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Sample records for chalk river laboratories

  1. Anthropogenic radionuclides in Ottawa River sediment near Chalk River Laboratories

    International Nuclear Information System (INIS)

    The Ottawa River has received nuclear reactor effluent from Chalk River Laboratories (CRL) for more than 60 years, including releases from a NRX accident in 1952. Recent interest in the potential impact of these historical releases and the possible need for remediation of a small region immediately downstream from the release point has led to comprehensive studies to assess risk to people and wildlife. In this paper, the results of an extensive survey of gamma-emitting anthropogenic radionuclides in Ottawa River sediment in the vicinity of CRL are presented. Anthropogenic radionuclides detected in Ottawa River sediment include 60Co, 94Nb, 137Cs, 152Eu, 154Eu, 155Eu and 241Am. Concentrations of all anthropogenic radionuclides decline rapidly with distance downstream of the process outfall, reaching stable concentrations about 2 km downstream. All of these radionuclides are found at some sites within 2 km upstream of the process outfall suggesting limited upstream transport and sedimentation. Comparison of anthropogenic radionuclides with several representative primordial radionuclides shows that with the exception of sites at the process outfall and within 2 km downstream of the process outfall, primordial radionuclide concentrations greatly exceed CRL derived anthropogenic radionuclide concentrations. Thus, over 60 years of radionuclide releases from operations at CRL have had little impact on radionuclide concentrations in Ottawa River sediment, except at a few sites immediately adjacent to the process outfall. (author)

  2. Recent developments in waste characterization at Chalk River Nuclear Laboratories

    International Nuclear Information System (INIS)

    The waste characterization program (WCP) at Chalk River Nuclear Laboratories (CRNL) was initiated in 1982 to determine the physical, chemical and radiological properties of wastes intended for disposal in IRUS (Intrusion Resistant Underground Structure), a belowground vault to be constructed at CRNL. During the last year, work on the WCP has centered on determining the radionuclide inventories in candidate wastes for IRUS by gamma-ray monitoring and destructive radiochemical analysis. This paper presents the technical problems associated with monitoring various waste forms (geometry considerations, shielding problems, operating environment, etc.) and also presents details of the destructive radiochemical analysis program

  3. Advanced fuel cycle development at Chalk River Laboratories

    International Nuclear Information System (INIS)

    Chalk River Laboratories (CRL) has a mandate from the Canadian government to develop nuclear technologies that support generation of clean, safe energy. This includes the development of advanced nuclear fuel technologies to ensure sustainable energy sources for Canadians. The Fuel Development Branch leads CRL's development of advanced nuclear-reactor fuels. CRL capabilities include fuel fabrication development, irradiation testing, post-irradiation examination (PIE), materials characterization and code development (modeling). This paper provides an overview of these capabilities and describes recent development activities that support fuel-cycle flexibility in heavy-water reactors. This includes a review of irradiation testing and PIE for mixed-oxide, thoria, high-burnup UO2 and low-void reactivity fuels and burnable neutron absorbers. Fabrication development, material characterizations and modeling associated with these tests are also described. (author)

  4. Molten fuel moderator interaction program at Chalk River Laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Nitheanandan, T.; Kyle, G.; O' Connor, R.; Sanderson, D.B. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2006-12-15

    The Canadian nuclear power generation industry, represented by the CANDU Owners Group (COG), has been funding an experimental program at Chalk River Laboratories (CRL) to study the interaction between molten material ejected from a fuel channel and the moderator. These experiments were designed to address one of the very low probability postulated accident events considered for CANDU Pressurized Heavy Water Reactors. The reactor consists of an array of horizontal fuel channels that contain the UO{sub 2}, nuclear fuel and high-temperature, high-pressure heavy water coolant. Under severely restricted flow blockage conditions, approaching 100% reduction of the flow area, postulated in a fuel channel, the temperature excursion could result in fuel melting, consequential failure of the fuel channel, and ejection of the molten fuel at high pressures into the heavy water moderator at near atmospheric pressure. In preparation for these tests, a chemical mixture called a thermite, that could produce a simulated molten fuel when ignited, was developed in partnership with Argonne National Laboratory (USA). Following this thermite development, two base-case reference tests were completed. The two base-case reference tests, with no molten material present, were performed in the Molten-Fuel Moderator-Interaction (MFMI) facility at CRL. Following the base-case reference tests, a high-pressure melt ejection test using prototypical corium was conducted. The objectives of this paper are to provide an overview of the MFMI program and present the results obtained from thermite development, base-case and melt ejection experiments. (author)

  5. Molten fuel moderator interaction program at Chalk River Laboratories

    International Nuclear Information System (INIS)

    The Canadian nuclear power generation industry, represented by the CANDU Owners Group (COG), has been funding an experimental program at Chalk River Laboratories (CRL) to study the interaction between molten material ejected from a fuel channel and the moderator. These experiments were designed to address one of the very low probability postulated accident events considered for CANDU Pressurized Heavy Water Reactors. The reactor consists of an array of horizontal fuel channels that contain the UO2, nuclear fuel and high-temperature, high-pressure heavy water coolant. Under severely restricted flow blockage conditions, approaching 100% reduction of the flow area, postulated in a fuel channel, the temperature excursion could result in fuel melting, consequential failure of the fuel channel, and ejection of the molten fuel at high pressures into the heavy water moderator at near atmospheric pressure. In preparation for these tests, a chemical mixture called a thermite, that could produce a simulated molten fuel when ignited, was developed in partnership with Argonne National Laboratory (USA). Following this thermite development, two base-case reference tests were completed. The two base-case reference tests, with no molten material present, were performed in the Molten-Fuel Moderator-Interaction (MFMI) facility at CRL. Following the base-case reference tests, a high-pressure melt ejection test using prototypical corium was conducted. The objectives of this paper are to provide an overview of the MFMI program and present the results obtained from thermite development, base-case and melt ejection experiments. (author)

  6. Contaminated groundwater characterization at the Chalk River Laboratories, Ontario, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Schilk, A.J.; Robertson, D.E.; Thomas, C.W.; Lepel, E.A. [Pacific Northwest National Lab., Richland, WA (United States); Champ, D.R.; Killey, R.W.D.; Young, J.L.; Cooper, E.L. [Chalk River Labs., Chalk River, Ontario (Canada)

    1993-03-01

    The licensing requirements for the disposal of low-level radioactive waste (10 CFR 61) specify the performance objectives and technical requisites for federal and commercial land disposal facilities, the ultimate goal of which is to contain the buried wastes so that the general population is adequately protected from harmful exposure to any released radioactive materials. A major concern in the operation of existing and projected waste disposal sites is subterranean radionuclide transport by saturated or unsaturated flow, which could lead to the contamination of groundwater systems as well as uptake by the surrounding biosphere, thereby directly exposing the general public to such materials. Radionuclide transport in groundwater has been observed at numerous commercial and federal waste disposal sites [including several locations within the waste management area of Chalk River Laboratories (CRL)], yet the physico-chemical processes that lead to such migration are still not completely understood. In an attempt to assist in the characterization of these processes, an intensive study was initiated at CRL to identify and quantify the mobile radionuclide species originating from three separate disposal sites: (a) the Chemical Pit, which has received aqueous wastes containing various radioisotopes, acids, alkalis, complexing agents and salts since 1956, (b) the Reactor Pit, which has received low-level aqueous wastes from a reactor rod storage bay since 1956, and (c) the Waste Management Area C, a thirty-year-old series of trenches that contains contaminated solid wastes from CRL and various regional medical facilities. Water samples were drawn downgradient from each of the above sites and passed through a series of filters and ion-exchange resins to retain any particulate and dissolved or colloidal radionuclide species, which were subsequently identified and quantified via radiochemical separations and gamma spectroscopy. These groundwaters were also analyzed for anions

  7. Waste management activities at Chalk River Nuclear Laboratories

    International Nuclear Information System (INIS)

    Low-level radioactive waste-management operations at the Chalk River Nuclear Laboratories (CRNL) of Atomic Energy of Canada Limited began in 1946 and currently include waste processing and interim storage in engineered facilities built in unsaturated sandy overburden. In addition, an R and D program has been underway for about ten years directed at preparations for a transition from the current storage mode to one of permanent disposal for the management of about 5000 m3/a (as-generated volume) of low- and intermediate-level solid wastes generated on the CRNL site or shipped there from the nuclear industry, radioisotope producers and users across Canada. The first phase of the disposal program was the development and demonstration of selected waste processing methods for the volume reduction and immobilization of solid and liquid low-level wastes. This phase is now nearing completion with the construction, commissioning and operation of the CRNL Waste Treatment Centre. The Centre consists of a controlled-air incinerator for combustible solid and liquid wastes, ultrafiltration, reverse-osmosis, and evaporator systems for aqueous wastes, and wipe-film and ribbon-blender bituminizers for immobilizing the ash and waste concentrates. The second phase of the program is directed at further advances in waste characterization and processing, and at the development of two disposal concepts potentially suitable for the local geological situation - Intrusion-resistant shallow land burial and excavated rock cavities at shallow depth. Also included is the preparation of safety-assessment methodologies for the two concepts. The intent is to carry one or both disposal concepts through the constriction and operation of prototype facilities at CRNL as a qualified component of an evolving integrated disposal strategy for the current inventory and future arisings of wastes to be managed

  8. Inventory of radioactivity in Ottawa River-bed sediments near the Chalk River Laboratories

    International Nuclear Information System (INIS)

    AECL's Chalk River Laboratories (CRL) are situated on the Ontario side of the Ottawa River about 200 km NW of the City of Ottawa. Since 1947, water for cooling CRL's research reactors has been piped from and returned to the Ottawa River. From 1952 to the present time, cooling water has been discharged through the Process Sewer at a rate of 1.5 to 2 m3/s. The Outfall, which is the discharge from the Process Sewer, is in 18 m of water, 65 m offshore. Flow is directed toward the river surface through three 'diffuser vents,' creating a turbulent swirl at the surface and maintaining a patch of open water in winter. In addition to cooling water, the Outfall has, over the years, included small additional effluents from a heavy water recovery plant, a decontamination centre and a waste treatment centre. Although the effluent has been monitored and has met applicable regulatory requirements, investigations of the riverbed near the Outfall revealed radioactivity. In 2001, a riverbed reconnaissance and a detailed coring program were initiated for the purpose of determining the inventory of residual radioactivity. (author)

  9. Edibility of sport fishes in the Ottawa River near Chalk River Laboratories

    International Nuclear Information System (INIS)

    To address the question of edibility of fish in the Ottawa River near Chalk River Laboratories (CRL), 123 game fish were collected for analysis from four locations: Mackey and Rolphton (45 km and 35 km upstream of Chalk River Laboratories (CRL), respectively), the Sandspit (Pointe au Bapteme) and Cotnam Island (1.6 km and 45 km downstream of CRL, respectively). Twenty-six to thirty-six game fish were collected at each location in 2007 and samples of flesh or bone were analyzed. Trap nets were used to collect only the fish required, allowing release of management-sensitive species. The focus was on walleye (Sander vitreus) because they are abundant and popular among anglers. A few northern pike (Esox lucius) and a smaller number of smallmouth bass (Micropterus dolomieui) were also collected at three of the four sites. Samples of the fish were analyzed for cesium-137 (137Cs), strontium-90 (90Sr), mercury (Hg), and selected organo-chlorine compounds. Concentrations of 137Cs in the flesh and 90Sr in the bones of sport fish were low and similar at all four locations and appear to reflect the global residuals from nuclear weapons testing (primarily in the 1960's) as opposed to releases from CRL. Possible explanations are: 1) Reductions in radionuclide releases from CRL in recent decades and 2) Relatively large foraging ranges of sport fish. Mercury concentrations were elevated in fishes in the Ottawa River and were significantly higher at the Sandspit and Rolphton than at Mackey and Cotnam Island (p<0.001). Mercury concentrations from the four sites are comparable to concentrations in other Ontario and Quebec lakes. It is advisable therefore, that consumers follow the fish consumption guidelines issued by provincial authorities when eating fish from the Ottawa River. Organo-chlorine compounds were not detected in walleye; however, they were detected in all eight of the pike collected at Cotnam Island. The highest organo-chlorine concentrations were measured in two of the

  10. Edibility of sport fishes in the Ottawa River near Chalk River Laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Lee, D.R.; Chaput, T.; Miller, A.; Wills, C.A., E-mail: leed@aecl.ca [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2013-12-15

    To address the question of edibility of fish in the Ottawa River near Chalk River Laboratories (CRL), 123 game fish were collected for analysis from four locations: Mackey and Rolphton (45 km and 35 km upstream of Chalk River Laboratories (CRL), respectively), the Sandspit (Pointe au Bapteme) and Cotnam Island (1.6 km and 45 km downstream of CRL, respectively). Twenty-six to thirty-six game fish were collected at each location in 2007 and samples of flesh or bone were analyzed. Trap nets were used to collect only the fish required, allowing release of management-sensitive species. The focus was on walleye (Sander vitreus) because they are abundant and popular among anglers. A few northern pike (Esox lucius) and a smaller number of smallmouth bass (Micropterus dolomieui) were also collected at three of the four sites. Samples of the fish were analyzed for cesium-137 ({sup 137}Cs), strontium-90 ({sup 90}Sr), mercury (Hg), and selected organo-chlorine compounds. Concentrations of {sup 137}Cs in the flesh and {sup 90}Sr in the bones of sport fish were low and similar at all four locations and appear to reflect the global residuals from nuclear weapons testing (primarily in the 1960's) as opposed to releases from CRL. Possible explanations are: 1) Reductions in radionuclide releases from CRL in recent decades and 2) Relatively large foraging ranges of sport fish. Mercury concentrations were elevated in fishes in the Ottawa River and were significantly higher at the Sandspit and Rolphton than at Mackey and Cotnam Island (p<0.001). Mercury concentrations from the four sites are comparable to concentrations in other Ontario and Quebec lakes. It is advisable therefore, that consumers follow the fish consumption guidelines issued by provincial authorities when eating fish from the Ottawa River. Organo-chlorine compounds were not detected in walleye; however, they were detected in all eight of the pike collected at Cotnam Island. The highest organo

  11. A description of the tritium facility at the Chalk River Laboratories

    International Nuclear Information System (INIS)

    AECL's Tritium Facility is located at its Chalk River Laboratories (CRL). The Tritium Facility was originally built to support the tritium technology needs for CANDU reactors and Canadian fusion program. The Tritium Facility commenced its operation in 1979. Since its inception, it has been involved in the development of heavy water detritiation and upgrading processes, development and testing of tritium-breeder materials and design and testing of fusion-fuel cleanup systems for fusion reactor applications, investigation of tritium-materials interactions, tritium storage getters etc. The Tritium Facility also contributed to the design, construction and commissioning activities of the Combined Electrolysis and Catalytic Exchange Upgrading and Detritiation (CECE-UD) Facility at CRL and the Wolsong Tritium Removal Facility (WTRF) in Korea. This paper describes the general set-up of the laboratory, its capabilities and the current tritium-related activities. (author)

  12. Organically bound tritium (OBT) in soil at different depths around Chalk River Laboratories (CRL), Canada

    International Nuclear Information System (INIS)

    Atomic Energy of Canada Limited (AECL) Chalk River Laboratories (CRL) is a large nuclear research and test establishment with nuclear and non-nuclear facilities located in Chalk River, Ontario. The CRL Environmental Monitoring Program is designed to demonstrate that radiological exposure resulting from releases from the CRL site remain below the public dose limit specified in the regulations (1 mSv/year). This study was conducted to consolidate environmental effects following a continuous atmospheric tritium release observed at CRL. Soil samples were collected at depths of up to 20 cm using soil probes at the CRL site and surrounding areas. The samples were sectioned at 5 cm intervals, and HTO and OBT concentrations were measured in the samples. Prevailing winds at CRL are from NW and SE, which was suggested to be in close relationship with tritium distribution in environmental samples such as soils and plant leaves. The HTO concentration was the highest in surface soil water and plant leaves at a given sampling point. This result suggests that the concentration of tritium in surface soil water and in plants tissue free water essentially reflects the surrounding atmospheric tritium concentration. OBT concentrations in soil were measured at the historical HT release site, Plant Road, Mattawa Road and three background sites near CRL. The top layer of soil generally had the highest OBT concentration among collected soil samples. This result suggests that OBT concentrations are different from HTO concentrations at the same site and can be representative of previously released environmental tritium at the sampling point. The relationship between the OBT concentration in soil and the amount of tritium released into the environment will be useful for the evaluation of environmental tritium effects and the fate of tritium in the terrestrial ecosystem. The study points out that HTO shows shorter-term dynamic conditions, whereas OBT shows longer-term steady-state conditions

  13. Drivers of abundance and community composition of benthic macroinvertebrates in Ottawa River sediment near Chalk River Laboratories

    International Nuclear Information System (INIS)

    The Ottawa River has received effluent from Chalk River Laboratories (CRL) for more than 60 years. Some radionuclides and contaminants released in effluents are bound rapidly to particles and deposited in bottom sediments where they may be biologically available to benthic invertebrates and other aquatic biota. As part of a larger ecological assessment, we assess the potential impact of contaminated sediments in the vicinity of CRL on local benthic community structure. Using bivariate and multivariate approaches, we demonstrate that CRL operations have had little impact on the local benthic community. Despite elevated anthropogenic radionuclide activity concentrations in sediment near CRL's process outfall, the benthic community is no less abundant or diverse than what is observed upstream at background levels. The Ottawa River benthic invertebrate community is structured predominantly by natural physical and biological conditions in the sediment, specifically sediment water content and organic content. These natural habitat conditions have a stronger influence on macroinvertebrate communities than sediment contamination. (author)

  14. Drivers of abundance and community composition of benthic macroinvertebrates in Ottawa River sediment near Chalk River Laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Bond, M.J.; Rowan, D.; Silke, R.; Carr, J., E-mail: bondm@aecl.ca [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2013-12-15

    The Ottawa River has received effluent from Chalk River Laboratories (CRL) for more than 60 years. Some radionuclides and contaminants released in effluents are bound rapidly to particles and deposited in bottom sediments where they may be biologically available to benthic invertebrates and other aquatic biota. As part of a larger ecological assessment, we assess the potential impact of contaminated sediments in the vicinity of CRL on local benthic community structure. Using bivariate and multivariate approaches, we demonstrate that CRL operations have had little impact on the local benthic community. Despite elevated anthropogenic radionuclide activity concentrations in sediment near CRL's process outfall, the benthic community is no less abundant or diverse than what is observed upstream at background levels. The Ottawa River benthic invertebrate community is structured predominantly by natural physical and biological conditions in the sediment, specifically sediment water content and organic content. These natural habitat conditions have a stronger influence on macroinvertebrate communities than sediment contamination. (author)

  15. Decommissioning Experience: Chalk River, Canada

    International Nuclear Information System (INIS)

    Full text: Atomic Energy of Canada Limited has reported that work has continued on the decommissioning of old structures on the Chalk River laboratory site. An environmental assessment was approved in 2006 for the decommissioning of the NRX reactor fuel bays (A and B). The regulator approved two work packages for the removal of water and the wooden structure over the bays. The A bays were cleaned as far as possible and were emptied in 2007. Decontamination work will continue. Sections of the B bays were filled with sand and other parts filled with water. NRX is currently in storage (i.e. a dormant state) with surveillance. (author)

  16. Development of an Integrated Waste Plan for Chalk River Laboratories - 13376

    International Nuclear Information System (INIS)

    To further its Strategic Planning, the Atomic Energy of Canada Limited (AECL) required an effective approach to developing a fully integrated waste plan for its Chalk River Laboratories (CRL) site. Production of the first Integrated Waste Plan (IWP) for Chalk River was a substantial task involving representatives from each of the major internal stakeholders. Since then, a second revision has been produced and a third is underway. The IWP remains an Interim IWP until all gaps have been resolved and all pathways are at an acceptable level of detail. Full completion will involve a number of iterations, typically annually for up to six years. The end result of completing this process is a comprehensive document and supporting information that includes: - An Integrated Waste Plan document summarizing the entire waste management picture in one place; - Details of all the wastes required to be managed, including volume and timings by waste stream; - Detailed waste stream pathway maps for the whole life-cycle for each waste stream to be managed from pre-generation planning through to final disposition; and - Critical decision points, i.e. decisions that need to be made and timings by when they need to be made. A waste inventory has been constructed that serves as the master reference inventory of all waste that has been or is committed to be managed at CRL. In the past, only the waste that is in storage has been effectively captured, and future predictions of wastes requiring to be managed were not available in one place. The IWP has also provided a detailed baseline plan at the current level of refinement. Waste flow maps for all identified waste streams, for the full waste life cycle complete to disposition have been constructed. The maps identify areas requiring further development, and show the complexities and inter-relationships between waste streams. Knowledge of these inter-dependencies is necessary in order to perform effective options studies for enabling

  17. Groundwater monitoring and plume discharge zone characterization for the NRX radiostrontium plume at Chalk River Laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Olfert, J.M.; Audet, M.; Killey, D., E-mail: olfertjm@aecl.ca [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2013-12-15

    Groundwater is the principal pathway for the migration of most radiological and non-radiological compounds from past and present operating areas at Atomic Energy of Canada Limited's Chalk River Laboratories (CRL). The CRL Groundwater Monitoring Program (GWMP) was established to measure the groundwater quality around the perimeters of areas affected, or potentially affected, by groundwater plumes. One of these is the NRX Rod Bays plume, a legacy plume that originated from the fuel storage bays of the National Research Experimental (NRX) reactor. This plume contains primarily {sup 90}Sr migrating along the groundwater flow system to the Ottawa River. A characterization study of the shoreline region was completed recently to map the plume discharge zone by collecting samples from mini-piezometers and groundwater seeps (springs) during a period of low river level. Analysis of discharging groundwaters determined that the {sup 90}Sr concentrations were very similar to those sampled from nearby (upgradient) GWMP monitoring wells. With this favorable correlation, the high density of seep and mini-piezometer sampling along the shoreline allowed refinements to be made in defining the northerly and southerly boundaries of the radiostrontium plume. The seep and mini-piezometer sampling also provided evidence that the monitoring wells sampled routinely within the CRL GWMP are positioned appropriately for providing representative sampling of the plume. Shoreline seep and mini-piezometer sampling can lead to refinements in the conceptual site model for plumes with limited effort and cost. The supplemental characterization work can also potentially identify other targets for routine groundwater monitoring. (author)

  18. Overview of research in physics and health sciences at the Chalk River Nuclear Laboratories

    International Nuclear Information System (INIS)

    Toxicology research was a logical extension of existing program at Chalk River. Research in radiotoxicology has been going on there since the early forties. An overview of the existing physics and health sciences research programs operating at the Research Company of Atomic Energy of Canada Limited was presented. Programs in nuclear physics, heavy ion nuclear physics, astrophysical neutrino physics, condensed matter physics, fusion, biology, dosimetry, and environmental sciences were briefly described. In addition, a description of the research company organization was provided

  19. Post-irradiation examination of the 37M fuel bundle at Chalk River Laboratories (AECL)

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, J. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Daniels, T. [Ontario Power Generation, Pickering, Ontario (Canada); Montin, J. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2014-03-15

    The modified (-element (37M) fuel bundle was designed by Ontario Power Generation (OPG) to improve Critical Heat Flux (CHF) performance in ageing pressure tubes. A modification of the conventional 37-element fuel bundle design, the 37M fuel bundle allows more coolant flow through the interior sub-channels by way of a smaller central element. A demonstration irradiation (DI) of thirty-two fuel bundles was completed in 2011 at OPG's Darlington Nuclear Generating Station to confirm the suitability of the 37M fuel bundles for full core implementation. In support of the DI, fuel elements were examined in the Chalk River Laboratories Hot Cells. Inspection activities included: Bundle and element visual examination; Bundle and element dimensional measurements; Verification of bundle and element integrity; and Internal Gas Volume Measurements. The inspection results for 37M were comparable to that of conventional 37-element CANDU fuel. Fuel performance parameters of the 37M DI fuel bundle and fuel elements were within the range observed for similarly operated conventional 37-element CANDU fuel. Based on these Post Irradiation Examination (PIE) results, 37M fuel performed satisfactorily. (author)

  20. An overview of the waste characterization program at Chalk River Nuclear Laboratories

    International Nuclear Information System (INIS)

    In the last five years, Chalk River Nuclear Laboratories (CRNL) placed 17,000 m3 of wastes into storage (excluding contaminated soil and fill). Almost half of the waste was generated off-site. CRNL is now developing IRUS, an Intrusion Resistant Underground Structure, and the IST, an Improved Sand Trench, to replace storage with safe, permanent disposal. IRUS will be used to dispose of wastes with radiologically hazardous lifetimes between 150 and 500 years duration and the IST will be used for wastes with radiologically hazardous lifetimes of less than 150 years. A comprehensive Waste Characterization Program (WCP) is in place to support disposal projects. The WCP is responsible for (1) specifying the manifests for waste shipments; (2) developing and maintaining central databases for waste inventories and analytical data; and (3) developing the technologies and procedures to characterize the radiological and the physical/chemical properties of wastes. WCP work is being performed under the umbrella of a newly developed waste management quality assurance (QA) program. This paper gives an overview of the WCP with an emphasis on the requirements for determining radionuclide inventories in wastes, for implementing record-keeping systems and for maintaining a QA program for disposal operations

  1. MAGS low level waste storage at Atomic Energy of Canada Limited's Chalk River Laboratories

    International Nuclear Information System (INIS)

    The recent introduction of Modular Above Ground Storage (MAGS) constitutes a substantial improvement in the way solid Low-Level Radioactive Waste (LLRW) is handled and stored at AECL's Chalk River Laboratories (CRL). The LLRW generally contains items such as lightly contaminated clothing, paper towels, glassware, used equipment and building materials produced at CRL, or received from Canadian hospitals, universities and other waste generators. These materials, previously stored in unlined sand trenches, are now being stored in a dry, monitored and more easily retrievable state in steel containers in MAGS storage buildings. The MAGS project involved design and construction of three elements: a Waste Handling Building, the first of a series of pre-engineered steel storage buildings, and a new Waste Management Area to house the storage buildings and containers of bulk waste. This project was well received by the local municipalities during the public consultation conducted as a part of the licensing process. The MAGS system entered service in 2002 and has operated satisfactorily since then. A second storage building was completed in 2003. (author)

