during the operational period of the repository, which could last 50 years. Minimum required geotechnical measurements for confirmation of performance include thermal and thermomechanical responses; changes in stress, strain, and displacements; and pore pressure and groundwater flow characteristics. Conditions expected in tuff are: maximum rock temperatures of less than 250 0 C, stresses less than 100 MPa, strains between + or -0.01 mm/mm, and pore pressures less than 35 KPa in the unsaturated zone where hydraulic head is not the primary contributor. The paper describes instrumentation needed to make the desired measurements. In general, the instrumentation and data system are required to be stable and reliable for tens of years. Designs must consider requirements for temperature stability, temperature expansion compensation, moisture resistance, and long-term durability in mining-type environments. Severe requirements such as these suggest consideration of techniques for in-situ replacement of instrumentation. State-of-the-art instrumentation is briefly described along with a discussion of needs for refinement, replacement/recalibration and instrumentation development

  5. Natural alteration in the cooling Topopah Spring tuff, Yucca Mountain, Nevada, as an analog to a waste-repository hydrothermal regime

    Energy Technology Data Exchange (ETDEWEB)

    Levy, S.; Valentine, G.

    1993-11-01

    Studies of natural hydrothermal alteration in the cooling Topopah Spring tuff suggest a useful ``self-analog`` predictor of fluid-rock interactions within the thermal regime imposed by a potential nuclear waste repository at Yucca Mountain. This tuff has the advantages of representative rock types and appropriate spatial distribution of lithologic features. The cooling history of the tuff spanned the temperature range for any proposed repository thermal load, and the unsaturated-zone hydrologic conditions of the natural alteration would have been similar to existing conditions. A site at northeastern Yucca Mountain, with a prominent vertical fracture zone, has been selected for natural analog studies. The cooling of the tuff and the movement of water in the fracture zone and adjacent matrix will be modeled with the finite element code FEHNM, capable of simulating flow through porous and fractured media using a dual porosity-dual permeability continuum model, with heat transfer and two-phase (vapor and liquid) processes fully accounted for.

  6. Natural alteration in the cooling Topopah Spring tuff, Yucca Mountain, Nevada, as an analog to a waste-repository hydrothermal regime

    International Nuclear Information System (INIS)

    Levy, S.; Valentine, G.

    1993-01-01

    Studies of natural hydrothermal alteration in the cooling Topopah Spring tuff suggest a useful ''self-analog'' predictor of fluid-rock interactions within the thermal regime imposed by a potential nuclear waste repository at Yucca Mountain. This tuff has the advantages of representative rock types and appropriate spatial distribution of lithologic features. The cooling history of the tuff spanned the temperature range for any proposed repository thermal load, and the unsaturated-zone hydrologic conditions of the natural alteration would have been similar to existing conditions. A site at northeastern Yucca Mountain, with a prominent vertical fracture zone, has been selected for natural analog studies. The cooling of the tuff and the movement of water in the fracture zone and adjacent matrix will be modeled with the finite element code FEHNM, capable of simulating flow through porous and fractured media using a dual porosity-dual permeability continuum model, with heat transfer and two-phase (vapor and liquid) processes fully accounted for

  7. Methodology for determining time-dependent mechanical properties of tuff subjected to near-field repository conditions

    International Nuclear Information System (INIS)

    Blacic, J.D.; Andersen, R.

    1983-01-01

    We have established a methodology to determine the time dependence of strength and transport properties of tuff under conditions appropriate to a nuclear waste repository. Exploratory tests to determine the approximate magnitudes of thermomechanical property changes are nearly complete. In this report we describe the capabilities of an apparatus designed to precisely measure the time-dependent deformation and permeability of tuff at simulated repository conditions. Preliminary tests with this new apparatus indicate that microclastic creep failure of tuff occurs over a narrow strain range with little precursory Tertiary creep behavior. In one test, deformation under conditions of slowly decreasing effective pressure resulted in failure, whereas some strain indicators showed a decreasing rate of strain

  8. Containment barrier metals for high-level waste packages in a Tuff repository

    Energy Technology Data Exchange (ETDEWEB)

    Russell, E.W.; McCright, R.D.; O`Neal, W.C.

    1983-10-12

    The Nevada Nuclear Waste Storage Investigations (NNWSI) Waste Package project is part of the US Department of Energy`s Civilian Radioactive Waste Management (CRWM) Program. The NNWSI project is working towards the development of multibarriered packages for the disposal of spent fuel and high-level waste in tuff in the unsaturated zone at Yucca Mountain at the Nevada Test Site (NTS). The final engineered barrier system design may be composed of a waste form, canister, overpack, borehole liner, packing, and the near field host rock, or some combination thereof. Lawrence Livermore National Laboratory`s (LLNL) role is to design, model, and test the waste package subsystem for the tuff repository. At the present stage of development of the nuclear waste management program at LLNL, the detailed requirements for the waste package design are not yet firmly established. In spite of these uncertainties as to the detailed package requirements, we have begun the conceptual design stage. By conceptual design, we mean design based on our best assessment of present and future regulatory requirements. We anticipate that changes will occur as the detailed requirements for waste package design are finalized. 17 references, 4 figures, 10 tables.

  9. Potentiodynamic polarization studies on candidate container alloys for the Tuff Repository

    International Nuclear Information System (INIS)

    Thompson, N.G.; Beavers, J.A.; Durr, C.L.

    1992-01-01

    Cortest Columbus Technologies, Inc. (CC Technologies) is investigating the long-term performance of container materials used for high-level radioactive waste packages. This information is being developed for the Nuclear Regulatory Commission to aid in their assessment of the Department of Energy's application to construct a geologic repository for disposal of high-level radioactive waste. This report summarizes the results of cyclic-potentiodynamic-polarization (CCP) studies performed on candidate container materials for the Tuff Repository. The CPP technique was used to provide an understanding of how specific variables such as environmental composition, temperature, alloy composition, and welding affect both the general- and localized-corrosion behavior of two copper-base and two Fe-Cr-Ni alloys in simulated repository environments. A statistically-designed test solution matrix was formulated, based on an extensive search of the literature, to evaluate the possible range of environmental species that may occur in the repository over the life of the canister. Forty-two CPP curves were performed with each alloy and the results indicated that several different types of corrosion were possible. The copper-base alloys exhibited unusual CCP behavior in that hysteresis was not always associated with pitting. The effects of temperature on the corrosions behavior were evaluated in two types of tests; isothermal tests at temperatures from 50 degrees C to 90 degrees C and heat-transfer tests where the solution was maintained at 50 degrees C and the specimen was internally heated to 90 degrees C. In the isothermal test, CPP curves were obtained with each alloy in simulated environments at 50 degrees C, 75 degrees C, and 90 degrees C. The results of these CCP experiments indicated that no systematic trends were evident for the environments tested. Lastly, the effects of welding on the corrosion behavior of the alloys in simulated environments were examined

  10. Radionuclide release from PWR fuels in a reference tuff repository groundwater

    International Nuclear Information System (INIS)

    Wilson, C.N.; Oversby, V.M.

    1985-03-01

    The Nevada Nuclear Waste Storage Investigations Project (NNWSI) is studying the suitability of the welded devitrified Topopah Spring tuff at Yucca Mountain, Nye County, Nevada, for potential use as a high-level nuclear waste repository. In support of the Waste Package task of NNWSI, tests have been conducted under ambient air environment to measure radionuclide release from two pressurized water reactor (PWR) spent fuels in water obtained from the J-13 well near the Yucca Mountain site. Four specimen types, representing a range of fuel physical conditions that may exist in a failed waste canister containing a limited amount of water were tested. The specimen types were: fuel rod sections split open to expose bare fuel particles; rod sections with water-tight end fittings with a 2.5-cm long by 150-μm wide slit through the cladding; rod sections with water-tight end fittings and two 200-μm-diameter holes through the cladding; and undefected rod segments with water-tight end fittings. Radionuclide release results from the first 223-day test runs on H.B. Robinson spent fuel specimens in J-13 water are reported and compared to results from a previous test series in which similar Turkey Point reactor spent fuel specimens were tested on deionized water. Selected initial results are also given for Turkey Point fuel specimens tested on J-13 water. Results suggest that the actinides Pu, Am, Cm and Np are released congruently with U as the UO 2 spent fuel matrix dissolves. Fractional release of 137 Cs and 99 Tc was greater than that measured for the actinides. Generally, lower radionuclide releases were measured for the H.B. Robinson fuel in J-13 water than for Turkey Point Fuel in deionized water. 8 references, 7 figures, 9 tables

  11. Effects of long-term exposure of tuffs to high-level nuclear waste-repository conditions. Preliminary report

    International Nuclear Information System (INIS)

    Blacic, J.; Carter, J.; Halleck, P.; Johnson, P.; Shankland, T.; Andersen, R.; Spicochi, K.; Heller, A.

    1982-02-01

    Tests have been performed to explore the effects of extended exposure of tuffs from the southwestern portion of the Nevada Test Site to temperatures and pressures similar to those that will be encountered in a high-level nuclear waste repository. Tuff samples ranging from highly welded, nonzeolitized to unwelded, highly zeolitized varieties were subjected to temperatures of 80, 120, and 180 0 C; confining pressures of 9.7 and 19.7 MPa; and water-pore pressures of 0.5 to 19.7 MPa for durations of 2 to 6 months. The following basic properties were measured before and after exposure and compared: tensile strength, uniaxial compressive strength, grain density, porosity, mineralogy, permeability, thermal expansion, and thermal conductivity. Depending on rock type and exposure conditions, significant changes in ambient tensile strength, compressive strength, grain density, and porosity were measured. Mineralogic examination, permeability, and thermal property measurements remain to be completed

  12. Vacuum drilling of unsaturated tuffs at a potential radioactive-waste repository, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Whitfield, M.S.

    1985-01-01

    A vacuum reverse-air circulation drilling method was used to drill two 17-1/2-inch (44.5-centimeter) diameter test holes to depths of 1269 feet (387 meters) and 1887 feet (575 meters) at Yucca Mountain near the Nevada Test Site. The site is being considered by the US Department of Energy for construction of a high-level radioactive-waste repository. One of these two test holes (USW UZ-1) has been equipped with instrumentation to obtain a long-term record of pressure and moisture potential data; the other test hole (USW UZ-6) will be similarly instrumented in the near future. These investigations are being conducted as part of the Nevada Nuclear Waste Storage Investigations Project of the US Department of Energy. The test holes were drilled using a 5-1/2-inch (14-centimeter) by 8-5/8-inch (22-centimeter) dual-string reverse-vacuum assembly. A vacuum, induced at the land surface, removed the drill cuttings through the inner string. Compressed air was injected into the dual-string annulus to cool the bit and to keep the bit and inner string clean. A tracer gas, sulfur hexafluoride (SF 6 ), was added to the compressed air for a later determination of atmospheric contamination that might have occurred during the drilling. After reaching the surface, the drill cuttings were routed to a dry separator for sample collection. Then return air and dust from the cuttings were routed to a wet separator where the dust was removed by a water spray, and the remaining air was exhausted through the vacuum unit (blower) to the atmosphere. 6 refs., 4 figs

  13. Preliminary thermal expansion screening data for tuffs

    International Nuclear Information System (INIS)

    Lappin, A.R.

    1980-03-01

    A major variable in evaluating the potential of silicic tuffs for use in geologic disposal of heat-producing nuclear wastes is thermal expansion. Results of ambient-pressure linear expansion measurements on a group of tuffs that vary treatly in porosity and mineralogy are presente here. Thermal expansion of devitrified welded tuffs is generally linear with increasing temperature and independent of both porosity and heating rate. Mineralogic factors affecting behavior of these tuffs are limited to the presence or absence of cristobalite and altered biotite. The presence of cristobalite results in markedly nonlinear expansion above 200 0 C. If biotite in biotite-hearing rocks alters even slightly to expandable clays, the behavior of these tuffs near the boiling point of water can be dominated by contraction of the expandable phase. Expansion of both high- and low-porosity tuffs containing hydrated silicic glass and/or expandable clays is complex. The behavior of these rocks appears to be completely dominated by dehydration of hydrous phases and, hence, should be critically dependent on fluid pressure. Valid extrapolation of the ambient-pressure results presented here to depths of interest for construction of a nuclear-waste repository will depend on a good understanding of the interaction of dehydration rates and fluid pressures, and of the effects of both micro- and macrofractures on the response of tuff masss

  14. Fabrication development for high-level nuclear waste containers for the tuff repository

    International Nuclear Information System (INIS)

    Domian, H.A.; Holbrook, R.L.; LaCount, D.F.; Babcock and Wilcox Co., Alliance, OH

    1990-09-01

    This final report completes Phase 1 of an engineering study of potential manufacturing processes for the fabrication of containers for the long-term storage of nuclear waste. An extensive literature and industry review was conducted to identify and characterize various processes. A technical specification was prepared using the American Society of Mechanical Engineers Boiler ampersand Pressure Vessel Code (ASME BPVC) to develop the requirements. A complex weighting and evaluation system was devised as a preliminary method to assess the processes. The system takes into account the likelihood and severity of each possible failure mechanism in service and the effects of various processes on the microstructural features. It is concluded that an integral, seamless lower unit of the container made by back extrusion has potential performance advantages but is also very high in cost. A welded construction offers lower cost and may be adequate for the application. Recommendations are made for the processes to be further evaluated in the next phase when mock-up trials will be conducted to address key concerns with various processes and materials before selecting a primary manufacturing process. 43 refs., 26 figs., 34 tabs

  15. Background studies in support of a feasibility assessment on the use of copper-base materials for nuclear waste packages in a repository in tuff

    International Nuclear Information System (INIS)

    Van Konynenburg, R.A.; Kundig, K.J.A.; Lyman, W.S.; Prager, M.; Meyers, J.R.; Servi, I.S.

    1990-06-01

    This report combines six work units performed in FY'85--86 by the Copper Development Association and the International Copper Research Association under contract with the University of California. The work includes literature surveys and state-of-the-art summaries on several considerations influencing the feasibility of the use of copper-base materials for fabricating high-level nuclear waste packages for the proposed repository in tuff rock at Yucca Mountain, Nevada. The general conclusion from this work was that copper-base materials are viable candidates for inclusion in the materials selection process for this application. 55 refs., 48 figs., 22 tabs

  16. Background studies in support of a feasibility assessment on the use of copper-base materials for nuclear waste packages in a repository in tuff

    Energy Technology Data Exchange (ETDEWEB)

    Van Konynenburg, R.A. [Lawrence Livermore National Lab., CA (USA); Kundig, K.J.A.; Lyman, W.S.; Prager, M.; Meyers, J.R.; Servi, I.S. [CDA/INCRA Joint Advisory Group, Greenwich, CT (USA)

    1990-06-01

    This report combines six work units performed in FY`85--86 by the Copper Development Association and the International Copper Research Association under contract with the University of California. The work includes literature surveys and state-of-the-art summaries on several considerations influencing the feasibility of the use of copper-base materials for fabricating high-level nuclear waste packages for the proposed repository in tuff rock at Yucca Mountain, Nevada. The general conclusion from this work was that copper-base materials are viable candidates for inclusion in the materials selection process for this application. 55 refs., 48 figs., 22 tabs.

  17. Operational procedures for receiving, packaging, emplacing, and retrieving high-level and transuranic waste in a geologic repository in TUFF

    International Nuclear Information System (INIS)

    Dennis, A.W.; Mulkin, R.

    1984-01-01

    The Nevada Nuclear Waste Storage Investigations Project, directed by the Nevada Operations Office of the Department of Energy, is currently developing conceptual designs for a commercial nuclear waste repository. In this paper, the preliminary repository operating plans are identified and the proposed repository waste inventory is discussed. The receipt rates for truck and rail car shipments of waste are determined as are the required repository waste emplacement rates

  18. A review of degradation behavior of container materials for disposal of high-level nuclear waste in tuff and alternative repository environments

    International Nuclear Information System (INIS)

    Maiya, P.S.

    1989-06-01

    Corrosion resistance of materials in aqueous system is reviewed from the perspective of their suitability as container materials for nuclear waste. A discussion of the chemistry and characterization of repository environments, namely, tuff and alternative environments (shale, limestone, and carbonate), is followed by a description of corrosion mechanisms. In this review, emphasis is placed on localized corrosion (e.g., stress corrosion cracking, crevice corrosion, and pitting) because localized corrosion is difficult to account for in design of components, but it is the life-limiting factor for many metallic and nonmetallic systems. The physical metallurgy and microstructure of the potential alloys are briefly described because they provide insight into both the mechanisms of various localized corrosion processes and possible solutions to corrosion problems. A survey of localized corrosion behavior of potential candidate materials as determined by both corrosion and mechanical test in a large number of repository-related environments is presented in order to determine the most promising materials for a given environment. These studies include the effects of various environmental factors (such as pH, temperature, and electrochemical potentials), as well as alloying elements and other microstructural parameters, on corrosion. The modifications of the environment induced by gamma radiation and the stability of the microstructure under gamma irradiation are also described. Although in the majority of cases the tests and the environments used are severe, they point out that metallic materials are generally more promising than nonmetallic materials (ceramic and polymeric materials). 122 refs., 61 figs., 19 tabs

  19. Technical test description of activities to determine the potential for spent fuel oxidation in a tuff repository

    International Nuclear Information System (INIS)

    Einziger, R.E.

    1985-06-01

    The potential change in the oxidation state of spent fuel during its residence in a repository must be known to evaluate its radionuclide retention capabilities. Once the container breaches, the spent fuel in a repository sited above the water table will be exposed to a moist air atmosphere at low temperatures. Thermodynamically, there is no reason why the fuel should not oxidize to a higher oxidation state under these conditions, given enough time. Depending on the rate of oxidation, higher oxides with potentially higher leach rates may eventually form or the cladding may even split open. If either of these oxidation effects occurs, the ability of spent fuel to retard radionuclide migration will be reduced. A technical test description is presented to study spent fuel oxidation at low temperatures characteristic of the post-container breach period and at high temperatures in a moist inert atmosphere characteristic of a sealed container with waterlogged fuel, early in the repository life. The approach taken will be to perform tests and evaluations to gain understanding of the operative oxidation mechanisms, to obtain oxidation rate data, and to make projections of potential long-term fuel oxidation states. Time and temperature dependence of existing models will be evaluated, and the dependence of the model projections on fuel variables will be determined. 27 refs., 7 figs., 4 tabs

  20. Corrosion phase formation on container alloys in basalt repository environments

    International Nuclear Information System (INIS)

    Johnston, R.G.; Anantatmula, R.P.; Lutton, J.M.; Rivera, C.L.

    1986-01-01

    The Basalt Waste Isolation Project is evaluating the suitability of basalt in southeastern Washington State as a possible location for a nuclear waste repository. The performance of the waste package, which includes the waste form, container, and surrounding packing material, will be affected by the stability of container alloys in the repository environment. Primary corrosion phases and altered packing material containing metals leached from the container may also influence subsequent reactions between the waste form and repository environment. Copper- and iron-based alloys were tested at 50 0 to 300 0 C in an air/steam environment and in pressure vessels in ground-water-saturated basalt-bentonite packing material. Reaction phases formed on the alloys were identified and corrosion rates were measured. Changes in adhering packing material were also evaluated. The observed reactions and their possible effects on container alloy durability in the repository are discussed

  1. Overview of adaptive phased management repository design development

    International Nuclear Information System (INIS)

    Russell, S.

    2011-01-01

    The Nuclear Waste Management Organization is implementing Adaptive Phased Management, Canada's plan for long-term management of used nuclear fuel. The organization is proceeding with the process for selecting a site in partnership with an informed and willing host community to safely and securely container and isolate used nuclear fuel in a deep geological repository in a suitable rock formation. Adaptive Phased Management is the culmination of more than 30 years of research, development and demonstration of repository concepts in Canada. Adaptive Phased Management uses a phased and adaptive step-wise approach to the multi-barrier system which is consistent with the long-term waste management approaches being developed in many other countries with nuclear power programs such as Sweden, Finland, Switzerland, the United Kingdom and France. The Nuclear Waste Management Organization is examining and developing conceptual designs for a deep geological repository and associated facilities for the placement of used nuclear fuel in long-lived containers. This paper will examine two of these generic conceptual designs which have recently been refined and updated. These conceptual designs will be used to support a pre-project review of repository design and safety by the Canadian Nuclear Safety Commission. (author)

  2. National Geoscience Data Repository System: Phase 2 final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-01

    The American Geological Institute (AGI) has completed Phase 2 of a project to establish a National Geoscience Data Repository System (NGDRS). The project`s primary objectives are to preserve geoscience data in jeopardy of being destroyed and to make that data available to those who have a need to use it in future investigations. These data are available for donation to the public as a result of the downsizing that has occurred in the major petroleum and mining companies in the US for the past decade. In recent years, these companies have consolidated domestic operations, sold many of their domestic properties and relinquished many of their leases. The scientific data associated with those properties are no longer considered to be useful assets and are consequently in danger of being lost forever. The national repository project will make many of these data available to the geoscience community for the first time. Phase 2 encompasses the establishment of standards for indexing and cataloging of geoscience data and determination of the costs of transferring data from the private sector to public-sector data repositories. Pilot projects evaluated the feasibility of the project for transfer of different data types and creation of a Web-based metadata supercatalog and browser. Also as part of the project, a national directory of geoscience data repositories was compiled to assess what data are currently available in existing facilities. The next step, Phase 3, will focus on the initiation of transfer of geoscience data from the private sector to the public domain and development of the web-based Geotrek metadata supercatalog.

  3. The international INTRAVAL project. Phase 2, working group 1 report. Flow and tracer experiments in unsaturated tuff and soil. Las Cruces trench and Apache Leap tuff studies

    International Nuclear Information System (INIS)

    Nicholson, T.J.; Guzman-Guzman, A.; Hills, R.; Rasmussen, T.C.

    1997-01-01

    The Working Group 1 final report summaries two test case studies, the Las Cruces Trench (LCT), and Apache Leap Tuff Site (ALTS) experiments. The objectives of these two field studies were to evaluate models for water flow and contaminant transport in unsaturated, heterogeneous soils and fractured tuff. The LCT experiments were specifically designed to test various deterministic and stochastic models of water flow and solute transport in heterogeneous, unsaturated soils. Experimental data from the first tow LCT experiments, and detailed field characterisation studies provided information for developing and calibrating the models. Experimental results from the third experiment were held confidential from the modellers, and were used for model comparison. Comparative analyses included: point comparisons of water content; predicted mean behavior for water flow; point comparisons of solute concentrations; and predicted mean behavior for tritium transport. These analyses indicated that no model, whether uniform or heterogeneous, proved superior. Since the INTRAVAL study, however, a new method has been developed for conditioning the hydraulic properties used for flow and transport modelling based on the initial field-measured water content distributions and a set of scale-mean hydraulic parameters. Very good matches between the observed and simulated flow and transport behavior were obtained using the conditioning procedure, without model calibration. The ALTS experiments were designed to evaluate characterisation methods and their associated conceptual models for coupled matrix-fracture continua over a range of scales (i.e., 2.5 centimeter rock samples; 10 centimeter cores; 1 meter block; and 30 meter boreholes). Within these spatial scales, laboratory and field tests were conducted for estimating pneumatic, thermal, hydraulic, and transport property values for different conceptual models. The analyses included testing of current conceptual, mathematical and physical

  4. Major element and oxygen isotope geochemistry of vapour-phase garnet from the Topopah Spring Tuff at Yucca Mountain, Nevada, USA

    Science.gov (United States)

    Moscati, Richard J.; Johnson, Craig A.

    2014-01-01

    Twenty vapour-phase garnets were studied in two samples of the Topopah Spring Tuff of the Paintbrush Group from Yucca Mountain, in southern Nevada. The Miocene-age Topopah Spring Tuff is a 350 m thick, devitrified, moderately to densely welded ash-flow tuff that is zoned compositionally from high-silica rhyolite to latite. During cooling of the tuff, escaping vapour produced lithophysae (former gas cavities) lined with an assemblage of tridymite (commonly inverted to cristobalite or quartz), sanidine and locally, hematite and/or garnet. Vapour-phase topaz and economic deposits associated commonly with topaz-bearing rhyolites (characteristically enriched in F) were not found in the Topopah Spring Tuff at Yucca Mountain. Based on their occurrence only in lithophysae, the garnets are not primary igneous phenocrysts, but rather crystals that grew from a F-poor magma-derived vapour trapped during and after emplacement of the tuff. The garnets are euhedral, vitreous, reddish brown, trapezohedral, as large as 2 mm in diameter and fractured. The garnets also contain inclusions of tridymite. Electron microprobe analyses of the garnets reveal that they are almandine-spessartine (48.0 and 47.9 mol.%, respectively), have an average composition of (Fe1.46Mn1.45Mg0.03Ca0.10)(Al1.93Ti0.02)Si3.01O12 and are comparatively homogeneous in Fe and Mn concentrations from core to rim. Composited garnets from each sample site have δ18O values of 7.2 and 7.4‰. The associated quartz (after tridymite) has δ18O values of 17.4 and 17.6‰, values indicative of reaction with later, low-temperature water. Unaltered tridymite from higher in the stratigraphic section has a δ18O of 11.1‰ which, when coupled with the garnet δ18O values in a quartz-garnet fractionation equation, indicates isotopic equilibration (vapour-phase crystallization) at temperatures of ~600°C. This high-temperature mineralization, formed during cooling of the tuffs, is distinct from the later and commonly recognized

  5. National radioactive waste repository site selection study. Phase 2. A report on public comment

    International Nuclear Information System (INIS)

    1995-11-01

    Agreement was reached in principle between State/Territory and the Commonwealth of Australia Governments that a suitable site for a radioactive wastes repository must be found. The discussion papers resulting from the Phase 1 and Phase 2 of the site selection study were released for public comment. The national repository will be for disposal of low level and short-lived intermediate level radioactive wastes streaming from the medical, research and industrial use of radioisotopes in Australia. The purpose of this report is to summarise and respond in general terms to comment received on the discussion paper -Phase 2 of the study. Forty five submissions were received. Of these: 18 supported the Phase 2 study approach and the concept of a national repository; 13 did not state a clear position but either requested more information or provided constructive comment on the siting process; 7 supported the site selection approach and the repository concept but suggested that the repository should not be sited in a particular area; 3 opposed the siting of the repository in their vicinity but not necessarily the repository concept and site selection approach; 4 opposed the concept of a national repository. This compares with 124 submissions on Phase 1 of the study, of which 57 opposed the national repository concept (52 of these were from letters elicited by Greenpeace) and 48 supported the establishment of a national repository and the site selection approach proposed. 3 figs

  6. Impact analysis on ESF design for Calico Hills penetration and exploratory drift and tuff main extension to limits of the repository block

    International Nuclear Information System (INIS)

    Grenia, J.; Weyand, L.

    1988-01-01

    The study covers the impacts on project costs, schedule, human resources and engineering designs caused by increases in site characterization activity consisting of penetration of the Calico Hills formation by ES-1 shaft with exploratory drifting to the Ghost Dance fault and/or drifting 10,000 feet southward from the MTL ESF test complex area to the end of the future repository block

  7. An investigation of the impact of conceptual model uncertainty on the estimated performance of a hypothetical high-level nuclear waste repository site in unsaturated, fractured tuff

    International Nuclear Information System (INIS)

    Gallegos, D.P.; Phol, P.I.; Updegraff, C.D.

    1992-04-01

    Performance assessment modeling for High Level Waste (HLW) disposal incorporates three different types of uncertainty. These include data and parameter uncertainty, modeling uncertainty (which includes conceptual, mathematical, and numerical), and uncertainty associated with predicting the future state of the system. In this study, the potential impact of conceptual model uncertainty on the estimated performance of a hypothetical high-level radioactive waste disposal site in unsaturated, fractured tuff has been assessed for a given group of conceptual models. This was accomplished by taking a series of six, one-dimensional conceptual models, which differed only by the fundamental assumptions used to develop them, and conducting ground-water flow and radionuclide transport simulations. Complementary cumulative distribution functions (CCDFs) representing integrated radionuclide release to the water table indicate that differences in the basic assumptions used to develop conceptual models can have a significant impact on the estimated performance of the site. Because each of the conceptual models employed the same mathematical and numerical models, contained the same data and parameter values and ranges, and did not consider the possible future states of the system, changes in the CCDF could be attributed primarily to differences in conceptual modeling assumptions. Studies such as this one could help prioritize site characterization activities by identifying critical and uncertain assumptions used in model development, thereby providing guidance as to where reduction of uncertainty is most important

  8. Calculated compositions of porewater affected by a nuclear waste repository in a tuff geologic environment from 0 to 10,000 years

    International Nuclear Information System (INIS)

    Criscenti, L.C.; Arthur, R.C.

    1994-01-01

    Porewater compositions were estimated for an environment assuming that high-level radioactive waste has been stored for 10,000 years under geologic conditions analogous to those at the Yucca Mountain site in Nevada. The porewater compositions calculated with the EQ3/EQ6 geochemical code are intended for use in preliminary performance assessments of borosilicate glass waste packages. The porewater compositions were calculated using water-rock interaction models that are loosely coupled with two time-temperature periods in the host rocks: a cooling period between 900 years and 3,000 years after repository closure and an isothermal period from 3,000 years to 10,000 years. Significant changes in water composition are predicted to occur during the initial period of water-rock interaction; for example, the pH of the porewater increases from 6.4 to 9.1. Constant porewater compositions are predicted during the isothermal period. The results suggest that major changes in porewater composition will occur over a relatively short time frame and that these changes will persevere throughout the repository lifetime. (author) 5 figs., 3 tabs., 28 refs

  9. National Geoscience Data Repository System, Phase III: Implementation and operation of the repository

    Energy Technology Data Exchange (ETDEWEB)

    American Geological Institute

    2000-03-13

    The American Geological Institute's (AGI) National Geoscience Data Repository System (NGDRS) was initiated in response to the fact that billions of dollars worth of domestic geoscience data are in jeopardy of being irrevocably lost or destroyed as a consequence of the ongoing downsizing of the U.S. energy and minerals industry. Preservation and access to domestic geological and geophysical data are critical to the energy security and economic prosperity of the nation. There is a narrow window of opportunity to act before valuable data are destroyed. The data truly represent a national treasure and immediate steps must be taken to assure their preservation.

  10. Anisotropy of the Topopah Spring Member Tuff

    International Nuclear Information System (INIS)

    Martin, R.J. III; Boyd, P.J.; Haupt, R.W.; Price, R.H.

    1992-07-01

    Mechanical properties of the tuffaceous rocks within Yucca Mountain are needed for near and far-field modeling of the potential nuclear waste repository. If the mechanical properties are significantly anisotropic (i.e., direction-dependent), a more complex model is required. Relevant data from tuffs tested in earlier studies indicate that elastic and strength properties are anisotropic. This scoping study confirms the elastic anisotropy and concludes some tuffs are transversely isotropic. An approach for sampling and testing the rock to determine the magnitude of the anisotropy is proposed

  11. Anisotropy of the Topopah Spring Member Tuff

    Energy Technology Data Exchange (ETDEWEB)

    Martin, R.J. III; Boyd, P.J.; Haupt, R.W. [New England Research, Inc., White River Junction, VT (United States); Price, R.H. [Sandia National Labs., Albuquerque, NM (United States)

    1992-07-01

    Mechanical properties of the tuffaceous rocks within Yucca Mountain are needed for near and far-field modeling of the potential nuclear waste repository. If the mechanical properties are significantly anisotropic (i.e., direction-dependent), a more complex model is required. Relevant data from tuffs tested in earlier studies indicate that elastic and strength properties are anisotropic. This scoping study confirms the elastic anisotropy and concludes some tuffs are transversely isotropic. An approach for sampling and testing the rock to determine the magnitude of the anisotropy is proposed.

  12. Mechanical tunnel excavation in welded tuff

    International Nuclear Information System (INIS)

    Sperry, P.E.

    1991-01-01

    The Technical Review Board for the US high-level radioactive waste facility at Yucca Mountain has recommended maximum use of open-quotes the most modern mechanical excavation techniques...in order to reduce disturbance to the rock walls and to achieve greater economy of time and cost.close quotes Tunnels for the waste repository at Yucca Mountain can be economically constructed with mechanical excavation equipment. This paper presents the results of mechanical excavation of a tunnel in welded tuff, similar to the tuffs of Yucca Mountain. These results are projected to excavation of emplacement drifts in Yucca Mountain using a current state-of-the-art tunnel boring machine (TBM)

  13. Petrologic and geochemical characterization of the Bullfrog Member of the Crater Flat Tuff: outcrop samples used in waste package experiments

    International Nuclear Information System (INIS)

    Knauss, K.G.

    1983-09-01

    In support of the Waste Package Task within the Nevada Nuclear Waste Storage Investigation (NNWSI), experiments on hydrothermal rock/water interaction, corrosion, thermomechanics, and geochemical modeling calculations are being conducted. All of these activities require characterization of the initial bulk composition, mineralogy, and individual phase geochemistry of the potential repository host rock. This report summarizes the characterization done on samples of the Bullfrog Member of the Crater Flat Tuff (Tcfb) used for Waste Package experimental programs. 11 references, 17 figures, 3 tables

  14. Geohydrology of Bandelier Tuff

    International Nuclear Information System (INIS)

    Abeele, M.V.; Wheeler, M.L.; Burton, B.W.

    1981-10-01

    The Los Alamos National Laboratory has been disposing of radioactive wastes since 1944. Environmental studies and monitoring for radioactive contamination started concurrently. In this report, only two mechanisms and rates by which the radionuclides can enter the environment are studied in detail: subsurface transport of radionuclides by migrating water, and diffusion of tritiated water (HTO) in the vapor phase. The report also includes a section concerning the influence of moisture on shear strength and possible resulting subsidences occurring in the pit overburdens. Because subsurface transport of radionuclides is influenced by the hydraulic conductivity and this in turn is regulated by the moisture content of any given material, a study was also undertaken involving precipitation, the most important climatic element influencing the geohydrology of any given area. Further work is in progress to correlate HTO emanation to atmospheric and pedological properties, especially including thermal characteristics of the tuff

  15. Geohydrology of Bandelier Tuff

    Energy Technology Data Exchange (ETDEWEB)

    Abeele, M.V.; Wheeler, M.L.; Burton, B.W.

    1981-10-01

    The Los Alamos National Laboratory has been disposing of radioactive wastes since 1944. Environmental studies and monitoring for radioactive contamination started concurrently. In this report, only two mechanisms and rates by which the radionuclides can enter the environment are studied in detail: subsurface transport of radionuclides by migrating water, and diffusion of tritiated water (HTO) in the vapor phase. The report also includes a section concerning the influence of moisture on shear strength and possible resulting subsidences occurring in the pit overburdens. Because subsurface transport of radionuclides is influenced by the hydraulic conductivity and this in turn is regulated by the moisture content of any given material, a study was also undertaken involving precipitation, the most important climatic element influencing the geohydrology of any given area. Further work is in progress to correlate HTO emanation to atmospheric and pedological properties, especially including thermal characteristics of the tuff.

  16. NATIONAL GEOSCIENCE DATA REPOSITORY SYSTEM PHASE III: IMPLEMENTATION AND OPERATION OF THE REPOSITORY

    Energy Technology Data Exchange (ETDEWEB)

    Marcus Milling

    2002-10-01

    The NGDRS has facilitated 85% of cores, cuttings, and other data identified available for transfer to the public sector. Over 12 million linear feet of cores and cuttings, in addition to large numbers of paleontological samples and are now available for public use. To date, with industry contributions for program operations and data transfers, the NGDRS project has realized a 6.5 to 1 return on investment to Department of Energy funds. Large-scale transfers of seismic data have been evaluated, but based on the recommendation of the NGDRS steering committee, cores have been given priority because of the vast scale of the seismic data problem relative to the available funding. The rapidly changing industry conditions have required that the primary core and cuttings preservation strategy evolve as well. Additionally, the NGDRS clearinghouse is evaluating the viability of transferring seismic data covering the western shelf of the Florida Gulf Coast. AGI remains actively involved in working to realize the vision of the National Research Council's report of geoscience data preservation. GeoTrek has been ported to Linux and MySQL, ensuring a purely open-source version of the software. This effort is key in ensuring long-term viability of the software so that is can continue basic operation regardless of specific funding levels. Work has commenced on a major revision of GeoTrek, using the open-source MapServer project and its related MapScript language. This effort will address a number of key technology issues that appear to be rising for 2002, including the discontinuation of the use of Java in future Microsoft operating systems. Discussions have been held regarding establishing potential new public data repositories, with hope for final determination in 2002.

  17. Encapsulation plant preliminary design, phase 2. Repository connected facility

    International Nuclear Information System (INIS)

    Kukkola, T.

    2006-12-01

    The disposal facility of the spent nuclear fuel will be located in Olkiluoto. The encapsulation plant is a part of the disposal facility. In this report, an independent encapsulation plant is located above the underground repository. In the encapsulation plant, the spent fuel is received and treated for disposal. In the fuel handling cell, the spent fuel assemblies are unloaded from the spent fuel transport casks and loaded into the disposal canisters. The gas atmosphere of the disposal canister is changed, the bolted inner canister lid is closed, and the electron beam welding method is used to close the lid of the outer copper canister. The disposal canisters are cleaned and transferred into the buffer store after the machining and inspection of the copper lid welds. From the buffer store, the disposal canisters are transferred into the repository spaces by help of the canister lift. All needed stages of operation are to be performed safely without any activity releases or remarkable personnel doses. The bentonite block interim storage is associated with the encapsulation plant. The bentonite blocks are made from bentonite powder. The bentonite blocks are used as buffer material around the disposal canister in the deposition hole. The average production rate of the encapsulation plant is 40 canisters per year. The nominal maximum production capacity is 100 canisters per year in one shift operation. (orig.)

  18. Mechanical excavator performance in Yucca Mountain tuffs

    International Nuclear Information System (INIS)

    Ozdemir, L.; Hansen, F.D.

    1991-01-01

    A research effort of four phases is in progress at the Colorado School of Mines. The overall program will evaluate the cutability of welded tuff and other lithologies likely to be excavated at Yucca Mountain in the site characterization process. Several mechanical systems are considered with emphasis given to the tunnel boring machine. The research comprises laboratory testing, linear drag bit and disc cutter tests and potentially large-scale laboratory demonstrations to support potential use of a tunnel boring machine in welded tuff. Preliminary estimates of mechanical excavator performance in Yucca Mountain tuff are presented here. As phases of the research project are completed, well quantified estimates will be made of performance of mechanical excavators in the Yucca Mountain tuffs. 3 refs., 2 tabs

  19. Natural language solution to a Tuff problem

    International Nuclear Information System (INIS)

    Langkopf, B.S.; Mallory, L.H.

    1984-01-01

    A scientific data base, the Tuff Data Base, is being created at Sandia National Laboratories on the Cyber 170/855, using System 2000. It is being developed for use by scientists and engineers investigating the feasibility of locating a high-level radioactive waste repository in tuff (a type of volcanic rock) at Yucca Mountain on and adjacent to the Nevada Test Site. This project, the Nevada Nuclear Waste Storage Investigations (NNWSI) Project, is managed by the Nevada Operations Office of the US Department of Energy. A user-friendly interface, PRIMER, was developed that uses the Self-Contained Facility (SCF) command SUBMIT and System 2000 Natural Language functions and parametric strings that are schema resident. The interface was designed to: (1) allow users, with or without computer experience or keyboard skill, to sporadically access data in the Tuff Data Base; (2) produce retrieval capabilities for the user quickly; and (3) acquaint the users with the data in the Tuff Data Base. This paper gives a brief description of the Tuff Data Base Schema and the interface, PRIMER, which is written in Fortran V. 3 figures

  20. Sorption of radionuclides on Yucca Mountain tuffs

    International Nuclear Information System (INIS)

    Meijaer, A.; Triay, I.; Knight, S.; Cisneros, M.

    1989-01-01

    A substantial database of sorption coefficients for important radionuclides on Yucca Mountain tuffs has been obtained by Los Alamos National Laboratory over the past ten years. Current sorption studies are focussed on validation questions and augmentation of the existing database. Validation questions concern the effects of the use of crushed instead of solid rock samples in the batch experiments, the use of oversaturated stock solutions, and variations in water/rock ratios. Sorption mechanisms are also being investigated. Database augmentation activities include determination of sorption coefficients for elements with low sorption potential, sorption on psuedocolloids, sorption on fracture lining minerals, and sorption kinetics. Sorption can provide an important barrier to the potential migration of radionuclides from the proposed repository within Yucca Mountain to the accessible environment. In order to quantify this barrier, sorption coefficients appropriate for the Yucca Mountain groundwater system must be obtained for each of the important radionuclides in nuclear waste. Los Alamos National Laboratories has conducted numerous batch (crushed-rock) sorption experiments over the past ten years to develop a sorption coefficient database for the Yucca Mountain site. In the present site characterization phase, the main goals of the sorption test program will be to validate critical sorption coefficients and to augment the existing database where important data are lacking. 11 refs., 1 fig., 3 tabs

  1. Petrology of tuff units from the J-13 drill site, Jackass Flats, Nevada

    International Nuclear Information System (INIS)

    Heiken, G.H.; Bevier, M.L.

    1979-01-01

    The J-13 drill hole, located in Jackass Flats, Nevada Test Site, has penetrated 125 m of alluvium and 932 m of tuff. Most of the tuff deposits consist of welded tuffs; glass phases in the tuffs have been replaced by authigenic minerals, mainly K-feldspar, silica, and zeolites. The zonation of authigenic minerals, with depth, indictes that alteration of glass phases and filling of vugs occurred during welding and compaction of tuff units soon after deposition and by interaction with groundwater. Zonation of authigenic minerals in tuff deposits at Jackass Flats is similar to mineral zonation in tuffs elsewhere at the Nevada Test Site and in tuff deposits of west Texas. All appear to have been developed by leaching of glass phases and deposition of authigenic minerals in open hydrologic systems. 10 figures, 38 tables

  2. Infiltration and Seepage Through Fractured Welded Tuff

    Energy Technology Data Exchange (ETDEWEB)

    T.A. Ghezzehei; P.F. Dobson; J.A. Rodriguez; P.J. Cook

    2006-06-20

    The Nopal I mine in Pena Blanca, Chihuahua, Mexico, contains a uranium ore deposit within fractured tuff. Previous mining activities exposed a level ground surface 8 m above an excavated mining adit. In this paper, we report results of ongoing research to understand and model percolation through the fractured tuff and seepage into a mined adit both of which are important processes for the performance of the proposed nuclear waste repository at Yucca Mountain. Travel of water plumes was modeled using one-dimensional numerical and analytical approaches. Most of the hydrologic properly estimates were calculated from mean fracture apertures and fracture density. Based on the modeling results, we presented constraints for the arrival time and temporal pattern of seepage at the adit.

  3. Effects of mineralogy on sorption of strontium and cesium onto Calico Hills Tuff

    International Nuclear Information System (INIS)

    Meyer, R.E.; Arnold, W.D.; Case, F.I.; O'Kelley, G.D.; Land, J.F.

    1990-04-01

    The sorption properties of tuff formations at the proposed site for the high-level nuclear waste repository at Yucca Mountain, Nevada, have been extensively studied. Sorption and desorption measurements were made of strontium and cesium onto clinoptilolite and Calico Hills Tuff. The object was to see whether there was a correlation between sorption of strontium and cesium onto Calico Hills Tuff and the sorption of strontium and cesium onto clinoptilolite based on the content of clinoptilolite in the Calico Hills Tuff. 13 refs., 10 figs., 6 tabs

  4. NRC iterative performance assessment Phase 2. Development of capabilities for review of a performance assessment for a high-level waste repository

    International Nuclear Information System (INIS)

    Wescott, R.G.; Lee, M.P.; Eisenberg, N.A.; Baca, R.G.

    1995-10-01

    In order to better review a potential license application to construct and operate a geologic repository for spent nuclear fuel and high-level radioactive waste (HLW), the Nuclear Regulatory Commission staff (and its contractor) has expanded and improved its capability to conduct performance assessments. This report documents the demonstration of the second phase of this capability. The demonstration made use of the scenario selection procedure developed by Sandia National Laboratories to provide a set of scenarios, with corresponding probabilities, for use in the consequence analysis of a potential HLW disposal site in unsaturated tuff. Models of release of radionuclides from the waste form and transport in ground water, air and by direct pathways provided preliminary estimates of releases to the accessible environment for a 10,000 year period. The input values of parameters necessary for the consequence models were sampled numerous times using Latin Hypercube Sampling from assumed probability distributions. The results from the consequence models were then used to generate Complementary Cumulative Distribution Functions (CCDFs) for either release to the accessible environment or effective dose equivalents to a target population. CCDFs were calculated for probabilistically significant combinations (scenarios) of four disruptive events; drilling, pluvial climate, seismicity and magmatism. Sensitivity and uncertainty analyses of the calculated releases and effective dose equivalents were also used to determine the importance of the parameters. Because of the preliminary nature of the analysis and the lack of an adequate data base, the results and conclusions presented in this report should be carefully interpreted. They should not be misconstrued to represent the actual performance of the proposed Yucca Mountain repository nor serve as an endorsement of the methods used

  5. National Geoscience Data Repository System, Phase II. Final report, January 30, 1995--January 28, 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    The American Geological Institute (AGI) has completed Phase II of a project to establish a National Geoscience Data Repository System (NGDRS). The project`s primary objectives are to preserve geoscience data in jeopardy of being destroyed and to make that data available to those who have a need to use it in future investigations. These data are available for donation to the public as a result of the downsizing that has occurred in the major petroleum and mining companies in the United States for the past decade. In recent years, these companies have consolidated domestic operations, sold many of their domestic properties and relinquished many of their leases. The scientific data associated with those properties are no longer considered to be useful assets and are consequently in danger of being lost forever. The national repository project will make many of these data available to the geoscience community for the first time. To address this opportunity, AGI sought support from the Department of Energy (DOE) in 1994 to initiate the NGDRS Phase I feasibility study to determine the types and quantity of data that companies would be willing to donate. The petroleum and mining companies surveyed indicated that they were willing to donate approximately five million well logs, one hundred million miles of seismic reflection data, millions of linear feet of core and cuttings, and a variety of other types of scientific data. Based on the positive results of the Phase I study, AGI undertook Phase II of the program in 1995. Funded jointly by DOE and industry, Phase II encompasses the establishment of standards for indexing and cataloging of geoscience data and determination of the costs of transferring data from the private sector to public-sector data repositories. Pilot projects evaluated the feasibility of the project for transfer of different data types and creation of a Web-based metadata supercatalog and browser.

  6. Long-Term Information Management (LTIM) of Safeguards Data at Repositories: Phase II

    International Nuclear Information System (INIS)

    Haddal, Risa N.

    2016-01-01

    One of the challenges of implementing safeguards for geological repositories will be the long-term preservation of safeguards-related data for 100 years or more. While most countries considering the construction and operation of such facilities agree that safeguards information should be preserved, there are gaps with respect to standardized requirements, guidelines, timescales, and approaches. This study analyzes those gaps and explores research to clarify stakeholder needs, identify current policies, approaches, best practices and international standards, and explores existing safeguards information management infrastructure. The study also attempts to clarify what a safeguards data classification system might look like, how long data should be retained, and how information should be exchanged between stakeholders at different phases of a repository's life cycle. The analysis produced a variety of recommendations on what information to preserve, how to preserve it, where to store it, retention options and how to exchange information in the long term. Key findings include the use of the globally recognized international records management standard, ISO15489, for guidance on the development of information management systems, and the development of a Key Information File (KIF). The KIF could be used to identify only the most relevant, high-level safeguards information and the history of decision making about the repository. The study also suggests implementing on-site and off-site records storage in digital and physical form; developing a safeguards data classification system; long-term records retention with periodic reviews every 5 to 10 years during each phase of the repository life cycle; and establishing transition procedures well in advance so that data shepherds and records officers can transfer information with incoming facility managers effectively and efficiently. These and other recommendations are further analyzed in this study.

  7. Potential site selection for radioactive waste repository using GIS (Study area: Negeri Sembilan) - Phase 1

    International Nuclear Information System (INIS)

    Ahmad Hasnulhadi Che Kamaruddin; Faizal Azrin Abdul Razalim; Mohd Abdul Wahab Yusof; Nik Marzukee Nik Ibrahim; Nazran Harun; Muhammad Fathi Sujan; Karuppiah, T.; Surip, N.; Malik, N.N.A.; Che Musa, R.

    2010-01-01

    The main purpose in this paper is to create the Geographic Information System (GIS) based analysis on the potential site area for near-surface radioactive waste repository in the state of Negeri Sembilan. There are several parameters should be considered related to the safety assessment in selecting the potential site. These parameters such as land-use, urban area, soil, rainfall, lithology, lineament, geomorphology, landslide potential, slope, elevation, hydrogeology and protected land need to be considered before choosing the site. In this phase, we only consider ten parameters for determining the potential suitable site. (author)

  8. SAFOD Phase III Core Sampling and Data Management at the Gulf Coast Repository

    Directory of Open Access Journals (Sweden)

    David Lockner

    2011-03-01

    Full Text Available The San Andreas Fault Observatory at Depth (SAFODproject is yielding new insight into the San Andreas Fault (Zoback et al., 2010; Zoback et al., this issue. SAFOD drilling started in 2002 with a pilot hole, and proceeded with three phrases of drilling and coring during the summers of 2004, 2005, and 2007 (Fig. 1. One key component of theproject is curation, sampling, and documentation of SAFOD core usage at the Integrated Ocean Drilling Program’s (IODP Gulf Coast Repository (GCR at Texas A&M University. We present here the milestones accomplished over the past two years of sampling Phase III core at the GCR.

  9. G-Tunnel welded tuff mining experiment data summary

    International Nuclear Information System (INIS)

    Zimmerman, R.M.; Bellman, R.A. Jr.; Mann, K.L.; Zerga, D.P.; Fowler, M.

    1990-03-01

    Designers and analysts of radioactive waste repositories must be ably to predict the mechanical behavior of the host rock. Sandia National Laboratories elected to conduct a mine-by in welded tuff so that predictive-type information could be obtained regarding the response of the rock to a drill and blast excavation process, where smooth blasting techniques were used. Included in the study were evaluations of and recommendations for various measurement systems that might be used in future mine by efforts. This report summarizes all of the data obtained in the welded tuff mining experiment. 6 refs., 29 figs., 12 tabs

  10. Long-Term Information Management (LTIM) of Safeguards Data at Repositories: Phase II

    Energy Technology Data Exchange (ETDEWEB)

    Haddal, Risa N. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-10-01

    One of the challenges of implementing safeguards for geological repositories will be the long-term preservation of safeguards-related data for 100 years or more. While most countries considering the construction and operation of such facilities agree that safeguards information should be preserved, there are gaps with respect to standardized requirements, guidelines, timescales, and approaches. This study analyzes those gaps and explores research to clarify stakeholder needs, identify current policies, approaches, best practices and international standards, and explores existing safeguards information management infrastructure. The study also attempts to clarify what a safeguards data classification system might look like, how long data should be retained, and how information should be exchanged between stakeholders at different phases of a repository’s life cycle. The analysis produced a variety of recommendations on what information to preserve, how to preserve it, where to store it, retention options and how to exchange information in the long term. Key findings include the use of the globally recognized international records management standard, ISO15489, for guidance on the development of information management systems, and the development of a Key Information File (KIF). The KIF could be used to identify only the most relevant, high-level safeguards information and the history of decision making about the repository. The study also suggests implementing on-site and off-site records storage in digital and physical form; developing a safeguards data classification system; long-term records retention with periodic reviews every 5 to 10 years during each phase of the repository life cycle; and establishing transition procedures well in advance so that data shepherds and records officers can transfer information with incoming facility managers effectively and efficiently. These and other recommendations are further analyzed in this study.

  11. Characterizing unsaturated diffusion in porous tuff gravel

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Qinhong; Kneafsey, Timothy J.; Roberts, Jeffery J.; Tomutsa, Liviu; Wang, Joseph, S.Y.

    2003-11-12

    Evaluation of solute diffusion in unsaturated porous gravel is very important for investigations of contaminant transport and remediation, risk assessment, and waste disposal (for example, the potential high-level nuclear waste repository at Yucca Mountain, Nevada). For a porous aggregate medium such as granular tuff, the total water content is comprised of surface water and interior water. The surface water component (water film around grains and pendular water between the grain contacts) could serve as a predominant diffusion pathway. To investigate the extent to which surface water films and contact points affect solute diffusion in unsaturated gravel, we examined the configuration of water using x-ray computed tomography in partially saturated gravel, and made quantitative measurements of diffusion at multiple water contents using two different techniques. In the first, diffusion coefficients of potassium chloride in 2-4 mm granular tuff at multiple water contents were calculated from electrical conductivity measurements using the Nernst-Einstein equation. In the second, we used laser ablation with inductively coupled plasma-mass spectrometry to perform micro-scale mapping, allowing the measurement of diffusion coefficients for a mixture of chemical tracers for tuff cubes and tetrahedrons having two contact geometries (cube-cube and cube-tetrahedron). The x-ray computed tomography images show limited contact between grains, and this could hinder the pathways for diffusive transport. Experimental results show the critical role of surface water in controlling transport pathways and hence the magnitude of diffusion. Even with a bulk volumetric water content of 1.5%, the measured solute diffusion coefficient is as low as 1.5 x 10{sup -14} m{sup 2}/s for tuff gravel. Currently used diffusion models relating diffusion coefficients to total volumetric water content inadequately describe unsaturated diffusion behavior in porous gravel at very low water contents.

  12. Role of Accessory Phase Crystallization Within the High-Silica Magma Batches of the Rainier Mesa Tuff, Southwest Nevada Volcanic Field

    Science.gov (United States)

    Tefend, K. S.; Vogel, T. A.; Patino, L. C.

    2004-05-01

    Compositionally zoned ignimbrites from the Timber Mountain/Oasis Valley magmatic system, Southwest Nevada Volcanic Field (SWNVF), represent open system processes as opposed to in situ differentiation within a single magma chamber. The large chemical variation of the pumice fragments in the ash-flow sheets are due to emplacement of different magma batches into the magma chamber prior to eruption1,2. The 11.6 Ma Rainier Mesa tuff is a large (1200 km3) ignimbrite containing low-silica pumice fragments, and two distinct high-silica rhyolitic pumice fragments, distinguished by the Th/Nb ratios1. Based on trace element modeling, Mills et al. (1997) concluded that these were three separate magma batches. Recent δ 18O data from minerals separated from pumice fragments are consistent with this interpretation for the independent origin of the high- and low-silica magmas, and that these represent distinct magma types that erupted coevally1,3. However, chemical data from melt inclusions and glass matrix from the two high-silica magma types do not support the model that these are unrelated. Melt inclusion and glass matrix compositions were obtained from the high-Th/Nb, high-silica and low-Th/Nb, high-silica pumice fragments. The two groups of pumice fragments have identical glass matrix major and trace element compositions, and both high-silica groups have identical melt inclusion compositions. In both high-silica groups, Th and Th/Nb increase with increasing La within the melt inclusions. The two high-silica magma types have identical major phase minerals of similar compositions, indicating that the trace element signature of the whole pumice is controlled by accessory phase fractionation. Analyses of monazite, apatite, and zircon from both high-silica pumice groups show similar compositions, with La and Th concentrated in the monazite. Our interpretation is that the high-Th/Nb, high-silica magma represents accessory phase (monazite) accumulation, resulting in a compositional

  13. G-Tunnel Welded Tuff Mining Experiment instrumentation evaluations

    International Nuclear Information System (INIS)

    Zimmerman, R.M.; Bellman, R.A. Jr.; Mann, K.L.; Thompson, T.W.

    1992-04-01

    Designers and analysts of radioactive waste repositories must be able to predict the mechanical behavior of the host rock. Sandia National Laboratory has conducted a mine-by experiment in welded tuff so that information could be obtained regarding the response of the rock to a drill and blast excavation process, where smooth-blasting techniques were used. This report describes the results of the evaluations of nine different instrument or measurement systems used in conjunction with these mining activities

  14. Age, composition, and areal distribution of the Pliocene Lawlor Tuff, and three younger Pliocene tuffs, California and Nevada

    Science.gov (United States)

    Sarna-Wojcicki, Andrei M.; Deino, Alan L.; Fleck, Robert J.; McLaughlin, Robert J.; Wagner, David; Wan, Elmira; Wahl, David B.; Hillhouse, John W.; Perkins, Michael

    2011-01-01

    The Lawlor Tuff is a widespread dacitic tephra layer produced by Plinian eruptions and ash flows derived from the Sonoma Volcanics, a volcanic area north of San Francisco Bay in the central Coast Ranges of California, USA. The younger, chemically similar Huichica tuff, the tuff of Napa, and the tuff of Monticello Road sequentially overlie the Lawlor Tuff, and were erupted from the same volcanic field. We obtain new laser-fusion and incremental-heating 40Ar/39Ar isochron and plateau ages of 4.834 ± 0.011, 4.76 ± 0.03, ≤4.70 ± 0.03, and 4.50 ± 0.02 Ma (1 sigma), respectively, for these layers. The ages are concordant with their stratigraphic positions and are significantly older than those determined previously by the K-Ar method on the same tuffs in previous studies.Based on offsets of the ash-flow phase of the Lawlor Tuff by strands of the eastern San Andreas fault system within the northeastern San Francisco Bay area, total offset east of the Rodgers Creek–Healdsburg fault is estimated to be in the range of 36 to 56 km, with corresponding displacement rates between 8.4 and 11.6 mm/yr over the past ∼4.83 Ma.We identify these tuffs by their chemical, petrographic, and magnetic characteristics over a large area in California and western Nevada, and at a number of new localities. They are thus unique chronostratigraphic markers that allow correlation of marine and terrestrial sedimentary and volcanic strata of early Pliocene age for their region of fallout. The tuff of Monticello Road is identified only near its eruptive source.

  15. Further description of the petrology of the Topopah Spring member of the paintbrush tuff in drill holes UE25A-1 and USW-G1 and of the lithic-rich tuff in USW-G1, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Carroll, P.I.; Caporuscio, F.A.; Bish, D.L.

    1981-11-01

    The Topopah Spring Member of the Paintbrush Tuff and the Lithic-rich tuff and two Tertiary volcanic units that occur in cores from drill holes UE25a-1 and USW-G1 at Yucca Mountain, Nevada. Recently they have been suggested as possibly suitable for the permanent storage of high-level radioactive waste. Earlier petrologic characterization of these units is augmented here. The Topopah Spring Member (approximately 350 m thick) has two compound cooling units. The upper, thinner unit is densely welded to vitrophyric. The lower unit ranges from nonwelded to vitrophyric, and its nonwelded base is extensively zeolitized to clinoptilolite and mordenite. Heulandite occurs as fracture fill in the overlying vitrophyric part, but zeolites are absent above that vitrophyre. Here primary devitrification plus vapor-phase crystallization dominate the mineralogy. Vapor-phase effects are especially prominent between the two vitrophyres in both cores and include numerous large lithophysal cavities throughout most of this moderately to densely welded tuff. The Lithic-rich tuff extends from 1203 to 1506 m in the USW-G1 drill core. It is nonwelded to partly welded but is well indurated due to pervasive intergrowths of authigenic minerals. These phases are analcime, albite, alkali feldspar, sericite, chlorite and quartz. The transition from analcime to secondary albite corresponds to Iijima's zeolite Zone IV boundary, and this boundary appears in USW-G1 at 1326 m. However, analcime remains as a prominent phase through most of the Lithic-rich tuff. Further work is necessary to assess the suitability of either of these horizons for a waste repository. In the Topopah Spring Member, both mechanical and hydrologic properties of thick lithophysal zone must be studied, as well as the complete sequence of fracture fill. For both units, zeolite and clay mineral stabilities need to be investigated

  16. METHODS FOR PORE WATER EXTRACTION FROM UNSATURATED ZONE TUFF, YUCCA MOUNTAIN, NEVADA

    International Nuclear Information System (INIS)

    K.M. SCOFIELD

    2006-01-01

    Assessing the performance of the proposed high-level radioactive waste repository at Yucca Mountain, Nevada, requires an understanding of the chemistry of the water that moves through the host rock. The uniaxial compression method used to extract pore water from samples of tuffaceous borehole core was successful only for nonwelded tuff. An ultracentrifugation method was adopted to extract pore water from samples of the densely welded tuff of the proposed repository horizon. Tests were performed using both methods to determine the efficiency of pore water extraction and the potential effects on pore water chemistry. Test results indicate that uniaxial compression is most efficient for extracting pore water from nonwelded tuff, while ultracentrifugation is more successful in extracting pore water from densely welded tuff. Pore water splits taken from a single nonwelded tuff core during uniaxial compression tests have shown changes in pore water chemistry with increasing pressure for calcium, chloride, sulfate, and nitrate, while the chemistry of pore water splits from welded and nonwelded tuffs using ultracentrifugation indicates that there is no significant fractionation of solutes

  17. Uncertainty and sensitivity analysis for two-phase flow in the vicinity of the repository in the 1996 performance assessment for the Waste Isolation Pilot Plant: Disturbed conditions

    Energy Technology Data Exchange (ETDEWEB)

    HELTON,JON CRAIG; BEAN,J.E.; ECONOMY,K.; GARNER,J.W.; MACKINNON,ROBERT J.; MILLER,JOEL D.; SCHREIBER,J.D.; VAUGHN,PALMER

    2000-05-22

    Uncertainty and sensitivity analysis results obtained in the 1996 performance assessment (PA) for the Waste Isolation Pilot Plant (WIPP) are presented for two-phase flow in the vicinity of the repository under disturbed conditions resulting from drilling intrusions. Techniques based on Latin hypercube sampling, examination of scatterplots, stepwise regression analysis, partial correlation analysis and rank transformations are used to investigate brine inflow, gas generation repository pressure, brine saturation and brine and gas outflow. Of the variables under study, repository pressure and brine flow from the repository to the Culebra Dolomite are potentially the most important in PA for the WIPP. Subsequent to a drilling intrusion repository pressure was dominated by borehole permeability and generally below the level (i.e., 8 MPa) that could potentially produce spallings and direct brine releases. Brine flow from the repository to the Culebra Dolomite tended to be small or nonexistent with its occurrence and size also dominated by borehole permeability.

  18. Science is the first step to siting nuclear waste repositories

    Science.gov (United States)

    Neuzil, Christopher E.

    2014-01-01

    As Shaw [2014] notes, U.S. research on shale as a repository host was halted before expending anything close to the effort devoted to studying crystalline rock, salt, and - most notably - tuff at Yucca Mountain. The new political reality regarding Yucca Mountain may allow reconsideration of the decision to abandon research on shale as a repository host.

  19. Prototype Repository. Tracer dilution tests during operation phase, test campaign 3

    Energy Technology Data Exchange (ETDEWEB)

    Harrstroem, Johan; Andersson, Peter (Geosigma AB (Sweden))

    2010-05-15

    The Prototype Repository project is focused on testing and demonstrating the function of the SKB deep repository system. The third tracer dilution campaign during the Prototype Repository operation period was performed in January 2010. The purpose was to estimate the groundwater flows and hydraulic gradients in the boreholes vicinity and will function as a reference for comparison with results from modeling and prior assumptions. The test campaign consisted of tracer dilution tests in 13 different borehole sections. Each test consisted of approximately 15-55 min tracer injection time and about 1-3 days dilution test time depending on the transmissivity of the test section. The data interpretation also included estimates of the local hydraulic gradients in the vicinity of the borehole sections

  20. G-tunnel welded tuff mining experiment preparations

    International Nuclear Information System (INIS)

    Zimmerman, R.M.; Bellman, R.A. Jr.; Mann, K.L.; Zerga, D.P.

    1991-01-01

    Designers and analysts of radioactive waste repositories must be able to predict the mechanical behavior of the host rock. Sandia National Laboratories elected to conduct a mine-by in welded tuff so that predictive-type information could be obtained regarding the response of the rock to a drill and blast excavation process, where smooth blasting techniques were used. Included in the study were evaluations of and recommendations for various measurement systems that might be used in future mine-by efforts. This report summarizes the preparations leading to the recording of data. 17 refs., 27 figs., 5 tabs

  1. Effect of radiation on the mechanical properties of Topopah Spring Tuff

    International Nuclear Information System (INIS)

    Blair, S.C.; Kelly, J.M.; Pine, O.; Pletcher, R.; Berge, P.A.

    1996-01-01

    This report presents results of a suite of uniaxial compressive tests conducted to provide laboratory data to determine how radiation affects the compressive strength of Topopah Spring Tuff, which is the rock type for the proposed geologic repository at Yucca Mountain, in Nevada. The repository would be designed for storing spent fuel and other high-level radioactive wastes. We need to better understand what effect radiation has on the compressive strength of this type of rock because emplacement of radioactive waste may impose a radiation field on the rock that is exposed in the emplacement drifts and other excavations associated with the proposed repository. Thus, we must determine whether exposure to radiation will alter the mechanical strength or other geomechanical properties of the rock in the very near-field region of the repository. Until now, data describing the effect of radiation on tuff from the potential repository horizon have not been available. The approach taken was to precisely measure rock behavior in uniaxial compression on irradiated and non-irradiated samples of Topopah Spring Tuff. Identical procedures were used for preparing and testing the samples tested for radiation effects and those that were not irradiated, except for the exposure to gamma radiation. Results for the irradiated and non-irradiated samples were then compared

  2. Measuring geomechanical properties of Topopah Spring Tuff at the 1-meter scale

    International Nuclear Information System (INIS)

    Blair, S.C.; Berge, P.A.