  2. Current status of the waste identification program at AECL's Chalk River Laboratories

    International Nuclear Information System (INIS)

    The management of routine operating waste by Waste Management and Decommissioning (WM and D) at Atomic Energy of Canada Limited's (AECL) Chalk River Laboratories (CRL) is supported by the Waste Identification (WI) Program. The principal purpose of the WI Program is to minimize the cost and the effort associated with waste characterization and waste tracking, which are needed to optimize waste handling, storage and disposal. The major steps in the WI Program are: (1) identify and characterize the processes that generate the routine radioactive wastes accepted by WM and D - radioisotope production, radioisotope use, reactor operation, fuel fabrication, et cetera (2) identify and characterize the routine blocks of waste generated by each process or activity - the initial characterization is based on inference (process knowledge) (3) prepare customized, template data sheets for each routine waste block - templates contain information such as package type, waste material, waste type, solidifying agent, the average non-radiological contaminant inventory, the average radiological contaminant inventory, and the waste class (4) ensure generators 'use the right piece of paper with the right waste' when they transfer waste to WM and D - that is they use the correct template data sheets to transfer routine wastes, by: identifying and marking waste collection points in the generator's facility; ensuring that generators implement effective waste collection/segregation procedures; implementing standard procedures to transfer waste to WM and D; and, auditing waste collection and segregation within a generator's facility (5) determine any additional waste block characterization requirements (is anything needed beyond the original characterization by process knowledge?) This paper describes the WI Program, it provides an example of its implementation, and it summarizes the current status of its implementation for both CRL and non-CRL waste generators. (author)

  3. A compartment model for 90Sr contamination in a wetland at the Chalk River Laboratories

    International Nuclear Information System (INIS)

    Radioactive wastes originating from Canada's nuclear research and development program have been managed at the Atomic Energy of Canada Limited (AECL) Chalk River Laboratories (CRL) since 1946. In 1953 an area called Waste Management Area 'B' (WMA B) was developed to contain low and intermediate level solid waste (LLW and ILW respectively). Initially, all of the wastes were buried in unlined sand trenches or in asphalt lined trenches. These early trenches have been releasing strontium-90 (90Sr) to groundwater since 1954, resulting in an underground contaminant plume. A treatment system was constructed in 1994 and as a result the plume is being intercepted and treated for removal of 90SR. Prior to the establishment of the treatment system the plume extended south and discharged into a watercourse called 'Spring B', then into a wetland area called 'West Swamp'. Routine monitoring of Spring B and the West Swamp outflows for 90Sr has been conducted since the 1960s. A compartment model of the West Swamp was developed and validated against monitoring data for Spring B. The purpose of developing the model was to determine if a standard compartment model could describe 90Sr dynamics in a wetland to support environmental decision making. The model employed mass balance calculations to describe the movement/distribution of 90Sr between the primary system compartments: water/peat, sediment, vegetation and litter. This paper describes how the compartment model was developed and validated. The model can be used as a tool to evaluate remediation alternatives and to provide input to CRL site decommissioning plans. (author)

  4. Management of legacy spent nuclear fuel wastes at the Chalk River Laboratories: the challenges and innovative solutions implemented

    International Nuclear Information System (INIS)

    AECL has operated research reactors at the Chalk River Laboratories (CRL) site since 1947, for the purpose of nuclear energy and scientific research and for the production of radioisotopes. During the 1950s and 60s, a variety of spent nuclear fuel wastes were produced by irradiating metallic uranium and other prototype fuels. These legacy waste fuels were initially stored in water-filled fuel storage bays for a period of several years before being placed in storage containers and transferred to the CRL Waste Management Areas (WMAs), where they have been stored in below-grade, vertical cylindrical steel and concrete structures called 'tile holes'. (author)

  5. Spatial analysis of Carbon-14 dynamics in a wetland ecosystem (Duke Swamp, Chalk River Laboratories, Canada)

    International Nuclear Information System (INIS)

    A detailed survey was conducted to quantify the spatial distribution of 14C in Sphagnum moss and underlying soil collected in Duke Swamp. This wetland environment receives 14C via groundwater pathways from a historic radioactive Waste Management Area (WMA) on Atomic Energy Canada Limited (AECL)'s Chalk River Laboratories (CRL) site. Trends in 14C specific activities were evaluated with distance from the sampling location with the maximum 14C specific activity (DSS-35), which was situated adjacent to the WMA and close to an area of groundwater discharge. Based on a spatial evaluation of the data, an east-to-west 14C gradient was found, due to the influence of the WMA on 14C specific activities in the swamp. In addition, it was possible to identify two groups of sites, each showing significant exponential declines with distance from the groundwater source area. One of the groups showed relatively more elevated 14C specific activities at a given distance from source, likely due to their proximity to the WMA, the location of the sub-surface plume originating from the WMA, the presence of marsh and swamp habitat types, which facilitated 14C transport to the atmosphere, and possibly, 14C air dispersion patterns along the eastern edge of the swamp. The other group, which had lower 14C specific activities at a given distance from the groundwater source area, included locations that were more distant from the WMA and the sub-surface plume, and contained fen habitat, which is known to act as barrier to groundwater flow. The findings suggest that proximity to source, groundwater flow patterns and habitat physical characteristics can play an important role in the dynamics of 14C being carried by discharging groundwater into terrestrial and wetland environments. - Highlights: • Groundwater represents an important source of volatile radionuclides to wetlands. • Habitat type influenced 14C transport from sub-surface to surface environments. • C-14 specific activity

  6. Assessing inventories of past radioactive waste arisings at Chalk River Laboratories

    International Nuclear Information System (INIS)

    Internationally, a great deal of progress has been made in improving the management of currently accumulating and anticipated future radioactive wastes. Progress includes improved waste collection, segregation, characterization and documentation in support of disposal facility licensing and operation. These improvements are not often very helpful for assessing the hazards of wastes collected prior to their implementation, since, internationally, historic radioactive wastes were not managed and documented according to today's methods. This paper provides an overview of Atomic Energy of Canada Limited's (AECL) unique approach to managing its currently accumulating, low-level radioactive wastes at Chalk River Laboratories (CRL) and it describes the novel method AECL-CRL has developed to assess its historic radioactive wastes. Instead of estimating the characteristics of current radioactive wastes on a package-by-package basis, process knowledge is used to infer the average characteristics of most wastes. This approach defers, and potentially avoids, the use of expensive analytical technologies to characterize wastes until a reasonable certainty is gained about their ultimate disposition (Canada does not yet have a licensed radioactive waste disposal facility). Once the ultimate disposition is decided, performance assessments determine if inference characterization is adequate or if additional characterization is required. This process should result in significant cost savings to AECL since expensive, resource-intensive, up-front characterization may not be required for low-impact wastes. In addition, as technological improvements take place, the unit cost of characterization usually declines, making it less expensive to perform any additional characterization for current radioactive wastes. The WIP-III data management system is used at CRL to 'warehouse' the average characteristics of current radioactive wastes. This paper describes how this 'warehouse of information

  7. Ecologically acceptable flows in Chalk rivers

    OpenAIRE

    Acreman, Mike; Dunbar, Michael

    2010-01-01

    The term ‘Chalk rivers’ is used to describe all those water courses dominated by groundwater discharge from Chalk geology. Natural conditions and historical modification have generated an ecosystem, with rich and unique assemblages and with high value to society (e.g. SACs, SSSIs, visual amenity and fisheries. Chalk rivers are considered to be sensitive to hydrological and morphological change and there is concern that flood defence and land drainage schemes, catchment agriculture, urbanisati...

  8. Pre-operational HTO/HT surveys in the vicinity of the Chalk River Laboratories tritium extraction plant

    International Nuclear Information System (INIS)

    Surveys of the concentrations of HT and HTO in the atmosphere downwind of the Chalk River Laboratories reactor facilities were carried out in 1986 November, and in 1989 March, April and September under different conditions of air temperature, wind direction, and snow or vegetative cover. HT usually amounted to 1-5% of total tritium, but values up to 20% were observed, probably resulting from preferential removal of HTO. In all of the surveys, the greater persistence in the atmosphere of HT than of HTO was evident. The existing levels of HT are such that they will not be augmented significantly by chronic releases from the Tritium Extraction Plant (TEP) when it comes into operation. Hence, operation of the TEP will not facilitate studies of the environmental behaviour of chronically released HT. However, longer term studies of the distribution of HT from the existing facilities would be worthwhile. Soil and vegetation HTO levels in the study area are reported. Further studies of the distribution of tritium between the air, soil and vegetation in areas subjected to chronic exposure would be valuable

  9. Management of Legacy Spent Nuclear Fuel Wastes at the Chalk River Laboratories: The Challenges and Innovative Solutions Implemented - 13301

    International Nuclear Information System (INIS)

    AECL's Fuel Packaging and Storage (FPS) Project was initiated in 2004 to retrieve, transfer, and stabilize an identified inventory of degraded research reactor fuel that had been emplaced within in-ground 'Tile Hole' structures in Chalk River Laboratories' Waste Management Area in the 1950's and 60's. Ongoing monitoring of the legacy fuel storage conditions had identified that moisture present in the storage structures had contributed to corrosion of both the fuel and the storage containers. This prompted the initiation of the FPS Project which has as its objective to design, construct, and commission equipment and systems that would allow for the ongoing safe storage of this fuel until a final long-term management, or disposition, pathway was available. The FPS Project provides systems and technologies to retrieve and transfer the fuel from the Waste Management Area to a new facility that will repackage, dry, safely store and monitor the fuel for a period of 50 years. All equipment and the new storage facility are designed and constructed to meet the requirements for Class 1 Nuclear Facilities in Canada. (authors)

  10. US team measurements during the June 1987 experimental HT release at the Chalk River Nuclear Laboratories, Ontario, Canada

    International Nuclear Information System (INIS)

    In June 1987, an experiment was performed at the Chalk River Nuclear Laboratories in Ontario, Canada, to study the oxidation of HT in the environment. The experiment involved a 30-minute release of 100 Ci of HT to the atmosphere at an elevation of one meter. The HTOHT ratios were shown to slowly increase downwind (/approximately/4 /times/ 10/sup /minus/5/ at 50 meters to almost 10/sup /minus/3 at 400 meters) as conversion of HT takes place. For several days after the release, HTO concentrations in the atmosphere remained elevated. Freeze-dried water from vegetation samples was found to be very low in HTO immediately after the release suggesting a very low direct uptake of HTO in air by vegetation. The tritiated water concentration increased during the first day, peaking during the second day (about 400 to 600 pCiml of water at 50 meters from the source) and decreasing by the end of the second day. The organically bound tritium continued to accumulate during the period following exposure (about 10 pCigm dry weight at 50 meters after two days). 4 refs., 6 figs., 2 tabs

  11. Hydrogeochemical processes affecting the migration of radionuclides in a fluvial sand aquifer at the Chalk River Nuclear Laboratories

    International Nuclear Information System (INIS)

    In the mid-1950's two experimental disposals of liquid radioactive waste containing about 700 curries of strontium-90 and cesium-137 were made into pits in sandy ground at one of the disposal areas at Chalk River Nuclear Laboratories. Since then, the wastes have migrated into two nearby aquifers and have chromatographically separated into strontium-90 and cesium-137 plumes moving at velocities less than that of the transporting groundwater. Analysis of radioactively contaminated aquifer sediments showed that most of the strontium-90 is exchangeably adsorbed, primarily to feldspars and layer silicates (mainly biotite); the rest is either specifically adsorbed to iron (III) and perhaps manganese (IV) oxhydroxides or fixed to unknown sinks. Less than one half of adsorbed cesium-137 is exchangeable with 0.5 m calcium chloride; the high levels of cesium-137 adsorption and fixation are probably due to its reaction with micaceous minerals. Complexation of strontium-90 and cesium-137 does not appear to be an important factor affecting their transport or adsorption. In studies of groundwater quality or pollution, dissolved oxygen and sulfide should be measured in addition to the redox potential since it allows independent assessment of the redox levels. The latter were found to affect the mobility of multivalent transition metals and nonmetals. (DN)

  12. Reactor loops at Chalk River

    International Nuclear Information System (INIS)

    This report describes broadly the nine in-reactor loops, and their components, located in and around the NRX and NRU reactors at Chalk River. First an introduction and general description is given of the loops and their function, supplemented with a table outlining some loop specifications and nine simplified flow sheets, one for each individual loop. The report then proceeds to classify each loop into two categories, the 'main loop circuit' and the 'auxiliary circuit', and descriptions are given of each circuit's components in turn. These components, in part, are comprised of the main loop pumps, the test section, loop heaters, loop coolers, delayed-neutron monitors, surge tank, Dowtherm coolers, loop piping. Here again photographs, drawings and tables are included to provide a clearer understanding of the descriptive literature and to include, in tables, some specifications of the more important components in each loop. (author)

  13. Province of Ontario nuclear emergency plan part V - Chalk River

    International Nuclear Information System (INIS)

    The aim of Part 5 of the Provincial Nuclear Emergency Plan is to describe the measures that shall be undertaken to deal with a nuclear emergency caused by the Chalk River Laboratories. This plan deals mainly with actions at the Provincial level and shall by supplemented by the appropriate Municipal Plan. The Townships of Rolph, Buchanan, Wylie, and McKay, the Town of Deep River and the Village of Chalk River are the designated municipalities with respect to CRL. 2 tabs., 5 figs

  14. Advection dispersion modeling of tritium and chloride migration in a shallow sandy aquifer at the Chalk River Laboratories

    International Nuclear Information System (INIS)

    Elevated tritium, helium-3 and chloride concentrations have been measured in groundwaters in a shallow sandy aquifer draining a small lake at the Chalk River Laboratories (CRL), Ontario, Canada. The chloride in the lakewater recharge is 25 times greater than precipitation recharge and forms a continuous, concentrated source of contamination to the aquifer. Tritium (3H) concentrations in both lake and precipitation recharge are elevated owing to the operation of a research reactor on the CRL site and form a continuous spatially distributed source of contamination. The transport of tritium and chloride over the 600 m groundwater flowpath from the lake to the discharge zone are simulated using a 3-D advection-dispersion model. The model requires information on the contaminant input concentrations, the velocity field, dispersion parameters, hydrostratigraphy and boundary conditions. The two independent sets of concentration data provide complementary information to minimize problems associated with the unknown input concentration. The velocity field was estimated from a 3-D simulation of the groundwater flow system; dispersion parameters were estimated from analysis of a controlled natural-gradient tracer test performed previously at the site. The hydrostratigraphy and boundary geometry was characterized by visual logging of borehole sediments, grain size analyses and ground penetrating radar surveys. The abundance of hydrogeologic and geophysical information allowed simulation of the spatial distribution of chloride concentrations with a remarkable degree of accuracy. Simulated and measured peak chloride concentrations differed by less than 15%. The excellent agreement between the simulated and observed chloride concentrations facilitated further modelling of the source and migrational behavior of 3H within this aquifer. We have solved the inverse problem for the 3H source function and successfully modelled the 3H source as a stepwise function. Estimates of

  15. The Turnover Process at Chalk River Laboratories from Operations to Decommissioning

    International Nuclear Information System (INIS)

    Canadian Nuclear Laboratories (CNL) has 200 facilities that account for approximately 2 million square feet of building space. Currently there are 23 facilities undergoing various stages of Decommissioning. An additional 30 facilities are scheduled to be turned over to Decommissioning in 2016. CNL is currently restructuring to transition to a Government Owned/Contractor Operated (GoCo) organization and there will be a focus to accelerate the Decommissioning of legacy facilities on site. In the past, facilities were shutdown and left in various configurations with limited documentation or limited staff knowledge of the status of the facility at the start of Decommissioning. Recently, guidelines have been developed to ensure that any facility being turned over is put into a proper and documented safe shutdown configuration. This paper will look at CNL's process for turnover of facilities from Operations to Decommissioning and identify some of the key Lessons Learned. The turnover of nuclear facilities, administrative and support buildings, components or areas from Operations to Decommissioning needs to be documented and managed to ensure Health, Safety, Security and Environmental (HSSE) risks are identified, eliminated or effectively controlled. At CNL, the turnover document Table of Contents is: Introduction and Purpose; Facility Boundaries; Known Deficiencies; Facility Status; Shutdown Status; Hazards; System/Equipment; Drawings/Maps/Records; Significant Environmental Aspects (SEAs); Interface; and other Transfer Documentation. The transfer documentation specifically covers: - Defined boundaries of the facility, building, component or area at the time of turnover; - Identification of all deficiencies associated with the facility, building, component or area and the person, after turnover, who will be responsible for correcting them; - Confirmation of the status of the facility, building, component or area at the time of turnover with respect to: - The status

  16. The results from the second high-pressure melt ejection test completed in the Molten Fuel Moderator Interaction Facility at Chalk River Laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Nitheanandan, T.; Kyle, G.; O' Connor, R. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2007-09-15

    The Canadian nuclear power generation industry, represented by the CANDU Owners Group (COG), is funding an experimental program at Chalk River Laboratories to study the interaction between the molten material ejected from the fuel channel and the moderator. These experiments are designed to address one of the very low probability postulated accident events considered for CANDU Pressurized Heavy Water Reactors (PHWRs), where an array of fuel channels contain the nuclear fuel and high-temperature, high-pressure coolant. Under severely restricted flow blockage conditions postulated in a fuel channel, the temperature excursion could result in fuel melting, consequential failure of the fuel channel, and ejection of the molten fuel at high pressures into the heavy water moderator at near atmospheric pressure. The objective of the experimental program is to demonstrate that a highly energetic Molten Fuel Moderator Interaction (MFMI) and associated high-pressure pulse can be ruled out. The second high-pressure melt ejection test using 22 kg of prototypical corium was completed recently at Chalk River Laboratories. The second test consisted of heating a thermite mixture of U, U{sub 3}O{sub 8}, Zr, and CrO{sub 3}, simulating the molten material expected in a fuel channel, inside a 1 m length of insulated pressure tube. Once the molten material reached the desired temperature of {approx}2400{sup o}C, the molten material was ejected into the surrounding tank of 63{sup o}C water. At the time of melt ejection, the static pressure in the test section was 3.35 MPa. The confinement vessel pressure reached a peak volume of 201 kPa following the rupture of the test section. The peak dynamic pressure measured on the inner vessel walls ranged between 0.7 MPa and 1 MPa. The dynamic pressure history, debris size, and the effects of the material interacting with tubes representing neighbouring fuel channels were investigated. (author)

  17. The results from the second high-pressure melt ejection test completed in the Molten Fuel Moderator Interaction Facility at Chalk River Laboratories

    International Nuclear Information System (INIS)

    The Canadian nuclear power generation industry, represented by the CANDU Owners Group (COG), is funding an experimental program at Chalk River Laboratories to study the interaction between the molten material ejected from the fuel channel and the moderator. These experiments are designed to address one of the very low probability postulated accident events considered for CANDU Pressurized Heavy Water Reactors (PHWRs), where an array of fuel channels contain the nuclear fuel and high-temperature, high-pressure coolant. Under severely restricted flow blockage conditions postulated in a fuel channel, the temperature excursion could result in fuel melting, consequential failure of the fuel channel, and ejection of the molten fuel at high pressures into the heavy water moderator at near atmospheric pressure. The objective of the experimental program is to demonstrate that a highly energetic Molten Fuel Moderator Interaction (MFMI) and associated high-pressure pulse can be ruled out. The second high-pressure melt ejection test using 22 kg of prototypical corium was completed recently at Chalk River Laboratories. The second test consisted of heating a thermite mixture of U, U3O8, Zr, and CrO3, simulating the molten material expected in a fuel channel, inside a 1 m length of insulated pressure tube. Once the molten material reached the desired temperature of ∼2400oC, the molten material was ejected into the surrounding tank of 63oC water. At the time of melt ejection, the static pressure in the test section was 3.35 MPa. The confinement vessel pressure reached a peak volume of 201 kPa following the rupture of the test section. The peak dynamic pressure measured on the inner vessel walls ranged between 0.7 MPa and 1 MPa. The dynamic pressure history, debris size, and the effects of the material interacting with tubes representing neighbouring fuel channels were investigated. (author)

  18. PCI fuel failure analysis: a report on a cooperative program undertaken by Pacific Northwest Laboratory and Chalk River Nuclear Laboratories

    International Nuclear Information System (INIS)

    Reactor fuel failure data sets in the form of initial power (P/sub i/), final power (P/sub f/), transient increase in power (ΔP), and burnup (Bu) were obtained for pressurized heavy water reactors (PHWRs), boiling water reactors (BWRs), and pressurized water reactors (PWRs). These data sets were evaluated and used as the basis for developing two predictive fuel failure models, a graphical concept called the PCI-OGRAM, and a nonlinear regression based model called PROFIT. The PCI-OGRAM is an extension of the FUELOGRAM developed by AECL. It is based on a critical threshold concept for stress dependent stress corrosion cracking. The PROFIT model, developed at Pacific Northwest Laboratory, is the result of applying standard statistical regression methods to the available PCI fuel failure data and an analysis of the environmental and strain rate dependent stress-strain properties of the Zircaloy cladding

  19. Inverse modeling of Chalk River block

    International Nuclear Information System (INIS)

    Within the framework of the international project HYDROCOIN, a block of fractured monzonitic gneiss within the facilities of Chalk River National Laboratories, Canada, was selected as a test case to study and develop strategies for the calibration and validation of groundwater flow models. Adopting a quasi-three dimensional formulation, the fractures were simulated by two-dimensional finite elements and the rock mass was simulated by strings of line elements. The models were calibrated using, first, steady-state data and, second, transient data. Model calibration involved both identification of model parameters and model structure. Model parameters were obtained by automatic estimation based on measures of the model response and prior information about the model parameters. Excellent agreement between measured and computed heads was obtained for the transient runs. However, such match was only fair in steady-state. Model Structures Identification criteria were used to rank the performance of several model structures. In the steady state the model structure identification criteria did not strongly support increasing the model complexity. However, it is also believed that the information content of the steady state data was quite poor. In contrast, the transient data being both more numerous and more informative than steady-state data, allowed the model structure identification criteria to suggest more complex models. The validation runs were performed on data corresponding to interference pump tests different from the ones used for calibration. The prediction errors in these runs were relatively small and consistent with the calibration uncertainty. Furthermore, the ranking of the models performances during validation runs was the same as the one obtained at the calibration stage, using Model Structure Identification Criteria. (author) 26 figs., 17 tabs., 39 refs

  20. Risk-based Prioritization of Facility Decommissioning and Environmental Restoration Projects in the National Nuclear Legacy Liabilities Program at the Chalk River Laboratory - 13564

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Jerel G.; Kruzic, Michael [WorleyParsons, Mississauga, ON, L4W 4H2 (United States); Castillo, Carlos [WorleyParsons, Las Vegas, NV 89128 (United States); Pavey, Todd [WorleyParsons, Idaho Falls, ID 83402 (United States); Alexan, Tamer [WorleyParsons, Burnaby, BC, V5C 6S7 (United States); Bainbridge, Ian [Atomic Energy Canada Limited, Chalk River Laboratories, Chalk River, ON, K0J1J0 (Canada)

    2013-07-01

    Chalk River Laboratory (CRL), located in Ontario Canada, has a large number of remediation projects currently in the Nuclear Legacy Liabilities Program (NLLP), including hundreds of facility decommissioning projects and over one hundred environmental remediation projects, all to be executed over the next 70 years. Atomic Energy of Canada Limited (AECL) utilized WorleyParsons to prioritize the NLLP projects at the CRL through a risk-based prioritization and ranking process, using the WorleyParsons Sequencing Unit Prioritization and Estimating Risk Model (SUPERmodel). The prioritization project made use of the SUPERmodel which has been previously used for other large-scale site prioritization and sequencing of facilities at nuclear laboratories in the United States. The process included development and vetting of risk parameter matrices as well as confirmation/validation of project risks. Detailed sensitivity studies were also conducted to understand the impacts that risk parameter weighting and scoring had on prioritization. The repeatable prioritization process yielded an objective, risk-based and technically defendable process for prioritization that gained concurrence from all stakeholders, including Natural Resources Canada (NRCan) who is responsible for the oversight of the NLLP. (authors)

  1. Risk-based Prioritization of Facility Decommissioning and Environmental Restoration Projects in the National Nuclear Legacy Liabilities Program at the Chalk River Laboratory - 13564

    International Nuclear Information System (INIS)

    Chalk River Laboratory (CRL), located in Ontario Canada, has a large number of remediation projects currently in the Nuclear Legacy Liabilities Program (NLLP), including hundreds of facility decommissioning projects and over one hundred environmental remediation projects, all to be executed over the next 70 years. Atomic Energy of Canada Limited (AECL) utilized WorleyParsons to prioritize the NLLP projects at the CRL through a risk-based prioritization and ranking process, using the WorleyParsons Sequencing Unit Prioritization and Estimating Risk Model (SUPERmodel). The prioritization project made use of the SUPERmodel which has been previously used for other large-scale site prioritization and sequencing of facilities at nuclear laboratories in the United States. The process included development and vetting of risk parameter matrices as well as confirmation/validation of project risks. Detailed sensitivity studies were also conducted to understand the impacts that risk parameter weighting and scoring had on prioritization. The repeatable prioritization process yielded an objective, risk-based and technically defendable process for prioritization that gained concurrence from all stakeholders, including Natural Resources Canada (NRCan) who is responsible for the oversight of the NLLP. (authors)

  2. Mortality among long-term Chalk River employees

    International Nuclear Information System (INIS)

    Mortality among Chalk River Nuclear Laboratory (CRNL) employees who died during employment or after retirement has been updated to 1985 December 31. Data in tabular form are presented for overall mortality for male and female employees, for the participants in the clean-up for the NRX and NRU reactor accidents and for a group of CRNL staff with lifetime accumulative doses in excess of 0.2 Sv. Data are also presented on the different types of cancer causing death among male employees. No statistically significant increases in cancer deaths were found in any of the groups analyzed. 25 refs

  3. U–Pb, Rb–Sr, and U-series isotope geochemistry of rocks and fracture minerals from the Chalk River Laboratories site, Grenville Province, Ontario, Canada

    International Nuclear Information System (INIS)

    Highlights: • AECL evaluates Chalk River Laboratories site as potential nuclear waste repository. • Isotope-geochemical data for rocks and fracture minerals at CRL site are reported. • Zircons from gneiss and granite yielded U–Pb ages of 1472 ± 14 and 1045 ± 6 Ma. • WR Rb–Sr and Pb–Pb systems do not show substantial large-scale isotopic mobility. • U-series and REE data do not support oxidizing conditions at depth in the past 1 Ma. - Abstract: As part of the Geologic Waste Management Facility feasibility study, Atomic Energy of Canada Ltd. (AECL) is evaluating the suitability of the Chalk River Laboratories (CRL) site in Ontario, situated in crystalline rock of the southwestern Grenville Province, for the possible development of an underground repository for low- and intermediate-level nuclear waste. This paper presents petrographic and trace element analyses, U–Pb zircon dating results, and Rb–Sr, U–Pb and U-series isotopic analyses of gneissic drill core samples from the deep CRG-series characterization boreholes at the CRL site. The main rock types intersected in the boreholes include hornblende–biotite (±pyroxene) gneisses of granitic to granodioritic composition, leucocratic granitic gneisses with sparse mafic minerals, and garnet-bearing gneisses with variable amounts of biotite and/or hornblende. The trace element data for whole-rock samples plot in the fields of within-plate, syn-collision, and volcanic arc-type granites in discrimination diagrams used for the tectonic interpretation of granitic rocks. Zircons separated from biotite gneiss and metagranite samples yielded SHRIMP-RG U–Pb ages of 1472 ± 14 (2σ) and 1045 ± 6 Ma, respectively, in very good agreement with widespread Early Mesoproterozoic plutonic ages and Ottawan orogeny ages in the Central Gneiss Belt. The Rb–Sr, U–Pb, and Pb–Pb whole-rock errorchron apparent ages of most of the CRL gneiss samples are consistent with zircon U–Pb age and do not indicate

  4. Results of detailed ground geophysical surveys for locating and differentiating waste structures in waste management area 'A' at Chalk River Laboratories, Ontario

    International Nuclear Information System (INIS)

    Waste Management Area 'A' (WMA 'A'), located in the outer area of the Chalk River Laboratories (CRL) was in use as a waste burial site from 1946 to 1955. Waste management structures include debris-filled trenches, concrete bunkers and miscellaneous contaminated solid materials, and ditches and pits used for liquid dispersal. In order to update historical records, it was proposed to conduct detailed ground geophysical surveys to define the locations of waste management structures in WMA 'A', assist in planning of the drilling and sampling program to provide ground truth for the geophysics investigation and to predict the nature and locations of unknown/undefined shallow structures. A detailed ground geophysical survey grid was established with a total of 127 grid lines, oriented NNE and spaced one metre apart. The geophysical surveys were carried out during August and September, 1996. The combination of geophysical tools used included the Geonics EM61 metal detector, the GSM-19 magnetometer/gradiometer and a RAMAC high frequency ground penetrating radar system. The geophysical surveys were successful in identifying waste management structures and in characterizing to some extent, the composition of the waste. The geophysical surveys are able to determine the presence of most of the known waste management structures, especially in the western and central portions of the grid which contain the majority of the metallic waste. The eastern portion of the grid has a completely different geophysical character. While historical records show that trenches were dug, they are far less evident in the geophysical record. There is clear evidence for a trench running between lines 30E and 63E at 70 m. There are indications from the radar survey of other trench-like structures in the eastern portion. EM61 data clearly show that there is far less metallic debris in the eastern portion. The geophysical surveys were also successful in identifying previously unknown locations of waste

  5. The results from the second high-pressure melt ejection test completed in the molten fuel moderator interaction facility at Chalk River Laboratories

    International Nuclear Information System (INIS)

    For a Candu reactor and under severely restricted flow blockage conditions postulated in a fuel channel, the temperature excursion could result in fuel melting, consequential failure of the fuel channel, and ejection of the molten fuel at high pressures into the heavy water moderator at near atmospheric pressure. The objective of the experimental program is to demonstrate that a highly energetic Molten Fuel Moderator Interaction (MFMI) and associated high-pressure pulse can be ruled out for a Candu reactor. The second high-pressure melt ejection test using 22 kg of prototypical corium was completed recently at Chalk River Laboratories. The second test consisted in heating a thermite mixture of U, U3O8, Zr, and CrO3, simulating the molten material expected in a fuel channel, inside a 1 m length of insulated pressure tube. Once the molten material reached the desired temperature of about 2400 C degrees, the molten material was ejected into the surrounding tank of 63 C water. At the time of melt ejection, the static pressure in the test section was 3.35 MPa. The confinement vessel pressure reached a peak value of 201 kPa following the rupture of the test section. The peak dynamic pressure measured on the inner vessel walls ranged between 0.7 MPa and 1 MPa. The total debris collected inside the tank was 22.65 kg. The debris inside the inner tank consists of corium, quartz and Zircar. The majority of the corium particles were less than 1 mm in diameter and the calculated value of the mean size of the debris appears to be 0.581 mm. An analysis of the confinement vessel gas inventory indicated 17.6% hydrogen

  6. The results from the second high-pressure melt ejection test completed in the molten fuel moderator interaction facility at Chalk River Laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Nitheanandan, T.; Kyle, G.; O' Connor, R. [Chalk River Laboratories, Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2007-07-01

    For a Candu reactor and under severely restricted flow blockage conditions postulated in a fuel channel, the temperature excursion could result in fuel melting, consequential failure of the fuel channel, and ejection of the molten fuel at high pressures into the heavy water moderator at near atmospheric pressure. The objective of the experimental program is to demonstrate that a highly energetic Molten Fuel Moderator Interaction (MFMI) and associated high-pressure pulse can be ruled out for a Candu reactor. The second high-pressure melt ejection test using 22 kg of prototypical corium was completed recently at Chalk River Laboratories. The second test consisted in heating a thermite mixture of U, U{sub 3}O{sub 8}, Zr, and CrO{sub 3}, simulating the molten material expected in a fuel channel, inside a 1 m length of insulated pressure tube. Once the molten material reached the desired temperature of about 2400 C degrees, the molten material was ejected into the surrounding tank of 63 C water. At the time of melt ejection, the static pressure in the test section was 3.35 MPa. The confinement vessel pressure reached a peak value of 201 kPa following the rupture of the test section. The peak dynamic pressure measured on the inner vessel walls ranged between 0.7 MPa and 1 MPa. The total debris collected inside the tank was 22.65 kg. The debris inside the inner tank consists of corium, quartz and Zircar. The majority of the corium particles were less than 1 mm in diameter and the calculated value of the mean size of the debris appears to be 0.581 mm. An analysis of the confinement vessel gas inventory indicated 17.6% hydrogen.

  7. Report on interlaboratory comparisons of 14C measurements organized by the environmental research branch, Chalk River Laboratories

    International Nuclear Information System (INIS)

    The need for increased quality assurance for measurements performed by the monitoring laboratories at nuclear stations has spurred the introduction of a number of laboratory intercomparisons. This report provides details of two intercomparisons of 14C measurements, including the preparation of potential secondary reference materials, the range of analytical techniques in use at the participating laboratories, and a statistical analysis of the results reported. The agreement evident in the two sets of materials - milk and vegetation - was good. (author)

  8. The Chalk River Tritium Extraction Plant

    International Nuclear Information System (INIS)

    The Chalk River Tritium Extraction Plant for removal of tritium from heavy water is described. Tritium is present in the heavy water from research reactors in the form of DTO at a concentration in the range of 1-35 Ci/kg. It is removed by a combination of catalytic exchange to transfer the tritium from DTO to DT, followed by cryogenic distillation to separate and concentrate the tritium to T2. The tritium product is reacted with titanium and packaged for transportation and storage as titanium tritide. The plant processes heavy water at a rate of 25 kg/h and removes 80% of the tritium and 90% of the protium per pass. Catalytic exchange is carried out in the liquid phase using a proprietary wetproofed catalyst. The plant serves two roles in the Canadian fusion program: it produces pure tritium for use in fusion research and development, and it demonstrates on an industrial scale many of the tritium technologies that are common to the tritium systems in fusion reactors (author)

  9. Dose-effects relationships in wild populations of the aquatic snail Campeloma decisum at Chalk River Laboratories

    International Nuclear Information System (INIS)

    In the last decade regulatory bodies worldwide have implemented standards to protect populations of non-human biota (NHB) from the consequences of radiation exposure. This is a departure from previous regulatory frameworks, which were concerned only with protecting man. The implementation of these new standards initiated an ongoing discussion concerning appropriate dose-rate limits for NHB. For the most part, the data utilized for estimating appropriately protective dose-rate limits has come from data collected via the irradiation of NHB in a laboratory setting. While some dose-effects studies have been performed under field conditions, such experiments represent a minority of the available data. This deficit in the literature has resulted in challenges to the established paradigm, with researchers reporting increased radiosensitivity in NHB under field conditions. However, many such studies overlook critical components of dose-effects analysis: lacking either robust ecological technique or dosimetric rigor. The study cited herein provides rigorous analysis of factors affecting populations of aquatic snails and is intended as a framework for identifying those factors statistically indicative of snail population. These benchmarks (e.g., number of snails, mass of individuals) were employed as proxies for snail population health, and how it was impacted by over two dozen environmental variables. Dose-rates were calculated via a novel voxel model, developed for this study to estimate internal dose rates for the species of interest. A linear regression model was employed to tease out the relationship between individual snails, their environment, and radiation dose rate. There was no evidence that snail population health was influenced by radiation exposure (p=0.70) at the observed dose rates. Of the environmental variables tested, water concentration of Ca was well correlated with snail mass size (p<0.001), while water concentration of P was well correlated with the

  10. Results of detailed ground geophysical surveys for locating and differentiating waste structures in waste management area 'A' at Chalk River Laboratories, Ontario

    Energy Technology Data Exchange (ETDEWEB)

    Tomsons, D.K.; Street, P.J.; Lodha, G.S

    1999-07-01

    Waste Management Area 'A' (WMA 'A'), located in the outer area of the Chalk River Laboratories (CRL) was in use as a waste burial site from 1946 to 1955. Waste management structures include debris-filled trenches, concrete bunkers and miscellaneous contaminated solid materials, and ditches and pits used for liquid dispersal. In order to update historical records, it was proposed to conduct detailed ground geophysical surveys to define the locations of waste management structures in WMA 'A', assist in planning of the drilling and sampling program to provide ground truth for the geophysics investigation and to predict the nature and locations of unknown/undefined shallow structures. A detailed ground geophysical survey grid was established with a total of 127 grid lines, oriented NNE and spaced one metre apart. The geophysical surveys were carried out during August and September, 1996. The combination of geophysical tools used included the Geonics EM61 metal detector, the GSM-19 magnetometer/gradiometer and a RAMAC high frequency ground penetrating radar system. The geophysical surveys were successful in identifying waste management structures and in characterizing to some extent, the composition of the waste. The geophysical surveys are able to determine the presence of most of the known waste management structures, especially in the western and central portions of the grid which contain the majority of the metallic waste. The eastern portion of the grid has a completely different geophysical character. While historical records show that trenches were dug, they are far less evident in the geophysical record. There is clear evidence for a trench running between lines 30E and 63E at 70 m. There are indications from the radar survey of other trench-like structures in the eastern portion. EM61 data clearly show that there is far less metallic debris in the eastern portion. The geophysical surveys were also successful in identifying

  11. Results from the fourth high-pressure melt ejection test completed in the molten fuel moderator interaction facility at Chalk River Laboratories

    International Nuclear Information System (INIS)

    The fourth high-pressure melt ejection test using prototypical corium was completed at Chalk River Laboratories. This test was one of four tests planned by Atomic Energy of Canada Limited to study the potential for energetic interaction between molten fuel and water. The experiments were designed to address one of the very low probability postulated accident events considered for Candu Pressurized Heavy Water Reactors (PHWRs). The accident event considered is the severe reduction in the coolant flow to a single channel. This reduction could result from a blockage in the flow or a break in the inlet piping to a fuel channel. If the reduction in the flow is severe (approaching complete cessation of the flow), the fuel channel will overheat and fail. Such a failure is not predicted to propagate to other fuel channels; the scenario is terminated with the emergency coolant injection. Under severely restricted flow blockage conditions, the temperature excursion could result in fuel melting. Conservative safety analysis assessments consider the implications of the worst-case scenario, which can involve the ejection of the molten material from the fuel channel into the heavy-water moderator. The predictions are that the melt will be finely fragmented and will transfer energy to the moderator as it is dispersed, creating a modest pressure pulse in the calandria vessel. The high-pressure melt ejection experiments funded by the Candu Owners Group have been performed to confirm these predictions and to show that a highly energetic 'steam explosion, ' and associated high-pressure pulse, is not possible. The high-pressure melt ejection test described here consisted of heating 12.5 kg of a thermite mixture U, UO2, Zr, and CrO3, representing the molten material in a fuel channel, inside an insulated pressure tube. When the molten material reached the desired temperature of ∼2400 deg.C, the pressure inside the tube was raised to about 10.5 MP a, and the pressure tube failed due

  12. Initial field measurements on the Chalk River superconducting cyclotron

    International Nuclear Information System (INIS)

    The midplane magnetic field of the Chalk River superconducting cyclotron has been mapped in detail over the full operating range of 2.5 to 5 tesla. The field measuring apparatus is described and results given include measurements of the field stability, reproducibility and harmonic content. (author)

  13. An Investigation into the Transportation of Irradiated Uranium/Aluminum Targets from a Foreign Nuclear Reactor to the Chalk River Laboratories Site in Ontario, Canada - 12249

    International Nuclear Information System (INIS)

    This investigation required the selection of a suitable cask and development of a device to hold and transport irradiated targets from a foreign nuclear reactor to the Chalk River Laboratories in Ontario, Canada. The main challenge was to design and validate a target holder to protect the irradiated HEU-Al target pencils during transit. Each of the targets was estimated to have an initial decay heat of 118 W prior to transit. As the targets have little thermal mass the potential for high temperature damage and possibly melting was high. Thus, the primary design objective was to conceive a target holder to dissipate heat from the targets. Other design requirements included securing the targets during transportation and providing a simple means to load and unload the targets while submerged five metres under water. A unique target holder (patent pending) was designed and manufactured together with special purpose experimental apparatus including a representative cask. Aluminum dummy targets were fabricated to accept cartridge heaters, to simulate decay heat. Thermocouples were used to measure the temperature of the test targets and selected areas within the target holder and test cask. After obtaining test results, calculations were performed to compensate for differences between experimental and real life conditions. Taking compensation into consideration the maximum target temperature reached was 231 deg. C which was below the designated maximum of 250 deg. C. The design of the aluminum target holder also allowed generous clearance to insert and unload the targets. This clearance was designed to close up as the target holder is placed into the cavity of the transport cask. Springs served to retain and restrain the targets from movement during transportation as well as to facilitate conductive heat transfer. The target holder met the design requirements and as such provided data supporting the feasibility of transporting targets over a relatively long period of time

  14. Widespread methanotrophic primary production in lowland chalk rivers

    OpenAIRE

    Shelley, Felicity; Grey, Jonathan; Trimmer, Mark

    2014-01-01

    Methane is oversaturated relative to the atmosphere in many rivers, yet its cycling and fate is poorly understood. While photosynthesis is the dominant source of autotrophic carbon to rivers, chemosynthesis and particularly methane oxidation could provide alternative sources of primary production where the riverbed is heavily shaded or at depth beneath the sediment surface. Here, we highlight geographically widespread methanotrophic carbon fixation within the gravel riverbeds of over 30 chalk...

  15. Widespread methanotrophic primary production in lowland chalk rivers.

    Science.gov (United States)

    Shelley, Felicity; Grey, Jonathan; Trimmer, Mark

    2014-05-22

    Methane is oversaturated relative to the atmosphere in many rivers, yet its cycling and fate is poorly understood. While photosynthesis is the dominant source of autotrophic carbon to rivers, chemosynthesis and particularly methane oxidation could provide alternative sources of primary production where the riverbed is heavily shaded or at depth beneath the sediment surface. Here, we highlight geographically widespread methanotrophic carbon fixation within the gravel riverbeds of over 30 chalk rivers. In 15 of these, the potential for methane oxidation (methanotrophy) was also compared with photosynthesis. In addition, we performed detailed concurrent measurements of photosynthesis and methanotrophy in one large chalk river over a complete annual cycle, where we found methanotrophy to be active to at least 15 cm into the riverbed and to be strongly substrate limited. The seasonal trend in methanotrophic activity reflected that of the riverine methane concentrations, and thus the highest rates were measured in mid-summer. At the sediment surface, photosynthesis was limited by light for most of the year with heavy shading induced by dense beds of aquatic macrophytes. Across 15 rivers, in late summer, we conservatively calculated that net methanotrophy was equivalent to between 1% and 46% of benthic net photosynthetic production within the gravel riverbed, with a median value of 4%. Hence, riverbed chemosynthesis, coupled to the oxidation of methane, is widespread and significant in English chalk rivers. PMID:24695425

  16. The Canadian HT dispersion experiment at Chalk River - June 1987

    International Nuclear Information System (INIS)

    A trace amount (3.54TBq) of tritiated hydrogen, HT, was released to the atmosphere at an experimental field at the Chalk River Laboratories on June 10, 1987 in order to study the environmental behaviour of HT. Experimental results showed that direct oxidation of HT in the atmosphere was small and confirmed that surface soils convert atmospheric HT to HTO. The HTO formed in the soil was slowly emitted to the atmosphere giving rise to the small concentrations of HTO observed in the air during the release and for a period of several weeks thereafter. HTO/HT ratios in air during the plume passage increased with downwind distance from a value of order 10-5 at 5 m to values between 4 x 10-4 and 8 x 10-4 at 400 m. Deposition velocities for HT to soil were in the range 10-4 to 10-3 m s-1. Rates of reemission of tritium from the soil to the atmosphere were typically a few percent per hour within one to two days of the release, declining to less than one percent per hour over two weeks. Tritium deposition velocities and reemission rates determined for soils in the field agreed well with laboratory measurements on field samples, and were similar in range to previous exposure chamber experiments carried out in various countries in the laboratory and field under non-winter conditions. Direct uptake of HT by vegetation was not detected. The time history of vegetation tritium was consistent with uptake of HTO from soil and atmosphere and with incorporation of tritium into the organically bound form through photosynthesis. The experiment provides an extensive data base suitable for the detailed evaluation of mathematical models describing the short range dispersion of tritium. The results indicate that the short range dose from a release of HT would be much less than the dose from an equivalent release of HTO

  17. Use of borehole-geophysical logs and hydrologic tests to characterize crystalline rock for nuclear-waste storage, Whiteshell Nuclear Research Establishment, Manitoba, and Chalk River Nuclear Laboratory, Ontario, Canada

    International Nuclear Information System (INIS)

    A number of borehole methods were used in the investigation of crystalline rocks at Whiteshell Nuclear Research Establishment and Chalk River Nuclear Laboratory in Canada. The selection of a crystalline-rock mass for the storage of nuclear waste likely will require the drilling and testing of a number of deep investigative boreholes in the rock mass. Although coring of at least one hole in each new area is essential, methods for making in-situ geophysical and hydrologic measurements can substitute for widespread coring and result in significant savings in time and money. Borehole-geophysical logging techniques permit the lateral extrapolation of data from a core hole. Log response is related to rock type, alteration, and the location and character of fractures. The geophysical logs that particularly are useful for these purposes are the acoustic televiewer and acoustic waveform, neutron and gamma, resistivity, temperature, and caliper. The acoustic-televiewer log of the borehole wall can provide high resolution data on the orientation and apparent width of fractures. In situ hydraulic tests of single fractures or fracture zones isolated by packers provide quantitative information on permeability, extent, and interconnection. The computer analysis of digitized acoustic waveforms has identified a part of the waveform that has amplitude variations related to permeabilities measured in the boreholes by packer tests. 38 refs., 37 figs., 4 tabs

  18. Field burial results and SIMS analysis of the Chalk River glass blocks

    International Nuclear Information System (INIS)

    In 1959, 25 2-kg hemispherical blocks of aluminosilicate glass, each containing ∼90 MBq/g of mixed fission products, were buried in a sandy soil aquifer in the waste management area at the Chalk River Nuclear Laboratories. A second set of blocks, containing ∼260 MBq/g mixed fission products, was buried in 1960. One block from each test was retrieved in 1978 to undergo chemical and surface analysis. This report reviews the migration of the 90Sr and 137Cs plume in the soil and presents the results of SIMS depth profiling of the surface of a glass block. (author)

  19. Field burial results and SIMS analysis of the Chalk River glass blocks

    International Nuclear Information System (INIS)

    In 1959, 25 2-kg hemispherical blocks of aluminosilicate glass, each containing ∼90 MBq/g of mixed fission products, were buried in a sandy soil aquifer in the waste management area at the Chalk River Nuclear Laboratories. A second set of blocks, containing ∼260 MBq/g mixed fission products, was buried in 1960. One block from each test was retrieved in 1978 to undergo chemical and surface analysis. This report reviews the migration of the /sup 90/Sr and /sup 137/Cs plume in the soil and presents the results of SIMS depth profiling of the surface of a glass block

  20. The role of alluvial valley deposits in groundwater–surface water exchange in a Chalk river

    OpenAIRE

    Abesser, Corinna; Shand, Paul; Gooddy, Daren; Peach, Denis

    2008-01-01

    To understand the processes of surface water–groundwater exchange in Chalk catchments, a detailed hydrogeochemical study was carried out in the Lambourn catchment in southeast England. Monthly monitoring of river flow and groundwater levels and water chemistry has highlighted a large degree of heterogeneity at the river-corridor scale. The data suggest an irregular connection between the river, the alluvial deposits, and the Chalk aquifer at the study site. The groundwaters in the alluvial gr...

  1. Performance of the Chalk River 36Cl AMS system

    International Nuclear Information System (INIS)

    The MP Tandem Injector of the Chalk River TASCC (Tandem Accelerator Superconducting Cyclotron) Facility is being used for 36Cl determinations in studies relating to hydrology and low and high level nuclear waste management. In addition to the accelerator, the computer controlled system comprises a multiple-sample, medium-current ion source, a high resolution injector, a low resolution velocity filter, a gas filled magnet and a Bragg-type particle detection/identification system. Accuracies of 5--10% have been achieved with good suppression of 36S and background levels as low as 5x10-1536Cl/Cl. Following a brief overview of the system, detailed results are presented for the performance of the gas-filled magnet and particle detector as well as for sources of background including ion source memory effects

  2. Experience at Chalk River with a cw electron accelerator

    International Nuclear Information System (INIS)

    For several years a group at Chalk River has been studying the behaviour of structures operated in the cw mode under heavy beam loading. Three side-coupled structures, modelled on the LAMPF design, have been built and tests up to 50% beam loading have been performed on two of them. Control systems have been developed to regulate the disturbances arising from high average power in a multi-tank accelerator and procedures worked out to handle beam currents up to 20 mA at 4 MeV. A pancake-coupled structure has been designed for high power operation and results of low power tests on an aluminum model are presented. Tests at high power with a 50 mA electron beam are planned. (author)

  3. Proceedings of a workshop on geophysical and related geoscientific research at Chalk River, Ontario

    International Nuclear Information System (INIS)

    A large part of the Canadian Nuclear Fuel Waste Management Program is geoscience research and development aimed at obtaining information to quantify the transport of radionuclides through the geosphere and at determining the geotechnical properties required for disposal vault design. The geosphere at potential disposal sites is characterized in part by the use of remote sensing (geophysical) methods. In 1977 public concern about the disposal of radioactive waste resulted in field work being restricted to the site of Chalk River Nuclear Laboratories, which was used to develop, evaluate and compare various techniques in order to optimize the methods for obtaining geoscience information. Methods tested at Chalk River are to be applied at other research sites. Most investigations have been carried out around Maskinonge Lake, using about thirty boreholes sink into bedrock. The boreholes provide subsurface geological information that can be used as a reference to compare the responses of various geophysical methods and equipment. Regional studies, including airborne geophysical surveys, have also been conducted. The 25 papers presented at this workshop provide comprehensive documentation of the most significant results of geophysical studies. The workshop also provided an evaluation of geophysical techniques and their utility to the Nuclear Fuel Waste Management Program

  4. ACE - an algebraic compiler and encoder for the Chalk River datatron computer

    International Nuclear Information System (INIS)

    ACE is a program written for the Chalk River Datatron (Burroughs 205) Computer to enable the machine to compile a program for solving a problem from instructions supplied by the user in a notation related much more closely to algebra than to the machine's own code. (author)

  5. WIMS-CRNL: A user's manual for the Chalk River version of WIMS

    International Nuclear Information System (INIS)

    This report describes the preparation of the input for WIMS-CRNL, the Chalk River version of the WIMS lattice code. Also included are notes on the operation of the code, contents of the associated libraries, and the relation of WIMS-CRNL to other versions of the code

  6. Canadian fusion breeder blanket program: Irradiation facilities at chalk river*1

    Science.gov (United States)

    Hastings, I. J.; Burton, D. G.; Celli, A.; Delaney, R. D.; Fehrenbach, P. J.; Howe, L. M.; Larson, L. L.; MacEwen, S. R.; Miller, J. M.; Naeem, T. A.; Sawicki, J. A.; Swanson, M. L.; Verrall, R. A.; Zee, R. H.

    1986-11-01

    The major irradiation facility at Chalk River Nuclear Laboratories (CRNL) is the NRU research reactor. Both unvented and vented capsule experiments on candidate blanket ceramics can be performed. In the unvented tests, tritium release data (HT-to-HTO ratio, tritium retention) are obtained by post-irradiation heating of the breeder ceramic in the presence of a sweep gas. Four tests have been completed on Li 2O and LiAlO 2. Effects of sweep gas composition, extraction vessel material and ceramic properties have been determined. Two unvented irradiations under the BEATRIX international breeder exchange program have been completed; analysis is underway. The vented tests involve long-term irradiation of candidate blanket materials. CRITIC-I, scheduled for mid-1986 under BEATRIX, will examine ANL-fabricated Li 2O in a six-month irradiation at 700-1200 K, varying sweep gas composition, with on-line HT/HTO measurement. Additionally, accelerator simulation techniques are available, using 70 kV and 2.0 MV mass separators, a 2.5 MV Van de Graaff accelerator and a tandem accelerator super-conducting cyclotron, the latter allowing irradiation with protons, deuterons or helium at 18-20 MeV.