    1994-11-01

    The Yucca Mountain Site Characterization Project is studying physical and chemical properties of Topopah Spring tuff and coupled thermal, mechanical, hydrological, and geochemical processes expected in the near-field environment of the potential waste repository at Yucca Mountain, Nevada. Investigating the suitability of Topopah Spring tuff as a host rock for radioactive waste disposal includes measuring mechanical properties. Since heterogeneities vary with scale, from vugs and cracks at the hand-sample scale to fractures and vertical variations in degree of welding at the outcrop scale, mechanical properties of the tuff depend on scale. The Lawrence Livermore National Laboratory has planned a Large Block Test (LBT) to investigate rock mass properties and coupled processes at elevated temperatures in Topopah Spring tuff at the scale of a few meters. This paper describes planned laboratory experiments in support of the LBT, to measure elastic properties and mechanical behavior of Topopah Spring tuff at the scale of a few cm to 1 m. The laboratory experiments will include measurement of stress-strain behavior, acoustic emissions during heating, and elastic wave velocities in small blocks of tuff

  3. Mineralogy, petrology and whole-rock chemistry data compilation for selected samples of Yucca Mountain tuffs

    International Nuclear Information System (INIS)

    Connolly, J.R.

    1991-12-01

    Petrologic, bulk chemical, and mineralogic data are presented for 49 samples of tuffaceous rocks from core holes USW G-1 and UE-25a number-sign 1 at Yucca Mountain, Nevada. Included, in descending stratigraphic order, are 11 samples from the Topopah Spring Member of the Paintbrush Tuff, 12 samples from the Tuffaceous Beds of Calico Hills, 3 samples from the Prow Pass Member of the Crater Flat Tuff, 20 samples from the Bullfrog Member of the Crater Flat Tuff and 3 samples from the Tram Member of the Crater Flat Tuff. The suite of samples contains a wide variety of petrologic types, including zeolitized, glassy, and devitrified tuffs. Data vary considerably between groups of samples, and include thin section descriptions (some with modal analyses for which uncertainties are estimated), electron microprobe analyses of mineral phases and matrix, mineral identifications by X-ray diffraction, and major element analyses with uncertainty estimates

  4. Performance testing of waste forms in a tuff environment

    International Nuclear Information System (INIS)

    Oversby, V.M.

    1983-11-01

    This paper describes experimental work conducted to establish the chemical composition of water which will have reacted with Topopah Spring Member tuff prior to contact with waste packages. The experimental program to determine the behavior of spent fuel and borosilicate glass in the presence of this water is then described. Preliminary results of experiments using spent fuel segments with defects in the Zircaloy cladding are presented. Some results from parametric testing of a borosilicate glass with tuff and 304L stainless steel are also discussed. Experiments conducted using Topopah Spring tuff and J-13 well water have been conducted to provide an estimate of the post-emplacement environment for waste packages in a repository at Yucca Mountain. The results show that emplacement of waste packages should cause only small changes in the water chemistry and rock mineralogy. The changes in environment should not have any detrimental effects on the performance of metal barriers or waste forms. The NNWSI waste form testing program has provided preliminary results related to the release rate of radionuclides from the waste package. Those results indicate that release rates from both spent fuel and borosilicate glass should be below 1 part in 10 5 per year. Future testing will be directed toward making release rate testing more closely relevant to site specific conditions. 17 references, 7 figures

  5. Transport properties of Topopah Spring tuff

    International Nuclear Information System (INIS)

    Lin, W.; Daily, W.

    1984-10-01

    Electrical resistivity, ultrasonic P-waves velocity, and water permeability were measured simultaneously on both intact and fractured Topopah Spring tuff samples at a confining pressure of 5.0 MPa, pore pressures to 2.5 MPa, and temperatures to 140 0 C. The tested samples were subjected to three dehydration and rehydration cycles. The dehydrations were accomplished at a temperature of 140 0 C, and the rehydrations were accomplished at various combinations of temperature and pore pressures so that the wetting fluid was either liquid water, steam or both. The electrical resistivity measurements indicate that for the intact sample, the drying and resaturation took place fairly uniformly throughout the sample. On the other hand, for the fractured sample, the drying and resaturation was spatially quite nonuniform. When samples had been subjected to 5 MPa of confining pressure and 140 0 C for several weeks, a gradual monotonic drift in resistivity was measured (decreasing resistivity when dry; increasing resistivity when wet). This may be the result of either minerological changes or grain boundary movement. In any case, the phenomenon may have important consequences on long term repository performance, and should be studied further. The permeability of the intact sample was independent of temperature, dehydration and rehydration cycles, and time. The permeability of the fractured sample, initially dominated by the fracture, decreased by about one order of magnitude after each dehydration and rehydration cycle. 11 references, 12 figures, 3 tables

  6. Representation of two-phase flow in the vicinity of the repository in the 1996 performance assessment for the Waste Isolation Pilot Plant

    Energy Technology Data Exchange (ETDEWEB)

    VAUGHN,PALMER; BEAN,J.E.; HELTON,JON CRAIG; LORD,MICHAEL E.; MACKINNON,ROBERT J.; SCHREIBER,JAMES D.

    2000-05-18

    The following topics related to the representation of two-phase (gas and brine) flow in the vicinity of the repository in the 1996 performance assessment (PA) for the Waste Isolation Pilot Plant (WIPP) are discussed: (1) system of nonlinear partial differential equations used to model two-phase flow, (2) incorporation of repository shafts into model (3) creep closure of repository. (4) interbed fracturing, (5) gas generation (6) capillary action in waste, (7) borebole model (8) numerical solution and (9) gas and brine flow across specified boundaries. Two-phase flow calculations are a central part of the 1996 WIPP PA and supply results that are subsequently used in the calculation of releases to the surface at the time of a drilling intrusion (i.e., spallings, direct brine releases) and long-term releases due to radionuclide transport by flowing groundwater.

  7. Representation of two-phase flow in the vicinity of the repository in the 1996 performance assessment for the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    VAUGHN, PALMER; BEAN, J.E.; HELTON, JON CRAIG; LORD, MICHAEL E.; MACKINNON, ROBERT J.; SCHREIBER, JAMES D.

    2000-01-01

    The following topics related to the representation of two-phase (gas and brine) flow in the vicinity of the repository in the 1996 performance assessment (PA) for the Waste Isolation Pilot Plant (WIPP) are discussed: (1) system of nonlinear partial differential equations used to model two-phase flow, (2) incorporation of repository shafts into model (3) creep closure of repository. (4) interbed fracturing, (5) gas generation (6) capillary action in waste, (7) borebole model (8) numerical solution and (9) gas and brine flow across specified boundaries. Two-phase flow calculations are a central part of the 1996 WIPP PA and supply results that are subsequently used in the calculation of releases to the surface at the time of a drilling intrusion (i.e., spallings, direct brine releases) and long-term releases due to radionuclide transport by flowing groundwater

  8. LITHOSTRATIGRAPHY AND SHEAR-WAVE VELOCITY IN THE CRYSTALLIZED TOPOPAH SPRING TUFF, YUCCA MOUNTAIN, NEVADA

    International Nuclear Information System (INIS)

    D. BUESCH; K.H. STOKOE; M. SCHUHEN

    2006-01-01

    Evaluation of the seismic response of the proposed spent nuclear fuel and high-level radioactive waste repository at Yucca Mountain, Nevada, is in part based on the seismic properties of the host rock, the 12.8-million-year-old Topopah Spring Tuff. Because of the processes that formed the tuff, the densely welded and crystallized part has three lithophysal and three nonlithophysal zones, and each zone has characteristic variations in lithostratigraphic features and structures of the rocks. Lithostratigraphic features include lithophysal cavities, rims on lithophysae and some fractures, spots (which are similar to rims but without an associated cavity or aperture), amounts of porosity resulting from welding, crystallization, and vapor-phase corrosion and mineralization, and fractures. Seismic properties, including shear-wave velocity (V s ), have been measured on 38 pieces of core, and there is a good ''first order'' correlation with the lithostratigraphic zones; for example, samples from nonlithophysal zones have larger V s values compared to samples from lithophysal zones. Some samples have V s values that are beyond the typical range for the lithostratigraphic zone; however, these samples typically have one or more fractures, ''large'' lithophysal cavities, or ''missing pieces'' relative to the sample size. Shear-wave velocity data measured in the tunnels have similar relations to lithophysal and nonlithophysal rocks; however, tunnel-based values are typically smaller than those measured in core resulting from increased lithophysae and fracturing effects. Variations in seismic properties such as V s data from small-scale samples (typical and ''flawed'' core) to larger scale traverses in the tunnels provide a basis for merging our understanding of the distributions of lithostratigraphic features (and zones) with a method to scale seismic properties

  9. LITHOSTRATIGRAPHY AND SHEAR-WAVE VELOCITY IN THE CRYSTALLIZED TOPOPAH SPRING TUFF, YUCCA MOUNTAIN, NEVADA

    Energy Technology Data Exchange (ETDEWEB)

    D. BUESCH; K.H. STOKOE; M. SCHUHEN

    2006-03-20

    Evaluation of the seismic response of the proposed spent nuclear fuel and high-level radioactive waste repository at Yucca Mountain, Nevada, is in part based on the seismic properties of the host rock, the 12.8-million-year-old Topopah Spring Tuff. Because of the processes that formed the tuff, the densely welded and crystallized part has three lithophysal and three nonlithophysal zones, and each zone has characteristic variations in lithostratigraphic features and structures of the rocks. Lithostratigraphic features include lithophysal cavities, rims on lithophysae and some fractures, spots (which are similar to rims but without an associated cavity or aperture), amounts of porosity resulting from welding, crystallization, and vapor-phase corrosion and mineralization, and fractures. Seismic properties, including shear-wave velocity (V{sub s}), have been measured on 38 pieces of core, and there is a good ''first order'' correlation with the lithostratigraphic zones; for example, samples from nonlithophysal zones have larger V{sub s} values compared to samples from lithophysal zones. Some samples have V{sub s} values that are beyond the typical range for the lithostratigraphic zone; however, these samples typically have one or more fractures, ''large'' lithophysal cavities, or ''missing pieces'' relative to the sample size. Shear-wave velocity data measured in the tunnels have similar relations to lithophysal and nonlithophysal rocks; however, tunnel-based values are typically smaller than those measured in core resulting from increased lithophysae and fracturing effects. Variations in seismic properties such as V{sub s} data from small-scale samples (typical and ''flawed'' core) to larger scale traverses in the tunnels provide a basis for merging our understanding of the distributions of lithostratigraphic features (and zones) with a method to scale seismic properties.

  10. MAJOR REPOSITORY DESIGN ISSUES

    International Nuclear Information System (INIS)

    JACK N. BAILEY, DWAYNE CHESTNUT, JAMES COMPTON AND RICHARD D. SNELL

    1997-01-01

    The Yucca Mountain Project is focused on producing a four-part viability assessment in late FY98. Its four components (design, performance assessment, cost estimate, and licensing development plan) must be consistent. As a tool to compare design and performance assessment options, a series of repository pictures were developed for the sequential time phases of a repository. The boundaries of the time phases correspond to evolution in the engineered barrier system (EBS)

  11. Phase 1 study of metallic cask systems for spent fuel management from reactor to repository. Volume I. Phase 1 study summary

    Energy Technology Data Exchange (ETDEWEB)

    None

    1986-02-01

    It was proposed to perform a systems evaluation of metallic cask systems in order to define and examine the use of various metallic cask concepts or combination of concepts for the overall inventory management of spent fuel starting with its discharge from reactors to its emplacement in geologic repositories. This systems evaluation occurs in three phases. This three phase systems evaluation leads to a definition and recommendation of a sound and practical metallic cask system to accomplish efficient and effective management of spent fuel in the back end of the nuclear fuel cycle. Phase 1 Study objectives: establish system-wide functional criteria and assumptions; perform the systems engineering needed to define the metallic cask concepts and their feasibility; perform a screening evaluation of the technical and economic merits of the concepts; and recommend those to be included for a more detailed systems evaluation in Phase 2. Phase 2 Study objectives: refine the system-wide functional criteria and assumptions; perform the design engineering needed to enhance the validity and workability of those concepts recommended in Phase 1; and perform a more detailed systems evaluation. Phase 3 Study objectives: conclude the systems evaluation and develop an implementation plan. Volume I presents an overview of the detailed systems evaluation presented in Volume II.

  12. Geologic character of tuffs in the unsaturated zone at Yucca Mountain, southern Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Scott, R.B.; Spengler, R.W.; Diehl, S.; Lappin, A.R.; Chornack, M.P.

    1982-12-31

    At Yucca Mountain, a potential site for a high-level nuclear waste repository on the Nevada Test Site in southern Nevada, evaluation of the geologic setting and rock physical properties, along with previous regional hydrologic studies, has provided background that can be used for construction of a preliminary conceptual hydrologic model of the unsaturated zone. The 500-m-thick unsaturated portion of Yucca Mountain consists of alternating layers of two contrasting types of tuff. One type consists of highly fractured, densely welded, relatively nonporous but highly transmissive ash-flow tuffs. The other type consists of relatively unfractured, nonwelded, highly porous but relatively nontransmissive, argillic and zeolitic bedded tuffs and ash-flow tuffs. The contrast between these two sets of distinctive physical properties results in a stratified sequence best described as "physical-property stratigraphy" as opposed to traditional petrologic stratigraphy of volcanic rocks. The vast majority of recharge through the unsaturated zone is assumed to be vertical; the dominant migration may occur in fractures of densely welded tuffs and in the matrix of nonwelded tuff, but the mode of fluid flow in these unsaturated systems is undetermined. Limited lateral flow of recharge may occur at horizons where local perched water tables may exist above relatively nontransmissive zeolitized nonwelded tuffs. The pervasive north-northwest-striking fractures may control the direction of lateral flow of recharge, if any, in the unsaturated zone, and certainly that direction coincides closely with the observed southeasterly flow direction in the saturated zone under Yucca Mountain. Empirical evaluation of this conceptual hydrologic model has begun. 41 refs., 18 figs., 2 tabs.

  13. Geologic character of tuffs in the unsaturated zone at Yucca Mountain, southern Nevada

    International Nuclear Information System (INIS)

    Scott, R.B.; Spengler, R.W.; Diehl, S.; Lappin, A.R.; Chornack, M.P.

    1982-01-01

    At Yucca Mountain, a potential site for a high-level nuclear waste repository on the Nevada Test Site in southern Nevada, evaluation of the geologic setting and rock physical properties, along with previous regional hydrologic studies, has provided background that can be used for construction of a preliminary conceptual hydrologic model of the unsaturated zone. The 500-m-thick unsaturated portion of Yucca Mountain consists of alternating layers of two contrasting types of tuff. One type consists of highly fractured, densely welded, relatively nonporous but highly transmissive ash-flow tuffs. The other type consists of relatively unfractured, nonwelded, highly porous but relatively nontransmissive, argillic and zeolitic bedded tuffs and ash-flow tuffs. The contrast between these two sets of distinctive physical properties results in a stratified sequence best described as ''physical-property stratigraphy'' as opposed to traditional petrologic stratigraphy of volcanic rocks. The vast majority of recharge through the unsaturated zone is assumed to be vertical; the dominant migration may occur in fractures of densely welded tuffs and in the matrix of nonwelded tuff, but the mode of fluid flow in these unsaturated systems is undetermined. Limited lateral flow of recharge may occur at horizons where local perched water tables may exist above relatively nontransmissive zeolitized nonwelded tuffs. The pervasive north-northwest-striking fractures may control the direction of lateral flow of recharge, if any, in the unsaturated zone, and certainly that direction coincides closely with the observed southeasterly flow direction in the saturated zone under Yucca Mountain. Empirical evaluation of this conceptual hydrologic model has begun. 41 refs., 18 figs., 2 tabs

  14. Feldspar dissolution rates in the Topopah Spring Tuff, Yucca Mountain, Nevada

    Science.gov (United States)

    Bryan, C.R.; Helean, K.B.; Marshall, B.D.; Brady, P.V.

    2009-01-01

    Two different field-based methods are used here to calculate feldspar dissolution rates in the Topopah Spring Tuff, the host rock for the proposed nuclear waste repository at Yucca Mountain, Nevada. The center of the tuff is a high silica rhyolite, consisting largely of alkali feldspar (???60 wt%) and quartz polymorphs (???35 wt%) that formed by devitrification of rhyolitic glass as the tuff cooled. First, the abundance of secondary aluminosilicates is used to estimate the cumulative amount of feldspar dissolution over the history of the tuff, and an ambient dissolution rate is calculated by using the estimated thermal history. Second, the feldspar dissolution rate is calculated by using measured Sr isotope compositions for the pore water and rock. Pore waters display systematic changes in Sr isotopic composition with depth that are caused by feldspar dissolution. The range in dissolution rates determined from secondary mineral abundances varies from 10-16 to 10-17 mol s-1 kg tuff-1 with the largest uncertainty being the effect of the early thermal history of the tuff. Dissolution rates based on pore water Sr isotopic data were calculated by treating percolation flux parametrically, and vary from 10-15 to 10-16 mol s-1 kg tuff-1 for percolation fluxes of 15 mm a-1 and 1 mm a-1, respectively. Reconciling the rates from the two methods requires that percolation fluxes at the sampled locations be a few mm a-1 or less. The calculated feldspar dissolution rates are low relative to other measured field-based feldspar dissolution rates, possibly due to the age (12.8 Ma) of the unsaturated system at Yucca Mountain; because oxidizing and organic-poor conditions limit biological activity; and/or because elevated silica concentrations in the pore waters (???50 mg L-1) may inhibit feldspar dissolution. ?? 2009 Elsevier Ltd. All rights reserved.

  15. Two-phase flow in a saliniferous final repository using the example of ERAM. Final report; Zweiphasenfluss in einem salinaren Endlager am Beispiel des ERAM. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Kock, Ingo; Frieling, Gerd; Navarro, Martin

    2016-10-15

    In the frame of the research project ZIESEL the GRS enhanced the state of science and technology for the realization and evaluation of long-term safety cases for the final deposition of radioactive wastes. The superior aim was the improved understanding of two-phase flow processes in a complex final repository system. The consideration of two-phase processes in modeling of final repository systems induces processes and effects that significantly affect the transport behavior of fluid and radionuclides. Two-phase processes include not only capillary pressures and relative permeabilities but also a basic competition of phases with respect to pore volume for storage and transport and density-driven vertical separation of phases. Basically seals have been shown to be essential for the system behavior because of their influence of the gas pressure dependent control function. The system behavior is also influences by the model geometry.

  16. G-Tunnel Welded Tuff Mining Experiment instrumentation evaluations; Yucca Mountain Site Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Zimmerman, R.M. [Sandia National Labs., Albuquerque, NM (United States); Bellman, R.A. Jr.; Mann, K.L.; Thompson, T.W. [Science Applications International Corp., Las Vegas, NV (United States)

    1992-04-01

    Designers and analysts of radioactive waste repositories must be able to predict the mechanical behavior of the host rock. Sandia National Laboratory has conducted a mine-by experiment in welded tuff so that information could be obtained regarding the response of the rock to a drill and blast excavation process, where smooth-blasting techniques were used. This report describes the results of the evaluations of nine different instrument or measurement systems used in conjunction with these mining activities.

  17. Interactions between mobilized radionuclides and secondary phases in final repository-relevant formation aquifers. Final report; Wechselwirkung mobilisierter Radionuklide mit sekundaeren Phasen in endlagerrelevanten Formationswaessern. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Curtius, H.; Kaiser, G.; Paparigas, Z.; Hansen, B.; Neumann, A.; Klinkenberg, M.; Mueller, E.; Bruecher, H.; Bosbach, D.

    2010-10-15

    The report on interactions between mobilized radionuclides and secondary phases in final repository-relevant formation aquifers covers the following issues: scope of study, leaching experiments, secondary phases, incorporation and sorption studies, summary and prospects. The results show that the investigated spent fuels dissolve instantaneously in contact with the repository-relevant aquifers in presence of iron ions. For the elements Cs and Sr no re-immobilization was observed. These elements have to be considered as mobile species in the radionuclide source term. The secondary phases due to corrosion processes are radionuclide sinks, i.e. actinides are re-immobilized, the retention mechanisms were clarified. The studies with irradiated nuclear fuel show that the uranium/silicon containing phases effect the molar solubility of actinides.

  18. Bond strength of cementitious borehole plugs in welded tuff

    International Nuclear Information System (INIS)

    Akgun, H.; Daemen, J.J.K.

    1991-02-01

    Axial loads on plugs or seals in an underground repository due to gas, water pressures and temperature changes induced subsequent to waste and plug emplacement lead to shear stresses at the plug/rock contact. Therefore, the bond between the plug and rock is a critical element for the design and effectiveness of plugs in boreholes, shafts or tunnels. This study includes a systematic investigation of the bond strength of cementitious borehole plugs in welded tuff. Analytical and numerical analysis of borehole plug-rock stress transfer mechanics is performed. The interface strength and deformation are studied as a function of Young's modulus ratio of plug and rock, plug length and rock cylinder outside-to-inside radius ratio. The tensile stresses in and near an axially loaded plug are analyzed. The frictional interface strength of an axially loaded borehole plug, the effect of axial stress and lateral external stress, and thermal effects are also analyzed. Implications for plug design are discussed. The main conclusion is a strong recommendation to design friction plugs in shafts, drifts, tunnels or boreholes with a minimum length to diameter ratio of four. Such a geometrical design will reduce tensile stresses in the plug and in the host rock to a level which should minimize the risk of long-term deterioration caused by excessive tensile stresses. Push-out tests have been used to determine the bond strength by applying an axial load to cement plugs emplaced in boreholes in welded tuff cylinders. A total of 130 push-out tests have been performed as a function of borehole size, plug length, temperature, and degree of saturation of the host tuff. The use of four different borehole radii enables evaluation of size effects. 119 refs., 42 figs., 20 tabs

  19. A natural analogue for high-level waste in tuff: Chemical analysis and modeling of the Valles site

    International Nuclear Information System (INIS)

    Stockman, H.W.; Krumhansl, J.L.; Ho, C.K.; Kovach, L.; McConnell, V.S.

    1995-01-01

    The contact between an obsidian flow and a steep-walled tuff canyon was examined as an analogue for a high-level waste repository. The analogue site is located in the Valles Caldera in New Mexico, where a massive obsidian flow filled a paleocanyon in the Battleship Rock Tuff. The obsidian flow provided a heat source, analogous to waste panels or an igneous intrusion in a repository, and caused evaporation and migration of water. The tuff and obsidian samples were analyzed for major and trace elements and mineralogy by INAA, XRF, x-ray diffraction, and scanning electron microscopy and electron microprobe. Samples were also analyzed for D/H and 39 Ar/ 40 Ar isotopic composition. Overall, the effects of the heating event seem to have been slight and limited to the tuff nearest the contact. There is some evidence of devitrification and migration of volatiles in the tuff within 10 m of the contact, but variations in major and trace element chemistry are small and difficult to distinguish from the natural (pre-heating) variability of the rocks

  20. Pena Blanca uranium deposits and ash-flow tuffs relationship

    International Nuclear Information System (INIS)

    Magonthier, M.

    1987-01-01

    The Pena Blanca uranium deposits (Chihuahua, Mexico) are associated with a Tertiary sequence of ash-flow tuffs. Stratigraphic control is dominant and uranium mineralization occurs in stratiform and fracture-controlled deposits within 44 My-old units: Nopal Rhyolite and Escuadra Rhyolite. These units consist of highly vapor-phase crystallized ash-flow tuffs. They contain sanidine, quartz and granophyric phenocrysts, and minor ferromagnesian silicates. Nopal and Escuadra units are high-silica alkali-rich rhyolites that have a primary potassic character. The trace-element chemistry shows high concentrations in U-Th-Rb-Cs and low contents in Ba-Sr-Eu. These chemical properties imply a genetic relationship between deposits and host-units. The petrochemical study show that the Nopal Rhyolite and Escuadra Rhyolite are the source of U and of hydrothermal solutions [fr

  1. In-situ tuff water migration/heater experiment: experimental plan

    International Nuclear Information System (INIS)

    Johnstone, J.K.

    1980-08-01

    Tuffs on the Nevada Test Site (NTS) are currently under investigation as a potential isolation medium for heat-producing nuclear wastes. The National Academy of Sciences has concurred in our identification of the potentially large water content (less than or equal to 40 vol %) of tuffs as one of the important issues affecting their suitability for a repository. This Experimental Plan describes an in-situ experiment intended as an initial assessment of water generation/migration in response to a thermal input. The experiment will be conducted in the Grouse Canyon Welded Tuff in Tunnel U12g (G-Tunnel) located in the north-central region of the NTS. While the Grouse Canyon Welded Tuff is not a potential repository medium, it has physical, thermal, and mechanical properties very similar to those tuffs currently under consideration and is accessible at depth (400 m below the surface) in an existing facility. Other goals of the experiment are to support computer-code and instrumentation development, and to measure in-situ thermal properties. The experimental array consists of a central electrical heater, 1.2 m long x 10.2 cm diameter, surrounded by three holes for measuring water-migration behavior, two holes for measuring temperature profiles, one hole for measuring thermally induced stress in the rock, and one hole perpendicular to the heater to measure displacement with a laser. This Experimental Plan describes the experimental objectives, the technical issues, the site, the experimental array, thermal and thermomechanical modeling results, the instrumentation, the data-acquisition system, posttest characterization, and the organizational details

  2. Hydrothermal interaction of solid wafers of Topopah Spring Tuff with J-13 water and distilled water at 90, 150, and 250{sup 0}C, using Dickson-type, gold-bag rocking autoclaves

    Energy Technology Data Exchange (ETDEWEB)

    Knauss, K.G.; Beiriger, W.J.; Peifer, D.W.; Piwinskii, A.J.

    1985-09-01

    The Nevada Nuclear Waste Storage Investigations Project has conducted experiments to study the hydrothermal interaction of rock and water representative of a potential high-level waste repository at Yucca Mountain, Nevada. The results of these experiments help define the near-field repository environment during and shortly after the thermal period that results from the emplacement of nuclear waste. When considered in conjunction with results contained in companion reports, these results can be used to assess our ability to accelerate tests using the surface area/volume parameter and/or temperature. These rock-water interaction experiments were conducted with solid polished wafers cut from both drillcore and outcrop samples of Topopah tuff, using both a natural ground water and distilled water as the reacting fluid. Pre- and post-test characterization of the reacting materials was extensive. Post-test identification and chemical analysis of secondary phases resulting from the hydrothermal interactions were aided by using monoliths of tuff rather than crushed material. All experiments were run in Dickson-type, gold-bag rocking autoclaves that were periodically sampled at in situ conditions. A total of nine short-term (up to 66-day) experiments were run in this series; these experiments covered the range from 90 to 250{sup 0}C and from 50 to 100 bar. The results obtained from the experiments have been used to evaluate the modeled results produced by calculations using the geochemical reaction process code EQ3/6. 31 refs., 37 figs., 7 tabs.

  3. Hydrothermal interaction of solid wafers of Topopah Spring Tuff with J-13 water and distilled water at 90, 150, and 2500C, using Dickson-type, gold-bag rocking autoclaves

    International Nuclear Information System (INIS)

    Knauss, K.G.; Beiriger, W.J.; Peifer, D.W.; Piwinskii, A.J.

    1985-09-01

    The Nevada Nuclear Waste Storage Investigations Project has conducted experiments to study the hydrothermal interaction of rock and water representative of a potential high-level waste repository at Yucca Mountain, Nevada. The results of these experiments help define the near-field repository environment during and shortly after the thermal period that results from the emplacement of nuclear waste. When considered in conjunction with results contained in companion reports, these results can be used to assess our ability to accelerate tests using the surface area/volume parameter and/or temperature. These rock-water interaction experiments were conducted with solid polished wafers cut from both drillcore and outcrop samples of Topopah tuff, using both a natural ground water and distilled water as the reacting fluid. Pre- and post-test characterization of the reacting materials was extensive. Post-test identification and chemical analysis of secondary phases resulting from the hydrothermal interactions were aided by using monoliths of tuff rather than crushed material. All experiments were run in Dickson-type, gold-bag rocking autoclaves that were periodically sampled at in situ conditions. A total of nine short-term (up to 66-day) experiments were run in this series; these experiments covered the range from 90 to 250 0 C and from 50 to 100 bar. The results obtained from the experiments have been used to evaluate the modeled results produced by calculations using the geochemical reaction process code EQ3/6. 31 refs., 37 figs., 7 tabs

  4. Frictional properties of jointed welded tuff

    International Nuclear Information System (INIS)

    Teufel, L.W.

    1981-07-01

    The results of the experiments on simulated joints in welded tuff from the Grouse Canyon Member of the Belted Range Tuff warrant the following conclusions: (1) The coefficient of friction of the joints is independent of normal stress at a given sliding velocity. (2) The coefficient of friction increases with both increasing time of stationary contact and decreasing sliding velocity. (3) Time and velocity dependence of friction is due to an increase in the real area of contact on the sliding surface, caused by asperity creep. (4) Joints in water-saturated tuff show a greater time and velocity dependence of friction than those in dehydrated tuff. (5) The enhanced time and velocity dependence of friction with water saturation is a result of increased creep at asperity contacts, which is in turn due to a reduction in the surface indentation hardness by hydrolytic weakening and/or stress corrosion cracking

  5. A strategy to seal exploratory boreholes in unsaturated tuff

    International Nuclear Information System (INIS)

    Fernandez, J.A.; Case, J.B.; Givens, C.A.; Carney, B.C.

    1994-04-01

    This report presents a strategy for sealing exploratory boreholes associated with the Yucca Mountain Site Characterization Project. Over 500 existing and proposed boreholes have been considered in the development of this strategy, ranging from shallow (penetrating into alluvium only) to deep (penetrating into the groundwater table). Among the comprehensive list of recommendations are the following: Those boreholes within the potential repository boundary and penetrating through the potential repository horizon are the most significant boreholes from a performance standpoint and should be sealed. Shallow boreholes are comparatively insignificant and require only nominal sealing. The primary areas in which to place seals are away from high-temperature zones at a distance from the potential repository horizon in the Paintbrush nonwelded tuff and the upper portion of the Topopah Spring Member and in the tuffaceous beds of the Calico Hills Unit. Seals should be placed prior to waste emplacement. Performance goals for borehole seals both above and below the potential repository are proposed. Detailed construction information on the boreholes that could be used for future design specifications is provided along with a description of the environmental setting, i.e., the geology, hydrology, and the in situ and thermal stress states. A borehole classification scheme based on the condition of the borehole wall in different tuffaceous units is also proposed. In addition, calculations are presented to assess the significance of the boreholes acting as preferential pathways for the release of radionuclides. Design calculations are presented to answer the concerns of when, where, and how to seal. As part of the strategy development, available technologies to seal exploratory boreholes (including casing removal, borehole wall reconditioning, and seal emplacement) are reviewed

  6. Reactivity of a tuff-bearing concrete: CL-40 CON-14

    International Nuclear Information System (INIS)

    Scheetz, B.E.; Roy, D.M.

    1989-04-01

    Samples of a tuff-bearing concrete have been altered in J-13 groundwater and in the vapor phase over deionized water at 200/degree/C. Crushed and intact discs of the concrete have been studied. The glassy tuff component of the tuff was more extensively reacted than the welded devitrified tuff. The original concrete was formulated to be expansive on curing through the formation of the calcium alumino-sulfate hydrate phase, ettringite. An x-ray diffraction examination of the altered crushed samples shows that the ettringite is no longer present. The original, poorly crystalline calcium-silicate-hydrate has recrystallized to tobermorite. In the rocking autoclave experiments with crushed material, which are the experiments expected to have the fastest reaction rates, the tobermorite has been replaced by a mineral of the gyrolite-truscottite group at the longer reaction times. The disc experiments in J-13 groundwater are characterized by prominent dissolution of the tuff aggregate. Alteration in the vapor phase experiments is primarily in the form of overgrowths on the discs. 10 refs., 27 figs., 12 tabs

  7. The behavior of biogenic silica-rich rocks and volcanic tuffs as pozzolanic additives in cement

    Science.gov (United States)

    Fragoulis, Dimitris; Stamatakis, Michael; Anastasatou, Marianthi

    2015-04-01

    Cements currently produced, include a variety of pozzolanic materials, aiming for lower clinker addition and utilization of vast deposits of certain raw materials and/or mining wastes and byproducts. The major naturally occurring pozzolanic materials include glassy tuffs, zeolitic tuffs, diatomites and volcanic lavas rich in glassy phase, such as perlites. Therefore, based on the available raw materials in different locations, the cement composition might vary according to the accessibility of efficient pozzolanic materials. In the present investigation, the behavior of pozzolanic cements produced with representative samples of the aforementioned materials was studied, following the characterization of the implemented pozzolanas with respect to their chemical and mineralogical characteristics. Laboratory cements were produced by co-grinding 75% clinker, 5% gypsum and 20% pozzolana, for the same period of time (45 min). Regarding pozzolanic materials, four different types of pozzolanas were utilized namely, diatomite, perlite, zeolite tuff and glassy tuff. More specifically, two diatomite samples originated from Australia and Greece, with high and low reactive silica content respectively, two perlite samples originated from Turkey and from Milos Island, Greece, with different reactive silica contents, a zeolite tuff sample originated from Turkey and a glassy tuff sample originated from Milos Island, Greece. The above pozzolana samples, which were ground in the laboratory ball mill for cement production performed differently during grinding and that was reflected upon the specific surface area (cm2/gr) values. The perlites and the glassy tuff were the hardest to grind, whereas, the zeolite tuff and the Australian diatomite were the easiest ones. However, the exceedingly high specific surface area of the Australian diatomite renders cement difficult to transport and tricky to use for concrete manufacturing, due to the high water demand of the cement mixture. Regarding

  8. Fluid flow and radionuclide transport in complex repository mines. Synthesis report part 1/2. Two-phase flow in a saline repository using the example ERAM; Fluidstroemung und Radionuklidtransport in komplexen Endlagerbergwerken. Synthesebericht Teil 1/2. Zweiphasenfluss in einem salinaren Endlager am Beispiel des ERAM

    Energy Technology Data Exchange (ETDEWEB)

    Kock, Ingo; Frieling, Gerd; Navarro, Martin

    2016-10-15

    The aim of the project is the understanding of two-phase flow processes in a complex final repository system. The consideration of two-phase flow processes for calculations concerning the modeled final repository system induces processes and effects that influence the fluid and radionuclide transport significantly. Two-phase flow processes cover not only capillary pressures and the relative permeability but also a basic competition of phases for the pore volume with respect to storage and transport and density driven vertical phase separation.

  9. Investigation of two-phase flow phenomena associated with corrosion in an SF/HLW repository in Opalinus Clay, Switzerland

    Energy Technology Data Exchange (ETDEWEB)

    Senger, R.; Marschall, P.; Finsterle, S.

    2008-08-04

    Gas generation from corrosion of the waste canisters and gas accumulation in the backfilled emplacement tunnels is a key issue in the assessment of long-term radiological safety of the proposed repository for spent fuel and high-level waste (SF/HLW) sited in the Opalinus Clay formation of Northern Switzerland. Previous modeling studies indicated a significant pressure buildup in the backfilled emplacement tunnels for those sensitivity runs, where corrosion rates were high and the permeability of the Opalinus Clay was very low. As an extension to those studies, a refined process model of the canister corrosion phenomena has been developed, which accounts not only for the gas generation but also for the water consumption associated with the chemical reaction of corrosion of steel under anaerobic conditions. The simulations with the new process model indicate, that with increasing corrosion rates and decreasing host-rock permeability, pressure buildup increased, as expected. However, the simulations taking into account water consumption show that the pressure buildup is reduced compared to the simulation considering only gas generation. The pressure reduction is enhanced for lower permeability of the Opalinus Clay and for higher corrosion rates, which correspond to higher gas generations rates and higher water consumption rates. Moreover, the simulated two-phase flow patterns in the engineered barrier system (EBS) and surrounding Opalinus Clay show important differences at late time of the gas production phase as the generated gas continues to migrate outward into the surrounding host rock. For the case without water consumption, the water flow indicates overall downward flow due to a change in the overall density of the gas-fluid mixture from that based on the initially prescribed hydrostatic pressure gradient. For the case with water consumption, water flow converges toward the waste canister at a rate corresponding to the water consumption rate associated with the

  10. Simulation approaches for the two-phase flow in saline repositories using the code TOUGH2-GRS. Report in the frame of the project ZIESEL. Two-phase flow in a saline repository using the example ERAM; Ansaetze zur Simulation der Zweiphasenstroemung in salinaren Endlagern mit dem Code TOUGH2-GRS. Bericht im Vorhaben ZIESEL. Zweiphasenfluss in einem salinaren Endlager am Beispiel des ERAM

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, Martin; Fischer, Heidemarie; Seher, Holger; Weyand, Torben

    2016-10-15

    The simulation approaches for the two-phase flow in saline repositories using the code TOUGH2-GRS cover the following issues: simulation of gravitational flows in horizontal galleries without vertical discretization, homogenization approach for the simulation of the two-phase flow in converging partly backfilled galleries, qualification of the convergence approach implemented by GRS into the code TOUGH2-GRS, discretization effects during replacement of liquid by gas, consequences for the system analyses in the frame of the project ZIESEL.

  11. The Public Repository of Xenografts (ProXe) enables discovery and randomized phase II-like trials in mice

    Science.gov (United States)

    Townsend, Elizabeth C.; Murakami, Mark A.; Christodoulou, Alexandra; Christie, Amanda L.; Köster, Johannes; DeSouza, Tiffany A.; Morgan, Elizabeth A.; Kallgren, Scott P.; Liu, Huiyun; Wu, Shuo-Chieh; Plana, Olivia; Montero, Joan; Stevenson, Kristen E.; Rao, Prakash; Vadhi, Raga; Andreeff, Michael; Armand, Philippe; Ballen, Karen K.; Barzaghi-Rinaudo, Patrizia; Cahill, Sarah; Clark, Rachael A.; Cooke, Vesselina G.; Davids, Matthew S.; DeAngelo, Daniel J.; Dorfman, David M.; Eaton, Hilary; Ebert, Benjamin L.; Etchin, Julia; Firestone, Brant; Fisher, David C.; Freedman, Arnold S.; Galinsky, Ilene A.; Gao, Hui; Garcia, Jacqueline S.; Garnache-Ottou, Francine; Graubert, Timothy A.; Gutierrez, Alejandro; Halilovic, Ensar; Harris, Marian H.; Herbert, Zachary T.; Horwitz, Steven M.; Inghirami, Giorgio; Intlekoffer, Andrew M.; Ito, Moriko; Izraeli, Shai; Jacobsen, Eric D.; Jacobson, Caron A.; Jeay, Sébastien; Jeremias, Irmela; Kelliher, Michelle A.; Koch, Raphael; Konopleva, Marina; Kopp, Nadja; Kornblau, Steven M.; Kung, Andrew L.; Kupper, Thomas S.; LaBoeuf, Nicole; LaCasce, Ann S.; Lees, Emma; Li, Loretta S.; Look, A. Thomas; Murakami, Masato; Muschen, Markus; Neuberg, Donna; Ng, Samuel Y.; Odejide, Oreofe O.; Orkin, Stuart H.; Paquette, Rachel R.; Place, Andrew E.; Roderick, Justine E.; Ryan, Jeremy A.; Sallan, Stephen E.; Shoji, Brent; Silverman, Lewis B.; Soiffer, Robert J.; Steensma, David P.; Stegmaier, Kimberly; Stone, Richard M.; Tamburini, Jerome; Thorner, Aaron R.; van Hummelen, Paul; Wadleigh, Martha; Wiesmann, Marion; Weng, Andrew P.; Wuerthner, Jens U.; Williams, David A.; Wollison, Bruce M.; Lane, Andrew A.; Letai, Anthony; Bertagnolli, Monica M.; Ritz, Jerome; Brown, Myles; Long, Henry; Aster, Jon C.; Shipp, Margaret A.; Griffin, James D.; Weinstock, David M.

    2016-01-01

    Summary Over 90% of drugs with preclinical activity fail in human trials, largely due to insufficient efficacy. We hypothesized that adequately powered trials of patient-derived xenografts (PDX) in mice could efficiently define therapeutic activity across heterogeneous tumors. To address this hypothesis, we established a large, publically available repository of well-characterized leukemia and lymphoma PDXs that undergo orthotopic engraftment called the Public Repository of Xenografts (PRoXe; www.proxe.org). PRoXe includes all de-identified information relevant to the primary specimens and the PDXs derived from them. Using this repository, we demonstrate that large studies of acute leukemia PDXs that mimic human randomized clinical trials can characterize drug efficacy and generate transcriptional, functional and proteomic biomarkers in both treatment-naïve and relapsed/refractory disease. PMID:27070704

  12. National Geoscience Data Repository System: Phase 2 -- Planning and pilot study. Progress report, 1. quarter, January--March 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-01

    The NGDRS goal is to preserve and make geoscience and engineering data readily accessible to those who have an interest in using such data. To achieve this goal requires the careful management of the process for transferring data from data providers to the public domain and the creation of the information systems organization and infrastructure to allow data consumers to find and access the data. This report describes the NGDRS organization structure; the development of a directory of existing geoscience data repositories; the financial models for data transfer (seismic data transfer, core data transfer, and data browser); and the overall architecture of the repository system.

  13. Thermal conductivity of silicic tuffs: predictive formalism and comparison with preliminary experimental results

    International Nuclear Information System (INIS)

    Lappin, A. R.

    1980-07-01

    Performance of both near- and far-field thermomechanical calculations to assess the feasibility of waste disposal in silicic tuffs requires a formalism for predicting thermal conductivity of a broad range of tuffs. This report summarizes the available thermal conductivity data for silicate phases that occur in tuffs and describes several grain-density and conductivity trends which may be expected to result from post-emplacement alteration. A bounding curve is drawn that predicts the minimum theoretical matrix (zero-porosity) conductivity for most tuffs as a function of grain density. Comparison of experimental results with this curve shows that experimental conductivities are consistently lower at any given grain density. Use of the lowered bounding curve and an effective gas conductivity of 0.12 W/m 0 C allows conservative prediction of conductivity for a broad range of tuff types. For the samples measured here, use of the predictive curve allows estimation of conductivity to within 15% or better, with one exception. Application and possible improvement of the formalism are also discussed

  14. Evidence for a welded tuff in the Rhyolite of Calico Hills

    International Nuclear Information System (INIS)

    Dickerson, R.P.; Hunter, W.C.

    1994-01-01

    A welded pyroclastic deposit has been identified in the Rhyolite of Calico Hills near Yucca Mountain, Nevada, where only lava flows and nonwelded pyroclastic deposits were previously described. Field data from Fortymile Wash show that nonwelded, bedded tuff grades upward into partially welded massive ruff, and thence into densely welded vitrophyre. Petrographic data show a progressive decrease in inter- and intragranular porosity and amount of vapor-phase minerals, with increasing welding. Pumice fragments are first deformed, then develop diffuse boundaries which become increasingly obscure with progressive welding. The most densely welded rock is a perlitic vitrophyre. The origin of this welded tuff is not clear, as it could represent an ignimbrite or a tuff fused beneath a thick lava flow

  15. Use of Rhenish tuff in the Netherlands

    NARCIS (Netherlands)

    Nijland, T.G.; Hees, R.P.J. van

    2006-01-01

    Rhenish tuffs (Rmer, Weiberner / Hohenleie, Et-tringer / Hasenstoppler) from the volcanic Eifel re-gion, Germany, have widely been used as building stone in the Netherlands. In the present paper, an overview is given of their historic use in the Nether-lands, the experience with weathering, the

  16. Repository exploration

    International Nuclear Information System (INIS)

    Pentz, D.L.

    1984-01-01

    This paper discusses exploration objectives and requirements for a nuclear repository in the U.S.A. The importance of designing the exploration program to meet the system performance objectives is emphasized and some examples of the extent of exploration required before the License Application for Construction Authorization is granted are also discussed

  17. A performance assessment methodology for high-level radioactive waste disposal in unsaturated, fractured tuff

    International Nuclear Information System (INIS)

    Gallegos, D.P.

    1991-07-01

    Sandia National Laboratories, has developed a methodology for performance assessment of deep geologic disposal of high-level nuclear waste. The applicability of this performance assessment methodology has been demonstrated for disposal in bedded salt and basalt; it has since been modified for assessment of repositories in unsaturated, fractured tuff. Changes to the methodology are primarily in the form of new or modified ground water flow and radionuclide transport codes. A new computer code, DCM3D, has been developed to model three-dimensional ground-water flow in unsaturated, fractured rock using a dual-continuum approach. The NEFTRAN 2 code has been developed to efficiently model radionuclide transport in time-dependent velocity fields, has the ability to use externally calculated pore velocities and saturations, and includes the effect of saturation dependent retardation factors. In order to use these codes together in performance-assessment-type analyses, code-coupler programs were developed to translate DCM3D output into NEFTRAN 2 input. Other portions of the performance assessment methodology were evaluated as part of modifying the methodology for tuff. The scenario methodology developed under the bedded salt program has been applied to tuff. An investigation of the applicability of uncertainty and sensitivity analysis techniques to non-linear models indicate that Monte Carlo simulation remains the most robust technique for these analyses. No changes have been recommended for the dose and health effects models, nor the biosphere transport models. 52 refs., 1 fig

  18. Integrated account of method, site selection and programme prior to the site investigation phase[Planning for a Swedish repository for spent nuclear fuels

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-12-01

    In order to dispose of the spent nuclear fuel in a safe manner, SKB plans to site a deep repository and an encapsulation plant with associated canister fabrication and transportation system. After an integrated evaluation of feasibility studies and other material, SKB will proceed with investigations of the rock and studies regarding establishment of the deep disposal system in the municipality of Oskarshamn or in Northern Uppland. The plans also include further study of the prospects for a deep repository in the municipality of Nykoeping. In the municipality of Oskarshamn, SKB plans further studies of a siting of the deep repository at Simpevarp. There SKB wants to initiate site investigations with test drilling. For the encapsulation plant, SKB wants to continue studying a siting at CLAB. In Northern Uppland, SKB plans to study two siting alternatives for the deep repository. One is Forsmark in the municipality of Oesthammar, where SKB wants to initiate a site investigation with test drilling. The other is Tierp north of Skutskaer, where SKB intends to start test drilling in an area north of Tierp. First, however, a suitable drilling area with possible transport solutions needs to be defined. This alternative requires the participation of the municipalities of both Tierp and Aelvkarleby. A siting of the encapsulation plant in Northern Uppland will also be studied. For the municipality of Nykoeping, SKB plans to conduct a new safety assessment for the Fjaellveden area, based on data from previous investigations as well as additional studies of how a deep repository could be arranged. SKB will thereby gather data from yet another geographic and geological region beyond those that are prioritized. No test drilling is planned in Nykoeping. The goal of the site investigation phase is to obtain all permits needed to build the planned facilities. It will take an estimated 7 - 8 years to assemble the requisite supporting material, carry out consultations, compile siting

  19. Rock support for nuclear waste repositories

    International Nuclear Information System (INIS)

    Abramson, L.W.; Schmidt, B.

    1984-01-01

    The design of rock support for underground nuclear waste repositories requires consideration of special construction and operation requirements, and of the adverse environmental conditions in which some of the support is placed. While repository layouts resemble mines, design, construction and operation are subject to quality assurance and public scrutiny similar to what is experienced for nuclear power plants. Exploration, design, construction and operation go through phases of review and licensing by government agencies as repositories evolve. This paper discusses (1) the various stages of repository development; (2) the environment that supports must be designed for; (3) the environmental effects on support materials; and (4) alternative types of repository rock support

  20. Arsenogoyazite in Cenozoic volcanic tuff at Tabalaopa Basin, Chihuahua, Mexico

    Science.gov (United States)

    Ren, M.; Rodriguez, A.; Goodell, P.

    2012-12-01

    Arsenogoyazite has been identified in Cenozoic volcanic tuff at Tabalaopa Basin, Chihuahua, Mexico. Tabalaopa Basin contains volcanic strata and the unconsolidated Quaternary deposit. Cenozoic volcanic tuff forms the low hill terrene in this area. It is a major reservoir for the City of Chihuahua groundwater. Arsenic anomaly (more than 20 ppb) has been observed at El Mimbre, northeast of the city. The exposed reddish color volcanic rocks are felsic welded tuff and rhyolite. Sanidine, quartz, and biotite phenocrysts show linear distribution within the fine grain matrix. The rocks contain large amount of vesicles which are lineated with the welding bends. White and colorless microsize crystals formed on the well of the cavities and the majority of them are K-feldspar. Quartz, Ti-magnetite, and arsenogoyazite are coexisting with feldspars. The sizes of the crystals in the cavities are 10 to several 10s of micrometers. The arsenic x-ray maps have been collected for the rock sections to locate the arsenic minerals. The crystals in cavities show euhedral shape. Most arsenic containing crystals have a near cubic form with triangle surfaces at some corners. The high resolution field-emission SEM images have been collected to study the symmetry of the crystals. EDS spectra for the high arsenic phases show three major elements As-Al-Sr and also minor amount of P-S-REE-Ca-Fe-Si. Since the arsenic minerals are growing on the wall of the vesicle, it is difficult to perform good electron microprobe analysis. Some primary microprobe data give following results in weight percent: SrO 11.8-13.1, CaO 0.2-0.3, FeO 0.3-0.5, Al2O3 28.6-30.9, La2O3 2.4-2.5, Ce2O3 2.3-.24, SiO2 1.1-3.6, As2O5 32.4-35.2, P2O5 1.7-1.9, SO3 0.8-1.4. This chemistry is similar to the reported arsenogoyazite chemical data. So this high arsenic phase is identified as arsenogoyazite. The arsenic anomaly in groundwater at El Mimbre, Chihuahua should be contributed from this arsenic mineral phase in the strata.

  1. Plutonium speciation in selected basalt, granite, shale, and tuff ground waters

    International Nuclear Information System (INIS)

    Cleveland, J.M.; Nash, K.L.; Rees, T.F.

    1983-01-01

    The speciation of added plutonium was determined in ground waters of widely varying composition from four rock types: basalt, granite, shale, and tuff. Plutonium was soluble in the basalt water, which contained a high fluoride ion concentration, probably as a result of its stabilization in solution as fluorocomplexes, primarily of plutonium (IV); it was insoluble, however, in the shale ground water, which contained the highest concentration of sulfate ion. Results were intermediate in the granite and tuff ground waters. In synthetic waters containing significant concentrations of both sulfate and fluoride, the effects were smaller and less predictable. Dissolved oxygen, ionic strength, carbonate ion concentration, and pH had little effect on plutonium speciation in the ranges encountered in this study. However, other ionic species not involved in this study may also influence plutonium speciation. The results have potential significance in establishing site-selection criteria for radioactive waste repositories. All other factors being equal, host rocks whose associated waters contain low concentrations of free fluoride ion should be preferable for the location of waste repositories

  2. THERMAL CONDUCTIVITY OF NON-REPOSITORY LITHOSTRATIGRAPHIC LAYERS

    International Nuclear Information System (INIS)

    R. JONES

    2004-01-01

    This model report addresses activities described in ''Technical Work Plan for: Near-Field Environment and Transport Thermal Properties and Analysis Reports Integration'' (BSC 2004 [DIRS 171708]). The model develops values for thermal conductivity, and its uncertainty, for the nonrepository layers of Yucca Mountain; in addition, the model provides estimates for matrix porosity and dry bulk density for the nonrepository layers. The studied lithostratigraphic units, as identified in the ''Geologic Framework Model'' (GFM 2000) (BSC 2004 [DIRS 170029]), are the Timber Mountain Group, the Tiva Canyon Tuff, the Yucca Mountain Tuff, the Pah Canyon Tuff, the Topopah Spring Tuff (excluding the repository layers), the Calico Hills Formation, the Prow Pass Tuff, the Bullfrog Tuff, and the Tram Tuff. The deepest model units of the GFM (Tund and Paleozoic) are excluded from this study because no data suitable for model input are available. The parameter estimates developed in this report are used as input to various models and calculations that simulate heat transport through the rock mass. Specifically, analysis model reports that use product output from this report are: (1) Drift-scale coupled processes (DST and TH seepage) models; (2) Drift degradation analysis; (3) Multiscale thermohydrologic model; and (4) Ventilation model and analysis report. In keeping with the methodology of the thermal conductivity model for the repository layers in ''Thermal Conductivity of the Potential Repository Horizon'' (BSC 2004 [DIRS 169854]), the Hsu and others (1995 [DIRS 158073]) three-dimensional (3-D) cubic model (referred to herein as ''the Hsu model'') was used to represent the matrix thermal conductivity as a function of the four parameters (matrix porosity, thermal conductivity of the saturating fluid, thermal conductivity of the solid, and geometric connectivity of the solid). The Hsu model requires input data from each test specimen to meet three specific conditions: (1) Known value

  3. THERMAL CONDUCTIVITY OF NON-REPOSITORY LITHOSTRATIGRAPHIC LAYERS

    Energy Technology Data Exchange (ETDEWEB)

    R. JONES

    2004-10-22

    This model report addresses activities described in ''Technical Work Plan for: Near-Field Environment and Transport Thermal Properties and Analysis Reports Integration'' (BSC 2004 [DIRS 171708]). The model develops values for thermal conductivity, and its uncertainty, for the nonrepository layers of Yucca Mountain; in addition, the model provides estimates for matrix porosity and dry bulk density for the nonrepository layers. The studied lithostratigraphic units, as identified in the ''Geologic Framework Model'' (GFM 2000) (BSC 2004 [DIRS 170029]), are the Timber Mountain Group, the Tiva Canyon Tuff, the Yucca Mountain Tuff, the Pah Canyon Tuff, the Topopah Spring Tuff (excluding the repository layers), the Calico Hills Formation, the Prow Pass Tuff, the Bullfrog Tuff, and the Tram Tuff. The deepest model units of the GFM (Tund and Paleozoic) are excluded from this study because no data suitable for model input are available. The parameter estimates developed in this report are used as input to various models and calculations that simulate heat transport through the rock mass. Specifically, analysis model reports that use product output from this report are: (1) Drift-scale coupled processes (DST and TH seepage) models; (2) Drift degradation analysis; (3) Multiscale thermohydrologic model; and (4) Ventilation model and analysis report. In keeping with the methodology of the thermal conductivity model for the repository layers in ''Thermal Conductivity of the Potential Repository Horizon'' (BSC 2004 [DIRS 169854]), the Hsu et al. (1995 [DIRS 158073]) three-dimensional (3-D) cubic model (referred to herein as ''the Hsu model'') was used to represent the matrix thermal conductivity as a function of the four parameters (matrix porosity, thermal conductivity of the saturating fluid, thermal conductivity of the solid, and geometric connectivity of the solid). The Hsu model requires input data

  4. Effect of volcanic tuff on the characteristics of cement mortar

    Directory of Open Access Journals (Sweden)

    Jehad Al-Zou'by

    2014-06-01

    Full Text Available This paper examines how Jordanian volcanic tuff aggregates affect the characteristics of cement mortar. Five mortar mixes were prepared by replacing normal aggregate (standard sand with volcanic tuff aggregate in ratios of 0, 25, 50, 75, and 100% (M1 to M5, respectively. Compressive strength, flexural strength, and unit weight were tested at mortar ages of 3, 7, 28, and 56 days. The results revealed improved compressive and flexural strength, which were maximal for the M3 sample. Unit weight decreased as the ratio of volcanic tuff increased. Based on these results, adding Jordanian volcanic tuff in the appropriate ratio will improve these mortar characteristics.

  5. Learning Object Repositories

    Science.gov (United States)

    Lehman, Rosemary

    2007-01-01

    This chapter looks at the development and nature of learning objects, meta-tagging standards and taxonomies, learning object repositories, learning object repository characteristics, and types of learning object repositories, with type examples. (Contains 1 table.)

  6. Summary of sorption measurements performed with Yucca Mountain, Nevada, tuff samples and water from Well J-13

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, K.W.

    1987-12-01

    The sorption studies undertaken from 1977 to 1985 by Los Alamos National Laboratory in support of the Nevada Nuclear Waste Storage Investigations project are summarized, and the data are tabulated in the Appendix. These studies of the sorptive behavior of Yucca Mountain, Nevada, area tuffs have been partly generic in nature (to understand the sorptive behavior of tuff as a function of many variables) and partly site specific (to obtain data for a possible repository site at Yucca Mountain). Sorption has been investigated as a function of mineralogy, temperature, particle size, waste-element concentration, water composition, sorption time, and other variables. The major elements studied were americium, cesium, neptunium, plutoniuim, thorium, uranium, strontium, technetium, tin, barium, radium, cerium, europium, and selenium. 24 refs., 2 figs., 10 tabs.

  7. Geologic evaluation of six nonwelded tuff sites in the vicinity of Yucca Mountain, Nevada for a surface-based test facility for the Yucca Mountain Project

    International Nuclear Information System (INIS)

    Broxton, D.E.; Chipera, S.J.; Byers, F.M. Jr.; Rautman, C.A.

    1993-10-01

    Outcrops of nonwelded tuff at six locations in the vicinity of Yucca Mountain, Nevada, were examined to determine their suitability for hosting a surface-based test facility for the Yucca Mountain Project. Investigators will use this facility to test equipment and procedures for the Exploratory Studies Facility and to conduct site characterization field experiments. The outcrops investigated contain rocks that include or are similar to the tuffaceous beds of Calico Hills, an important geologic and hydrologic barrier between the potential repository and the water table. The tuffaceous beds of Calico Hills at the site of the potential repository consist of both vitric and zeolitic tuffs, thus three of the outcrops examined are vitric tuffs and three are zeolitic tuffs. New data were collected to determine the lithology, chemistry, mineralogy, and modal petrography of the outcrops. Some preliminary data on hydrologic properties are also presented. Evaluation of suitability of the six sites is based on a comparison of their geologic characteristics to those found in the tuffaceous beds of Calico Hills within the exploration block

  8. DECOVALEX - Mathematical models of coupled T-H-M processes for nuclear waste repositories. Report of phase III

    International Nuclear Information System (INIS)

    Jing, L.; Rutqvist, J.; Stephansson, O.

    1995-12-01

    This report presents the methodologies and results of the field/laboratory experiments and mathematical modeling defined for the phase III of the project. Results from test cases 2-6 are given in separate chapters of the report (which have been indexed separately), and the last chapter discusses the lessons learned from the three phases of the DECOVALEX project

  9. The Tala Tuff, La Primavera caldera Mexico. Pre-eruptive conditions and magma processes before eruption

    Science.gov (United States)

    Sosa-Ceballos, G.

    2015-12-01

    La Primavera caldera, Jalisco Mexico, is a Pleistocenic volcanic structure formed by dome complexes and multiple pyroclastic flows and fall deposits. It is located at the intersection of the Chapala, Colima, and Tepic grabens in western Mexico. The first volcanic activity associated to La Primavera started ~0.1 Ma with the emission of pre-caldera lavas. The caldera collapse occurred 95 ka and is associated to the eruption of ~20 km3of pumice flows known as the Tala tuff (Mahood 1980). The border of the caldera was replaced by a series of domes dated in 75-30 ky, which partially filled the inner depression of the caldera with pyroclastic flows and falls. For more than a decade the Federal Commission of Electricity in Mexico (CFE) has prospected and evaluated the geothermal potential of the Cerritos Colorados project at La Primavera caldera. In order to better understand the plumbing system that tapped the Tala tuff and to investigate its relation with the potential geothermal field at La Primavera we performed a series of hydrothermal experiments and studied melt inclusions hosted in quartz phenocrysts by Fourier Infra red stectroscopy (FTIR). Although some post caldera products at La Primavera contain fayalite and quartz (suggesting QFM conditions) the Tala tuff does not contain fayalite and we ran experiments under NNO conditions. The absence of titanomagnetite does not allowed us to calculate pre-eruptive temperature. However, the stability of quartz and plagioclase, which are natural phases, suggest that temperature should be less than 750 °C at a pressure of 200 MPa. The analyses of H2O and CO2 dissolved in melt inclusions yielded concentrations of 2-5 wt.% and 50-100 ppm respectively. This data confirm that the pre-eruptive pressure of the Tala tuff is ~200 MPa and in addition to major elements compositions suggest that the Tala tuff is either, compositionally zoned or mixed with other magma just prior to eruption.

  10. Update report on fracture flow in saturated tuff: Dynamic transport task for the Nevada Nuclear Waste Investigations

    International Nuclear Information System (INIS)

    Janecky, D.R.; Rundberg, R.S.; Ott, M.; Mitchell, A.

    1990-11-01

    This report summarizes the results of continuing experiments on the behavior of tracers during fracture flow in saturated, welded tuff. These experiments were completed during the past year as part of the Dynamic Transport Task of geochemical investigations for the Yucca Mountain Project sponsored by the US Department of Energy. These experiments are designed to investigate the effects of fluid movement in fractures when coupled with matrix diffusion and sorption but isolated from the effects of capillary suction and two-phase flow characteristic of unsaturated conditions. The experiments reported here are continuations of experimental efforts reported previously. The behavior of three tracers [HTO (tritiated water), TcO 4 - (pertechnetate), and sulforhodamine B dye] have been investigated during flow through a saturated column of densely welded tuff from the Topopah Spring Member of the Paintbrush Tuff, Yucca Mountain, Nye County, southern Nevada. 31 refs., 26 figs., 2 tabs

  11. Stratigraphic relations and hydrologic properties of the Paintbrush Tuff (PTn) hydrologic unit, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Moyer, T.C.; Geslin, J.K.; Flint, L.E.

    1996-01-01

    Yucca Mountain is being investigated as a potential site for a high- level nuclear waste repository. The intent of this study was to clarify stratigraphic relations within the Paintbrush Tuff (PTn) unit at Yucca Mountain in order to better understand vertical and lateral variations in hydrologic properties as they relate to the lithologic character of these rocks. This report defines informal stratigraphic units within the PTn interval, demonstrates their lateral continuity in the Yucca Mountain region, describes later and vertical variations within them, and characterizes their hydrologic properties and importance to numerical flow and transport models. We present tables summarizing the depth to stratigraphic contacts in cored borehole studies, and unit descriptions and correlations in 10 measured sections

  12. Stratigraphic relations and hydrologic properties of the Paintbrush Tuff (PTn) hydrologic unit, Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, T.C.; Geslin, J.K. [Science Applications International Corp., Golden, CO (United States); Flint, L.E. [U.S. Geological Survey, Yucca Mountain Project, Mercury, NV (United States)

    1996-08-01

    Yucca Mountain is being investigated as a potential site for a high- level nuclear waste repository. The intent of this study was to clarify stratigraphic relations within the Paintbrush Tuff (PTn) unit at Yucca Mountain in order to better understand vertical and lateral variations in hydrologic properties as they relate to the lithologic character of these rocks. This report defines informal stratigraphic units within the PTn interval, demonstrates their lateral continuity in the Yucca Mountain region, describes later and vertical variations within them, and characterizes their hydrologic properties and importance to numerical flow and transport models. We present tables summarizing the depth to stratigraphic contacts in cored borehole studies, and unit descriptions and correlations in 10 measured sections.

  13. Salt repository project closeout status report

    International Nuclear Information System (INIS)

    1988-06-01

    This report provides an overview of the scope and status of the US Department of Energy (DOE's) Salt Repository Project (SRP) at the time when the project was terminated by the Nuclear Waste Policy Amendments Act of 1987. The report reviews the 10-year program of siting a geologic repository for high-level nuclear waste in rock salt formations. Its purpose is to aid persons interested in the information developed during the course of this effort. Each area is briefly described and the major items of information are noted. This report, the three salt Environmental Assessments, and the Site Characterization Plan are the suggested starting points for any search of the literature and information developed by the program participants. Prior to termination, DOE was preparing to characterize three candidate sites for the first mined geologic repository for the permanent disposal of high-level nuclear waste. The sites were in Nevada, a site in volcanic tuff; Texas, a site in bedded salt (halite); and Washington, a site in basalt. These sites, identified by the screening process described in Chapter 3, were selected from the nine potentially acceptable sites shown on Figure I-1. These sites were identified in accordance with provisions of the Nuclear Waste Policy Act of 1982. 196 refs., 21 figs., 11 tabs

  14. Salt repository project closeout status report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1988-06-01

    This report provides an overview of the scope and status of the US Department of Energy (DOE`s) Salt Repository Project (SRP) at the time when the project was terminated by the Nuclear Waste Policy Amendments Act of 1987. The report reviews the 10-year program of siting a geologic repository for high-level nuclear waste in rock salt formations. Its purpose is to aid persons interested in the information developed during the course of this effort. Each area is briefly described and the major items of information are noted. This report, the three salt Environmental Assessments, and the Site Characterization Plan are the suggested starting points for any search of the literature and information developed by the program participants. Prior to termination, DOE was preparing to characterize three candidate sites for the first mined geologic repository for the permanent disposal of high-level nuclear waste. The sites were in Nevada, a site in volcanic tuff; Texas, a site in bedded salt (halite); and Washington, a site in basalt. These sites, identified by the screening process described in Chapter 3, were selected from the nine potentially acceptable sites shown on Figure I-1. These sites were identified in accordance with provisions of the Nuclear Waste Policy Act of 1982. 196 refs., 21 figs., 11 tabs.

  15. Geologic environments for nuclear waste repositories

    Directory of Open Access Journals (Sweden)

    Paleologos Evan K.

    2017-01-01

    Full Text Available High-level radioactive waste (HLW results from spent reactor fuel and reprocessed nuclear material. Since 1957 the scientific consensus is that deep geologic disposal constitutes the safest means for isolating HLW for long timescales. Nuclear power is becoming significant for the Arab Gulf countries as a way to diversify energy sources and drive economic developments. Hence, it is of interest to the UAE to examine the geologic environments currently considered internationally to guide site selection. Sweden and Finland are proceeding with deep underground repositories mined in bedrock at depths of 500m, and 400m, respectively. Equally, Canada’s proposals are deep burial in the plutonic rock masses of the Canadian Shield. Denmark and Switzerland are considering disposal of their relative small quantities of HLW into crystalline basement rocks through boreholes at depths of 5,000m. In USA, the potential repository at Yucca Mountain, Nevada lies at a depth of 300m in unsaturated layers of welded volcanic tuffs. Disposal of low and intermediate-level radioactive wastes, as well as the German HLW repository favour structurally-sound layered salt stata and domes. Our article provides a comprehensive review of the current concepts regarding HLW disposal together with some preliminary analysis of potentially appropriate geologic environments in the UAE.

  16. Repository performance confirmation

    International Nuclear Information System (INIS)

    Hansen, Francis D.

    2011-01-01

    Repository performance confirmation links the technical bases of repository science and societal acceptance. This paper explores the myriad aspects of what has been labeled performance confirmation in U.S. programs, which involves monitoring as a collection of distinct activities combining technical and social significance in radioactive waste management. This paper is divided into four parts: (1) A distinction is drawn between performance confirmation monitoring and other testing and monitoring objectives; (2) A case study illustrates confirmation activities integrated within a long-term testing and monitoring strategy for Yucca Mountain; (3) A case study reviews compliance monitoring developed and implemented for the Waste Isolation Pilot Plant; and (4) An approach for developing, evaluating and implementing the next generation of performance confirmation monitoring is presented. International interest in repository monitoring is exhibited by the European Commission Seventh Framework Programme 'Monitoring Developments for Safe Repository Operation and Staged Closure' (MoDeRn) Project. The MoDeRn partners are considering the role of monitoring in a phased approach to the geological disposal of radioactive waste. As repository plans advance in different countries, the need to consider monitoring strategies within a controlled framework has become more apparent. The MoDeRn project pulls together technical and societal experts to assimilate a common understanding of a process that could be followed to develop a monitoring program. A fundamental consideration is the differentiation of confirmation monitoring from the many other testing and monitoring activities. Recently, the license application for Yucca Mountain provided a case study including a technical process for meeting regulatory requirements to confirm repository performance as well as considerations related to the preservation of retrievability. The performance confirmation plan developed as part of the

  17. Report on static hydrothermal alteration studies of Topopah Spring tuff waters in J-13 water at 150{sup 0}C

    Energy Technology Data Exchange (ETDEWEB)

    Knauss, K.G.; Beiriger, W.B.

    1984-08-31

    This report presents the results of preliminary experimental work done to define the package environment in a potential nuclear waste repository in the Topopah Spring Member of the Paintbrush Tuff. The work is supported by the Nevada Nuclear Waste Storage Investigations (NNWSI) Project as a part of the Waste Package task to design a package suitable for waste storage within volcanic units at the Nevada Test Site. Static hydrothermal alteration experiments were run for 4 months using polished wafers either fully submerged in an appropriate natural ground water or exposed to water-saturated air with enough excess water to allow refluxing. The aqueous results agreed favorably with similar experiments run using crushed tuff, and the use of solid polished wafers allowed us to directly evaluate the effects of reaction on the tuff. The results are preliminary in the sense that these experiments were run in Teflon-lined, static autoclaves, whereas subsequent experiments have been run in Dickson-type gold-cell rocking autoclaves. The results predict relatively minor changes in water chemistry, very minor alteration of the host rock, and the production of slight amounts of secondary minerals, when liquid water could return to the rock pores following the temperature maximum during the thermal period. 7 references, 16 figures, 10 tables.

  18. Geohydrology of volcanic tuff penetrated by test well UE-25b#1, Yucca Mountain, Nye County, Nevada

    Science.gov (United States)

    Lahoud, R.G.; Lobmeyer, D.H.; Whitfield, M.S.

    1984-01-01

    Test well UE-25bNo1, located on the east side of Yucca Mountain in the southwestern part of the Nevada Test Site, was drilled to a total depth of 1,220 meters and hydraulically tested as part of a program to evaluate the suitability of Yucca Mountain as a nuclear-waste repository. The well penetrated almost 46 meters of alluvium and 1,174 meters of Tertiary volcanic tuffs. The composite hydraulic head for aquifers penetrated by the well was 728.9 meters above sea level (471.4 meters below land surface) with a slight decrease in loss of hydraulic head with depth. Average hydraulic conductivities for stratigraphic units determined from pumping tests, borehole-flow surveys, and packer-injection tests ranged from less than 0.001 meter per day for the Tram Member of the Crater Flat Tuff to 1.1 meters per day for the Bullfrog Member of the Crater Flat Tuff. The small values represented matrix permeability of unfractured rock; the large values probably resulted from fracture permeability. Chemical analyses indicated that the water is a soft sodium bicarbonate type, slightly alkaline, with large concentrations of dissolved silica and sulfate. Uncorrected carbon-14 age dates of the water were 14,100 and 13,400 years. (USGS)

  19. Preliminary numerical modeling for the G-Tunnel welded tuff mining experiment; Yucca Mountain site characterization project

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, R.L.; Bauer, S.J.

    1991-09-01

    Yucca Mountain, located in Southern Nevada, is to be considered as a potential site for a nuclear waste repository. Located in Rainier Mesa on the Nevada Test Site, G-Tunnel has been the site of a series of experiments, part of whose purpose is to evaluate measurement techniques for rock mechanics before testing in the Exploratory Shaft. Rainier Mesa is composed of welded and nonwelded tuffs that have thermal and mechanical properties and stress states similar to those of tuffs expected to be encountered at Yucca Mountain. A series of finite element calculations were performed to aid in designing instrumentation for the experiments in G-Tunnel and later to correlate with measured data. In this report are presented the results of the preliminary finite element calculations performed in conjunction with experimental measurements of drift convergence, or closure, and rock mass relaxation zones made before, during, and after completing the welded tuff mining experiment in G-Tunnel. Tape extensometer measurements of drift convergences and measurements determined by multiple point borehole extensometers are compared with corresponding calculated values using linear elastic and jointed rock material models. 9 refs., 25 figs., 7 tabs.

  20. Neptunium retardation with tuffs and groundwaters from Yucca Mountain

    International Nuclear Information System (INIS)

    Triay, I.R.; Robinson, B.A.; Lopez, R.M.; Mitchell, A.J.; Overly, C.M.

    1993-01-01

    The retardation of neptunium was studied using batch sorption and column techniques. Pure mineral separates, tuffs and groundwaters from Yucca Mountain were used for these experiments. Our results indicate that Np sorption increases rapidly as the pH of the water increases in cases where surface complexation is thought w be the dominant sorption mechanism. Oxide minerals (such as hematite) sorb Np strongly; therefore, these minerals even at trace levels in Yucca Mountain tuffs can result in significant Np retardation. Neptunium in groundwaters from Yucca Mountain exhibited a significant amount of sorption onto quartz. Neptunium sorption onto quartz is important because of the large quantity of silica in the tuffs. Elution of neptunium solutions in groundwater through columns made of crushed tuff yielded sorption coefficients that agree with the sorption results obtained using batch sorption techniques. Agreement between batch and column experiments indicates a neptunium sorption mechanism that is linear, reversible, and instantaneous

  1. Breast Cancer Tissue Repository

    National Research Council Canada - National Science Library

    Iglehart, J

    1997-01-01

    The Breast Tissue Repository at Duke enters its fourth year of finding. The purpose of the Repository at Duke is to provide substantial quantities of frozen tissue for explorative molecular studies...

  2. A strategy to seal exploratory boreholes in unsaturated tuff; Yucca Mountain Site Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, J.A. [Sandia National Labs., Albuquerque, NM (United States); Case, J.B.; Givens, C.A.; Carney, B.C. [IT Corp., Albuquerque, NM (United States)

    1994-04-01

    This report presents a strategy for sealing exploratory boreholes associated with the Yucca Mountain Site Characterization Project. Over 500 existing and proposed boreholes have been considered in the development of this strategy, ranging from shallow (penetrating into alluvium only) to deep (penetrating into the groundwater table). Among the comprehensive list of recommendations are the following: Those boreholes within the potential repository boundary and penetrating through the potential repository horizon are the most significant boreholes from a performance standpoint and should be sealed. Shallow boreholes are comparatively insignificant and require only nominal sealing. The primary areas in which to place seals are away from high-temperature zones at a distance from the potential repository horizon in the Paintbrush nonwelded tuff and the upper portion of the Topopah Spring Member and in the tuffaceous beds of the Calico Hills Unit. Seals should be placed prior to waste emplacement. Performance goals for borehole seals both above and below the potential repository are proposed. Detailed construction information on the boreholes that could be used for future design specifications is provided along with a description of the environmental setting, i.e., the geology, hydrology, and the in situ and thermal stress states. A borehole classification scheme based on the condition of the borehole wall in different tuffaceous units is also proposed. In addition, calculations are presented to assess the significance of the boreholes acting as preferential pathways for the release of radionuclides. Design calculations are presented to answer the concerns of when, where, and how to seal. As part of the strategy development, available technologies to seal exploratory boreholes (including casing removal, borehole wall reconditioning, and seal emplacement) are reviewed.

  3. Radionuclide Migration Experiments in Tuff Blocks/Underunsaturated and Saturated Conditions at a Scale of Up to 1 Metre

    Energy Technology Data Exchange (ETDEWEB)

    Vandergraaf, T. T.; Drew, D. J.; Ticknor, K. V.; Hamon, C. J.; Seddon, W. A.

    2003-02-25

    To complement migration experiments with non-radioactive tracers in the Busted Butte experimental facility (BBTF) at the Nevada Test Site, an exploratory migration experiment has been performed under unsaturated conditions in a {approx}0.3m x {approx}0.3m x {approx}0.3m block of tuff. Longer term migration experiments, up to 600 days, under unsaturated and saturated conditions in {approx}1 m3 blocks of tuff have recently been completed. Na-fluorescein, 3H (as tritiated water), 22Na, 60Co, 95mTc and/or 99Tc (as the pertechnetate anion), 137Cs, and 237Np were used as tracers in all three experiments. Under unsaturated conditions, Tc is transported slightly faster than 3H, while under saturated conditions, the chemical conditions became highly reducing, leading to significant retardation of Tc along the flow field. If chemically reducing conditions can be demonstrated to exist in the saturated zone downstream from the proposed repository, the geological formations underlying the proposed repository horizon can potentially act as a geological barrier to the transport of some multivalent radionuclides.

  4. Photon Shielding Features of Quarry Tuff

    Directory of Open Access Journals (Sweden)

    Vega-Carrillo Hector Rene

    2017-01-01

    Full Text Available Cantera is a quarry tuff widely used in the building industry; in this work the shielding features of cantera were determined. The shielding characteristics were calculated using XCOM and MCNP5 codes for 0.03, 0.07, 0.1, 0.3, 0.662, 1, 2, and 3 MeV photons. With XCOM the mass interaction coefficients, and the total mass attenuation coefficients, were calculated. With the MCNP5 code a transmission experiment was modelled using a point-like source located 42 cm apart from a point-like detector. Between the source and the detector, cantera pieces with different thickness, ranging from 0 to 40 cm were included. The collided and uncollided photon fluence, the Kerma in air and the Ambient dose equivalent were estimated. With the uncollided fluence the linear attenuation coefficients were determined and compared with those calculated with XCOM. The linear attenuation coefficient for 0.662 MeV photons was compared with the coefficient measured with a NaI(Tl-based γ-ray spectrometer and a 137Cs source.

  5. Evaluation of three Italian tuffs (Neapolitan Yellow Tuf, Tufo Romano and Tufo Etrusco) as compatible replacement stone for Römer tuff in Dutch built cultural heritage

    NARCIS (Netherlands)

    Nijland, T.G.; Hees, R.P.J. van; Bolondi, L.

    2010-01-01

    Rhenish tuffs from the volcanic Eifel region in Germany, in particular the so-called Römer tuff, are among the most prominent and voluminous natural stones in Dutch monuments. The Römer tuff has been used since Roman times, and was widely used again in Romanesque (and to a lesser extent

  6. Bulk and mechanical properties of the Paintbrush tuff recovered from borehole USW NRG-7/7A: Data report. Yucca Mountain Site Characterization Project

    International Nuclear Information System (INIS)

    Martin, R.J.; Boyd, P.J.; Noel, J.S.; Price, R.H.

    1995-05-01

    An integral part of the licensing procedure for the potential nuclear waste repository at Yucca Mountain, Nevada, involves prediction of the in situ rheology for the design and construction of the facility and the emplacement of canisters containing radioactive waste. The data used to model the thermal and mechanical behavior of the repository and surrounding lithologies include dry and saturated bulk densities, average grain density, porosity, compressional and shear wave velocities, elastic moduli, and compressional and tensional fracture strengths. In this study, a suite of experiments was performed on cores recovered from the USW NRG-717A borehole drilled in support of the Exploratory Studies Facility (ESF) at Yucca Mountain. USW NRG-7/7A was drilled to a depth of 1,513.4 feet through five thermal/mechanical units of Paintbrush tuff and terminating in the tuffaceous beds of the Calico IEUS. The thermal/mechanical stratigraphy was defined by Orfiz et al. to group rock horizons of similar properties for the purpose of simplifying modeling efforts. The relationship between the geologic stratigraphy and the thermal/mechanical stratigraphy is presented. The tuff samples in this study have a wide range of welding characteristics, and a smaller range of mineralogy and petrology characteristics. Generally, the samples are silicic, ash-fall tuffs that exhibit large variability in their elastic and strength properties

  7. Radionuclide Transport in Fractured Tuff under Episodic Flow Conditions

    Science.gov (United States)

    Hu, Q.; Sun, Y.; Ewing, R. P.

    2005-12-01

    The current conceptual model of radionuclide transport in unsaturated fractured rock includes water movement in fractures, with migration of the entrained radionuclides being retarded by diffusion into and sorption within the rock matrix. Water infiltration and radionuclide transport through low-permeability unsaturated fractured rock are episodic and intermittent in nature, at least at local scales. Under episodic flow conditions, the matrix is constantly imbibing or draining, and this fluctuating wetness both drives two-way advective movement of radionuclides, and forces changes in the matrix diffusivity. This work is intended to examine, both experimentally and numerically, how radionuclide transport under episodic flow conditions is affected by the interacting processes of imbibition and drainage, diffusion, and matrix sorption. Using Topopah Spring welded volcanic tuff, collected from the potential repository geologic unit at Yucca Mountain for storing high-level nuclear waste, we prepared a saw-cut fracture core (length 10.2 cm, diameter 4.4 cm, and fracture aperture 100 microns). The dry core was packed into a flow reactor, flushed with CO2, then saturated via slow pumping (0.01 mL/min) of synthetic groundwater. The fractured core was then flushed with air at 97% relative humidity (to simulate in situ unsaturated fractured rock conditions at Yucca Mountain), then the episodic transport experiment was conducted. Episodic flow involved 4 cycles of tracer solution flow within the fracture, followed by flushing with high humidity air. Each flow episode contained a different suite of non-sorbing and sorbing tracers, which included 3H, ReO4- (a chemical analog for 99TcO4-), I- (for 129I-), Sr and Cs (for 90Sr and 137Cs), plus the radionuclides 235U, 237Np, and 241Pu. These radionuclides span a variety of sorption strengths and represent a large fraction of the radionuclides of concern at the potential Yucca Mountain repository. Meanwhile, the non-sorbing 3H and Re

  8. Mechanical characterization of densely welded Apache Leap tuff

    International Nuclear Information System (INIS)

    Fuenkajorn, K.; Daemen, J.J.K.

    1991-06-01

    An empirical criterion is formulated to describe the compressive strength of the densely welded Apache Leap tuff. The criterion incorporates the effects of size, L/D ratio, loading rate and density variations. The criterion improves the correlation between the test results and the failure envelope. Uniaxial and triaxial compressive strengths, Brazilian tensile strength and elastic properties of the densely welded brown unit of the Apache Leap tuff have been determined using the ASTM standard test methods. All tuff samples are tested dry at room temperature (22 ± 2 degrees C), and have the core axis normal to the flow layers. The uniaxial compressive strength is 73.2 ± 16.5 MPa. The Brazilian tensile strength is 5.12 ± 1.2 MPa. The Young's modulus and Poisson's ratio are 22.6 ± 5.7 GPa and 0.20 ± 0.03. Smoothness and perpendicularity do not fully meet the ASTM requirements for all samples, due to the presence of voids and inclusions on the sample surfaces and the sample preparation methods. The investigations of loading rate, L/D radio and cyclic loading effects on the compressive strength and of the size effect on the tensile strength are not conclusive. The Coulomb strength criterion adequately represents the failure envelope of the tuff under confining pressures from 0 to 62 MPa. Cohesion and internal friction angle are 16 MPa and 43 degrees. The brown unit of the Apache Leap tuff is highly heterogeneous as suggested by large variations of the test results. The high intrinsic variability of the tuff is probably caused by the presence of flow layers and by nonuniform distributions of inclusions, voids and degree of welding. Similar variability of the properties has been found in publications on the Topopah Spring tuff at Yucca Mountain. 57 refs., 32 figs., 29 tabs

  9. Reference repository design concept for bedded salt

    International Nuclear Information System (INIS)

    Carpenter, D.W.; Martin, R.W.

    1980-01-01

    A reference design concept is presented for the subsurface portions of a nuclear waste repository in bedded salt. General geologic, geotechnical, hydrologic and geochemical data as well as descriptions of the physical systems are provided for use on generic analyses of the pre- and post-sealing performance of repositories in this geologic medium. The geology of bedded salt deposits and the regional and repository horizon stratigraphy are discussed. Structural features of salt beds including discontinuities and dissolution features are presented and their effect on repository performance is discussed. Seismic hazards and the potential effects of earthquakes on underground repositories are presented. The effect on structural stability and worker safety during construction from hydrocarbon and inorganic gases is described. Geohydrologic considerations including regional hydrology, repository scale hydrology and several hydrological failure modes are presented in detail as well as the hydrological considerations that effect repository design. Operational phase performance is discussed with respect to operations, ventilation system, shaft conveyances, waste handling and retrieval systems and receival rates of nuclear waste. Performance analysis of the post sealing period of a nuclear repository is discussed, and parameters to be used in such an analysis are presented along with regulatory constraints. Some judgements are made regarding hydrologic failure scenarios. Finally, the design and licensing process, consistent with the current licensing procedure is described in a format that can be easily understood

  10. Reference repository design concept for bedded salt

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, D.W.; Martin, R.W.

    1980-10-08

    A reference design concept is presented for the subsurface portions of a nuclear waste repository in bedded salt. General geologic, geotechnical, hydrologic and geochemical data as well as descriptions of the physical systems are provided for use on generic analyses of the pre- and post-sealing performance of repositories in this geologic medium. The geology of bedded salt deposits and the regional and repository horizon stratigraphy are discussed. Structural features of salt beds including discontinuities and dissolution features are presented and their effect on repository performance is discussed. Seismic hazards and the potential effects of earthquakes on underground repositories are presented. The effect on structural stability and worker safety during construction from hydrocarbon and inorganic gases is described. Geohydrologic considerations including regional hydrology, repository scale hydrology and several hydrological failure modes are presented in detail as well as the hydrological considerations that effect repository design. Operational phase performance is discussed with respect to operations, ventilation system, shaft conveyances, waste handling and retrieval systems and receival rates of nuclear waste. Performance analysis of the post sealing period of a nuclear repository is discussed, and parameters to be used in such an analysis are presented along with regulatory constraints. Some judgements are made regarding hydrologic failure scenarios. Finally, the design and licensing process, consistent with the current licensing procedure is described in a format that can be easily understood.

  11. Dehydration and rehydration of a tuff vitrophyre

    International Nuclear Information System (INIS)

    Vaniman, D.; Bish, D., Chipera, S.

    1993-01-01

    The basal vitrophyre of the Topopah Spring Member of the Paintbrush Tuff at Yucca Mountain, Nevada, is a perlitic glass with 2.8 to 4.6% water. The dehydration of this vitrophyre was studied by thermogravimetric analysis (TGA) and by isothermal heating at 50 degrees, 100 degrees, 200 degrees, and 400 degrees C for 3.4 years followed by 1.1 years of rehydration at high controlled humidity (∼79% relative humidity). No crystallization of the glass was observed in long-term dehydration or rehydration; the only observed chemical alteration was loss of up to 60% of original fluorine. TGA studies show a characteristic two-stage dehydration of the vitrophyre, with two-thirds to three-fourths weight loss occurring most rapidly at temperatures ranging from 278 degrees to 346 degrees C in 10 degrees C/min heating experiments. The remaining water, about 1% in all of the vitrophyre samples studied regardless of total water content, is lost only on second-stage heating to temperatures above 650 degrees C. Long-term isothermal heating at ≤400 degrees C releases only the first-stage water. Loss of essentially all first-stage water occurred in less than 1 hour at 400 degrees C; proportionately lower losses were obtained at 200 degrees and 100 degrees C. Small (0.2%) water loss occurred in the 50 degrees C experiment. A time-temperature-dehydration diagram generated from the isothermal heating data shows a clustering of dehydration contours that are the equilibrium equivalent of the rapid first-stage water loss in dynamic TGA experiments. These dry-heating experiments provide an end-member characterization of glass transformations for comparison with water-saturated heating experiments in which glass alteration is prominent. 29 figs., 7 figs., 7 tabs

  12. Preclosure analysis of conceptual waste package designs for a nuclear waste repository in tuff

    International Nuclear Information System (INIS)

    O'Neal, W.C.; Gregg, D.W.; Hockman, J.N.; Russell, E.W.; Stein, W.

    1984-01-01

    This report discusses the selection and analysis of conceptual waste package developed by the Nevada Nuclear Waste Storage Investigations (NNWSI) project for possible disposal of high-level nuclear waste at a candidate site at Yucca Mountain, Nevada. The design requirements that the waste package must conform to are listed, as are several desirable design considerations. Illustrations of the reference and alternative designs are shown. Four austenitic stainless steels (316L SS, 321 SS, 304L SS and Incoloy 825 high nickel alloy) have been selected for candidate canister/overpack materials, and 1020 carbon steel has been selected as the reference metal for the borehole liners. A summary of the results of technical and ecnonmic analyses supporting the selection of the conceptual waste package designs is included. Postclosure containment and release rates are not analyzed in this report

  13. Corrosion test plan to guide canister material selection and design for a tuff repository

    International Nuclear Information System (INIS)

    McCright, R.D.; van Konynenburg, R.A.; Ballou, L.B.

    1983-11-01

    Corrosion rates and the mode of corrosion attack form a most important basis for selection of canister materials and design of a nuclear waste package. Type 304L stainless steel was selected as the reference material for canister fabrication because of its generally excellent corrosion resistance in water, steam and air. However, 304L may be susceptible to localized and stress-assisted forms of corrosion under certain conditions. Alternative alloys are also investigated; these alloys were chosen because of their improved resistance to these forms of corrosion. The fabrication and welding processes, as well as the glass pouring operation for defense and commercial high-level wastes, may influence the susceptibility of the canister to localized and stress forms of corrosion. 12 references, 2 figures, 4 tables

  14. Absolute Paleointensity Study of Miocene Tiva Canyon Tuff, Yucca Mountain, Nevada

    Science.gov (United States)

    Patiman, A.; Bowles, J.

    2014-12-01

    geomagnetic paleointensity for the Miocene. Post-emplacement vapor-phase alteration might be expected to alter magnetic mineralogy and magnetization, and has been reported in the upper portions of the TC tuff, but not in the lower sections discussed here.

  15. Magnesium oxide-impregnated tuff soil-derived ceramic: a novel cadmium(II) adsorbing media

    Science.gov (United States)

    Salim, Md; Bhakta, Jatindra N.; Maneesh, Namburath; Munekage, Yukihiro; Motomura, Kevin

    2017-07-01

    The contamination of cadmium (Cd) in the aquatic environment is one of the serious environmental and human health's risks. The present study attempted to develop the potential magnesium oxide (MgO)-impregnated tuff soil-derived ceramic (MITDC)-based novel adsorbent media for adsorbing higher rate of cadmium [Cd(II)] from water phase. A potential MITDC adsorbent media was developed using volcanic raw tuff soil and its Cd(II) adsorption capacity from water phase was evaluated comparing with the raw tuff soil. A series of studies were carried out in an agitated batch method at 20 ± 2 °C to characterize the adsorption capacity of MITDC under different conditions of factors, such as contact time (0-360 min), initial pH (3-11) of solution, dose of MITDC (2, 5, 7.5 and 10 g/L), and initial concentration of Cd(II) (5, 10, 20, 30, and 40 mg/L), influencing the adsorption mechanism. MITDC exhibited the equilibrium state of maximum Cd(II) adsorption at the contact time 120 min and pH 4.7 (removed 98.2 % Cd) when initial Cd(II) concentration was 10 mg/L in the present study. The dose of 7.5 g MITDC/L showed maximum removal of Cd(II) from water. Experimental data were described by the Freundlich and the Langmuir isotherms and equilibrium data fitted well with the Langmuir model ( R 2 = 0.996). The Cd(II) adsorption capacity of MITDC was 31.25 mg/g. The high Cd(II) adsorption capacity indicated that novel MITDC could be used as a potential ceramic adsorbent media to remove high rate of Cd(II) from aqueous phase.

  16. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    D. Rigby

    2004-11-10

    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).

  18. 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)

  19. Uranium, thorium and trace elements in geologic occurrences as analogues of nuclear waste repository conditions

    International Nuclear Information System (INIS)

    Wollenberg, H.A.; Brookins, D.G.; Cohen, L.H.; Flexser, S.; Abashian, M.; Murphy, M.; Williams, A.E.

    1984-01-01

    Contact zones between intrusive rocks and tuff, basalt, salt and granitic rock were investigated as possible analogues of nuclear waste repository conditions. Results of detailed studies of contacts between quartz monzonite of Laramide age, intrusive into Precambrian gneiss, and a Tertiary monzonite-tuff contact zone indicate that uranium, thorium and other trace elements have not migrated significantly from the more radioactive instrusives into the country rock. Similar observations resulted from preliminary investigations of a rhyodacite dike cutting basalt of the Columbia River plateau and a kimberlitic dike cutting bedded salt of the Salina basin. This lack of radionuclide migration occurred in hydrologic and thermal conditions comparable to, or more severe than those expected in nuclear waste repository environments and over time periods of the order of concern for waste repositories. Attention is now directed to investigation of active hydrothermal systems in candidate repository rock types, and in this regard a preliminary set of samples has been obtained from a core hole intersecting basalt underlying the Newberry caldera, Oregon, where temperatures presently range from 100 to 265 0 C. Results of mineralogical and geochemical investigations of this core should indicate the alteration mineralogy and behavior of radioelements in conditions analogous to those in the near field of a repository in basalt

  20. Repository Rodeo Redux

    CERN Document Server

    Anez, Melissa; Donohue, Tim; Fyson, Will; Simko, Tibor; Wilcox, David

    2017-01-01

    You’ve got more repository questions and we’ve got more answers! Last year’s Repository Rodeo panel was a huge success, so we’re taking the show on the road to Brisbane for OR2017. Join representatives from the DSpace, Eprints, Fedora, Hydra, and Islandora communities as we (briefly) explain what each of our repositories actually does. We'll also talk about the directions of our respective technical and community developments, and related to the conference theme of Open: Innovation Knowledge Repositories, offer brief observations about the latest, most promising and/or most surprising innovations in our space. This panel will be a great opportunity for newcomers to Open Repositories to get a crash course on the major repository options and meet representatives from each of their communities. After a brief presentation from each representative, we'll open the session up for questions from the audience.

  1. Mineralogy and petrology of tuff units from a UE25a-1 drill site, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Sykes, M.L.; Heiken, G.H.; Smyth, J.R.

    1979-11-01

    Drill hole UE25a-1 has penetrated tuffs of Tertiary age which contain two major zeolitized horizons at depths below 380 m. These horizons are restricted to low-density, high-porosity nonwelded tuffs below the basal vitrophyre of the Topopah Springs Member of the Paintbrush Tuff (approximately 70 m above the current water table), and interfinger with more-densely-welded devitrified tuffs of granophyric mineralogy. Zeolites occur as glass pyroclast replacement, vug linings, and fracture fillings. Nonwelded units above the welded portion of the Topopah Springs Member are essentially unaltered, indicating that they have never been ground water-saturated for any significant length of time. Zeolite mineral assemblages appear to be characteristic of low temperature ( 0 C) ground water alteration of glass in an open hydrologic system. The principal zeolite phase is high-Si clinoptilolite with Si/Al ratios of 4.7 to 6.0. Ca tends to be the dominant large-radius cation, but grains with dominant K or Na are not uncommon, particularly with increasing depth. Compositional variations in clinoptilolite may be due to ground water composition or original pyroclast composition. Minor amounts of mordenite, characterized by lower silica content ( 10 wt % Na 2 O + K 2 O), occur as vug fillings at depths below 500 m. Presence of mordenite may indicate slightly elevated alteration temperatures, but more likely reflects enrichment of ground water in alkalis with depth. Mineralogical, compositional, and textural similarities of the zeolitized tuffs from UE25a-1 and J-13 are compatible with a single episode of crystallization. 16 figures

  2. A first survey of disruption scenarios for a high-level-waste repository at Yucca Mountain, Nevada: Nevada Nuclear Waste Storage Investigations Project

    International Nuclear Information System (INIS)

    Ross, B.

    1987-12-01

    A high-level-waste repository located in unsaturated welded tuff at Yucca Mountain, Nevada, would rely on six different, although not entirely independent, barriers to prevent escape of radioactivity. These barriers are the waste canister, fuel cladding, dissolution of the spent fuel itself, and movement of released contaminants in the unsaturated Topopah Spring welded tuff unit, the unsaturated Calico Hills nonwelded tuff unit, and the saturated tuff aquifer. Fifty-eight processes and events that might affect such a repository were examined. Eighty-four different sequences were identified by which these processes and events could lead to failure of one or more barriers. Sequences that had similar consequences were grouped into 17 categories: direct release, repository flooding, colloid formation, increased water flux through the repository, accelerated fracture flow, water diverted toward the waste package, accelerated dissolution mechanisms, accelerated cladding corrosion mechanisms, accelerated canister corrosion mechanisms, canister breakage, fracture flow in the Topopah Spring welded unit without increased moisture flux, reduced sorption in the Topopah Spring welded unit, water table rise above the Calico Hills nonwelded unit, fracture flow in the Calico Hills nonwelded unit, new discharge points, and faster flow in the saturated zone. 52 refs., 6 figs., 1 tab

  3. Administrative Data Repository (ADR)

    Data.gov (United States)

    Department of Veterans Affairs — The Administrative Data Repository (ADR) was established to provide support for the administrative data elements relative to multiple categories of a person entity...

  4. Records Control Schedules Repository

    Data.gov (United States)

    National Archives and Records Administration — The Records Control Schedules (RCS) repository provides access to scanned versions of records schedules, or Standard Form 115, Request for Records Disposition...

  5. CAED Document Repository

    Data.gov (United States)

    U.S. Environmental Protection Agency — Compliance Assurance and Enforcement Division Document Repository (CAEDDOCRESP) provides internal and external access of Inspection Records, Enforcement Actions, and...

  6. Performance assessment of the direct disposal in unsaturated tuff or spent nuclear fuel and high-level waste owned by USDOE: Volume 2, Methodology and results

    Energy Technology Data Exchange (ETDEWEB)

    Rechard, R.P. [ed.

    1995-03-01

    This assessment studied the performance of high-level radioactive waste and spent nuclear fuel in a hypothetical repository in unsaturated tuff. The results of this 10-month study are intended to help guide the Office of Environment Management of the US Department of Energy (DOE) on how to prepare its wastes for eventual permanent disposal. The waste forms comprised spent fuel and high-level waste currently stored at the Idaho National Engineering Laboratory (INEL) and the Hanford reservations. About 700 metric tons heavy metal (MTHM) of the waste under study is stored at INEL, including graphite spent nuclear fuel, highly enriched uranium spent fuel, low enriched uranium spent fuel, and calcined high-level waste. About 2100 MTHM of weapons production fuel, currently stored on the Hanford reservation, was also included. The behavior of the waste was analyzed by waste form and also as a group of waste forms in the hypothetical tuff repository. When the waste forms were studied together, the repository was assumed also to contain about 9200 MTHM high-level waste in borosilicate glass from three DOE sites. The addition of the borosilicate glass, which has already been proposed as a final waste form, brought the total to about 12,000 MTHM.

  7. Performance assessment of the direct disposal in unsaturated tuff or spent nuclear fuel and high-level waste owned by USDOE: Volume 2, Methodology and results

    International Nuclear Information System (INIS)

    Rechard, R.P.

    1995-03-01

    This assessment studied the performance of high-level radioactive waste and spent nuclear fuel in a hypothetical repository in unsaturated tuff. The results of this 10-month study are intended to help guide the Office of Environment Management of the US Department of Energy (DOE) on how to prepare its wastes for eventual permanent disposal. The waste forms comprised spent fuel and high-level waste currently stored at the Idaho National Engineering Laboratory (INEL) and the Hanford reservations. About 700 metric tons heavy metal (MTHM) of the waste under study is stored at INEL, including graphite spent nuclear fuel, highly enriched uranium spent fuel, low enriched uranium spent fuel, and calcined high-level waste. About 2100 MTHM of weapons production fuel, currently stored on the Hanford reservation, was also included. The behavior of the waste was analyzed by waste form and also as a group of waste forms in the hypothetical tuff repository. When the waste forms were studied together, the repository was assumed also to contain about 9200 MTHM high-level waste in borosilicate glass from three DOE sites. The addition of the borosilicate glass, which has already been proposed as a final waste form, brought the total to about 12,000 MTHM

  8. THERMAL CONDUCTIVITY OF THE POTENTIAL REPOSITORY HORIZON

    Energy Technology Data Exchange (ETDEWEB)

    J.E. BEAN

    2004-09-27

    The primary purpose of this report is to assess the spatial variability and uncertainty of bulk thermal conductivity in the host horizon for the repository at Yucca Mountain. More specifically, the lithostratigraphic units studied are located within the Topopah Spring Tuff (Tpt) and consist of the upper lithophysal zone (Tptpul), the middle nonlithophysal zone (Tptpmn), the lower lithophysal zone (Tptpll), and the lower nonlithophysal zone (Tptpln). Design plans indicate that approximately 81 percent of the repository will be excavated in the Tptpll, approximately 12 percent in the Tptpmn, and the remainder in the Tptul and Tptpln (BSC 2004 [DIRS 168370]). This report provides three-dimensional geostatistical estimates of the bulk thermal conductivity for the four stratigraphic layers of the repository horizon. The three-dimensional geostatistical estimates of matrix and lithophysal porosity, dry bulk density, and matrix thermal conductivity are also provided. This report provides input to various models and calculations that simulate heat transport through the rock mass. These models include the ''Drift Degradation Analysis, Multiscale Thermohydrologic Model, Ventilation Model and Analysis Report, Igneous Intrusion Impacts on Waste Packages and Waste Forms, Drift-Scale Coupled Processes (DST and TH Seepage) Models'', and ''Drift Scale THM Model''. These models directly or indirectly provide input to the total system performance assessment (TSPA). The main distinguishing characteristic among the lithophysal and nonlithophysal units is the percentage of large-scale (centimeters-meters) voids within the rock. The Tptpul and Tptpll, as their names suggest, have a higher percentage of lithophysae than the Tptpmn and the Tptpln. Understanding the influence of the lithophysae is of great importance to understanding bulk thermal conductivity.

  9. Construction of the North Head (Maungauika) tuff cone: a product of Surtseyan volcanism, rare in the Auckland Volcanic Field, New Zealand

    Science.gov (United States)

    Agustín-Flores, Javier; Németh, Károly; Cronin, Shane J.; Lindsay, Jan M.; Kereszturi, Gábor

    2015-02-01

    The Auckland Volcanic Field (AVF) comprises at least 52 monogenetic eruption centres dispersed over ˜360 km2. Eruptions have occurred sporadically since 250 ka, predominantly when glacio-eustatic sea levels were lower than today. Now that around 35 % of the field is covered by shallow water (up to 30 m depth), any eruption occurring in the present or near future within this area may display Surtseyan dynamics. The North Head tuff cone evidences eruptive dynamics caused by magma interaction with seawater. The first stages of the eruption comprise a phreatomagmatic phase that built a 48-m-high tuff cone. North Head tuff deposits contain few lithic fragments (Auckland area was at least 10-12 m above the pre-eruptive surface. The hazards associated with this type of eruption pose a risk to the densely populated coastal residential zones and the activities of one of the busiest harbours in New Zealand.

  10. Investigation on repository layouts

    Energy Technology Data Exchange (ETDEWEB)

    Tanai, Kenji [Tokai, Works, Japan Nuclear Cycle Development Inst., Tokai, Ibaraki (Japan); Iwasa, Kengo; Hasegawa, Hiroshi [Head Office, Japan Nuclear Cycle Development Inst., Tokai, Ibaraki (Japan); Gouke, Mitsuo; Horita, Masakuni [Shimizu Corp., Tokyo (Japan); Noda, Masaru [Ohbayashi Corp., Tokyo (Japan)

    1999-11-01

    This report consists of three items : (1) Study of the repository configuration, (2) Study of the surface facilities configuration for construction, operation and backfilling, (3) Planning schedule. In the repository configuration, the basic factors influencing the design of the repository configuration are presented, and the results of studies of various possible repository configurations are presented for both hard and soft rock systems. Here, the minimum conditions regarding geological environment required to guide design are assumed, because it is difficult to determine the repository configuration without considering specific conditions of a disposal site. In the surface facility configuration, it is illustrated based on the results of construction, operation, backfilling studies for underground disposal facility and EIS report of CANADA. In the schedule, the overall schedule corresponding to the repository layout is outlined in link with the milestone of disposal schedule set forth in the government's basic policy. The assumptions and the basic conditions are summarized to examine the General Schedule from start of construction to closure of a repository. This summary is based on the technologies to be used for construction, operation and closure of a repository. The basic national policies form the framework for this review of the general schedule. (author)

  11. Nuclear waste repository siting

    International Nuclear Information System (INIS)

    Soloman, B.D.; Cameron, D.M.

    1987-01-01

    This paper discusses the geopolitics of nuclear waste disposal in the USA. Constitutional choice and social equity perspectives are used to argue for a more open and just repository siting program. The authors assert that every potential repository site inevitably contains geologic, environmental or other imperfections and that the political process is the correct one for determining sites selected

  12. Radioactive waste repository study

    International Nuclear Information System (INIS)

    1978-11-01

    This is the second part of a report of a preliminary study for AECL. It considers the requirements for an underground waste repository for the disposal of wastes produced by the Canadian Nuclear Fuel Program. The following topics are discussed with reference to the repository: 1) geotechnical assessment, 2) hydrogeology and waste containment, 3) thermal loading and 4) rock mechanics. (author)

  13. Monitored Geologic Repository Test Evaluation Plan

    Energy Technology Data Exchange (ETDEWEB)

    M.B. Skorska

    2002-01-02

    The Monitored Geologic Repository test & evaluation program will specify tests, demonstrations, examinations, and analyses, and describe procedures to conduct and document testing necessary to verify meeting Monitored Geologic Repository requirements for a safe and effective geologic repository for radioactive waste. This test program will provide assurance that the repository is performing as designed, and that the barriers perform as expected; it will also develop supporting documentation to support the licensing process and to demonstrate compliance with codes, standards, and regulations. This comprehensive program addresses all aspects of verification from the development of test requirements to the performance of tests and reporting of the test results. The ''Monitored Geologic Repository Test & Evaluation Plan'' provides a detailed description of the test program approach necessary to achieve the above test program objectives. This test plan incorporates a set of test phases focused on ensuring repository safety and operational readiness and implements a project-wide integrated product management team approach to facilitate test program planning, analysis, and implementation. The following sections provide a description of the individual test phases, the methodology for test program planning and analyses, and the management approach for implementing these activities.

  14. Transportation plan repository and archive.

    Science.gov (United States)

    2011-04-01

    This project created a repository and archive for transportation planning documents in Texas within the : established Texas A&M Repository (http://digital.library.tamu.edu). This transportation planning archive : and repository provides ready access ...

  15. In defense of Magnetite-Ilmenite Thermometry in the Bishop Tuff and its implication for gradients in silicic magma reservoirs

    Science.gov (United States)

    Evans, Bernard W; Hildreth, Edward; Bachmann, Olivier; Scaillet, Bruno

    2016-01-01

    Despite claims to the contrary, the compositions of magnetite and ilmenite in the Bishop Tuff correctly record the changing conditions of T and fO2 in the magma reservoir. In relatively reduced (∆NNO magmas (e.g., Bishop Tuff, Taupo units), Ti behaves compatibly (DTi ≈ 2-3.5), leading to a decrease in TiO2 activity in the melt with cooling and fractionation. In contrast, FeTi-oxides are poorer in TiO2 in more oxidized magmas (∆NNO > 1, e.g., Fish Canyon Tuff, Pinatubo), and the d(aTiO2)/dT slope can be negative. Biotite, FeTi-oxides, liquid, and possibly plagioclase largely maintained equilibrium in the Bishop Tuff magma (unlike the pyroxenes, and cores of quartz, sanidine, and zircon) prior ro and during a mixing event triggered by a deeper recharge, which, based on elemental diffusion profiles in minerals, took place at least several decades before eruption. Equilibrating phases and pumice compositions show evolving chemical variations that correlate well with mutually consistent temperatures based on the FeTi-oxides, sanidine-plagioclase, and ∆18O quartz-magnetite pairs. Early Bishop Tuff (EBT) temperatures are lower (700 to ~780‎°C) than temperatures (780 to >820°C) registered in Late Bishop Tuff (LBT), the latter defined here not strictly stratigraphically, but by the presence of orthopyroxene and reverse-zoned rims on quartz and sanidine. The claimed similarity in compositions, Zr-saturation temperatures and thermodynamically calculated temperatures (730-740°C) between EBT and less evolved LBT reflect the use of glass inclusions in quartz cores in LBT that were inherited from the low temperature rhyolitic part of the reservoir characteristic of the EBT. LBT temperatures as high as 820°C, the preservation of orthopyroxene, and the presence of reverse-zoned minerals (quartz, sanidine, zircons) are consistent with magma recharge at the base of the zoned reservoir, heating the cooler rhyolitic melt, partly remelting cumulate mush, and introducing

  16. Method development and strategy for the characterization of complexly faulted and fractured rhyolitic tuffs, Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Karasaki, K. [Lawrence Berkeley Lab., CA (United States); Galloway, D. [Geological Survey, Sacramento, CA (United States)

    1991-06-01

    The planned high-level nuclear waste repository at Yucca Mountain, Nevada, would exist in unsaturated, fractured welded tuff. One possible contaminant pathway to the accessible environment is transport by groundwater infiltrating to the water table and flowing through the saturated zone. Therefore, an effort to characterize the hydrology of the saturated zone is being undertaken in parallel with that of the unsaturated zone. As a part of the saturated zone investigation, there wells-UE-25c{number_sign}1, UE-25c{number_sign}2, and UE-25c{number_sign}3 (hereafter called the c-holes)-were drilled to study hydraulic and transport properties of rock formations underlying the planned waste repository. The location of the c-holes is such that the formations penetrated in the unsaturated zone occur at similar depths and with similar thicknesses as at the planned repository site. In characterizing a highly heterogeneous flow system, several issues emerge. (1) The characterization strategy should allow for the virtual impossibility to enumerate and characterize all heterogeneities. (2) The methodology to characterize the heterogeneous flow system at the scale of the well tests needs to be established. (3) Tools need to be developed for scaling up the information obtained at the well-test scale to the larger scale of the site. In the present paper, the characterization strategy and the methods under development are discussed with the focus on the design and analysis of the field experiments at the c-holes.

  17. Petrochemical variation of Topopah Spring tuff matrix with depth (stratigraphic level), drill hole USW G-4, Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Byers, F.M. Jr.

    1985-12-01

    This study describes and interprets petrochemical variation of the matrix (excluding fractures and large gas cavities) of the Topopah Spring Member of the Paintbrush Tuff. This tuff includes the candidate host rock for a high-level nuclear waste repository at Yucca Mountain on the Nevada Test Site. Cored hole USW G-4, near the site of a potential exploratory shaft at Yucca Mountain, penetrated 359.4 m (1179 ft) of the member within the unsaturated zone. This study shows that petrographic textures and chemistry of the matrix vary systematically within recognizable lithologic subunits related to crystallization (cooling) zones, welding (compaction) zones, and compositional zones (rhyolite versus quartz latite). The methods used for this study include petrographic modal thin section analysis using an automated counter and electron microprobe analysis of the groundmass. Distinctive textural categories are defined, and they can be ranked from finest to coarsest as vitrophyre (glass), cryptocrystalline groundmass, spherulites, granophyre, lithic fragments, and phenocrysts. The two main groundmass compositions are also defined: rhyolite high silica) and quartz latite. The value of these petrochemical studies lies in providing microscopic criteria for recognizing the zonal subunits where they may have greatly limited exposure, as in mined drifts and in core from horizontal drill holes. For example, the lower nonlithophysal zone can be distinguished microscopically from the middle nonlithophysal zone by (1) degree of compaction, (2) amount of quartz, and (3) amount of lithic fragments. The variability between these textural categories should also be considered in designing physical and chemical tests of the Topopah Spring.

  18. The behaviour of consolidated volcanic tuffs: weathering mechanisms under simulated laboratory conditions

    Science.gov (United States)

    Stück, H.; Forgó, L. Z.; Rüdrich, J.; Siegesmund, S.; Török, Á.

    2008-12-01

    Five volcanic tuffs ranging from dacitic tuffs of Hungary to rhyolite, phonolite and basaltic tuffs of Germany were consolidated under laboratory conditions. Prior to consolidation an anti-hygro, a hydrous consolidant, which reduces the swelling ability of clay minerals, was applied. The three consolidants, a silicic acid ester (SAE), an elastic silicic acid ester (eSAE) and an acrylate resin (PMMA) were applied on test specimens under vacuum. Petrographic characterisation (polarizing microscopy, XRD, SEM) provided data for fabric analyses and the mineral composition of the tuffs. Changes in fabric, effective porosity, density, tensile strength, ultrasonic wave velocity were evaluated after the treatment. Weathering simulation tests such as hygric dilatation and thermal dilatation aimed to prove the effectiveness of consolidation and the durability of consolidated tuff samples. More than 500 samples were analysed. The tests showed that SAE caused the highest increase in indirect tensile strength. The water absorption and the pore size distribution of the tuffs were modified by consolidation. The PMMA reduced the water absorption the most, whereas SAE modified it the least. All the tested consolidants increased the thermal dilatation of the tuffs. The changes in hygric dilatation were not uniform: for most tuffs SAE increased and PMMA decreased the hygric dilatation, although the clay-rich Habichtswald tuff showed the opposite trend. The changes in hygric and thermal behaviour of consolidated tuff require special care when specific consolidants are chosen. These products modify the physical properties of consolidated tuffs and change the behaviour of weathering.

  19. Effects of mineralogy on the sorption of strontium and cesium onto Calico Hills tuff

    International Nuclear Information System (INIS)

    Meyer, R.E.; Arnold, W.D.; Case, F.I.; O'Kelley, G.D.; Land, J.F.

    1990-01-01

    Sorption and desorption measurements were made of strontium and cesium onto clinoptilolite and Calico Hills Tuff. The object was to see whether there was a correlation between sorption of strontium and cesium onto Calico Hills Tuff and the clinoptilolite based on the content of clinoptilolite in the Calico Hills Tuff. If sorption onto Calico Hills Tuff is solely due to the presence of clinoptilolite, then the ratios of the sorption ratios on tuff to those on clinoptilolite at similar conditions should be the weight fraction of the clinoptilolite in the tuff. The experimental evidence showed that the ratios were generally near 0.5 for both cesium and strontium sorption and that ion-exchange processes were operative for the clinoptilolite and the tuff. However, the ratios differed to a small extent for different conditions, and there were indications that other sorption processes were also involved. 7 refs., 7 figs., 2 tabs

  20. Miocene Slănic Tuff, Eastern Carpathians, Romania, in the Context of Badenian Salinity Crisis

    Directory of Open Access Journals (Sweden)

    Ana-Voica Bojar

    2018-02-01

    Full Text Available New geochronological investigations for the Slănic Formation, correlated with previous bio- and lithostratigaphical information, allow for a better succession of events for the Middle Miocene, including the absolute age of the Badenian salinity crisis in the bend sector of the Eastern Carpathians. Within the green Slănic Tuff, white tuff layers were in evidence. The main element distribution of the white and green tuffs indicates a dacitic composition, with higher SiO2 content for the white tuff. The white tuff has a distinct mineralogical composition with quartz, plagioclase, biotite and clinoptilolite. From such a tuff layer a biotite concentrate gives a 40Ar/39Ar age of 13.7 ± 0.2 Ma. As above these tuff layers discrete levels of gypsum occur, the age documents the beginning of the restrictive circulation and formation of evaporites in this sector of Carpathians during Badenian times.

  1. Gas generation in repositories

    International Nuclear Information System (INIS)

    Biddle, P.; Rees, J.H.; McGahan, D.; Rushbrook, P.E.

    1987-09-01

    The nature and quantities of gases likely to be produced by various processes in repositories for low level and intermediate level radioactive wastes are examined in this preliminary study. Many simplifying assumptions are made where published or experimental data is unavailable. The corrosion of the canisters and metallic components in wastes is likely to be the major gas production process in both types of repository. A significant contribution from microbiological activity is expected to occur in low level repositories, predominantly where no cement grouting of the cans has been carried out. A number of areas for further research, required before a more comprehensive study could be carried out, have been identified. (author)

  2. Centralized mouse repositories.

    Science.gov (United States)

    Donahue, Leah Rae; Hrabe de Angelis, Martin; Hagn, Michael; Franklin, Craig; Lloyd, K C Kent; Magnuson, Terry; McKerlie, Colin; Nakagata, Naomi; Obata, Yuichi; Read, Stuart; Wurst, Wolfgang; Hörlein, Andreas; Davisson, Muriel T

    2012-10-01

    Because the mouse is used so widely for biomedical research and the number of mouse models being generated is increasing rapidly, centralized repositories are essential if the valuable mouse strains and models that have been developed are to be securely preserved and fully exploited. Ensuring the ongoing availability of these mouse strains preserves the investment made in creating and characterizing them and creates a global resource of enormous value. The establishment of centralized mouse repositories around the world for distributing and archiving these resources has provided critical access to and preservation of these strains. This article describes the common and specialized activities provided by major mouse repositories around the world.

  3. Preliminary design of the repository. Stage 2

    International Nuclear Information System (INIS)

    Saanio, T.; Kirkkomaeki, T.; Keto, P.; Kukkola, T.; Raiko, H.

    2007-04-01

    Spent nuclear fuel from Finnish nuclear power plants will be disposed of in deep bedrock in Olkiluoto, Eurajoki. The repository is planned to be excavated at a depth of 400 - 500 metres. Access routes to the repository include a 1:10 inclined access tunnel, and vertical shafts. The fuel is encapsulated in the encapsulation plant above ground and transferred to the repository in the canister lift. Deposition tunnels, central tunnels and technical rooms are excavated at the disposal level. The canisters are deposited in deposition holes that are covered with bentonite blocks. The deposition holes are bored in the floors of the deposition tunnels. The central tunnel system consists of two parallel central tunnels that are inter-connected at certain distances. Two parallel central tunnels improve the fire safety of the rooms and also allow flexible backfilling and closing of the deposition tunnels in stages at the operational phase of the repository. An underground rock characterization facility, ONKALO, is excavated at the disposal level to support and confirm investigations carried out from above ground. ONKALO is designed so that it can later serve as part of the repository. ONKALO excavations were started in 2004. The repository will be excavated in the 2010s and operation will start in 2020. The fifth nuclear power unit makes the operational phase of the repository very long. Parts of the repository will be excavated and closed over the long operational period. The repository can be constructed at one or several levels. The one-storey alternative is the so-called reference alternative in this preliminary design report. The two-storey alternative is also taken into account in the ONKALO designs. The preliminary designs of the repository are presented as located in Olkiluoto. The location of the repository will be revised when more information on the bedrock has been gained. More detailed data of the circumstances will be obtained from above ground investigations

  4. Review of the thermal stability and cation exchange properties of the zeolite minerals clinoptilolite, mordenite, and analcime; applications to radioactive waste isolation in silicic tuff

    International Nuclear Information System (INIS)

    Smyth, J.R.; Caporuscio, F.A.

    1981-06-01

    Silicic tuffs of the southern Great Basin and basalts of the Columbia River Plateau are under investigation as potential host rocks for high- and intermediate-level radioactive wastes. Nonwelded and partially welded tuffs may contain major amounts (> 50%) of the zeolite minerals clinoptilolite, mordenite, and analcime. Densely welded tuffs and some basalt flows may contain clinoptilolite as fracture filling that limits the permeability of these rocks. The cation exchange properties of these zeolite minerals allow them to pose a formidable natural barrier to the migration of cationic species of various radionuclides in aqueous solutions. However, these minerals are unstable at elevated temperatures and at low water-vapor pressures and may break down either by reversible dehydration or by irreversible mineralogical reactions. All the breakdown reactions occurring at increased temperature involve a net volume reduction and evolution of fluids. Thus, they may provide a pathway (shrinkage fractures) and a driving force (fluid pressure) for release of radionuclides to the biosphere. These reactions may be avoided by keeping zeolite-bearing horizons saturated with water and below about 85 0 C. This may restrict allowable gross thermal loadings in waste repositories in volcanic rocks

  5. Physical and hydrologic properties of outcrop samples from a nonwelded to welded tuff transition, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Rautman, C.A.; Flint, L.E.; Flint, A.L.; Istok, J.D.

    1995-01-01

    Quantitative material-property data are needed to describe lateral and vertical spatial variability of physical and hydrologic properties and to model ground-water flow and radionuclide transport at the potential Yucca Mountain nuclear-waste repository site in Nevada. As part of on-going site characterization studies of Yucca Mountain directed toward this understanding of spatial variability, laboratory measurements of porosity, bulk and particle density, saturated hydraulic conductivity, and sorptivity have been obtained for a set of outcrop samples that form a systematic, two-dimensional grid that covers a large exposure of the basal Tiva Canyon Tuff of the Paintbrush Group of Miocene age at Yucca Mountain. The samples form a detailed vertical grid roughly parallel to the transport direction of the parent ash flows, and they exhibit material-property variations in an interval of major lithologic change overlying a potential nuclear-waste repository at Yucca Mountain. The observed changes in hydrologic properties were systematic and consistent with the changes expected for the nonwelded to welded transition at the base of a major ash-flow sequence. Porosity, saturated hydraulic conductivity, and sorptivity decreased upward from the base of the Tiva Canyon Tuff, indicating the progressive compaction of ash-rich volcanic debris and the onset of welding with increased overburden pressure from the accumulating ash-flow sheet. The rate of decrease in the values of these material properties varied with vertical position within the transition interval. In contrast, bulk-density values increased upward, a change that also is consistent with progressive compaction and the onset of welding. Particle-density values remained almost constant throughout the transition interval, probably indicating compositional (chemical) homogeneity

  6. MONITORED GEOLOGIC REPOSITORY SYSTEMS REQUIREMENTS DOCUMENT

    International Nuclear Information System (INIS)

    V. Trebules

    2006-01-01

    This document establishes the Monitored Geologic Repository system requirements for the U.S. Department of Energy's (DOE's) Civilian Radioactive Waste Management System (CRWMS). These requirements are based on the ''Civilian Radioactive Waste Management System Requirements Document'' (CRD) (DOE 2004a). The ''Monitored Geologic Repository Systems Requirements Document'' (MGR-RD) is developed in accordance with LP-3.3 SQ-OCRWM, ''Preparation, Review, and Approval of Office of Repository Development Requirements Document''. As illustrated in Figure 1, the MGR-RD forms part of the DOE Office of Civilian Radioactive Waste Management Technical Requirements Baseline. Revision 0 of this document identifies requirements for the current phase of repository design that is focused on developing a preliminary design for the repository and will be included in the license application submitted to the U.S. Nuclear Regulatory Commission for a repository at Yucca Mountain in support of receiving a construction authorization and subsequent operating license. As additional information becomes available, more detailed requirements will be identified in subsequent revisions to this document

  7. MONITORED GEOLOGIC REPOSITORY SYSTEMS REQUIREMENTS DOCUMENT

    Energy Technology Data Exchange (ETDEWEB)

    V. Trebules

    2006-06-02

    This document establishes the Monitored Geologic Repository system requirements for the U.S. Department of Energy's (DOE's) Civilian Radioactive Waste Management System (CRWMS). These requirements are based on the ''Civilian Radioactive Waste Management System Requirements Document'' (CRD) (DOE 2004a). The ''Monitored Geologic Repository Systems Requirements Document'' (MGR-RD) is developed in accordance with LP-3.3 SQ-OCRWM, ''Preparation, Review, and Approval of Office of Repository Development Requirements Document''. As illustrated in Figure 1, the MGR-RD forms part of the DOE Office of Civilian Radioactive Waste Management Technical Requirements Baseline. Revision 0 of this document identifies requirements for the current phase of repository design that is focused on developing a preliminary design for the repository and will be included in the license application submitted to the U.S. Nuclear Regulatory Commission for a repository at Yucca Mountain in support of receiving a construction authorization and subsequent operating license. As additional information becomes available, more detailed requirements will be identified in subsequent revisions to this document.

  8. Memory provisions for the Manche Surface Repository

    International Nuclear Information System (INIS)

    Dumont, Jean-Noel; Espiet-Subert, Florence

    2015-01-01

    The French La Manche repository site received its last radioactive waste package in 1994. In 2003, the official surveillance phase of the closed repository started under the supervision of Andra (the national industrial operator), the French Nuclear Safety Authority (ASN) and society (e.g. the local municipalities). Florence Espiet explained that information on the existence of the repository, its content, how it was operated and how it works needs to be preserved. It also is planned to review the information periodically for a minimum of 300 years. She described the creation of two documents on memory (a detailed and a summary one), both on permanent paper, and the preservation of the land registration. The latter constitutes 'passive' provisions for preserving memory. In addition, a number of 'active' provisions are and will be put in place: guided visits, exhibitions, partnerships with organisations dealing with memory preservation, and the creation of a think tank. The latter consists of local citizens and politicians, retired employees from Andra and artists that meet several times a year and reflect on memory preservation from the perspective of, for instance, local history, education, arts and rituals. Finally, two types of markers will be used to preserve the repository's memory: i) three herbaria cataloguing the plants growing on the site of the repository, including a very short description of the repository, will be stored at different sites in France; ii) a stele indicating the main characteristics of the repository, potentially linked to an art work, will be erected at the repository

  9. National Radwaste Repository Mochovce

    International Nuclear Information System (INIS)

    2000-01-01

    In this leaflet the National Radioactive Waste Repository in Mochovce (Repository) is described. The Mochovce National Radioactive Waste Repository is a surface multi-barrier type storage facility for solid and treated solidified radioactive wastes generated from the Slovak Republic nuclear power plants operation and decommissioning, research institutes, laboratories and hospitals. The Repository comprises a system of single- and double-row storage boxes. The first double-row is enclosed by a steel-structure building. The 18 x 6 x 5.5 m storage boxes are made of reinforced concrete. The wall thickness is 600 mm. Two-double-rows, i.e. 80 storage boxes were built as part of Stage I (1 row = 20 storage boxes). Each storage box has a storage capacity of 90 fibre concrete containers of 3.1 m 3 volume. The total storage capacity is 7200 containers with the overall storage volume of 22320 m 3

  10. National Pesticide Standard Repository

    Science.gov (United States)

    EPA's National Pesticide Standards Repository collects and maintains an inventory of analytical “standards” of registered pesticides in the United States, as well as some that are not currently registered for food and product testing and monitoring.

  11. CAED Document Repository

    Science.gov (United States)

    Compliance Assurance and Enforcement Division Document Repository (CAEDDOCRESP) provides internal and external access of Inspection Records, Enforcement Actions, and National Environmental Protection Act (NEPA) documents to all CAED staff. The respository will also include supporting documents, images, etc.

  12. NIDDK Central Repository

    Data.gov (United States)

    U.S. Department of Health & Human Services — The NIDDK Central Repository stores biosamples, genetic and other data collected in designated NIDDK-funded clinical studies. The purpose of the NIDDK Central...

  13. NIA Aging Cell Repository

    Data.gov (United States)

    Federal Laboratory Consortium — To facilitate aging research on cells in culture, the NIA provides support for the NIA Aging Cell Repository, located at the Coriell Institute for Medical Research...

  14. Corticotropin, Repository Injection

    Science.gov (United States)

    ... injection is used to treat the following conditions:infantile spasms (seizures that usually begin during the first year ... tell how corticotropin repository injection works to treat infantile spasms.

  15. Planning the rad waste repository - Croatian case

    International Nuclear Information System (INIS)

    Kucar Dragicevic, S.; Subasic, D.; Lokner, V.

    1996-01-01

    Radioactive waste is generated in Croatia from various nuclear applications as well as from the Krsko NPP (Slovenian and Croatian joint venture facility). The national programme on radioactive waste management is aimed at straightening existing infrastructure, establishing new (more transparent) system of responsibilities and development of new legislation. The siting of LL/ILW repository is important segments of the whole radioactive waste management cycle. The status and efficiency of the rad waste management infrastructure in the country have the significant influence on all the activities related to the project of repository construction - from the very first phases of preliminary planning and background preparations to advanced phases of the project development. The present status of the Croatian national radioactive waste infrastructure and its influence on the repository project are presented. The role of national legislation and institutional framework are specially discussed. (author)

  16. Managing and Evaluating Digital Repositories

    Science.gov (United States)

    Zuccala, Alesia; Oppenheim, Charles; Dhiensa, Rajveen

    2008-01-01

    Introduction: We examine the role of the digital repository manager, discuss the future of repository management and evaluation and suggest that library and information science schools develop new repository management curricula. Method: Face-to-face interviews were carried out with managers of five different types of repositories and a Web-based…

  17. Radioactive waste repository study

    International Nuclear Information System (INIS)

    1978-11-01

    This is the first part of a report of a preliminary study for Atomic Energy of Canada Limited. It considers the requirements for an underground waste repository for the disposal of wastes produced by the Canadian Nuclear Fuel Program. The following topics are discussed with reference to the repository: 1) underground layout, 2) cost estimates, 3) waste handling, 4) retrievability, decommissioning, sealing and monitoring, and 5) research and design engineering requirements. (author)

  18. Reaction of glass during gamma irradiation in a saturated tuff environment. Part 1. SRL 165 glass

    Energy Technology Data Exchange (ETDEWEB)

    Bates, J.K.; Fischer, D.F.; Gerding, T.J.

    1986-02-01

    The influence of gamma irradiation on the reaction of actinide-doped borosilicate glass (SRL 165) in a saturated tuff environment has been studied in a series of tests lasting up to 56 days. The following conclusions were reached. The reaction of, and subsequent actinide release from, the glass depends on the dynamic interaction between radiolysis effects, which cause the solution pH to become more acidic; glass reaction, which drives the pH more basic; and test component interactions that may extract glass components from solution. The use of large gamma irradiation dose rates to accelerate reactions that may occur in an actual repository radiation field may affect this dynamic balance by unduly influencing the mechanism of the glass-water reaction. Comparisons between the present results and data obtained by reacting similar glasses using MCC-1 and NNWSI rock cup procedures indicate that the irradiation conditions used in the present experiments do not dramatically influence the reaction rate of the glass. 8 figs., 9 tabs.

  19. Permeameter studies of water flow through cement and clay borehole seals in granite, basalt and tuff

    Energy Technology Data Exchange (ETDEWEB)

    South, D.L.; Daemen, J.J.K.

    1986-10-01

    Boreholes near a repository must be sealed to prevent rapid migration of radionuclide-contaminated water to the accessible environment. The objective of this research is to assess the performance of borehole seals under laboratory conditions, particularly with regard to varying stress fields. Flow through a sealed borehole is compared with flow through intact rock. Cement or bentonite seals have been tested in granite, basalt, and welded tuff. The main conclusion is that under laboratory conditions, existing commercial materials can form high quality seals. Triaxial stress changes about a borehole do not significantly affect seal performance if the rock is stiffer than the seal. Temperature but especially moisture variations (drying) significantly degrade the quality of cement seals. Performance partially recovers upon resaturation. A skillfully sealed borehole may be as impermeable as the host rock. Analysis of the influence of relative seal-rock permeabilities shows that a plug with permeability one order of magnitude greater than that of the rock results in a flow increase through the hole and surrounding rock of only 1-1/2 times compared to the undisturbed rock. Since a borehole is only a small part of the total rock mass, the total effect is even less pronounced. The simplest and most effective way to decrease flow through a rock-seal system is to increase the seal length, assuming it can be guaranteed that no dominant by-pass flowpath through the rock exists.

  20. The Hydrogeologic Character of the Lower Tuff Confining Unit and the Oak Springs Butte Confining Unit in the Tuff Pile Area of Central Yucca Flat

    Energy Technology Data Exchange (ETDEWEB)

    Drellack, Jr., Sigmund L.; Prothro, Lance B.; Gonzales, Jose L.; Mercadante, Jennifer M.