  7. Response of invertebrates from the hyporheic zone of chalk rivers to eutrophication and land use.

    Science.gov (United States)

    Pacioglu, Octavian; Moldovan, Oana Teodora

    2016-03-01

    Whereas the response of lotic benthic macroinvertebrates to different environmental stressors is a widespread practice nowadays in assessing the water and habitat quality, the use of hyporheic zone invertebrates is still in its infancy. In this study, classification and regression trees analysis were employed in order to assess the ecological requirements and the potential as bioindicators for the hyporheic zone invertebrates inhabiting four lowland chalk rivers (south England) with contrasting eutrophication levels (based on surface nitrate concentrations) and magnitude of land use (based on percentage of fine sediments load and median interstitial space). Samples of fauna, water and sediment were sampled twice, during low (summer) and high (winter) groundwater level, at depths of 20 and 35 cm. Certain groups of invertebrates (Glossosomatidae and Psychomyiidae caddisflies, and riffle beetles) proved to be good indicators of rural catchments, moderately eutrophic and with high fine sediment load. A diverse community dominated by microcrustaceans (copepods and ostracods) were found as good indicators of highly eutrophic urban streams, with moderate-high fine sediment load. However, the use of other taxonomic groups (e.g. chironomids, oligochaetes, nematodes, water mites and the amphipod Gammarus pulex), very widespread in the hyporheic zone of all sampled rivers, is of limited use because of their high tolerance to the analysed stressors. We recommend the use of certain taxonomic groups (comprising both meiofauna and macroinvertebrates) dwelling in the chalk hyporheic zone as indicators of eutrophication and colmation and, along with routine benthic sampling protocols, for a more comprehensive water and habitat quality assessment of chalk rivers. PMID:26531711

  8. Facilities for Waste Management at Chalk River, Canada

    International Nuclear Information System (INIS)

    The waste disposal areas used by the Atomic Energy of Canada Limited are situated in a rock basin filled with glacial till and sand, draining into the Ottawa River. Low-activity liquid effluent is run into pits in the sand, which are filled with small rocks to prevent contact of liquid with the air. Medium- level liquid is mixed with cement in drums which are stacked and totally enclosed in concrete trenches; medium-level solids are buried in concrete-lined trenches; high-level solids are placed in holes lined with steel or concrete piping. Special facilities are provided for organic liquids and bottled wastes. Details will be given of the structural work and procedures, with an outline of the results of environmental monitoring. (author)

  9. Simulations of Two-Well Tracer Tests in Stratified Aquifers at the Chalk River and the Mobile Sites

    Science.gov (United States)

    Huyakorn, Peter S.; Andersen, Peter F.; Molz, Fred J.; Güven, Oktay; Melville, Joel G.

    1986-07-01

    A simulation study of two-well injection-withdrawal tracer tests in stratified granular aquifers at two widely separated sites is presented. The first site is located near the Chalk River Nuclear Laboratories in Canada, and the second site is located in Mobile, Alabama. Field data and test conditions at these sites are substantially different in terms of vertical distributions of hydraulic conductivity, well spacings, flow rates, test durations, and tracer travel distances. Furthermore, the test at the Chalk River site was conducted in a recirculating mode, whereas the test at the Mobile site was conducted in a nonrecirculating mode. Simulations of these tests were performed in three dimensions using the curvilinear finite element model developed in the previous paper of this series. The simulations incorporated measured vertical variations in relative hydraulic conductivity and local dispersivity values that are small fractions (between 1/1000 and 1/100) of the spacing between the injection and the withdrawal wells. The local dispersivities are used to account for local hydrodynamic dispersion and are chosen independently so that they are not affected by the scales of the tests. Simulation results obtained from the model are presented. Interpretation of these results is made in conjunction with measured breakthrough curves at the withdrawal well and multilevel observation wells. For the Chalk River site, predicted and measured breakthrough curves at the withdrawal well are in good agreement over the earlier part of the test duration. Deviation of the field data from the model prediction occurs over the second part, where the predicted breakthrough curves show a declining trend but the field data plot does not. For the Mobile site, predicted and measured breakthrough curves at the withdrawal well show similar trends throughout the entire test duration and are in good agreement overall. Model predictions of the effect of hydraulic conductivity stratification on

  10. Laboratory measurements of the electrokinetic and electrochemical potential in chalk, with application to monitoring of saline intrusion in the UK chalk aquifer

    Science.gov (United States)

    MacAllister, D.; Jackson, M.; Butler, A. P.; Vinogradov, J.

    2012-12-01

    . Groundwater was placed in a reservoir on one side of the chalk sample and seawater was placed in a second reservoir on the other side of the sample. Two experiments were conducted, one with the sample saturated initially with groundwater and the second with the sample saturated initially with seawater. The resulting EC potential across the sample, after accounting for electrode effects, were found to be -60 mV and -70 mV respectively, and were strongly influenced by charge exclusion from the pore-space. Our results suggest that electrochemical potentials across a saline front in the UK chalk aquifer may be large and are expected to dominate the measured SP during pumped and ambient conditions. Future work will focus on accounting for the presence of fractures, and on using the insight gained from the laboratory results to design a method to detect saline intrusion in field experiments.

  11. Magnetic field related mechanical tolerances for the proposed Chalk River superconducting heavy-ion cyclotron

    International Nuclear Information System (INIS)

    A four sector azimuthally varying field cyclotron with superconducting main coils has been proposed as a heavy-ion post-accelerator for the Chalk River MP Tandem van de Graaff. The radial profile of the average axial field will be variable using movable steel trim rods. The field errors due to coil, trim rod and flutter pole imperfections are calculated. Those considered are errors in the axial field, first and second azimuthal harmonic axial fields, transverse field and first azimuthal harmonic transverse field. Such fields induce phase slip, axial or radial coherent oscillations and can result in axial or radial beam instability. The allowed imperfections (tolerances) required to retain stability and maintain acceptably small coherent oscillation amplitudes are calculated. (author)

  12. Using environmental tracers to assess the extent of river-groundwater interaction in a quarried area of the English Chalk

    Energy Technology Data Exchange (ETDEWEB)

    Darling, W.G., E-mail: wgd@bgs.ac.uk [British Geological Survey, Maclean Building, Wallingford OX10 8BB (United Kingdom); Gooddy, D.C. [British Geological Survey, Maclean Building, Wallingford OX10 8BB (United Kingdom); Riches, J. [Thames Water Utilities Limited, Rose Kiln Court, Rose Kiln Lane, Reading RG2 0BY (United Kingdom); Wallis, I. [British Geological Survey, Maclean Building, Wallingford OX10 8BB (United Kingdom)

    2010-07-15

    The Swanscombe area of Kent, SE England represents a typical example of a heavily quarried Chalk area currently undergoing re-development. Because the Chalk is also an important aquifer, a good understanding of groundwater movement is required if environmental impacts are to be minimised and the water resource maximised. In particular, the nature of the relationship between the River Darent and groundwater in the Swanscombe Chalk Block requires better characterisation. Here, 'environmental tracers' in the form of ambient concentrations of stable isotopes, chlorofluorocarbons (CFCs), sulphur hexafluoride (SF{sub 6}) and tritium ({sup 3}H) are used to investigate this and other aspects of groundwater movement in the vicinity of the quarries. Stable isotopic contrasts indicate little evidence for widespread river infiltration to the regional Chalk aquifer, although stable isotope and {sup 3}H data suggest that 20-35% of the abstraction by river-valley public water supply boreholes may be derived from the river. The CFCs, while present at above-modern concentrations in almost all groundwaters, can be used as tracers, indicating basically S-N flowpaths in the area south of the quarries, though sub-karstic conduits associated with areas of Palaeogene cover add a level of uncertainty at the local scale. Simple piston flow residence times based on SF{sub 6} range from 1 to 17 a, but the data are probably better interpreted in terms of mixing between varying amounts of modern recharge derived from the south and deeper stored groundwater. The information gained from environmental tracers can therefore contribute to effective resource management.

  13. Lithology, fracture intensity, and fracture filling of drill core from Chalk River research area, Ontario

    International Nuclear Information System (INIS)

    In 1977, 1978, and 1979, nine inclined cored boreholes, ranging in length from 113 to 704 m, were drilled in the Chalk River Research Area in order to define the geological subsurface characteristics of the rock mass at several selected test areas. A total of 2,458 metres of NQ-3 and HQ-3 core was obtained from the nine boreholes. Orthogneiss was the most predominant rock type intersected by the boreholes. Pyroxenite, amphibolite, metagabbro and dykes of diabase, pegmatite and aplite were also encountered. The crosscutting relationships and textures within the rocks indicate that the relative ages of the rock units, from youngest to oldest, are diabase; aplite and pegmatite dykes with no defined fabric; pyroxenite; meta-ferrogabbro; amphibolite; aplite and pegmatite dykes and pegmatite pods with a defined fabric; and orthogneiss. Textural characteristics and mineral assemblages indicate that the orthogneisses in the Chalk River Area are a product of regional, medium to high-grade metamorphism and belong to the upper amphibilite to granulite facies. A total of 35,597 fractures (an average of 14.5 fractures per metre) was observed in the core. Brecciated zones and open fractures were noted in the core from all of the boreholes, and major faults were identified in four of the nine boreholes. Nearly all of the fractures have a thickness between 0.4 and 1.2 mm and contain one or more types of filling. Chlorite and calcite are the most common types of filling. Epidote, hematite, clays, sulphides, talc, sericite, and rock fragments also occur in the fractures. The crosscutting relationships between fractures and the sequence of filling layers within the fractures indicate that several episodes of fracturing have occurred and that fractures containing more than one filling have probably been reactivated. A comparison of the geological logs from one of the boreholes with natural gamma, neutron-neutron and magnetic susceptibility logs indicates that certain rock types and

  14. The reduction of sample memory effects in the Chalk River AMS ion source

    International Nuclear Information System (INIS)

    The mechanism underlying Cl and I sample-to-sample interference in the new Chalk River AMS ion source has been studied and compared with the interference observed in an earlier ion source of different internal geometry. The distribution of sputtered material and its degree of migration was measured with the radioactive tracer, 82Br. The temperature dependence of the surface constituents was measured with the elastic recoil detection (ERD) technique and the effect of sample geometry and ion source cleaning was studied with elevated (5 x 10-10) 36Cl/Cl and 129I/I samples. These measurements indicate that a hot (> 350oC) aperture plate ahead of the sample can prevent the sputtering of contaminated regions near the sample. The plate itself remains relatively free of Cl or I itself since these elements or their Cs-gettered compounds are desorbed at this temperature. A small, fixed quantity of Cl or I on this surface is observed, which if sputtered by Cs+ ions, may contribute to ion source memory. Relative sample-to-sample interference for both Cl and I is about 10-3 after 20 min or l0-4 after 60 min. (author)

  15. Simulating Heterogeneous Infiltration and Contaminant leaching Processes at Chalk River, Ontario

    Science.gov (United States)

    Ali, M. A.; Ireson, A. M.; Keim, D.

    2015-12-01

    A study is conducted at a waste management area in Chalk River, Ontario to characterize flow and contaminant transport with the aim of contributing to improved hydrogeological risk assessment in the context of waste management. Field monitoring has been performed to gain insights into the unsaturated zone characteristics, moisture dynamics, and contaminant transport rates. The objective is to provide quantitative estimates of surface fluxes (quantification of infiltration and evaporation) and investigations of unsaturated zone processes controlling water infiltration and spatial variability in head distributions and flow rates. One particular issue is to examine the effectiveness of the clayey soil cap installed to prevent infiltration of water into the waste repository and the top sand soil cover above the clayey layer to divert the infiltrated water laterally. The spatial variability in the unsaturated zone properties and associated effects on water flow and contaminant transport observed at the site, have led to a concerted effort to develop improved model of flow and transport based on stochastic concepts. Results obtained through the unsaturated zone model investigations are combined with the hydrogeological and geochemical components and develop predictive tools to assess the long term fate of the contaminants at the waste management site.

  16. The Chalk River Nuclear Laboratories contingency plan -a brief description

    International Nuclear Information System (INIS)

    A brief description of the contingency plan which deals with both the on-site and off-site consequences of a serious nuclear accident is given. The off-site consequences of different size releases and the subsequent action taken by employees, radiation protection experts, municipal, Provincial and Federal authorities is described and the interaction of the various groups is discussed. (author)

  17. Nuclear safety review process at Chalk River Nuclear Laboratories

    International Nuclear Information System (INIS)

    Atomic Energy of Canada has a extensive health and safety organization in place to protect its facilities and employees, and the public in general. This consists of the operating groups who have the primary responsibility for safety, and a network of safety advisory groups and safety review committees for providing the broadest possible overview of facility safety. A rigorous multi-stage nuclear safety review process is specified by Company policies and procedures to ensure that all activities have undergone thorough review and have satisfied predetermined requirements. For major facilities, this includes up to five distinct safety review and licensing stages with approvals being required from both the Atomic Energy Control Board and AECL Nuclear Safety Advisory Committee for the major steps in the process. In addition, each approved operating facility, including its experimental program, undergoes regular independent safety review and assessment of ongoing operation. The role of the AECL Safety and Reliability Directorate in these activities is described. Other aspects of the overall safety review process including the development of safety criteria, the development of standard safety documentation, and the application of quality assurance to safety assessment activities are discussed. Some thinking is presented on possible future directions in the continuing evolution of these overall safety processes

  18. Magnetic susceptibility of rocks from boreholes CR-1 to CR-9 at Chalk River

    International Nuclear Information System (INIS)

    Magnetic susceptibility measurements made on rock cores obtained from boreholes at the Chalk River Research Area indicate that the foliated, granitic to granodioritic gneisses are weakly magnetic. Susceptibility values are about 5 x 10-4 S.I., two orders of magnitude less than average values for the Atikokan or Lac du Bonnet granites. Interpretation of the variations recorded in the gneisses in all cores is difficult because the average magnetic susceptibility level is near the limit of resolution of the measuring instrument used. However, in CR-6 and CR-9, mafic units intersect the boreholes and high magnetic susceptibility zones are seen. In CR-9 susceptibility values of the order of 5 x 10-2 S.I. characterize a dyke at depths of 40 to 60 m. A second high-susceptibility zone, distinctly different from the shallower one, is recorded at depths of 580 to 670 m with susceptibility of the orders of 5 x 10-3 S.I. This difference in susceptibility suggests mineralogical differences between the two units. The distinctive susceptibility signatures of these two units are better differentiated than signatures obtained from the other geophysical logs. In CR-6 only one high-susceptibility zone (of the order of 5 x 10-2 S.I.) is recorded in CR-6, at depths of 200 to 290 m. Its signature is similar in shape and intensity to the shallower unit observed in CR-9. Preliminary interpretation suggest continuity between these two zones. In CR-2 and CR-5, significant correlations exist among magnetic susceptibility, temperature anomalies and fracture occurrences. Contrary to observations at other research areas, fracture signatures in these two holes correspond to slight increases in susceptibility values. Alteration products associated with the fractures have higher susceptibility than the gneisses. Even though most of the recorded variations of the magnetic susceptibility are near the detection limit of the measuring instrument, significant features were observed and are discussed in

  19. Mortality study of Canadian military personnel exposed to radiation: atomic test blasts and Chalk River nuclear reactor clean-ups, 1950's

    International Nuclear Information System (INIS)

    This report describes a historical cohort study of the group of Canadian military personnel exposed to radiation in the 1950s at atomic bomb test blasts in the U.S. and Australia, and at clean-up operations at the Chalk River Nuclear Laboratories. Overall and cause-specific mortality in the exposed group was compared to that of the control cohort of unexposed military personnel, matched on age, service, rank and trade. Analyses indicated no elevation in the exposed cohort, in overall or cause-specific mortality due to diseases associated with radiation. Since this study was restricted to an investigation of mortality, we must stress that we cannot generalize these results or conclusions to current morbidity experienced by the exposed cohort

  20. Canada, Atomic Energy of Canada Limited (AECL), Chalk River Labs: Reuse and Licence Termination of a Number of Facilities at the Chalk River Labs to Allow for Refurbishment of the Site. Annex A. I-1

    International Nuclear Information System (INIS)

    Chalk River Labs is located along the Ottawa River in Ontario, Canada, approximately 200 km north-west of Ottawa. The site began construction in 1944 following the expropriation of approximately 1 500 ha of land. A number of research reactors were constructed at the site along with numerous nuclear labs, hot cells and administrative facilities in support of the research and development work planned for the site. The principal occupants of the Chalk River site are AECL employees with a strong presence from National Resources Canada (NRC) and other small research groups. The site is undergoing substantial changes with an emphasis on minimizing the impact of increasing the builtup area footprint in conjunction with site upgrades and new build projects. To accomplish this task, a number of refurbishment and decommissioning projects were planned. Decommissioning projects were initiated to make room for new development through a number of initiatives. The decommissioning mandate includes the removal of a select group of original deteriorating facilities to make room for new construction and to decommission other facilities to facilitate redevelopment and reuse of the available space. In Canada, the Canadian Nuclear Safety Commission (CNSC) issues nuclear licences. The licensees must demonstrate that it is safe to continue operations of the nuclear site and request a renewal of their licence. CNSC will issue a new operating licence for a specific period of time at which the licensee must demonstrate that it is safe to proceed with a licence renewal. A request to terminate a licensable activity must be submitted to the CNSC. Upon approval to proceed, it must be demonstrated that the licensable activities have ceased and the facility has been appropriately decommissioned. Licence termination requires a demonstration that the land or previous activities presents a low risk and that the process can be used to support redevelopment because it results in a scrutinized

  1. Laboratory and field measurements of the self-potential (SP) in chalk, with application to monitoring of saline intrusion

    Science.gov (United States)

    MacAllister, D.; Jackson, M.; Butler, A. P.; Vinogradov, J.

    2013-12-01

    Saline intrusion is a global phenomenon, affecting the availability of freshwater in coastal aquifers. The aim of this work is to investigate whether measurements of self-potential (SP) can be used to monitor the intrusion of seawater into coastal aquifers, with specific application to the UK chalk aquifer in the vicinity of Brighton on the south coast of the UK. The SP arises to maintain electrical neutrality when a separation of charge occurs due to gradients in pressure (electrokinetic (EK) or streaming potential) and concentration (electrochemical (EC) potential). Concentration gradients are a characteristic feature of saline intrusion and may give rise to a measureable EC potential. In addition, an EK potential will arise during abstraction. Laboratory and field SP measurements are used to investigate the magnitude of the EK and EC potentials in the UK chalk aquifer during saline intrusion. Laboratory measurements yield an EK coupling coefficient, relating the gradient in voltage to the gradient in pressure when the total current is zero, of -60 mV/MPa in samples saturated with groundwater, and -1 mV/MPa in samples saturated with seawater. This result agrees with earlier work suggesting the EK potential is suppressed at high salinity due to a compressed electrical double layer. The EC coupling is dominated by diffusion potentials arising from the concentration gradient across the saline front. Field experiments suggest that the EK component of the SP in the chalk is very small under ambient conditions, even in freshwater zones, because gradients in hydraulic head are small owing to the high conductivity of the pervasive fracture networks. However, a pumping test conducted in the chalk aquifer at a field site in Berkshire induced a measureable EK response with a coupling coefficient of magnitude consistent with the freshwater EK coupling coefficient obtained in the laboratory. SP monitoring at an observation borehole near Brighton reveals semi-diurnal SP

  2. Low-level radioactive river sediment particles originating from the Chalk river nuclear site carry a mixture of radionuclides and metals

    Energy Technology Data Exchange (ETDEWEB)

    Lind, Ole Christian; Cagno, Simone; Salbu, Brit [Norwegian University of Life Sciences - NMBU, Center of Excellence in Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Aas (Norway); Falkenberg, Gerald [Photon science, DESY, Hamburg (Germany); Janssens, Koen; Nuyts, Gert; Vanmeert, Frederik [AXIL, Department of Chemistry, University of Antwerpen (Belgium); Jaroszewicz, Jakub [Faculty of Materials Science and Engineering, Warsaw University of Technology, Warsaw (Poland); Priest, Nicholas D.; Audet, Marc [Nuclear Science Division, AECL Chalk River Laboratories (Canada)

    2014-07-01

    The Chalk River Laboratory of Atomic Energy of Canada Ltd., site is located on the Ottawa River approximately 200 km northwest of Ottawa, Canada. The site has two large research reactors: NRX, which operated from 1947 to 1991 and NRU, which continues to operate and is used to produce a significant fraction of the world's supply of medical isotopes. During the course of the operation of the NRX reactor small quantities of radioactive particles were discharged to the Ottawa River through a process sewer discharge pipe. These are now located in river bed sediments within a 0.08 km² area close to the discharge pipe. In the present study, selected particles were isolated from riverbed sediments. These were then characterized by environmental scanning electron microscopy with energy dispersive micro X-ray analysis (ESEM-EDX). This was undertaken to obtain information on particle size, structure and the distribution of elements across particle surfaces. Based on the results of ESEM-EDX, particles were selected for X-ray absorption nano-tomography analysis, which provides videos showing the 3D density distribution of the particles. Furthermore, 2D and 3D Synchrotron Radiation based X-ray techniques (micro-X-ray fluorescence; micro-XRF, micro-X-ray absorption near edge spectroscopy; micro-XANES and micro-X-ray diffraction; micro-XRD) with submicron resolution (beam size 0.5 μm) were employed to investigate the elemental and phase composition (micro-XRF/XRD) and oxidation states (micro-XANES) of matrix elements with high spatial resolution and sensitivity. Results show that the particles investigated so far varied according to: 1) <~40 μm diameter sized U fuel particles similar in structure to particles observed from Chernobyl and Krasnoyarsk-26 and 2) larger particles with diameters up to several hundred μm. The larger particles comprised a matrix of low density, sediment material with high density inclusions that contained a range of metals including Cu, Cr, As

  3. Borehole television surveys and acoustic televiewer logging at the National Hydrology Research Institute's hydrogeological research area in Chalk River, Ontario

    International Nuclear Information System (INIS)

    This paper presents the results of studies of the fracture distribution and fracture orientation encountered in 23 boreholes at the National Hydrology Research Institute's Hydrogeological Research Area in Chalk River. Borehole television camera and acoustic televiewer data were used to determine: the fracture distribution as a function of depth; the aperture distribution as a function of depth; and, the predominant fracture sets. Fracture frameworks of the rock mass were constructed based on these data. The rock mass was found to be moderately to well fractured. Many open fractures were detected in the CR-series boreholes, especially in the upper 70 m. Three interconnecting, highly fractured zones are intersected by the CR-series boreholes between elevations of 96.80 m and 56.56 m, 34.91 m and -22.42 m, and -56.56 m and -61.31 m, while two interconnecting fracture zones are encountered by the FS-series boreholes between elevations 103.89 m and 96.64 m, and 108.20 m and 95.08 m. The predominant fracture sets strike east-west, northwest and indeterminably subhorizontal. The predominant set of veins strikes to the south. The subsurface fracture patterns and vein patterns were found to be similar to those observed on surface outcrops

  4. Evaluation of five surface EM techniques for fracture detection and mapping at the Chalk River research area, Ontario

    International Nuclear Information System (INIS)

    Experimental field surveys were carried out with five surface electromagnetic (EM) systems at the Chalk River research area in 1980 and 1981. The purpose of the surveys was to test the usefulness of some new and a few existing EM systems for mapping fracture and shear zones in the highly resistive monzonite gneiss in the survey area. Fractures in the gneiss are often filled with water rich in ions, making the fractures medium to poor-grade conductors. The detection of these fractures by surface electromagnetic surveys depends on their conductance values (product of conductivity (s) and thickness (t)), the conductivity of the host rock, depth of the conductors, and strength, orientation, and frequency of the exciting field. The five EM systems used in the test surveys were: the local loop VLF-EM system; Max-Min II horizontal loop EM system; geonics EM-34 ground-mapping system; geonics EM-37; and, Maxi-Probe systems. Analysis of the field results shows that: the local loop VLF transmitter is a suitable substitute for Navy VLF stations; VLF and Max-Min II systems can detect poor conductors coincident with geologically defined lineaments and fracture zones, however, it is difficult at the moment to distinguish between near-vertical conductors in the bedrock and conductive overburden filling depressions in the bedrock surface; geonics EM-34 is not suitable in highly resistive terrain or in the presence of near-vertical conductors; and, the geonics EM-37 and Maxi-Probe systems detected possible subhorizontal conductors at depths of over 200 m. The presence of these could not be verified because of the lack of borehole control in those areas. An evaluation of the five systems indicates that VLF-EM and Max-Min II systems are most useful for detection of vertical and near-vertical fracture zones in the top 100 m, while EM-37 and Maxi-Probe systems are useful for detecting fracture zones at greater depths

  5. Savannah River Laboratory monthly report, October 1991

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, J.M. [comp.

    1991-12-31

    This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation, tritium facilities and production; separations operations; environmental concerns; and waste management. (FI)

  6. Savannah River Laboratory monthly report, October 1991

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, J.M. (comp.)

    1991-01-01

    This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation, tritium facilities and production; separations operations; environmental concerns; and waste management. (FI)

  7. Savannah River Laboratory monthly report, November 1991

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, J.M. (comp.)

    1991-01-01

    This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation; tritium facilities and production; separation operations; environmental concerns; and waste management. (FI)

  8. Savannah River Laboratory monthly report, November 1991

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, J.M. [comp.

    1991-12-31

    This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation; tritium facilities and production; separation operations; environmental concerns; and waste management. (FI)

  9. Savannah River Laboratory monthly report, August 1991

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, J.M. [comp.

    1991-12-31

    This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation, tritium facilities and production; separation operations; environmental concerns; and waste management. (FI)

  10. Savannah River Laboratory monthly report, August 1991

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, J.M. (comp.)

    1991-01-01

    This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation, tritium facilities and production; separation operations; environmental concerns; and waste management. (FI)

  11. Chalk as a reservoir

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke

    chalk intervals are to some extent cemented and cannot compact mechanically at realistic effective stresses and only deform elastically. All chalk intervals though, may react by fracturing to changes in shear stress. So where natural fractures are not prevalent, fractures may be generated hydraulically....... Fractures play a significant role in the production of hydrocarbons from chalk reservoirs....

  12. Development and maintenance of a telescoping debris flow fan in response to human-induced fan surface channelization, Chalk Creek Valley Natural Debris Flow Laboratory, Colorado, USA

    Science.gov (United States)

    Wasklewicz, T.; Scheinert, C.

    2016-01-01

    Channel change has been a constant theme throughout William L. Graf's research career. Graf's work has examined channel changes in the context of natural environmental fluctuations, but more often has focused on quantifying channel change in the context of anthropogenic modifications. Here, we consider how channelization of a debris flows along a bajada has perpetuated and sustained the development of 'telescoping' alluvial fan. Two-dimensional debris-flow modeling shows the importance of the deeply entrenched channelized flow in the development of a telescoping alluvial fan. GIS analyses of repeat (five different debris flows), high-resolution (5 cm) digital elevation models (DEMs) generated from repeat terrestrial laser scanning (TLS) data elucidate sediment and topographic dynamics of the new telescoping portion of the alluvial fan (the embryonic fan). Flow constriction from channelization helps to perpetuate debris-flow runout and to maintain the embryonic fan and telescoping nature of the alluvial fan complex. Embryonic fan development, in response to five debris flows, proceeds with a major portion of the flows depositing on the southern portion of the embryonic fan. The third through the fifth debris flows also begin to shift some deposition to the northern portion of the embryonic. The transfer of sediment from a higher portion of the embryonic fan to a lower portion continues currently on the embryonic fan. While channelized flow has been shown to be critical to the maintenance of the telescoping fan, the flow constriction has led to higher than background levels of sediment deposition in Chalk Creek, a tributary of the Arkansas River. A majority of the sediment from each debris flow is incorporated into Chalk Creek as opposed to being stored on the embryonic fan.

  13. Mobile teleoperator research at Savannah River Laboratory

    International Nuclear Information System (INIS)

    A Robotics Technology Group was organized at Savannah River Laboratory to employ modern automation and robotics for applications at the Savannah River site. Several industrial robots have been installed in plant processes. Other robotics systems are under development in the laboratories, including mobile teleoperators for general remote tasks and emergency response operations. This paper discusses present work on a low-cost wheeled mobile vehicle, a modular light duty manipulator arm, a large gantry telerobot system, and a high technology six-legged walking robot with a teleoperated arm

  14. Implementing the AECL decommissioning quality assurance program at the Chalk River and Whiteshell Laboratories

    International Nuclear Information System (INIS)

    This paper describes the approach and progress in developing, implementing and maintaining a quality assurance (QA) program for decommissioning at the nuclear facilities managed by Atomic Energy of Canada Limited (AECL). Decommissioning activities conducted by AECL are varied in nature, so the QA program must provide adequate flexibility, while maintaining consistency with accepted quality standards. Well-written documentation adhering to the applicable decommissioning standards is a key factor. Manager commitment and input during the writing of the documentation are also important to ensure relevance of the QA program and effectiveness of implementation. Training in the use of the quality assurance plan and procedures is vital to the understanding of the QA program. Beyond the training aspect there is a need for the quality assurance program to be supported by a QA subject expert who is able to advise the group in implementing the Quality Program with consistency over the range of decommissioning work activities and to provide continual assessment of the quality assurance program for efficiency and effectiveness, with a concomitant continuous improvement process. (author)

  15. OE Management at Research Technology Operations, Chalk River Laboratories, AECL, Canada

    International Nuclear Information System (INIS)

    Brief description of nuclear facility. A nuclear installation consisting of a 130 MW research reactor and 13 licensed nuclear facilities, staffed by ∼2600 employees, on three distinct sites. Main activities include: (1) Reactor development; (2) CRL nuclear operations; (3) Research and development; (4) Isotope production; (5) Waste management and decommissioning. Overview of OE arrangements. A centralized OE group that is permanently resourced and trained to support the organization. The group is spread over two time zones and supported by a cadre of permanently dedicated OE coordinators and action tracking coordinators throughout the organization

  16. Development and irradiation testing of Al-U3Si2 at Chalk River Laboratories

    International Nuclear Information System (INIS)

    Mini-elements containing Al-64 wt% U3Si2 (3.15 gU/cm3), with three discrete U3Si2 particle-size distributions, have been irradiated up to 93 at% burnup in the NRU reactor. The uranium silicide (U-7.0Si) was used in the as-cast condition, and contained up to 4 wt% free uranium in the U3Si2 matrix. Post-irradiation examinations (PIE) of the high-burnup elements have been recently completed. PIE included underwater and hot-cell examinations, immersion density measurements, neutron radiography, optical and scanning electron microscopy (SEM) with wavelength dispersion X-ray (WDX) analysis, and computerized image analysis of the fission-gas bubble-size distributions. The results show that the Al-U3Si2 swelled less than Al-U3Si fuel previously irradiated under similar conditions in NRU, and no significant swelling dependence on particle-size distribution was observed. Al-U3Si2 core volume increases ranged from 4.2 to 4.7 vol%, compared to 5.8 to 6.8 vol% for Al-U3Si fuel with identical uranium loadings. SEM examinations revealed that the U3Si2 (U-7.0Si) particles contained regions with relatively ordered, very dense populations of sub-micron fission-gas bubbles. In contrast, the gas bubbles are randomly distributed within U3Si (U-3.96Si) particles, vary widely in size, and small bubbles coalesce to form larger bubbles. The capability of U3Si2 to retain fission gas in small bubbles accounts for the lower swelling. (author)

  17. Experience with low-level waste incineration at Chalk River Nuclear Laboratories

    International Nuclear Information System (INIS)

    Construction of a full-scale Waste Treatment Center to volume reduce, stabilize and immobilize CRNL's low-level radioactive wastes for improved storage or disposal is essentially complete. A batch-operated starved-air incinerator for solid combustible waste is one of the processes installed in this facility. Commissioning of this prototype incinerator with inactive waste began in 1980 August and concluded in 1981 December; twenty-two 1-tonne charges (i.e. ''burns'') were completed during that phase. Since then, it has routinely processed most of the current arisings of combustible low-level radioactive waste (LLW) at CRNL. To date, about 1400 m3 of LLW containing up to about 20 mCi/m3 (740 MBq/m3) of mixed activity have been incinerated in 113 burns. Overall performance has remained good during the nearly 3000 h of service with LLW feed. All operational and maintenance functions have been performed without contamination or exposure problems. Particulate beta-gamma stack releases have routinely remained less than 1 /sigma phi/Ci (37 kBq) per burn. The incinerator consistently produces a fully satisfactory inert ash product to an average volume reduction factor greater than 150:1

  18. Savannah River Laboratory monthly report, February 1992

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, J.M. (comp.); Ice, L.W. (ed.)

    1992-02-01

    This report is a progress report for the Savannah River Laboratory for the month of February 1992. The progress and activities in six categories were described in the report. The categories are reactor, tritium, separations, environmental, waste management, and general. Each category described numerous and varied activities. Some examples of these activities described are such things as radiation monitoring, maintenance, modifications, and remedial action.

  19. Model description of CHERPAC (Chalk River Environmental Research Pathways Analysis Code); results of testing with post-Chernobyl data from Finland

    International Nuclear Information System (INIS)

    CHERPAC (Chalk River Environmental Research Pathways Analysis Code), a time-dependent code for assessing doses from accidental and routine releases of radionuclides, has been under development since 1987. A complete model description is provide here with equations, parameter values, assumptions and information on parameter distributions for uncertainty analysis. Concurrently, CHERPAC has been used to participate in the two internal model validation exercises BIOMOVS (BIOspheric MOdel Validation Study) and VAMP (VAlidation of Assessment Model Predictions, a co-ordinated research program of the International Atomic Energy Agency). CHERPAC has been tested for predictions of concentrations of 137Cs in foodstuffs, body burden and dose over time using data collected after the Chernobyl accident of 1986 April. CHERPAC's results for the recent VAMP scenario for southern Finland are particularly accurate and should represent what the code can do under Canadian conditions. CHERPAC's predictions are compared with the observations from Finland for four and one-half years after the accident as well as with the results of the other participating models from nine countries. (author). 18 refs., 23 figs., 2 appendices

  20. Biot Critical Frequency Applied as Common Friction Factor for Chalk with Different Pore Fluids and Temperatures

    DEFF Research Database (Denmark)

    Andreassen, Katrine Alling; Fabricius, Ida Lykke

    2010-01-01

    Injection of water into chalk hydrocarbon reservoirs has lead to mechanical yield and failure. Laboratory experiments on chalk samples correspondingly show that the mechanical properties of porous chalk depend on pore fluid and temperature. Water has a significant softening effect on elastic...... highly influenced by temperature....

  1. Chalk as a reservoir

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke

    Reservoir properties of chalk depend on the primary sediment composition as well as on subsequent diagenesis and tectonic events. Chalks of the North Sea almost exclusively have mudstone or wackestone texture. Microfossils may have retained their porosity where degree of diagenesis is low, or be......, and the best reservoir properties are typically found in mudstone intervals. Chalk mudstones vary a lot though. The best mudstones are purely calcitic, well sorted and may have been redeposited by traction currents. Other mudstones are rich in very fine grained silica, which takes up pore space and...... thus reduces porosity at the same time as it increases specific surface and thus cause permeability to be low. In the Central North Sea the silica is quartzitic. Silica rich chalk intervals are typically found in the Ekofisk and Hod formations. In addition to silica, Upper Cretaceous and Palæogene...

  2. Guide to Savannah River Laboratory Analytical Services Group

    Energy Technology Data Exchange (ETDEWEB)

    1990-04-01

    The mission of the Analytical Services Group (ASG) is to provide analytical support for Savannah River Laboratory Research and Development Programs using onsite and offsite analytical labs as resources. A second mission is to provide Savannah River Site (SRS) operations with analytical support for nonroutine material characterization or special chemical analyses. The ASG provides backup support for the SRS process control labs as necessary.

  3. Overview of environmental research at the Savannah River Laboratory

    International Nuclear Information System (INIS)

    Research in the environmental sciences by the Savannah River Laboratory (SRL) has the general objective of improving our understanding of transport through ecosystems and functional processes within ecosystems. With increased understanding, the basis for environmental assessments can be improved for releases from the Savannah River Plant or from the power industry of the southeastern United States

  4. Guide to Savannah River Laboratory Analytical Services Group

    International Nuclear Information System (INIS)

    The mission of the Analytical Services Group (ASG) is to provide analytical support for Savannah River Laboratory Research and Development Programs using onsite and offsite analytical labs as resources. A second mission is to provide Savannah River Site (SRS) operations with analytical support for nonroutine material characterization or special chemical analyses. The ASG provides backup support for the SRS process control labs as necessary

  5. Dealing with Historical Discrepancies: The Recovery of National Research Experiment (NRX) Reactor Fuel Rods at Chalk River Laboratories (CRL) - 13324

    International Nuclear Information System (INIS)

    Following the 1952 National Research Experiment (NRX) Reactor accident, fuel rods which had short irradiation histories were 'temporarily' buried in wooden boxes at the 'disposal grounds' during the cleanup effort. The Nuclear Legacy Liabilities Program (NLLP), funded by Natural Resources Canada (NRCan), strategically retrieves legacy waste and restores lands affected by Atomic Energy of Canada Limited (AECL) early operations. Thus under this program the recovery of still buried NRX reactor fuel rods and their relocation to modern fuel storage was identified as a priority. A suspect inventory of NRX fuels was compiled from historical records and various research activities. Site characterization in 2005 verified the physical location of the fuel rods and determined the wooden boxes they were buried in had degraded such that the fuel rods were in direct contact with the soil. The fuel rods were recovered and transferred to a modern fuel storage facility in 2007. Recovered identification tags and measured radiation fields were used to identify the inventory of these fuels. During the retrieval activity, a discrepancy was discovered between the anticipated number of fuel rods and the number found during the retrieval. A total of 32 fuel rods and cans of cut end pieces were recovered from the specified site, which was greater than the anticipated 19 fuel rods and cans. This discovery delayed the completion of the project, increased the associated costs, and required more than anticipated storage space in the modern fuel storage facility. A number of lessons learned were identified following completion of this project, the most significant of which was the potential for discrepancies within the historical records. Historical discrepancies are more likely to be resolved by comprehensive historical record searches and site characterizations. It was also recommended that a complete review of the wastes generated, and the total affected lands as a result of this historic 1952 NRX accident be undertaken. These lessons and recommendations have lead to changes in how the NLLP is executed in the CRL waste management areas. (authors)

  6. Permeability prediction in chalks

    DEFF Research Database (Denmark)

    Alam, Mohammad Monzurul; Fabricius, Ida Lykke; Prasad, Manika

    2011-01-01

    The velocity of elastic waves is the primary datum available for acquiring information about subsurface characteristics such as lithology and porosity. Cheap and quick (spatial coverage, ease of measurement) information of permeability can be achieved, if sonic velocity is used for permeability...... prediction, so we have investigated the use of velocity data to predict permeability. The compressional velocity fromwireline logs and core plugs of the chalk reservoir in the South Arne field, North Sea, has been used for this study. We compared various methods of permeability prediction from velocities....... The relationships between permeability and porosity from core data were first examined using Kozeny’s equation. The data were analyzed for any correlations to the specific surface of the grain, Sg, and to the hydraulic property defined as the flow zone indicator (FZI). These two methods use two...

  7. Savannah River Laboratory data banks for risk assessment

    International Nuclear Information System (INIS)

    The Savannah River Laboratory maintains a series of computerized data banks primarily as an aid in probabilistic risk assessment studies for the Savannah River Plant (SRP) facilities. These include component failure rates, generic incidents, and reports of specific deviations from normal operating conditions. In addition to providing data for probability studies, these banks have served as a valuable aid in trend analyses, equipment histories, process hazards analyses, consequence assessments, incident audits, process problem solving, and training

  8. Less chalk more action

    Science.gov (United States)

    Mitriceski Andelkovic, Bojana; Jovic, Sladjana

    2016-04-01

    Less chalk more action Education should not be a mechanical system that operates according to the principles of the orders and implementation. Education should respect the basic laws of the develop and progress. Curiosity is the engine of achievement and children spontaneously and happily learn only if they get interested, if teacher wake up and stimulate their creativity and individuality. We would like to present classes that are realized as thematic teaching with several subjects involved: chemistry, geography, math, art and biology. Classes were organized for students at age from 10 to 13 years, every month during autumn and winter 2015. Better students identified themselves as teachers and presented peer education .Teachers were monitoring the process of teaching and help to develop links between younger and older students, where older students were educators to younger students. Also one student with special needs was involved in this activities and was supported by other students during the workshops The benefit from this project will be represented with evaluation marks. Evaluation table shows that group of ten students(age 10 to13 years) which are selected in October as children with lack of motivation for learning, got better marks, at the end of January , then they had it in the beginning of the semester.

  9. DATA RECOVERY EFFORTS AT IDAHO NATIONAL LABORATORY, OAK RIDGE NATIONAL LABORATORY, AND SAVANNAH RIVER NATIONAL LABORATORY

    Energy Technology Data Exchange (ETDEWEB)

    Richard Metcalf; Saleem Salaymeh; Michael Ehinger

    2010-07-01

    Abstract was already submitted. Could not find the previous number. Would be fine with attaching/update of old number. Abstract Below: Modern nuclear facilities will have significant process monitoring capability for their operators. These systems will also be used for domestic safeguards applications, which has led to research over new diversion-detection algorithms. Curiously missing from these efforts are verification and validation data sets. A tri-laboratory project to locate the existing data sets and recover their data has yielded three major potential sources of data. The first is recovery of the process monitoring data of the Idaho Chemical Processing Plant, which now has a distributable package for algorithm developers. The second data set is extensive sampling and process data from Savannah River National Laboratory’s F- and H-canyon sites. Finally, high fidelity data from the start-up tests at the Barnwell Reprocessing Facility is in recovery. This paper details the data sets and compares their relative attributes.

  10. Detailed river stage mapping and head gradient analysis during meander cutoff in a laboratory river

    Science.gov (United States)

    Han, Bangshuai; Endreny, Theodore A.

    2014-02-01

    Analytical models of river evolution predict meander narrowing and elongation which creates sinuosity-driven hyporheic exchange across the meander neck, by decreasing flow distance and increasing head loss. We used a laboratory river table and close range photogrammetry to map and analyze sinuosity as a driver of head gradients and hyporheic exchange during cutoff. The river valley had relatively high slopes (1.8%) and moderately cohesive sediment (10% talc, 90% sand) to facilitate cutoff, and ratios of horizontal to vertical scaling were distorted to achieve dynamic similitude (Re = 3200). Incipient to cutoff, the head gradient across the neck increased due to a narrowing neck, upstream aggradation, and downstream degradation. Longitudinal and transverse river surface slopes around the meander bend increased as the meander approached cutoff. The steep head gradient across the moderately cohesive meander neck generated seepage erosion and scour that formed a low-sinuosity avulsion. Sediment-rich flow in the avulsed channel aggraded the downstream bed and separated the active channel and oxbow lake. The limitation in geometric and dynamic similitude in the river table limits extrapolation to natural rivers, yet river evolution may involve aggradation and degradation induced channel head loss and turnover hyporheic exchange as well as seepage-induced meander neck erosion. Our submillimeter maps of meander morphology and water stage provide data to parameterize river evolution and hyporheic exchange models, and may inform analysis and mapping of field sites.

  11. Radiation chemistry in the nuclear power reactor environment: from laboratory study to practical application

    International Nuclear Information System (INIS)

    This paper discusses the work carried out at the Chalk River Nuclear Laboratories in underlying and applied radiation chemical research performed to optimise the processes occurring in the four aqueous systems in and around the core. The aqueous systems subject to radiolysis in CANDU reactors are Heat Transport System, Moderator, Liquid Zone Controls and End Shields.

  12. Environmental audit of the Savannah River Ecology Laboratory (SREL)

    International Nuclear Information System (INIS)

    This report documents the results of the environmental audit conducted at the Savannah River Ecology Laboratory (SREL) at the Savannah River Site (SRS), principally in Aiken and Barnwell Counties, South Carolina. The audit was conducted by the US Department of Energy's (DOE's), Office of Environmental Audit (EH-24), beginning September 13, 1993, and ending September 23, 1993. The scope of the audit at SREL was comprehensive, addressing environmental activities in the technical areas of air; surface water/drinking water; groundwater/soil, sediment, and biota; waste management; toxic and chemical materials; inactive Waste sites; radiation; quality assurance; and environmental management. Specifically assessed was the compliance of SREL operations and activities with Federal, state, and local regulations; DOE Orders; and best management practices

  13. Environmental audit of the Savannah River Ecology Laboratory (SREL)

    Energy Technology Data Exchange (ETDEWEB)

    1993-09-01

    This report documents the results of the environmental audit conducted at the Savannah River Ecology Laboratory (SREL) at the Savannah River Site (SRS), principally in Aiken and Barnwell Counties, South Carolina. The audit was conducted by the US Department of Energy`s (DOE`s), Office of Environmental Audit (EH-24), beginning September 13, 1993, and ending September 23, 1993. The scope of the audit at SREL was comprehensive, addressing environmental activities in the technical areas of air; surface water/drinking water; groundwater/soil, sediment, and biota; waste management; toxic and chemical materials; inactive Waste sites; radiation; quality assurance; and environmental management. Specifically assessed was the compliance of SREL operations and activities with Federal, state, and local regulations; DOE Orders; and best management practices.

  14. Environmental information document: Savannah River Laboratory Seepage Basins

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, B.F.; Looney, B.B.; Simmons, R.V.; Bledsoe, H.W.

    1987-03-01

    This document provides environmental information on postulated closure options for the Savannah River Laboratory Seepage Basins at the Savannah River Plant and was developed as background technical documentation for the Department of Energy`s proposed Environmental Impact Statement (EIS) on waste management activities for groundwater protection at the plant. The results of groundwater and atmospheric pathway analyses, accident analysis, and other environmental assessments discussed in this document are based upon a conservative analysis of all foreseeable scenarios as defined by the National Environmental Policy Act (CFR, 1986). The scenarios do not necessarily represent actual environmental conditions. This document is not meant to be used as a closure plan or other regulatory document to comply with required federal or state environmental regulations.

  15. Biot Critical Frequency Applied as Common Friction Factor for Chalk with Different Pore Fluids and Temperatures

    DEFF Research Database (Denmark)

    Andreassen, Katrine Alling; Fabricius, Ida Lykke

    Injection of water into chalk hydrocarbon reservoirs has lead to mechanical yield and failure. Laboratory experiments on chalk samples correspondingly show that the mechanical properties of porous chalk depend on pore fluid and temperature. Water has a significant softening effect on elastic...... we propose that the fluid effect on mechanical properties of highly porous chalk may be the result of liquid‐solid friction. Applying a different strain or stress rate is influencing the rock strength and needs to be included. The resulting function is shown to relate to the material dependent and...... rate independent b-factor used when describing the time dependent mechanical properties of soft rock or soils. As a consequence it is then possible to further characterize the material constant from the porosity and permeability of the rock as well as from pore fluid density and viscosity which is...

  16. A novel representation of chalk hydrology in a land surface model

    Science.gov (United States)

    Rahman, Mostaquimur; Rosolem, Rafael

    2016-04-01

    Unconfined chalk aquifers contain a significant portion of water in the United Kingdom. In order to optimize the assessment and management practices of water resources in the region, modelling and monitoring of soil moisture in the unsaturated zone of the chalk aquifers are of utmost importance. However, efficient simulation of soil moisture in such aquifers is difficult mainly due to the fractured nature of chalk, which creates high-velocity preferential flow paths in the unsaturated zone. In this study, the Joint UK Land Environment Simulator (JULES) is applied on a study area encompassing the Kennet catchment in Southern England. The fluxes and states of the coupled water and energy cycles are simulated for 10 consecutive years (2001-2010). We hypothesize that explicit representation for the soil-chalk layers and the inclusion of preferential flow in the fractured chalk aquifers improves the reproduction of the hydrological processes in JULES. In order to test this hypothesis, we propose a new parametrization for preferential flow in JULES. This parametrization explicitly describes the flow of water in soil matrices and preferential flow paths using a simplified approach which can be beneficial for large-scale hydrometeorological applications. We also define the overlaying soil properties obtained from the Harmonized World Soil Database (HWSD) in the model. Our simulation results are compared across spatial scales with measured soil moisture and river discharge, indicating the importance of accounting for the physical properties of the medium while simulating hydrological processes in the chalk aquifers.

  17. Ekofisk chalk: core measurements, stochastic reconstruction, network modeling and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Talukdar, Saifullah

    2002-07-01

    This dissertation deals with (1) experimental measurements on petrophysical, reservoir engineering and morphological properties of Ekofisk chalk, (2) numerical simulation of core flood experiments to analyze and improve relative permeability data, (3) stochastic reconstruction of chalk samples from limited morphological information, (4) extraction of pore space parameters from the reconstructed samples, development of network model using pore space information, and computation of petrophysical and reservoir engineering properties from network model, and (5) development of 2D and 3D idealized fractured reservoir models and verification of the applicability of several widely used conventional up scaling techniques in fractured reservoir simulation. Experiments have been conducted on eight Ekofisk chalk samples and porosity, absolute permeability, formation factor, and oil-water relative permeability, capillary pressure and resistivity index are measured at laboratory conditions. Mercury porosimetry data and backscatter scanning electron microscope images have also been acquired for the samples. A numerical simulation technique involving history matching of the production profiles is employed to improve the relative permeability curves and to analyze hysteresis of the Ekofisk chalk samples. The technique was found to be a powerful tool to supplement the uncertainties in experimental measurements. Porosity and correlation statistics obtained from backscatter scanning electron microscope images are used to reconstruct microstructures of chalk and particulate media. The reconstruction technique involves a simulated annealing algorithm, which can be constrained by an arbitrary number of morphological parameters. This flexibility of the algorithm is exploited to successfully reconstruct particulate media and chalk samples using more than one correlation functions. A technique based on conditional simulated annealing has been introduced for exact reproduction of vuggy

  18. Biot Critical Frequency Applied to Description of Failure and Yield of Highly Porous Chalk with Different Pore Fluids

    DEFF Research Database (Denmark)

    Andreassen, Katrine Alling; Fabricius, Ida Lykke

    2010-01-01

    nature of dissolved salts have an effect.Water has a significant softening effect on elastic properties of chalk as calculated from wave data, and the softening increases with increasing critical frequency as defined by Biot. The critical frequency is the highest frequency where elastic wave propagation......Injection of water into chalk hydrocarbon reservoirs has led to mechanical yield and failure. Laboratory experiments on chalk samples correspondingly show that the mechanical properties of porous chalk depend on pore fluid and temperature. In case of water-saturated samples, the concentration and...... data include chalk samples that were tested at temperatures from 20 °C to 130 °C with the following pore fluids: fresh water, synthetic seawater, glycol, and oil of varying viscosity. The critical frequency is calculated for each experiment. For each specimen, we calculate the thickness to the slipping...

  19. Testing Of The Radball Technology At Savannah River National Laboratory

    International Nuclear Information System (INIS)

    The United Kingdom's National Nuclear Laboratory (NNL) has developed a remote, nonelectrical, radiation-mapping device known as RadBall (patent pending), which offers a means to locate and quantify radiation hazards and sources within contaminated areas of the nuclear industry. Positive results from initial deployment trials in nuclear waste reprocessing plants at Sellafield in the United Kingdom and the anticipated future potential use of RadBall throughout the U.S. Department of Energy Complex have led to the NNL partnering with the Savannah River National Laboratory (SRNL) to further test, underpin, and strengthen the technical performance of the technology. The study completed at SRNL addresses key aspects of the testing of the RadBall technology. The first set of tests was performed at Savannah River Nuclear Solutions Health Physics Instrument Calibration Laboratory (HPICL) using various gamma-ray sources and an x-ray machine with known radiological characteristics. The objective of these preliminary tests was to identify the optimal dose and collimator thickness. The second set of tests involved a highly contaminated hot cell. The objective of this testing was to characterize a hot cell with unknown radiation sources. The RadBall calibration experiments and hot cell deployment were successful in that for each trial radiation tracks were visible. The deployment of RadBall can be accomplished in different ways depending on the size and characteristics of the contaminated area (e.g., a hot cell that already has a crane/manipulator available or highly contaminated room that requires the use of a remote control device with sensor and video equipment to position RadBall). This report also presents SRNL-designed RadBall accessories for future RadBall deployment (a harness, PODS, and robot).

  20. TESTING OF THE RADBALL TECHNOLOGY AT SAVANNAH RIVER NATIONAL LABORATORY

    Energy Technology Data Exchange (ETDEWEB)

    Farfan, E.; Foley, T.