    2010-07-30

    The lower tuff confining unit (LTCU) in the Yucca Flat Corrective Action Unit (CAU) consists of a monotonous sequence of pervasively zeolitized volcanic tuff (i.e., mostly bedded with lesser nonwelded to poorly welded tuff; not fractured) (Bechtel Nevada, 2006). The LTCU is an important confining unit beneath Yucca Flat because it separates the alluvial and volcanic aquifers, where many underground nuclear tests were conducted, from the regional lower carbonate aquifer. Recent sub-CAU-scale modeling by Los Alamos National Laboratory in the Tuff Pile area of Yucca Flat (Boryta, et al., in review) includes postulated low-porosity, high-permeability zones (i.e., fractured welded-tuff aquifers) within the LTCU. This scenario indicates that such postulated low-porosity, high-permeability zones could provide fast-path lateral conduits to faults, and eventually to the lower carbonate aquifer. A fractured and faulted lower carbonate aquifer is postulated to provide a flow path(s) for underground test-derived contaminants to potential offsite receptors. The ramifications of such a scenario are obvious for groundwater flow and contaminant migration beneath Yucca Flat. This paper describes the reasoning for not including postulated low-porosity, high-permeability zones within the LTCU in the Tuff Pile area or within the LTCU in the Yucca Flat CAU-scale model. Both observational and analytical data clearly indicate that the LTCU in the Tuff Pile area consists of pervasively zeolitic, nonwelded to poorly welded tuffs that are classified as tuff confining units (i.e., high-porosity, low-permeability). The position regarding the LTCU in the Tuff Pile area is summarized as follows: • The LTCU in the Tuff Pile area consists of a monotonous sequence of predominantly zeolitic nonwelded to poorly welded tuffs, and thus is accurately characterized hydrogeologically as a tuff confining unit (aquitard) in the Yucca Flat-Climax Mine hydrostratigraphic framework model (Bechtel Nevada

  1. Natural geochemical analogues of the near field of high-level nuclear waste repositories

    International Nuclear Information System (INIS)

    Apps, J.A.

    1995-01-01

    United States practice has been to design high-level nuclear waste (HLW) geological repositories with waste densities sufficiently high that repository temperatures surrounding the waste will exceed 100 degrees C and could reach 250 degrees C. Basalt and devitrified vitroclastic tuff are among the host rocks considered for waste emplacement. Near-field repository thermal behavior and chemical alteration in such rocks is expected to be similar to that observed in many geothermal systems. Therefore, the predictive modeling required for performance assessment studies of the near field could be validated and calibrated using geothermal systems as natural analogues. Examples are given which demonstrate the need for refinement of the thermodynamic databases used in geochemical modeling of near-field natural analogues and the extent to which present models can predict conditions in geothermal fields

  2. Specific surface area of a crushed welded tuff before and after aqueous dissolution

    Science.gov (United States)

    Reddy, M.M.; Claassen, H.C.

    1994-01-01

    Specific surface areas were measured for several reference minerals (anorthoclase, labradorite and augite), welded tuff and stream sediments from Snowshoe Mountain, near Creede, Colorado. Crushed and sieved tuff had an unexpectedly small variation in specific surface area over a range of size fractions. Replicate surface area measurements of the largest and smallest tuff particle size fractions examined (1-0.3 mm and <0.212 mm) were 2.3 ?? 0.2 m2/g for each size fraction. Reference minerals prepared in the same way as the tuff had smaller specific surface areas than that of the tuff of the same size fraction. Higher than expected tuff specific surface areas appear to be due to porous matrix. Tuff, reacted in solutions with pH values from 2 to 6, had little change in specific surface area in comparison with unreacted tuff. Tuff, reacted with solutions having high acid concentrations (0.1 M hydrochloric acid or sulfuric-hydrofluoric acid), exhibited a marked increase in specific surface area compared to unreacted tuff. ?? 1994.

  3. Numerical simulation of air- and water-flow experiments in a block of variably saturated, fractured tuff from Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Kwicklis, E.M.; Healy, R.W. [Geological Survey, Denver, CO (United States); Thamir, F. [AMX International, Inc., Denver, CO (United States); Hampson, D. [EQE International, Evergreen, CO (United States)

    1998-11-01

    Numerical models of water movement through variably saturated, fractured tuff have undergone little testing against experimental data collected from relatively well-controlled and characterized experiments. This report used the results of a multistage experiment on a block of variably saturated, fractured, welded tuff and associated core samples to investigate if those results could be explained using models and concepts currently used to simulate water movement in variably saturated, fractured tuff at Yucca Mountain, Nevada, the potential location of a high-level nuclear-waste repository. Aspects of the experiment were modeled with varying degrees of success. Imbibition experiments performed on cores of various lengths and diameters were adequately described by models using independently measured permeabilities and moisture-characteristic curves, provided that permeability reductions resulting from the presence of entrapped air were considered. Entrapped gas limited maximum water saturations during imbibition to approximately 0.70 to 0,80 of the fillable porosity values determined by vacuum saturation. A numerical simulator developed for application to fluid flow problems in fracture networks was used to analyze the results of air-injection tests conducted within the tuff block through 1.25-cm-diameter boreholes. These analyses produced estimates of transmissivity for selected fractures within the block. Transmissivities of other fractures were assigned on the basis of visual similarity to one of the tested fractures. The calibrated model explained 53% of the observed pressure variance at the monitoring boreholes (with the results for six outliers omitted) and 97% of the overall pressure variance (including monitoring and injection boreholes) in the subset of air-injection tests examined.

  4. Evaluation of past and future alterations in tuff at Yucca Mountain, Nevada, based on the clay mineralogy of drill cores USW G-1, G-2, and G-3

    International Nuclear Information System (INIS)

    Bish, D.L.

    1989-03-01

    The tuffs at Yucca Mountain in south-central Nevada are being studied by the Yucca Mountain Project (YMP) to determine their suitability for a high-level radioactive waste repository. For predictive purposes, it is important to understand the alteration history of Yucca Mountain and to know how the minerals in Yucca Mountain tuffs respond to changing conditions such as elevated temperatures. The clay mineralogy of these tuffs has been examined using x-ray powder diffraction, and approximation temperatures of alteration have been determined using available clay mineral data and fluid inclusion analyses. Also, several illites from drill holes USW G-1 and G-2 have been dated using K/Ar techniques, yielding ages of about 11 Myr. The clay mineral in Yucca Mountain tuffs are predominantly interstratified illite/smectites, with minor amounts of chloride, kaolinite, and interstratified chlorite/smectite at depth in USW G-1 and G-2. The reactions observed for these illite/smectites are similar to those observed in pelitic rocks. With depths, the illite/smectites transform from random interstratifications (R = 0) through ordered intermediates (R = 1) to illite in USW G-2 and to Kalkberg (R ≥ 3) interstratifications in USW G-1. The illite/smectites in USW G-3 have not significantly transformed. It appears that the illites in deeper rock results from hydrothermal and diagenetic reactions of earlier-formed smectites. These data demonstrate that the rocks at depth in the northern end of Yucca Mountain were significantly altered about 11 Myr ago. Both clay mineralogy and fluid inclusions suggest that the rocks at depth in USW G-2 have been subjected to postdepositional temperatures of at least 275/degree/C, those in USW G-1 have reached 200/degree/C, and USW G-3 rocks probably have not exceeded 100/degree/C. 64 refs., 9 figs., 3 tabs

  5. Measuring and Modeling Flow in Welded Fractured Tuffs

    International Nuclear Information System (INIS)

    R. Salve; C. Doughty; J.S. Wang

    2001-01-01

    We have carried out a series of in situ liquid-release experiments in conjunction with a numerical modeling study to examine the effect of the rock matrix on liquid flow and transport occurring primarily through the fracture network. Field experiments were conducted in the highly fractured Topopah Spring welded tuff at a site accessed from the Exploratory Studies Facility (ESFS), an underground laboratory in the unsaturated zone at Yucca Mountain, Nevada. During the experiment, wetting-front movement, flow-field evolution, and drainage of fracture flow paths were evaluated. Modeling was used to aid in experimental design, predict experimental results, and study the physical processes accompanying liquid flow through unsaturated fractured welded tuff. Field experiments and modeling suggest that it may not be sufficient to conceptualize the fractured tuff as consisting of a single network of high-permeability fractures embedded in a low-permeability matrix. The need to include a secondary fracture network is demonstrated by comparison to the liquid flow observed in the field

  6. Selenite transport in unsaturated tuff from Yucca Mountain

    International Nuclear Information System (INIS)

    Conca, J.L.; Triay, I.R.

    1994-01-01

    Direct measurements of unsaturated selenite retardation coefficients and unsaturated hydraulic conductivity were obtained on two tuff samples from Yucca Mountain using the UFA trademark technology. The retardation factor for the selenite species was only 2.5 in both Yucca Mountain vitric member at 62.6% saturation and zeolitized nonwelded tuff from G-tunnel at 52.8% saturation with respect to J-13 well water from the Nevada Test Site contaminated with selenium at 1.31 mg/l (ppm). In batch tests on the same material using 1.2 mg/l (ppm), the average K d was determined to be 13, giving retardation factors higher than the UFA column breakthrough tests by an order of magnitude. The difference could result from preferential flow paths in the UFA column as might occur in the field or differences in residence times between the two types of test. The unsaturated hydraulic conductivities during the experiments were 2.49 x 10 -8 cm/s for the Yucca Mountain vitric member and 1.16 x 10 -8 cm/s for the zeolitized nonwelded tuff

  7. Trust in Digital Repositories

    Directory of Open Access Journals (Sweden)

    Elizabeth Yakel

    2013-06-01

    Full Text Available ISO 16363:2012, Space Data and Information Transfer Systems - Audit and Certification of Trustworthy Digital Repositories (ISO TRAC, outlines actions a repository can take to be considered trustworthy, but research examining whether the repository’s designated community of users associates such actions with trustworthiness has been limited. Drawing from this ISO document and the management and information systems literatures, this paper discusses findings from interviews with 66 archaeologists and quantitative social scientists. We found similarities and differences across the disciplines and among the social scientists. Both disciplinary communities associated trust with a repository’s transparency. However, archaeologists mentioned guarantees of preservation and sustainability more frequently than the social scientists, who talked about institutional reputation. Repository processes were also linked to trust, with archaeologists more frequently citing metadata issues and social scientists discussing data selection and cleaning processes. Among the social scientists, novices mentioned the influence of colleagues on their trust in repositories almost twice as much as the experts. We discuss the implications our findings have for identifying trustworthy repositories and how they extend the models presented in the management and information systems literatures.

  8. Pretest thermal analysis of the Tuff Water Migration/In-Situ Heater Experiment

    International Nuclear Information System (INIS)

    Bulmer, B.M.

    1980-02-01

    This report describes the pretest thermal analysis for the Tuff Water Migration/In-Situ Heater Experiment to be conducted in welded tuff in G-tunnel, Nevada Test Site. The parametric thermal modeling considers variable boiling temperature, tuff thermal conductivity, tuff emissivity, and heater operating power. For nominal tuff properties, some near field boiling is predicted for realistic operating power. However, the extent of boiling will be strongly determined by the ambient (100% water saturated) rock thermal conductivity. In addition, the thermal response of the heater and of the tuff within the dry-out zone (i.e., bounded by boiling isotherm) is dependent on the temperature variation of rock conductivity as well as the extent of induced boiling

  9. Repository design concepts

    International Nuclear Information System (INIS)

    Mogg, C.S.

    1994-01-01

    This paper describes the development of a deep hard rock repository design from an initial generic approach through to a Sellafield site-specific preferred concept. As in the development of any engineering project, certain key requirements have been defined. For the repository these are that the design shall be robust in terms of safety, both during the construction and operational periods, providing maximum protection for the workforce and general public. It shall satisfy the requirements for long-term radiological safety laid down by the Department of the Environment and, as far as possible, incorporate technology and equipment which is already in use elsewhere. This will minimize the risks associated with new developments and provide opportunity to draw on expertise acquired by existing users. The repository project will inevitably involve engineering challenges not encountered in the design of other types of nuclear facility. (Author)

  10. Geohydrological simulation of a deep coastal repository

    International Nuclear Information System (INIS)

    Follin, S.

    1995-12-01

    This conceptual-numerical study treats the dewatering and resaturation phases associated with the construction, use and closure of a coastal nuclear waste repository located at depth in sparsely fractured Baltic Shield rocks. The main objective is to simulate the extent and duration of saline intrusion for a reasonable set of geohydrological assumptions. Long-term changes in the chemical environment associated with saline intrusion may affect the properties of the buffer zone material (bentonite). The first part of the study deals with history matching of a simple model geometry and the second part treats the dewatering and resaturation phases of the simulated repository. The history matching supports the standpoint that the occurrence of saline ground water reflects an ongoing but incomplete Holocene flushing of the Baltic Shield. The drawdown after fifty years of dewatering is highly dependent on the permeability of the excavated damaged zone. If the permeability close the repository is unaltered the entire region between the top side of the model and the repository is more or less partially saturated at the end of the simulation period. The simulations of a fifty year long recovery period suggest that the distribution between fresh and saline ground waters may be quite close to the conditions prior to the dewatering phase already after fifty years of closure despite an incomplete pressure recovery, which is an interesting result considering the objective of the study. 12 refs

  11. Safeguards for geological repositories

    International Nuclear Information System (INIS)

    Fattah, A.

    2000-01-01

    Direct disposal of spent nuclear fuel in geological repositories is a recognised option for closing nuclear fuel cycles. Geological repositories are at present in stages of development in a number of countries and are expected to be built and operated early next century. A State usually has an obligation to safely store any nuclear material, which is considered unsuitable to re-enter the nuclear fuel cycle, isolated from the biosphere. In conjunction with this, physical protection has to be accounted for to prevent inadvertent access to such material. In addition to these two criteria - which are fully under the State's jurisdiction - a third criterion reflecting international non-proliferation commitments needs to be addressed. Under comprehensive safeguards agreements a State concedes verification of nuclear material for safeguards purposes to the IAEA. The Agency can thus provide assurance to the international community that such nuclear material has been used for peaceful purposes only as declared by the State. It must be emphasised that all three criteria mentioned constitute a 'unit'. None can be sacrificed for the sake of the other, but compromises may have to be sought in order to make their combination as effective as possible. Based on comprehensive safeguards agreements signed and ratified by the State, safeguards can be terminated only when the material has been consumed or diluted in such a way that it can no longer be utilised for any nuclear activities or has become practicably irrecoverable. As such safeguards for nuclear material in geological repositories have to be continued even after the repository has been back-filled and sealed. The effective application of safeguards must assure continuity-of-knowledge that the nuclear material in the repository has not been diverted for an unknown purpose. The nuclear material disposed in a geological repository may eventually have a higher and long term proliferation risk because the inventory is

  12. Observation of time dependent dispersion in laboratory scale experiments with intact tuff

    International Nuclear Information System (INIS)

    Rundberg, R.S.; Triay, I.R.; Ott, M.A.; Mitchell, A.J.

    1989-01-01

    The migration of radionuclides through intact tuff was studied using tuff from Yucca Mountain, Nevada. The tuff samples were both highly zeolitized ash-fall tuff from the Calico Hills and densely welded devitrified tuff from the Topopah Springs member of the Paintbrush tuff. Tritiated water and pertechnetate were used as conservative tracers. The sorbing tracers 85 Sr, 137 Cs, and 133 Ba were used with the devitrified tuff only. Greater tailing in the elution curves of the densely welded tuff samples was observed that could be fit by adjusting the dispersion coefficient in the conventional Advection Dispersion Equation, ADE. The curves could be fit using time dependent dispersion as was previously observed for sediments and alluvium by Dieulin, Matheron, and de Marsily. The peak of strontium concentration was expected to arrive after 1.5 years based on the conventional ADE and assuming a linear K d of 26 ml/g. The observed elution had significant strontium in the first sample taken at 2 weeks after injection. The peak in the strontium elution occurred at 5 weeks. The correct arrival time for the strontium peak was achieved using a one dimensional analytic solution with time dependent dispersion. The dispersion coefficient as a function of time used to fit the conservative tracers was found to predict the peak arrival of the sorbing tracers. The K d used was the K d determined by the batch method on crushed tuff. 23 refs., 9 figs., 2 tabs

  13. Radionuclides in hydrothermal systems as indicators of repository conditions

    International Nuclear Information System (INIS)

    Wollenberg, H.A.; Flexser, S.; Smith, A.R.

    1990-11-01

    Hydrothermal systems in tuffaceous and older sedimentary rocks contain evidence of the interaction of radionuclides in fluids with rock matrix minerals and with materials lining fractures, in settings somewhat analogous to the candidate repository site at Yucca Mountain, NV. Earlier studies encompassed the occurrences of U and Th in a ''fossil'' hydrothermal system in tuffaceous rock of the San Juan Mountains volcanic field, CO. More recent and ongoing studies examine active hydrothermal systems in calderas at Long Valley, CA and Valles, NM. At the Nevada Test Site, occurrences of U and Th in fractured and unfractured rhyolitic tuff that was heated to simulate the introduction of radioactive waste are also under investigation. Observations to date suggest that U is mobile in hydrothermal systems, but that localized reducing environments provided by Fe-rich minerals and/or carbonaceous material concentrate U and thus attenuate its migration. 11 refs., 6 figs., 1 tab

  14. Salt repository design approach

    International Nuclear Information System (INIS)

    Matthews, S.C.

    1983-01-01

    This paper presents a summary discussion of the approaches that have been and will be taken in design of repository facilities for use with disposal of radioactive wastes in salt formations. Since specific sites have yet to be identified, the discussion is at a general level, supplemented with illustrative examples where appropriate. 5 references, 1 figure

  15. CRIS and Institutional Repositories

    Directory of Open Access Journals (Sweden)

    A Asserson

    2010-04-01

    Full Text Available CRIS (Current Research Information Systems provide researchers, research managers, innovators, and others with a view over the research activity of a domain. IRs (institutional repositories provide a mechanism for an organisation to showcase through OA (open access its intellectual property. Increasingly, organizations are mandating that their employed researchers deposit peer-reviewed published material in the IR. Research funders are increasingly mandating that publications be deposited in an open access repository: some mandate a central (or subject-based repository, some an IR. In parallel, publishers are offering OA but replacing subscription-based access with author (or author institution payment for publishing. However, many OA repositories have metadata based on DC (Dublin Core which is inadequate; a CERIF (Common-European Research Information Format CRIS provides metadata describing publications with formal syntax and declared semantics thus facilitating interoperation or homogeneous access over heterogeneous sources. The formality is essential for research output metrics, which are increasingly being used to determine future funding for research organizations.

  16. Radioactive waste repository study

    International Nuclear Information System (INIS)

    1978-11-01

    This is the third part of a report of a preliminary study for AECL. It summarizes the topics considered in reports AECL-6188-1 and AECL-6188-2 as requirements for an undergpound repository for disposal of wastes produced by the Canadian Nuclear Fuel Program. (author)

  17. The Computational Materials Repository

    DEFF Research Database (Denmark)

    Landis, David D.; Hummelshøj, Jens S.; Nestorov, Svetlozar

    2012-01-01

    The possibilities for designing new materials based on quantum physics calculations are rapidly growing, but these design efforts lead to a significant increase in the amount of computational data created. The Computational Materials Repository (CMR) addresses this data challenge and provides...... a software infrastructure that supports the collection, storage, retrieval, analysis, and sharing of data produced by many electronic-structure simulators....

  18. Low level waste repositories

    International Nuclear Information System (INIS)

    Hill, P.R.H.; Wilson, M.A.

    1983-11-01

    Factors in selecting a site for low-level radioactive waste disposal are discussed. South Australia has used a former tailings dam in a remote, arid location as a llw repository. There are also low-level waste disposal procedures at the Olympic Dam copper/uranium project

  19. WIPP Repository Reconfiguration

    Science.gov (United States)

    On August 30, 2011, the U.S. Department of Energy (DOE) provided a proposed planned change request that will relocate Panels 9 and 10 from the main north-south access drifts to south of the existing Panels 4 and 5 in the WIPP repository.

  20. Petrologic and geochemical characterization of the Topopah Spring Member of the Paintbrush Tuff: outcrop samples used in waste package experiments

    Energy Technology Data Exchange (ETDEWEB)

    Knauss, K.G.

    1984-06-01

    This report summarizes characterization studies conducted with outcrop samples of Topopah Spring Member of the Paintbrush Tuff (Tpt). In support of the Waste Package Task within the Nevada Nuclear Waste Storage Investigation (NNWSI), Tpt is being studied both as a primary object and as a constituent used to condition water that will be reacted with waste form, canister, or packing material. These studies directly or indirectly support NNWSI subtasks concerned with waste package design and geochemical modeling. To interpret the results of subtask experiments, it is necessary to know the exact nature of the starting material in terms of the intial bulk composition, mineralogy, and individual phase geochemistry. 31 figures, 5 tables.

  1. Petrologic and geochemical characterization of the Topopah Spring Member of the Paintbrush Tuff: outcrop samples used in waste package experiments

    International Nuclear Information System (INIS)

    Knauss, K.G.

    1984-06-01

    This report summarizes characterization studies conducted with outcrop samples of Topopah Spring Member of the Paintbrush Tuff (Tpt). In support of the Waste Package Task within the Nevada Nuclear Waste Storage Investigation (NNWSI), Tpt is being studied both as a primary object and as a constituent used to condition water that will be reacted with waste form, canister, or packing material. These studies directly or indirectly support NNWSI subtasks concerned with waste package design and geochemical modeling. To interpret the results of subtask experiments, it is necessary to know the exact nature of the starting material in terms of the intial bulk composition, mineralogy, and individual phase geochemistry. 31 figures, 5 tables

  2. Joint Battlespace Infosphere Repository Prototype

    National Research Council Canada - National Science Library

    McCabe, Patrick

    2003-01-01

    .... The approach was to leverage in-house research and development for repository design and core service definition as points of departure for a far term design. Several repository software packages were evaluated to aid in the definition of the design space for the JBI repository prototype.

  3. Radiation chemical effects in experiments to study the reaction of glass in an environment of gamma-irradiated air, groundwater, and tuff

    International Nuclear Information System (INIS)

    Van Konynenburg, R.A.

    1986-01-01

    The results of experiments performed by John K. Bates et al. on the reaction of nuclear waste glass with a gamma-irradiated 90 0 C aqueous solution were analyzed using theory developed from past research in radiation chemistry. The aqueous solution they used is similar to what would be expected in a water-saturated environment in a nuclear waste repository in tuff. The purpose of our study was to develop an understanding of the radiation-chemical processes that occurred in the Bates et al. experiments so the results could be applied to the design and performance analysis of a proposed repository in unsaturated tuff in Nevada. For the Bates et al. experiments at the highest dose (269 Mrad), which originally contained about 16 ml of ''equilibrated'' water taken from Nevada Test Site Well J-13 and 5.4 ml of air, we predicted that water decomposition to H 2 and O 2 would produce a pressure increase of at least 1.0 MPa at 20 0 C. We also predicted that nitrogen fixation from the air would occur, producing an increase of 1.6 x 10 -4 M in total fixed nitrogen concentration in solution. In addition, an equimolar production of H + would occur, which would be buffered by the HCO 3 - in the water. The fixed nitrogen in solution was predicted to be present as NO 2 - and NO 3 - with the ratio influenced by the presence of materials catalytic to the decomposition of H 2 O 2 . We found reasonable agreement between our predictions and the observations of Bates et al., where comparisons were possible. We apply the results to the proposed Nevada repository to the degree possible, given the different expected conditions

  4. Analysis of Conservative Tracer Tests in the Bullfrog, Tram, and Prow Pass Tuffs, 1996 to 1998, Yucca Mountain, Nye County, Nevada

    Science.gov (United States)

    Umari, Amjad; Fahy, Michael F.; Earle, John D.; Tucci, Patrick

    2008-01-01

    To evaluate the potential for transport of radionuclides in ground water from the proposed high-level nuclear-waste repository at Yucca Mountain, Nevada, conservative (nonsorbing) tracer tests were conducted among three boreholes, known as the C-hole Complex, and values for transport (or flow) porosity, storage (or matrix) porosity, longitudinal dispersivity, and the extent of matrix diffusion were obtained. The C-holes are completed in a sequence of Miocene tuffaceous rock, consisting of nonwelded to densely welded ash-flow tuff with intervals of ash-fall tuff and volcaniclastic rocks, covered by Quaternary alluvium. The lower part of the tuffaceous-rock sequence includes the Prow Pass, Bullfrog, and Tram Tuffs of the Crater Flat Group. The rocks are pervaded by tectonic and cooling fractures. Paleozoic limestone and dolomite underlie the tuffaceous rocks. Four radially convergent and one partially recirculating conservative (nonsorbing) tracer tests were conducted at the C-hole Complex from 1996 to 1998 to establish values for flow porosity, storage porosity, longitudinal dispersivity, and extent of matrix diffusion in the Bullfrog and Tram Tuffs and the Prow Pass Tuff. Tracer tests included (1) injection of iodide into the combined Bullfrog-Tram interval; (2) injection of 2,6 difluorobenzoic acid into the Lower Bullfrog interval; (3) injection of 3-carbamoyl-2-pyridone into the Lower Bullfrog interval; and (4) injection of iodide and 2,4,5 trifluorobenzoic acid, followed by 2,3,4,5 tetrafluorobenzoic acid, into the Prow Pass Tuff. All tracer tests were analyzed by the Moench single- and dual-porosity analytical solutions to the advection-dispersion equation or by superposition of these solutions. Nonlinear regression techniques were used to corroborate tracer solution results, to obtain optimal parameter values from the solutions, and to quantify parameter uncertainty resulting from analyzing two of the three radially convergent conservative tracer tests

  5. Geology of the Yucca Mountain Region, Chapter in Stuckless, J.S., ED., Yucca Mountain, Nevada - A Proposed Geologic Repository for High-Level Radioactive Waste

    Energy Technology Data Exchange (ETDEWEB)

    J.S. Stuckless; D. O' Leary

    2006-09-25

    Yucca Mountain has been proposed as the site for the Nation's first geologic repository for high-level radioactive waste. This chapter provides the geologic framework for the Yucca Mountain region. The regional geologic units range in age from late Precambrian through Holocene, and these are described briefly. Yucca Mountain is composed dominantly of pyroclastic units that range in age from 11.4 to 15.2 Ma. The proposed repository would be constructed within the Topopah Spring Tuff, which is the lower of two major zoned and welded ash-flow tuffs within the Paintbrush Group. The two welded tuffs are separated by the partly to nonwelded Pah Canyon Tuff and Yucca Mountain Tuff, which together figure prominently in the hydrology of the unsaturated zone. The Quaternary deposits are primarily alluvial sediments with minor basaltic cinder cones and flows. Both have been studied extensively because of their importance in predicting the long-term performance of the proposed repository. Basaltic volcanism began about 10 Ma and continued as recently as about 80 ka with the eruption of cones and flows at Lathrop Wells, approximately 10 km south-southwest of Yucca Mountain. Geologic structure in the Yucca Mountain region is complex. During the latest Paleozoic and Mesozoic, strong compressional forces caused tight folding and thrust faulting. The present regional setting is one of extension, and normal faulting has been active from the Miocene through to the present. There are three major local tectonic domains: (1) Basin and Range, (2) Walker Lane, and (3) Inyo-Mono. Each domain has an effect on the stability of Yucca Mountain.

  6. Geology of the Yucca Mountain Region, Chapter in Stuckless, J.S., ED., Yucca Mountain, Nevada - A Proposed Geologic Repository for High-Level Radioactive Waste

    International Nuclear Information System (INIS)

    J.S. Stuckless; D. O'Leary

    2006-01-01

    Yucca Mountain has been proposed as the site for the Nation's first geologic repository for high-level radioactive waste. This chapter provides the geologic framework for the Yucca Mountain region. The regional geologic units range in age from late Precambrian through Holocene, and these are described briefly. Yucca Mountain is composed dominantly of pyroclastic units that range in age from 11.4 to 15.2 Ma. The proposed repository would be constructed within the Topopah Spring Tuff, which is the lower of two major zoned and welded ash-flow tuffs within the Paintbrush Group. The two welded tuffs are separated by the partly to nonwelded Pah Canyon Tuff and Yucca Mountain Tuff, which together figure prominently in the hydrology of the unsaturated zone. The Quaternary deposits are primarily alluvial sediments with minor basaltic cinder cones and flows. Both have been studied extensively because of their importance in predicting the long-term performance of the proposed repository. Basaltic volcanism began about 10 Ma and continued as recently as about 80 ka with the eruption of cones and flows at Lathrop Wells, approximately 10 km south-southwest of Yucca Mountain. Geologic structure in the Yucca Mountain region is complex. During the latest Paleozoic and Mesozoic, strong compressional forces caused tight folding and thrust faulting. The present regional setting is one of extension, and normal faulting has been active from the Miocene through to the present. There are three major local tectonic domains: (1) Basin and Range, (2) Walker Lane, and (3) Inyo-Mono. Each domain has an effect on the stability of Yucca Mountain

  7. Thermal Conductivity of the Potential Repository Horizon Model Report

    International Nuclear Information System (INIS)

    Ramsey, J.

    2002-01-01

    The purpose of this report is to assess the spatial variability and uncertainty of thermal conductivity in the host horizon for the proposed repository at Yucca Mountain. More specifically, the lithostratigraphic units studied are located within the Topopah Spring Tuff (Tpt) and consist of the upper lithophysal zone (Tptpul), the middle nonlithophysal zone (Tptpmn), the lower lithophysal zone (Tptpll), and the lower nonlithophysal zone (Tptpln). The Tptpul is the layer directly above the repository host layers, which consist of the Tptpmn, Tptpll, and the Tptpln. Current design plans indicate that the largest portion of the repository will be excavated in the Tptpll (Board et al. 2002 [157756]). The main distinguishing characteristic among the lithophysal and nonlithophysal units is the percentage of large scale (cm-m) voids within the rock. The Tptpul and Tptpll, as their names suggest, have a higher percentage of lithophysae than the Tptpmn and the Tptpln. Understanding the influence of the lithophysae is of great importance to understanding bulk thermal conductivity and perhaps repository system performance as well. To assess the spatial variability and uncertainty of thermal conductivity, a model is proposed that is functionally dependent on the volume fraction of lithophysae and the thermal conductivity of the matrix portion of the rock. In this model, void space characterized as lithophysae is assumed to be air-saturated under all conditions, while void space characterized as matrix may be either water- or air-saturated. Lithophysae are assumed to be air-saturated under all conditions since the units being studied are all located above the water table in the region of interest, and the relatively strong capillary forces of the matrix will, under most conditions, preferentially retain any moisture present in the rock

  8. Felsic tuff from Rutland Island – A pyroclastic flow deposit in ...

    Indian Academy of Sciences (India)

    : • white massive tuff with ill-defined bedding contacts (facies-A) and. • dominantly green tuff exhibiting well-developed turbidite sequence with up-section change from a massive unit to plane laminated units to ripple drift lamination (facies-B).

  9. Felsic tuff from Rutland Island–A pyroclastic flow deposit in Miocene ...

    Indian Academy of Sciences (India)

    : white massive tuff with ill-defined bedding contacts (facies-A) and; dominantly green tuff exhibiting well-developed turbidite sequence with up-section change from a massive unit to plane laminated units to ripple drift lamination (facies-B).

  10. Deformation and velocity measurements at elevated temperature in a fractured 0.5 M block of tuff

    International Nuclear Information System (INIS)

    Blair, S.C.; Berge, P.A.

    1996-01-01

    This paper presents preliminary results of laboratory tests conducted on small block samples of Topopah Spring tuff, in support of the Yucca Mountain Site Characterization Project. The overall objective of these tests is to investigate the thermal-mechanical, thermal-hydrological, and thermal-chemical response of the rock to conditions similar to the near-field environment (NFE) of a potential nuclear waste repository. We present preliminary results of deformation and elastic wave velocity measurements on a 0.5-m-scale block of Topopah Spring tuff tested in uniaxial compression to 8.5 MPa and at temperatures to 85 degree C. The Young's modulus was found to be about 7 to 31 GPa for vertical measurements parallel to the stress direction across parts of the block containing no fractures or a few fractures, and 0.5 to 0.9 GPA for measurements across individual fractures, at ambient temperature and 8.5 MPa maximum stress. During stress cycles between 5 and 8.5 MPa, the deformation modulus values for the matrix with fractures were near 15-20 GPa at ambient temperature but dropped to about 10 GPa at 85 degree C. Compressional wave velocities were found to be about 3.6 to 4.7 km/s at ambient temperature and stress. After the stress was cycled, velocities dropped to values as low as 2.6 km/s in the south end of the block where vertical cracks developed. Heating the block to about 85 degree C raised velocities to as much as 5.6 km/s in the upper third of the block

  11. Air-injection field tests to determine the effect of a heat cycle on the permeability of welded tuff

    International Nuclear Information System (INIS)

    Lee, K.H.; Ueng, Tzou-Shin.

    1991-01-01

    As part of a series of prototype tests conducted in preparation for site characterization of the potential nuclear-waste repository site at Yucca Mountain, Nevada, air-injection tests were conducted in the welded tuffs in G-Tunnel at the Nevada Test Site. The objectives were to characterize the permeability of the highly fractured tuff around a horizontal heater emplacement borehole, and to determine the effect of a heating and cooling cycle on the rock-mass permeability. Air was injected into packed-off intervals along the heater borehole. The bulk permeability of the rock adjacent to the test interval and the aperture of fractures intersecting the interval were computed from the air-flow rate, temperature, and pressure at steady state. The bulk permeability of intervals along with borehole varied from a minimum of 0.08 D to a maximum of over 144 D and the equivalent parallel-plate apertures of fractures intersecting the borehole varied from 70 to 589 μm. Higher permeabilities seemed to correlate spatially with the mapped fractures. The rock was then heated for a period of 6.5 months with an electrical-resistive heater installed in the borehole. After heating, the rock was allowed to cool down to the ambient temperature. The highest borehole wall temperature measured was 242 degree C. Air injection tests were repeated following the heating and cooling cycle, and the results showed significant increases in bulk permeability ranging from 10 to 1830% along the borehole. 8 ref., 6 figs., 3 tabs

  12. Sorption phenomena of modification of clinoptilolite tuffs by surfactant cations.

    Science.gov (United States)

    Rozić, M; Ivanec Sipusić, D; Sekovanić, L; Miljanić, S; Curković, L; Hrenović, J

    2009-03-15

    The sorption of cationic surfactant hexadecyltrimethylammonium (HDTMA) onto the solid/liquid interfaces of different clinoptilolite rich tuffs (CT) is examined. Examined were CT from Serbia with 75% clinoptilolite, CT from Turkey with 70% clinoptilolite, and CT from Croatia with 60% clinoptilolite. The sorption of HDTMA cations increased in the following order: CT from Serbia>CT from Turkey>CT from Croatia. The maximum amounts of sorbed HDTMA cations, normalized with regard to external cation exchange capacities of tuffs, were 1.79, 1.70, and 1.14 for Serbian, Turkish, and Croatian CT. FTIR analysis of samples with the maximum amount of sorbed HDTMA cations showed that HDTMA chains on Serbian CT adopt mainly a stretched all-trans conformation, while at the surfaces of CT from Turkey and Croatia the amount of gauche conformations increased. The zeta potentials of CT samples with the maximum amount of sorbed HDTMA cations and the sorption of benzoate anions on these samples increased in the following order: CT from Turkey>CT from Serbia>CT from Croatia. It can be assumed that on the surface of CT from Turkey iron (hydr)oxide clusters or nanoparticles with positive surface sites are present, due to which the isoelectric point is sifted toward lower and the zeta potential toward higher values. Therefore, the sorption of benzoate anions on modified CT from Turkey is also higher.

  13. Scaling behavior of gas permeability measurements in volcanic tuffs

    International Nuclear Information System (INIS)

    Tidwell, V.C.

    1994-01-01

    One of the critical issues facing the Yucca Mountain site characterization and performance assessment programs is the manner in which property scaling is addressed. Property scaling becomes an issue whenever heterogeneous media properties are measured at one scale but applied at another. A research program has been established to challenge current understanding of property scaling with the aim of developing and testing models that describe scaling behavior in a quantitative manner. Scaling of constitutive rock properties is investigated through physical experimentation involving the collection of suites of gas-permeability data measured over a range of discrete scales. The approach is to systematically isolate those factors believed to influence property scaling and investigate their relative contributions to overall scaling behavior. Two blocks of tuff, each exhibiting differing heterogeneity structure, have recently been examined. Results of the investigation show very different scaling behavior, as exhibited by changes in the distribution functions and variograms, for the two tuff samples. Even for the relatively narrow range of measurement scales employed significant changes in the distribution functions, variograms, and summary statistics occurred. Because such data descriptors will likely play an important role in calculating effective media properties, these results demonstrate both the need to understand and accurately model scaling behavior

  14. Colloid Facilitated Transport of Plutonium in Fractured Volcanic Tuff

    Science.gov (United States)

    Kersting, A. B.; Zhao, P.; Walensky, J. R.; Roberts, S. K.; Johnson, M. R.; Zavarin, M.; Ramon, E. C.

    2004-12-01

    The transport of low-solubility radionuclides in a colloidal- or colloidal bound state is frequently suspected or observed. Groundwater contaminated with radionuclides associated with underground nuclear tests was collected from several different well locations at the Nevada Test Site (NTS). In each case, the low-levels of plutonium detected in the groundwater were overwhelmingly (>95percent) associated with the colloidal and not the dissolved fraction of the groundwater. The colloidal fractions consisted of secondary minerals such as clays and zeolites. To better understand the mechanisms controlling the potential colloidal transport of plutonium, colloid-facilitated fracture flow laboratory experiments are being conducted. Pseudocolloids consisting of Pu(IV) sorbed to clinoptilolite were combined with a radionuclide solution cocktail consisting of Np, U, Cs, Sr, Sm and 3H and Re (analog to Tc) tracers in NTS-type synthetic groundwater (4.5mM NaHCO3-). The cocktail was injected into a smooth fracture in a volcanic tuff rock core from the NTS and the effluent analyzed. Autoradiography and secondary ion mass spectrometry will be used to understand the mineral -colloid-radionuclide interactions in the fracture volcanic tuff.

  15. Influence of deterministic geologic trends on spatial variability of hydrologic properties in volcanic tuff

    International Nuclear Information System (INIS)

    Rautman, C.A.; Flint, A.L.; Chornack, M.P.; Istok, J.D.

    1992-01-01

    Hydrologic properties have been measured on outcrop samples taken from a detailed, two-dimension grid covering a 1.4 km outcrop exposure of the 10-m thick non-welded-to-welded, shardy base microstratigraphic unit of the Tiva Canyon Member of the Miocene Paintbrush Tuff at Yucca Mountain, Nevada. These data allow quantification of spatial trends in rock matrix properties that exist in this important hydrologic unit. Geologic investigation, combined with statistical and geostatistical analyses of the numerical data, indicates that spatial variability of matrix properties is related to deterministic geologic processes that operated throughout the region. Linear vertical trends in hydrologic properties are strongly developed in the shardy base microstratigraphic unit, and they are more accurately modeled using the concept of a thickness-normalized stratigraphic elevation within the unit, rather than absolute elevation. Hydrologic properties appear to be correlated over distances of 0.25 to 0.3 of the unit thickness after removing the deterministic vertical trend. The use of stratigraphic elevation allows scaling of identified trends by unit thickness which may be of particular importance in a basal, topography-blanketing unit such as this one. Horizontal changes in hydrologic properties do not appear to form obvious trends within the limited lateral geographic extent of the ash-flow environment that was examined. Matrix properties appear to be correlated horizontally over distances between 100 and 400 m. The existence and quantitative description of these trends and patterns of vertical spatial continuity should increase confidence in models of hydrologic properties and groundwater flow in this area that may be constructed to support the design of a potential high-level nuclear waste repository at Yucca Mountain

  16. Measurements of matric and water potentials in unsaturated tuff at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Thamir, F.; McBride, C.M.

    1985-01-01

    Two types of instruments were installed in a borehole in order to monitor matric and water potentials of various hydrogeologic units consisting of tuff. The borehole was drilled as part of a study to provide information to the US Department of Energy for their use in evaluating Yucca Mountain, Nevada, for a repository for high-level radioactive waste. Heat-dissipation probes were used to monitor matric potentials and thermocouple psychrometers were used to monitor water potentials. Two major concerns regarding the use of these instruments in deep boreholes are: (1) the effect of length of the lead wires, and (2) the inability to recalibrate the instruments after installation. The length of the lead wire contributes to the source resistance and lead capacitance, which affects the signal settling time. Both instruments tested proved to be insensitive to lead-wire length, except when connected to smaller input-impedance data loggers. Thermocouple wires were more sensitive than heat-dissipation probe wires because of their greater resistance and quality of voltmeters used. Two thermocouple psychrometers were installed at every instrument station for backup and verification of data, because the instruments could not be recalibrated in situ. Multiple scanning rather than single-point scanning of the evaporation curve of a thermocouple psychrometer could give more reliable data, especially in differentiating between very wet and very dry environments. An isolated power supply needs to be used for each heat dissipation probe rather than a single power supply for a group of probes to avoid losing data from all probes when one probe malfunctions. This type of system is particularly desirable if the site is unattended by an operator for as long as a month. 20 refs., 13 figs., 2 tabs

  17. CONTACT ANGLE OF YUCCA MOUNTAIN WELDED TUFF WITH WATER AND BRINES

    International Nuclear Information System (INIS)

    H. Kalia

    2006-01-01

    A number of tests were performed to acquire contact angles between Yucca Mountain welded tuff from Topopah Springs Lower Lithophysal geologic unit and various brine solutions. The tests were performed on core disks received from Sample Management Facility (SMF), oven dried to a constant weight and the core disks vacuum saturated in: distilled water, J-13 water, calcium chloride brine and sodium chloride brine to constant weight. The contact angles were acquired from eight points on the surface of the core disks, four on rough surface, and four on polished surface. The contact angle was measured by placing a droplet of the test fluid, distilled water, J-13 water, calcium chloride brine and sodium chloride brine on the core disks. The objective of this test was to acquire contact angles as a potential input to estimating capillary forces in accumulated dust on the waste packages and drip shields slated for the proposed High-Level Radioactive Waste Repository at Yucca Mountain, Nevada. It was noted that once the droplet contacts the test surface, it continues to spread hence the contact angle continues to decrease with elapsed time. The maximum observed angle was at time 0 or when the drop contacted the rock surface. The measured contact angle, in all cases has significant scatter. In general, the time zero contact angles for core disks saturated in sodium chloride brine were smaller than those saturated in calcium chloride brine, distilled water, and J-13 water. The contact angles for samples saturated in distilled water, J-13 water and calcium chloride brine at time zero were similar. There was slight difference between the observed contact angles for smooth and rough surface of the test samples. The contact angles for smooth surfaces were smaller than for the rough surfaces

  18. Publishers and repositories

    CERN Multimedia

    CERN. Geneva

    2007-01-01

    The impact of self-archiving on journals and publishers is an important topic for all those involved in scholarly communication. There is some evidence that the physics arXiv has had no impact on physics journals, while 'economic common sense' suggests that some impact is inevitable. I shall review recent studies of librarian attitudes towards repositories and journals, and place this in the context of IOP Publishing's experiences with arXiv. I shall offer some possible reasons for the mis-match between these perspectives and then discuss how IOP has linked with arXiv and experimented with OA publishing. As well as launching OA journals we have co-operated with Cornell and the arXiv on Eprintweb.org, a platform that offers new features to repository users. View Andrew Wray's biography

  19. Two-phase unsaturated flow at Yucca Mountain, Nevada - A Report on Current Understanding

    International Nuclear Information System (INIS)

    Pruess, K.

    1998-01-01

    The U.S. civilian nuclear waste program is unique in its focus on disposal of high-level wastes in the unsaturated zone (UZ), above the water table. The potential repository site currently under investigation is located in a semi-arid region of the southwestern U.S. at Yucca Mountain, Nevada. The geology of the site consists of layered sequences of faulted, fractured, and bedded tuffs. The groundwater table is approximately 600 m beneath the land surface, while the proposed repository horizon is at a nominal depth of approximately 375 m. In this kind of environment, two-phase flow is not just a localized perturbation to natural conditions, as in the saturated zone, but is the predominant mode of water and gas flow. The purpose of this report is to review the current understanding of gas and water flow, and mass transport, in the unique hydrogeologic environment of Yucca Mountain. Characteristics of the Yucca Mountain site are examined, and concepts and mathematical modeling approaches are described for variably saturated flow in thick unsaturated zones of fractured rock. The paper includes a brief summary of the disposal concept and repository design, as developed by a team of engineering contractors to the U.S. Department of Energy (DOE), with strong participation from the DOE National Laboratories

  20. Staged Repository Development Programmes

    International Nuclear Information System (INIS)

    Isaacs, T

    2003-01-01

    Programs to manage and ultimately dispose of high-level radioactive wastes are unique from scientific and technological as well as socio-political aspects. From a scientific and technological perspective, high-level radioactive wastes remain potentially hazardous for geological time periods-many millennia-and scientific and technological programs must be put in place that result in a system that provides high confidence that the wastes will be isolated from the accessible environment for these many thousands of years. Of course, ''proof'' in the classical sense is not possible at the outset, since the performance of the system can only be known with assurance, if ever, after the waste has been emplaced for those geological time periods. Adding to this challenge, many uncertainties exist in both the natural and engineered systems that are intended to isolate the wastes, and some of the uncertainties will remain regardless of the time and expense in attempting to characterize the system and assess its performance. What was perhaps underappreciated in the early days of waste management and repository program development were the unique and intense reactions that the institutional, political, and public bodies would have to repository program development, particularly in programs attempting to identify and then select sites for characterization, design, licensing, and ultimate development. Reactions in most nations were strong, focused, unrelenting, and often successful in hindering, derailing, and even stopping national repository programs. The reasons for such reactions and the measures to successfully respond to them are still evolving and continue to be the focus of many national program and political leaders. Adaptive Staging suggests an approach to repository program development that reflects the unique challenges associated with the disposal of high-level radioactive waste. The step-wise, incremental, learn-as-you-go approach is intended to maximize the

  1. Evaluation of repository safety

    International Nuclear Information System (INIS)

    Sagar, B.; Patrick, W.; Dasgupta, B.; Mohanty, S.

    2002-01-01

    The United States high-level waste program requires evaluation of radiological safety during two distinct time intervals. The first interval, commonly referred to as the preclosure period, deals with receipt of waste at the site, transfer into disposal containers, if needed, emplacement in the underground openings, monitoring and maintenance activities, backfill and closure of the underground openings, and decontamination and decommissioning of the surface facilities of the geologic repository. The preclosure period may extend from a few tens of years to as long as a few hundred of years, depending on repository design and societal norms regarding a final decision to permanently seal the repository. During the preclosure or operational period, performance confirmation studies are conducted to provide a basis for updating and reevaluating estimates of postclosure performance and, finally, to provide a basis for a closure decision. The postclosure period during which expected repository performance must meet certain standards may range from ten thousands years, as it does in the United States, to millions of years, as it does in some European nations. Waste handling operations in the preclosure period are to be evaluated in relation to their potential effect on workers, members of general public, and the general environment. During this period, releases of radioactivity are to be monitored and appropriate actions taken whenever established limits are approached or exceeded. Preclosure safety is highly dependent on facility design, operational hardware and automated systems, operational sequences, and reliability of humans involved in operations. Preclosure safety analyses conducted before operations begin play a major role in the design process, selection of equipment, and development of operational procedures. Because of the complexity, duration, and spatial scales of the operations, analyses are conducted using mathematical models implemented in computer codes

  2. Towards Interoperable Preservation Repositories: TIPR

    Directory of Open Access Journals (Sweden)

    Priscilla Caplan

    2010-07-01

    Full Text Available Towards Interoperable Preservation Repositories (TIPR is a project funded by the Institute of Museum and Library Services to create and test a Repository eXchange Package (RXP. The package will make it possible to transfer complex digital objects between dissimilar preservation repositories.  For reasons of redundancy, succession planning and software migration, repositories must be able to exchange copies of archival information packages with each other. Every different repository application, however, describes and structures its archival packages differently. Therefore each system produces dissemination packages that are rarely understandable or usable as submission packages by other repositories. The RXP is an answer to that mismatch. Other solutions for transferring packages between repositories focus either on transfers between repositories of the same type, such as DSpace-to-DSpace transfers, or on processes that rely on central translation services.  Rather than build translators between many dissimilar repository types, the TIPR project has defined a standards-based package of metadata files that can act as an intermediary information package, the RXP, a lingua franca all repositories can read and write.

  3. National Geoscience Data Repository System. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Schiffries, C.M.; Milling, M.E.

    1994-03-01

    The American Geological Institute (AGI) has completed the first phase of a study to assess the feasibility of establishing a National Geoscience Data Repository System to capture and preserve valuable geoscientific data. The study was initiated in response to the fact that billions of dollars worth of domestic geological and geophysical data are in jeopardy of being irrevocably lost or destroyed as a consequence of the ongoing downsizing of the US energy and minerals industry. This report focuses on two major issues. First, it documents the types and quantity of data available for contribution to a National Geoscience Data Repository System. Second, it documents the data needs and priorities of potential users of the system. A National Geoscience Data Repository System would serve as an important and valuable source of information for the entire geoscience community for a variety of applications, including environmental protection, water resource management, global change studies, and basic and applied research. The repository system would also contain critical data that would enable domestic energy and minerals companies to expand their exploration and production programs in the United States for improved recovery of domestic oil, gas, and mineral resources.

  4. U.S. Department of Energy approaches to the assessment of radionuclide migration for the geologic repository program

    International Nuclear Information System (INIS)

    Luik, A.E. van; Apted, M.J.

    1988-01-01

    Potential radionuclide migration in geologic repositories is being addressed by the U.S. Department of Energy's Office of Civilian Radioactive Waste Management through its Office of Geologic Repositories (OGR). A diversity of geohydrologic settings is being investigated: unsaturated tuff, saturated basalt, and bedded salt. A number of approaches to assessing potential migration are being considered. Mass transfer is prominent among near-field approaches. For far-field analysis of migration in the geosphere, detailed characterizations of potential repository sites will lead to site-specific models describing radionuclide migration for a variety of postulated release scenarios. Finite-element and finite-difference codes are being used and developed to solve the mathematical equations pertinent to far-field assessments. Computational approaches presently in use generally require distribution coefficients to estimate the retardation of specific radionuclides with respect to the transport rate of water. 26 refs

  5. Distribution of potentially hazardous phases in the subsurface at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Guthrie, G.D. Jr.; Bish, D.L.; Chipera, S.J.; Raymond, R. Jr.

    1995-05-01

    Drilling, trenching, excavation of the Exploratory Studies Facility, and other surface and underground-distributing activities have the potential to release minerals into the environment from tuffs at Yucca Mountain, Nevada. Some of these minerals may be potential respiratory health hazards. Therefore, an understanding of the distribution of the minerals that may potentially be liberated during site-characterization and operation of the potential repository is crucial to ensuring worker and public safety. Analysis of previously reported mineralogy of Yucca Mountain tuffs using data and criteria from the International Agency for Research on Cancer (IARC) suggests that the following minerals are of potential concern: quartz, cristobalite, tridymite, opal-CT, erionite, mordenite, and palygorskite. The authors have re-evaluated the three-dimensional mineral distribution at Yucca Mountain above the static water level both in bulk-rock samples and in fractures, using quantitative X-ray powder diffraction analysis. Erionite, mordenite, and palygorskite occur primarily in fractures; the crystalline-silica minerals, quartz, cristobalite, and tridymite are major bulk-rock phases. Erionite occurs in the altered zone just above the lower Topopah Spring Member vitrophyre, and an occurrence below the vitrophyre but above the Calico Hills has recently been identified. In this latter occurrence, erionite is present in the matrix at levels up to 35 wt%. Mordenite and palygorskite occur throughout the vadose zone nearly to the surface. Opal-CT is limited to zeolitic horizons

  6. Distribution of potentially hazardous phases in the subsurface at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Guthrie, G.D. Jr.; Bish, D.L.; Chipera, S.J.; Raymond, R. Jr.

    1995-05-01

    Drilling, trenching, excavation of the Exploratory Studies Facility, and other surface and underground-distributing activities have the potential to release minerals into the environment from tuffs at Yucca Mountain, Nevada. Some of these minerals may be potential respiratory health hazards. Therefore, an understanding of the distribution of the minerals that may potentially be liberated during site-characterization and operation of the potential repository is crucial to ensuring worker and public safety. Analysis of previously reported mineralogy of Yucca Mountain tuffs using data and criteria from the International Agency for Research on Cancer (IARC) suggests that the following minerals are of potential concern: quartz, cristobalite, tridymite, opal-CT, erionite, mordenite, and palygorskite. The authors have re-evaluated the three-dimensional mineral distribution at Yucca Mountain above the static water level both in bulk-rock samples and in fractures, using quantitative X-ray powder diffraction analysis. Erionite, mordenite, and palygorskite occur primarily in fractures; the crystalline-silica minerals, quartz, cristobalite, and tridymite are major bulk-rock phases. Erionite occurs in the altered zone just above the lower Topopah Spring Member vitrophyre, and an occurrence below the vitrophyre but above the Calico Hills has recently been identified. In this latter occurrence, erionite is present in the matrix at levels up to 35 wt%. Mordenite and palygorskite occur throughout the vadose zone nearly to the surface. Opal-CT is limited to zeolitic horizons.

  7. Scientific data necessary to predict radionuclide migration within or near a mined nuclear repository

    International Nuclear Information System (INIS)

    Downs, W.F.

    1983-03-01

    The National Waste Terminal Storage Program was created to develop a system to isolate radioactive wastes from the biosphere. It has been determined that the most reasonable means for accomplishing this task is to place the high-level and transuranic wastes in mined geologic repositories. Three geologic environments have been selected for further study and evaluation: (1) domed or bedded salt formations, (2) thick basalt flows fo the Columbia River Plateau and (3) alkali igneous rocks, both tuffs and granites, of the Nevada Test Site. Each of these candidate geologies will present a different physical-chemical environment to the waste package. The physical environments have been estimated based on depth of repository, radionuclide loading, and spacing of canisters. The chemical environments are based on initial host-rock mineralogy, native ground-water geochemistry, and likely alteration assemblages. The latter sections of this report discuss the mechanisms of radionuclide release, transport, and retention on the host rocks or their alteration products

  8. NASA Biological Specimen Repository

    Science.gov (United States)

    McMonigal, K. A.; Pietrzyk, R. A.; Sams, C. F.; Johnson, M. A.

    2010-01-01

    The NASA Biological Specimen Repository (NBSR) was established in 2006 to collect, process, preserve and distribute spaceflight-related biological specimens from long duration ISS astronauts. This repository provides unique opportunities to study longitudinal changes in human physiology spanning may missions. The NBSR collects blood and urine samples from all participating ISS crewmembers who have provided informed consent. These biological samples are collected once before flight, during flight scheduled on flight days 15, 30, 60, 120 and within 2 weeks of landing. Postflight sessions are conducted 3 and 30 days after landing. The number of in-flight sessions is dependent on the duration of the mission. Specimens are maintained under optimal storage conditions in a manner that will maximize their integrity and viability for future research The repository operates under the authority of the NASA/JSC Committee for the Protection of Human Subjects to support scientific discovery that contributes to our fundamental knowledge in the area of human physiological changes and adaptation to a microgravity environment. The NBSR will institute guidelines for the solicitation, review and sample distribution process through establishment of the NBSR Advisory Board. The Advisory Board will be composed of representatives of all participating space agencies to evaluate each request from investigators for use of the samples. This process will be consistent with ethical principles, protection of crewmember confidentiality, prevailing laws and regulations, intellectual property policies, and consent form language. Operations supporting the NBSR are scheduled to continue until the end of U.S. presence on the ISS. Sample distribution is proposed to begin with selections on investigations beginning in 2017. The availability of the NBSR will contribute to the body of knowledge about the diverse factors of spaceflight on human physiology.

  9. INSTITUTIONAL REPOSITORY: EMPLOYMENT IN EDUCATION

    Directory of Open Access Journals (Sweden)

    Vasyl P. Oleksyuk

    2012-11-01

    Full Text Available The article investigated the concept of «institutional repository» and determined the aspects of institutional repositories in higher education. Institutional Repositories are information systems that allow preserving, storing and disseminating scientific knowledge produced in higher education and scientific research institutions. This study presented the main aspects using institutional repositories in educational process (such as storage of scientific and educational information, means of organization activity of students, object of studying. This article produced the structure of communities and collections of the institutional. It is described the experience of implementing of DSpace in the learning process.

  10. 40Ar/39Ar age spectra from the KBS Tuff, Koobi Fora Formation

    International Nuclear Information System (INIS)

    McDougall, I.

    1981-01-01

    40 Ar/ 39 Ar age spectra on anorthoclase phenocrysts from three pumice clasts in the KBS Tuff yield nearly ideal flat patterns, providing good evidence that the samples have remained undisturbed since crystallization. The ages are concordant at 1.88 = 0.02 Myr, and confirm that the KBS Tuff, a key marker bed in the Koobi Fora Formation, northern Kenya, is now very well dated. These results resolve the conflict between earlier 40 Ar/ 39 Ar and conventional K-Ar dating measurements on the KBS Tuff. (author)

  11. 40Ar/39Ar age spectra from the KBS Tuff, Koobi Fora Formation.

    Science.gov (United States)

    McDougall, Ian

    1981-11-12

    40 Ar/ 39 Ar age spectra on anorthoclase phenocrysts from three pumice clasts in the KBS Tuff yield nearly ideal flat patterns, providing good evidence that the samples have remained undisturbed since crystallization. The ages are concordant at 1.88±0.02 Myr, and confirm that the KBS Tuff, a key marker bed in the Koobi Fora Formation, northern Kenya, is now very well dated. These results resolve the conflict between earlier 40 Ar/ 39 Ar and conventional K-Ar dating measurements on the KBS Tuff.

  12. The Separation and the Concentration of Minerals from the Zeolitic Volcanic Tuffs. Analytical Composition

    Directory of Open Access Journals (Sweden)

    Dumitru Bulgariu

    2002-04-01

    Full Text Available The separation and concetration of minerals from zeolitic volcanic tuffs represent one of the problems for which the literature not offer, to much practically solutions. The experimental strategy used by as, for the separation minerals from zeolitic volcanic tuffs to comprise the following methods: heavy liquids separation; magnetic separation and electrophoresis separation. For zeolites, silica polymorphs, feldspars and other minerals separated from zeolitic volcanic tuffs, the work eighth conditions and the proper experimental strategy efficiency has been estabilish. The purity for mineral fractions can be separated has been between 95.0 – 99.6 %.

  13. Object linking in repositories

    Science.gov (United States)

    Eichmann, David (Editor); Beck, Jon; Atkins, John; Bailey, Bill

    1992-01-01

    This topic is covered in three sections. The first section explores some of the architectural ramifications of extending the Eichmann/Atkins lattice-based classification scheme to encompass the assets of the full life cycle of software development. A model is considered that provides explicit links between objects in addition to the edges connecting classification vertices in the standard lattice. The second section gives a description of the efforts to implement the repository architecture using a commercially available object-oriented database management system. Some of the features of this implementation are described, and some of the next steps to be taken to produce a working prototype of the repository are pointed out. In the final section, it is argued that design and instantiation of reusable components have competing criteria (design-for-reuse strives for generality, design-with-reuse strives for specificity) and that providing mechanisms for each can be complementary rather than antagonistic. In particular, it is demonstrated how program slicing techniques can be applied to customization of reusable components.

  14. A Natural Analogue for Thermal-Hydrological-Chemical Coupled Processes at the Proposed Nuclear Waste Repository at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Bill Carey; Gordon Keating; Peter C. Lichtner

    1999-01-01

    Dike and sill complexes that intruded tuffaceous host rocks above the water table are suggested as natural analogues for thermal-hydrologic-chemical (THC) processes at the proposed nuclear waste repository at Yucca Mountain, Nevada. Scoping thermal-hydrologic calculations of temperature and saturation profiles surrounding a 30-50 m wide intrusion suggest that boiling conditions could be sustained at distances of tens of meters from the intrusion for several thousand years. This time scale for persistence of boiling is similar to that expected for the Yucca Mountain repository with moderate heat loading. By studying the hydrothermal alteration of the tuff host rocks surrounding the intrusions, insight and relevant data can be obtained that apply directly to the Yucca Mountain repository and can shed light on the extent and type of alteration that should be expected. Such data are needed to bound and constrain model parameters used in THC simulations of the effect of heat produced by the waste on the host rock and to provide a firm foundation for assessing overall repository performance. One example of a possible natural analogue for the repository is the Paiute Ridge intrusive complex located on the northeastern boundary of the Nevada Test Site, Nye County, Nevada. The complex consists of dikes and sills intruded into a partially saturated tuffaceous host rock that has stratigraphic sequences that correlate with those found at Yucca Mountain. The intrusions were emplaced at a depth of several hundred meters below the surface, similar to the depth of the proposed repository. The tuffaceous host rock surrounding the intrusions is hydrothermally altered to varying extents depending on the distance from the intrusions. The Paiute Ridge intrusive complex thus appears to be an ideal natural analogue of THC coupled processes associated with the Yucca Mountain repository. It could provide much needed physical and chemical data for understanding the influence of heat

  15. Modeling of strongly heat-driven flow processes at a potential high-level nuclear waste repository at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Pruess, K.; Tsang, Y.

    1993-01-01

    Two complementary numerical models for analyzing high-level nuclear waste emplacement at Yucca Mountain have been developed. A vertical cross-sectional (X-Z) model permits a realistic representation of hydrogeologic features, such as alternating tilting layers of welded and non-welded tuffs. fault zones, and surface topography. An alternative radially symmetric (R-Z) model is more limited in its ability to describe the hydrogeology of the site, but is better suited to model heat transfer in the host rock. Our models include a comprehensive description of multiphase fluid and heat flow processes, including strong enhancements of vapor diffusion from pore-level phase change effects. The neighborhood of the repository is found to partially dry out from the waste heat. A condensation halo of large liquid saturation forms around the drying zone, from which liquid flows downward at large rates. System response to infiltration from the surface and to ventilation of mined openings is evaluated. The impact of the various flow processes on the waste isolation capabilities of the site is discussed

  16. Modeling of strongly heat-driven flow processes at a potential high-level nuclear waste repository at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Pruess, K.; Tsang, Y.

    1993-01-01

    Two complementary numerical models for analyzing high-level nuclear waste emplacement at Yucca Mountain have been developed. A vertical cross-sectional (X-Z) model permits a realistic representation of hydrogeologic features, such as alternating tilting layers of welded and non-welded tuffs, fault zones, and surface topography. An alternative radially symmetric (R-Z) model is more limited in its ability to describe the hydrogeology of the site, but is better suited to model heat transfer in the host rock. Our models include a comprehensive description of multiphase fluid and heat flow processes, including strong enhancements of vapor diffusion from pore-level phase change effects. The neighborhood of the repository is found to partially dry out from the waste heat. A condensation halo of large liquid saturation forms around the drying zone, from which liquid flows downward at large rates. System response to infiltration from the surface and to ventilation of mined openings is evaluated. The impact of the various flow processes on the waste isolation capabilities of the site is discussed

  17. Monitored retrievable storage (MRS) facility and salt repository integration: Engineering study report

    International Nuclear Information System (INIS)

    1987-07-01

    This MRS Facility and Salt Repository Integration Study evaluates the impacts of an integrated MRS/Salt Repository Waste Management System on the Salt Repository Surface facilities' design, operations, cost, and schedule. Eight separate cases were studied ranging from a two phase repository design with no MRS facility to a design in which the repository only received package waste from the MRS facility for emplacement. The addition of the MRS facility to the Waste Management System significantly reduced the capital cost of the salt repository. All but one of the cases studied were capable of meeting the waste acceptance data. The reduction in the size and complexity of the Salt Repository waste handling building with the integration of the MRS facility reduces the design and operating staff requirements. 7 refs., 35 figs., 43 tabs

  18. Safety analysis in subsurface repositories

    International Nuclear Information System (INIS)

    1985-06-01

    The development of mathematical models to represent the repository-geosphere-biosphere system, and the development of a structure for data acquisition, processing, and use to analyse the safety of subsurface repositories, are presented. To study the behavior of radionuclides in geosphere a laboratory to determine the hydrodynamic dispersion coefficient was constructed. (M.C.K.) [pt

  19. Management of digital preservation repositories

    Directory of Open Access Journals (Sweden)

    Miguel Ángel Márdero Arellano

    2016-09-01

    Full Text Available The object of this work are the international experiences of implementation of digital preservation practices in repositories. It based on bibliographical survey about the beginning of digital preservation practices in digital repositories, identifying important aspects of how to manage the practices of digital preservation on repositories. Most repositories analyzed showed a double function of access and preservation, but few could be considered to be "dark archives" used only for preservation matters. The application of digital preservation standards showed that large institutions possessed detailed definitions of what stored materials could be filed and used. Repositories managers had some kind of operating budget to carry on preservation activities. Most repositories cited in the bibliography used a combination of commercial tools and free software. As a conclusion, the records analyzed reinforce the need today of the application of digital preservation strategies using the OAIS Reference Model and official audit certification actions  on the design of digital preservation repositories, to keep the integration flexibility of  functions and services that go beyond the repository.