    2010-02-10

    The United Kingdom's National Nuclear Laboratory (NNL) has developed a remote, nonelectrical, radiation-mapping device known as RadBall (patent pending), which offers a means to locate and quantify radiation hazards and sources within contaminated areas of the nuclear industry. Positive results from initial deployment trials in nuclear waste reprocessing plants at Sellafield in the United Kingdom and the anticipated future potential use of RadBall throughout the U.S. Department of Energy Complex have led to the NNL partnering with the Savannah River National Laboratory (SRNL) to further test, underpin, and strengthen the technical performance of the technology. The study completed at SRNL addresses key aspects of the testing of the RadBall technology. The first set of tests was performed at Savannah River Nuclear Solutions Health Physics Instrument Calibration Laboratory (HPICL) using various gamma-ray sources and an x-ray machine with known radiological characteristics. The objective of these preliminary tests was to identify the optimal dose and collimator thickness. The second set of tests involved a highly contaminated hot cell. The objective of this testing was to characterize a hot cell with unknown radiation sources. The RadBall calibration experiments and hot cell deployment were successful in that for each trial radiation tracks were visible. The deployment of RadBall can be accomplished in different ways depending on the size and characteristics of the contaminated area (e.g., a hot cell that already has a crane/manipulator available or highly contaminated room that requires the use of a remote control device with sensor and video equipment to position RadBall). This report also presents SRNL-designed RadBall accessories for future RadBall deployment (a harness, PODS, and robot).

  1. Self Compacting Concrete with Chalk Filler

    DEFF Research Database (Denmark)

    Sørensen, Eigil V.

    2007-01-01

    Utilisation of Danish chalk filler has been investigated as a means to produce self compacting concrete (SCC) at lower strength levels for service in non aggressive environments. Stable SCC mixtures were prepared at chalk filler contents up to 60% by volume of binder to yield compressive strengths...

  2. Elastic behaviour of North Sea chalk

    DEFF Research Database (Denmark)

    Gommesen, Lars; Fabricius, Ida Lykke; Mukerji, T.;

    2007-01-01

    We present two different elastic models for, respectively, cemented and uncemented North Sea chalk well-log data. We find that low Biot coefficients correlate with anomalously low cementation factors from resistivity measurements at low porosity and we interpret this as an indication of cementation......-saturated North Sea reservoir chalk. In the acoustic impedance–Poisson's ratio plane, we forecast variations in porosity and hydrocarbon saturation from their influence on the elastic behaviour of the chalk. The Gassmann model and the self-consistent approximation give roughly similar predictions of the effect of...... filtrate. The amplitude-versus-angle (AVA) response for the general North Sea sequence of shale overlying chalk is predicted as a function of porosity and pore-fill. The AVA response of both cemented and uncemented chalk generally shows a declining reflectivity coefficient versus offset and a decreasing...

  3. Deep-bed sand filter at Savannah River Laboratory

    International Nuclear Information System (INIS)

    A deep-bed sand filter was placed in service during June 1974 at the Savannah River Laboratory. This filter provides a back-up for HEPA filters in the primary exhaust system. HEPA filters can fail due to deterioration, faulty seating mechanisms, fire, and/or pressure excursions. The deep bed filter area is 103 ft by 140 ft and consists of layers of rock, gravel, and sand to a depth of 7 ft 6 in. Design flow is 74,000 cfm at 5.15 linear fpm. Most of the pressure drop occurs in the 36-in. layer of the ''G'' sand (sieve size No. 50 to No. 30) where the submicron particulates are captured. The filter is described, and operating characteristics are summarized, including pressure drops and filter efficiencies as determined with DOP. (U.S.)

  4. Impact of supercritical CO2 injection on petrophysical and rock mechanics properties of chalk: an experimental study on chalk from South Arne field, North Sea

    DEFF Research Database (Denmark)

    Alam, Mohammad Monzurul; Hjuler, Morten Leth; Christensen, Helle Foged;

    2011-01-01

    Changes in chalk due to EOR by injecting supercritical CO2 (CO2-EOR) can ideally be predicted by applying geophysical methods designed from laboratory-determined petrophysical and rock mechanics properties. A series of petrophysical and rock mechanics tests were performed on Ekofisk Formation and...

  5. Numerical modelling of channel migration with application to laboratory rivers

    Institute of Scientific and Technical Information of China (English)

    Jian SUN; Bin-liang LIN; Hong-wei KUANG

    2015-01-01

    The paper presents the development of a morphological model and its application to experimental model rivers. The model takes into account the key processes of channel migration, including bed deformation, bank failure and wetting and drying. Secondary flows in bends play an important role in lateral sediment transport, which further affects channel migration. A new formula has been derived to predict the near-bed secondary flow speed, in which the magnitude of the speed is linked to the lateral water level gradient. Since only non-cohesive sediment is considered in the current study, the bank failure is modelled based on the concept of submerged angle of repose. The wetting and drying process is modelled using an existing method. Comparisons between the numerical model predictions and experimental observations for various discharges have been made. It is found that the model predicted channel planform and cross-sectional shapes agree generally well with the laboratory observations. A scenario analysis is also carried out to investigate the impact of secondary flow on the channel migration process. It shows that if the effect of secondary flow is ignored, the channel size in the lateral direction will be seriously underestimated.

  6. The North Sea reservoir chalk characterization

    OpenAIRE

    Kallesten, Emanuela

    2015-01-01

    A significant amount of the hydrocarbon production in the North Sea is related to chalk reservoirs. Since 1969, the chalk play remains one of the most important oil sources in Norway. With the initial expected recovery factor 17%, development in technologies and methods contributed to a substantial increase in oil recovery to an approximately 40%. Much of the reserves in place are yet to be extracted, and secondary and tertiary recovery methods need to advance in order to mobilize the remaini...

  7. Chalk: composition, diagenesis and physical properties

    OpenAIRE

    Fabricius, Ida Lykke

    2007-01-01

    Chalk is a sedimentary rock of unusually high homogeneity on the scale where physical properties are measured, but the properties fall in wide ranges. Chalk may thus be seen as the ideal starting point for a physical understanding of rocks in general. Properties as porosity, permeability, capillary entry pressure, and elastic moduli are consequences of primary sediment composition and ofsubsequent diagenetic history as caused by microbial action, burial stress, temperature, and pore pressure....

  8. Subsidence and capillary effects in chalks

    OpenAIRE

    Delage, Pierre; Schroeder, Christian; Cui, Yu-Jun

    1996-01-01

    Based on the concepts of the mechanics of unsaturated soils where capillary phenomena arise between the wetting fluid (water) and the non-wetting one (air), the subsidence of chalks containing oil (non-wetting fluid) during water injection (wetting fluid) is analysed. It is shown that the collapse phenomenon of unsaturated soils under wetting provides a physical explanation and a satisfactory prediction of the order of magnitude of the subsidence of the chalk. The use of a well established co...

  9. Canada enters the nuclear age: a technical history of Atomic Energy of Canada limited as seen from its research laboratories

    International Nuclear Information System (INIS)

    A technical history of Atomic Energy of Canada Limited written by sixteen of Canada's pioneering nuclear scientists, Canada Enters the Nuclear Age focuses on Canada's nuclear program at AECL's laboratories at Chalk River, Ontario and Whiteshell, Manitoba between the years 1943 and 1985. Topics include the organization and operations of AECL's laboratories, nuclear safety and radiation protection, radioisotopes, basic research, development of the CANDU reactor, and management of radioactive wastes. 7 tabs., 132 figs

  10. Savannah River Laboratory seepage basins: Environmental information document

    International Nuclear Information System (INIS)

    The basins are located in the northwestern section of the Savannah River Plant in the 700 Area. The four basins are out of service and are awaiting closure. When in operation, the basins received a total of 128,820 m3 of low-level radioactive wastewater from laboratories located in Buildings 735-A and 773-A. Wastewater with radioactivity less than 100 d/m/mL alpha and/or 50 d/m/mL beta-gamma was discharged to the basins. Low concentrations of radioactive and nonradioactive constituents were found in the sediments beneath the seepage basins and a statistical analysis of monitoring data from the six water-table wells indicates elevated levels of chloride, manganese, and sodium in the groundwater. The closure options considered for the basins are waste removal and closure, no waste removal and closure, and no action. The environmental impact evaluation indicates that the human health risks for all closure options are low. Radioactive risk is dominated by tritium, but there is no significant difference between the closure options because the tritium has leached from the site prior to the closure action. The most significant noncarcinogenic risk results from arsenic. All atmospheric and occupational risks are low. The primary calculated ecological effect is due to direct contact with the basin sediments in the no action option. The relative costs for the various options are $9 million for waste removal and closure, $2.9 million for no waste removal and closure with cap, $2.4 million for no waste removal and closure without cap, and $0.26 million for no action. 36 refs., 27 figs., 98 tabs

  11. Grain size distributions of chalk from image analysis of electron micrographs

    DEFF Research Database (Denmark)

    Røgen, Birte; Gommesen, Lars; Fabricius, Ida Lykke

    2001-01-01

    from image analysis due to rim effects inherent in backscatter images at high magnification. Thus, in order to obtain a consistent interpretation, we use total (He) porosity and insoluble residue as measured in the laboratory. We find that the volume density of larger grains (cross section larger than...... image analysis. The chalk is composed of a fine-grained matrix of nannofossils and predominantlycalcitic fossil debris with larger microfossil grains, but the chalk may also contain significant amounts of silica and siliciclastic clay. For image analysis, we used backscatter electron images of epoxy...

  12. Measuring and Modeling the Displacement of Connate Water in Chalk Core Plugs during Water Injection

    DEFF Research Database (Denmark)

    Korsbech, Uffe C C; Aage, Helle Karina; Andersen, Bertel Lohmann; Hedegaard, Kathrine; Springer, Niels

    2006-01-01

    The movement of connate water spiked with gamma emitting 22Na was studied during laboratory water flooding of oil saturated chalk from a North Sea oil reservoir. Using a one dimensional gamma monitoring technique is was observed that connate water is piled-up at the front of the injection water and...... forms a mixed water bank with almost 100% connate water in the front behind which a gradual transition to pure injection water occurs. This result underpins log interpretations from waterflooded chalk reservoirs. An ad hoc model was set up by use of the results, and the process was examined...

  13. Canada's Neutron Beam Laboratory

    International Nuclear Information System (INIS)

    This paper describes the current and planned activities of Canada's Neutron Beam Laboratory which is managed by the National Research Council of Canada. In 1994, Professor Bertram Brockhouse shared the Nobel Prize in Physics for his pioneering work carried out in this laboratory. He developed neutron scattering as a powerful and versatile tool for investigating materials at the level of molecules and nano structures. The neutron source for this work is Canada's NRU reactor located at the Chalk River Nuclear Laboratories of the Atomic Energy of Canada Limited. This neutron source is also used for the production of medical isotopes, testing of components for the nuclear power stations and neutron scattering experiments on materials

  14. Measuring and Modeling the Displacement of Connate Water in Chalk Core Plugs during Water Injection

    DEFF Research Database (Denmark)

    Korsbech, Uffe C C; Aage, Helle Karina; Andersen, Bertel Lohmann;

    2006-01-01

    The movement of connate water spiked with gamma emitting 22Na was studied during laboratory water flooding of oil saturated chalk from a North Sea oil reservoir. Using a one dimensional gamma monitoring technique is was observed that connate water is piled-up at the front of the injection water a...

  15. Adsorption of hydrocarbons in chalk reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Madsen, L.

    1996-12-31

    The present work is a study on the wettability of hydrocarbon bearing chalk reservoirs. Wettability is a major factor that influences flow, location and distribution of oil and water in the reservoir. The wettability of the hydrocarbon reservoirs depends on how and to what extent the organic compounds are adsorbed onto the surfaces of calcite, quartz and clay. Organic compounds such as carboxylic acids are found in formation waters from various hydrocarbon reservoirs and in crude oils. In the present investigation the wetting behaviour of chalk is studied by the adsorption of the carboxylic acids onto synthetic calcite, kaolinite, quartz, {alpha}-alumina, and chalk dispersed in an aqueous phase and an organic phase. In the aqueous phase the results clearly demonstrate the differences between the adsorption behaviour of benzoic acid and hexanoic acid onto the surfaces of oxide minerals and carbonates. With NaCl concentration of 0.1 M and with pH {approx_equal} 6 the maximum adsorption of benzoic acid decreases in the order: quartz, {alpha}-alumina, kaolinite. For synthetic calcite and chalk no detectable adsorption was obtaind. In the organic phase the order is reversed. The maximum adsorption of benzoic acid onto the different surfaces decreases in the order: synthetic calcite, chalk, kaolinite and quartz. Also a marked difference in adsorption behaviour between probes with different functional groups onto synthetic calcite from organic phase is observed. The maximum adsorption decreases in the order: benzoic acid, benzyl alcohol and benzylamine. (au) 54 refs.

  16. Chalk Formations as Natural Barriers towards Radionuclide Migration

    DEFF Research Database (Denmark)

    Pedersen, Walther Batsberg; Carlsen, Lars; Jensen, Bror Skytte

    1985-01-01

    A series of chalk samples from the cretaceous formation overlying the Erslev salt dome have been studied in order to establish permeabilities, porosities, dispersion-, diffusion-, and sorption characteristics of the chalk. The chalk was found to be porous (∊≈0.4), however, of rather low permeabil...

  17. Microdeformation and subcritical cracking in chalk

    Science.gov (United States)

    Bergsaker, Anne; Dysthe, Dag Kristian

    2016-04-01

    Deformation processes in chalks, both in relation to changing pore fluids and stress conditions has been of great interest as chalk is an important reservoir rock for both hydrocarbons and ground water. Lately it has also gained interest as a potential reservoir rock for captured CO2. Chalks are composed of large amounts of biogenic calcite grains, the skeletal debris of marine microorganisms. Its deformation is highly time and stress dependent, and governed by a transition from distributed to localized deformation at the onset of yield, affected by mechanisms such as subcritical crack growth and pore collapse. We present a microdeformation rig which makes use of thermal expansion as a means of subjecting small samples to strictly controlled tensile stresses. High resolution imaging provides resolutions down to 0.5 micrometers, enabling study of pore scale processes during slow deformation. Examples of localized and distributed deformation are presented.

  18. Elastic behaviour of North Sea chalk

    DEFF Research Database (Denmark)

    Gommesen, Lars; Fabricius, Ida Lykke; Mukerji, T.;

    2007-01-01

    We present two different elastic models for, respectively, cemented and uncemented North Sea chalk well-log data. We find that low Biot coefficients correlate with anomalously low cementation factors from resistivity measurements at low porosity and we interpret this as an indication of cementation...... self-consistent approximation, which here represents the unrelaxed scenario where the pore spaces of the rock are assumed to be isolated, and the Gassmann theory, which assumes that pore spaces are connected, as tools for predicting the effect of hydrocarbons from the elastic properties of brine......-saturated North Sea reservoir chalk. In the acoustic impedance–Poisson's ratio plane, we forecast variations in porosity and hydrocarbon saturation from their influence on the elastic behaviour of the chalk. The Gassmann model and the self-consistent approximation give roughly similar predictions of the effect of...

  19. Adsorption Properties of Chalk Reservoir Materials

    DEFF Research Database (Denmark)

    Okhrimenko, Denis

    Understanding adsorption energetics and wetting properties of calcium carbonate surfaces is essential for developing remediation strategies for aquifers, improving oil recovery, minimising risk in CO2 storage and optimising industrial processes. This PhD was focussed on comparing the vapour....../gas adsorption properties of synthetic calcium carbonate phases (calcite, vaterite and aragonite) with chalk, which is composed of biogenic calcite (>98%). In combination with data from nanotechniques, the results demonstrate the complexity of chalk behavior and the role of nanoscale clay particles. The results...

  20. Late Maastrichtian chalk mounds, Stevns Klint, Denmark

    DEFF Research Database (Denmark)

    Anderskouv, Kresten; Damholt, Tove; Surlyk, Finn

    controlling the depositional thickness variation across a mound and thus mound growth pattern. Relatively long wave-length wavy-bedded chalk shows gentle convex-up geometries and would probably be described as sediment waves if recognized in seismic sections. The chalk waves were deposited under weaker......-member processes: those that were purely physical and related to the interaction between available grain sizes and hydrodynamics, and those that were largely biological and associated with benthic growth and sediment trapping mainly by bryozoans. The succession was deposited on the upper part of the flank of a 3...

  1. Late Maastrichtian chalk mounds, Stevns Klint, Denmark

    DEFF Research Database (Denmark)

    Anderskouv, Kresten; Damholt, Tove; Surlyk, Finn

    2007-01-01

    determine depositional thickness across a mound and thus mound growth pattern. Relatively long wavelength wavy-bedded chalk show gentle convex-up geometries and would probably be described as sediment waves if recognized in seismic sections. The chalk waves were deposited under weaker current velocities...... the depositional architecture indicates a complex and   dynamic environment. The depositional style seems to be controlled by the interplay and relative importance of two end-member processes; those that were purely physical and related to the interaction between available grain sizes and...

  2. Aquifer properties of the Chalk of England

    OpenAIRE

    MacDonald, Alan M.; Allen, David J

    2001-01-01

    Aquifer properties data from 2100 pumping tests carried out in the Chalk aquifer have been collated as part of a joint British Geological Survey/Environment Agency project. The dataset is highly biased: most pumping tests have been undertaken in valley areas where the yield of the Chalk is highest. Transmissivity values from measured sites give the appearance of log-normality, but are not truly log-normal. The median of available data is 540 m2/d and the 25th and 75th percentiles 190 m2/d and...

  3. Chalk aquifer study : permeability and fractures in the English Chalk : a review of hydrogeological literature

    OpenAIRE

    Allen, D J

    1995-01-01

    The purpose of this report is to provide a review of the hydrogeological literature concerning the hydraulically significant fractures in the Chalk aquifer in England. The review discusses only the effect of the fractures on the permeability of the aquifer; it does not address the question of storage, nor the properties of the matrix. The report charts the evolution of ideas regarding the nature, occurrence and causes of hydraulically significant fractures in the Chalk and atte...

  4. Installation and test results of a high-power, CW klystrode amplifier at Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    The Chalk River Laboratory (CRL) 1.25 MeV, 267 MHz CW radio frequency quadrupole (RFQ) project has been moved to Los Alamos AOT Division as a collaborative effort between Los Alamos and Chalk River Laboratories. The RF part of this project includes two 267 MHz, 0.25 MW, CW klystrode transmitters. The klystrode is a relatively new type of RF source that combines the input structure from a conventional gridded tube and the output structure of a klystron. It is widely used within the UHF television band at reduced power (60 kW at peak of sync). However, this is the first application of a high power klystrode for a particle accelerator. This paper will describe the experimental configuration at Los Alamos, provide block diagrams of the klystrode transmitter, discuss the attributes of the klystrode which make it a desirable candidate for high efficiency CW accelerators, and present relevant test results

  5. Poroelasticity of high porosity chalk under depletion

    DEFF Research Database (Denmark)

    Andreassen, Katrine Alling; Fabricius, Ida Lykke

    2013-01-01

    The theory of poroelasticity for the elastic region below pore collapse by means of three different loading paths gives the possibility to compare the static and dynami-cally determined Biot coefficient for a set of experimental data with uniaxial loading on outcrop chalk performed with different...

  6. Slope failure of chalk channel margins

    DEFF Research Database (Denmark)

    Gale, A.; Anderskouv, Kresten; Surlyk, Finn;

    2015-01-01

    The importance of mass transport and bottom currents is now widely recognized in the Upper Cretaceous Chalk Group of Northern Europe. The detailed dynamics and interaction of the two phenomena are difficult to study as most evidence is based on seismic data and drill core. Here, field observations...

  7. Nickel adsorption on chalk and calcite

    DEFF Research Database (Denmark)

    Belova, Dina Alexandrovna; Lakshtanov, Leonid; Carneiro, J.F.;

    2014-01-01

    Nickel uptake from solution by two types of chalk and calcite was investigated in batch sorption studies. The goal was to understand the difference in sorption behavior between synthetic and biogenic calcite. Experiments at atmospheric partial pressure of CO2, in solutions equilibrated with calcite...

  8. Solute transport in the unsaturated zone of the Chalk

    International Nuclear Information System (INIS)

    Groundwater is a major source of public supply in England and Wales, where it meets about 30% of the demand. In some areas, particularly south-east England, it is the major source. Much concern has been expressed in recent years about the pollution of groundwater resources by nitrates, and the Water Research Centre has undertaken an extensive programme of drilling and sampling to determine the reason for the rise in nitrate levels and to assess future trends. To assist with the interpretation of field data, mechanisms of water and solute movement through the unsaturated zone have been investigated, and the Chalk, our major aquifer, has received particular attention. The dating of groundwater by tritium measurements has led to considerable speculation regarding flow processes in the Chalk, and the additional information gained from the nitrates investigations has led to the formulation of a flow model in which water and its solutes move at very different velocities. It has been deduced that in the unsaturated zone water moves downwards through the fissure system at about 0.7 m/d, while any solutes carried from the land surface move downwards at about 1 m/a. Laboratory experiments have yielded evidence in support of this hypothesis, though further research is needed before a comprehensive model of the flow mechanism can be established. A similar flow mechanism is expected to be operative in many other aquifers, and has important implications for groundwater pollution trends. (author)

  9. Rock physical aspects of CO{sub 2} injection in chalk

    Energy Technology Data Exchange (ETDEWEB)

    Alam, M.M.

    2011-04-15

    Impact of supercritical CO{sub 2} on the petrophysical and rock-mechanics properties of Ekofisk Formation and Tor Formation chalk from South Arne field, Danish North Sea, chalk was investigated. A series of laboratory experiments was performed on core material collected from the reservoir zone of the South Arne field in order to reveal the changes with respect to porosity, specific surface, pore stiffness, wettability, mineralogy and mechanical failure. In addition, a theoretical rock physical background was also established in order to be able to make sensible interpretation of laboratory data. Sound wave velocity was used as the central tool to study any change in petrophysical and rock mechanical properties. The main focus was to achieve a better understanding of effective stress coefficient (also known as Biot's coefficient); by means of which effective stress can be predicted more accurately. Independent theoretical studies were made on diagenesis, surface properties and stiffness of chalk and their relation with sonic velocity (or Biot's coefficient calculated from sonic velocity). The knowledge and experience from these studies was combined to achieve the main research objective of monitoring changes in hydrocarbon reservoirs in chalk due to CO{sub 2} injection. In order to understand the development of chalk from calcareous ooze and achieving pore stiffness, the diagenesis process of a sedimentary sequence from Kerguelen Plateau in the Indian Ocean was studied. The principal objective of the study was to explore how different porosity reduction mechanisms change the strength of these deep sea carbonate-rich sediments and how these mechanisms can be traced from the change in Biot's coefficient, alpha. In calcareous ooze, alpha was found close to one. Mechanical compaction reduces porosity, but only leads to a minor decrease in alpha. Recrystallization process renders particles smoother, but do not lead to reduction in alpha unless it gives

  10. Ecological research at the Savannah River Ecology Laboratory. Annual report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-05-01

    Research is organized around two major programs: thermal and aquatic stress and mineral cycling. These programs are strengthened by a previously established foundation of basic ecological knowledge. Research in basic ecology continues to be a major component of all SREL environmental programs. Emphasis in all programs has been placed upon field-oriented research relating to regional and local problems having broad ecological significance. For example, extensive research has been conducted in the Par Pond reservoir system and the Savannah River swamp, both of which have received thermal effluent, heavy metals, and low levels of radioisotopes. Furthermore, the availability of low levels of plutonium and uranium in both terrestrial and aquatic environments on the Savannah River Plant (SRP) has provided an unusual opportunity for field research in this area. The studies seek to document the effects, to determine the extent of local environmental problems, and to establish predictable relationships which have general applicability. In order to accomplish this objective it has been imperative that studies be carried out in the natural, environmentally unaffected areas on the SRP as a vital part of the overall program. Progress is reported in forty-nine studies.

  11. Competitive sorption of organic contaminants in chalk

    Science.gov (United States)

    Graber, E. R.; Borisover, M.

    2003-12-01

    In the Negev desert, Israel, a chemical industrial complex is located over fractured Eocene chalk formations where transfer of water and solutes between fracture voids and matrix pores affects migration of contaminants in the fractures due to diffusion into the chalk matrix. This study tests sorption and sorption competition between contaminants in the chalk matrix to make it possible to evaluate the potential for contaminant attenuation during transport in fractures. Single solute sorption isotherms on chalk matrix material for five common contaminants ( m-xylene, ametryn, 1,2-dichloroethane, phenanthrene, and 2,4,6-tribromophenol) were found to be nonlinear, as confirmed in plots of Kd versus initial solution concentration. Over the studied concentration ranges, m-xylene Kd varied by more than a factor of 100, ametryn Kd by a factor of 4, 1,2-dichloroethane Kd by more than a factor of 3, phenanthrene Kd by about a factor of 2, and 2,4,6-tribromophenol Kd by a factor of 10. It was earlier found that sorption is to the organic matter component of the chalk matrix and not to the mineral phases (Chemosphere 44 (2001) 1121). Nonlinear sorption isotherms indicate that there is at least some finite sorption domain. Bi-solute competition experiments with 2,4,6-tribromophenol as the competitor were designed to explore the nature of the finite sorption domain. All of the isotherms in the bi-solute experiments are more linear than in the single solute experiments, as confirmed by smaller variations in Kd as a function of initial solution concentration. For both m-xylene and ametryn, there is a small nonlinear component or domain that was apparently not susceptible to competition by 2,4,6-tribromophenol. The nonlinear sorption domain(s) is best expressed at low solution concentrations. Inert-solvent-normalized single and bi-solute sorption isotherms demonstrate that ametryn undergoes specific force interactions with the chalk sorbent. The volume percent of phenanthrene

  12. Analysis of ground water from boreholes, river water and precipitation in the Underground Research Laboratory project

    International Nuclear Information System (INIS)

    In the Horonobe Underground Research Laboratory (URL) Project, ground water from boreholes, river water and precipitation have been periodically analyzed for the environmental monitoring since the fiscal year 2001. This report shows the data set of water chemistry since the fiscal year 2001 to the fiscal year 2006. (author)

  13. Effect of Fluid Dynamic Viscosity on the Strength of Chalk

    DEFF Research Database (Denmark)

    Hedegaard, K.; Fabricius, Ida Lykke

    The mechanical strength of high porosity and weakly cemented chalk is affected by the fluid in the pores. In this study, the effect of the dynamic viscosity of non-polar fluids has been measured on outcrop chalk from Sigerslev Quarry, Stevns, Denmark. The outcome is that the measured strength of...... the chalk decreases with increasing dynamic viscosity. The proposed qualitative explanation is that pressure difference supports and enhances the generation of microscopic shear and tensile failures....