  20. Accelerator Physics Code Web Repository

    CERN Document Server

    Zimmermann, Frank; Bellodi, G; Benedetto, E; Dorda, U; Giovannozzi, Massimo; Papaphilippou, Y; Pieloni, T; Ruggiero, F; Rumolo, G; Schmidt, F; Todesco, E; Zotter, Bruno W; Payet, J; Bartolini, R; Farvacque, L; Sen, T; Chin, Y H; Ohmi, K; Oide, K; Furman, M; Qiang, J; Sabbi, G L; Seidl, P A; Vay, J L; Friedman, A; Grote, D P; Cousineau, S M; Danilov, V; Holmes, J A; Shishlo, A; Kim, E S; Cai, Y; Pivi, M; Kaltchev, D I; Abell, D T; Katsouleas, Thomas C; Boine-Frankenheim, O; Franchetti, G; Hofmann, I; Machida, S; Wei, J

    2006-01-01

    In the framework of the CARE HHH European Network, we have developed a web-based dynamic acceleratorphysics code repository. We describe the design, structure and contents of this repository, illustrate its usage, and discuss our future plans, with emphasis on code benchmarking.

  1. DECOVALEX-THMC Project. Task A. Influence of near field coupled THM phenomena on the performance of a spent fuel repository. Report of Task A1: Preliminary scoping calculations

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Son (ed.) [Canadian Nuclear Safety Commission (Canada); Lanru Jing (ed.) [Royal Institute of Technology, Stockholm (Sweden); Boergesson, Lennart [Clay Technology AB, Lund (Sweden); Chijimatzu, Masakazu [Hazama Corporation (Japan); Jussila, Petri [Helsinki Univ. of Technology, Helsinki (Finland); Rutqvist, Jonny [Lawrence Berkeley National Laboratory CA (United States)

    2007-02-15

    The DECOVALEX-THMC project is an ongoing international co-operative project that was stared in 2004 to support the development of mathematical models of coupled Thermal (T), Hydrological (H), Mechanical (M) and Chemical (C) processes in geological media for siting potential nuclear fuel waste repositories. The general objective is to characterise and evaluate the coupled THMC processes in the near field and far field of a geological repository and to assess their impact on performance assessment: - during the three phases of repository development: excavation phase, operation phase and post-closure phase; - for three different rocks types: crystalline, argillaceous and tuff; - with specific focus on the issues of: Excavation Damaged Zone (EDZ), permanent property changes of rock masses, and glaciation and permafrost phenomena. The project involves a large number of research teams supported by radioactive waste management agencies or governmental regulatory bodies in Canada, China, Finland, France, Germany, Japan, Sweden and USA, who conducted advanced studies and numerical modelling of coupled THMC processes under five tasks. This report presents the definition of the first phase, Task A-1, of the Task A of the project. The task is a working example of how interaction between THMC modelling and SA analysis could be performed. Starting with the technical definition of the Task A, the report presents the results of preliminary THM calculations with a purpose of an initial appreciation of the phenomena and material properties that must be better understood in subsequent phases. Many simplifications and assumptions were introduced and the results should be considered under these assumptions. Based on the evaluation of the multiple teams' results, a few points of concern were identified that may guide the successive phases of Task A studies: 1. The predicted maximum total stress in the MX-80 bentonite could slightly exceed the 15 MPa design pressure for the

  2. Fission-track dating of pumice from the KBS Tuff, East Rudolf, Kenya

    Science.gov (United States)

    Hurford, A.J.; Gleadow, A.J.W.; Naeser, C.W.

    1976-01-01

    Fission-track dating of zircon separated from two pumice samples from the KBS Tuff in the Koobi Fora Formation, in Area 131, East Rudolf, Kenya, gives an age of 2.44??0.08 Myr for the eruption of the pumice. This result is compatible with the previously published K-Ar and 40Ar/ 39Ar age spectrum estimate of 2.61??0.26 Myr for the KBS Tuff in Area 105, but differs from the more recently published K-Ar date of 1.82??0.04 Myr for the KBS Tuff in Area 131. This study does not support the suggestion that pumice cobbles of different ages occur in the KBS Tuff. ?? 1976 Nature Publishing Group.

  3. Influence analysis of Github repositories.

    Science.gov (United States)

    Hu, Yan; Zhang, Jun; Bai, Xiaomei; Yu, Shuo; Yang, Zhuo

    2016-01-01

    With the support of cloud computing techniques, social coding platforms have changed the style of software development. Github is now the most popular social coding platform and project hosting service. Software developers of various levels keep entering Github, and use Github to save their public and private software projects. The large amounts of software developers and software repositories on Github are posing new challenges to the world of software engineering. This paper tries to tackle one of the important problems: analyzing the importance and influence of Github repositories. We proposed a HITS based influence analysis on graphs that represent the star relationship between Github users and repositories. A weighted version of HITS is applied to the overall star graph, and generates a different set of top influential repositories other than the results from standard version of HITS algorithm. We also conduct the influential analysis on per-month star graph, and study the monthly influence ranking of top repositories.

  4. Technology overview of mined repositories

    International Nuclear Information System (INIS)

    Gimera, R.; Thirumalai, K.

    1982-01-01

    Mined repositories present an environmentally viable option for permanent disposal of nuclear waste. This paper reviews the state-of-the-art mining technologies and identifies technological issues and developments necessary to mine a repository in basalt. The thermal loading, isolation, and retrieval requirements of a repository present unique technological challenges unknown to conventional mining practice. The technology issues and developments required in the areas of excavation, roof and ground support, equipment development, instrumentation development, and sealing are presented. Performance assessment methods must be developed to evaluate the adequacies of technologies developed to design, construct, operate, and decommission a repository. A stepwise test-and-development approach is used in the Basalt Waste Isolation Project to develop cost-effective technologies for a repository

  5. Computational Materials Repository

    DEFF Research Database (Denmark)

    Landis, David

    database have to be redesigned for every new project. Sharing intermediate data with collaborators can be cumbersome and when publishing on the Internet specially tailored infrastructure has to be set up. Due to the diverse and changing landscape of electronic structure codes and methods there is no unique......, different abstraction levels and enables users to analyze their own results, and allows to share data with collaborators. The approach of the Computational Materials Repository (CMR) is to convert data to an internal format that maintains the original variable names without insisting on any semantics....... Imported data can be implicitly grouped by user criteria and therefore maintain their natural connection in the database as well. Automatic data analysis is enabled through agents that analyze and group data based on predefined rules. Small projects can be handled without the need of database software...

  6. The INDEPTH Data Repository

    Science.gov (United States)

    Juvekar, Sanjay; Bhattacharjee, Tathagata; Bangha, Martin; Patharia, Nidhi; Tei, Titus; Gilbert, Brendan; Sankoh, Osman

    2015-01-01

    The International Network for the Demographic Evaluation of Populations and Their Health (INDEPTH) is a global network of research centers that conduct longitudinal health and demographic evaluation of populations in low- and middle-income countries (LMICs) currently in 52 health and demographic surveillance system (HDSS) field sites situated in sub-Saharan Africa (14 countries), Asia (India, Bangladesh, Thailand, Vietnam, and Indonesia), and Oceania (Papua New Guinea). Through this network of HDSS field sites, INDEPTH is capable of producing reliable longitudinal data about the lives of people in the research communities as well as how development policies and programs affect those lives. The aim of the INDEPTH Data Repository is to enable INDEPTH member centers and associated researchers to contribute and share fully documented, high-quality datasets with the scientific community and health policy makers. PMID:26297754

  7. Implementation status of NWPA requirements and relevant activities of the repository projects

    International Nuclear Information System (INIS)

    Hewitt, W.M.; Friedman, P.L.

    1984-01-01

    To date, the Department of Energy (DOE) has focussed considerable effort on implementing the provisions of the Nuclear Waste Policy Act of 1982 (NWPA) for screening, nominating, and recommending sites for geologic repositories and for preparation of documents reflecting DOE's repository strategy. In February 1983, nine potentially acceptable sites in three different geologic media (salt, tuff, basalt) were identified. DOE has prepared Siting Guidelines and submitted them to the Nuclear Regulatory Commission for concurrence. Preparation of draft environmental assessments (EAs) based on the guidelines to support site nominations is underway; the EAs are expected to be issued for public comment in August 1984. The final EAs which are scheduled to be issued in December 1984 will provide the basis for the recommendation of three sites to the President for site characterization by January 1985, the date mandated by the NWPA. In April 1984, the draft Mission Plan was issued for public comment. The plan discusses repository program objectives and overall strategy and presents the detailed information required by Section 301 of the NWPA. The DOE is also developing a Project Decision Schedule which will reflect the Mission Plan schedules as well as provide a sequence of deadlines for all Federal agency actions required by the NWPA and identify the critical path for repository development

  8. A performance assessment review tool for the proposed radioactive waste repository at Yucca Mountain, Nevada, USA

    International Nuclear Information System (INIS)

    Mohanty, Sitakanta; Codell, Richard

    2000-01-01

    The U.S. Nuclear Regulatory Commission (NRC), with the assistance of the Center for Nuclear Waste Regulatory Analyses, has developed a Total-system Performance Assessment (TPA) Code to assist in evaluating the performance of the Yucca Mountain (YM) High-Level Waste Repository in Nevada, proposed by the U.S. Department of Energy (DOE). The proposed YM repository would be built in a thick sequence of partially saturated volcanic tuff above the water table. Among the unique challenges of this environment are (1) the transport of radionuclides would take place partially through highly heterogeneous unsaturated rock; (2) the waste packages (WPs) would be generally exposed to oxidizing conditions, and (3) water either infiltrating from the surface or recirculating because of decay heat may drip onto the WPs. Tools such as the TPA code and embedded techniques for evaluating YM performance are aimed at (1) determining the parameters and key parts of the repository system that have the most influence on repository performance; (2) performing alternative conceptual models studies, especially with bounding models; (3) estimating the relative importance of the physical phenomena that lead to human exposure to radionuclides; and (4) improving NRC staff capabilities in performance assessment and associated license application reviews. This paper presents an overview of the NRC conceptual framework, approach to conducting system-level sensitivity analyses for determining influential parameters, and alternative conceptual model studies to investigate the effect of model uncertainties. (author)

  9. Laboratory investigation of constitutive property up-scaling in volcanic tuffs

    International Nuclear Information System (INIS)

    Tidwell, V.C.

    1996-08-01

    One of the critical issues facing the Yucca Mountain site characterization and performance assessment programs is the manner in which property up-scaling is addressed. Property up-scaling becomes an issue whenever heterogeneous media properties are measured at one scale but applied at another. A research program has been established to challenge current understanding of property up-scaling with the aim of developing and testing improved models that describe up-scaling behavior in a quantitative manner. Up-scaling of constitutive rock properties is investigated through physical experimentation involving the collection of suites of gas-permeability data measured over a range of discrete scales. To date, up-scaling studies have been performed on a series of tuff and sandstone (used as experimental controls) blocks. Samples include a welded, anisotropic tuff (Tiva Canyon Member of the Paintbrush Tuff, upper cliff microstratigraphic unit), and a moderately welded tuff (Tiva Canyon Member of the Paintbrush Tuff, Caprock microstratigraphic unit). A massive fluvial sandstone (Berea Sandstone) was also investigated as a means of evaluating the experimental program and to provide a point of comparison for the tuff data. Because unsaturated flow is of prime interest to the Yucca Mountain Program, scoping studies aimed at investigating the up-scaling of hydraulic properties under various saturated conditions were performed to compliment these studies of intrinsic permeability. These studies focused on matrix sorptivity, a constitutive property quantifying the capillarity of a porous medium. 113 refs

  10. Chemistry and mineralogy of some Plio-Pleistocene tuffs from the Shungura Formation, southwest Ethiopia

    Science.gov (United States)

    Martz, A. M.; Brown, F. H.

    1981-09-01

    The Shungura Formation of southwestern Ethiopia has yielded many tens of thousands of vertebrate fossils including hominids and microvertebrates, and in addition has also yielded fossil wood, pollen, and invertebrates. Widespread tuffs have made subdivision and detailed mapping of the formation possible, have provided material for potassium-argon dating, and have allowed direct lithostratigraphic correlation with the Koobi Fora Formation in northern Kenya. The basis for correlation between the two formations is the distinctive chemistry of the tuffs, but systematic chemical variation within some tuffs invalidates some statistical correlation techniques. Here chemical analysis of glass separates and minerals from tuffs of the Shungura and Usno Formations are presented which may allow further ties to be established when data become available on other tuffs of the Koobi Fora Formation. The tuffs consist primarily of glass, but also contain phenocrysts of anorthoclase, hedenbergitic pyroxene, sodic amphibole, ilmenite, titanomagnetite, chevkinite, quartz, zircon, and rarely orthopyroxene and plagioclase. The glasses show evidence of alkali loss during hydration, and are not now peralkaline, although it is likely that they were initially. The source volcanoes were most likely situated within the Ethiopian rift valley, or on its margins.

  11. Laboratory investigation of constitutive property up-scaling in volcanic tuffs

    Energy Technology Data Exchange (ETDEWEB)

    Tidwell, V.C. [Sandia National Labs., Albuquerque, NM (United States). Geohydrology Dept.

    1996-08-01

    One of the critical issues facing the Yucca Mountain site characterization and performance assessment programs is the manner in which property up-scaling is addressed. Property up-scaling becomes an issue whenever heterogeneous media properties are measured at one scale but applied at another. A research program has been established to challenge current understanding of property up-scaling with the aim of developing and testing improved models that describe up-scaling behavior in a quantitative manner. Up-scaling of constitutive rock properties is investigated through physical experimentation involving the collection of suites of gas-permeability data measured over a range of discrete scales. To date, up-scaling studies have been performed on a series of tuff and sandstone (used as experimental controls) blocks. Samples include a welded, anisotropic tuff (Tiva Canyon Member of the Paintbrush Tuff, upper cliff microstratigraphic unit), and a moderately welded tuff (Tiva Canyon Member of the Paintbrush Tuff, Caprock microstratigraphic unit). A massive fluvial sandstone (Berea Sandstone) was also investigated as a means of evaluating the experimental program and to provide a point of comparison for the tuff data. Because unsaturated flow is of prime interest to the Yucca Mountain Program, scoping studies aimed at investigating the up-scaling of hydraulic properties under various saturated conditions were performed to compliment these studies of intrinsic permeability. These studies focused on matrix sorptivity, a constitutive property quantifying the capillarity of a porous medium. 113 refs.

  12. Confort 15 model of conduit dynamics: applications to Pantelleria Green Tuff and Etna 122 BC eruptions

    Science.gov (United States)

    Campagnola, S.; Romano, C.; Mastin, L. G.; Vona, A.

    2016-06-01

    Numerical simulations are useful tools to illustrate how flow parameters and physical processes may affect eruption dynamics of volcanoes. In this paper, we present an updated version of the Conflow model, an open-source numerical model for flow in eruptive conduits during steady-state pyroclastic eruptions (Mastin and Ghiorso in A numerical program for steady-state flow of magma-gas mixtures through vertical eruptive conduits. U.S. Geological Survey Open File Report 00-209, 2000). In the modified version, called Confort 15, the rheological constraints are improved, incorporating the most recent constitutive equations of both the liquid viscosity and crystal-bearing rheology. This allows all natural magma compositions, including the peralkaline melts excluded in the original version, to be investigated. The crystal-bearing rheology is improved by computing the effect of strain rate and crystal shape on the rheology of natural magmatic suspensions and expanding the crystal content range in which rheology can be modeled compared to the original version ( Conflow is applicable to magmatic mixtures with up to 30 vol% crystal content). Moreover, volcanological studies of the juvenile products (crystal and vesicle size distribution) of the investigated eruption are directly incorporated into the modeling procedure. Vesicle number densities derived from textural analyses are used to calculate, through Toramaru equations, maximum decompression rates experienced during ascent. Finally, both degassing under equilibrium and disequilibrium conditions are considered. This allows considerations on the effect of different fragmentation criteria on the conduit flow analyses, the maximum volume fraction criterion ("porosity criterion"), the brittle fragmentation criterion and the overpressure fragmentation criterion. Simulations of the pantelleritic and trachytic phases of the Green Tuff (Pantelleria) and of the Plinian Etna 122 BC eruptions are performed to test the upgrades in

  13. Surface complexation modeling of americium sorption onto volcanic tuff.

    Science.gov (United States)

    Ding, M; Kelkar, S; Meijer, A

    2014-10-01

    Results of a surface complexation model (SCM) for americium sorption on volcanic rocks (devitrified and zeolitic tuff) are presented. The model was developed using PHREEQC and based on laboratory data for americium sorption on quartz. Available data for sorption of americium on quartz as a function of pH in dilute groundwater can be modeled with two surface reactions involving an americium sulfate and an americium carbonate complex. It was assumed in applying the model to volcanic rocks from Yucca Mountain, that the surface properties of volcanic rocks can be represented by a quartz surface. Using groundwaters compositionally representative of Yucca Mountain, americium sorption distribution coefficient (Kd, L/Kg) values were calculated as function of pH. These Kd values are close to the experimentally determined Kd values for americium sorption on volcanic rocks, decreasing with increasing pH in the pH range from 7 to 9. The surface complexation constants, derived in this study, allow prediction of sorption of americium in a natural complex system, taking into account the inherent uncertainty associated with geochemical conditions that occur along transport pathways. Published by Elsevier Ltd.

  14. Geophysical tomography for imaging water movement in welded tuff

    International Nuclear Information System (INIS)

    Daily, W.D.; Ramirez, A.L.

    1986-09-01

    Alterant tomography has been evaluated for its ability to delineate in-situ water flow paths in a fractured welded-tuff rock mass. The evaluation involved a field experiment in which tomographs of electromagnetic attenuation factor (or attenuation rate) at 300 MHz were made before, during, and after the introduction to the rock of two different water-based tracers: a plain water and dye solution, and salt water and dye. Alterant tomographs were constructed by subtracting, cell by cell, the attenuation factors derived from measurements before each tracer was added to the rock mass from the attenuation factors derived after each tracer was added. The alterant tomographs were compared with other evidence of water movement in the rock: borescope logs of fractures, and post experiment cores used to locate the dye tracer on the fractured surfaces. These comparisons indicate that alterant tomography is suitable for mapping water flow through fractures and that it may be useful in inferring which of the fractures are hydrologically connected in the image plane. The technique appears to be sensitive enough to delineate flow through a single fracture and to define fractures with a spatial resolution of about 10 cm on an imaging scale of a few meters. 9 refs., 3 figs

  15. Influence of Lithophysal Geometry on the Uniaxial Compression of Tuff-Like Rock

    International Nuclear Information System (INIS)

    Rigby, Douglas B.

    2007-01-01

    A large portion of the rock of the high-level nuclear waste repository at Yucca Mountain contains lithophysae or voids. These voids have a significant detrimental effect on the engineering properties of the rock mass and its performance. The lithophysae were formed at the time of volcanic deposition by pockets of gas trapped within the compressing and cooling pyroclastic flow material. Lithophysae vary by size, shape, and spatial frequency of occurrence. Due to the difficulties of testing actual lithophysal rock, the current mechanical property data set is limited and the numerical models of lithophysal rock are not well validated. The purpose of this task was to experimentally quantify the effect of void geometry in the mechanical compression of cubes of analog lithophysal-like rock. In this research the mechanical properties of the analog rock were systematically studied by examining various patterns of voids based on variables consisting of hole shape, size, and geometrical distribution. Each specified hole pattern was cast into 6 by 6 by 6-in. Hydro-StoneTB(reg s ign) specimens (produced in triplicate) and then tested under uniaxial compression. Solid Hydro-StoneTB(reg s ign) specimens exhibited similar mechanical properties to those estimated for rock mass solid specimens of Topopah Spring tuff. The results indicated that the compressive strength and Young's Modulus values decrease with increasing specimen void porosity. The modulus and strength with void porosity relationships are essentially linear over the 5 to 20 percent void porosity range. When zero void porosity (solid specimen) results are added, exponential functions do not provide a good fit to the data due to a significant sensitivity of strength and modulus to the presence of macro-sized voids. From solid specimens there is roughly a 60 percent drop in strength with about 7 percent void porosity, increasing to an 80 percent drop at about 20 percent void porosity. The percent change in modulus from

  16. Studies on an advanced repository system with enhanced engineered barriers (a framework)

    International Nuclear Information System (INIS)

    Fujiwara, A.; Tashiro, S.; Ikari, S.; Suzuki, A.

    1993-01-01

    In order to propose advanced designs of repositories with enhanced engineered barriers of relatively high radioactive wastes such as burnable poisons, channel boxes, control rods and highly irradiated metals, studies started in 1987 and completed the first phase in 1992. This paper presents the framework and brief results of the first phase. The studies set preliminary design concepts of the repositories with various combinations with engineered barriers and natural barriers for different models and locations such as a silo type in shallow land or a tunnel type in intermediate depth. Through the designs, four component technics were picked up and studied for (1) construction of the components in repository; (2) performance evaluation to realize repository design; (3) improvement of circumstances inside or around repository; and (4) surveillance of repository performance to realize the repository designs. Finally, some repository systems were provided using obtained results, and then the applicability and the economy were evaluated. The studies will continue to the second phase focusing on the long-term performance of the repositories

  17. Representation of an open repository in groundwater flow models

    International Nuclear Information System (INIS)

    Painter, Scott; Sun, Alexander

    2005-08-01

    The effect of repository tunnels on groundwater flow has been identified as a potential issue for the nuclear waste repository being considered by SKB for a fractured granite formation in Sweden. In particular, the following pre-closure and post-closure processes have been identified as being important: inflows into open tunnels as functions of estimated grouting efficiencies, drawdown of the water table in the vicinity of the repository, upcoming of saline water, 'turnover' of surface water in the upper bedrock, and resaturation of backfilled tunnels following repository closure. The representation of repository tunnels within groundwater models is addressed in this report. The primary focus is on far-field flow that is modeled with a continuum porous medium approximation. Of particular interest are the consequences of the tunnel representation on the transient response of the groundwater system to repository operations and repository closure, as well as modeling issues such as how the water-table free surface and the coupling to near-surface hydrogeology should be handled. The overall objectives are to understand the consequences of current representations and to identify appropriate approximations for representing open tunnels in future groundwater modeling studies. The following conclusions can be drawn from the results of the simulations: 1. Two-phase flow may be induced in the vicinity of repository tunnels during repository pre-closure operations, but the formation of a two-phase flow region will not significantly affect far-field flow or inflows into tunnels. 2. The water table will be drawn down to the repository horizon and tunnel inflows will reach a steady-state value within about 5 years. 3. Steady-state inflows at the repository edge are estimated to be about 250 m 3 /year per meter of tunnel. Inflows will be greater during the transient de-watering period and less for tunnel locations closer to the repository center. 4. Significant amounts of water

  18. Representation of an open repository in groundwater flow models

    Energy Technology Data Exchange (ETDEWEB)

    Painter, Scott; Sun, Alexander [Southwest Research Inst., San Antonio, TX (United States). Center for Nuclear Waste Regulatory Analyses

    2005-08-01

    The effect of repository tunnels on groundwater flow has been identified as a potential issue for the nuclear waste repository being considered by SKB for a fractured granite formation in Sweden. In particular, the following pre-closure and post-closure processes have been identified as being important: inflows into open tunnels as functions of estimated grouting efficiencies, drawdown of the water table in the vicinity of the repository, upcoming of saline water, 'turnover' of surface water in the upper bedrock, and resaturation of backfilled tunnels following repository closure. The representation of repository tunnels within groundwater models is addressed in this report. The primary focus is on far-field flow that is modeled with a continuum porous medium approximation. Of particular interest are the consequences of the tunnel representation on the transient response of the groundwater system to repository operations and repository closure, as well as modeling issues such as how the water-table free surface and the coupling to near-surface hydrogeology should be handled. The overall objectives are to understand the consequences of current representations and to identify appropriate approximations for representing open tunnels in future groundwater modeling studies. The following conclusions can be drawn from the results of the simulations: 1. Two-phase flow may be induced in the vicinity of repository tunnels during repository pre-closure operations, but the formation of a two-phase flow region will not significantly affect far-field flow or inflows into tunnels. 2. The water table will be drawn down to the repository horizon and tunnel inflows will reach a steady-state value within about 5 years. 3. Steady-state inflows at the repository edge are estimated to be about 250 m{sup 3}/year per meter of tunnel. Inflows will be greater during the transient de-watering period and less for tunnel locations closer to the repository center. 4. Significant

  19. Biospecimen repositories and cytopathology.

    Science.gov (United States)

    Krishnamurthy, Savitri

    2015-03-01

    Biospecimen repositories are important for the advancement of biomedical research. Literature on the potential for biobanking of fine-needle aspiration, gynecologic, and nongynecologic cytology specimens is very limited. The potential for biobanking of these specimens as valuable additional resources to surgically excised tissues appears to be excellent. The cervicovaginal specimens that can be used for biobanking include Papanicolaou-stained monolayer preparations and residual material from liquid-based cytology preparations. Different types of specimen preparations of fine-needle aspiration and nongynecologic specimens, including Papanicolaou-stained and Diff-Quik-stained smears, cell blocks. and dedicated passes/residual material from fine-needle aspiration stored frozen in a variety of solutions, can be used for biobanking. Because of several gaps in knowledge regarding the standard of operative procedures for the procurement, storage, and quality assessment of cytology specimens, further studies as well as national conferences and workshops are needed not only to create awareness but also to facilitate the use of cytopathology specimens for biobanking. © 2014 American Cancer Society.

  20. Privacy Impact Assessment (PIA) Repository

    Data.gov (United States)

    Department of Veterans Affairs — This repository contains Privacy Impact Assessments (PIA) that have been vetted/approved. Section 208 of the Electronic Government Act of 2002 (E-Gov Act) requires...

  1. VHA Data Sharing Agreement Repository

    Data.gov (United States)

    Department of Veterans Affairs — The VHA Data Sharing Agreement Repository serves as a centralized location to collect and report on agreements that share VHA data with entities outside of VA. It...

  2. NIH Common Data Elements Repository

    Data.gov (United States)

    U.S. Department of Health & Human Services — The NIH Common Data Elements (CDE) Repository has been designed to provide access to structured human and machine-readable definitions of data elements that have...

  3. The role of fracture coatings on water imbibition into unsaturated tuff from Yucca Mountain

    International Nuclear Information System (INIS)

    Chekuri, V.S.; Tyler, S.W.; Fordham, J.W.

    1995-11-01

    Studies dealing with fracture flow at Yucca Mountain have generally assumed that any water flowing down in a fracture will be absorbed by the porous matrix. However, a thin lining of low permeability material on the fracture walls may significantly impede imbibition into the matrix of unsaturated tuff. In this research, imbibition was measured across the fracture surfaces in the laboratory. Samples were collected from surface outcrops of Tiva Canyon and Topopah Spring members of the Paintbrush tuff near Yucca Mountain. Sorptivity, a convenient measure of imbibition, was used to investigate the changes in hydraulic properties as a result of fracture coatings. Results from experimental analysis of Topopah Spring tuff showed decreased sorptivity across coated fracture surfaces. Statistically, the coatings on the Tiva Canyon samples do not significantly affect sorptivity. Scanning Electron Microscope analysis shows that coatings on the s grit Tiva Canyon samples are made up of iron, aluminum and to some extent magnesium. Coating material on the Topopah Spring samples is made up of calcium, magnesium, aluminum and iron. Coating significantly reduces the sorptivity for the Topopah Spring tuff. Numerical results are presented to show the effect of fracture coatings on water infiltration down a vertical fracture in simulated tuff. For the Topopah Spring tuff, the wetting front in the coated fracture travels deeper in the fracture and less into the matrix compared to the wetting front in the uncoated fracture. For the Tiva Canyon tuff, the wetting front in the uncoated fracture travels deeper in the fracture and less into the matrix as compared to the wetting front in the coated fracture

  4. New data on the Volcanic Tuff from Petrestii de Jos (Cluj District

    Directory of Open Access Journals (Sweden)

    Bedelean Horea

    2001-04-01

    Full Text Available The present study was carried out on the cineritic interlayers from Petreştii de Jos (closed quarry from Indolului Valley, in order to present their detailed mineralogical-petrographical features. Previous work already noticed the similarity of this tuff level with Dej Tuff Complex in other areas. The studied outcrop consists of a compact volcanic tuff interlayered with marls and tuffaceous clays. The analytical investigations: chemical analyses, X-ray diffraction, IR spectroscopy and electron microscopy reveal the nature of the diagenetic transformations dominated by zeolitization. Besides clinoptilolite, which is the typical zeolite for Dej Tuff from the Transylvanian Depression, our investigation evidenced also the presence of phillipsite. The process was stepwise: during the primary, syngenetic stage K-clinoptilolite formed, while during the late epigenetic stage Ca-phillipsite crystallized; on behalf of the latter one, Ca-clinoptilolite was also generated. It is worth to mention that the highest amounts of zeolites are to be found in the basal horizon, while this amount decreases in the interlayers associated with the marly-clayey levels. From genetic point of view, the lower horizon in the outcrop represents a primary fall-out tuff. The thin interlayers within the upper horizons are resedimented tuffs. The tuff from Petreştii de Jos represents a cheap raw material located in the neighborhood of the industrial area of Turda town. For using it, only a more detailed research and the removal of the vegetal and soil layer on the top would be necessary.

  5. Nuclear dynamics consequence analysis of SNF disposed in volcanic tuff

    International Nuclear Information System (INIS)

    Sanchez, L.C.; Cochrane, K.; Rath, J.S.; Taylor, L.L.

    1998-05-01

    This paper describes criticality analyses for spent nuclear fuels in a geologic repository. The analyses investigated criticality potential, criticality excursion consequences, and the probability frequency for nuclear criticality. Key findings include: expected number of fissions per excursion range from 10 17 to 10 20 , repeated rate of criticalities range from 3 to 30 per year, and the probability frequency for criticality initiators (based on rough-order-of-magnitude calculations) is 7x10 -7 . Overall results indicate that criticality consequences are a minor contribution to the biological hazards caused by the disposal of spent nuclear material

  6. 40 CFR 124.33 - Information repository.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Information repository. 124.33 Section... FOR DECISIONMAKING Specific Procedures Applicable to RCRA Permits § 124.33 Information repository. (a... basis, for an information repository. When assessing the need for an information repository, the...

  7. Tools for Managing Repository Objects

    OpenAIRE

    Banker, Rajiv D.; Isakowitz, Tomas; Kauffman, Robert J.; Kumar, Rachna; Zweig, Dani

    1993-01-01

    working Paper Series: STERN IS-93-46 The past few years have seen the introduction of repository-based computer aided software engineering (CASE) tools which may finally enable us to develop software which is reliable and affordable. With the new tools come new challenges for management: Repository-based CASE changes software development to such an extent that traditional approaches to estimation, performance, and productivity assessment may no longer suffice - if they ever...

  8. Conceptual design of repository facilities

    International Nuclear Information System (INIS)

    Beale, H.; Engelmann, H.J.; Souquet, G.; Mayence, M.; Hamstra, J.

    1980-01-01

    As part of the European Economic Communities programme of research into underground disposal of radioactive wastes repository design studies have been carried out for application in salt deposits, argillaceous formations and crystalline rocks. In this paper the design aspects of repositories are reviewed and conceptual designs are presented in relation to the geological formations under consideration. Emphasis has been placed on the disposal of vitrified high level radioactive wastes although consideration has been given to other categories of radioactive waste

  9. IAEA safeguards for geological repositories

    International Nuclear Information System (INIS)

    Moran, B.W.

    2005-01-01

    In September. 1988, the IAEA held its first formal meeting on the safeguards requirements for the final disposal of spent fuel and nuclear material-bearing waste. The consensus recommendation of the 43 participants from 18 countries at this Advisory Group Meeting was that safeguards should not terminate of spent fuel even after emplacement in, and closure of, a geologic repository.' As a result of this recommendation, the IAEA initiated a series of consultants' meetings and the SAGOR Programme (Programme for the Development of Safeguards for the Final Disposal of Spent Fuel in Geologic Repositories) to develop an approach that would permit IAEA safeguards to verify the non-diversion of spent fuel from a geologic repository. At the end of this process, in December 1997, a second Advisory Group Meeting, endorsed the generic safeguards approach developed by the SAGOR Programme. Using the SAGOR Programme results and consultants' meeting recommendations, the IAEA Department of Safeguards issued a safeguards policy paper stating the requirements for IAEA safeguards at geologic repositories. Following approval of the safeguards policy and the generic safeguards approach, the Geologic Repository Safeguards Experts Group was established to make recommendations on implementing the safeguards approach. This experts' group is currently making recommendations to the IAEA regarding the safeguards activities to be conducted with respect to Finland's repository programme. (author)

  10. Reference Design Description for a Geologic Repository

    Energy Technology Data Exchange (ETDEWEB)

    NA

    2000-10-07

    One of the current major national environmental problems is the safe disposal of large quantities of spent nuclear fuel and high-level radioactive waste materials, which are rapidly accumulating throughout the country. These radioactive byproducts are generated as the result of national defense activities and from the generation of electricity by commercial nuclear power plants. At present, spent nuclear fuel is accumulating at over 70 power plant sites distributed throughout 33 states. The safe disposal of these high-level radioactive materials at a central disposal facility is a high national priority. This Reference Design Description explains the current design for a potential geologic repository that may be located at Yucca Mountain in Nevada for the disposal of spent nuclear fuel and high-level radioactive waste materials. This document describes a possible design for the three fundamental parts of a repository: a surface facility, subsurface repository, and waste packaging. It also presents the current conceptual design of the key engineering systems for the final four phases of repository processes: operations, monitoring, closure, and postclosure. In accordance with current law, this design does not include an interim storage option. In addition, this Reference Design Description reviews the expected long-term performance of the potential repository. It describes the natural barrier system which, together with the engineered systems, achieves the repository objectives. This design will protect the public and the environment by allowing the safe disposal of radioactive waste received from government-owned custodial spent fuel sites, high-level radioactive waste sites, and commercial power reactor sites. All design elements meet or exceed applicable regulations governing the disposal of high-level radioactive waste. The design will provide safe disposal of waste materials for at least a 10,000 year period. During this time interval, natural radioactive decay

  11. Reference Design Description for a Geologic Repository

    International Nuclear Information System (INIS)

    2000-01-01

    One of the current major national environmental problems is the safe disposal of large quantities of spent nuclear fuel and high-level radioactive waste materials, which are rapidly accumulating throughout the country. These radioactive byproducts are generated as the result of national defense activities and from the generation of electricity by commercial nuclear power plants. At present, spent nuclear fuel is accumulating at over 70 power plant sites distributed throughout 33 states. The safe disposal of these high-level radioactive materials at a central disposal facility is a high national priority. This Reference Design Description explains the current design for a potential geologic repository that may be located at Yucca Mountain in Nevada for the disposal of spent nuclear fuel and high-level radioactive waste materials. This document describes a possible design for the three fundamental parts of a repository: a surface facility, subsurface repository, and waste packaging. It also presents the current conceptual design of the key engineering systems for the final four phases of repository processes: operations, monitoring, closure, and postclosure. In accordance with current law, this design does not include an interim storage option. In addition, this Reference Design Description reviews the expected long-term performance of the potential repository. It describes the natural barrier system which, together with the engineered systems, achieves the repository objectives. This design will protect the public and the environment by allowing the safe disposal of radioactive waste received from government-owned custodial spent fuel sites, high-level radioactive waste sites, and commercial power reactor sites. All design elements meet or exceed applicable regulations governing the disposal of high-level radioactive waste. The design will provide safe disposal of waste materials for at least a 10,000 year period. During this time interval, natural radioactive decay

  12. Radioactive waste repository of high ecological safety

    International Nuclear Information System (INIS)

    Sobolev, I.; Barinov, A.; Prozorov, L.

    2000-01-01

    With the purpose to construct a radioactive waste repository of high ecological safety and reliable containment, MosNPO 'Radon' specialists have developed an advanced type repository - large diameter well (LBD) one. A project is started for the development of a technology for LDW repository construction and pilot operation of the new repository for 25-30 years. The 2 LDW repositories constructed at the 'Radon' site and the developed monitoring system are described

  13. Demystifying the institutional repository for success

    CERN Document Server

    Buehler, Marianne

    2013-01-01

    Institutional repositories remain key to data storage on campus, fulfilling the academic needs of various stakeholders. Demystifying the Institutional Repository for Success is a practical guide to creating and sustaining an institutional repository through marketing, partnering, and understanding the academic needs of all stakeholders on campus. This title is divided into seven chapters, covering: traditional scholarly communication and open access publishing; the academic shift towards open access; what the successful institutional repository looks like; institutional repository collaboratio

  14. Virtual patient repositories--a comparative analysis.

    Science.gov (United States)

    Küfner, Julia; Kononowicz, Andrzej A; Hege, Inga

    2014-01-01

    Virtual Patients (VPs) are an important component of medical education. One way to reduce the costs for creating VPs is sharing through repositories. We conducted a literature review to identify existing repositories and analyzed the 17 included repositories in regards to the search functions and metadata they provide. Most repositories provided some metadata such as title or description, whereas other data, such as educational objectives, were less frequent. Future research could, in cooperation with the repository provider, investigate user expectations and usage patterns.

  15. Preliminary survey of tuff distribution in Esmeralda, Nye, and Lincoln Counties, Nevada

    International Nuclear Information System (INIS)

    Smith, G.V.; Pink, T.S.; Lawrence, J.R.; Woodward, L.A.; Keil, K.; Lappin, A.R.

    1981-02-01

    This report inventories the surface distribution of silicic tuffs in Nye, Esmeralda, and Lincoln Counties, NV, based on a review of available literature. The inventory was taken to provide a data base in evaluating tuff sites for the disposal of high-level nuclear waste. Silicic ash-flow tuffs that are about 11 to 34 million years (my) old are widespread in these counties. These rocks are locally deformed by right-lateral movement along Walker Lane and the Las Vegas Shear Zone, and left-lateral movement along a zone from near the Nevada Test Site (NTS) to the Utah border, and are commonly offset by steeply dipping normal faults. The normal faults that bound horsts, grabens, and tilted-fault blocks of the Basin-and-Range Province began to form 30 my ago; some are still active. Tuff distribution is discussed on a regional basis. Tuff thicknesses and alterations, structural complexity, and proximity to recent faulting, recent volcanism, and mineral resources are discussed for each area. Although the literature on which it is based is often incomplete and sketchy, this report is intended to serve as a basis for future, more detailed work that includes initial field inspection, detailed field and laboratory studies, and extrapolations to the subsurface

  16. Actinide transport in Topopah Spring Tuff: Pore size, particle size, and diffusion

    International Nuclear Information System (INIS)

    Buchholtz ten Brink, M.; Phinney, D.L.; Smith, D.K.

    1991-04-01

    Diffusive transport rates for aqueous species in a porous medium are a function of sorption, molecular diffusion, and sample tortuosity. With heterogeneous natural samples, an understanding of the effect of multiple transport paths and sorption mechanisms is particularly important since a small amount of radioisotope traveling via a faster-than-anticipated transport path may invalidate the predictions of transport codes which assume average behavior. Static-diffusion experiments using aqueous 238 U tracer in tuff indicated that U transport was faster in regions of greater porosity and that apparent diffusion coefficients depended on the scale (m or μm) over which concentration gradients were measured in Topopah Spring Tuff. If a significant fraction of actinides in high-level waste are released to the environment in forms that do not sorb to the matrix, they may be similarly transported along fast paths in porous regions of the tuff. To test this, aqueous diffusion rates in tuff were measured for 238 U and 239 Pu leached from doped glass. Measured transport rates and patterns were consistent in both systems with a dual-porosity transported moeld. In addition, filtration or channelling of actinides associated with colloidal particles may significantly affect the radionuclide transport rate in Topopah Spring tuff. 9 refs., 7 figs

  17. Analysis of the rock mechanics properties of volcanic tuff units from Yucca Mountain, Nevada Test Site

    International Nuclear Information System (INIS)

    Price, R.H.

    1983-08-01

    Over two hundred fifty mechanical experiments have been run on samples of tuff from Yucca Mountain, Nevada Test Site. Cores from the Topopah Spring, Calico Hills, Bullfrog and Tram tuff units were deformed to collect data for an initial evaluation of mechanical (elastic and strength) properties of the potential horizons for emplacement of commercial nuclear wastes. The experimental conditions ranged in sample saturation from room dry to fully saturated, confining pressure from 0.1 to 20 MPa, pore pressure from 0.1 to 5 MPa, temperature from 23 to 200 0 C, and strain rate from 10 -7 to 10 -2 s -1 . These test data have been analyzed for variations in elastic and strength properties with changes in test conditions, and to study the effects of bulk-rock characteristics on mechanical properties. In addition to the site-specific data on Yucca Mountain tuff, mechanical test results on silicic tuff from Rainier Mesa, Nevada Test Site, are also discussed. These data both overlap and augment the Yucca Mountain tuff data, allowing more definitive conclusions to be reached, as well as providing data at some test conditions not covered by the site-specific tests

  18. Durability of cemented waste in repository and under simulated conditions

    International Nuclear Information System (INIS)

    Dragolici, F.; Nicu, M.; Lungu, L.; Turcanu, C.; Rotarescu, Gh.

    2000-01-01

    simulated disposal conditions for reference samples; - emplacement of reference samples in Baita Bihor Repository for real disposal characterization. All samples were positioned in five locations of Baita-Bihor repository where they will be kept for 1, 3, 5 and 10 years before mechanical and structural characterization. These locations have different humidity values, decreasing from location 1 to 5. The results will be compared with those obtained for the same type of samples kept in laboratory conditions. The mechanical performances of the matrix with cement-mineral additives are not influenced if bentonite or volcanic tuff concentration is is lower than 10%. The very good mechanical behaviour of the samples, drives at the conclusion that the additive cement-mineral mixture could be used in the disposal procedure, with good results, if the future structure characterization would prove the role as engineered barrier. Complexing reagents reduce drastically the mechanical performances. The chemical nature of the complexing agent plays an important role, the damaging effect being more pregnant for tartaric and citric acid than for oxalic acid. In any case there is a maximum limit of concentration which is acceptable from mechanical point of view. The mechanical resistance observed in all samples, after one year disposal, are within the accepted limits for the matrix durability. Thus, disposal conditions has not influence the mechanical properties of the cement matrix after one year disposal. The presented results, showed that bentonite seems to have a positive influence on the quality of the examined matrices . These results are preliminary. The data obtained so far will be completed with those to be obtained after three year disposal. XRD initial investigation of waste samples showed complex changes in the structure and components. To understand the systems, series of different compositions need to be characterized. In the next years the durability of samples kept for times

  19. An approach to improve Romanian geological repository planning

    Energy Technology Data Exchange (ETDEWEB)

    Andrei, Veronica [Romanian Association for Nuclear Energy, Bucharest-Magurele (Romania); Prisecaru, Ilie [University Politehnica of Bucharest, Bucharest (Romania)

    2016-04-15

    International standards recommend typical phases to be included within any national program for the development of a geological repository dedicated to disposal of the high level radioactive wastes generated in countries using nuclear power. However, these are not universally applicable and the content of each of these phases may need to be adapted for each national situation and regulatory and institutional framework. Several national geological repository programs have faced failures in schedules and have revised their programs to consider an adapted phased management approach. The authors have observed that in the case of those countries in the early phases of a geological repository program where boundary conditions have not been fully defined, international recommendations for handling delays/failures in the national program might not immediately help. This paper considers a case study of the influences of the national context risks on the current planning schedule of the Romanian national geological repository. It proposes an optimum solution for an integrated response to any significant adverse impact arising from these risks, enabling sustainable program planning.

  20. An Approach to Improve Romanian Geological Repository Planning

    Directory of Open Access Journals (Sweden)

    Veronica Andrei

    2016-04-01

    Full Text Available International standards recommend typical phases to be included within any national program for the development of a geological repository dedicated to disposal of the high level radioactive wastes generated in countries using nuclear power. However, these are not universally applicable and the content of each of these phases may need to be adapted for each national situation and regulatory and institutional framework. Several national geological repository programs have faced failures in schedules and have revised their programs to consider an adapted phased management approach. The authors have observed that in the case of those countries in the early phases of a geological repository program where boundary conditions have not been fully defined, international recommendations for handling delays/failures in the national program might not immediately help. This paper considers a case study of the influences of the national context risks on the current planning schedule of the Romanian national geological repository. It proposes an optimum solution for an integrated response to any significant adverse impact arising from these risks, enabling sustainable program planning.

  1. Performance assessment of the direct disposal in unsaturated tuff of spent nuclear fuel and high-level waste owned by U.S. Department of Energy. Volume 1: Executive summary

    Energy Technology Data Exchange (ETDEWEB)

    Rechard, R.P. [ed.] [Sandia National Labs., Albuquerque, NM (United States). WIPP Performance Assessment Dept.

    1995-03-01

    This assessment studied the performance of high-level radioactive waste and spent nuclear fuel in a hypothetical repository in unsaturated tuff. The results of this 10-month study are intended to help guide the Office of Environment Management of the US Department of Energy (DOE) on how to prepare its wastes for eventual permanent disposal. The waste forms comprised spent fuel and high-level waste currently stored at the Idaho National Engineering Laboratory (INEL) and the Hanford reservation. About 700 metric tons heavy metal (MTHM) of the waste under study is stored at INEL, including graphite spent nuclear fuel, highly enriched uranium spent fuel, low enriched uranium spent fuel, and calcined high-level waste. About 2,100 MTHM of weapons production fuel, currently stored on the Hanford reservation, was also included. The behavior of the waste was analyzed by waste form and also as a group of waste forms in the hypothetical tuff repository. When the waste forms were studied together, the repository was assumed also to contain about 9,200 MTHM high-level waste in borosilicate glass from three DOE sites. The addition of the borosilicate glass, which has already been proposed as a final waste form, brought the total to about 12,000 MTHM. A source term model was developed to study the wide variety of waste forms, which included radionuclides residing in 10 different matrices and up to 8 nested layers of material that might react with water. The possibility and consequences of critical conditions occurring in or near containers of highly enriched uranium spent nuclear fuel were also studied.

  2. Studies of neo-formed phases occurring during spent nuclear fuel dissolution in geological repository: influence of silicate ions; Etude des phases neoformees lors de la dissolution du combustible nucleaire en condition de stockage geologique: influence des ions silicate

    Energy Technology Data Exchange (ETDEWEB)

    Robit-Pointeau, V

    2005-12-15

    Spent nuclear fuel alteration in deep storage conditions may proceed by local oxidising conditions at the fuel / water interface under influence of alpha irradiation. However, due to the strong redox buffer capacity of the near-field materials (especially the canister and the geological media), most of the near-field environment will remain reducing. Due to the relative high concentration in silica in such system, coffinite USiO{sub 4}.n(H{sub 2}O) may be a relevant phase to consider as it has been suggested from the natural analogues observations (Oklo). The aim of this work was to assess the relevance of coffinitisation of the spent fuel phenomena. The results of the experimental work contest the thermodynamic predictions. Instead of coffinite, a new U(IV)-Si phase has been observed in water simulating storage conditions. The thermodynamic data on coffinite validated by OECD are based on the average concentration of dissolved silica present in natural system containing uraninite and quartz. As the silica concentration in natural groundwaters is more probably controlled by minerals like chalcedony or silica gel, the coffinite present with uraninite in such systems, is probably not in equilibrium even in 2-billion years- old geological sites. Based on the results of this study, coffinitisation of the spent nuclear fuel in deep geological disposal is not anticipated to be a dominant short term process. (author)

  3. An astronomical age for the Bishop Tuff and concordance with radioisotopic dates

    DEFF Research Database (Denmark)

    Rivera, Tiffany; Zeeden, Christian; Storey, Michael

    2014-01-01

    and global correlation of records. The Quaternary time scale is anchored by 40Ar/39Ar ages on lava flows and ash layers where available, with stage boundaries and geomagnetic reversals including astronomically tuned records. However, astronomical dating has not yet validated the high-precision 238U/206Pb...... zircon and 40Ar/39Ar sanidine ages of the Bishop Tuff. We have identified the Bishop Tuff within the marine sedimentary record and derived an astronomical age of 0.765 ± 0.008 Ma by correlation to the LR04 δ18O global benthic stack and its age model. This age is consistent with Bishop Tuff radioisotopic...... ages, including new single crystal 40Ar/39Ar sanidine fusion analyses presented here, which demonstrates that concordance through multiple dating techniques is achievable within the Quaternary...

  4. Mo and Ni Removal from Drinking Water Using Zeolitic Tuff from Jordan

    Directory of Open Access Journals (Sweden)

    Khalil M. Ibrahim

    2016-11-01

    Full Text Available Mo and Ni metals could be hazardous in natural waters. The initial Mo and Ni concentration in the sampled domestic drinking water of north Jordan is 550 and 110 μg/L, respectively. The efficiency of using natural faujasite–phillipsite and phillipsite–chabazite tuffs in removing Mo and Ni from contaminated drinking water was tested. Batch experiments using different weights of the adsorbent were conducted at different contact times to determine the optimum conditions. The maximal uptake capacity of Mo from drinking water was equivalent to 440–420 μg/g adsorbent. The maximum removal efficiency of Mo by faujasite–phillipsite, phillipsite–chabazite, and the modified surfactant phillipsite–chabazite tuffs were 80%, 76%, and 78%, respectively. The proportional relationship between contact time and removal efficiency of Ni from water samples was observed. The maximum removal efficiency of Ni by the zeolitic tuffs is up to 90% compared to the original groundwater sample.

  5. Biological Web Service Repositories Review.

    Science.gov (United States)

    Urdidiales-Nieto, David; Navas-Delgado, Ismael; Aldana-Montes, José F

    2017-05-01

    Web services play a key role in bioinformatics enabling the integration of database access and analysis of algorithms. However, Web service repositories do not usually publish information on the changes made to their registered Web services. Dynamism is directly related to the changes in the repositories (services registered or unregistered) and at service level (annotation changes). Thus, users, software clients or workflow based approaches lack enough relevant information to decide when they should review or re-execute a Web service or workflow to get updated or improved results. The dynamism of the repository could be a measure for workflow developers to re-check service availability and annotation changes in the services of interest to them. This paper presents a review on the most well-known Web service repositories in the life sciences including an analysis of their dynamism. Freshness is introduced in this paper, and has been used as the measure for the dynamism of these repositories. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  6. Hydraulic Characterization of Overpressured Tuffs in Central Yucca Flat, Nevada Test Site, Nye County, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    K.J. Halford; R.J. Laczniak; D.L. Galloway

    2005-10-07

    A sequence of buried, bedded, air-fall tuffs has been used extensively as a host medium for underground nuclear tests detonated in the central part of Yucca Flat at the Nevada Test Site. Water levels within these bedded tuffs have been elevated hundreds of meters in areas where underground nuclear tests were detonated below the water table. Changes in the ground-water levels within these tuffs and changes in the rate and distribution of land-surface subsidence above these tuffs indicate that pore-fluid pressures have been slowly depressurizing since the cessation of nuclear testing in 1992. Declines in ground-water levels concurrent with regional land subsidence are explained by poroelastic deformation accompanying ground-water flow as fluids pressurized by underground nuclear detonations drain from the host tuffs into the overlying water table and underlying regional carbonate aquifer. A hydraulic conductivity of about 3 x 10-6 m/d and a specific storage of 9 x 10-6 m-1 are estimated using ground-water flow models. Cross-sectional and three-dimensional ground-water flow models were calibrated to measured water levels and to land-subsidence rates measured using Interferometric Synthetic Aperture Radar. Model results are consistent and indicate that about 2 million m3 of ground water flowed from the tuffs to the carbonate rock as a result of pressurization caused by underground nuclear testing. The annual rate of inflow into the carbonate rock averaged about 0.008 m/yr between 1962 and 2005, and declined from 0.005 m/yr in 2005 to 0.0005 m/yr by 2300.

  7. Backfill-waste interactions in repository simulating tests

    International Nuclear Information System (INIS)

    Sasaki, N.; Komarneni, S.; Scheetz, B.E.; Roy, R.

    1982-01-01

    Candidate backfill materials such as montmorillonite and clinoptilolite with and without the presence of simulated nuclear waste solids such as borosilicate glass, glass ceramic, sintered ceramic and supercalcine ceramic were investigated under repository simulating conditions (=300 0 C and 30MPa). Experiments were conducted under semi-wet as well as wet repository conditions. Montmorillonite and clinoptilolite did not seem to alter under both semi-wet and wet repository conditions as determined by XRD. However, the above backfill materials reacted extensively with wastes under both conditions. They altered to feldspar (oligoclase) in the presence of borosilicate glass and to analcime in the presence of particular ceramics under both semi-wet and wet repository conditions. Alteration of montmorillonite could not be detected either in the presence of the glass ceramic or supercalcine ceramic under both repository conditions. However, clinoptilolite altered to analcime in the presence of glass ceramic or supercalcine ceramic under wet repository conditions. Reactions of backfill materials with simulated wastes immobilized waste elements such as Cs, Mo, etc., by forming new phases such as analcime, oligoclase and powellite. In fact, analyses of product solutions from interaction runs indicated that the presence of backfill materials during the alteration of waste solids served to drastically reduce the concentration of some radionuclides in solutions. These results suggest that properly selected backfills can provide the simplest and most effective chemical (or thermodynamic) engineered barrier in an intelligently designed multibarrier system. Moreover, they indicate that the μ, P, and T in the usual leach tests are such that results of such tests cannot have any value in evaluating waste form behavior under repository conditions. 3 figures, 5 tables

  8. Ground water movements around a repository. Rock mechanics analyses

    International Nuclear Information System (INIS)

    Ratigan, J.L.

    1977-09-01

    The determination and rational assessment of groundwater flow around a repository depends upon the accurate analysis of several interdependent and coupled phenomenological events occuring within the rock mass. In particular, the groundwater flow pathways (joints) are affected by the excavation and thermomechanical stresses developed within the rock mass, and the properties, of the groundwater are altered by the temperature perturbations in the rock mass. The objective of this report is to present the results of the rock mechanics analysis for the repository excavation and the thermally-induced loadings. Qualitative analysis of the significance of the rock mechanics results upon the groundwater flow is provided in this report whenever such an analysis can be performed. Non-linear rock mechanics calculations have been completed for the repository storage tunnels and the global repository domain. The rock mass has been assumed to possess orthoganol joint sets or planes of weakness with finite strength characteristics. In the local analyses of the repository storage tunnels the effects of jointorientation and repository ventilation have been examined. The local analyses indicated that storage room support requirements and regions of strength failure are highly dependent upon joint orientation. The addition of storage tunnel ventilation was noted to reduce regions of strength failure, particularly during the 30 year operational phase of the repository. Examination of the local stresses around the storage tunnels indicated the potential for perturbed hydraulic permeabilities. The permeabilities can be expected to be altered to a greater degree by the stresses resulting from excavation than from stresses which are thermally induced. The thermal loading provided by the instantaneous waste emplacement resulted in stress states and displacements quite similar to those provided by the linear waste emplacement sequence

  9. Lithostratigraphy of the Calico Hills Formation and Prow Pass Tuff (Crater Flat Group) at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, T.C.; Geslin, J.K. [Science Applications International Corp., Las Vegas, NV (United States)

    1995-07-01

    Lithostratigraphic relations within the Calico Hills Formation and Prow Pass Tuff (Crater Flat Group) were reconstructed from analysis of core samples and observation of outcrop exposures. The Calico Hills Formation is composed of five nonwelded pyroclastic units (each formed of one or more pyroclastic-flow deposits) that overlie an interval of bedded tuff and a basal volcaniclastic sandstone unit. The Prow Pass Tuff is divided into four pyroclastic units and an underlying interval of bedded tuff. The pyroclastic units of the Prow Pass Tuff are distinguished by the sizes and amounts of their pumice and lithic clasts and their degree of welding. Pyroclastic units of the Prow Pass Tuff are distinguished from those of the Calico Hills Formation by their phenocryst assemblage, chemical composition, and ubiquitous siltstone lithic clasts. Downhole resistivity tends to mirror the content of authigenic minerals, primarily zeolites, in both for-mations and may be useful for recognizing the vitric-zeolite boundary in the study area. Maps of zeolite distribution illustrate that the bedded tuff and basal sandstone units of the Calico Hills Formation are altered over a wider area than the pyroclastic units of both the Calico Hills Formation and the upper Prow Pass Tuff.

  10. Lithostratigraphy of the Calico Hills Formation and Prow Pass Tuff (Crater Flat Group) at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Moyer, T.C.; Geslin, J.K.

    1995-01-01

    Lithostratigraphic relations within the Calico Hills Formation and Prow Pass Tuff (Crater Flat Group) were reconstructed from analysis of core samples and observation of outcrop exposures. The Calico Hills Formation is composed of five nonwelded pyroclastic units (each formed of one or more pyroclastic-flow deposits) that overlie an interval of bedded tuff and a basal volcaniclastic sandstone unit. The Prow Pass Tuff is divided into four pyroclastic units and an underlying interval of bedded tuff. The pyroclastic units of the Prow Pass Tuff are distinguished by the sizes and amounts of their pumice and lithic clasts and their degree of welding. Pyroclastic units of the Prow Pass Tuff are distinguished from those of the Calico Hills Formation by their phenocryst assemblage, chemical composition, and ubiquitous siltstone lithic clasts. Downhole resistivity tends to mirror the content of authigenic minerals, primarily zeolites, in both for-mations and may be useful for recognizing the vitric-zeolite boundary in the study area. Maps of zeolite distribution illustrate that the bedded tuff and basal sandstone units of the Calico Hills Formation are altered over a wider area than the pyroclastic units of both the Calico Hills Formation and the upper Prow Pass Tuff

  11. Sorption and desorption of remazol yellow by a Fe-zeolitic tuff

    International Nuclear Information System (INIS)

    Solache R, M. J.; Villalva C, R.; Diaz N, M. C.

    2010-01-01

    The adsorption of remazol yellow from aqueous solution was evaluated using a Fe-zeolitic tuff. The adsorbent was characterized by scanning electron microscopy, IR spectroscopy and X-ray diffraction. Sorption kinetic and isotherms were determined and the adsorption behavior was analyzed. Kinetic pseudo-second order and Langmuir-Freundlich models were successfully applied to the experimental results, indicating chemisorption on a heterogeneous material. The regeneration of the material was best accomplished by using a H 2 O 2 solution. The sorption capacity of the Fe-zeolitic tuff increased when the saturated samples were treated with a H 2O2 or FeCl 3 solution. (Author)

  12. Harvesting NASA's Common Metadata Repository

    Science.gov (United States)

    Shum, D.; Mitchell, A. E.; Durbin, C.; Norton, J.

    2017-12-01

    As part of NASA's Earth Observing System Data and Information System (EOSDIS), the Common Metadata Repository (CMR) stores metadata for over 30,000 datasets from both NASA and international providers along with over 300M granules. This metadata enables sub-second discovery and facilitates data access. While the CMR offers a robust temporal, spatial and keyword search functionality to the general public and international community, it is sometimes more desirable for international partners to harvest the CMR metadata and merge the CMR metadata into a partner's existing metadata repository. This poster will focus on best practices to follow when harvesting CMR metadata to ensure that any changes made to the CMR can also be updated in a partner's own repository. Additionally, since each partner has distinct metadata formats they are able to consume, the best practices will also include guidance on retrieving the metadata in the desired metadata format using CMR's Unified Metadata Model translation software.

  13. Oxygen isotopes and trace elements in the Tiva Canyon Tuff, Yucca Mountain and vicinity, Nye County, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, B.D.; Kyser, T.K.; Peterman, Z.E.

    1996-12-31

    Yucca Mountain is being studied as a potential site for an underground repository for high-level radioactive waste. Because Yucca Mountain is located in a resource-rich geologic setting, one aspect of the site characterization studies is an evaluation of the resource potential at Yucca Mountain. The Tiva Canyon Tuff (TCT) is a widespread felsic ash-flow sheet that is well exposed in the Yucca Mountain area. Samples of the upper part of the TCT were selected to evaluate the potential for economic mineral deposits within the Miocene volcanic section. These samples of the upper cliff and caprock subunits have been analyzed for oxygen isotopes and a large suite of elements. Oxygen isotope compositions ({delta}{sup 18}O) of the TCT are typical of felsic igneous rocks but range from 6.9 to 11.8 permil, indicating some post-depositional alteration. There is no evidence of the low {delta}{sup 18}O values (less than 6 permil) that are typical of epithermal precious-metal deposits in the region. The variation in oxygen isotope ratios is probably the result of deuteric alteration during late-stage crystallization of silica and low-temperature hydration of glassy horizons; these processes are also recorded by the chemical compositions of the rocks. However, most elemental contents in the TCT reflect igneous processes, and the effects of alteration are observed only in some of the more mobile elements. These studies indicate that the TCT at Yucca Mountain has not been affected by large-scale meteoric-water hydrothermal circulation. The chemical compositions of the TCT, especially the low concentrations of most trace elements including typical pathfinder elements, show no evidence for epithermal metal deposits. Together, these data indicate that the potential for economic mineralization in this part of the volcanic section at Yucca Mountain is small.

  14. Safety analysis methodologies for radioactive waste repositories in shallow ground

    International Nuclear Information System (INIS)

    1984-01-01

    The report is part of the IAEA Safety Series and is addressed to authorities and specialists responsible for or involved in planning, performing and/or reviewing safety assessments of shallow ground radioactive waste repositories. It discusses approaches that are applicable for safety analysis of a shallow ground repository. The methodologies, analysis techniques and models described are pertinent to the task of predicting the long-term performance of a shallow ground disposal system. They may be used during the processes of selection, confirmation and licensing of new sites and disposal systems or to evaluate the long-term consequences in the post-sealing phase of existing operating or inactive sites. The analysis may point out need for remedial action, or provide information to be used in deciding on the duration of surveillance. Safety analysis both general in nature and specific to a certain repository, site or design concept, are discussed, with emphasis on deterministic and probabilistic studies

  15. Gas generation and migration from radioactive waste repositories

    International Nuclear Information System (INIS)

    Agg, P.J.; Nash, P.J.; Rodwell, W.R.; Lineham, T.R.

    1995-01-01

    During the post-closure phase of a repository for low- and intermediate-level radioactive wastes significant quantities of gas will be generated, primarily by the anaerobic corrosion of metals and the degradation of organic wastes. A description is given of recent work carried out within the Nirex Safety Assessment Research Program to address the generation of gas within a repository and the migration of gas from the repository to the biosphere. Theoretical modeling capabilities have been developed to address both of these issues. In order to gain confidence in such theoretical models, it is important to validate model predictions against observed experimental data. Preliminary experiments carried out to help validate the modeling approaches are described

  16. An OAI repository centric peer-review model

    CERN Multimedia

    CERN. Geneva

    2005-01-01

    Pre-print repositories have seen a significant increase in use over the past fifteen years across multiple research domains. Researchers are beginning to develop applications capable of using these repositories to assist the scientific community above and beyond the pure dissemination of information. The contributions set forth by this paper emphasize a deconstructed publication model where in which the peer-review certification phase of a pre-print is mediated by an OAI-compliant peer-review service. This peer-review service uses a social-network algorithm for determining potential reviewers for a submitted manuscript and for weighting the influence of each participating reviewer’s evaluations. The paper also provides a set of peer-review specific metadata tags that can accompany a pre-prints existing metadata record. The combinations of these contributions provide a unique repository-centric peer-review model within the framework of the current OAI standards existing today.

  17. Some reflections on human intrusion into a nuclear waste repository

    International Nuclear Information System (INIS)

    Westerlind, M.

    2002-01-01

    This paper summarises some of the Swedish nuclear regulators' requirements and views related to intrusion into a repository for spent nuclear fuel, in the post-closure phase. The focus is however on experiences from the interaction with various stakeholders in the Swedish process for siting a repository. It is recognised that intrusion is not a major concern but that it is regularly raised in the debate, often in connection with issues related to retrievability. It is pointed out that more attention should be paid to the repository performance after an intrusion event, both in safety assessments and in communication with stakeholders, and not only address the immediate impacts to intruders. It is believed that international co-operation would be useful for developing methodologies for defining intrusion scenarios. (author)

  18. Triaxial- and uniaxial-compression testing methods developed for extraction of pore water from unsaturated tuff, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Mower, T.E.; Higgins, J.D.; Yang, I.C.