  14. Water in chalk reservoirs: 'friend or foe?'

    International Nuclear Information System (INIS)

    Most of the petroleum fields in the Norwegian sector of the North Sea are sandstone reservoirs; the oil and gas are trapped in different species of sandstone. But the Ekofisk Field is a chalk reservoir, which really challenges the operator companies. When oil is produced from chalk reservoirs, water usually gets in and the reservoir subsides. The subsidence may be expensive for the oil companies or be used to advantage by increasing the recovery rate. Since 60 per cent of the world's petroleum reserves are located in carbonate reservoirs, it is important to understand what happens as oil and gas are pumped out. Comprehensive studies at the Department of Petroleum Technology and Applied Geophysics at Stavanger University College in Norway show that the mechanical properties of chalk are considerably altered when the pores in the rock become saturated with oil/gas or water under different stress conditions. The processes are extremely complex. The article also maintains that the effects of injecting carbon dioxide from gas power plants into petroleum reservoirs should be carefully studied before this is done extensively

  15. Construction of the Savannah River Ecology Laboratory Conference Center

    International Nuclear Information System (INIS)

    This Environmental Assessment (EA) reviews the environmental consequences associated with the proposed action of granting a site use permit to construct and operate a conference center on an approximately 70-acre tract of land on the Savannah River Site (SRS). While the proposed action requires an administrative decision by DOE, this EA reviews the linked action of physically constructing and operating a conference center. The SRS is a DOE-owned nuclear production facility encompassing approximately 200,000 acres in southwestern South Carolina. The proposed conference center would have an area of approximately 4,000 square feet, and would infrequently accommodate as many as 150 people, with the average being about 20 people per day. In addition to the No-Action alternative, under which the Research Foundation would not require the 70-acre tract of SRS land for a conference center, this EA considers site preservation. Under Site Preservation only minimal activities necessary to the SRS mission would occur, thereby establishing the lower limits of environmental consequences. A review conducted under the SRS permitting process identified no other forms of possible site development. Similarly, SRS areas identified in the Nuclear Complex Reconfiguration Site Proposal (DOE, 199la) do not include the conference center site area in proposed weapons complex reconfiguration activities. As a consequence, this EA does not consider other forms of possible site development as alternatives. The potential environmental consequences associated with the action of constructing and operating a conference center include impacts to cultural resources and impacts from construction activities, primarily related to land clearing (5 to 10 acres) and providing access to the site

  16. Deep saltwater in Chalk of North-West Europe: origin, interface characteristics and development over geological time

    DEFF Research Database (Denmark)

    Bonnesen, Ellen Prip; Larsen, F.; Sonnenborg, T.O.;

    2009-01-01

    location, saline water in the Chalk resides at depths from 40 to 80m and salinity increases with depth. Concentrations of chloride up to ca. 30,000ppm have been observed at depths of 400m. Measured vertical hydraulic heads in open boreholes suggest that advective groundwater flow is now restricted in...... deeper parts of the Chalk formation and diffusive transport is thus the predominant transport mechanism. Laboratory-measured porosity and effective diffusion coefficients were used as input to a numerical 1D diffusion model of the interface between freshwater in an upper, fractured aquifer and modified...

  17. Compaction of microfossil and clay-rich chalk sediments

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke

    2001-01-01

    The aim of this study was to evaluate the role of microfossils and clay in the compaction of chalk facies sediments. To meet this aim, chalk sediments with varying micro texture were studied. The sediments have been tested uniaxially confined in a stainless-steel compaction cell. The sediments ar...

  18. Compaction of North-sea chalk

    Science.gov (United States)

    Keszthelyi, Dániel; Dysthe, Dag Kristian; Jamtveit, Bjørn

    2014-05-01

    The Ekofisk field is the largest petroleum field in the Norwegian North Sea territory where oil is produced from chalk formations. Early stage of oil production caused considerable changes in pore fluid pressure which led to a reservoir compaction. Pore collapse mechanism caused by the dramatic increase of effective stress, which in turn was caused by the pressure reduction by hydrocarbon depletion, was early identified as a principal reason for the reservoir compaction (Sulak et al. 1991). There have been several attempts to model this compaction. They performed with variable success on predicting the Ekofisk subsidence. However, the most of these models are based on empirical relations and do not investigate in detail the phenomena involved in the compaction. In sake of predicting the Ekofisk subsidence while using only independently measurable variables we used a chalk compaction model valid on geological time-scales (Japsen et al. 2011) assuming plastic pore-collapse mechanism at a threshold effective stress level. We identified the phenomena involved in the pore collapse. By putting them in a sequential order we created a simple statistical analytical model. We also investigated the time-dependence of the phenomena involved and by assuming that one of the phenomena is rate-limiting we could make estimations of the compaction rate at smaller length-scales. By carefully investigating the nature of pressure propagation we could upscale our model to reservoir scale. We found that the predicted compaction rates are close enough to the measured rates. We believe that we could further increase accuracy by refining our model. Sulak, R. M., Thomas, L. K., Boade R. R. (1991) 3D reservoir simulation of Ekofisk compaction drive. Journal of Petroleum Technology, 43(10):1272-1278, 1991. Japsen, P., Dysthe, D. K., Hartz, E. H., Stipp, S. L. S., Yarushina, V. M., Jamtveit. (2011) A compaction front in North Sea chalk. Journal of Geophysical Research: Solid Earth (1978

  19. Chalk effect on PVC cross-linking under irradiation

    International Nuclear Information System (INIS)

    Effect of nonmodified and modified chalk on curing degree of polymer matrix was studied under-irradiation of PVC-compositions. Films of the compositions (100 mass part 7 PVC, 0-100 mas.part of chalk, 2.5 - lead sulfate, 1.5 - lead stearate and 0.3 - glycerin) were irradiated up to absorbed dose 0.1 MGy in an inert medium. Content of gel-fraction after boiling in THF was determined with use of IR spectroscopy. It was established, that intensive dehydrochlorination and polymer curing took place on chalk particle surface. Network fixed strongly chalk particles. However, chalk inhibited processes of dehydrochlorination and PVC curing, increasing amount of noncured PVC in polymer matrix

  20. Savannah River Laboratory environmental transport and effects research. Annual report, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, T.V. (comp.)

    1979-11-01

    Research in the environmental sciences by the Savannah River Laboratory during 1978 is described in 43 articles. These articles are in the fields of terrestrial ecology, geologic studies, aquatic transport, aquatic ecology, atmospheric transport, emergency response, computer methods development, ocean program, and fuel cycle program. Thirty-seven of the articles were abstracted individually for ERA/EDB; those in scope were also included in INIS.

  1. A laboratory based experimental study of mercury emission from contaminated soils in the River Idrijca catchment

    OpenAIRE

    D. Kocman; Horvat, M.

    2010-01-01

    Results obtained by a laboratory flux measurement system (LFMS) focused on investigating the kinetics of the mercury emission flux (MEF) from contaminated soils of the Idrija Hg-mine region, Slovenia are presented. Representative soil samples with respect to total Hg concentrations (4–417 μg g−1) and land cover (forest, meadow and alluvial soil) alongside the River Idrijca were analysed to determine the variation in MEF versus distance from the source, ...

  2. Savannah River Laboratory data banks for risk assessment of fuel reprocessing plants

    International Nuclear Information System (INIS)

    The Savannah River Laboratory maintains a series of computerized data banks primarily as an aid in probabilistic risk assessment studies in the fuel reprocessing facilities. These include component failure rates, generic incidents, and reports of specific deviations from normal operating conditions. In addition to providing data for probability studies, these banks, have served as a valuable aid in trend analysis, equipment histories, process hazards analysis, consequence assessments, incident audit, process problem solving, and training

  3. The Finnis River. A natural laboratory of mining impact- past, present and future

    International Nuclear Information System (INIS)

    The Rum Jungle uranium-copper mine in tropical northern Australia has been a source of acid rock drainage contaminants since the 1950s, which have had adverse impacts on the receiving waters of the Finniss River. Mine site remediation began in 1982 followed by long-term monitoring of water quality and flow, based on daily measurements within the Finniss River system. A decade or more after the initiation of these remedial activities, a set of investigations have been completed that have measured the post-remedial ecological status of the Finniss River system, relative to this environmental benchmark. These studies have also been complemented by studies on various other ecological endpoints. Moreover, the Finniss River system has provided unique opportunities for broader scientific goals to be pursued. Because it has been so well-monitored, it can be viewed as a natural laboratory to investigate the impacts of acid rock drainage on tropical freshwater biodiversity. The scientific papers presented at this symposium address a broad spectrum of issues that are directly related to environmental sustainability and mining. The topics range across future contaminant scenarios and their predicted ecological impacts, the various metrics used to assess ecological detriment to biodiversity, the abilities of laminated biological structures to act as archives of pollution history, and also spin-off applications in environmental and wildlife management. Furthermore, the participation of many stakeholders in open discussion during the symposium provided an important set of views and opinions on the needs for future studies in the Finniss River system

  4. Controls on the spatial and temporal variability of Rn-222 in riparian groundwater in a lowland Chalk catchment.

    OpenAIRE

    Mullinger, Neil J.; Pates, Jackie M.; Binley, Andrew M.; Crook, N. P.

    2009-01-01

    Radon is a powerful tracer of stream-aquifer interactions. However, it is important to consider the source and behaviour of radon in groundwater when interpreting observations of river radon in relation to groundwater discharge. Here we characterise the variability in groundwater radon concentrations in the riparian zone of a Chalk catchment. Groundwater 222Rn (radon) concentrations were determined in riparian zone boreholes at two sites in the Lambourn catchment, Berkshire, UK, over a two ye...

  5. ELECTRONICS UPGRADE TO THE SAVANNAH RIVER NATIONAL LABORATORY COULOMETER FOR PLUTONIUM AND NEPTUNIUM ASSAY

    Energy Technology Data Exchange (ETDEWEB)

    Cordaro, J.; Holland, M.; Reeves, G.; Nichols, S.; Kruzner, A.

    2011-07-08

    The Savannah River Site (SRS) has the analytical measurement capability to perform high-precision plutonium concentration measurements by controlled-potential coulometry. State-of-the-art controlled-potential coulometers were designed and fabricated by the Savannah River National Laboratory and installed in the Analytical Laboratories process control laboratory. The Analytical Laboratories uses coulometry for routine accountability measurements of and for verification of standard preparations used to calibrate other plutonium measurement systems routinely applied to process control, nuclear safety, and other accountability applications. The SRNL Coulometer has a demonstrated measurement reliability of {approx}0.05% for 10 mg samples. The system has also been applied to the characterization of neptunium standard solutions with a comparable reliability. The SRNL coulometer features: a patented current integration system; continuous electrical calibration versus Faraday's Constants and Ohm's Law; the control-potential adjustment technique for enhanced application of the Nernst Equation; a wide operating room temperature range; and a fully automated instrument control and data acquisition capability. Systems have been supplied to the International Atomic Energy Agency (IAEA), Russia, Japanese Atomic Energy Agency (JAEA) and the New Brunswick Laboratory (NBL). The most recent vintage of electronics was based on early 1990's integrated circuits. Many of the components are no longer available. At the request of the IAEA and the Department of State, SRNL has completed an electronics upgrade of their controlled-potential coulometer design. Three systems have built with the new design, one for the IAEA which was installed at SAL in May 2011, one system for Los Alamos National Laboratory, (LANL) and one for the SRS Analytical Laboratory. The LANL and SRS systems are undergoing startup testing with installation scheduled for this summer.

  6. Self-formed Dynamic Meandering Rivers and Floodplains in the Laboratory: Necessary and Sufficient Conditions

    Science.gov (United States)

    Kleinhans, M. G.; van Dijk, W. M.; van de Lageweg, W. I.; Markies, H.; van der Gon-Netscher, T.; van de Meer, H.; van Maarseveen, M.; Postma, G.

    2010-12-01

    Traditionally, rivers were downscaled to the laboratory through similarity of the Froude, Shields and Reynolds numbers. This has worked well for rivers with fixed banks and for braided gravel-bed rivers. However, for self-formed dynamic meandering rivers in experiments, Froude scaling is incomplete without a constrained width-depth ratio. This aspect ratio should be small enough to obtain alternate bars. Bank erosion and bar migration have to be limited by somewhat cohesive or vegetated self-formed floodplains. Our objective is to determine the conditions that lead to river meandering in the laboratory. We developed an experimental scaling strategy for meandering gravel-bed rivers that reduces scale problems or quantifies scale effects. A sediment mixture ranging from silt to fine gravel produces subcritical to critical flow, a hydraulically rough boundary without scour holes or current ripples. Furthermore the mixture leads to richer morphodynamics with measurable sorting trends, narrower channels and cohesive self-formed floodplains. We cycle the inflow point of constant flow discharge and sediment feed in transverse direction at the upstream boundary to perturb an initially straight channel and simulate a meander migrating into the flume (Van Dijk et al., this conference). The downstream boundary is a lake into which the river progrades a branched fan delta (Villiers et al., Cheshier et al., van de Lageweg et al., this conference). Morphology was recorded by high-resolution line-laser scanning and digital photography allowed image segmentation and particle size estimation through an entropy method. In agreement with earlier work, the experimental river initially evolves from alternate bars to a fully braided river without significant floodplain building. With silica flour added to the feed, a transitional river between braided and meandering evolves with frequent chute cut-offs but mostly single-thread. During chute cut-offs the water and bed levels upstream of

  7. Savannah River Ecology Laboratory. Annual technical progress report of ecological research

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.H.

    1996-07-31

    The Savannah River Ecology Laboratory (SREL) is a research unit of the University of Georgia (UGA). The overall mission of the Laboratory is to acquire and communicate knowledge of ecological processes and principles. SREL conducts basic and applied ecological research, as well as education and outreach programs, under a contract with the U.S. Department of Energy (DOE) at the Savannah River Site (SRS) near Aiken, South Carolina. Significant accomplishments were made during the past year in the areas of research, education and service. The Laboratory`s research mission was fulfilled with the publication of two books and 143 journal articles and book chapters by faculty, technical and students, and visiting scientists. An additional three books and about 80 journal articles currently are in press. Faculty, technician and students presented 193 lectures, scientific presentations, and posters to colleges and universities, including minority institutions. Dr. J Vaun McArthur organized and conducted the Third Annual SREL Symposium on the Environment: New Concepts in Strewn Ecology: An Integrative Approach. Dr. Michael Newman conducted a 5-day course titled Quantitative Methods in Ecotoxicology, and Dr. Brian Teppen of The Advanced Analytical Center for Environmental Sciences (AACES) taught a 3-day short course titled Introduction to Molecular Modeling of Environmental Systems. Dr. I. Lehr Brisbin co-hosted a meeting of the Crocodile Special Interest Group. Dr. Rebecca Sharitz attended four symposia in Japan during May and June 1996 and conducted meetings of the Executive Committee and Board of the International Association for Ecology (ENTECOL).

  8. Destructive Testing of an ES-3100 Shipping Container at the Savannah River National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Loftin, B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Abramczyk, G. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-06-09

    Destructive testing of an ES-3100 Shipping Container was completed by the Packaging Technology and Pressurized Systems organization within the Savannah River National Laboratory in order to qualify the ES-3100 as a candidate storage and transport package for applications at various facilities at the Savannah River Site. The testing consisted of the detonation of three explosive charges at separate locations on a single ES-3100. The locations for the placement were chosen based the design of the ES-3100 as well as the most likely places for the package to incur damage as a result of the detonation. The testing was completed at an offsite location, which raised challenges as well as allowed for development of new partnerships for this testing and for potential future testing. The results of the testing, the methods used to complete the testing, and similar, potential future work will be discussed.

  9. Climate change impacts on Chalk groundwater resources in eastern England

    Science.gov (United States)

    Hiscock, K.; Sandhu, C.; Conway, D.

    2004-05-01

    Climate change is expected to cause higher summer temperatures, less summer rainfall and more evapotranspiration in eastern England during this century, thereby increasing the stress on the underlying Chalk aquifer. This study, funded by the Tyndall Centre for Climate Change Research, investigates how future scenarios of climate change will influence groundwater availability in this major regional aquifer in terms of groundwater levels and river baseflow quantities. To examine these scenarios, a two-layer regional groundwater model was constructed with Visual MODFLOW for the Wensum and Nar river catchments in northern East Anglia. The UKCIP02 database for the `2020s High' and `2050s High and Low' gas emission scenarios was used to define selected future climate conditions. Historic recharge (1981-90) to the model is calculated separately, using the FAO approved method incorporating dominant land cover (crop type) and soil moisture content. Future recharge to the model is estimated by perturbing historic rainfall and evapotranspiration with scaling factors relating average monthly simulated future and baseline (1961-90) meteorological parameters. The model results predict an overall decrease in recharge for all three scenarios, with a maximum decrease in October of 62% and 91%, for both the 2020s High and 2050s High scenarios, respectively. The future drier summer periods are likely to cause a delay in the onset of recharge by a month, due to a corresponding overall increase in the evapotranspiration for all scenarios. Faced with these conditions, water companies are planning for less reliable groundwater resources within an overall risk-based approach to managing future water supply and demand.

  10. Savannah River Ecology Laboratory. Annual technical progress report of ecological research

    International Nuclear Information System (INIS)

    The Savannah River Ecology Laboratory (SREL) is a research unit of the University of Georgia (UGA). The overall mission of the Laboratory is to acquire and communicate knowledge of ecological processes and principles. SREL conducts basic and applied ecological research, as well as education and outreach programs, under a contract with the U.S. Department of Energy (DOE) at the Savannah River Site (SRS) near Aiken, South Carolina. Significant accomplishments were made during the past year in the areas of research, education and service. The Laboratory's research mission was fulfilled with the publication of two books and 143 journal articles and book chapters by faculty, technical and students, and visiting scientists. An additional three books and about 80 journal articles currently are in press. Faculty, technician and students presented 193 lectures, scientific presentations, and posters to colleges and universities, including minority institutions. Dr. J Vaun McArthur organized and conducted the Third Annual SREL Symposium on the Environment: New Concepts in Strewn Ecology: An Integrative Approach. Dr. Michael Newman conducted a 5-day course titled Quantitative Methods in Ecotoxicology, and Dr. Brian Teppen of The Advanced Analytical Center for Environmental Sciences (AACES) taught a 3-day short course titled Introduction to Molecular Modeling of Environmental Systems. Dr. I. Lehr Brisbin co-hosted a meeting of the Crocodile Special Interest Group. Dr. Rebecca Sharitz attended four symposia in Japan during May and June 1996 and conducted meetings of the Executive Committee and Board of the International Association for Ecology (ENTECOL)

  11. Savannah River Ecology Laboratory. Annual technical progress report of ecological research, period ending July 31, 1994

    Energy Technology Data Exchange (ETDEWEB)

    1994-07-31

    The Savannah River Ecology Laboratory (SREL) is a research unit of the University of Georgia (UGA) that is managed in conjunction with the University`s Institute of Ecology. The laboratory`s overall mission is to acquire and communicate knowledge of ecological processes and principles. SREL conducts basic and applied ecological research, as well as education and outreach programs, under an M&O contract with the US Department of Energy at the Savannah River Site. Significant accomplishments were made during the year ending July 31, 1994 in the areas of research, education and service. Reviewed in this document are research projects in the following areas: Environmental Operations Support (impacted wetlands, streams, trace organics, radioecology, database synthesis, wild life studies, zooplankton, safety and quality assurance); wood stork foraging and breeding ecology; defence waste processing facility; environmental risk assessment (endangered species, fish, ash basin studies); ecosystem alteration by chemical pollutants; wetlands systems; biodiversity on the SRS; Environmental toxicology; environmental outreach and education; Par Pond drawdown studies in wildlife and fish and metals; theoretical ecology; DOE-SR National Environmental Research Park; wildlife studies. Summaries of educational programs and publications are also give.

  12. CONTROL TESTING OF THE UK NATIONAL NUCLEAR LABORATORY'S RADBALL TECHNOLOGY AT SAVANNAH RIVER NATIONAL LABORATORY

    Energy Technology Data Exchange (ETDEWEB)

    Farfan, E.

    2009-11-23

    The UK National Nuclear Laboratory (NNL) has developed a remote, non-electrical, radiation-mapping device known as RadBall (patent pending), which offers a means to locate and quantify radiation hazards and sources within contaminated areas of the nuclear industry. To date, the RadBall has been deployed in a number of technology trials in nuclear waste reprocessing plants at Sellafield in the UK. The trials have demonstrated the successful ability of the RadBall technology to be deployed and retrieved from active areas. The positive results from these initial deployment trials and the anticipated future potential of RadBall have led to the NNL partnering with the Savannah River National Laboratory (SRNL) to further underpin and strengthen the technical performance of the technology. RadBall consists of a colander-like outer shell that houses a radiation-sensitive polymer sphere. It has no power requirements and can be positioned in tight or hard-to reach places. The outer shell works to collimate radiation sources and those areas of the polymer sphere that are exposed react, becoming increasingly less transparent, in proportion to the absorbed dose. The polymer sphere is imaged in an optical-CT scanner which produces a high resolution 3D map of optical attenuation coefficients. Subsequent analysis of the optical attenuation maps provides information on the spatial distribution and strength of the sources in a given area forming a 3D characterization of the area of interest. This study completed at SRNL addresses key aspects of the testing of the RadBall technology. The first set of tests was performed at Savannah River Nuclear Solutions Health Physics Instrument Calibration Laboratory (HPICL) using various gamma-ray sources and an x-ray machine with known radiological characteristics. The objective of these preliminary tests was to identify the optimal dose and collimator thickness. The second set of tests involved a highly contaminated hot cell. The objective of

  13. Laboratory Assessment of Potential Impacts to Dungeness Crabs from Disposal of Dredged Material from the Columbia River

    Energy Technology Data Exchange (ETDEWEB)

    Vavrinec, John; Pearson, Walter H.; Kohn, Nancy P.; Skalski, J. R.; Lee, Cheegwan; Hall, Kathleen D.; Romano, Brett A.; Miller, Martin C.; Khangaonkar, Tarang P.

    2007-05-07

    Dredging of the Columbia River navigation channel has raised concerns about dredging-related impacts on Dungeness crabs (Cancer magister) in the estuary, mouth of the estuary, and nearshore ocean areas adjacent to the Columbia River. The Portland District, U.S. Army Corps of Engineers engaged the Marine Sciences Laboratory (MSL) of the U.S. Department of Energy’s Pacific Northwest National Laboratory to review the state of knowledge and conduct studies concerning impacts on Dungeness crabs resulting from disposal during the Columbia River Channel Improvement Project and annual maintenance dredging in the mouth of the Columbia River. The present study concerns potential effects on Dungeness crabs from dredged material disposal specific to the mouth of the Columbia River.

  14. Kolmanda aastatuhande piraadid / kommenteerinud Peter Chalk ja Gordan Van Hook

    Index Scriptorium Estoniae

    2009-01-01

    Piraatlusest Somaalia piirkonnas ja rahvusvahelistest dokumentidest piraatluse vastu võitlemiseks 21. sajandil. Kommenteerivad uurimiskeskuse RAND Corporation vanempoliitanalüütik Peter Chalk ja transpordikompanii Maersk Line innovatsiooni ja arenduse vanemdirektor Gordan Van Hook

  15. Mapping SOC in a river catchment by integrating laboratory spectra wavelength with remote sensing spectra

    DEFF Research Database (Denmark)

    Peng, Yi; Xiong, Xiong; Knadel, Maria;

    There is potential to use soil ·-proximal and remote sensing derived spectra concomitantly to develop soil organic carbon (SOC) models. Yet mixing spectral data from different sources and technologies to improve soil models is still in its infancy. The objective of this study was to incorporate...... soil spectral features indicative of SOC from laboratory visible near-infrared reflectance (vis-NlR) spectra and incorporate them with remote sensing (RS) images to improve predictions of top SOC in the Skjem river catchment, Denmark. The secondary objective was to improve prediction results by...

  16. The invertebrate ecology of the Chalk aquifer in England (UK)

    Science.gov (United States)

    Maurice, L.; Robertson, A. R.; White, D.; Knight, L.; Johns, T.; Edwards, F.; Arietti, M.; Sorensen, J. P. R.; Weitowitz, D.; Marchant, B. P.; Bloomfield, J. P.

    2016-03-01

    The Chalk is an important water supply aquifer, yet ecosystems within it remain poorly understood. Boreholes (198) in seven areas of England (UK) were sampled to determine the importance of the Chalk aquifer as a habitat, and to improve understanding of how species are distributed. Stygobitic macro-invertebrates were remarkably common, and were recorded in 67 % of boreholes in unconcealed Chalk, although they were not recorded in Chalk that is concealed by low-permeability strata and thus likely to be confined. Most species were found in shallow boreholes (50 m) water tables, indicating that the habitat is vertically extensive. Stygobites were present in more boreholes in southern England than northern England (77 % compared to 38 %). Only two species were found in northern England compared to six in southern England, but overall seven of the eight stygobitic macro-invertebrate species found in England were detected in the Chalk. Two species are common in southern England, but absent from northern England despite the presence of a continuous habitat prior to the Devensian glaciation. This suggests that either they did not survive glaciations in the north where glaciers were more extensive, or dispersal rates are slow and they have never colonised northern England. Subsurface ecosystems comprising aquatic macro-invertebrates and meiofauna, as well as the microbial organisms they interact with, are likely to be widespread in the Chalk aquifer. They represent an important contribution to biodiversity, and may influence biogeochemical cycles and provide other ecosystem services.

  17. Transient groundwater chemistry near a river: Effects on U(VI) transport in laboratory column experiments

    Science.gov (United States)

    Yin, Jun; Haggerty, Roy; Stoliker, Deborah L.; Kent, Douglas B.; Istok, Jonathan D.; Greskowiak, Janek; Zachara, John M.