    1989-01-01

    To support the study of hydrologic system in the unsaturated zone at Yucca Mountain, Nevada, two extraction methods were examined to obtain representative, uncontaminated pore-water samples from unsaturated tuff. Results indicate that triaxial compression, which uses a standard cell, can remove pore water from nonwelded tuff that has an initial moisture content greater than 11% by weight; uniaxial compression, which uses a specifically fabricated cell, can extract pore water from nonwelded tuff that has an initial moisture content greater than 8% and from welded tuff that has an initial moisture content greater than 6.5%. For the ambient moisture conditions of Yucca Mountain tuffs, uniaxial compression is the most efficient method of pore-water extraction. 12 refs., 7 figs., 2 tabs

  19. Preservation of Records, Knowledge and Memory across generations. An International Project of the NEA/RWMC. Foundations and guiding principles for the preservation of records, knowledge and memory across generations: A focus on the post-closure phase of geological repositories. A Collective Statement of the NEA Radioactive Waste Management Committee

    International Nuclear Information System (INIS)

    2011-11-01

    Preservation of Records, Knowledge and Memory (RK and M) across generations is needed to support lengthy and complex decision-making processes across long operational and post-operational lifetimes of radioactive waste repositories. It is a recognised management task that spans unprecedented time-horizons in which technical, scientific, societal and cultural information is interwoven. Experience indicates that RK and M need to be actively managed from the start of the waste management programmes. Several radioactive waste disposal programmes are now approaching implementation. The NEA Radioactive Waste Management Committee (RWMC) has created an international project addressing the preservation of RK and M across generations. This collective statement summarises the current understanding of the relevant needs and challenges to be faced. It underscores the willingness of the RWMC member organisations to work together and support national programmes to move forward in this area. Research and development underway on the disposal of long-lived radioactive waste in engineered facilities or repositories located in deep geological formations has confirmed this form of disposal as the ultimate solution for the long-term protection of human beings and the environment, eliminating the need for human intervention and maintenance. While the intention is not to abandon repositories for geological disposal of radioactive waste, either before or after closure, as with many long-term projects, it is a question of minimising the risks of losing records, knowledge and memory (RK and M). The international community of radioactive waste professionals is leading advanced work in this important area. At the end of its first phase of RK and M work, the RWMC observed that the context has changed considerably since the 1980's, when RK and M preservation was thought to serve the sole function of deterring intrusion into a repository. The goal today is to preserve information for future

  20. Repository operational criteria comparative analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hageman, J.P.; Chowdhury, A.H. [Southwest Research Inst., San Antonio, TX (United States). Center for Nuclear Waste Regulatory Analyses

    1994-06-01

    The objective of the ``Repository Operational Criteria (ROC) Feasibility Studies`` (or ROC task) was to conduct comprehensive and integrated analyses of repository design, construction, and operations criteria in 10 CFR Part 60 regulations considering the interfaces among the components of the regulations and impacts of any potential changes to those regulations. The ROC task addresses regulatory criteria and uncertainties related to the preclosure aspects of the geologic repository. Those parts of 10 CFR Part 60 that require routine guidance or minor changes to the rule were addressed in Hageman and Chowdhury, 1992. The ROC task shows a possible need for further regulatory clarity, by major changes to the rule, related to the design bases and siting of a geologic repository operations area and radiological emergency planning in order to assure defense-in-depth. The analyses, presented in this report, resulted in the development and refinement of regulatory concepts and their supporting rationale for recommendations for potential major changes to 10 CFR Pan 0 regulations.

  1. Semantic repository and ontology mapping

    NARCIS (Netherlands)

    Gracia, J.; Trna, M.; Lozano, E.; Nguyen, T.T.; Gómez-Pérez, A.; Montaña, C.; Liem, J.

    2010-01-01

    This document discusses the core Semantic Technologies in DynaLearn: i) The semantic repository, which supports the online storage and access of qualitative reasoning models, ii) the grounding process, which establishes semantic equivalences between the concepts in the models and the concepts in a

  2. Cancer Epidemiology Data Repository (CEDR)

    Science.gov (United States)

    In an effort to broaden access and facilitate efficient data sharing, the Epidemiology and Genomics Research Program (EGRP) has created the Cancer Epidemiology Data Repository (CEDR), a centralized, controlled-access database, where Investigators can deposit individual-level de-identified observational cancer datasets.

  3. Apache Leap Tuff INTRAVAL experiments - results and lessons learned

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, T.C. [Univ. of Georgia, Athens, GA (United States); Rhodes, S.C.; Guzman, A.; Neuman, S.P. [Univ. of Arizona, Tucson, AZ (United States). Dept. of Hydrology and Water Resources

    1996-03-01

    Data from laboratory and field experiments in unsaturated fractured rock are summarized and interpreted for the purpose of evaluating conceptual and numerical models of fluid, heat and solute transport. The experiments were conducted at four scales, in small cores (2.5-cm long by 6-cm across), a large core (12-cm long by 10-cm across), a small block containing a single fracture (20 x 21 x 93 cm), and at field scales in boreholes (30-m long by 10-cm across) at three scales (1/2-, 1- and 3-meters). The smallest scale in the laboratory provided isothermal hydraulic and thermal properties of unfractured rock. Nonisothermal heat, fluid and solute transport experiments were conducted using the large core. Isothermal gas and liquid flow experiments were conducted in the fractured block. Field-scale experiments using air were used to obtain in situ permeability estimates as a function of the measurement scale. Interpretation of experimental results provides guidance for resolving uncertainties related to radionuclide migration from high level waste repositories in unsaturated fractured rock.

  4. Apache Leap Tuff INTRAVAL experiments - results and lessons learned

    International Nuclear Information System (INIS)

    Rasmussen, T.C.; Rhodes, S.C.; Guzman, A.; Neuman, S.P.

    1996-03-01

    Data from laboratory and field experiments in unsaturated fractured rock are summarized and interpreted for the purpose of evaluating conceptual and numerical models of fluid, heat and solute transport. The experiments were conducted at four scales, in small cores (2.5-cm long by 6-cm across), a large core (12-cm long by 10-cm across), a small block containing a single fracture (20 x 21 x 93 cm), and at field scales in boreholes (30-m long by 10-cm across) at three scales (1/2-, 1- and 3-meters). The smallest scale in the laboratory provided isothermal hydraulic and thermal properties of unfractured rock. Nonisothermal heat, fluid and solute transport experiments were conducted using the large core. Isothermal gas and liquid flow experiments were conducted in the fractured block. Field-scale experiments using air were used to obtain in situ permeability estimates as a function of the measurement scale. Interpretation of experimental results provides guidance for resolving uncertainties related to radionuclide migration from high level waste repositories in unsaturated fractured rock

  5. Felsic tuff from Rutland Island – A pyroclastic flow deposit in ...

    Indian Academy of Sciences (India)

    Felsic tuff from Rutland Island – A pyroclastic flow deposit in Miocene-sediments of Andaman-Java subduction complex. Tapan Pal. 1,∗. , Biswajit Ghosh. 2,∗∗. , Anindya Bhattacharya. 3 and S K Bhaduri. 4. 1. Petrology Division, ER, Geological Survey of India, Kolkata, India. 2. Department of Geology, University of Calcutta, ...

  6. Correlation of the oldest Toba Tuff to sediments in the central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Pattan, J.N.; ShyamPrasad, M.; Babu, E.V.S.S.K.

    and associated microtektites have been used to trace their provenance. In ODP site 758 from Ninetyeast Ridge, ash layer-D (13 cm thick, 0.73-0.75 Ma) and layer-E (5 cm thick, 0.77-0.78 Ma) were previously correlated to the oldest Toba Tuff (OTT) eruptions...

  7. Cerro Xalapaxco: An Unusual Tuff Cone with Multiple Explosion Craters, in Central Mexico (Puebla)

    Science.gov (United States)

    Abrams, M. J.; Siebe, C.

    1994-01-01

    The Xalapaxco tuff cone is located on the northeast flank of La Malinche stratovolcano in central Mexico. An unusually large number (10) of explosion craters, concentrated on the central and on the uphill side of the cone, expose alternating beds of stratified surge deposits and massive fall deposits.

  8. Performance prediction of mechanical excavators from linear cutter tests on Yucca Mountain welded tuffs

    International Nuclear Information System (INIS)

    Gertsch, R.; Ozdemir, L.

    1992-09-01

    The performances of mechanical excavators are predicted for excavations in welded tuff. Emphasis is given to tunnel boring machine evaluations based on linear cutting machine test data obtained on samples of Topopah Spring welded tuff. The tests involve measurement of forces as cutters are applied to the rock surface at certain spacing and penetrations. Two disc and two point-attack cutters representing currently available technology are thus evaluated. The performance predictions based on these direct experimental measurements are believed to be more accurate than any previous values for mechanical excavation of welded tuff. The calculations of performance are predicated on minimizing the amount of energy required to excavate the welded tuff. Specific energy decreases with increasing spacing and penetration, and reaches its lowest at the widest spacing and deepest penetration used in this test program. Using the force, spacing, and penetration data from this experimental program, the thrust, torque, power, and rate of penetration are calculated for several types of mechanical excavators. The results of this study show that the candidate excavators will require higher torque and power than heretofore estimated

  9. Occurrence of rhyolytic tuffs at deep sea drilling project site 219 on the Laccadive Ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Siddiquie, H.N.; Sukheswala, R.N.

    A study of thin sections from the lower and middle parts of Unit 5 (Paleocene) from Site 219 shows that these largely consist of acidic or rhyolitic tuffs. The overlying limestones in Unit 5 (Paleocene) and Unit 4 (Lower Eocene) also contain...

  10. Removal of Pb(II) from water by natural zeolitic tuff: Kinetics and thermodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Karatas, Mustafa, E-mail: mkaratas33@gmail.com [Aksaray University, Engineering Faculty, Department of Environmental Engineering, 68100 Aksaray (Turkey)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer Volcanic tuff is a natural zeolitic mineral. Black-Right-Pointing-Pointer It could help to remediate, to control or to prevent a possible pollution of water by lead. Black-Right-Pointing-Pointer Physicochemical interactions occur between lead cations and volcanic tuff particles in aqueous solution Black-Right-Pointing-Pointer Adsorption process follows second-order reaction kinetics and Langmuir adsorption isotherm adsorption process spontaneous and exothermic under natural conditions. - Abstract: The present study was aimed at examining the ability of a natural zeolitic volcanic tuff to remove Pb(II) ions from aqueous solutions under various conditions. The effects of various parameters such as optimum adsorbent mass, contact time, pH of the medium, Pb(II) concentration, and temperature were investigated. In addition, different adsorption isotherms were obtained using concentrations of Pb(II) ions ranging from 1 mg/L to 200 mg/L. The adsorption process follows second-order reaction kinetics and follows the Langmuir adsorption isotherm. The thermodynamic parameters are discussed in this article, including changes in Gibbs free energy, entropy, and enthalpy, for the adsorption of Pb(II) on tuff, and it is revealed that the adsorption process was spontaneous and exothermic under natural conditions. The maximum removal efficiency of 92% was obtained at a pH of 5 with a 25-min contact time for a 10 g/L solid-to-liquid ratio and an initial heavy metal concentration of 100 mg/L.

  11. Use of Rhenish tuff and trass in the Netherlands in the past two millenia

    NARCIS (Netherlands)

    Nijland, T.G.; Hees, R.P.J. van

    2017-01-01

    Occasionally, a profound but distant connection between volcanos and culture exists. This is the case for the volcanic Eifel region in Germany and historic construction in the Netherlands, with the river Rhine as physical and enabling connection. Volcanic tuff from the Eifel comprises a significant

  12. Maximum likelihood Bayesian averaging of airflow models in unsaturated fractured tuff using Occam and variance windows

    NARCIS (Netherlands)

    Morales-Casique, E.; Neuman, S.P.; Vesselinov, V.V.

    2010-01-01

    We use log permeability and porosity data obtained from single-hole pneumatic packer tests in six boreholes drilled into unsaturated fractured tuff near Superior, Arizona, to postulate, calibrate and compare five alternative variogram models (exponential, exponential with linear drift, power,

  13. Repositori Digital Berbasis Oai Dan Rantai Kutipan

    OpenAIRE

    Wibowo, Adi; Lim, Resmana

    2011-01-01

    Sebuah organisasi dapat memiliki sebuah repositori digital. Repositori digital adalah sebuah gudang file digitalyang dilengkapi dengan metadata untuk mendeskripsikan file-file digital tersebut. File digital dapat berasal daridalam organisasi tersebut, dan juga berasal dari organisasi eksternal yang mengijinkan koleksi file digitalnyadigunakan oleh umum. Untuk mengambil file digital dari repositori eksternal digunakan protokol terbuka yaituOpen Archives Initiative Protocol for Metadata Harvest...

  14. REPOSITORI DIGITAL BERBASIS OAI DAN RANTAI KUTIPAN

    OpenAIRE

    Wibowo, Adi; Lim, Resmana

    2011-01-01

    Sebuah organisasi dapat memiliki sebuah repositori digital. Repositori digital adalah sebuah gudang file digitalyang dilengkapi dengan metadata untuk mendeskripsikan file-file digital tersebut. File digital dapat berasal daridalam organisasi tersebut, dan juga berasal dari organisasi eksternal yang mengijinkan koleksi file digitalnyadigunakan oleh umum. Untuk mengambil file digital dari repositori eksternal digunakan protokol terbuka yaituOpen Archives Initiative Protocol for Metadata Harvest...

  15. Repositori Digital Berbasis Oai dan Rantai Kutipan

    OpenAIRE

    Wibowo, Adi; Lim, Resmana

    2011-01-01

    Sebuah organisasi dapat memiliki sebuah repositori digital. Repositori digital adalah sebuah gudang file digitalyang dilengkapi dengan metadata untuk mendeskripsikan file-file digital tersebut. File digital dapat berasal daridalam organisasi tersebut, dan juga berasal dari organisasi eksternal yang mengijinkan koleksi file digitalnyadigunakan oleh umum. Untuk mengambil file digital dari repositori eksternal digunakan protokol terbuka yaituOpen Archives Initiative Protocol for Metadata Harvest...

  16. Consistency analysis of network traffic repositories

    NARCIS (Netherlands)

    Lastdrager, Elmer; Lastdrager, E.E.H.; Pras, Aiko

    Traffic repositories with TCP/IP header information are very important for network analysis. Researchers often assume that such repositories reliably represent all traffic that has been flowing over the network; little thoughts are made regarding the consistency of these repositories. Still, for

  17. Consistency of Network Traffic Repositories: An Overview

    NARCIS (Netherlands)

    Lastdrager, E.; Lastdrager, E.E.H.; Pras, Aiko

    2009-01-01

    Traffc repositories with TCP/IP header information are very important for network analysis. Researchers often assume that such repositories reliably represent all traffc that has been flowing over the network; little thoughts are made regarding the consistency of these repositories. Still, for

  18. Eruption and deposition of the Fisher Tuff (Alaska)--Evidence for the evolution of pyroclastic flows

    Science.gov (United States)

    Burgisser, Alain; Gardner, J.E.; Stelling, P.

    2007-01-01

    Recognition that the Fisher Tuff (Unimak Island, Alaska) was deposited on the leeside of an ∼500–700‐m‐high mountain range (Tugamak Range) more than 10 km away from its source played a major role in defining pyroclastic flows as momentum‐driven currents. We reexamined the Fisher Tuff to evaluate whether deposition from expanded turbulent clouds can better explain its depositional features. We studied the tuff at 89 sites and sieved bulk samples from 27 of those sites. We find that the tuff consists of a complex sequence of deposits that record the evolution of the eruption from a buoyant plume (22 km) that deposited ∼0.2 km3 of dacite magma as a pyroclastic fall layer to erupting ∼10–100 km3 of andesitic magma as Scoria‐rich pyroclastic falls and flows that were mainly deposited to the north and northwest of the caldera, including those in valleys within the Tugamak Range. The distribution of the flow deposits and their welding, internal stratification, and the occurrence of lithic breccia all suggest that the pyroclastic flows were fed from a fountaining column that vented from an inclined conduit, the first time such a conduit has been recognized during a large‐volume caldera eruption. Pyroclastic flow deposits before and after the mountain range and thin veneer deposits high in the range are best explained by a flow that was stratified into a dense undercurrent and an overriding dilute turbulent cloud, from which deposition before the range was mainly from the undercurrent. When the flow ran into the mountain range, however, the undercurrent was blocked, but the turbulent cloud continued on. As the flow continued north, it restratified, forming another undercurrent. The Fisher Tuff thus records the passing of a flow that was significantly higher (800–1100 m thick) than the mountain range and thus did not require excessive momentum.

  19. Evenly-spaced columns in the Bishop Tuff as relicts of hydrothermal convection

    Science.gov (United States)

    Randolph-Flagg, N. G.; Breen, S. J.; Hernandez, A.; Self, S.; Manga, M.

    2015-12-01

    A few square km of the Bishop Tuff in eastern California, USA have evenly spaced erosional columns. These columns are more resistant to erosion due to the precipitation of the low-temperature zeolite (120-200 ºC), mordenite, which is not found in the surrounding tuff. Similar features observed in the Bandelier Tuff were hypothesized to form when cold water from above infiltrated into the still-hot tuff interior. This water would become gravitationally unstable and produced convection with steam upwellings and liquid water downwellings. These downwellings became cemented with mordenite while the upwellings were too dry for chemical reactions. We use two methods to quantitatively assess this hypothesis. First, scaling that ignores the effects of latent heat and mineral precipitation suggests the Rayleigh number (Ra, a measure of convective vigor) for this system is ~103 well above the critical Ra of 4π2. Second, to account for the effect of multiphase flow and latent heat, we use two-dimensional numerical models in the finite difference code HYDROTHERM. We find that the geometry of flow is consistent with field observations and confirm that geometry is sensitive to permeability and topography. These tests suggest a few things about low-pressure hydrothermal systems. 1) The geometry of at least some convection appears to be broadly captured by linear stability theory that ignores reactive transport, heterogeneity of host rock, and the effects of latent heat. 2) Topographic flow sets the wavelength of convection meaning that these columns formed somewhere without topography—probably a lake. Finally, these observations imply a wet paleoclimate in the Eastern Sierra namely that, in the aftermath of the Long Valley eruption, either rain or snow was able to pool in the caldera before the tuff cooled on the order of a hundred years after the eruption.

  20. 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

  1. Procedural method for the development of scenarios in the operational phase following closure of final repositories in deep geological formations. Report on the working package 1. Development of the international status of science and technology concerning methods and tools for operational and long-term safety cases; Vorgehensweise bei der Szenarienentwicklung in der Nachverschlussphase von Endlagern in tiefen geologieschen Formationen. Bericht zum Arbeitspaket 1. Weiterentwicklung des internationalen Stands von Wissenschaft und Technik zu Methoden und Werkzeugen fuer Betriebs- und Langzeitsicherheitsnachweise

    Energy Technology Data Exchange (ETDEWEB)

    Uhlmann, Stephan

    2016-09-15

    For the disposal of high-level radioactive wastes the disposal in deep geological formations is internationally favored. The safety cases include the scientific, technical, administrative and operational safety analyses and arguments, including the management system. According to IAEA the safety case includes site qualification, the design of the facility, construction and operation including an accident analysis, the closure phase and the post-closure phase. The safety case includes the evaluation of radiological risks for several scenarios. The report covers the methodology of scenario assumption in the post-closure phase of repositories in deep geological formations.

  2. Nuclear waste repository in basalt: preconceptual design guidelines

    Energy Technology Data Exchange (ETDEWEB)

    1979-06-01

    The development of the basalt waste isolation program parallels the growing need for permanent, environmentally safe, and secure means to store nuclear wastes. The repository will be located within the Columbia Plateau basalt formations where these ends can be met and radiological waste can be stored. These wastes will be stored such that the wastes may be retrieved from storage for a period after placement. After the retrieval period, the storage locations will be prepared for terminal storage. The terminal storage requirements will include decommissioning provisions. The facility boundaries will encompass no more than several square miles of land which will be above a subsurface area where the geologic makeup is primarily deep basaltic rock. The repository will receive, from an encapsulation site(s), nuclear waste in the form of canisters (not more than 18.5 feet x 16 inches in diameter) and containers (55-gallon drums). Canisters will contain spent fuel (after an interim 5-year storage period), solidified high-level wastes (HLW), or intermediate-level wastes (ILW). The containers (drums) will package the low-level transuranic wastes (LL-TRU). The storage capacity of the repository will be expanded in a time-phased program which will require that subsurface development (repository expansion) be conducted concurrently with waste storage operations. The repository will be designed to store the nuclear waste generated within the predictable future and to allow for reasonable expansion. The development and assurance of safe waste isolation is of paramount importance. All activities will be dedicated to the protection of public health and the environment. The repository will be licensed by the US Nuclear Regulatory Commission (NRC). Extensive efforts will be made to assure selection of a suitable site which will provide adequate isolation.

  3. Nuclear waste repository in basalt: preconceptual design guidelines

    International Nuclear Information System (INIS)

    1979-06-01

    The development of the basalt waste isolation program parallels the growing need for permanent, environmentally safe, and secure means to store nuclear wastes. The repository will be located within the Columbia Plateau basalt formations where these ends can be met and radiological waste can be stored. These wastes will be stored such that the wastes may be retrieved from storage for a period after placement. After the retrieval period, the storage locations will be prepared for terminal storage. The terminal storage requirements will include decommissioning provisions. The facility boundaries will encompass no more than several square miles of land which will be above a subsurface area where the geologic makeup is primarily deep basaltic rock. The repository will receive, from an encapsulation site(s), nuclear waste in the form of canisters (not more than 18.5 feet x 16 inches in diameter) and containers (55-gallon drums). Canisters will contain spent fuel (after an interim 5-year storage period), solidified high-level wastes (HLW), or intermediate-level wastes (ILW). The containers (drums) will package the low-level transuranic wastes (LL-TRU). The storage capacity of the repository will be expanded in a time-phased program which will require that subsurface development (repository expansion) be conducted concurrently with waste storage operations. The repository will be designed to store the nuclear waste generated within the predictable future and to allow for reasonable expansion. The development and assurance of safe waste isolation is of paramount importance. All activities will be dedicated to the protection of public health and the environment. The repository will be licensed by the US Nuclear Regulatory Commission (NRC). Extensive efforts will be made to assure selection of a suitable site which will provide adequate isolation

  4. Repository Subsurface Preliminary Fire Hazard Analysis

    International Nuclear Information System (INIS)

    Logan, Richard C.

    2001-01-01

    This fire hazard analysis identifies preliminary design and operations features, fire, and explosion hazards, and provides a reasonable basis to establish the design requirements of fire protection systems during development and emplacement phases of the subsurface repository. This document follows the Technical Work Plan (TWP) (CRWMS M and O 2001c) which was prepared in accordance with AP-2.21Q, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities''; Attachment 4 of AP-ESH-008, ''Hazards Analysis System''; and AP-3.11Q, ''Technical Reports''. The objective of this report is to establish the requirements that provide for facility nuclear safety and a proper level of personnel safety and property protection from the effects of fire and the adverse effects of fire-extinguishing agents

  5. Repository Subsurface Preliminary Fire Hazard Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Richard C. Logan

    2001-07-30

    This fire hazard analysis identifies preliminary design and operations features, fire, and explosion hazards, and provides a reasonable basis to establish the design requirements of fire protection systems during development and emplacement phases of the subsurface repository. This document follows the Technical Work Plan (TWP) (CRWMS M&O 2001c) which was prepared in accordance with AP-2.21Q, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities''; Attachment 4 of AP-ESH-008, ''Hazards Analysis System''; and AP-3.11Q, ''Technical Reports''. The objective of this report is to establish the requirements that provide for facility nuclear safety and a proper level of personnel safety and property protection from the effects of fire and the adverse effects of fire-extinguishing agents.

  6. Recommended versus Certified Repositories: Mind the Gap

    Directory of Open Access Journals (Sweden)

    Sean Edward Husen

    2017-09-01

    Full Text Available Researchers are increasingly required to make research data publicly available in data repositories. Although several organisations propose criteria to recommend and evaluate the quality of data repositories, there is no consensus of what constitutes a good data repository. In this paper, we investigate, first, which data repositories are recommended by various stakeholders (publishers, funders, and community organizations and second, which repositories are certified by a number of organisations. We then compare these two lists of repositories, and the criteria for recommendation and certification. We find that criteria used by organisations recommending and certifying repositories are similar, although the certification criteria are generally more detailed. We distil the lists of criteria into seven main categories: “Mission”, “Community/Recognition”, “Legal and Contractual Compliance”, “Access/Accessibility”, “Technical Structure/Interface”, “Retrievability” and “Preservation”. Although the criteria are similar, the lists of repositories that are recommended by the various agencies are very different. Out of all of the recommended repositories, less than 6% obtained certification. As certification is becoming more important, steps should be taken to decrease this gap between recommended and certified repositories, and ensure that certification standards become applicable, and applied, to the repositories which researchers are currently using.

  7. University digital repositories and authors.

    Directory of Open Access Journals (Sweden)

    Alice Keefer

    2008-02-01

    Full Text Available The Open Access movement offers two strategies for making scientific information available without economic, technical or legal obstacles: the publication of articles in OA journals and the deposit by authors of their Works in stable institutional or discipline-based repositories. This article explores the implementation of the second “route” on the part of authors, because it is the strategy that offers the greatest possibility of attaining OA in the short term. However, it does require repositories to exert great effort in informing the authors of the advantages of self-archiving and of the procedures for depositing their work and, even helping them to do so – through services and promotional activities.

  8. Possible radiological consequences of the clearance according paragraph 29 StrlSchV for the reuse of repository in the post-operative phase and the time after release from follow-up maintenance; Moegliche radiologische Folgen der Freigabe zur Beseitigung nach paragraph 29 StrlSchV bei der Nachnutzung einer Deponie in der Nachsorgephase und in der Zeit nach der Entlassung aus der Nachsorge

    Energy Technology Data Exchange (ETDEWEB)

    Kueppers, Christian; Claus, Manuel; Ustohalova, Veronika

    2016-11-15

    The report summarizes the regulations for the post-operative phase of a repository and the base- and surface sealing for the time after release form the follow-up maintenance. Possible radiation exposure due to the radioactive wastes released for disposal during and after the post-operative maintenance cover possible radiation exposures under faultless surface sealing and in case of deficient surface sealing systems.

  9. Repository development status in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Beceiro, Alvaro; Zuloaga, Pablo [ENRESA (Spain)

    2009-06-15

    The paper describes the status of repository development for the different waste categories. Low and Intermediate Waste Disposal facility of El Cabril was commissioned in 1992 and is in normal operation. The major modifications and activities during the last years are the adaptation to waste streams not initially foreseen such as some decommissioning waste or waste from steel industry, and the improvement of its performance assessment, supported by a R and D and refined models. As part of this facility, a new disposal facility specifically intended for very low activity waste has been constructed and commissioned in July 2008. Its design is based on the European Directive for hazardous waste disposal. National policy for Nuclear Spent Fuel and High-Level waste is focused on the development of a centralized storage facility of the vault type, whose site location would be selected through a volunteering process. Meanwhile, with the aim of solving specific problems, three individual storage facilities are in different status at reactor sites. Research on final solution, including some repository aspects as well as separation and transmutation are being carried out in accordance to ENRESA's R and D program. ENRESA has developed conceptual designs for non site specific repositories, both in granite and clay, and has carried out their corresponding performance assessment exercises. (authors)

  10. Conceptual design of the Brazilian near surface repository

    International Nuclear Information System (INIS)

    Mourao, Rogerio P.; Freire, Carolina Braccini

    2013-01-01

    CNEN is presently in the planning phase of the implementation of a repository for low and intermediate level wastes. One of the present activities of this project is to define a concept for the disposal of radioactive wastes to be received. The conceptual design of the repository takes into account the quantities and characteristics of the waste, the disposal arrangement, the waste acceptance criteria, the site characteristics, the period of the facility operation and institutional control, the engineering barriers to be used, as well as the facility's operational aspects. The facility will be a near-surface repository, an internationally accepted concept and adopted for example in France (L'Aube repository) and Spain (El Cabril). An acceptable site for such a repository must have characteristics that minimize the risk of human exposure to the radiation and environmental contamination. For this, the chosen site must meet specific technical and socioeconomic requirements, such as favorable physiographic, meteorological, geotechnical and tectonic characteristics, low demographic density, absence of agricultural activities and mineral deposits and proximity to the paved road grid. In this work the technical and socioeconomic requirements necessary and sufficient for site selection are presented. Also discussed is the method for the establishment of the main features that the different facility's buildings must have. Since a specific site has not yet been selected, a simulated area with straight and parallel sides, no gradient, served by access road and having a surface sufficient to hold the disposal structures and support facilities, as well as the legal exclusion zones. The buildings were designed and positioned in order to meet the needs in terms of flow of waste, personnel, supplies and materials necessary to perform the activities within the enterprise. The methodology for compilation of information related to buildings is presented. This information will be

  11. Zoning Characteristics of the Devine Canyon Tuff, an Extremely Widespread High-silica Rhyolite Ash-flow Tuff: Constraints for Rhyolite Evolution Models

    Science.gov (United States)

    Isom, S. L.; Shafer, E.; Streck, M. J.

    2016-12-01

    Large volume (>100 km3) ignimbrites provide a snapshot into the evolution of voluminous batches of rhyolite that have accumulated at shallow depth. Researchers have been studying such deposits for decades to constrain the generation, accumulation and evolution of voluminous rhyolites. Despite this, evolution models for large volume rhyolite bodies remain controversial. The 9.7 Ma Devine Canyon Tuff (DCT) is a large volume ( 200-300 km3), thin, high-silica rhyolite ignimbrite in eastern Oregon with a presumed source in the Harney Basin south of Burns. The tuff, a single cooling unit, likely covered an area in excess of 30,000 km2 originally. The DCT ranges from non- to densely welded, vitric to devitrified, and pumice poor to pumice rich. Phenocryst content of bulk tuff ranges from 5 to 30% and samples indicate strong incompatible trace element zonation (e.g. [in ppm], Rb: 90-154, Zr: 790-1330, Y: 96-151, Nb: 54-92). Pumice analyses slightly extend the range of rhyolite compositions seen in bulk rock and indicate the existence of a minor andesitic to dacitic component found as streaks in banded pumices or as individual pumice clasts. The compositional range is further extended by including pumices from fallout deposits that occur at a few places immediately below the ignimbrite. Detailed mineral data from a select set of pumices, including fallout, indicate rhyolite magmas range in crystallinity from 3 to 19% and dacite magma is at 22%, yet size distribution of phenocrysts among rhyolites, especially in dacite magma, changes. Sanidine compositions are narrow within rhyolites (Ab: 54-59, Or: 46-41, An: 0-1) while sanidine from the dacite pumice trends away from rhyolitic compositions (Ab: 65-66, Or: 29-27, An: 6-7). Composition of mafic silicates (Fe-rich cpx and fayalite) are mostly overlapping across all pumice compositions. Current distribution data indicate different rhyolites are found throughout the entire Devine Canyon Tuff with limited compositional

  12. Iridium content of basaltic tuffs and enclosing black shales of the balder formation, North Sea

    Science.gov (United States)

    Crawford Elliott, W.; Aronson, James L.; Millard, Hugh T., Jr.

    1992-07-01

    The anomalous levels of Ir and the presence of shocked metamorphosed quartz deposited at the Cretaceous/Tertiary (K/T) boundary worldwide is strong evidence that a meteorite impact took place during the K/T boundary interval. However, because of observed high Ir contents at Kilauea vents, it is still a major point of contention that the Ir anomaly could have been produced by flood basaltic volcanism. This might especially be true at Stevns Klint, Denmark, where the K/T boundary marl contains pyroclastic labradorite and Mg-smectite thought to have been produced by basaltic volcanism. However, up to now, no study has determined whether or not a depositional Ir anomaly has formed in association with a known major basaltic eruption. Herein, we report the concentrations of Ir, Pt, Au, and Ag in basaltic tuffs and enclosing marine black shales of the widespread Paleocene-Eocene Balder Formation. The tuffs in the Balder Formation represent explosive basaltic volcanism associated with the major volcano/tectonic activity of the opening of the northern North Atlantic Ocean. As such, they are the kind of eruption that could have possibly created a global K/T boundary-type Ir anomaly. Our results show that the tuffs and the shales on a per-weight basis both contain concentrations of Ir (0.1-0.25 ppb) that are higher than the Ir levels recently measured from terrestrial rocks including the Deccan Trap and Columbia River flood basalts, but are comparable to Hawaiian and Reunion Island basalts. Because of its thickness, the absolute amount of Ir expelled during the eruption of the main tuff sequence of the Balder Tuff is sizable. Yet for such an eruption to have produced a global Ir anomaly would mandate it having been one of an extremely high volatile content and it would have to have been erupted over a very short interval of time. Furthermore, such a high proportion of the volatilized Ir would have to have been injected into the stratosphere so that only small enrichments of

  13. Update on the national low level radioactive waste repository study

    International Nuclear Information System (INIS)

    Veitch, S.M.

    1997-01-01

    Activity to establish a national repository for low-level and short-lived intermediate-level radioactive waste in Australia began in the early 1980's. From the early 1990's computer-based geographic information systems had developed sufficiently so that all of Australia could be quickly reviewed using digital data relevant to site selection criteria. A three-phased approach to site selection was commenced which included an iterative process of data collection, interpretation, and public involvement through discussion papers. All of Australia was reviewed using national-scale data, and eight broad regions were identified and reviewed using regional-scale data. A third phase report will be released shortly which includes details on the process for identifying the preferred region of the eight. This region will be the focus for public involvement and for detailed study to identify a site for the national repository

  14. General conceptual design study for a high-level radioactive waste repository in a granite formation

    International Nuclear Information System (INIS)

    1982-01-01

    The object of the general conceptual design study for a high level radioactive wastes repository in a deep lying granite formation is to ensure that technology available in 1980 is suitable for building, operating and finally closing such a repository. It is feasible to build and operate a 1000 m deep repository, located in a granite batholith, receiving 30000 AVM canisters (after 30 years surface cooling), the disposal rate being 1000 canisters per year. Cost of the operation amounts to 1,3% of the corresponding amount of electricity. The building, operating and final closing phases will take 81 years

  15. Planning and Design Considerations for Geological Repository Programmes of Radioactive Waste

    International Nuclear Information System (INIS)

    2014-11-01

    Disposal in a geological repository is the generally accepted solution for the long term management of high level and/or long lived radioactive wastes, in line with the general principles defined in the IAEA Safety Fundamentals. This publication presents practical information on the way a geological repository programme for radioactive waste could be defined and planned, with special attention to all aspects having an impact on the timing. Country specific examples for repository development phases are provided, based on actual experiences from Member States

  16. Post Closure Safety of the Morsleben Repository

    International Nuclear Information System (INIS)

    Preuss, J.; Eilers, G.; Mauke, R.; Moeller-Hoeppe, N.; Engelhardt, H.-J.; Kreienmeyer, M.; Lerch, C.; Schrimpf, C.

    2002-01-01

    After the completion of detailed studies of the suitability the twin-mine Bartensleben-Marie, situated in the Federal State of Saxony-Anhalt (Germany), was chosen in 1970 for the disposal of low and medium level radioactive waste. The waste emplacement started in 1978 in rock cavities at the mine's fourth level, some 500 m below the surface. Until the end of the operational phase in 1998 in total about 36,800 m 3 of radioactive waste was disposed of. The Morsleben LLW/ILW repository (ERAM) is now under licensing for closure. After completing the licensing procedure the repository will be sealed and backfilled to exclude any undue future impact onto man or the environment. The main safety objective is to protect the biosphere from the harmful effects of the disposed radionuclides. Furthermore, classical or conventional requirements call for ruling out or minimizing other unfavorable environmental effects. The ERAM is an abandoned rock salt and potash mine. As a consequence it has a big void volume, however small parts of the cavities are backfilled with crushed salt rocks. Other goals of the closure concept are therefore a long-term stabilization of the cavities to prevent a dipping or buckling of the ground surface. In addition, groundwater protection shall be assured. For the sealing of the repository a closure concept was developed to ensure compliance with the safety protection objectives. The concept anticipates the backfilling of the cavities with hydraulically setting backfill materials (salt concretes). The reduction of the remaining void volume in the mine causes in the case of brine intrusions a limitation of the leaching processes of the exposed potash seams. However, during the setting process the hydration heat of the concrete will lead to an increase of the temperature and hence to thermally induced stresses of the concrete and the surrounding rocks. Therefore, the influence of these stresses and deformations on the stability of the salt body and the

  17. Sorption and desorption of remazol yellow by a Fe-zeolitic tuff

    Energy Technology Data Exchange (ETDEWEB)

    Solache R, M. J. [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Villalva C, R.; Diaz N, M. C., E-mail: marcos.solache@inin.gob.m [Instituto Tecnologico de Toluca, Division de Estudios del Posgrado, Av. Tecnologico s/n, Ex-Rancho La Virgen, 52140 Metepec, Estado de Mexico (Mexico)

    2010-07-01

    The adsorption of remazol yellow from aqueous solution was evaluated using a Fe-zeolitic tuff. The adsorbent was characterized by scanning electron microscopy, IR spectroscopy and X-ray diffraction. Sorption kinetic and isotherms were determined and the adsorption behavior was analyzed. Kinetic pseudo-second order and Langmuir-Freundlich models were successfully applied to the experimental results, indicating chemisorption on a heterogeneous material. The regeneration of the material was best accomplished by using a H{sub 2}O{sub 2} solution. The sorption capacity of the Fe-zeolitic tuff increased when the saturated samples were treated with a H{sub 2O2} or FeCl{sub 3} solution. (Author)

  18. Criticality characteristics of mixtures of plutonium, silicon dioxide, Nevada tuff, and water

    International Nuclear Information System (INIS)

    Sanchez, R.G.; Myers, W.; Stratton, W.

    1996-01-01

    The major objective of this study has been to examine the possibility of a nuclear explosion should 50 to 100 kg of plutonium be mixed with SiO 2 , vitrified, placed within a heavy steel container, and buried in the material known as Nevada tuff. To accomplish this objective, the authors have created a survey of critical states or configurations of mixtures of plutonium, SiO 2 , tuff, and water and examined these data to determine those configurations that might be unstable or autocatalytic. They have identified regions of criticality instability with the possibility of autocatalytic power behavior. Autocatalytic behavior is possible but improbable, for a very limited range of wet systems

  19. Studies of the mobility of uranium and thorium in Nevada Test Site tuff

    Energy Technology Data Exchange (ETDEWEB)

    Wollenberg, H.A.; Flexser, S.; Smith, A.R. [Lawrence Berkeley Lab., CA (United States)

    1991-06-01

    Hydro-geochemical processes must be understood if the movement of radionuclides away from a breached radioactive waste canister is to be modeled and predicted. In this respect, occurrences of uranium and thorium in hydrothermal systems are under investigation in tuff and in rhyolitic tuff that was heated to simulate the effects of introduction of radioactive waste. In these studies, high-resolution gamma spectrometry and fission-track radiography are coupled with observations of alteration mineralogy and thermal history to deduce the evidence of, or potential for movement of, U and Th in response to the thermal environment. Observations to date suggest that U was mobile in the vicinity of the heater but that localized reducing environments provided by Fe-Ti-Mn-oxide minerals concentrated U and thus attenuated its migration.

  20. Microautoradiography in studies of Pu(V) sorption by trace and fracture minerals in tuff

    International Nuclear Information System (INIS)

    Vaniman, D.; Furlano, A.; Chipera, S.; Thompson, J.; Triay, I.

    1996-01-01

    Microautoradiography was used to evaluate the mineralogic basis of Pu(V) retention by tuffs from Yucca Mountain, Nevada. Altered orthopyroxenes and oxide minerals are associated with high Pu retention but are limited to specific stratigraphic horizons. A weaker but more general association of Pu with smectite occurs in most samples. Thin-sections that cross fractures allow comparative studies of Pu retention by fracture-lining versus matrix minerals. Using Ag metal in emulsions as a measure of underlying Pu concentration, electron-microprobe analysis can quantify Pu retention along fracture walls and provide mineral/mineral Pu retention factors. For smectite-lined microfractures in zeolitized tuff, the smectite/clinoptilolite Pu retention factor is >80

  1. Strontium isotope evolution of pore water and calcite in the Topopah Spring Tuff, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Marshall, Brian D.; Futa, Kiyoto

    2001-01-01

    Pore water in the Topopah Spring Tuff has a narrow range of (delta) 87 Sr values that can be calculated from the (delta) 87 Sr values of the rock considering advection through and reaction with the overlying nonwelded tuffs of the PTn. This model can be extended to estimate the variation of (delta) 87 Sr in the pore water through time; this approximates the variation of (delta) 87 Sr measured in calcite fracture coatings. In samples of calcite where no silica can be dated by other methods, strontium isotope data may be the only method to determine ages. In addition, other Sr-bearing minerals in the calcite and opal coatings, such as fluorite, may be dated using the same model

  2. Experiences of fitting isotherms to data from batch sorption experiments for radionuclides on tuffs

    International Nuclear Information System (INIS)

    Polzer, W.L.; Fuentes, H.R.

    1989-11-01

    Laboratory experiments have been performed on the sorption of radionuclides on tuff as site characterization information for the Yucca Mountain Project. This paper presents general observations on the results of curve-fitting of sorption data by isotherm equations and the effects of experimental variables on their regressional analysis. Observations are specific to the effectiveness and problems associated with fitting isotherms, the calculation and value of isotherm parameters, and the significance of experimental variables such as replication, particle size, mode of sorption, and mineralogy. These observations are important in the design of laboratory experiments to ensure that collected data are adequate for effectively characterizing sorption of radionuclides on tuffs or other materials. 13 refs., 2 figs., 4 tabs

  3. An evaluation of repository-induced disturbances for a KBS-3 type repository

    International Nuclear Information System (INIS)

    Savage, D.; McLeod, R.; McEwen, T.

    1998-03-01

    This report considers the potential physical and chemical perturbations caused by the excavation, operation and backfilling and sealing of a KBS-3 type repository for spent fuel in Sweden. Parts of the underground excavations are likely to remain open to the atmosphere for up to several decades. Time-dependent changes to the chemical environment and the properties of the geological formation will be occurring as well as the initial disturbance of construction and subsequent changes after backfilling. In addition, this report also discusses issues that arise from the co-disposal of spent fuel and intermediate level waste. The processes which are likely to act during each stage of a repository from construction through to backfilling and sealing have been reviewed and the degree to which these processes are understood and represented within the performance assessment is discussed. The areas of particular interest are: The coupling of thermal, hydrogeological and mechanical processes with particular reference to the development of the near-field; Understanding the transient process of re-saturation with particular reference to the buffer material surrounding the waste canisters, including chemical changes to the material; The impact of accidental events during the construction and operational phases of work and their possible consequence on the long term performance of the repository; Chemical issues relating to the co-disposal of spent fuel and intermediate level wastes within a single facility. When consideration of transient processes and coupling is discussed, it is apparent that numerical tools and a complete understanding to provide quantitative information is lacking. The importance of the engineered barrier system within the performance assessment for spent fuel disposal is recognised and the emphasis is placed on the understanding of the coupled processes in the evolution in the near-field of the geosphere

  4. FRACTURE GEOMETRY ANALYSIS FOR THE STRATIGRAPHIC UNITS OF THE REPOSITORY HOST HORIZON

    International Nuclear Information System (INIS)

    Hardin, E.

    2000-01-01

    The purpose of this Analysis and Model Report (AMR) is to evaluate the geometry of the primary joint sets (i.e., fractures belonging to a group demonstrating a preferential orientation) associated with the lithostratigraphic units of the Repository Host Horizon (RHH). Specifically, the analysis is limited to examining joint sets occurring within the upper lithophysal (Tptpul), middle nonlithophysal (Tptpmn), lower lithophysal (Tptpll), and lower non-lithophysal (Tptpln) zones of the crystal-poor member of the Topopah Spring Tuff. The results of this AMR supply the geometric input parameters for the joint sets used as input to the acquired software code DRKBA V3.3 (CRWMS M and O 2000i; hereafter DRKBA), which is used in the determination of key block sizes and distributions within the ''Drift Degradation Analysis'' AMR (CRWMS M and O 2000b). Additionally, the results of this AMR provide input for selecting the orientation of the emplacement drifts used in layout design work for the potential repository

  5. Seismic considerations in sealing a potential high-level radioactive waste repository

    International Nuclear Information System (INIS)

    Fernandez, J.A.; Richardson, A.M.; Lin, Ming

    1992-01-01

    The potential repository system is intended to isolate high-level radioactive waste at Yucca Mountain. One subsystem that may contribute to achieving this objective is the sealing subsystem. This subsystem is comprised of sealing components in the shafts, ramps, underground network of drifts, and the exploratory boreholes. Sealing components can be rigid, as in the case of a shaft seal, or can be more compressible, as in the case of drift fill comprised of mined rockfill. This paper presents the preliminary seismic response of discrete sealing components in welded and nonwelded tuff. Special consideration is given to evaluating the stress in the seal, and the behavior of the interface between the seal and the rock. The seismic responses are computed using both static and dynamic analyses. Also presented is an evaluation of the maximum seismic response encountered by a drift seal with respect to the angle of incidence of the seismic wave. Mitigation strategies and seismic design considerations are proposed which can potentially enhance the overall response of the sealing component and subsequently, the performance of the overall repository system

  6. Magnetic links among lava flows, tuffs and the underground plumbing system in a monogenetic volcano, derived from magnetics and paleomagnetic studies

    Science.gov (United States)

    Urrutia-Fucugauchi, Jaime; Trigo-Huesca, Alfonso; Pérez-Cruz, Ligia

    2012-12-01

    A combined study using magnetics and paleomagnetism of the Toluquilla monogenetic volcano and associated lavas and tuffs from Valsequillo basin in Central Mexico provides evidence on a 'magnetic' link between the lavas, ash tuffs and the underground volcanic conduit system. Paleomagnetic analyses show that the lava and ash tuff carry reverse polarity magnetizations, which correlate with the inversely polarized dipolar magnetic anomaly over the volcano. The magnetizations in the lava and tuff show similar southward declinations and upward inclinations, supporting petrological inferences that the tuff was emplaced while still hot and indicating a temporal correlation for lava and tuff emplacement. Modeling of the dipolar anomaly gives a reverse polarity source magnetization associated with a vertical prismatic body with southward declination and upward inclination, which correlates with the reverse polarity magnetizations in the lava and tuff. The study documents a direct correlation of the paleomagnetic records with the underground magmatic conduit system of the monogenetic volcano. Time scale for cooling of the volcanic plumbing system involves a longer period than the one for the tuff and lava, suggesting that magnetization for the source of dipolar anomaly may represent a long time average as compared to the spot readings in the lava and tuff. The reverse polarity magnetizations in lava and tuff and in the underground source body for the magnetic anomaly are interpreted in terms of eruptive activity of Toluquilla volcano at about 1.3 Ma during the Matuyama reverse polarity C1r.2r chron.

  7. Removal of ammonia from waste air streams with clinoptilolite tuff in its natural and treated forms

    Czech Academy of Sciences Publication Activity Database

    Ciahotný, K.; Melenová, L.; Jirglová, H.; Prokopová, Olga; Kočiřík, Milan; Eić, M.

    2006-01-01

    Roč. 12, č. 3 (2006), s. 219-226 ISSN 0929-5607 R&D Projects: GA ČR GA104/00/1007; GA ČR GP104/03/D183 Institutional research plan: CEZ:AV0Z40400503 Keywords : clinoptilolite tuffs * ammonia * adsorption * impregnation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.590, year: 2006

  8. Hydrothermal conditions around a radioactive waste repository

    International Nuclear Information System (INIS)

    Thunvik, R.; Braester, C.

    1981-12-01

    Numerical solutions for the hydrothermal conditions around a hard rock repository for nuclear fuel waste are presented. The objective of the present investigation is to illustrate in principle the effect of heat released from a hypothetical radioactive waste repository with regard to anisotropy in the rock permeability. Permeability and porosity are assumed to be constant or to decrease exponentially with depth. The hypothetical repository is situated below a horizontal ground surface or below the crest of a hill, and it is assumed that the water table follows the topography. Major interest in the analysis is directed towards the influence of anisotropy in the permeability on the flow patterns and travel times for water particles, being traced from the repository to the ground surface. The presented results show that anisotropy in the permeability may have a significant influence on the flow conditions around the repository and subsequently also on the travel times from the repository. (Authors)

  9. People's perception of LILW repository

    International Nuclear Information System (INIS)

    Zeleznik, Nadja; Polic, Marko

    2002-01-01

    Full text: Social acceptability of the radioactive waste repository presents a great problem in every country with such a waste. Even if people agree with the need for its construction, the chosen location should be far from their homes (NIMBY). The reasons for such attitudes were attributed to different causes: uneducated public, differences in understanding of radioactivity and risk by experts and lay public, risk communication problems, lack of credibility and social trust, etc. While in earlier days public was blamed for its irrationality, and need for education and information was emphasized, today it is realized that public trust is extremely important if effective risk communication is to be achieved. It is also recognized that it is not so much the content of the risk message itself, as the lack of trust to those responsible for provision of information that is behind this opposition. Perhaps we could apply here Petty and Caciopo's elaboration likelihood model of persuasion, with credibility as a factor in peripheral route of persuasion. Nevertheless also general lowering of social trust should explain social non-agreement. This lack of trust in experts and political institutions is perhaps caused by outwitting public in earlier years, its bad experiences with responsible officials, dangerous accidents (e.g. TMI, Chernobyl), increased influence that professions have over people's welfare, a greater value placed on equality and better educated public, etc. In 1996 the ARAO re-initiated the search for a LILW repository location with a new, so-called combined approach to the site selection, where the technical, geologically led process is combined with participation of local community. In order to get information on people's perception of the LILW repository construction, their willingness to accept it and factors that influence the acceptability, several surveys have been conducted. Groups of experts and lay persons answered the questionnaires. The results of

  10. Subsurface deformation in hypervelocity cratering experiments into high-porosity tuffs

    Science.gov (United States)

    Winkler, Rebecca; Poelchau, Michael H.; Moser, Stefan; Kenkmann, Thomas

    2016-10-01

    Hypervelocity impact experiments on porous tuff targets were carried out to determine the effect of porosity on deformation mechanisms in the crater's subsurface. Blocks of Weibern Tuff with about 43% porosity were impacted by 2.5 mm and 12.0 mm diameter steel spheres with velocities between 4.8 km s-1 and 5.6 km s-1. The postimpact subsurface damage was quantified with computer tomography as well as with meso- and microscale analyses of the bisected crater subsurface. The intensity and style of deformation in mineral clasts and the tuff matrix were mapped and their decay with subsurface depth was determined. Subsurface deformation styles include pore space compaction, clast rotation, as well as microfracture formation. Evaluation of the deformation indicates near-surface energy coupling at a calculated depth of burial of 2 projectile diameters (dp), which is in conflict with the crater shape, which displays a deep, central penetration tube. Subsurface damage extends to 2 dp beneath the crater floor in the experiments with 2.5 mm projectiles and increases to 3 dp for 12 mm projectiles. Based on overprinting relationships and the geometrical orientation of deformation features, a sequence of subsurface deformation events was derived (1) matrix compaction, (2) intragranular crack formation in clasts, (3) deformation band formation in the compacted matrix, (4) tensile fracturing.

  11. Creep in Topopah Spring Member welded tuff. Yucca Mountain Site Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Martin, R.J. III; Boyd, P.J.; Noel, J.S. [New England Research, Inc., White River Junction, VT (United States); Price, R.H. [Sandia National Labs., Albuquerque, NM (United States)

    1995-06-01

    A laboratory investigation has been carried out to determine the effects of elevated temperature and stress on the creep deformation of welded tuffs recovered from Busted Butte in the vicinity of Yucca Mountain, Nevada. Water saturated specimens of tuff from thermal/mechanical unit TSw2 were tested in creep at a confining pressure of 5.0 MPa, a pore pressure of 4.5 MPa, and temperatures of 25 and 250 C. At each stress level the load was held constant for a minimum of 2.5 {times} 10{sup 5} seconds and for as long as 1.8 {times} 10{sup 6} seconds. One specimen was tested at a single stress of 80 MPa and a temperature of 250 C. The sample failed after a short time. Subsequent experiments were initiated with an initial differential stress of 50 or 60 MPa; the stress was then increased in 10 MPa increments until failure. The data showed that creep deformation occurred in the form of time-dependent axial and radial strains, particularly beyond 90% of the unconfined, quasi-static fracture strength. There was little dilatancy associated with the deformation of the welded tuff at stresses below 90% of the fracture strength. Insufficient data have been collected in this preliminary study to determine the relationship between temperature, stress, creep deformation to failure, and total failure time at a fixed creep stress.

  12. Creep in Topopah Spring Member welded tuff. Yucca Mountain Site Characterization Project

    International Nuclear Information System (INIS)

    Martin, R.J. III; Boyd, P.J.; Noel, J.S.; Price, R.H.

    1995-06-01

    A laboratory investigation has been carried out to determine the effects of elevated temperature and stress on the creep deformation of welded tuffs recovered from Busted Butte in the vicinity of Yucca Mountain, Nevada. Water saturated specimens of tuff from thermal/mechanical unit TSw2 were tested in creep at a confining pressure of 5.0 MPa, a pore pressure of 4.5 MPa, and temperatures of 25 and 250 C. At each stress level the load was held constant for a minimum of 2.5 x 10 5 seconds and for as long as 1.8 x 10 6 seconds. One specimen was tested at a single stress of 80 MPa and a temperature of 250 C. The sample failed after a short time. Subsequent experiments were initiated with an initial differential stress of 50 or 60 MPa; the stress was then increased in 10 MPa increments until failure. The data showed that creep deformation occurred in the form of time-dependent axial and radial strains, particularly beyond 90% of the unconfined, quasi-static fracture strength. There was little dilatancy associated with the deformation of the welded tuff at stresses below 90% of the fracture strength. Insufficient data have been collected in this preliminary study to determine the relationship between temperature, stress, creep deformation to failure, and total failure time at a fixed creep stress

  13. High-temperature, large-volume, lavalike ash-flow tuffs without calderas in southwestern Idaho

    Science.gov (United States)

    Ekren, E.B.; McIntyre, David H.; Bennett, Earl H.

    1984-01-01

    Rhyolitic rocks were erupted from vents in and adjacent to the Owyhee Mountains and Owyhee Plateau of southwestern Idaho from 16 m.y. ago to about 10 m.y. ago. They were deposited on a highly irregular surface developed on a variety of basement rocks that include granitic rocks of Cretaceous age, quartz latite and rhyodacite tuffs and lava flows of Eocene age, andesitic and basaltic lava flows of Oligocene age, and latitic and basaltic lava flows of early Miocene age. The rhyolitic rocks are principally welded tuffs that, regardless of their source, have one feature in common-namely internal characteristics indicating en-masse, viscous lavalike flowage. The flowage features commonly include considerable thicknesses of flow breccia at the bases of various cooling units. On the basis of the tabular nature of the rhyolitic deposits, their broad areal extents, and the local preservation of pyroclastic textures at the bases, tops, and distal ends of some of the deposits, we have concluded that the rocks were emplaced as ash flows at extremely high temperatures and that they coalesced to liquids before final emplacement and cooling. Temperatures of l090?C and higher are indicated by iron-titanium oxide compositions. Rhyolites that are about 16 m.y. old are preserved mostly in the downdropped eastern and western flanks of the Silver City Range and they are inferred to have been erupted from the Silver City Range. They rarely contain more than about 2 percent phenocrysts that consist of quartz and subequal amounts of plagioclase and alkali feldspar; commonly, they contain biotite, and they are the only rhyolitic rocks in the area to do so. The several rhyolitic units that are 14 m.y. to about 10 m.y. old contain only pyroxene-principally ferriferous and intermediate pigeonites-as mafic constituents. The rhyolites of the Silver City Range comprise many cooling units, none of which can be traced for great distances. Rocks erupted from the Owyhee Plateau include two sequences

  14. Generic repository design concepts and thermal analysis (FY11).

    Energy Technology Data Exchange (ETDEWEB)

    Howard, Robert (Oak Ridge National Laboratory, Oak Ridge, TN); Dupont, Mark (Savannah River Nuclear Solutions, Aiken, SC); Blink, James A. (Lawrence Livermore National Laboratory, Livermore, CA); Fratoni, Massimiliano (Lawrence Livermore National Laboratory, Livermore, CA); Greenberg, Harris (Lawrence Livermore National Laboratory, Livermore, CA); Carter, Joe (Savannah River Nuclear Solutions, Aiken, SC); Hardin, Ernest L.; Sutton, Mark A. (Lawrence Livermore National Laboratory, Livermore, CA)

    2011-08-01

    disposal system. Clay/shale, salt, and crystalline rock media are selected as the basis for reference mined geologic disposal concepts in this study, consistent with advanced international repository programs, and previous investigations in the U.S. The U.S. pursued deep geologic disposal programs in crystalline rock, shale, salt, and volcanic rock in the years leading up to the Nuclear Waste Policy Act, or NWPA (Rechard et al. 2011). The 1987 NWPA amendment act focused the U.S. program on unsaturated, volcanic rock at the Yucca Mountain site, culminating in the 2008 license application. Additional work on unsaturated, crystalline rock settings (e.g., volcanic tuff) is not required to support this generic study. Reference disposal concepts are selected for the media listed above and for deep borehole disposal, drawing from recent work in the U.S. and internationally. The main features of the repository concepts are discussed in Section 4.5 and summarized in Table ES-1. Temperature histories at the waste package surface and a specified distance into the host rock are calculated for combinations of waste types and reference disposal concepts, specifying waste package emplacement modes. Target maximum waste package surface temperatures are identified, enabling a sensitivity study to inform the tradeoff between the quantity of waste per disposal package, and decay storage duration, with respect to peak temperature at the waste package surface. For surface storage duration on the order of 100 years or less, waste package sizes for direct disposal of SNF are effectively limited to 4-PWR configurations (or equivalent size and output). Thermal results are summarized, along with recommendations for follow-on work including adding additional reference concepts, verification and uncertainty analysis for thermal calculations, developing descriptions of surface facilities and other system details, and cost estimation to support system-level evaluations.

  15. Generic repository design concepts and thermal analysis (FY11)

    International Nuclear Information System (INIS)

    Howard, Robert; Dupont, Mark; Blink, James A.; Fratoni, Massimiliano; Greenberg, Harris; Carter, Joe; Hardin, Ernest L.; Sutton, Mark A.

    2011-01-01

    the disposal system. Clay/shale, salt, and crystalline rock media are selected as the basis for reference mined geologic disposal concepts in this study, consistent with advanced international repository programs, and previous investigations in the U.S. The U.S. pursued deep geologic disposal programs in crystalline rock, shale, salt, and volcanic rock in the years leading up to the Nuclear Waste Policy Act, or NWPA (Rechard et al. 2011). The 1987 NWPA amendment act focused the U.S. program on unsaturated, volcanic rock at the Yucca Mountain site, culminating in the 2008 license application. Additional work on unsaturated, crystalline rock settings (e.g., volcanic tuff) is not required to support this generic study. Reference disposal concepts are selected for the media listed above and for deep borehole disposal, drawing from recent work in the U.S. and internationally. The main features of the repository concepts are discussed in Section 4.5 and summarized in Table ES-1. Temperature histories at the waste package surface and a specified distance into the host rock are calculated for combinations of waste types and reference disposal concepts, specifying waste package emplacement modes. Target maximum waste package surface temperatures are identified, enabling a sensitivity study to inform the tradeoff between the quantity of waste per disposal package, and decay storage duration, with respect to peak temperature at the waste package surface. For surface storage duration on the order of 100 years or less, waste package sizes for direct disposal of SNF are effectively limited to 4-PWR configurations (or equivalent size and output). Thermal results are summarized, along with recommendations for follow-on work including adding additional reference concepts, verification and uncertainty analysis for thermal calculations, developing descriptions of surface facilities and other system details, and cost estimation to support system-level evaluations.

  16. Underground repository for radioactive wastes

    International Nuclear Information System (INIS)

    Cassibba, R.O.

    1989-01-01

    In the feasibility study for an underground repository in Argentina, the conceptual basis for the final disposal of high activity nuclear waste was set, as well as the biosphere isolation, according to the multiple barrier concept or to the engineering barrier system. As design limit, the container shall act as an engineering barrier, granting the isolation of the radionuclides for approximately 1000 years. The container for reprocessed and vitrified wastes shall have three metallic layers: a stainless steel inner layer, an external one of a metal to be selected and a thick intermediate lead layer preselected due to its good radiological protection and corrosion resistance. Therefore, the study of the lead corrosion behaviour in simulated media of an underground repository becomes necessary. Relevant parameters of the repository system such as temperature, pressure, water flux, variation in salt concentrations and oxidants supply shall be considered. At the same time, a study is necessary on the galvanic effect of lead coupled with different candidate metals for external layer of the container in the same experimental conditions. Also temporal evaluation about the engineering barrier system efficiency is presented in this thesis. It was considered the extrapolated results of corrosion rates and literature data about the other engineering barriers. Taking into account that corrosion is of a generalized type, the integrity of the lead shall be maintained for more than 1000 years and according to temporal evaluation, the multiple barrier concept shall retard the radionuclide dispersion to the biosphere for a period of time between 10 4 and 10 6 years. (Author) [es

  17. Knowledge repositories for multiple uses

    Science.gov (United States)

    Williamson, Keith; Riddle, Patricia

    1991-01-01

    In the life cycle of a complex physical device or part, for example, the docking bay door of the Space Station, there are many uses for knowledge about the device or part. The same piece of knowledge might serve several uses. Given the quantity and complexity of the knowledge that must be stored, it is critical to maintain the knowledge in one repository, in one form. At the same time, because of quantity and complexity of knowledge that must be used in life cycle applications such as cost estimation, re-design, and diagnosis, it is critical to automate such knowledge uses. For each specific use, a knowledge base must be available and must be in a from that promotes the efficient performance of that knowledge base. However, without a single source knowledge repository, the cost of maintaining consistent knowledge between multiple knowledge bases increases dramatically; as facts and descriptions change, they must be updated in each individual knowledge base. A use-neutral representation of a hydraulic system for the F-111 aircraft was developed. The ability to derive portions of four different knowledge bases is demonstrated from this use-neutral representation: one knowledge base is for re-design of the device using a model-based reasoning problem solver; two knowledge bases, at different levels of abstraction, are for diagnosis using a model-based reasoning solver; and one knowledge base is for diagnosis using an associational reasoning problem solver. It was shown how updates issued against the single source use-neutral knowledge repository can be propagated to the underlying knowledge bases.

  18. National radioactive wasterRepository Mochovce

    International Nuclear Information System (INIS)

    2000-01-01

    In this leaflet the scheme of the Mochovce National radioactive waste repository for the Slovak Republic is presented. The National radioactive waste repository in Mochovce is a surface type storage facility. It is intended for final disposal of solid and solidified low and intermediate radioactive waste produced during the operation of nuclear power plants and institutions located within the territory of the Slovak Republic. The Repository site is situated about 2 km northwest to the Mochovce NPP

  19. The European Repository Landscape 2008 Inventory of Digital Repositories for Research Output

    CERN Document Server

    Van der Graaf, Maurits

    2009-01-01

    It is widely acknowledged that a common knowledge base for European research is necessary. Research repositories are an important innovation to the scientific information infrastructure. In 2006, digital repositories in the 27 countries of the European we

  20. Analogues to features and processes of a high-level radioactive waste repository proposed for Yucca Mountain, Nevada

    Science.gov (United States)

    Simmons, Ardyth M.; Stuckless, John S.; with a Foreword by Abraham Van Luik, U.S. Department of Energy

    2010-01-01

    Natural analogues are defined for this report as naturally occurring or anthropogenic systems in which processes similar to those expected to occur in a nuclear waste repository are thought to have taken place over time periods of decades to millennia and on spatial scales as much as tens of kilometers. Analogues provide an important temporal and spatial dimension that cannot be tested by laboratory or field-scale experiments. Analogues provide one of the multiple lines of evidence intended to increase confidence in the safe geologic disposal of high-level radioactive waste. Although the work in this report was completed specifically for Yucca Mountain, Nevada, as the proposed geologic repository for high-level radioactive waste under the U.S. Nuclear Waste Policy Act, the applicability of the science, analyses, and interpretations is not limited to a specific site. Natural and anthropogenic analogues have provided and can continue to provide value in understanding features and processes of importance across a wide variety of topics in addressing the challenges of geologic isolation of radioactive waste and also as a contribution to scientific investigations unrelated to waste disposal. Isolation of radioactive waste at a mined geologic repository would be through a combination of natural features and engineered barriers. In this report we examine analogues to many of the various components of the Yucca Mountain system, including the preservation of materials in unsaturated environments, flow of water through unsaturated volcanic tuff, seepage into repository drifts, repository drift stability, stability and alteration of waste forms and components of the engineered barrier system, and transport of radionuclides through unsaturated and saturated rock zones.

  1. Center for Leadership Development (CLD) Repository

    Data.gov (United States)

    Office of Personnel Management — The Center for Leadership Development Repository stores various data including policies, procedures, governance, guidance, security, and financial documents of the...

  2. Workshop: Creating Your Institutional Research Repository

    KAUST Repository

    Grenz, Daryl M.

    2016-11-08

    In 2002, the Scholarly Publishing and Academic Resources Coalition (SPARC) proposed the concept of an institutional repository to simultaneously disrupt and enhance the state of scholarly communications in the academic world. Thirteen years later, thousands of universities and other institutions have answered this call, but many more have not due to gaps in budgets, awareness and, most of all, practical guidance on creating an institutional repository. This workshop provides you with an essential primer on what it takes to establish a fully-functioning institutional repository. Every aspect of the process will be covered, including policies, procedures, staffing guidelines, workflows and repository technologies.

  3. Technical realization of a closure concept for a chamber-system in the underground Richard repository in the Czech Republic

    International Nuclear Information System (INIS)

    Kucerka, Miroslav

    2006-01-01

    The Phare project CZ 632.02.04 'Realization of closure of a chamber in the Richard repository as input for establishing a safety case' is a follow up implementation phase of the Phare project, CZ 01.14.03 'Solution for closure of a chamber in the Richard repository'. Main objective of both projects is to propose and realize a disposal system in selected chambers of the Richard repository, which will eliminate burden from the past practices in waste management during the first phase of the Richard repository operation (1965 - 1980) and which will improve its overall long term safety. This objective will be assured by realization of the concept of so called 'hydraulic cage', which technical solution was developed by DBE Technology within the Phare project CZ 01.14.03. The solution is described in the previous presentation 'Hydraulic Cage Concept for Waste Chambers and its Technical Implementation for the Underground Richard Repository, Litomerice, Czech Republic'. (author)

  4. A Remotely Sensed and Paleomagnetic Perspective on the Bonelli Tuff of NW AZ and SE CA

    Science.gov (United States)

    Gomez, C. D.

    2015-12-01

    The southern Black and Cerbat Mountains of NW AZ and the Sacramento Mountains of SE CA preserve ignimbrites associated with multiple episodes of volcanic activity that span at least a million years. Unraveling the stratrigraphy of these deposits, as well as their eruptive centers, is critical for constraining the volcanic history of this ignimbrite, the 18.8 Ma Peach Spring Tuff, is the recently identified 17.7 Ma Tuff of Bonelli House (TB) (Ferguson & Cook 2015) and may also occur in the southern Black and Sacramento Mountains. To help determine the extent and possible source of the TB, we have performed a combined remote sensing and paleomagnetic study of this unit, including possible correlatives. Paleomagnetic work involved Remanence and anisotropic magnetic susceptibility methods. Drill samples were collected and processed at Scripps Institute of Oceanography & Pomona College. An AC current was run to obtain the Paleomag current, as opposed to the traditional of heating up the cores at specific intervals. Sacramento Mountains samples produced an average direction of 200.9 / -26.4, which contrasts the Peach Spring Tuff paleodirection of 036.4/33 (Wells & Hillhouse, 1989). An AMS direction was determined using a MFK1 Kappabridge instrument and consistently showed similar flow direction to that of the PST. In compiling our data on a map, we took into account the Whipple Detachment Fault, ~40 km westward (Lister & Davis, 1989). We were able to identify a spectral signature and remnant paleomagnetic direction for the TB and identify potential additional outcrops in the southern Black mountains. AMS showed us that the ignimbrites originated from a source in the Silver Creek Caldera, which may indicate the PST at TB were produced from a similar source. The remnant paleomagnetic direction allows us to closely correlate these tuff units as occurring within a similar timeframe. The contrasting paleodirection of the TB and the PST allows us to confidently say that the

  5. SAPIERR Paves the way towards European regional repository

    International Nuclear Information System (INIS)

    Stefula, V.; McCombie, C.

    2004-01-01

    development to be carried out in future. High profile will be given to so-called co-operative scenario, which is most appropriate for the European context. The identification of the potential host country was deliberately excluded from the scope of SAPIERR project in this first phase. The working group participants will correspond throughout the two year duration of the study and will meet again towards the end of the project at an international seminar in Brussels in October 2005. The objective of the seminar will be to review and disseminate results of the project to a wide audience and to agree on subsequent steps on the way towards the European Regional Repository.(author)

  6. Materials Characterization Center state-of-the-art report on corrosion data pertaining to metallic barriers for nuclear-waste repositories

    Energy Technology Data Exchange (ETDEWEB)

    Merz, M.D.

    1982-10-01

    A compilation of published corrosion data on metals that have been suggested as canisters and overpack materials is presented. The data were categorized according to the solutions used in testing and divided into two parts: high-ionic strength solutions (such as seawater and brine) and low-ionic-strength waters (such as basalt and tuff waters). This distinction was made primarily because of the general difference in aggressiveness of these solutions with respect to general corrosion. A considerable amount of data indicated that titanium alloys have acceptably low uniform corrosion rates in anticipated repository sites; the other possible corrosion failure modes for titanium alloys, such as stress corrosion cracking and delayed failure due to hydrogen, have not been sufficiently studied to make any similar conclusions about lifetime with respect to these particular degradation processes. Other data suggested that iron-base alloys are sufficiently resistant to corrosion in basalt and tuff waters, although the effects of radiation and radiation combined with elevated temperature have not been reported in enough detail to conclusively qualify iron-base alloys for any particular barrier thickness in regard to uniform corrosion rate. The effect of overpack size on corrosion rate has been given little attention. A review of long-term underground data indicated that temperature and accessibility to oxygen were too different for deep geologic repositories to make the underground corrosion data directly applicable. However, the characteristics of corrosion attack, statistical treatment of data, and kinetics of corrosion showed that corrosion proceeds in a systematic and predictable way.

  7. Characteristics of potential repository wastes

    International Nuclear Information System (INIS)

    Notz, K.J.

    1989-01-01

    The Office of Civilian Radioactive Waste Management (OCRWM) is responsible for the spent fuels and other wastes that will be disposed of in a geologic repository. The two major sources of these materials are commercial light-water reactor (LWR) spent fuel and immobilized high-level waste (HLW). Other wastes that may require long-term isolation include non-LWR spent fuels and miscellaneous sources such as activated metals. Detailed characterizations are required for all of these potential repository wastes. These characterizations include physical, chemical, and radiological properties. The latter must take into account decay as a function of time. This information has been extracted from primary data sources, evaluated, and assembled in a Characteristics Data Base which provides data in four formats: hard copy standard reports, menu-driven personal computer (PC) data bases, program-level PC data bases, and mainframe computer files. The Characteristics Data Base provides a standard set of self-consistent data to the various areas of responsibility including systems integration and waste stream analysis, storage, transportation, and geologic disposal. The data will be used for design studies, evaluation of alternatives, and system optimization by OCRWM and supporting contractors. 7 refs., 5 figs., 7 tabs

  8. INIS: Nuclear Grey Literature Repository

    International Nuclear Information System (INIS)

    Savić, Dobrica

    2016-01-01

    As one of the world's largest collections of published information on the peaceful uses of nuclear science and technology, INIS represents an extraordinary example of world cooperation. Currently, as INIS members, 130 countries and 24 international organizations share and allow access to their valuable nuclear information resources, preserving them for future generations and offering a freely available nuclear knowledge repository. Since its creation in 1970, INIS has collected and provided access to more than 3.8 million bibliographic references to publications, documents, technical reports, non-copyrighted documentation, and other grey literature, as well as over a million full texts. Public interest throughout the years in accessing the INIS Collection has been remarkable. This paper deals with the challenges faced by INIS in its endeavour to increase the use, accessibility, usability and expandability of its on-line repository. It also describes document collection, the features and characteristics of implementing a new search engine, as well as the lessons learned. (author)

  9. Nuclear waste repository simulation experiments

    International Nuclear Information System (INIS)

    Rothfuchs, T.; Wieczorek, K.; Feddersen, H.K.; Staupendahl, G.; Coyle, A.J.; Kalia, H.; Eckert, J.

    1986-12-01

    This document is the third joint annual report on the Cooperative German-American 'Brine Migration Tests' that are in progress at the Asse salt mine in the Federal Republic of Germany (FRG). This Government supported mine serves as an underground test facility for research and development (R and D)-work in the field of nuclear waste repository research and simulation experiments. The tests are designed to simulate a nuclear waste repository to measure the effects of heat and gamma radiation on brine migration, salt decrepitation, disassociation of brine, and gases collected. The thermal mechanical behavior of salt, such as room closure, stresses and changes of the properties of salt are measured and compared with predicted behavior. This document covers the following sections: Issues and test objectives: This section presents issues that are investigated by the Brine Migration Test, and the test objectives derived from these issues; test site: This section describes the test site location and geology in the Asse mine; test description: A description of the test configuration, procedures, equipment, and instrumentation is given in this section; actual test chronology: The actual history of the test, in terms of the dates at which major activities occured, is presented in this section. Test results: This section presents the test results observed to data and the planned future work that is needed to complete the test; conclusions and recommendations: This section summarizes the conclusions derived to date regarding the Brine Migration Test. Additional work that would be useful to resolve the issues is discussed. (orig.)

  10. Radioactive Waste Repositories Administration - SURAO

    International Nuclear Information System (INIS)

    Kucerka, M.

    1998-01-01

    The Atomic Act specifies, among other things, responsibilities of the government in the field of safe disposal of radioactive wastes. To satisfy this responsibility, the Ministry of Industry and Trade has established the Radioactive Waste Repositories Administration (SURAO). SURAO's major responsibilities include: (a) the preparation, construction, commissioning, operation, and decommissioning of radioactive waste repositories and the monitoring of their environmental impacts; (b) radioactive waste management; (c) spent or irradiated nuclear fuel processing into a form suitable for storage/disposal or reuse; (d) record-keeping of received radioactive wastes and their producers; (e) administration of fund transfers as stipulated by the Atomic Act, Article 27; (f) development of proposals for specification of fees to be paid to the Nuclear Account; (g) responsibility for and coordination of research and development in the field of radioactive waste handling and management; (h) supervision of licensees' margin earmarked for the decommissioning of their facilities; (i) providing services in radioactive waste handling and management; (j) handling and management of radioactive wastes that have been transferred to the Czech Republic from abroad and cannot be sent back; (k) interim administration of radioactive wastes that have become state property. The Statute of the Administration is reproduced in full. (P.A.)

  11. Viability Assessment of a Repository at Yucca Mountain. Volume 5: Costs to Construct and Operate the Repository

    Energy Technology Data Exchange (ETDEWEB)

    None

    1998-12-01

    This volume presents a management summary of the cost estimate to complete the design, and to license, construct, operate, monitor, close, and decommission a Monitored Geologic Repository at Yucca Mountain in Nevada. This volume summarizes the scope, estimating methodologies, and assumptions used in development of the Monitored Geologic Repository-VA cost estimate. It identifies the key features necessary to understand the summary costs presented herein. This cost summary derives from a larger body of documented cost analysis. Volume 5 is organized to reflect this structured approach to cost estimation and contains the following sections: Section 1, Cost Elements. This section briefly defines the components of each major repository cost element. Section 2, Project Phases. This section presents the definition, as used in the estimate, of five project phases (Licensing, Pre-emplacement Construction, Emplacement Operations, Monitoring, and Closure and Decommissioning) and the schedule dates for each phase. It also contains major milestone dates and a bar chart schedule. Section 3, Major Assumptions. This section identifies key high-level assumptions for the cost estimate basis. Additional detailed assumptions are included in the appendices. Section 4, Integrated Cost Summary. This section presents a high-level roll-up of the VA costs resulting from the estimating work. The tables and figures contained in this section were compiled from the more detailed cost estimates in the appendices. Section 5, References. This section identifies the references that support this cost volume. Appendices. For each major repository cost element, Appendices B-F [B, C, D, E, F] presents additional information on the scope of cost elements, identifies methodologies used to develop the cost estimates, lists underlying cost assumptions, and tabulates summary results. Appendix A contains a glossary to assist the reader in understanding the terminology in Volume 5. Appendix G presents costs

  12. Stonewall Mountain Volcanic Center, southern Nevada: Stratigraphic, structural, and facies relations of outflow sheets, near-vent tuffs, and intracaldera units

    Science.gov (United States)

    Weiss, Steven I.; Noble, Donald C.

    1989-05-01

    Directly south and southeast of Stonewall Mountain, Nevada, a depression and north facing caldera scarp were formed during and(or) after eruption of the Spearhead Member of the late Miocene Stonewall Flat Tuff. Abundant large lithic and juvenile blocks are present in the Spearhead Member within 0.5 km of this topographic margin but absent elsewhere in the ash-flow sheet, consistent with eruption from vents in the Stonewall Mountain area. Within about 100,000 years, comendite tuff of the overlying Civet Cat Canyon Member of the Stonewall Flat Tuff buried the depression and associated scarp. The Civet Cat Canyon Member is traceable continuously to the north from an outflow sheet capping northwestern Pahute Mesa, into near-vent tuff on the southeastern flank of Stonewall Mountain. Proximal outflow-sheet tuff locally exhibits strong rheomorphic disruption and is overlain without a cooling break by surge, flow, and fall deposits of trachytic composition. Much of Stonewall Mountain is composed of welded tuff and megabreccia interpreted as intracaldera tuff of the Civet Cat Canyon Member, strongly suggesting that the vent area of the member was largely within Stonewall Mountain. Welded tuff of trachytic composition comprises an important part of the intracaldera Civet Cat Canyon Member, which was intruded by dikes and plugs of trachyte and rhyolite. Juvenile inclusions of basalt dispersed in near-vent facies trachyte tuff provide direct evidence for the high-level involvement of basaltic magma in the evolution of the highly potassic Stonewall Mountain center. Complex discordant compaction foliations and the widespread presence of megabreccia within the intracaldera tuff suggest, following Foley (1978), cauldron subsidence by piecemeal collapse during eruption of the Civet Cat Canyon Member. The elevation of intracaldera tuff and intrusions in Stonewall Mountain above the surrounding ashflow sheet suggests a significant amount of magmatic uplift, perhaps involving the

  13. Nuclear waste repository research at the micro- to nanoscale

    Science.gov (United States)

    Schäfer, T.; Denecke, M. A.

    2010-04-01

    Micro- and nano-focused synchrotron radiation techniques to investigate determinant processes in contaminant transport in geological media are becoming especially an increasingly used tool in nuclear waste disposal research. There are a number of reasons for this but primarily they are driven by the need to characterize actinide speciation localized in components of heterogeneous natural systems. We summarize some of the recent research conducted by researchers of the Institute of Nuclear Waste Disposal (INE) at the Karlsruhe Institute of Technology using micro- and nano-focused X-ray beams for characterization of colloids and their interaction with minerals and of elemental and phase distributions in potential repository host rocks and actinide speciation in a repository natural analogues sample. Such investigations are prerequisite to ensuring reliable assessment of the long term radiological safety for proposed nuclear waste disposal sites.

  14. Electronic Repository of Russian Historical Statistics

    NARCIS (Netherlands)

    Tykhonov, Vyacheslav; Kessler, Gijs; Markevich, Andrei; de Vries, Jerry

    2014-01-01

    The Electronic Repository for Russian Historical Statistics brings together data extracted from various published and unpublished sources in one place. Its principal focus is Russian economic and social history of the last three centuries (18th-21st). The repository caters to the needs of the

  15. Towards Content Development For Institutional Digital Repository ...

    African Journals Online (AJOL)

    The growth in Information and Communication Technology has lead to the emergence of Institutional Digital Repository, a digital archive for the preservation and dissemination of institutional research outputs. Institutional Digital Repositories make possible global dissemination of research outputs through the use of the ...

  16. Analisis Konten dan Kebijakan Akses Institutional Repository

    Directory of Open Access Journals (Sweden)

    Amirul Ulum

    2016-07-01

    Abstract; Institutional repository has become a major concern of higher education in Indonesia. The number of institutional respository was increased, one of the reason is the ranking web of repositories has been conducted by the Cybermetrics Lab in 2008. At that time, many institutions started to build institutional repository in order to manage the scientific work and also trying to reach the better ranks. Meanwhile, it is an achievement of institution performance which can be promote and increase visibility for the institution. University of Surabaya has also developed the institutional repository and managed by the library. The aims of this study is to analyze the content availability and access policies defined by the University of Surabaya repository  providing services to the academic community and external users. The method used in this study by using observations of the institutional repository University of Surabaya with a literature review to clarify the analysis of the content and access policies. The results of this study indicate that the library's role is has the authority to manage the scientific work of academic community can be done through the institutional repository. However there is still need for library to be proactive to communicate regulations on mandatory deposit of scientific work and create intensive promotion of the institutional repository.

  17. Asset Reuse of Images from a Repository

    Science.gov (United States)

    Herman, Deirdre

    2014-01-01

    According to Markus's theory of reuse, when digital repositories are deployed to collect and distribute organizational assets, they supposedly help ensure accountability, extend information exchange, and improve productivity. Such repositories require a large investment due to the continuing costs of hardware, software, user licenses, training,…

  18. Decompression of magma into repository tunnels

    NARCIS (Netherlands)

    Bokhove, Onno; Woods, A.W.

    2002-01-01

    It is nontrivial to find and design safe repository sites for nuclear waste. It appears common sense to drill tunnels as repository sites in a mountain in remote and relatively dry regions. However, erosion of the waste canisters by naturally abundant chemicals in the mountains water cycle remains a

  19. Types of Online Hierarchical Repository Structures

    Science.gov (United States)

    Hershkovitz, Arnon; Azran, Ronit; Hardof-Jaffe, Sharon; Nachmias, Rafi

    2011-01-01

    This study presents an empirical investigation of online hierarchical repositories of items presented to university students in Web-supported course websites, using Web mining methods. To this end, data from 1747 courses were collected, and the use of online repositories of content items in these courses was examined. At a later stage, courses…

  20. ORBi – Open Repository and Bibliography

    Czech Academy of Sciences Publication Activity Database

    Burešová, Iva; Doleželová, Jana; Lhoták, Martin

    -, 1-2 (2011) E-ISSN 1805-2800 Institutional research plan: CEZ:AV0Z70830501 Keywords : repository * open access * ORBi * University of Liege http://www.lib.cas.cz/casopis-informace/orbi-%E2%80%93-open- repository -and-bibliography/

  1. On conditions and parameters important to model sensitivity for unsaturated flow through layered, fractured tuff; Results of analyses for HYDROCOIN [Hydrologic Code Intercomparison Project] Level 3 Case 2: Yucca Mountain Project

    Energy Technology Data Exchange (ETDEWEB)

    Prindle, R.W.; Hopkins, P.L.

    1990-10-01

    The Hydrologic Code Intercomparison Project (HYDROCOIN) was formed to evaluate hydrogeologic models and computer codes and their use in performance assessment for high-level radioactive-waste repositories. This report describes the results of a study for HYDROCOIN of model sensitivity for isothermal, unsaturated flow through layered, fractured tuffs. We investigated both the types of flow behavior that dominate the performance measures and the conditions and model parameters that control flow behavior. We also examined the effect of different conceptual models and modeling approaches on our understanding of system behavior. The analyses included single- and multiple-parameter variations about base cases in one-dimensional steady and transient flow and in two-dimensional steady flow. The flow behavior is complex even for the highly simplified and constrained system modeled here. The response of the performance measures is both nonlinear and nonmonotonic. System behavior is dominated by abrupt transitions from matrix to fracture flow and by lateral diversion of flow. The observed behaviors are strongly influenced by the imposed boundary conditions and model constraints. Applied flux plays a critical role in determining the flow type but interacts strongly with the composite-conductivity curves of individual hydrologic units and with the stratigraphy. One-dimensional modeling yields conservative estimates of distributions of groundwater travel time only under very limited conditions. This study demonstrates that it is wrong to equate the shortest possible water-travel path with the fastest path from the repository to the water table. 20 refs., 234 figs., 10 tabs.

  2. Abadia de Goias repository: design conception; Repositorio de Abadia de Goias: concepcao de projeto

    Energy Technology Data Exchange (ETDEWEB)

    Martin Alves, Antonio Sergio de; Santos, Cicero Durval Pacifici dos; Passos, Erivaldo Mario dos; Coutinho, Fernando Paulo Millen [NUCLEN, Rio de Janeiro, RJ (Brazil)

    1995-12-31

    In this paper have been presented the criteria, the methodologies and the parameters that were utilized for the design of Abadia de Goias Repository. Hereby the purpose is to show in a succinct way the know how that has been acquired for the design of a LLW and ILW repository. This paper presents information and details concerning to the various phases of the design, beginning with the data collecting activity, the safety analysis elaboration up to the definition of the final concept of the repository and of the required infrastructure work. The safety analysis, based on the Cs-137 migration through the groundwater, made possible at first to determine the places of the repository site where the population is not allowed to drill wells. The analysis allowed also the institutional control period calculation based on the maximum concentration of Cs-137 in the aquifer as well as in the intrusion models. (author). 16 refs., 3 figs., 1 tab.

  3. Building didactic content repositories: method and tools

    Directory of Open Access Journals (Sweden)

    Jacek Marciniak

    2012-12-01

    Full Text Available The article presents the method and tools which allows to build repositories of didactic materials in SCORM using UCTS taxonomic system and Content Repository software. SCORM is a universal specification designed to create reusable materials in digital format. UCTS is a taxonomic model which allows to attribute didactic interpretations to content components. Content Repository is a web software designed to create, store and process didactic content in SCORM. The method was verified while creating E-archeology Content Repository which stores e-learning materials on protection and management of archeological heritage. The repository contains approximately 4500 Learning Objects in 5 languages and about 800 components of didactically useful e-learning components described in UCTS.

  4. Expected repository environments in granite: thermal environment

    International Nuclear Information System (INIS)

    Osnes, J.D.; Coates, G.K.; DeJong, K.B.; Loken, M.C.; Wagner, R.A.

    1984-10-01

    This report was prepared for the Reference Repository Conditions - Interface Working Group and will be used to formulate a standardized description of repository conditions for use by the Civilian Radioactive Waste Management Program. A baseline repository in granite is defined and three waste types are considered: unreprocessed spent fuel, commercial high-level waste, and defense high-level waste. Three different scales of repository environment are described - the very-near field (near the waste canister), the near field (the room and pillar), and the far field (the entire repository and surroundings). Information was compiled from the literature and, in addition, a number of calculations were performed. The major emphasis is on describing the thermal environment although the ground-water flow and chemical and radiation environments are also described. 61 figures, 24 tables

  5. An Interactive Map for Showcasing Repository Impacts

    Directory of Open Access Journals (Sweden)

    Hui Zhang

    2017-04-01

    Full Text Available Digital repository managers rely on usage metrics such as the number of downloads to demonstrate research visibility and impacts of the repositories. Increasingly, they find that current tools such as spreadsheets and charts are ineffective for revealing important elements of usage, including reader locations, and for attracting the targeted audiences. This article describes the design and development of a readership map that provides an interactive, near-real-time visualization of actual visits to an institutional repository using data from Google Analytics. The readership map exhibits the global impacts of a repository by displaying the city of every view or download together with the title of the scholarship being read and a hyperlink to its page in the repository. We will discuss project motivation and development issues such as authentication with Google API, metadata integration, performance tuning, and data privacy.

  6. EEI/UWASTE oversight of the DOE Repository Program by the Repository Information Exchange Team

    International Nuclear Information System (INIS)

    Henkel, C.J.; Supko, E.M.; Schwartz, M.H.

    1993-01-01

    The Utility Nuclear Waste and Transportation Program of the Edison Electric Institute (EEI/UWASTE) has conducted reviews of the US DOE's repository program through its Repository Information Exchange Team (RIET or Team). Eight such reviews have been conducted since 1985 covering topics that include repository program management and control; repository schedule; repository budget; quality assurance; site characterization; repository licensing; environmental issues; and institutional and public information activities. The utility industry has used these repository program reviews as a forum for providing DOE's Office of Civilian Radioactive Waste Management (OCRWM) with comments on the direction of the repository program, advice for future actions regarding quality assurance activities and repository licensing, and suggestions for management and control of the Repository Program. The most significant recommendations made by the utility industry through the RIET are discussed along with any subsequent action by OCRWM in response to or subsequent to utility industry recommendations. The process used by the RIET to develop its recommendations to OCRWM regarding the repository program is also discussed

  7. A global nuclear waste repository

    Science.gov (United States)

    Lin, Wunan

    As a concerned scientist, I think that having a global nuclear waste repository is a reachable goal for human beings. Maybe through this common goal, mankind can begin to treat each other as brothers and sisters. So far, most human activities are framed by national boundaries, which are purely arbitrary. Breaking through these national boundaries will be very beneficial to human beings.Formation of the International Geosphere-Biosphere Program in 1986 indicates a growing awareness on the part of scientists regarding Earth as a system. The Apollo missions gave us a chance to look back at Earth from space. That perspective emphasized that our Earth is just one system: our only home. It is in deed a lonely boat in the high sea of dark space. We must take good care of our “boat.”

  8. Characteristics of potential repository wastes

    International Nuclear Information System (INIS)

    Cowart, C.G.; Notz, K.J.

    1992-10-01

    This report presents the results of a fully documented peer review of DOE/RW-0184, Rev. 1, ''Characteristics of Potential Repository Wastes''. The peer review was chaired and administered by oak Ridge National Laboratory (ORNL) for the Department of Energy (DOE), Office of Civilian Radioactive Waste Management (OCRWM) and was conducted in accordance with OCRWM QA procedure QAAP 3.3 ''Peer Review'' for the purpose of quailing the document for use in OCRWM quality-affecting work. The peer reviewers selected represent a wide range of experience and knowledge particularly suitable for evaluating the subject matter. A total of 596 formal comments were documented by the seven peer review panels, and all were successfully resolved. The peers reached the conclusion that DOE/RW-0184, Rev. 1, is quality determined and suitable for use in quality-affecting work

  9. Modern Project: monitoring developments for safe repository operation and staged closure

    International Nuclear Information System (INIS)

    Mayer, S.; Ouchhi, S.; Verstricht, J.; Maurer, H.; Breen, B.

    2010-01-01

    Document available in extended abstract form only. In a first part, the overall objectives of the MoDeRn project (Monitoring Developments for safe Repository operation and stage closure project) are presented. MoDeRn is a four year (2009-2013) collaborative project co-funded under the 7. Framework Program for Nuclear Research and Training (EURATOM). It involves 17 organizations responsible for research into radioactive waste management in the European Union, United States, Japan and Switzerland, with partners with extensive experience in monitoring activities in underground research laboratories (URL); as well as research institutes and universities with substantial experience in research on socio-technical interactions and public and stakeholder engagement. An overview of the project work packages and of their interdependencies is given. The successful implementation of a repository program for radioactive waste relies on both the technical aspects of a sound safety strategy and scientific and engineering excellence as well as on social aspects such as stakeholder acceptance and confidence. Monitoring is considered key in serving both technical and social objectives. It is not only essential to underpin the technical safety strategy and quality of the engineering, but it can also be an important tool for public communication, contributing to public understanding of and confidence in the repository behaviour. By inclusion of specific national contexts of waste management programs in different countries, the MoDeRn project aims at providing a reference framework for development and implementation of monitoring activities. This will be achieved by stakeholder engagement during all identifiable phases of the radioactive waste disposal process. Thus, site characterisation, construction, operation and staged closure, as well as post-closure institutional control phases have to be addressed. MoDeRn considers different host rock types, such as salt, tuff, crystalline rock

  10. The European Repository Landscape : Inventory study into present type and level of OAI compliant Digital Repository activities in the EU

    NARCIS (Netherlands)

    Graaf, van der Maurits; Eijndhoven, van Kwame

    2008-01-01

    Repositories hebben de laatste jaren een sterke ontwikkeling doorgemaakt; steeds meer universiteiten, onderzoeksinstituten en hbo-instellingen plaatsen hun kennis en resultaten in 'repositories' zodat deze via internet vrij toegankelijk zijn. In deze studie wordt het Europese repository landschap in

  11. Estimation of possibilities of making euro pallets from reclaimed polyolefin’s with tuff

    Directory of Open Access Journals (Sweden)

    S. Kuciel

    2010-07-01

    Full Text Available Possibilities of reusing and developing of waste plastics are one of the main problems of waste management for municipal governmentespecially in the context of adapting Polish law to standards of EC [1]. During the last 10 years total amount of plastics waste increasedtwice, especially in communal agglomerations. Among communal waste plastics make up 7 to 14% of whole their mass and 30% of theirvolume [1,2]. Plastic products have been recycled to be used in a number of different products often different from their original use.Reclaimed plastics can’t be used as products which have contact with food or as high demands esthetic and hygienic products, they alsoshouldn’t be applied as short-time used products because they quickly come back to plastics store-place. Reclaimed plastics have lowerproperties than virgin plastics – mainly the strength falls with the simultaneous fall of modules and increase fragile especially for PP, PE,PS and PET [1]. One of the possibilities of reinforcement of polyolefines is adding diverse fillers like glass or carbon fibers (but they arerather expensive and natural fillers like mineral, wood and others [3]. It’s especially important for wasted of low density polyethylenewhich has low modulus. For the tests it was used waste polyethylene (LDPE and HDPE from industrial with 15% mineral fillers – tuff.For the tests it was prepared two kinds of composites materials with 15% of tuff powder. Besides for comparison it was tested recycledpolyethylene (HDPE and LDPE and next was tested specimens cut out from produced europallets (with 15% of tuff. It was testedmechanical properties all prepared composite materials like tensile strength, stress and bending e-modulus and processing properties likemelt flow, Vicat point and photos on SEM microscope.

  12. The Bishop Tuff giant magma body: An alternative to the Standard Model

    Science.gov (United States)

    Gualda, G. A.; Ghiorso, M. S.

    2012-12-01

    The Bishop Tuff (California), which erupted at 760 ka and formed the Long Valley caldera, is the archetypical example of a thermally and compositionally stably stratified giant magma body. The deposit includes only high-silica rhyolite, but it is zoned with an early-erupted, pyroxene-free, crystal-poor (5-20 wt. % crystals) lower unit (EBT) and a late-erupted, pyroxene-bearing, more crystal-rich (5-30 wt. % crystals) upper unit (LBT). Gradients in composition and temperature within the magma body were first inferred by Hildreth (1979): Fe-Ti oxide thermometry reveals a gradient in pre-eruptive temperatures from EBT to LBT, suggesting thermal stratification; and the homogeneity of phenocryst compositions within each pumice clast suggests stable compositional stratification. This view of the Bishop magma body - the Standard Model - has remained largely unchallenged by subsequent work; we present new pre-eruptive temperature (T) and pressure (P) estimates to critically assess its viability. The pinnacle of the Standard Model is the gradient in pre-eruptive T and fO2 inferred from Fe-Ti oxides. Fe-Ti oxides also constrain TiO2 activity in the melt (Ghiorso & Gualda, CMP, in press); the positive correlation between T and aTiO2 observed in the Bishop dataset cannot be explained by magmatic crystallization, and comparison with aTiO2 from rhyolite-MELTS shows that Fe-Ti oxides were not in equilibrium with melt and do not record pre-eruptive conditions. We use zircon saturation temperatures calculated with literature glass inclusion data (Wallace et al., JGR, 1999; Anderson et al., JPet, 2000) to assess pre-eruptive temperatures; Zr contents in glass inclusions vary over a narrow interval (~70-110 ppm) for both EBT and LBT, yielding T between 720 and 755 °C for both, arguing against the inferred thermal stratification. Geobarometry should yield systematic differences between EBT and LBT. Published H2O-CO2 glass inclusion data yield overlapping P for EBT and LBT pumice

  13. Experimental Analyses of Yellow Tuff Spandrels of Post-medieval Buildings in the Naples Area

    International Nuclear Information System (INIS)

    Calderoni, B.; Cordasco, E. A.; Lenza, P.; Guerriero, L.

    2008-01-01

    Experimental analyses have been carried out on tuff masonry specimens in order to investigate the structural behaviour of historical buildings in the Naples area (Southern Italy). Spandrels of post-medieval buildings (late XVI to early XX century) have been analysed, with emphasis on morphological characteristics according to chronological indicators. Results of the experimentation on scaled models (1:10) are discussed and the better behaviour of historical masonry typologies on respect to the modern one is highlighted. Comparison with theoretical formulations of ultimate shear resistance are provided too

  14. Criticality characteristics of mixtures of plutonium, silicon dioxide, Nevada tuff, and water

    International Nuclear Information System (INIS)

    Sanchez, R.; Myers, W.; Hayes, D.

    1997-01-01

    The nuclear criticality characteristics of mixtures of plutonium, silicon dioxide, and water (Part A) or plutonium, silicon dioxide, Nevada Yucca Mountain tuff, and water (Part B) have become of interest because of the appearance of recent papers on the subject. These papers postulate that if excess weapons plutonium is vitrified into a silicate log and buried underground, a self-sustaining neutron chain reaction may develop given sufficient time and interaction with the burial medium. Moreover, given specific geologic actions resulting in postulated configurations, the referenced papers state that nuclear explosions could occur with multi-kiloton yields or yields equivalent to hundreds of tons of TNT

  15. Experimental research on sealing of boreholes, shafts and ramps in welded tuff

    International Nuclear Information System (INIS)

    Fuenkajorn, K.

    1996-01-01

    Laboratory and in-situ experiments have been conducted to determine the mechanical and hydraulic performance of cement borehole seals in densely welded Apache Leap tuff. Test results indicate that under saturated conditions, commercial expansive cement can provide good bond strength and adequate hydraulic performance for borehole seal under changing stress conditions. The cement seal should be installed at the intact portion of the opening, and should have a length-to-diameter ratio greater than four. Drying increases borehole plug permeability and decreases mechanical and hydraulic bonds at the plug-rock interface. In-situ testing indicates that installation procedure may significantly affect the cement plug performance

  16. USGS studies of physical--chemical relationships in salt repositories

    International Nuclear Information System (INIS)

    Stewart, D.B.

    1977-01-01

    The amount and physical properties of brine that can occur in salt repositories at elevated temperatures and pressures adjacent to waste-bearing cannisters will have considerable impact on the mechanical strength and stability of the repository. Brine will form readily from H 2 O absorbed on surfaces, diffusion along grain boundaries, movement of fluid inclusions, dehydration of hydrous minerals such as gypsum, polyhalite or clays, or even from leakage through failed shaft openings. A T-P diagram for NaCl--H 2 O shows the limits for coexisting solid-liquid-gas assemblages in salt repositories. Isobaric T-X diagrams are included to show compositional details at pressures below the critical point and above it. Properties of the fluid phases such as volume, density, heat capacity, enthalpy, viscosity, surface tension, osmotic coefficients, etc. can be well described (>0.01% to 2 O. Because aggregates of solids are mechanically weakened by interstitial liquid, determination of mechanical properties of brine-bearing aggregates is needed. A maximum of one third by weight of brine (not H 2 O), and probably much less, will destroy rock strength

  17. Pore-water extraction from unsaturated tuff by triaxial and one-dimensional compression methods, Nevada Test Site, Nevada

    Science.gov (United States)

    Mower, Timothy E.; Higgins, Jerry D.; Yang, In C.; Peters, Charles A.

    1994-01-01

    Study of the hydrologic system at Yucca Mountain, Nevada, requires the extraction of pore-water samples from welded and nonwelded, unsaturated tuffs. Two compression methods (triaxial compression and one-dimensional compression) were examined to develop a repeatable extraction technique and to investigate the effects of the extraction method on the original pore-fluid composition. A commercially available triaxial cell was modified to collect pore water expelled from tuff cores. The triaxial cell applied a maximum axial stress of 193 MPa and a maximum confining stress of 68 MPa. Results obtained from triaxial compression testing indicated that pore-water samples could be obtained from nonwelded tuff cores that had initial moisture contents as small as 13 percent (by weight of dry soil). Injection of nitrogen gas while the test core was held at the maximum axial stress caused expulsion of additional pore water and reduced the required initial moisture content from 13 to 11 percent. Experimental calculations, together with experience gained from testing moderately welded tuff cores, indicated that the triaxial cell used in this study could not apply adequate axial or confining stress to expel pore water from cores of densely welded tuffs. This concern led to the design, fabrication, and testing of a one-dimensional compression cell. The one-dimensional compression cell used in this study was constructed from hardened 4340-alloy and nickel-alloy steels and could apply a maximum axial stress of 552 MPa. The major components of the device include a corpus ring and sample sleeve to confine the sample, a piston and base platen to apply axial load, and drainage plates to transmit expelled water from the test core out of the cell. One-dimensional compression extracted pore water from nonwelded tuff cores that had initial moisture contents as small as 7.6 percent; pore water was expelled from densely welded tuff cores that had initial moisture contents as small as 7

  18. LABORATORY EXPERIMENTS ON HEAT-DRIVEN TWO-PHASE FLOWS IN NATURAL AND ARTIFICIAL ROCK FRACTURES

    International Nuclear Information System (INIS)

    TIMOTHY J. KNEAFSEY AND KARSTEN PRUESS

    1998-01-01

    Water flow in partially saturated fractures under thermal drive may lead to fast flow along preferential localized pathways and heat pipe conditions. At the potential high-level nuclear waste repository at Yucca Mountain, water flowing in fast pathways may ultimately contact waste packages and transport radionuclides to the accessible environment. Sixteen experiments were conducted to visualize heat-driven liquid flow in fracture models that included (1) assemblies of roughened glass plates, (2) epoxy replicas of rock fractures, and (3) a fractured specimen of Topopah Spring tuff. Continuous rivulet flow was observed for high liquid flow rates, intermittent rivulet flow and drop flow for intermediate flow rates, and film flow for lower flow rates and wide apertures. Heat pipe conditions (vapor-liquid counterflow with phase change) were identified in five of the seven experiments in which spatially resolved thermal monitoring was performed, but not when liquid-vapor counterflow was hindered by very narrow apertures, and when inadequate working fluid volume was used

  19. Laboratory experiments on heat-drive two-phase flows in natural and artificial rock fractures

    International Nuclear Information System (INIS)

    Kneafsey, Timothy J.; Pruess, Karsten

    1998-01-01

    Water flow in partially saturated fractures under thermal drive may lead to fast flow along preferential localized pathways and heat pipe conditions. At the potential high-level nuclear waste repository at Yucca Mountain, water flowing in fast pathways may ultimately contact waste packages and transport radionuclides to the accessible environment. Sixteen experiments were conducted to visualize heat-driven liquid flow in fracture models that included (1) assemblies of roughened glass plates, (2) epoxy replicas of rock fractures, and (3) a fractured specimen of Topopah Spring tuff. Continuous rivulet flow was observed for high liquid flow rates, intermittent rivulet flow and drop flow for intermediate flow rates, and film flow for lower flow rates and wide apertures. Heat pipe conditions (vapor-liquid counterflow with phase change) were identified in five of the seven experiments in which spatially resolved thermal monitoring was performed but not when vapor-liquid counterflow was hindered by very narrow apertures and when an inadequate working fluid volume was used

  20. Transport of Radon Gas into a Tunnel at Yucca Mountain-Estimating Large-Scale Fractured Tuff Hydraulic Properties and Implications for the Operation of the Ventilation System

    International Nuclear Information System (INIS)

    Unger, A.; Finsterle, S.; Bodvarsson, G.

    2003-01-01

    Radon gas concentrations have been monitored as part of the operation of a tunnel (the Exploratory Studies Facility-ESF) at Yucca Mountain to ensure worker safety. The objective of this study was to examine the potential use of the radon data to estimate large-scale formation properties of fractured tuffs. This objective was examined by developing a numerical model, based upon the characteristics of the ESF and the Topopah Spring welded (TSw) tuff unit, capable of predicting radon concentrations for prescribed ventilation conditions. The model was used to address two specific issues. First, it was used to estimate the permeability and porosity of the fractures in the TSw at the length scale of the ESF and extending tens of meters into the TSw, which surrounds the ESF. Second, the model was used to understand the mechanism leading to radon concentrations exceeding a specified level within the ESF. The mechanism controlling radon concentrations in the ESF is a function of atmospheric barometric fluctuations being propagated down the ESF along with ventilated air flow and the slight suction induced by the ventilation exhaust fans at the South Portal of the ESF. These pressure fluctuations are dampened in the TSw fracture continuum according to its permeability and porosity. Consequently, as the barometric pressure in the ESF drops rapidly, formation gases from the TSw are pulled into the ESF, resulting in an increase in radon concentrations. Model calibration to both radon concentrations measured in the ESF and gas-phase pressure fluctuations in the TSw yielded concurrent estimates of TSw fracture permeability and porosity of l x 10 -11 m 2 and 0.00034, respectively. The calibrated model was then used as a design tool to predict the effect of adjusting the current ventilation-system operation strategy for reducing the probability of radon gas concentrations exceeding a specified level

  1. Sorption-desorption studies on tuff III. A continuation of studies with samples from Jackass Flats and Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Wolfsberg, K.; Aguilar, R.D.; Bayhurst, B.P.

    1981-05-01

    This report is the third in a series of reports describing studies of sorption and migration of radionuclides in tuff. The investigations were extended to lithologies of tuff not previously studied. Continuing experiments with uranium, plutonium, and americium are described. The dependence of sorption on the concentration of the sorbing element and on the solution-to-solid ratio was investigated for a number of nuclides and two lithologies. A circulating system was designed for measuring sorption ratios. Values obtained from this system, batch measurements, and column elutions are compared. Progress on measuring and controlling Eh is described

  2. Andra's geologic repository monitoring strategy

    International Nuclear Information System (INIS)

    Buschaert, S.; Lesoille, S.; Bertrand, J.; Landais, P.

    2012-01-01

    Document available in extended abstract form only. After having concluded a feasibility study of deep geological disposal for high-level and long-lived radioactive waste in 2005, Andra was charged by the Planning Act no. 2006-739 to design and create an industrial site for geological disposal called Cigeo which must be reversible for at least a century-long period. The French Safety Guide recommends that Andra develop a monitoring program to be implemented at repository construction and conducted until closure, and possibly after closure, with the aim to confirming prior expectations and enhancing knowledge of relevant processes. This abstract focuses on underground structure monitoring. The monitoring system is based on a combination of in-situ instrumentation and nondestructive methods to obtain the required level of reliable performance. To optimize the device distribution, we take into account both the repetitive design of disposal cells and the homogeneity of the rock properties. This resulted in distinguishing pilot disposal cells that are highly instrumented and standard disposal cells where the instrumentation density could be reduced; monitoring will rely mostly on robotic nondestructive evaluations. If monitoring technologies do not comply with all monitoring objectives, real withdrawal tests of high level wastes in some pilot disposal cells are also planned to provide the possibility of carrying out visual inspection, destructive analyses and samplings on construction materials. Such cells are planned to be dismantled because of the potential disturbance of their component performances from the testing process. Based on this overall strategy, Andra has analyzed the technical requirements that must be met by its monitoring equipment. First, these must be able to provide information on key THMCR (Thermal- Hydraulic-Mechanical-Chemical and Radiological) processes, to provide a three-dimensional image of a disposal component's behavior and thus to understand

  3. Building the repositories to serve

    International Nuclear Information System (INIS)

    Lersch, D.

    1993-04-01

    The project to design and build the Superconducting Super Collider (SSC) Laboratory also includes the exciting opportunity to implement client/server information systems. Lab technologists were eager to take advantage of the cost savings inherent in the open systems and a distributed, client server environment and, at the same time, conscious of the need to provide secure repositories for sensitive data as well as a schedule sensitive acquisition strategy for mission critical software. During the first year of project activity, micro-based project management and business support systems were acquired and implemented to support a small study project of less than 400 people allocating contracts of less than $1 million. The transition to modern business systems capable of supporting more than 10,000 participants (world wide) who would be researching and developing the new technologies that would support the world's largest scientific instrument, a 42 Tevatron, superconducting, super collider became a mission critical event. This paper will present the SSC Laboratory's strategy to balance our commitment to open systems, structured query language (SQL) standards and our success with acquiring commercial off the shelf software (COTS) to support our immediate goals. Included will be an outline of the vital roles played by other labs (Livermore, CERN, Brookhaven, Fermi and others) and a discussion of future collaboration potentials to leverage the information activities of all Department of Energy (DOE) funded labs

  4. Characteristics of potential repository wastes

    International Nuclear Information System (INIS)

    1992-07-01

    The LWR spent fuels discussed in Volume 1 of this report comprise about 99% of all domestic non-reprocessed spent fuel. In this report we discuss other types of spent fuels which, although small in relative quantity, consist of a number of diverse types, sizes, and compositions. Many of these fuels are candidates for repository disposal. Some non-LWR spent fuels are currently reprocessed or are scheduled for reprocessing in DOE facilities at the Savannah River Site, Hanford Site, and the Idaho National Engineering Laboratory. It appears likely that the reprocessing of fuels that have been reprocessed in the past will continue and that the resulting high-level wastes will become part of defense HLW. However, it is not entirely clear in some cases whether a given fuel will be reprocessed, especially in cases where pretreatment may be needed before reprocessing, or where the enrichment is not high enough to make reprocessing attractive. Some fuels may be canistered, while others may require special means of disposal. The major categories covered in this chapter include HTGR spent fuel from the Fort St. Vrain and Peach Bottom-1 reactors, research and test reactor fuels, and miscellaneous fuels, and wastes generated from the decommissioning of facilities

  5. Economics of mined geologic repositories

    International Nuclear Information System (INIS)

    Hofmann, P.L.; Dippold, D.G.

    1983-01-01

    During 1982, Congress considered legislation to provide for the development of repositories for the disposal of high-level radioactive waste and spent nuclear fuel. The result of this legislative effort was the Nuclear Waste Policy Act of 1982 (NWPA), PL 97-425, signed into law January 7, 1983. An important part of the NWPA was the establishment of special funds in the US Treasury for Waste Disposal and Interim Storage to be financed by user fees to pay for all costs of the program. An initial fee of 1.0 mill per kilowatt-hour was specified. The Secretary was asked to annually review the amount of the fees established... to evaluate whether collection of the fee will provide sufficient revenues to offset the costs... In the event of a prospective fee cost mismatch, the Secretary was asked to propose an adjustment to the fee to insure full cost recovery. A series of studies were sponsored by DOE in 1982 to estimate program costs, to calculate the necessary fees to assure cost recovery, and to address uncertainties that could affect future program costs and consequent fee schedules. A brief summary of the 1982 cost estimates is presented. Sources of key cost uncertainties are discussed and the bases for the cost recovery fee calculations are summarized. 17 references, 2 figures, 3 tables

  6. REPOSITORY RADIATION SHIELDING DESIGN GUIDE

    International Nuclear Information System (INIS)

    M. Haas; E.M. Fortsch

    1997-01-01

    The scope of this document includes radiation safety considerations used in the design of facilities for the Yucca Mountain Site Characterization Project (YMP). The purpose of the Repository Radiation Shielding Design Guide is to document the approach used in the radiological design of the Mined Geologic Disposal System (MGDS) surface and subsurface facilities for the protection of workers, the public, and the environment. This document is intended to ensure that a common methodology is used by all groups that may be involved with Radiological Design. This document will also assist in ensuring the long term survivability of the information basis used for radiological safety design and will assist in satisfying the documentation requirements of the licensing body, the Nuclear Regulatory Commission (NRC). This design guide provides referenceable information that is current and maintained under the YMP Quality Assurance (QA) Program. Furthermore, this approach is consistent with maintaining continuity in spite of a changing design environment. This approach also serves to ensure common inter-disciplinary interpretation and application of data

  7. REPOSITORY RADIATION SHIELDING DESIGN GUIDE

    Energy Technology Data Exchange (ETDEWEB)

    M. Haas; E.M. Fortsch

    1997-09-12

    The scope of this document includes radiation safety considerations used in the design of facilities for the Yucca Mountain Site Characterization Project (YMP). The purpose of the Repository Radiation Shielding Design Guide is to document the approach used in the radiological design of the Mined Geologic Disposal System (MGDS) surface and subsurface facilities for the protection of workers, the public, and the environment. This document is intended to ensure that a common methodology is used by all groups that may be involved with Radiological Design. This document will also assist in ensuring the long term survivability of the information basis used for radiological safety design and will assist in satisfying the documentation requirements of the licensing body, the Nuclear Regulatory Commission (NRC). This design guide provides referenceable information that is current and maintained under the YMP Quality Assurance (QA) Program. Furthermore, this approach is consistent with maintaining continuity in spite of a changing design environment. This approach also serves to ensure common inter-disciplinary interpretation and application of data.

  8. Repository Closure and Sealing Approach

    International Nuclear Information System (INIS)

    A.T. Watkins

    2000-01-01

    The scope of this analysis will be to develop the conceptual design of the closure seals and their locations in the Subsurface Facilities. The design will be based on the recently established program requirements for transitioning to the Site Recommendation (SR) design as outlined by ''Approach to Implementing the Site Recommendation Baseline'' (Stroupe 2000) and the ''Monitored Geologic Repository Project Description Document'' (CRWMS M andO 1999b). The objective of this analysis will be to assist in providing a description for the Subsurface Facilities System Description Document, Section 2 and finally to document any conclusions reached in order to contribute and provide support to the SR. This analysis is at a conceptual level and is considered adequate to support the SR design. The final closure barriers and seals for the ventilation shafts, and the north and south ramps will require these openings to be permanently sealed to limit excessive air and water inflows and prevent human intrusion. The major tasks identified with closure in this analysis are: (1) Developing the overall subsurface seal layout and identifying design and operational interfaces for the Subsurface Facilities. (2) Summarizing the general site conditions and general rock characteristic with respect to seal location and describing the seal selected. (3) Identify seal construction materials, methodology of construction and strategic locations including design of the seal and plugs. (4) Discussing methods to prevent human intrusion

  9. Sorption on inactive repository components

    International Nuclear Information System (INIS)

    Gardiner, M.P.; Smith, A.J.; Williams, S.J.

    1990-11-01

    The near-field of an intermediate level/low level radioactive waste repository will contain significant quantities of iron and steel, Magnox and Zircaloy. Their corrosion products may possess significant sorption capacity for radioelements. The sorption of americium and plutonium onto magnesium hydroxide, zirconium hydroxide, colloidal magnetite and colloidal haematite has been studied under conditions typical of the porewater of a cementitious near-field. R D values ≥ 10 5 m g -1 were measured for both actinides on the oxides and hydroxides. These values are at least as great as those measured on crushed 3:1 Blast Furnace Slag/Ordinary Portland cement. Competitive sorption experiments have shown that sorption onto the corrosion products does not take place in preference to that on the cement or the converse. Magnetite and haematite colloids are positively charged in cement-equilibrated water whilst zirconium hydroxide is negatively charged. Crushed cement was found to be positively charged. Simple experiments show that only a small proportion of haematite colloids is potentially mobile through a column of crushed cement. (author)

  10. Sorption on inactive repository components

    International Nuclear Information System (INIS)

    Gardiner, M.P.; Smith, A.J.; Williams, S.J.

    1990-07-01

    The near-field of an intermediate level/low level radioactive waste repository will contain significant quantities of iron and steel, Magnox and Zircaloy. Their corrosion products may possess significant sorption capacity for radioelements. The sorption of americium and plutonium onto magnesium hydroxide, zirconium hydroxide, colloidal magnetite and colloidal haematite has been studied under conditions typical of the porewater of a cementitious near-field. R D values ≥ 10 5 ml g -1 were measured for both actinides on the oxides and hydroxides. These values are at least as great at those measured on crushed 3:1 Blast Furnace Slag/Ordinary Portland Cement. Competitive sorption experiments have shown that sorption onto the corrosion products does not take place in preference to that on the cement or the converse. Magnetite and haematite colloids are positively charged in cement-equilibrated water whilst zirconium hydroxide is negatively charged. Crushed cement was found to be positively charged. Simple experiments show that only a small proportion of haematite colloids is potentially mobile through a column of crushed cement. (author)

  11. Building the repositories to serve

    International Nuclear Information System (INIS)

    Lersch, D.

    1994-01-01

    The project to design and build the Superconducting Super Collider (SSC) Laboratory also includes the exciting opportunity to implement client/server information systems. Lab technologists were eager to take advantage of the cost savings inherent in the open systems and a distributed, client server environment and, at the same time, conscious of the need to provide secure repositories for sensitive data as well as a schedule sensitive acquisition strategy for mission critical software. During the first year of project activity, micro-based project management and business support systems were acquired and implemented to support a small study project of less than 400 people allocating contracts of less than $1 million. The transition to modern business systems capable of supporting more than 10,000 participants (world wide) who would be researching and developing the new technologies that would support the world's largest scientific instrument, a 42 Tevatron, superconducting, super collider became a mission critical event. This paper will present the SSC Laboratory's strategy to balance its commitment to open systems, structured query language (SQL) standards and its success with acquiring commercial off the shelf software to support immediate goals. Included will be an outline of the vital roles played by other labs (Livermore, CERN, Brookhaven, Fermi and others) and a discussion of future collaboration potentials to leverage the information activities of all Department of Energy funded labs

  12. Slope stability and rockfall assessment of volcanic tuffs using RPAS with 2-D FEM slope modelling

    Science.gov (United States)

    Török, Ákos; Barsi, Árpád; Bögöly, Gyula; Lovas, Tamás; Somogyi, Árpád; Görög, Péter

    2018-02-01

    Steep, hardly accessible cliffs of rhyolite tuff in NE Hungary are prone to rockfalls, endangering visitors of a castle. Remote sensing techniques were employed to obtain data on terrain morphology and to provide slope geometry for assessing the stability of these rock walls. A RPAS (Remotely Piloted Aircraft System) was used to collect images which were processed by Pix4D mapper (structure from motion technology) to generate a point cloud and mesh. The georeferencing was made by Global Navigation Satellite System (GNSS) with the use of seven ground control points. The obtained digital surface model (DSM) was processed (vegetation removal) and the derived digital terrain model (DTM) allowed cross sections to be drawn and a joint system to be detected. Joint and discontinuity system was also verified by field measurements. On-site tests as well as laboratory tests provided additional engineering geological data for slope modelling. Stability of cliffs was assessed by 2-D FEM (finite element method). Global analyses of cross sections show that weak intercalating tuff layers may serve as potential slip surfaces. However, at present the greatest hazard is related to planar failure along ENE-WSW joints and to wedge failure. The paper demonstrates that RPAS is a rapid and useful tool for generating a reliable terrain model of hardly accessible cliff faces. It also emphasizes the efficiency of RPAS in rockfall hazard assessment in comparison with other remote sensing techniques such as terrestrial laser scanning (TLS).

  13. Removal of Pb(II) from water by natural zeolitic tuff: kinetics and thermodynamics.

    Science.gov (United States)

    Karatas, Mustafa

    2012-01-15

    The present study was aimed at examining the ability of a natural zeolitic volcanic tuff to remove Pb(II) ions from aqueous solutions under various conditions. The effects of various parameters such as optimum adsorbent mass, contact time, pH of the medium, Pb(II) concentration, and temperature were investigated. In addition, different adsorption isotherms were obtained using concentrations of Pb(II) ions ranging from 1mg/L to 200mg/L. The adsorption process follows second-order reaction kinetics and follows the Langmuir adsorption isotherm. The thermodynamic parameters are discussed in this article, including changes in Gibbs free energy, entropy, and enthalpy, for the adsorption of Pb(II) on tuff, and it is revealed that the adsorption process was spontaneous and exothermic under natural conditions. The maximum removal efficiency of 92% was obtained at a pH of 5 with a 25-min contact time for a 10 g/L solid-to-liquid ratio and an initial heavy metal concentration of 100mg/L. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Slope stability and rockfall assessment of volcanic tuffs using RPAS with 2-D FEM slope modelling

    Directory of Open Access Journals (Sweden)

    Á. Török

    2018-02-01

    Full Text Available Steep, hardly accessible cliffs of rhyolite tuff in NE Hungary are prone to rockfalls, endangering visitors of a castle. Remote sensing techniques were employed to obtain data on terrain morphology and to provide slope geometry for assessing the stability of these rock walls. A RPAS (Remotely Piloted Aircraft System was used to collect images which were processed by Pix4D mapper (structure from motion technology to generate a point cloud and mesh. The georeferencing was made by Global Navigation Satellite System (GNSS with the use of seven ground control points. The obtained digital surface model (DSM was processed (vegetation removal and the derived digital terrain model (DTM allowed cross sections to be drawn and a joint system to be detected. Joint and discontinuity system was also verified by field measurements. On-site tests as well as laboratory tests provided additional engineering geological data for slope modelling. Stability of cliffs was assessed by 2-D FEM (finite element method. Global analyses of cross sections show that weak intercalating tuff layers may serve as potential slip surfaces. However, at present the greatest hazard is related to planar failure along ENE–WSW joints and to wedge failure. The paper demonstrates that RPAS is a rapid and useful tool for generating a reliable terrain model of hardly accessible cliff faces. It also emphasizes the efficiency of RPAS in rockfall hazard assessment in comparison with other remote sensing techniques such as terrestrial laser scanning (TLS.

  15. Monitoring during the stepwise implementation of the Swedish deep repository for spent fuel

    International Nuclear Information System (INIS)

    Baeckblom, Goeran; Almen, Karl-Erik

    2004-03-01

    Monitoring in this report is defined as 'Continuous or repeated observations or measurements of parameters to increase the scientific understanding of the site and the repository, to show compliance with requirements or for adaptation of plans in light of the monitoring results.' The international outlook from IAEA, OECD/NEA, CEC and some country-specific reviews presented in the report forms a necessary background to the Swedish monitoring framework. The implementation of the deep repository in Sweden is executed in phases where monitoring is an inherently integrated activity in the programme. The first phase is the site investigations when Primary Baseline conditions are established. During the following construction phase of the repository, detailed site characterisation continues in conjunction with construction of the access to the deposition area, construction of parts of the deposition area and the central service area. Monitoring is then used to track the changes to the previously established Primary Baseline conditions and distinguishing these imposed changes from natural variations or from other man-made influences. During the initial operation phase, around 200-400 canisters of spent fuel is emplaced and deposition tunnels backfilled. After up-dated evaluations, the phase of regular operation begin, where detailed characterisation, construction of the repository and waste emplacement are concurrent activities. The closure of the repository will take place when all spent fuel has been emplaced, i.e. in the latter part of this century. Monitoring during the stepwise implementation of the repository is executed of several reasons mainly to: describe the Primary Baseline conditions of the repository site, develop and demonstrate understanding of the repository site and the behaviour of engineered barriers, assist in the decision-making process, show compliance with international and national guidelines and regulations. Specific rationales for monitoring are

  16. A new approach to the LILW repository site selection

    International Nuclear Information System (INIS)

    Mele, I.; Zeleznik, N.

    1998-01-01

    After the failure of site selection, which was performed between 1990-1993, the Agency for Radwaste Management was urged to start a new site selection process for low and intermediate level waste (LILW). Since this is the most sensitive and delicate phase of the whole disposal project extensive analyses of foreign and domestic experiences in siting were performed. Three different models were studied and discussed at a workshop on preparation of the siting procedure for LILW repository. The participants invited to the workshop supported the combined approach, to the site selection, which is presented in this paper.(author)

  17. Shaft placement in a bedded salt repository

    International Nuclear Information System (INIS)

    Klasi, M.L.

    1982-10-01

    Preferred shaft pillar sizes and shaft locations were determined with respect to the induced thermal stresses in a generic bedded salt repository at a depth of 610 m with a gross thermal loading of 14.8 W/m 2 . The model assumes isotropic material properties, plane strain and linear elastic behavior. Various shaft locations were analyzed over a 25 year period. The thermal results show that for this time span, the stratigraphy is unimportant except for the region immediately adjacent to the repository. The thermomechanical results show that for the given repository depth of 610 m, a minimum central shaft pillar radius of 244 m is required to equal the material strength in the barrier pillar. An assumed constant stress and constant temperature distribution creep model of the central shaft region adjacent to the repository conservatively overestimates a creep closure of 310 mm in a 6.1 m diameter centrally-located shaft

  18. Evaluasi Website Repositori Institusi Universitas Surabaya

    Directory of Open Access Journals (Sweden)

    Amirul Ulum

    2015-11-01

    Full Text Available The  development  of  institutional  repositories  (IRs  in Indonesia within the broader framework of open access has significant impact on preserving intellectual capital and scholarly communication. Institutional  repositories  play  a  fundamental  role  in  centralizing, preserving,  and  making  accessible  institution’s  intellectual  capital. Evaluation of the system is to determine the functionality the system to meet the users need. Using a descriptive analysis this study wants to evaluate institutional repositories of University of Surabaya. The result is usefull for institution to develop the repository systems.

  19. Biospecimen Repository Access and Data Sharing (BRADS)

    Data.gov (United States)

    U.S. Department of Health & Human Services — BRADS is a repository for data and biospecimens from population health research initiatives and clinical or interventional trials designed and implemented by NICHD’s...

  20. NIMH Repository and Genomics Resources (RGR)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The NIMH Repository and Genomics Resource (RGR) stores biosamples, genetic, pedigree and clinical data collected in designated NIMH-funded human subject studies. The...

  1. Decision theory applied to radioactive repository construction

    International Nuclear Information System (INIS)

    Heilbron Filho, Paulo Fernando Lavalle; Pontedeiro, Elizabeth May

    2001-01-01

    The objective of this article is to present, through the presentation of an example, the applicability of the decision theory on the selection and construction of a repository for low and intermediate radioactive waste. (author)

  2. The Function Biomedical Informatics Research Network Data Repository.

    Science.gov (United States)

    Keator, David B; van Erp, Theo G M; Turner, Jessica A; Glover, Gary H; Mueller, Bryon A; Liu, Thomas T; Voyvodic, James T; Rasmussen, Jerod; Calhoun, Vince D; Lee, Hyo Jong; Toga, Arthur W; McEwen, Sarah; Ford, Judith M; Mathalon, Daniel H; Diaz, Michele; O'Leary, Daniel S; Jeremy Bockholt, H; Gadde, Syam; Preda, Adrian; Wible, Cynthia G; Stern, Hal S; Belger, Aysenil; McCarthy, Gregory; Ozyurt, Burak; Potkin, Steven G

    2016-01-01

    The Function Biomedical Informatics Research Network (FBIRN) developed methods and tools for conducting multi-scanner functional magnetic resonance imaging (fMRI) studies. Method and tool development were based on two major goals: 1) to assess the major sources of variation in fMRI studies conducted across scanners, including instrumentation, acquisition protocols, challenge tasks, and analysis methods, and 2) to provide a distributed network infrastructure and an associated federated database to host and query large, multi-site, fMRI and clinical data sets. In the process of achieving these goals the FBIRN test bed generated several multi-scanner brain imaging data sets to be shared with the wider scientific community via the BIRN Data Repository (BDR). The FBIRN Phase 1 data set consists of a traveling subject study of 5 healthy subjects, each scanned on 10 different 1.5 to 4 T scanners. The FBIRN Phase 2 and Phase 3 data sets consist of subjects with schizophrenia or schizoaffective disorder along with healthy comparison subjects scanned at multiple sites. In this paper, we provide concise descriptions of FBIRN's multi-scanner brain imaging data sets and details about the BIRN Data Repository instance of the Human Imaging Database (HID) used to publicly share the data. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Safety analysis of the post-operational phase

    International Nuclear Information System (INIS)

    Berg, H.P.; Ehrlich, D.

    1991-01-01

    The safety analysis of normal operation covers an analytical study of the system parts ultimate repository - waste forms of the ultimate repository system under normal and accidental operation. On that basis a requirement concept has been developed which entails reactions on planning and design of the repository, and requirements of waste products, packagings and permissible activities. The procedure for the operational phase is explained giving the Konrad repository project as an example. (DG) [de

  4. 48 CFR 227.7108 - Contractor data repositories.

    Science.gov (United States)

    2010-10-01

    ... repositories. 227.7108 Section 227.7108 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS... Technical Data 227.7108 Contractor data repositories. (a) Contractor data repositories may be established when permitted by agency procedures. The contractual instrument establishing the data repository must...

  5. Impact of retrievability of repository design

    International Nuclear Information System (INIS)

    Heijdra, J.J.; Gaag, J. v.d.; Prij, J.

    1995-01-01

    In this paper the impact of the retrievability on the design of the repository will be handled. Retrievability of radioactive waste from a repository in geological formations has received increasing attention during recent years. It is obvious that this retrievability will have consequences in terms of mining engineering, safety and cost. The purpose of the present study is to evaluate cost consequences by comparing two extreme options for retrievable storage. (author). 6 refs., 3 figs

  6. Transfer systems in an underground repository

    International Nuclear Information System (INIS)

    Berg, H.P.; Ehrlich, D.

    1991-01-01

    In addition to logistic problem definitions taking into account the waste types of the wastes to be disposed of and the mining conditions, transport and handling of radioactive wastes in a repository, particularly require the keeping of safety technological marginal conditions mainly resulting from the accident analyses carried out. The realization of these safety technological aspects is described taking the planned Konrad repository as an example. (author)

  7. Chemical risks from nuclear waste repositories

    International Nuclear Information System (INIS)

    Persson, L.

    1988-01-01

    Studies concerning the chemical risks of nuclear waste are reviewed. The radiological toxicity of the material is of primary concern but the potential nonradiological toxicity should not be overlooked as the chemotoxic substances may reach the biosphere from a nuclear waste repository. In the report is concluded that the possible chemotoxic effects of a repository for nuclear waste should be studied as a part of the formal risk assessment of the disposal concept. (author)

  8. A Record of Uranium-Series Transport in Fractured, Unsaturated Tuff at Nopal I, Sierra Peña Blanca, Chihuahua, Mexico

    Science.gov (United States)

    Denton, J.; Goldstein, S. J.; Paviet, P.; Nunn, A. J.; Amato, R. S.; Hinrichs, K. A.

    2015-12-01

    In this study we utilize U-series disequilibria measurements to investigate mineral fluid interactions and the role fractures play in the geochemical evolution of an analogue for a high level nuclear waste repository, the Nopal I uranium ore deposit. Samples of fracture-fill materials have been collected from a vertical drill core and surface fractures. High uranium concentrations in these materials (12-7700 ppm) indicate U mobility and transport from the deposit in the past. U concentrations generally decrease with horizontal distance away from the ore deposit but show no trend with depth. Isotopic activity ratios indicate a complicated geochemical evolution in terms of the timing and extent of actinide mobility, possibly due to changing environmental (redox) conditions over the history of the deposit. 234U/238U activity ratios are generally distinct from secular equilibrium and indicate some degree of open system U behavior during the past 1.2 Ma. However, calculated closed system 238U-234U-230Th model ages are generally >313 ka and >183 ka for the surface fracture and drill core samples respectively, suggesting closed system behavior for U and Th over this most recent time period. Whole rock isochrons drawn for the drill core samples show that at two of three depths fractures have remained closed with respect to U and Th mobility for >200 ka. However, open system behavior for U in the last 350 ka is suggested at 67 m depth. 231Pa/235U activity ratios within error of unity suggest closed system behavior for U and Pa for at least the past 185 ka. 226Ra/230Th activity ratios are typically <1 (0.7-1.2), suggesting recent (<8 ka) radium loss and mobility due to ongoing fluid flow in the fractures. Overall, the mainly closed system behavior of U-Th-Pa over the past ~200 ka provides one indicator of the geochemical immobility of these actinides over long time-scales for potential nuclear waste repositories sited in fractured, unsaturated tuff.

  9. Implementation of the Brazilian national repository

    International Nuclear Information System (INIS)

    Tello, Cledola Cassia Oliveira de

    2013-01-01

    Ionizing radiation in Brazil is used in electricity generation, medicine, industry, agriculture and for research and development purposes. All these activities can generate radioactive waste. At this point, in Brazil, the use of nuclear energy and radioisotopes justifies the construction of a national repository for radioactive wastes of low and intermediate-level. According to Federal Law No. 10308, Brazilian National Commission for Nuclear Energy (CNEN) is responsible for designing and constructing the intermediate and final storages for radioactive wastes. Additionally, a restriction on the construction of Angra 3 is that the repository is under construction until its operation start, attaining some requirements of the Brazilian Environmental Regulator (IBAMA). The RBMN Project (Repository for Low and Intermediate-Level Radioactive Wastes) aims at the implantation of a National Repository for disposal of low and intermediate-level of radiation wastes. This Project has some aspects that are unique in the Brazilian context, especially referring to the time between its construction and the end of its institutional period. This time is about 360 years, when the area will be released for unrestricted uses. It means that the Repository must be safe and secure for more than three hundred years, which is longer than half of the whole of Brazilian history. This aspect is very new for the Brazilian people, bringing a new dimension to public acceptance. Another point is this will be the first repository in South America, bringing a real challenge for the continent. The current status of the Project is summarized. (author)

  10. Interoperability Across the Stewardship Spectrum in the DataONE Repository Federation

    Science.gov (United States)

    Jones, M. B.; Vieglais, D.; Wilson, B. E.

    2016-12-01

    Thousands of earth and environmental science repositories serve many researchers and communities, each with their own community and legal mandates, sustainability models, and historical infrastructure. These repositories span the stewardship spectrum from highly curated collections that employ large numbers of staff members to review and improve data, to small, minimal budget repositories that accept data caveat emptor and where all responsibility for quality lies with the submitter. Each repository fills a niche, providing services that meet the stewardship tradeoffs of one or more communities. We have reviewed these stewardship tradeoffs for several DataONE member repositories ranging from minimally (KNB) to highly curated (Arctic Data Center), as well as general purpose (Dryad) to highly discipline or project specific (NEON). The rationale behind different levels of stewardship reflect resolution of these tradeoffs. Some repositories aim to encourage extensive uptake by keeping processes simple and minimizing the amount of information collected, but this limits the long-term utility of the data and the search, discovery, and integration systems that are possible. Other repositories require extensive metadata input, review, and assessment, allowing for excellent preservation, discovery, and integration but at the cost of significant time for submitters and expense for curatorial staff. DataONE recognizes these different levels of curation, and attempts to embrace them to create a federation that is useful across the stewardship spectrum. DataONE provides a tiered model for repositories with growing utility of DataONE services at higher tiers of curation. The lowest tier supports read-only access to data and requires little more than title and contact metadata. Repositories can gradually phase in support for higher levels of metadata and services as needed. These tiered capabilities are possible through flexible support for multiple metadata standards and services

  11. Research on the calculation method of shale and tuff content: taking tuffaceous reservoirs of X depression in the Hailar–Tamtsag Basin as an example

    International Nuclear Information System (INIS)

    Liu, Sihui; Huang, Buzhou; Pan, Baozhi; Guo, Yuhang; Fang, Chunhui; Wang, Guiping; Sun, Fengxian; Qiu, Haibo; Jiang, Bici

    2015-01-01

    Shale content is known in reservoir evaluation as an important parameter in well logging. However, the log response characteristics are simultaneously affected by shale and tuff existing in tuffaceous sandstone reservoirs. Due to the fact that tuff content exerts an influence on the calculation of shale content, the former is equally important as the latter. Owing to the differences in the source and composition between shale and tuff, the calculation of tuff content using the same methods for shale content cannot meet the accuracy requirements of logging evaluation. The present study takes the tuffaceous reservoirs in the X depression of the Hailar–Tamtsag Basin as an example. The differences in the log response characteristics between shale and tuff are theoretically analyzed and verified using core analysis data. The tuff is then divided into fine- and coarse-grained fractions, according to the differences in the distribution of the radioactive elements, uranium, thorium and potassium. Next, a volume model suitable for tuffaceous sandstone reservoirs is established to include a sandstone matrix, shale, fine-grained tuff, coarse-grained tuff and pore. A comparison of three optimization algorithms shows that the particle swarm optimization (PSO) yields better calculation results with small mean errors. The resistivity differences among shale, fine-grained tuff and coarse-grained tuff are considered in the calculation of saturation. The water saturation of tuffaceous reservoirs is computed using the improved Poupon’s equation, which is suitable for tuffaceous sandstone reservoirs with low water salinity. The method is used in well Y, and is shown to have a good application effect. (paper)

  12. Inverse Dipolar Magnetic Anomaly Over the Volcanic Cone Linked to Reverse Polarity Magnetizations in Lavas and Tuffs - Implications for the Conduit System

    Science.gov (United States)

    Fucugauchi, J. U.; Perez-Cruz, L. L.; Trigo-Huesca, A.

    2012-12-01

    A combined magnetics and paleomagnetic study of Toluquilla monogenetic volcano and associated lavas and tuffs from Valsequillo basin in Central Mexico provides evidence on a magnetic link between lavas, ash tuffs and the underground volcanic conduit system. Paleomagnetic analyses show that lavas and ash tuffs carry reverse polarity magnetizations, which correlate with the inversely polarized dipolar magnetic anomaly over the volcano. The magnetizations in the lava and tuff show similar southward declinations and upward inclinations, supporting petrological inferences that the tuff was emplaced while still hot and indicating a temporal correlation for lava and tuff emplacement. Conduit geometry is one of the important controlling factors in eruptive dynamics of basaltic volcanoes. However volcanic conduits are often not, or only partly, exposed. Modeling of the dipolar anomaly gives a reverse polarity source magnetization associated with a vertical prismatic body with southward declination and upward inclination, which correlates with the reverse polarity magnetizations in the lava and tuff. The study documents a direct correlation of the paleomagnetic records with the underground magmatic conduit system of the monogenetic volcano. Time scale for cooling of the volcanic plumbing system involves a longer period than the one for the tuff and lava, suggesting that magnetization for the source of dipolar anomaly may represent a long time average as compared to the spot readings in the lava and tuff. The reverse polarity magnetizations in lava and tuff and in the underground source body for the magnetic anomaly are interpreted in terms of eruptive activity of Toluquilla volcano at about 1.3 Ma during the Matuyama reverse polarity C1r.2r chron.

  13. Nevada Nuclear Waste Storage Investigations Project: thermal analysis of spent fuel disposal in vertical emplacement boreholes in a welded tuff repository

    International Nuclear Information System (INIS)

    St John, C.M.

    1985-11-01

    Two- and three-dimensional heat transfer analyses were conducted to determine temperatures in the vicinity of a waste canister and an emplacement drift. The effect of emplacement of canisters containing spent fuel in vertical boreholes was simulated for the cases of an emplacement drift either fully ventilated or sealed immediately after canister emplacement. PORFLOW and THERM3D respectively solve the two- and three-dimensional forms of the diffusion equation. In the unventilated case, the effect of radiation was approximated by defining an equivalent radiation thermal conductivity. A simple code, TEMP3D, based on the closed form solutions for constant and decaying heat sources, was also used. Calculations indicate that the temperature at the canister borehole wall will peak at about 215 0 C if the drift is ventilated and about 240 0 C if it is unventilated. The peak temperature occurs sooner in the ventilated case; after 3 to 4 yr versus 9 yr. For a point 1 m from the wall of the emplacement borehole, the corresponding peak temperatures are 150 0 C for the ventilated case and 185 0 C for the unventilated case and occur at about 5 and 17 yr. We assumed that the effect of drift ventilation would be to maintain a uniform temperature of 30 0 C at the drift perimeter. If the drift is unventilated the wall rock temperature peaks some 75 to 100 yr after waste emplacement; reaching about 125 0 C at the mid-height of the drift wall. Comparisons between the results of the three-dimensional analyses performed using TEMP3D and THERM3D indicated that the simpler modeling technique provided a good estimate of temperatures in the immediate vicinity of the canister for both the ventilated and unventilated cases. Comparisons of the results of two- and three-dimensional analyses performed using the PORFLOW and THERM3D codes indicated that the two-dimensional approximation is excellent, except in the immediate vicinity of the canister

  14. Critical assessment of seismic and geomechanics literature related to a high-level nuclear waste underground repository

    Energy Technology Data Exchange (ETDEWEB)

    Kana, D.D.; Vanzant, B.W.; Nair, P.K. [Southwest Research Inst., San Antonio, TX (USA). Center for Nuclear Waste Regulatory Analyses; Brady, B.H.G. [ITASCA Consulting Group, Inc., Minneapolis, MN (USA)

    1991-06-01

    A comprehensive literature assessment has been conducted to determine the nature and scope of technical information available to characterize the seismic performance of an underground repository and associated facilities. Significant deficiencies were identified in current practices for prediction of seismic response of underground excavations in jointed rock. Conventional analytical methods are based on a continuum representation of the host rock mass. Field observations and laboratory experiments indicate that, in jointed rock, the behavior of the joints controls the overall performance of underground excavations. Further, under repetitive seismic loading, shear displacement develops progressively at block boundaries. Field observations correlating seismicity and groundwater conditions have provided significant information on hydrological response to seismic events. However, lack of a comprehensive model of geohydrological response to seismicity has limited the transportability conclusions from field observations. Based on the literature study, matters requiring further research in relation to the Yucca Mountain repository are identified. The report focuses on understanding seismic processes in fractured tuff, and provides a basis for work on the geohydrologic response of a seismically disturbed rock mass. 220 refs., 43 figs., 11 tabs.

  15. Critical assessment of seismic and geomechanics literature related to a high-level nuclear waste underground repository

    International Nuclear Information System (INIS)

    Kana, D.D.; Vanzant, B.W.; Nair, P.K.

    1991-06-01

    A comprehensive literature assessment has been conducted to determine the nature and scope of technical information available to characterize the seismic performance of an underground repository and associated facilities. Significant deficiencies were identified in current practices for prediction of seismic response of underground excavations in jointed rock. Conventional analytical methods are based on a continuum representation of the host rock mass. Field observations and laboratory experiments indicate that, in jointed rock, the behavior of the joints controls the overall performance of underground excavations. Further, under repetitive seismic loading, shear displacement develops progressively at block boundaries. Field observations correlating seismicity and groundwater conditions have provided significant information on hydrological response to seismic events. However, lack of a comprehensive model of geohydrological response to seismicity has limited the transportability conclusions from field observations. Based on the literature study, matters requiring further research in relation to the Yucca Mountain repository are identified. The report focuses on understanding seismic processes in fractured tuff, and provides a basis for work on the geohydrologic response of a seismically disturbed rock mass. 220 refs., 43 figs., 11 tabs

  16. Strontium Isotopes in Pore Water as an Indicator of Water Flux at the Proposed High-Level Radioactive Waste Repository, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Marshall, B.; Futa, K.

    2004-01-01

    The proposed high-level radioactive waste repository at Yucca Mountain, Nevada, would be constructed in the high-silica rhyolite (Tptp) member of the Miocene-age Topopah Spring Tuff, a mostly welded ash-flow tuff in the ∼500-m-thick unsaturated zone. Strontium isotope compositions have been measured in pore water centrifuged from preserved core samples and in leachates of pore-water salts from dried core samples, both from boreholes in the Tptp. Strontium isotope ratios ( 87 Sr/ 86 Sr) vary systematically with depth in the surface-based boreholes. Ratios in pore water near the surface (0.7114 to 0.7124) reflect the range of ratios in soil carbonate (0.7112 to 0.7125) collected near the boreholes, but ratios in the Tptp (0.7122 to 0.7127) at depths of 150 to 370 m have a narrower range and are more radiogenic due to interaction with the volcanic rocks (primarily non-welded tuffs) above the Tptp. An advection-reaction model relates the rate of strontium dissolution from the rocks with flow velocity. The model results agree with the low transport velocity (∼2 cm per year) calculated from carbon-14 data by I.C. Yang (2002, App. Geochem., v. 17, no. 6, p. 807-817). Strontium isotope ratios in pore water from Tptp samples from horizontal boreholes collared in tunnels at the proposed repository horizon have a similar range (0.7121 to 0.7127), also indicating a low transport velocity. Strontium isotope compositions of pore water below the proposed repository in core samples from boreholes drilled vertically downward from tunnel floors are more varied, ranging from 0.7112 to 0.7127. The lower ratios ( 87 Sr/ 86 Sr of 0.7115. Ratios lower than 0.7115 likely reflect interaction of construction water with concrete in the tunnel inverts, which had an 87 Sr/ 86 Sr < 0.709. These low Sr ratios indicate penetration of construction water to depths of ∼20 m below the tunnels within three years after construction, a transport velocity of ∼7 m per year. These studies show that

  17. Busted Butte : final report on laboratory radionuclide migration experiments in non-welded tuff under unsaturated and saturated conditions

    International Nuclear Information System (INIS)

    Vandergraaf, T.T.; Drew, D.J.; Ticknor, K.V.; Hamon, C.J.

    2004-01-01

    Three blocks of non-welded tuff, one nominally one cubic foot (trial block) in volume and the other two, nominally one cubic meter (1 m 3 ) in volume, were excavated from the Busted Butte Test Facility on the Nevada Test Site in 1999 and transported to the Atomic Energy of Canada Limited Whiteshell Laboratories in Pinawa, Manitoba. The trial block and one of the 1-m 3 blocks were used for radionuclide migration experiments under unsaturated conditions; the remaining 1-m3 block was used for similar migration experiments under saturated conditions. After a vertical flow of synthetic transport solution was set up under unsaturated conditions, a suite of conservative and chemically reactive radionuclide tracers was injected at volumetric flow rates of 20 mL/hr in the trial block, and 10 mL/hr in two locations on the upper surface of the 1-m 3 block. These flow rates correspond to infiltration rates of about 120 cm/year and about 17 cm/year, respectively. The duration of the migration experiment in the trial block was 87 days, while the migration experiment in the 1-m3 block was performed for a period of 588 days. Results obtained from the migration experiment in the trial block showed that transport of 95m+99 Tc, injected as the pertechnetate (an)ion, was slightly faster than that of the transport solution, using tritiated water ( 3 H 2 0) as a flow indicator. Retardation of 237 Np was consistent with that predicted from results obtained in supporting static batch sorption studies. Post-migration analysis of the flow field in the trial block showed that the front of the 22 Na plume had migrated about half the distance through the block, and that 60 Co and 137 Cs had been retained near the inlet. This observation agrees qualitatively with that predicted from the results obtained in static batch sorption studies. In the larger-scale experiment, the transport behavior of Tc was also very similar to that of the transport solution. None of the other radionuclide tracers

  18. A subaqueous welded tuff from the Ordovician of County Waterford, Ireland

    Science.gov (United States)

    Fritz, William J.; Stillman, Chris J.

    1996-01-01

    The Metal Man Tuff (MMT) from the Ordovician of County Waterford, Ireland was emplaced and welded in water depths greater than the thickness of the pyroclastic flow. The MMT is the basal member of the Middle Tramore Volcanic Formation (MTVF) of the 5-km-thick Tramore Group. The MMT consists of a 10-m-thick basal graded zone that represents a pyroclastic flow consisting of angular clasts of black mudstone, pumice, gray flow banded rhyolite, and pink massive rhyolite set in a matrix of non-deformed ash shards and pumice. Maximum grain size grades from large cobbles and small boulders to pebbles. The basal 10-30 cm is depleted with respect to the largest boulders resulting in an inversely graded basal layer. The basal graded zone passes upward into a transition zone with a strong eutaxitic foliation defined by elongated fiamme of mudstone and flattened pumice. Overlying this is an upper welded zone with a pronounced eutaxitic foliation, columnar jointing, flattened ash shards and shards deformed around phenocrysts and spheroids. The presence of these features indicate that the deposit is welded, was hot, and was in motion as the shards deformed. The MMT represents a pyroclastic flow that was a hot primary product of an eruption rather than re-mobilized cold pyroclastic debris. The MMT is bounded by suspension deposited fine-grained tuff, tuffaceous mudstone and terrigenous mudstone deposited below storm wave base. Many of the mudstone horizons contain brachipod faunas from shelf-depth water. Nowhere in the 5-km-thick Tramore Group is there terrigenous sandstone, evidence of unidirectional flowing water, nor any indication of shoreline, alluvial environments, or subaerial exposure. It thus seems reasonable to conclude that the MMT was emplaced and welded subaqueously. The geochemistry of the MMT is typical of other high-silica (70-78 wt.% SiO 2) rhyolite from the Ordovician of Ireland. The chemistry of the MMT is consistent from top to bottom allowing it to be

  19. The volcanic foundation of Dutch architecture : Use of Rhenish tuff and trass in the Netherlands in the past two millennia

    NARCIS (Netherlands)

    Nijland, TG; van Hees, R.P.J.

    2016-01-01

    Occasionally, a profound but distant connection between volcano and culture exists. This is the case between the volcanic Eifel region in Germany and historic construction in the Netherlands, with the river Rhine as physical and enabling connection. Volcanic tuff from the Eifel comprises a

  20. Magmatism, ash-flow tuffs, and calderas of the ignimbrite flareup in the western Nevada volcanic field, Great Basin, USA

    Science.gov (United States)

    Christopher D. Henry,; John, David A.

    2013-01-01

    The western Nevada volcanic field is the western third of a belt of calderas through Nevada and western Utah. Twenty-three calderas and their caldera-forming tuffs are reasonably well identified in the western Nevada volcanic field, and the presence of at least another 14 areally extensive, apparently voluminous ash-flow tuffs whose sources are unknown suggests a similar number of undiscovered calderas. Eruption and caldera collapse occurred between at least 34.4 and 23.3 Ma and clustered into five ∼0.5–2.7-Ma-long episodes separated by quiescent periods of ∼1.4 Ma. One eruption and caldera collapse occurred at 19.5 Ma. Intermediate to silicic lavas or shallow intrusions commonly preceded caldera-forming eruptions by 1–6 Ma in any specific area. Caldera-related as well as other magmatism migrated from northeast Nevada to the southwest through time, probably resulting from rollback of the formerly shallow-dipping Farallon slab. Calderas are restricted to the area northeast of what was to become the Walker Lane, although intermediate and effusive magmatism continued to migrate to the southwest across the future Walker Lane.Most ash-flow tuffs in the western Nevada volcanic field are rhyolites, with approximately equal numbers of sparsely porphyritic (≤15% phenocrysts) and abundantly porphyritic (∼20–50% phenocrysts) tuffs. Both sparsely and abundantly porphyritic rhyolites commonly show compositional or petrographic evidence of zoning to trachydacites or dacites. At least four tuffs have volumes greater than 1000 km3, with one possibly as much as ∼3000 km3. However, the volumes of most tuffs are difficult to estimate, because many tuffs primarily filled their source calderas and/or flowed and were deposited in paleovalleys, and thus are irregularly distributed.Channelization and westward flow of most tuffs in paleovalleys allowed them to travel great distances, many as much as ∼250 km (original distance) to what is now the western foothills of the

  1. Evaluation of engineering aspects of backfill placement for high level nuclear waste (HLW) deep geologic repositories

    International Nuclear Information System (INIS)

    Roberds, W.; Kleppe, J.; Gonano, L.

    1984-04-01

    This report includes the identification and subjective evaluation of alternative schemes for backfilling around waste packages and within emplacement rooms. The aspects of backfilling specifically considered in this study include construction and testing; costs have not been considered. However, because construction and testing are simply implementation and verification of design, a design basis for backfill is required. A generic basis has been developed for this study by first identifying qualitative performance objectives for backfill and then weighting each with respect to its potential influence on achieving the repository system performance objectives. Alternative backfill materials and additives have been identified and evaluated with respect to the perceived extent to which each combination can be expected to achieve the backfill design basis. Several distinctly different combinations of materials and additives which are perceived to have the highest potential for achieving the backfill design basis have been selected for further study. These combinations include zeolite/clinoptilolite, bentonite, muck, and muck mixed with bentonite. Feasible alternative construction and testing procedures for each selected combination have been discussed. Recommendations have been made regarding appropriate backfill schemes for hard rock (i.e., basalt at Hanford, Washington, tuff at Nevada Test Site, and generic granite) and salt (i.e., domal salt on the Gulf Coast and generic bedded salt). 27 references, 8 figures, 31 tables

  2. Environmental release of carbon-14 gas from a hypothetical nuclear waste repository

    International Nuclear Information System (INIS)

    Lehto, M.A.; Merrell, G.B.

    1994-01-01

    Radioisotopes may form gases in a spent nuclear fuel waste package due to elevated temperatures or degradation of the fuel rods. Radioactive carbon-14, as gaseous carbon dioxide, is one of the gaseous radioisotopes of concern at an underground disposal facility for spent nuclear fuel and high-level radioactive waste. Carbon-14 dioxide may accumulate inside an intact waste container. Upon breach of the container, a potentially large pulse of carbon-14 dioxide gas may be released to the surrounding environment, followed by a lower, long-term continuous release. If the waste were disposed of in an unsaturated geologic environment, the carbon-14 gas would begin to move through the unsaturated zone to the accessible environment. This study investigates the transport of radioactive carbon-14 gas in geologic porous media using a one-dimensional analytical solution. Spent nuclear fuel emplaced in a deep geologic repository located at a generic unsaturated tuff site is analyzed. The source term for the carbon-14 gas and geologic parameters was obtained from previously published materials. The one-dimensional analytical solution includes diffusion, advection, radionuclide retardation, and radioactive decay terms. Two hypothetical sites are analyzed. One is dominated by advective transport, and the other is dominated by diffusive transport. The dominant transport mechanism at an actual site depends on the site characteristics. Results from the simulations include carbon-14 dioxide travel times to the accessible environment and the total release to the environment over a 10,000-year period. The results are compared to regulatory criteria

  3. Fuel cycle covariance of plutonium and americium separations to repository capacity using information theoretic measures

    International Nuclear Information System (INIS)

    Scopatz, Anthony; Schneider, Erich; Li, Jun; Yim, Man-Sung

    2011-01-01

    A light water reactor, fast reactor symbiotic fuel cycle scenario was modeled and parameterized based on thirty independent inputs. Simultaneously and stochastically choosing different values for each of these inputs and performing the associated fuel cycle mass-balance calculation, the fuel cycle itself underwent Monte Carlo simulation. A novel information theoretic metric is postulated as a measure of system-wide covariance. This metric is the coefficient of variation of the set of uncertainty coefficients generated from 2D slices of a 3D contingency table. It is then applied to the fuel cycle, taking fast reactor used fuel plutonium and americium separations as independent variables and the capacity of a fully-loaded tuff repository as the response. This set of parameters is known from prior studies to have a strong covariance. When measured with all 435 other input parameters possible, the fast reactor plutonium and americium separations pair was found to be ranked the second most covariant. This verifies that the coefficient of variation metric captures the desired sensitivity of sensitivity effects in the nuclear fuel cycle. (author)

  4. Analysis of emplacement borehole rock and liner behavior for a repository at Yucca Mountain

    International Nuclear Information System (INIS)

    Lorig, L.J.; Dasgupta, B.

    1989-09-01

    This report presents the results of studies aimed at assessing the quasi-static behavior of both the rock surrounding an emplacement borehole and the lining within an emplacement borehole for a nuclear waste repository in tuff. Two-dimensional thermomechanical analyses of conditions similar to those representative of the horizontal emplacement option were performed using a distinct element code. Three different behavior models (equivalent continuum, wedge, and parallel joint) were used to investigate the state of deformation at 0 and 100 years following waste emplacement. Three different rock strength assumptions were studied corresponding to ''design,'' ''recommended'' and ''limit'' values given in the Nevada Nuclear Waste Storage Investigation (NNWSI) Project Site Characterization Plan Conceptual Design Report (MacDougall et al., 1987). The ground reaction curve concept is introduced to study the potential liner loading resulting from thermally induced borehole closure. The report concludes that for the conditions and parameters assumed, liners may not be significantly loaded by borehole closure, because predicted closures will likely be less than tolerances required to install the lining. The report also concludes that gravity loading of linings by blocks which fall from the surrounding rock should not over-stress the lining. 25 refs., 51 figs., 14 tabs

  5. Mineralogy, geochemistry and low grade metamorphism of green tuffs of Karaj formation in Hesarbon area (south west Firoozkooh

    Directory of Open Access Journals (Sweden)

    Shiva Bahrami

    2017-03-01

    Full Text Available Green tuffs of middle Eocene age in Hesarbon area, south west of Firoozkuh (East of Central Alborz consist of a thick sequence of lithic-, crystal-,vitric-and calcareous-tuffs. Microscopic and x-ray diffraction studies show plagioclase (albite and oligoclase, alkali feldspar (sanidine, quartz, cristobalite, biotite and hornblende are the major minerals in the rocks studied. Secondary minerals such as analcime, chlorite, prehnite and clay minerals are mainly present in the groundmass of the rocks. Extensive tectonic activities have created a variety of structural features including numerous folds and faults and therefore, have caused the green tuffs to be crushed and converted to breccia tuffs in many parts. Veins and cavities are filled by considerable amounts of zeolitic minerals including heulandite group, clinoptilolite and natrolite along with calcite and secondary quartz. Based on geochemical data, they lie on the dacite and rhyodacite field showing a calc-alkaline nature in the corresponding diagrams. According to the chondrite and primitive mantle normalized diagrams of trace elements, negative anomalies of Eu, Nb, Ti, P and depletion of HFSE together with their position in the petrogenesis discrimination diagrams, it is most likely that these rocks are formed in the active continental margin of a subduction zone. The existence of analcime and prehnite in the groundmass demonstrate that these rocks have undergone some degrees of low-grade metamorphism due to the overburden of the layers in the temperature range 200-300 °C. The present study shows that zeolite minerals filling the fractures and cavities of tuffs are precipitated by hydrothermal fluids with a neutral pH to acidic

  6. Neogene fallout tuffs from the Yellowstone hotspot in the Columbia Plateau region, Oregon, Washington and Idaho, USA.

    Directory of Open Access Journals (Sweden)

    Barbara P Nash

    Full Text Available Sedimentary sequences in the Columbia Plateau region of the Pacific Northwest ranging in age from 16-4 Ma contain fallout tuffs whose origins lie in volcanic centers of the Yellowstone hotspot in northwestern Nevada, eastern Oregon and the Snake River Plain in Idaho. Silicic volcanism began in the region contemporaneously with early eruptions of the Columbia River Basalt Group (CRBG, and the abundance of widespread fallout tuffs provides the opportunity to establish a tephrostratigrahic framework for the region. Sedimentary basins with volcaniclastic deposits also contain diverse assemblages of fauna and flora that were preserved during the Mid-Miocene Climatic Optimum, including Sucker Creek, Mascall, Latah, Virgin Valley and Trout Creek. Correlation of ashfall units establish that the lower Bully Creek Formation in eastern Oregon is contemporaneous with the Virgin Valley Formation, the Sucker Creek Formation, Oregon and Idaho, Trout Creek Formation, Oregon, and the Latah Formation in the Clearwater Embayment in Washington and Idaho. In addition, it can be established that the Trout Creek flora are younger than the Mascall and Latah flora. A tentative correlation of a fallout tuff from the Clarkia fossil beds, Idaho, with a pumice bed in the Bully Creek Formation places the remarkably well preserved Clarkia flora assemblage between the Mascall and Trout Creek flora. Large-volume supereruptions that originated between 11.8 and 10.1 Ma from the Bruneau-Jarbidge and Twin Falls volcanic centers of the Yellowstone hotspot in the central Snake River Plain deposited voluminous fallout tuffs in the Ellensberg Formation which forms sedimentary interbeds in the CRBG. These occurrences extend the known distribution of these fallout tuffs 500 km to the northwest of their source in the Snake River Plain. Heretofore, the distal products of these large eruptions had only been recognized to the east of their sources in the High Plains of Nebraska and Kansas.

  7. Neogene fallout tuffs from the Yellowstone hotspot in the Columbia Plateau region, Oregon, Washington and Idaho, USA.

    Science.gov (United States)

    Nash, Barbara P; Perkins, Michael E

    2012-01-01

    Sedimentary sequences in the Columbia Plateau region of the Pacific Northwest ranging in age from 16-4 Ma contain fallout tuffs whose origins lie in volcanic centers of the Yellowstone hotspot in northwestern Nevada, eastern Oregon and the Snake River Plain in Idaho. Silicic volcanism began in the region contemporaneously with early eruptions of the Columbia River Basalt Group (CRBG), and the abundance of widespread fallout tuffs provides the opportunity to establish a tephrostratigrahic framework for the region. Sedimentary basins with volcaniclastic deposits also contain diverse assemblages of fauna and flora that were preserved during the Mid-Miocene Climatic Optimum, including Sucker Creek, Mascall, Latah, Virgin Valley and Trout Creek. Correlation of ashfall units establish that the lower Bully Creek Formation in eastern Oregon is contemporaneous with the Virgin Valley Formation, the Sucker Creek Formation, Oregon and Idaho, Trout Creek Formation, Oregon, and the Latah Formation in the Clearwater Embayment in Washington and Idaho. In addition, it can be established that the Trout Creek flora are younger than the Mascall and Latah flora. A tentative correlation of a fallout tuff from the Clarkia fossil beds, Idaho, with a pumice bed in the Bully Creek Formation places the remarkably well preserved Clarkia flora assemblage between the Mascall and Trout Creek flora. Large-volume supereruptions that originated between 11.8 and 10.1 Ma from the Bruneau-Jarbidge and Twin Falls volcanic centers of the Yellowstone hotspot in the central Snake River Plain deposited voluminous fallout tuffs in the Ellensberg Formation which forms sedimentary interbeds in the CRBG. These occurrences extend the known distribution of these fallout tuffs 500 km to the northwest of their source in the Snake River Plain. Heretofore, the distal products of these large eruptions had only been recognized to the east of their sources in the High Plains of Nebraska and Kansas.

  8. SUBSURFACE REPOSITORY INTEGRATED CONTROL SYSTEM DESIGN

    International Nuclear Information System (INIS)

    Randle, D.C.

    2000-01-01

    The primary purpose of this document is to develop a preliminary high-level functional and physical control system architecture for the potential repository at Yucca Mountain. This document outlines an overall control system concept that encompasses and integrates the many diverse process and communication systems being developed for the subsurface repository design. This document presents integrated design concepts for monitoring and controlling the diverse set of subsurface operations. The Subsurface Repository Integrated Control System design will be composed of a series of diverse process systems and communication networks. The subsurface repository design contains many systems related to instrumentation and control (I andC) for both repository development and waste emplacement operations. These systems include waste emplacement, waste retrieval, ventilation, radiological and air monitoring, rail transportation, construction development, utility systems (electrical, lighting, water, compressed air, etc.), fire protection, backfill emplacement, and performance confirmation. Each of these systems involves some level of I andC and will typically be integrated over a data communications network throughout the subsurface facility. The subsurface I andC systems will also interface with multiple surface-based systems such as site operations, rail transportation, security and safeguards, and electrical/piped utilities. In addition to the I andC systems, the subsurface repository design also contains systems related to voice and video communications. The components for each of these systems will be distributed and linked over voice and video communication networks throughout the subsurface facility. The scope and primary objectives of this design analysis are to: (1) Identify preliminary system-level functions and interfaces (Section 6.2). (2) Examine the overall system complexity and determine how and on what levels the engineered process systems will be monitored

  9. SUBSURFACE REPOSITORY INTEGRATED CONTROL SYSTEM DESIGN

    Energy Technology Data Exchange (ETDEWEB)

    D.C. Randle

    2000-01-07

    The primary purpose of this document is to develop a preliminary high-level functional and physical control system architecture for the potential repository at Yucca Mountain. This document outlines an overall control system concept that encompasses and integrates the many diverse process and communication systems being developed for the subsurface repository design. This document presents integrated design concepts for monitoring and controlling the diverse set of subsurface operations. The Subsurface Repository Integrated Control System design will be composed of a series of diverse process systems and communication networks. The subsurface repository design contains many systems related to instrumentation and control (I&C) for both repository development and waste emplacement operations. These systems include waste emplacement, waste retrieval, ventilation, radiological and air monitoring, rail transportation, construction development, utility systems (electrical, lighting, water, compressed air, etc.), fire protection, backfill emplacement, and performance confirmation. Each of these systems involves some level of I&C and will typically be integrated over a data communications network throughout the subsurface facility. The subsurface I&C systems will also interface with multiple surface-based systems such as site operations, rail transportation, security and safeguards, and electrical/piped utilities. In addition to the I&C systems, the subsurface repository design also contains systems related to voice and video communications. The components for each of these systems will be distributed and linked over voice and video communication networks throughout the subsurface facility. The scope and primary objectives of this design analysis are to: (1) Identify preliminary system-level functions and interfaces (Section 6.2). (2) Examine the overall system complexity and determine how and on what levels the engineered process systems will be monitored, controlled, and

  10. In situ changes in the moisture content of heated, welded tuff based on thermal neutron measurements

    International Nuclear Information System (INIS)

    Ramirez, A.L.; Carlson, R.C.; Buscheck, T.A.

    1991-07-01

    Thermal neutron logs were collected to monitor changes in moisture content within a welded tuff rock mass heated from a borehole containing an electrical heater which remained energized for 195 days. Thermal neutron measurements were made in sampling boreholes before, during and after heating. The results generally corroborated our conceptual understanding of hydrothermal flow as well as most of the numerical modeling conducting for this study. Conceptual models have been developed in conjunction with the numerical model calculations to explain differences in the drying and re-wetting behavior above and below the heater. Numerical modeling indicated that the re-wetting of the dried-out zone was dominated by the binary diffusion of water vapor through fractures. Saturation gradients in the rock matrix resulted in relative humidity gradients which drove water vapor (primarily along fractures) back to the dried-out zone where it condensed along the fracture walls and was imbibed by the matrix. 4 refs., 28 figs

  11. Performance predictions for mechanical excavators in Yucca Mountain tuffs; Yucca Mountain Site Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Ozdemir, L.; Gertsch, L.; Neil, D.; Friant, J. [Colorado School of Mines, Golden, CO (United States). Earth Mechanics Inst.

    1992-09-01

    The performances of several mechanical excavators are predicted for use in the tuffs at Yucca Mountain: Tunnel boring machines, the Mobile Miner, a roadheader, a blind shaft borer, a vertical wheel shaft boring machine, raise drills, and V-Moles. Work summarized is comprised of three parts: Initial prediction using existing rock physical property information; Measurement of additional rock physical properties; and Revision of the initial predictions using the enhanced database. The performance predictions are based on theoretical and empirical relationships between rock properties and the forces-experienced by rock cutters and bits during excavation. Machine backup systems and excavation design aspects, such as curves and grades, are considered in determining excavator utilization factors. Instanteous penetration rate, advance rate, and cutter costs are the fundamental performance indicators.

  12. Bulk and mechanical properties of the Paintbrush tuff recovered from borehole USW NRG-6: Data report

    International Nuclear Information System (INIS)

    Martin, R.J.; Boyd, P.J.; Noel, J.S.; Price, R.H.

    1994-11-01

    Experimental results are presented for bulk and mechanical properties measurements on specimens of the Paintbrush tuff recovered from borehole USW NRG-6 at Yucca Mountain, Nevada. Measurements have been performed on four thermal/mechanical units, TCw, PTn, TSw1 and TSw2. On each specimen the following bulk properties have been reported: dry bulk density, saturated bulk density, average grain density, and porosity. Unconfined compression to failure, confined compression to failure, and indirect tensile strength tests were performed on selected specimens recovered from the borehole. In addition, compressional and shear wave velocities were measured on specimens designated for unconfined compression and confined compression experiments. Measurements were conducted at room temperature on nominally water saturated specimens; however, some specimens of PTn were tested in a room dry condition. The nominal strain rate for the fracture experiments was 10 -5 s -1

  13. Fons antic i repositoris universitaris a Espanya

    Directory of Open Access Journals (Sweden)

    Herrera Morillas, José Luis

    2015-12-01

    Full Text Available Es mostra la presència de col·leccions de fons antic en els repositoris de les biblioteques universitàries espanyoles després d'analitzar tots els repositoris. Per a aquesta anàlisi, com a part de la metodologia emprada, s'ha elaborat un model o llista que consta d'onze elements. Del conjunt de les universitats espanyoles, seixanta tenen repositoris, vint-i-vuit dels quals (16,8 % disposen de col·leccions de fons antic. Com que del concepte de repositori institucional no sembla desprendre's que tingui com a finalitat incloure aquest tipus de col·leccions, es reflexiona sobre la peculiaritat que una part dels repositoris universitaris espanyols inclogui col·leccions d'aquestes característiques.Se muestra la presencia de colecciones de fondo antiguo en los repositorios de las bibliotecas universitarias españolas después de analizar todos los repositorios. Para este análisis, como parte de la metodología empleada, se ha elaborado un modelo o lista que consta de once elementos. Del conjunto de las universidades españolas, sesenta cuentan con repositorios y, de estos, veintiocho (16,8 % disponen de colecciones de fondo antiguo. Debido a que del concepto de repositorio institucional no parece desprenderse que tenga como finalidad albergar este tipo de colecciones, se hace una reflexión sobre la peculiaridad de que parte de los repositorios universitarios españoles incluya colecciones de estas características.This paper uses an analysis of the repositories of Spanish universities to identify which institutions contain rare book and manuscript collections. The method used in this analysis involved examining each university on the basis of a list comprising eleven elements. A total of 60 universities were found to have repositories but only 28 (16.8 % of these contained rare book and manuscript collections. In the light of these figures, which suggest that Spanish university repositories do not generally consider the preservation of rare

  14. Analysis of computational vulnerabilities in digital repositories

    Directory of Open Access Journals (Sweden)

    Valdete Fernandes Belarmino

    2015-04-01

    Full Text Available Objective. Demonstrates the results of research that aimed to analyze the computational vulnerabilities of digital directories in public Universities. Argues the relevance of information in contemporary societies like an invaluable resource, emphasizing scientific information as an essential element to constitute scientific progress. Characterizes the emergence of Digital Repositories and highlights its use in academic environment to preserve, promote, disseminate and encourage the scientific production. Describes the main software for the construction of digital repositories. Method. The investigation identified and analyzed the vulnerabilities that are exposed the digital repositories using Penetration Testing running. Discriminating the levels of risk and the types of vulnerabilities. Results. From a sample of 30 repositories, we could examine 20, identified that: 5% of the repositories have critical vulnerabilities, 85% high, 25% medium and 100% lowers. Conclusions. Which demonstrates the necessity to adapt actions for these environments that promote informational security to minimizing the incidence of external and / or internal systems attacks.Abstract Grey Text – use bold for subheadings when needed.

  15. Nonequilibrium sorptive behavior of cobalt, cesium, and strontium on Bandelier Tuff: experiments and analysis

    International Nuclear Information System (INIS)

    Fuentes, H.R.; Polzer, W.L.; Essington, E.H.; Roensch, F.R.

    1985-01-01

    Information is presented on the nonequilibrium sorption of cobalt, cesium and strontium on Bandelier Tuff. Both adsorption and desorption were studied in the batch at 25 0 C with constant mixing. The reaction solutions consisted of 20 mg/L of stable cobalt, cesium or strontium with their radioactive tracers 60 Co, 137 Cs or 85 Sr, in 0.01N CaCl 2 solution. Adsorption equilibrium occurs rapidly for strontium, somewhat more slowly for cesium, and very slowly for cobalt. The degree of adsorption is approximately 19% for stronium 49% for cesium, and 84% for cobalt. Desorption (leaching) initially occurs in a relatively rapid step followed by a much slower rate. The relative adsorption and desorption rates can be explained or predicted by theoretical considerations of the Modified Freundlich isotherm and Hill Plot analyses of equilibrium sorption data. The Modified Freundlich isotherm analysis predicts that soil will exhibit ranges in relative energies of sorption and in reaction rates; the Hill Plot analysis predicts interactions among sorption sites. Nonequilibrium sorption data indicate that the ranges in relative energies and reaction rates are different for specific solutes and are dependent on interactions among sorption sites; the greater the interaction among sorption sites, the greater the range of reaction rates. The results of this study suggest that equilibrium models may be adequate to describe the movement of strontium in Bandelier Tuff under dynamic flow conditions. However, nonequilibrium models, in all probability, will be needed to describe the movement of cesium and cobalt under those same conditions. 9 references, 6 figures, 4 tables

  16. Stratigraphy, sedimentology and eruptive mechanisms in the tuff cone of El Golfo (Lanzarote, Canary Islands)

    Science.gov (United States)

    Pedrazzi, Dario; Martí, Joan; Geyer, Adelina

    2013-07-01

    The tuff cone of El Golfo on the western coast of Lanzarote (Canary Islands) is a typical hydrovolcanic edifice. Along with other edifices of the same age, it was constructed along a fracture oriented NEE-SWW that coincides with the main structural trend of recent volcanism in this part of the island. We conducted a detailed stratigraphic study of the succession of deposits present in this tuff cone and here interpret them in light of the depositional processes and eruptive dynamics that we were able to infer. The eruptive sequence is represented by a succession of pyroclastic deposits, most of which were emplaced by flow, plus a number of air-fall deposits and ballistic blocks and bombs. We distinguished five different eruptive/depositional stages on the basis of differences in inferred current flow regimes and fragmentation efficiencies represented by the resulting deposits; the different stages may be related to variations in the explosive energy. Eight lithofacies were identified based on sedimentary discontinuities, grain size, components, variations in primary laminations and bedforms. The volcanic edifice was constructed very rapidly around the vent, and this is inferred to have controlled the amount of water that was able to enter the eruption conduit. The sedimentological characteristics of the deposits and the nature and distribution of palagonitic alteration suggest that most of the pyroclastic succession in El Golfo was deposited in a subaerial environment. This type of hydrovolcanic explosive activity is common in the coastal zones of Lanzarote and the other Canary Islands and is one of the main potential hazards that could threaten the human population of this archipelago. Detailed studies of these hydrovolcanic eruptions such as the one we present here can help volcanologists understand the hazards that this type of eruption can generate and provide essential information for undertaking risk assessment in similar volcanic environments.

  17. Paleotransport of lanthanides and strontium recorded in calcite compositions from tuffs at Yucca Mountain, Nevada, USA

    International Nuclear Information System (INIS)

    Vaniman, D.T.; Chipera, S.J.

    1996-01-01

    Secondary calcite occurs in both saturated and unsaturated hydrologic zones (SZ and UZ, respectively) in the tuffs at Yucca Mountain, Nevada, USA. In the upper UZ, the major constituents of the calcite crystal structure (C, O) have surface origins. At greater depth there is a open-quotes barren zone,close quotes straddling the water table, where calcite is rare and mixing of surface and subsurface sources may occur. Deep in the SZ, distinctive Mn calcites reflect deep sources, including Ca released as analcime or albite formed and carbonates derived from underlying Paleozoic rocks. In the UZ and in the barren zone, above the deep Mn calcites, variations in calcite lanthanide chemistry can be used to distinguish rhyolitic from quartz-latitic sources. Lanthanide ratios and Sr contents of calcites record the chemical evolution of waters flowing through the UZ and upper SZ. Variations in calcite chemistry in the UZ and in the barren zone show that (1) Sr, which is readily exchanged with clays or zeolites, is essentially removed from some flowpaths that are in contact with these minerals and (2) traces of Mn oxides found in the tuffs have a significant effect of groundwater chemistry in the UZ and in the barren zone by removing almost all Ce from solution (evidenced by characteristic Ce depletions in calcite throughout this zone). Extreme Ce removal may be a result of Ce oxidation (Ce 3+ → Ce 4+ ) at the surfaces of some Mn oxides, particularly rancieite. Higher Sr contents and lack of Ce depletions in the deeper Mn calcites reflect different ages, origins, and transport systems. The calcite record of lanthanide and Sr transport in the UZ shows that minor minerals (clays and zeolites) and even trace minerals (Mn oxides) will affect the compositions of groundwaters that flow over distances greater than a few tens of meters. 43 refs., 8 figs., 4 tabs

  18. In-situ test programs related to design and construction of high-level nuclear waste (HLW) deep geologic repositories. Final report (Task 2), June 1981-November 1982

    International Nuclear Information System (INIS)

    Roberds, W.; Bauhof, F.; Gonano, L.

    1983-03-01

    The media and sites considered include (1) basalt at Hanford, Washington; (2) tuff at Yucca Mountain, Nevada Test Site; (3) domal salt at specific Gulf Coast sites; (4) bedded salt at an unspecified site; and (5) granite at an unspecified site. A licensing perspective is outlined and a defensible rationale developed and utilized for the test selection process. This rationale essentially consists of: establishing the information needs for construction authorization; assessing the relevant capabilities of available tests; and matching the capabilities of specific tests to the perceived information needs. The information needs at any time consist of the additional information (if any) needed in order to predict satisfactory repository system performance with the required level of confidence, and thus are a function of: the significance of the repository engineered components and site characteristics to system performance; the currently available information, which may be supplemented with time; and the acceptable level of confidence in satisfactory performance for each licensing step. Determination of the acceptable levels of confidence and the significance of repository system components is outside the scope of this report. Suitable assumptions have thus been made regarding the development of information needs for construction authorization by the time of initial site submittals. Tests which are available and respond to the perceived media/site specific information needs, either by simulation or assessment of site characteristics, are identified and their capabilities assessed. Specific in situ tests are investigated and described in detail. Research and development which might be effective in improving test capabilities have been recommended

  19. Indications for Self-Sealing of a Cementitious L and ILW Repository

    Energy Technology Data Exchange (ETDEWEB)

    Pfingsten, W

    2001-07-01

    Repositories for low and intermediate level nuclear waste contain large amounts of cementitious material. As a consequence of the interaction with formation waters, the cement will be degraded forming secondary minerals. The amount of precipitating secondary minerals depends on the chemical composition of the formation water. Furthermore, in the vicinity of the repository the hydraulic conditions and the parameters describing mass (radionuclide) transport will change with time during the cement degradation phase. As a result, porosity changes due to mineral and cement reactions will influence permeability and diffusivity: formation water rich in CO{sub 2} will lead to calcite precipitation in the water conducting zones surrounding the cementitious waste repository and, therefore, will have an impact on the radionuclide release from the cementitious repository into the host rock environment. Laboratory column experiments showed concurrent porosity and permeability changes during degradation of porous cement discs. However, very different quantitative results have been observed when CO{sub 2}-rich or pure water were used. The sequentially coupled flow, transport and chemical reaction code, MCOTAC, is used to include such observations in the modelling. A porosity-permeability and a porosity-diffusivity relation are used for describing cement degradation and related secondary mineral precipitation. For these complex coupled processes one-dimensional modelling has reached its limits of applicability. Therefore, two-dimensional model calculations are used to predict the temporal evolution of transport parameters for radionuclides within a 'small scale' near-field of a cementitious waste repository. Mineral reactions influence hydraulic and transport parameters within such a near-field, causing reduced solute transport in the vicinity of the repository due to porosity and permeability changes at the rock-repository-interface. Also, the transport of radionuclides

  20. Preliminary estimate of the costs involved in the implantation of a low and medium level radioactive waste repository in Brazil

    International Nuclear Information System (INIS)

    Branco, Otavio E.A.; Carvalho Filho, Carlos A.; Ferreira, Vinicius V.M.; Alves, Paulo R.R.

    2009-01-01

    One relevant subject in the decision making process linked to the implantation of a low and intermediate level waste (LILW) repository in Brazil is regarding to the project expected costs. It is important to estimate in a solid way the total and partial costs expected, considering each one of the enterprise implantation phases. This work shows an initial estimative of these costs, based on reports and papers that evaluate the implantation, operation, closure and post closure costs of radioactive LILW waste repositories. In the development of this research only the costs regarding to near surface repositories, or similar ones, were considered. The total cost was estimated as approximately 115 million dollars, considering the whole project lifetime as 300 years. Considering the repository start-up costs (site selection, licensing, project and construction), the total value is estimated as 48 million dollars (1600 dollars/m 3 ). It is important to emphasize that some cares should be taken when costs obtained from the acquired experience by another countries in the repositories development are analyzed. As example, the costs for disposal 1 m 3 of low and medium level radioactive waste vary significantly from one country to another, even when repositories with similar projects are compared. Also the total costs of construction and licensing are significantly higher when compared those ones from 'conventional' facilities with similar technological characteristics. Finally, although about a dozen low and medium level radioactive waste repository are operating in Europe, new projects should be faced, as the international practice demonstrate, as original developments. (author)

  1. Initial design process of the repository

    International Nuclear Information System (INIS)

    Osmanlioglu, A.E.

    2001-01-01

    The concept of the final disposal of high level wastes is to isolate the waste from the biosphere for extremely long periods of time by emplacement of wastes into deep stable geological formations. Several geological formations have been considered as candidate host environments for high level waste disposal and several techniques have been developed for repository design. In this study, interrelationships of main parameters of a general repository design have been defined and effective parameters are shown at each step. Initial design process is based on the long term stability of underground openings as disposal galleries. For this reason, this design process includes two main analyses: mechanical analysis and thermal analysis. Each of the analysis systems is directly related to each other by technical precautions. As a result of this design process, general information about the acceptable depth of the repository, layout and emplacement pattern can be taken. Final design study can be established on the result of initial design process. (author)

  2. Augmenting interoperability across repositories architectural ideas

    CERN Multimedia

    CERN. Geneva

    2005-01-01

    The aDORe digital repository architecture designed and implemented by the Los Alamos Research Library is fully standards-based and highly modular, with the various components of the architecture interacting in a protocol-driven manner. Although aDORe was designed for use in the context of the Los Alamos Library, its modular and standards-based design has led to interesting insights regarding possible new levels of interoperability in a federation of heterogeneous repositories. The presentation will discuss these insights, and will illustrate that attractive federations of repositories can be built by introducing rather basic interoperability requirements. The presentation will also show that, once these requirements are met, a powerful service framework that overlays the federation can emerge.

  3. Reducing Psychological Resistance to Digital Repositories

    Directory of Open Access Journals (Sweden)

    Brian Quinn

    2010-06-01

    Full Text Available The potential value of digital repositories is dependent on the cooperation of scholars to deposit their work. Although many researchers have been resistant to submitting their work, the literature on digital repositories contains very little research on the psychology of resistance. This article looks at the psychological literature on resistance and explores what its implications might be for reducing the resistance of scholars to submitting their work to digital repositories. Psychologists have devised many potentially useful strategies for reducing resistance that might be used to address the problem; this article examines these strategies and how they might be applied.

  4. Developing criteria to establish Trusted Digital Repositories

    Science.gov (United States)

    Faundeen, John L.

    2017-01-01

    This paper details the drivers, methods, and outcomes of the U.S. Geological Survey’s quest to establish criteria by which to judge its own digital preservation resources as Trusted Digital Repositories. Drivers included recent U.S. legislation focused on data and asset management conducted by federal agencies spending $100M USD or more annually on research activities. The methods entailed seeking existing evaluation criteria from national and international organizations such as International Standards Organization (ISO), U.S. Library of Congress, and Data Seal of Approval upon which to model USGS repository evaluations. Certification, complexity, cost, and usability of existing evaluation models were key considerations. The selected evaluation method was derived to allow the repository evaluation process to be transparent, understandable, and defensible; factors that are critical for judging competing, internal units. Implementing the chosen evaluation criteria involved establishing a cross-agency, multi-disciplinary team that interfaced across the organization. 

  5. Modelling gas generation in radioactive waste repositories

    International Nuclear Information System (INIS)

    Agg, P.J.

    1992-07-01

    In a repository containing low- and intermediate-level waste, gas generation will occur principally by the coupled processes of metal corrosion and microbial degradation of cellulosic waste. This paper describes a mathematical model designed to address gas generation by these mechanisms. The metal corrosion model incorporates a three-stage process encompassing both aerobic and anaerobic corrosion regimes; the microbial degradation model simulates the activities of eight different microbial populations, which are maintained as functions both of pH and of the concentrations of particular chemical species. Gas concentrations have been measured over a period of three years in large-scale drum experiments designed to simulate repository conditions. Model predictions are confirmed against the experimental measurements, and a prediction is then made of gas concentrations and generation rates over an assessment period of one million years in a radioactive waste repository. (Author)

  6. Modelling gas generation in radioactive waste repositories

    International Nuclear Information System (INIS)

    Agg, P.J.

    1993-02-01

    In a repository containing low- and intermediate-level waste, gas generation will occur principally by the coupled processes of metal corrosion and microbial degradation of cellulosic waste. This Paper describes a mathematical model design to address gas generation by these mechanisms. The metal corrosion model incorporates a three-stage process encompassing both aerobic and anaerobic corrosion regimes; the microbial degradation model simulates the activities of eight different microbial populations, which are maintained as functions both of pH and of the concentrations of particular chemical species. Gas concentrations have been measured over a period of three years in large-scale drum experiments designed to simulate repository conditions. Model predictions are confirmed against the experimental measurements, and a prediction is then made of gas concentrations and generation rates over an assessment period of one million years in a radioactive waste repository. (author)

  7. Investigative study of standards for digital repositories and related services

    CERN Document Server

    Foulonneau, Muriel; Badolato, Anne-Marie

    2008-01-01

    This study is meant for institutional repository managers, service providers, repository software developers and generally, all players taking an active part in the creation of the digital repository infrastructure for e-research and e-learning. It reviews the current standards, protocols and applications in the domain of digital repositories. Special attention is being paid to the interoperability of repositories to enhance the exchange of data in repositories. It aims to stimulate discussion about these topics and supports initiatives for the integration of and, where needed, development of

  8. Groundwater drawdown as a factor in long-term repository performance assessment

    International Nuclear Information System (INIS)

    Legore, T.; Arnett, R.C.

    1985-03-01

    The production of a large scale hydraulic sink that could delay the movement of groundwater and nuclides away from potential basalt repository has been analyzed. Pumping of the flow tops of the Cohassett flow and underlying flow during the construction phase of the repository was modeled with the MAGNUM-3D computer code. The numerical results indicated that with water pumping rates approaching the expected flow capacity of the aquifers, the resulting hydraulic sink lasted for a time period of 60 to 600 years depending on the nature of the Cold Creek syncline boundaries (constant head versus no flow). The results do not support a conclusion that a practical, large-scale hydraulic sink would provide significant delay in movement of radionuclides away from a repository. The results of this analysis are not to be included in any site analysis supporting a license application or site selection. 13 refs., 9 figs., 1 tab

  9. Proposed format and content of environmental reports for deep geologic terminal repositories for radioactive material

    International Nuclear Information System (INIS)

    Carrell, D.J.; Jones, G.L.

    1978-01-01

    As the Nuclear Regulatory Commission has not yet issued a format guide for the preparation of an environmental impact statement for radioactive waste repositories, Rockwell Hanford operations has developed an annotated outline which will serve as the basis for the environmental evaluation activities until replaced by an appropriate NRC regulatory guide. According to the outline, the applicant should summarize the major environmental effects that are expected to occur during the construction, operation, and terminal isolation phases of the radioactive material repository. Compare these environmental effects with the possible effect of continued use of interim storage facilities. Unless unforeseen environmental effects become apparent, the summary should be a positive statement indicating that the short-term environmental effects are outweighed by the long-term benefits of the repository

  10. Morsleben repository - Interdependence of technical feasibility and functionality of geotechnical barriers and safety case development

    International Nuclear Information System (INIS)

    Wollrath, Juergen; Mauke, Ralf; Mohlfeld, Matthias; Niemeyer, Matthias; Becker, Dirk-Alexander

    2014-01-01

    Based on a selection procedure whereby ten existing mines had been taken into consideration, the Morsleben repository for radioactive waste (ERAM) was built in a former mine for potash and rock salt production. The specific concerns and objectives of a repository for radioactive waste could not be taken into account when the mine was built at the beginning of the last century. Irrespective of this, altogether about 37 000 m 3 of low-level and intermediate-level radioactive waste was stored in several areas of the mine between 1971 and 1991 and from 1994 to 1998. In the scope of the ongoing licensing procedure, the safety of the 'historically grown' repository needs to be demonstrated for the phase after it has been sealed. (authors)

  11. Source terms for analysis of accidents at a high level waste repository

    International Nuclear Information System (INIS)

    Mubayi, V.; Davis, R.E.; Youngblood, R.

    1989-01-01

    This paper describes an approach to identifying source terms from possible accidents during the preclosure phase of a high-level nuclear waste repository. A review of the literature on repository safety analyses indicated that source term estimation is in a preliminary stage, largely based on judgement-based scoping analyses. The approach developed here was to partition the accident space into domains defined by certain threshold values of temperature and impact energy density which may arise in potential accidents and specify release fractions of various radionuclides, present in the waste form, in each domain. Along with a more quantitative understanding of accident phenomenology, this approach should help in achieving a clearer perspective on scenarios important to preclosure safety assessments of geologic repositories. 18 refs., 3 tabs

  12. Mineralogy, origin and commercial value of the zeolite-rich tuffs in the Petrota-Pentalofos area, Evros County, Greece

    Directory of Open Access Journals (Sweden)

    Walsh, J. N.

    1998-04-01

    Full Text Available The zeolite-rich tuffs of the Petrota-Pentalofos area were deposited in the Arrestees Basin during the Eocene. They are up to 100 m thick and extend more than 15 Km in a long axis. Most of the outcrops consist of frequent alternations of very fine grained tuff with pumice and lapel tuffs, the latter containing detrital fragments of the Mesozoic substrate of the basin. X-ray Diffraction, Scanning Electron Microscopy and light microscopy analysis on quarry and borehole samples has shown that the tuffs are composed mainly of clinoptilolite and minor cristobalite, with a small proportion of detrital constituents (quartz, mica-schist and pyrogenic crystals (feldspars, quartz, biotite. Minor amounts of mordenite randomly occur in some of the northern outcrops, closer to the occurrences of lava. ICP-AES chemical analysis of the tuffs gives evidence that the original magmas were of quartz-latite composition. The tuffs rest on pre-Cenozoic metamorphic basement and pass gradationally upwards into sandstone and limestone. Evidence is given for deposition of the tuffs in a supra to infra-littoral environment. The zeolitic tuffs originated as epiclastic volcanic sediments, transported by water from the source of the eruption. The transformation of the volcanic glass of the tuffs to zeolite and cristobalite has taken place by meteoric waters in an open hydrological system existed during the Tertiary. The zeolitic rocks are currently being exploited as an animal feed supplement.Las tobas ricas en cebollitas del área de Petrota-Pentalofos se depositaron en la cuenca de Orejitas durante el Doceno. Alcanzan 100 m de potencia y superan los 15 km de extensión longitudinal. La mayoría de los afloramientos consisten en alternancias de toba de grano muy fino y toba de pómez y lapilli con fragmentos detritos del sustrato Mesozoico de la cuenca. Análisis por difamación de rayos X, microscopía electrónica de barrido y microscopía óptica en muestras de mano y de

  13. Citizen participation in nuclear waste repository siting

    International Nuclear Information System (INIS)

    Howell, R.E.; Olsen, D.

    1982-12-01

    The following study presents a proposed strategy for citizen participation during the planning stages of nuclear waste repository siting. It discusses the issue from the general perspective of citizen participation in controversial issues and in community development. Second, rural institutions and attitudes toward energy development as the context for developing a citizen participation program are examined. Third, major citizen participation techniques and the advantages and disadvantages of each approach for resolving public policy issues are evaluated. Fourth, principles of successful citizen participation are presented. Finally, a proposal for stimulating and sustaining effective responsible citizen participation in nuclear waste repository siting and management is developed

  14. Overview of the current CRWMS repository design

    International Nuclear Information System (INIS)

    Daniel, R.B.; Teraoka, G.M.

    1998-01-01

    This paper summarizes the current design for a potential geologic repository for spent fuels and high-level wastes at Yucca Mountain, Nevada. The objective of the paper is to present the key design features of the Mined Geologic Disposal System (MGDS) surface facilities and MGDS subsurface facilities. The paper describes the following: surface layout; waste handling operations design; subsurface design; and the underground transport and emplacement design. A more detailed presentation of key features is provided in the ''Reference design description for a geologic repository'' which is located on the YMP Homepage at www.ymp.gov

  15. Mineralogy and clinoptilolite K/Ar results from Yucca Mountain, Nevada, USA: A potential high-level radioactive waste repository site

    International Nuclear Information System (INIS)

    WoldeGabriel, G.; Broxton, D.E.; Bish, D.L.; Chipera, S.J.

    1993-11-01

    The Yucca Mountain Site Characterization Project is investigating Yucca Mountain, Nevada, as a potential site for a high-level nuclear waste repository. An important aspect of this evaluation is to understand the geologic history of the site including the diagenetic processes that are largely responsible for the present-day chemical and physical properties of the altered tuffs. This study evaluates the use of K/Ar geochronology in determining the alteration history of the zeolitized portions of Miocene tuffs at Yucca Mountain. Clinoptilolite is not generally regarded as suitable for dating because of its open structure and large ion-exchange capacity. However, it is the most abundant zeolite at Yucca Mountain and was selected for this study to assess the feasibility of dating the zeolitization process and/or subsequent processes that may have affected the zeolites. In this study we examine the ability of this mineral to retain all or part of its K and radiogenic Ar during diagenesis and evaluate the usefulness of the clinoptilolite K/Ar dates for determining the history of alteration

  16. Evaluation of geochemical properties used in area-to-location screening for a nuclear waste repository at the Nevada Test Site

    International Nuclear Information System (INIS)

    Purson, J.D.

    1983-03-01

    The area-to-location screening of a potential site for a nuclear waste repository is dependent on geologic compatibility. Specifically, the geochemical properties of candidate locations are significant in the overall site evaluation. This report describes three geochemical factors or attributes and their application to an area-to-location screening of the southwestern quadrant of the Nevada Test Site and contiguous areas. These are only 3 of 31 attributes examined in the screening process. Geochemical and rock media considerations relevant to site screening include: (1) retardation by hydraulics - a study of ground-water movement through fractures vs a permeable matrix; (2) thermal stability of minerals - a measurement of undesirable mineral assemblages in the rock; and (3) retardation by sorption - an evaluation of the total sorptive capacity at a location, based on stratigraphy and lithology. Twelve potential host rocks situated in 20 locations are examined; 2 of these have consistently fewer favorable characteristics, and 6 others have generally fewer favorable characteristics than the 4 remaining rock units. The four units that appear most favorable by geochemical measures are the tuffaceous beds of Calico Hills, granite intrusives, the densely welded Topopah Spring tuff, and the Crater Flat Tuff at Yucca Mountain

  17. Development Support Environment of Business ApplicationsBased on a Multi-Grain-Size Repository

    Science.gov (United States)

    Terai, Koichi; Izumi, Noriaki; Yamaguchi, Takahira

    In order to build the Web-based application as a shopping site on the Web, various ideas from the different viewpoints are required, such as enterprise modeling, workflow modeling, software development, and so on. From the above standpoint, this paper proposes an integrated environment to support the whole development process of analysis, design and implementation of business application. In order to reuse know-hows of various ideas in the business application development, we device a multi-grain-size repository, which consists of coarse-, middle-, and fine-grain-size repositories that correspond to the enterprise models, workflow models, and software models, respectively. We also provide a methodology that rebuilds heterogeneous information resources required for the business applications development into a multi-grain-size repository based on ontologies. The contents of the repositories are modeled by the is-a, has-a, and E-R relations, and described by the XML language. We have implemented Java-based prototype environment with the tools dealing with the multi-layered repository and confirmed that it supports us in various phases of business application development including business model manifestation, detailed business model definition and an implementation of business software applications.

  18. Study of cesium sorption in Brazilian clays for their utilization as engineering barrier in repository

    International Nuclear Information System (INIS)

    Freire, Carolina B.; Tello, Cledola Cassia O. de

    2013-01-01

    The radioactive wastes require suitable and safe management from beginning of their generation until the storage in repository. The backfill layer is considered one of the most important components of the engineering barrier of the repository. As CNEN is presently implementing a repository for low and intermediate level wastes, named RBMN project, the results obtained with this research may be applied in the future, during the phases of elaboration of the repository conceptual design. Therefore, is important to know the properties of different materials that can be used as backfill layer. The objective of this research was to characterize some Brazilian clays in order to evaluate the viability of their use in the backfill layer, one of the radioactive waste repository barriers. The main function of this barrier is to contribute in the delay of the radionuclides movement, and to prevent their release into the environment. Four clays provided by national suppliers were selected for the research: Ca-Bentonite, Na-Bentonite, Kaolinite and Vermiculite. Their physical, chemical and mineralogical characteristics were determined, and also their sorption potential of Cesium cation. In accordance to Freundlich and Langmuir models the Vermiculite was the best sorbers of cesium. The clays presented the n value of the Freundlich model different of 1, that mean heterogenic sorption or that the clays present sorption regions of different energy. From the results was possible to conclude that the Vermiculite clay contain regions of sorption higher energy. (author)

  19. Open DOAR the Directory of Open Access Repositories

    CERN Multimedia

    CERN. Geneva

    2005-01-01

    The last year has seen wide-spread growth in the idea of using open access repositories as a part of a research institution's accepted infrastructure. Policy development from institutions and funding bodies has also supported the growth of the repository network. The next stage of expansion will be in the provision of services and cross-repository facilities and resources. Of course, it is hoped that these will then establish a feed-back loop to encourage repository population and further repository establishment, as the potential of open access to research materials is realised. The growth of repositories has been organic, with a variety of different repositories based in departments, institutions, funding agencies or subject communities, with a range of content, both in type and subject. Existing repositories are expanding their holdings, from eprints to associated research data-sets, or with learning objects and multimedia material. This presentation will look at the development of the Directory of Open Ac...

  20. Visual querying and analysis of large software repositories

    NARCIS (Netherlands)

    Voinea, Lucian; Telea, Alexandru

    We present a software framework for mining software repositories. Our extensible framework enables the integration of data extraction from repositories with data analysis and interactive visualization. We demonstrate the applicability of the framework by presenting several case studies performed on