    2011-01-01

    In the 300 Area of a U(VI)-contaminated aquifer at Hanford, Washington, USA, inorganic carbon and major cations, which have large impacts on U(VI) transport, change on an hourly and seasonal basis near the Columbia River. Batch and column experiments were conducted to investigate the factors controlling U(VI) adsorption/desorption by changing chemical conditions over time. Low alkalinity and low Ca concentrations (Columbia River water) enhanced adsorption and reduced aqueous concentrations. Conversely, high alkalinity and high Ca concentrations (Hanford groundwater) reduced adsorption and increased aqueous concentrations of U(VI). An equilibrium surface complexation model calibrated using laboratory batch experiments accounted for the decrease in U(VI) adsorption observed with increasing (bi)carbonate concentrations and other aqueous chemical conditions. In the column experiment, alternating pulses of river and groundwater caused swings in aqueous U(VI) concentration. A multispecies multirate surface complexation reactive transport model simulated most of the major U(VI) changes in two column experiments. The modeling results also indicated that U(VI) transport in the studied sediment could be simulated by using a single kinetic rate without loss of accuracy in the simulations. Moreover, the capability of the model to predict U(VI) transport in Hanford groundwater under transient chemical conditions depends significantly on the knowledge of real-time change of local groundwater chemistry.

  18. Analysis of the spatiotemporal planform dynamics of braided rivers: a novel laboratory investigation

    Science.gov (United States)

    Redolfi, Marco; Bertoldi, Walter; Tubino, Marco

    2016-04-01

    Braided rivers are highly dynamic, labile environments which experience significant morphological changes even during moderate flow events. Recent remote sensing techniques enable to monitor the river morphology with great detail. However, capturing the rapid morphological changes of a large river with sufficient temporal and spatial resolution is still very challenging. As a consequence, quantitative analysis of the braided channel dynamics is often limited to local processes (e.g. a single bifurcation or confluence) and short time periods (e.g. a single flood). This work aims at providing quantitative, statistical description of the channel network dynamics in a braided network at larger spatial and temporal scales, namely the reach scale and the multiple flood scale. This can be achieved using a new technique based on time lapse imagery that we recently developed at the University of Trento. This technique provides high frequency, two dimensional maps of the bed load transport in a large laboratory model, thus allowing to capture the spatiotemporal variability of the transport processes with unprecedented detail. We performed a set of laboratory experiments in a 23 m long, 3 m wide flume, sand bed load flume, where self-formed braided networks can be reproduced. We run several experiments with different discharges and channel widths, lasting for a long time (from 20 to 65 hours) to enable a robust statistical description of the equilibrium morphodynamics. High-resolution pictures were taken at 1 min interval from two SLR cameras, then rectified and merged in order to cover a 7 m long reach. We processed a large number of images to obtain maps of bed load transport, and we developed an algorithm to automatically identifies active (i.e. transporting) channels, bifurcations and confluences. The statistical analysis we performed includes two dimensional correlations, spatial and temporal scales, channel migration rate, avulsion frequency, bank erosion rate. This

  19. Savannah River Ecology Laboratory. Annual technical progress report of ecological research, period ending July 31, 1994

    International Nuclear Information System (INIS)

    The Savannah River Ecology Laboratory (SREL) is a research unit of the University of Georgia (UGA) that is managed in conjunction with the University's Institute of Ecology. The laboratory's overall mission is to acquire and communicate knowledge of ecological processes and principles. SREL conducts basic and applied ecological research, as well as education and outreach programs, under an M ampersand O contract with the US Department of Energy at the Savannah River Site. Significant accomplishments were made during the year ending July 31, 1994 in the areas of research, education and service. Reviewed in this document are research projects in the following areas: Environmental Operations Support (impacted wetlands, streams, trace organics, radioecology, database synthesis, wild life studies, zooplankton, safety and quality assurance); wood stork foraging and breeding ecology; defence waste processing facility; environmental risk assessment (endangered species, fish, ash basin studies); ecosystem alteration by chemical pollutants; wetlands systems; biodiversity on the SRS; Environmental toxicology; environmental outreach and education; Par Pond drawdown studies in wildlife and fish and metals; theoretical ecology; DOE-SR National Environmental Research Park; wildlife studies. Summaries of educational programs and publications are also give

  20. The balanced scorecard advantage: Driving strategic change into Canada's nuclear laboratory site operations

    International Nuclear Information System (INIS)

    The challenges presented by the size, diversity, complexity and history of the Facilities and Nuclear Operations (FNO) Group at AECL's Chalk River Laboratories (CRL) required a change to the traditional management approach. As a result, a strategy was adopted that focused on integrating contemporary business practices such as process mapping, activity based management and use of the Balanced Scorecard methodology into the operational culture at CRL. In addition, revitalization of the performance management methods process was undertaken to provide a tool for assessment of business and individual performance. performance. (author)

  1. Understanding heterogeneity in UK Chalk catchments and its influence on groundwater flooding

    Science.gov (United States)

    Peach, D. W.; Vounaki, T.; Jackson, C. R.; Hughes, A. G.; Wheater, H. S.

    2008-12-01

    The numerical simulation of groundwater flooding is increasingly necessary as this problem is gaining recognition from government and regulators and climate change may bring more extreme events. The Natural Environment Research Council of the UK is funding the British Geological Survey, Imperial College, and the Centre for Ecology and Hydrology to examine the problem of groundwater flooding in the Cretaceous Chalk of Berkshire, 50 kilometres west of London. Typically regional resource issues can be examined using traditional groundwater models that do not consider in detail the influence of flow in the unsaturated zone, but the delays in recharge transmission through this zone to the water table may be very significant in terms of flood timing and prediction. The position of ground elevation relative to water table is clearly important but not often considered in groundwater resource modelling. Groundwater level and stream (and flood) flow responses are important data that may be hard to gather from typical groundwater monitoring systems. These problems have been examined in a Chalk catchment in Berkshire where good records of the 2000-1 and 2003 flooding events have been collected, including flooded extent, rainfall, groundwater levels, river and spring flows. From this analysis, it appears that two groundwater mounds develop in the upper part of the Pang and Lambourn catchments. These mounds intersect dry valleys, which flowed for several months, the consequent flooding causing considerably disruption. Modelling of these events is providing new insight into the heterogeneity of Chalk transmissivity and storage parameters, enhanced knowledge of its dual permeability and porosity and demonstrating the importance of understanding the post-depositional hydrogeological history of the aquifer.

  2. Magnetic field measurements on the Chalk River superconducting cyclotron

    International Nuclear Information System (INIS)

    Midplane magnetic fields have been measured for the modified flutter pole geometry of the cyclotron magnet at forty-eight excitations with mean inductions spanning the range two to five tesla. Midplane fringing fields have been measured both through the cryostat and beyond the yoke at selected excitations. Measurements of yoke temperature effects and hysteresis are also described

  3. Small karstic Dobra River (Croatia) suggested as natural laboratory for impactite research

    Science.gov (United States)

    Frančišković-Bilinski, Stanislav; Bilinski, Halka; Sikder, Arif M.

    2016-04-01

    An unexpected anomaly of magnetic susceptibility (MS) was observed in stream sediments of the upper course of the karstic Dobra River (Croatia). Preliminary results pointed to a possible impactite, formed by a shock event caused by a meteorite impact or by volcanic processes [1]. In addition to geophysical experiments, petrological and geochemical studies are reported [2, 3]. The multidisciplinary work for identification and confirmation of impact structure is still in progress. Results will be presented and the difficulties due to weathering and transport processes will be discussed and compared with recent literature [4, 5]. In reported results numerous evidences exist, which are in support of impact origin, such as vesicular glass with quench texture, ballen textures in the lechatelierite, presence of Troilite, etc. We suggest that the Dobra River from its source to the abyss in Ogulin (Upper Dobra) is a possible natural laboratory for studying processes of mixing between impactite material and fluvial sediments within a small area, including spherules exposed to water and in the overbank sediments. Especially the introduction of isotope studies in this research and enlargement of multinational team of experts are suggested. Literature: [1] Franči\\vsković-Bilinski, S., Bilinski, H., Scholger, R., Tomašić, N., Maldini, K. (2014): Magnetic spherules in sediments of the sinking karstic Dobra River (Croatia). Journal of soils and sediments 14(3), 600-614. [2] Franči\\vsković-Bilinski, S., Sikder, A.M., Bilinski, H., Castano, C.E., Garman, G.C. (2015): Traces of meteorite impact in the sediments of karstic Dobra River (Croatia). 15th International multidisciplinary scientific geoconference SGEM 2015 Conference proceedings, Vol. 1, 507-514. [3] Sikder, A.M., Franči\\vsković-Bilinski, S., Bilinski, H., Castano, C.E., Clifford, D.M., Turner, J.B., Garman, G.C. (2015): Petrographic analysis of the magnetic spherules from the sediments of karastic Dobra River

  4. RadBallTM Technology Testing in the Savannah River Site's Health Physics Instrument Calibration Laboratory

    International Nuclear Information System (INIS)

    The UK's National Nuclear Laboratory (NNL) has developed a radiation-mapping device that can locate and quantify radioactive hazards within contaminated areas of the nuclear industry. The device, known as RadBallTM, consists of a colander-like outer collimator that houses a radiation-sensitive polymer sphere. The collimator has over two hundred small holes; thus, specific areas of the polymer sphere are exposed to radiation becoming increasingly more opaque in proportion to the absorbed dose. The polymer sphere is imaged in an optical-CT scanner that produces a high resolution 3D map of optical attenuation coefficients. Subsequent analysis of the optical attenuation data provides information on the spatial distribution of sources in a given area forming a 3D characterization of the area of interest. The RadBallTM technology has been deployed in a number of technology trials in nuclear waste reprocessing plants at Sellafield in the UK and facilities of the Savannah River National Laboratory (SRNL). This paper summarizes the tests completed at SRNL Health Physics Instrument Calibration Laboratory (HPICL).

  5. RadBallTM Technology Testing in the Savannah River Site's Health Physics Instrument Calibration Laboratory

    Science.gov (United States)

    Farfán, Eduardo B.; Foley, Trevor Q.; Jannik, G. Timothy; Harpring, Larry J.; Gordon, John R.; Blessing, Ronald; Rusty Coleman, J.; Holmes, Christopher J.; Oldham, Mark; Adamovics, John; Stanley, Steven J.

    2010-11-01

    The UK's National Nuclear Laboratory (NNL) has developed a radiation-mapping device that can locate and quantify radioactive hazards within contaminated areas of the nuclear industry. The device, known as RadBallTM, consists of a colander-like outer collimator that houses a radiation-sensitive polymer sphere. The collimator has over two hundred small holes; thus, specific areas of the polymer sphere are exposed to radiation becoming increasingly more opaque in proportion to the absorbed dose. The polymer sphere is imaged in an optical-CT scanner that produces a high resolution 3D map of optical attenuation coefficients. Subsequent analysis of the optical attenuation data provides information on the spatial distribution of sources in a given area forming a 3D characterization of the area of interest. The RadBallTM technology has been deployed in a number of technology trials in nuclear waste reprocessing plants at Sellafield in the UK and facilities of the Savannah River National Laboratory (SRNL). This paper summarizes the tests completed at SRNL Health Physics Instrument Calibration Laboratory (HPICL).

  6. RadBall Technology Testing in the Savannah River Site's Health Physics Instrument Calibration Laboratory.

    Science.gov (United States)

    Farfán, Eduardo B; Foley, Trevor Q; Jannik, G Timothy; Harpring, Larry J; Gordon, John R; Blessing, Ronald; Coleman, J Rusty; Holmes, Christopher J; Oldham, Mark; Adamovics, John; Stanley, Steven J

    2010-01-01

    The United Kingdom's National Nuclear Laboratory (NNL) has developed a radiation-mapping device that can locate and quantify radioactive hazards within contaminated areas of the nuclear industry. The device, known as RadBall(™), consists of a colander-like outer collimator that houses a radiation-sensitive polymer sphere. The collimator has over two hundred small holes; thus, specific areas of the polymer sphere are exposed to radiation becoming increasingly more opaque in proportion to the absorbed dose. The polymer sphere is imaged in an optical-CT scanner that produces a high resolution 3D map of optical attenuation coefficients. Subsequent analysis of the optical attenuation data provides information on the spatial distribution of sources in a given area forming a 3D characterization of the area of interest. The RadBall(™) technology has been deployed in a number of technology trials in nuclear waste reprocessing plants at Sellafield in the United Kingdom and facilities of the Savannah River National Laboratory (SRNL). This paper summarizes the tests completed at SRNL Health Physics Instrument Calibration Laboratory (HPICL). PMID:21617738

  7. Self-formed meandering river created in the laboratory using an upstream migrating boundary

    Science.gov (United States)

    van Dijk, W. M.; van de Lageweg, W. I.; Kleinhans, M. G.

    2010-12-01

    Braided rivers are relatively easily formed in the laboratory, whereas self-formed meandering rivers in the lab have proven very difficult to form, indicating a lack of understanding of the necessary and sufficient conditions for meandering. Our objective is to create self-formed dynamic meandering rivers and floodplains in a laboratory. Early experiments attempted to initiate meandering with upstream inflow at a fixed angle different from the general flow direction. The resulting bends were fixed at one position, which is not the dynamic meandering observed in nature. Another important condition for meandering is to have banks stronger than the non-cohesive bed sediment, which has been attained by growing vegetation. Furthermore, finer or light-weight sediment has been used to let chute channels fill up where otherwise multi-thread channels would have evolved, which is braiding. Yet the fixed-angle inflow kept meander migration and channel belt width and complexity limited. We accomplished dynamic meandering in the laboratory by using an upstream migrating boundary, which simulates a meander migrating into the flume. Our experiments were conducted in a circulated flume of 11x6 meter, with a constant discharge and sediment feed consisting of a sediment mixture ranging from silt to fine gravel (Kleinhans et al., 2010, this conference). The downstream boundary is a lake into which the river built a branched fan delta (Van de Lageweg et al., 2010, this conference). The morphology was recorded by high-resolution (0.5 mm) line-laser scanning and digital Single Lens Reflex (SLR) camera used for channel-floodplain segmentation and particle size estimation, at an interval of 8 hours. Furthermore a large number of smaller-scale auxiliary experiments were conducted to explore meandering tendency in a large range of parameters. Initial alternate ‘forced’ bars were formed at fixed positions with low sinuosity when the upstream boundary was at one fixed position. Migration

  8. What are the governing processes during low-flows in a chalk catchment?

    Science.gov (United States)

    Lubega Musuuza, Jude; Coxon, Gemma; Hutton, Chris; Howden, Nicholas; Woods, Ross; Freer, Jim; Wagener, Thorsten

    2016-04-01

    Low flows are important because they lead to the prioritisation of different consumptive water usages, imposition of restrictions and bans, raising of water tariffs and higher production costs to industry. The partitioning of precipitation into evaporation, storage and runoff depends on the local variability in meteorological variables and site-specific characteristics e.g., topography, soils and vegetation. The response of chalk catchments to meteorological forcing especially precipitation is of particular interest because of the preferential flow through the weathered formation. This makes the observed stream discharge groundwater-dominated and hence, out of phase with precipitation. One relevant question is how sensitive the low flow characteristics of such a chalk catchment is to changes in climate and land use. It is thus important to understand all the factors that control low stream discharge periods. In this study we present the results from numerical sensitivity analysis experiments performed with a detailed physically-based model on the Kennet, a sub-catchment of the River Thames, in the UK during the historical drought years of the 1970's.

  9. Burial diagenesis of deep sea chalk as reflected in Biot's coefficient

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke; Alam, Mohammad Monzurul

    2013-01-01

    Burial diagenesis of chalk has been widely studied, but little agreement has been reached on by which mechanism porosity declines, and on how to calculate the deforming stress in the most informative way. Data from Ocean Drilling Program show that calcareous ooze transforms to chalk and chalk to ...

  10. Influence of effective stress coefficient on mechanical failure of chalk

    DEFF Research Database (Denmark)

    Alam, Mohammad Monzurul; Fabricius, Ida Lykke; Hjuler, M.L.;

    2012-01-01

    The Effective stress coefficient is a measure of how chalk grains are connected with each other. The stiffness of chalk may decrease if the amount of contact cements between the grains decreases, which may lead to an increase of the effective stress coefficient. We performed CO2 injection in chalk......, as this process could affect the grain contact cement. If this happens, the effective stress at the grain contacts in a reservoir will change according to the effective stress principle of Biot. In a p′-q space for failure analysis, we observed that a higher effective stress coefficient reduces the...... elastic region and vice versa. However, as the effective stress working on the rock decreases with increased effective stress coefficient, the reduction of elastic region will have less effect on pore collapse strength if we consider the change in the effective stress coefficient. This finding will help...

  11. Chemical and Mechanical processes during burial diagenesis of chalk

    DEFF Research Database (Denmark)

    Borre, Mai Kirstine; Lind, Ida

    1998-01-01

    equal or larger influence on the textural development. In the chalk interval below, compaction is not the only porosity reducing agent but it has a larger influence on texture than concurrent recrystallization. Below 850 m grain-bridging cementation becomes important resulting in a lithified limestone......Burial diagenesis of chalk is a combination of mechanical compaction and chemical recrystallization as well as cementation. We have predicted the characteristic trends in specific surface resulting from these processes. The specific surface is normally measured by nitrogen adsorption but is here...... the Pacific, where a > 1 km thick package of chalk facies sediments accumulated from the Cretaceous to the present. In the upper 200-300 m the sediment is unconsolidated carbonate ooze, throughout this depth interval compaction is the principal porosity reducing agent, but recrystallization has an...

  12. Managing extremes in groundwater-dominated catchments: the Chalk of SE England (Invited)

    Science.gov (United States)

    Wheater, H. S.

    2009-12-01

    The Chalk aquifers of Southern and Eastern England are a dominant local and regional water resource, and rivers located on the Chalk outcrop have a characteristic behaviour and support valuable and protected aquatic ecosystems. In these catchments, typically less than 2% of rainfall is translated into stormflow response. Infiltration occurs into an unsaturated zone that varies in depth from zero at the stream to 100m at the interfluve. Seasonal groundwater recharge is translated into a seasonal river hydrograph, and the length of flowing river expands and contracts seasonally - so-called ‘bourne’ behaviour. Groundwater catchment areas also vary temporally, and stream-aquifer interactions can be complex. Extensive and long duration flooding in 2000/2001 highlighted the vulnerability of these systems to extremes of long duration rainfall (weeks and months). Source areas for runoff expand into dry valleys, springs break out in ‘new’ locations and given the normally low %runoff, highly non-linear flow response occurs. Conversely, droughts are also of major concern, particularly given scenarios of climate change for SE England. Water quality issues are also important, particularly nutrient pollution. These management concerns have focussed attention on the need for improved understanding, and for appropriate modelling tools for flood risk assessment and drought and water quality management. The paper addresses recent research into the historic behaviour of these systems under extremes, the relative roles of fracture and porous matrix flow in the unsaturated zone under extremes, and the nature of stream-aquifer interactions, including detailed experimental studies. Challenges for modelling are identified; for groundwater flooding conventional flood design approaches are inadequate, but groundwater models lack appropriate topographic constraints and the required spatial and temporal resolution; for drought, recharge estimation and diffuse pollution, better

  13. Intensive archaeological survey of the proposed Savannah River Ecology Laboratory Conference Center and Educational Facility, Savannah River Site, Aiken County, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Stephenson, K.; Crass, D.C.; Sassaman, K.E.

    1993-02-01

    Documented in this report are the methods and results of an intensive archaeological survey for the proposed University of Georgia Savannah River Ecology Laboratory (SREL) Conference Center and Educational Facility on the DOE Savannah River Site (SRS). Archaeological investigations conducted by the Savannah River Archaeological Research Program (SRARP) on the 70-acre project area and associated rights-of-way consisted of subsurface testing at two previously recorded sites and the discovery of one previously unrecorded site. The results show that 2 sites contain archaeological remains that may yield significant information about human occupations in the Aiken Plateau and are therefore considered eligible for nomination to the National Register of Historic Places. Adverse impacts to these sites can be mitigated through avoidance.

  14. Sediment transport and siltation of brown trout (Salmo trutta L.) spawning gravels in chalk streams

    Science.gov (United States)

    Acornley, R. M.; Sear, D. A.

    1999-02-01

    Deposition rates of fine sediment into brown trout spawning gravels were measured at monthly intervals for a period of one year in a small channel of the River Test, Hampshire. Data were also collected on stream discharge, water depth, flow velocity and suspended sediment concentrations. Deposition rates followed a seasonal pattern and were maximal during periods of high discharge in the late winter/early spring when suspended sediment concentrations were high. The material deposited in the spawning gravels included silts and fine sands (<250 m) that were transported in suspension and coarser fragments of low density tufa-like material that were transported as bed load. The ecological implications of fine sediment deposition for salmonid egg survival in chalk streams are considered.

  15. Chalk porosity and sonic velocity versus burial depth

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke; Gommesen, Lars; Krogsbøll, Anette Susanne;

    2008-01-01

    Seventy chalk samples from four formations in the overpressured Danish central North Sea have been analyzed to investigate how correlations of porosity and sonic velocity with burial depth are affected by varying mineralogy, fluid pressure, and early introduction of petroleum. The results show th...

  16. Nano sized clay detected on chalk particle surfaces

    DEFF Research Database (Denmark)

    Skovbjerg, Lone; Hassenkam, Tue; Makovicky, Emil;

    2012-01-01

    that in calcite saturated water, both the polar and the nonpolar functional groups adhere to the nano sized clay particles but not to calcite. This is fundamentally important information for the development of conceptual and chemical models to explain wettability alterations in chalk reservoirs...

  17. Specific surface as a measure of burial diagenesis of chalk

    DEFF Research Database (Denmark)

    Borre, Mai Kirstine; Lind, Ida; Mortensen, Jeanette

    ODP Leg 130, Site 807, in the western equatorial Pacific, penetrates a sequence of pelagic carbonate ooze, chalk and limestone. Compaction, recrystallisation and cementation of the carbonate matrix are diagenetic processes expected to be taking place more or less simultaneously. In order to assess...

  18. Quantitative 1D saturation profiles on chalk by NMR

    DEFF Research Database (Denmark)

    Olsen, Dan; Topp, Simon; Stensgaard, Anders;

    1996-01-01

    Quantitative one-dimensional saturation profiles showing the distribution of water and oil in chalk core samples are calculated from NMR measurements utilizing a 1D CSI spectroscopy pulse sequence. Saturation profiles may be acquired under conditions of fluid flow through the sample. Results reveal...

  19. Groundwater conversion areas in chalk in the southern Frankish Alps

    International Nuclear Information System (INIS)

    In order to collect hydro-geological data, chalk water marking was done and/or interpreted, water balances were produced, the contents tritium, oxygen 18, calcium, magnesium and the groundwater temperatures and electrolytic conductivity of the groundwater were examined and the dry weather drainage of individual sources was analysed. (orig./PW)

  20. Savannah River Ecology Laboratory, Annual Technical Progress Report of Ecological Research, June 30, 2002

    International Nuclear Information System (INIS)

    The Savannah River Ecology Laboratory (SREL) is a research unit of The University of Georgia (UGA) and has been conducting ecological research on the Savannah River Site (SRS) near Aiken, South Carolina for 50 years. The overall mission of the Laboratory is to acquire and communicate knowledge of ecological processes and principles. SREL conducts fundamental and applied ecological research, as well as education and outreach programs, under a Cooperative Agreement with the U.S. Department of Energy (DOE). The Laboratory's research mission during the 2002 fiscal year was fulfilled with the publication of 76 journal articles and book chapters by faculty, technical staff, students, and visiting scientists. An additional 50 journal articles have been submitted or are in press. Other noteworthy events took place as faculty members, staff, and graduate students received awards. These are described in the section titled Special Accomplishments of Faculty, Staff, Students, and Administration on page 51. Notable scientific accomplishments include work conducted on contaminant transport, stable isotopes, sandhills ecology, and phytoremediation: (1) A collaborative study between Dr. Tom Hinton at SREL and scientists at SRTC demonstrated the feasibility of using illite clay to sequester 137Cs in sediments along the P and R reactor cooling canal system, where approximately 3, 000 acres of land are contaminated. Overall, the study showed significant decreases in cesium concentrations and bioavailability following the addition of illite with no sign of harm to the ecosystem. While the cesium remains sequestered from the biosphere, its radioactivity decays and the process progresses from contaminant immobilization to remediation. (2) SREL's stable isotope laboratory is now fully functional. Stable isotope distributions in nature can provide important insights into many historical and current environmental processes. Dr. Christopher Romanek is leading SREL's research in this area

  1. Savannah River Ecology Laboratory, Annual Technical Progress Report of Ecological Research, June 30, 2002

    Energy Technology Data Exchange (ETDEWEB)

    Paul M. Bertsch, (Director)

    2002-06-30

    The Savannah River Ecology Laboratory (SREL) is a research unit of The University of Georgia (UGA) and has been conducting ecological research on the Savannah River Site (SRS) near Aiken, South Carolina for 50 years. The overall mission of the Laboratory is to acquire and communicate knowledge of ecological processes and principles. SREL conducts fundamental and applied ecological research, as well as education and outreach programs, under a Cooperative Agreement with the U.S. Department of Energy (DOE). The Laboratory's research mission during the 2002 fiscal year was fulfilled with the publication of 76 journal articles and book chapters by faculty, technical staff, students, and visiting scientists. An additional 50 journal articles have been submitted or are in press. Other noteworthy events took place as faculty members, staff, and graduate students received awards. These are described in the section titled Special Accomplishments of Faculty, Staff, Students, and Administration on page 51. Notable scientific accomplishments include work conducted on contaminant transport, stable isotopes, sandhills ecology, and phytoremediation: (1) A collaborative study between Dr. Tom Hinton at SREL and scientists at SRTC demonstrated the feasibility of using illite clay to sequester 137Cs in sediments along the P and R reactor cooling canal system, where approximately 3,000 acres of land are contaminated. Overall, the study showed significant decreases in cesium concentrations and bioavailability following the addition of illite with no sign of harm to the ecosystem. While the cesium remains sequestered from the biosphere, its radioactivity decays and the process progresses from contaminant immobilization to remediation. (2) SREL's stable isotope laboratory is now fully functional. Stable isotope distributions in nature can provide important insights into many historical and current environmental processes. Dr. Christopher Romanek is leading SREL's research

  2. Savannah River Laboratory environmental transport and effects research. Annual report, 1974

    International Nuclear Information System (INIS)

    The principal objective of environmental transport research at the Savannah River Laboratory (SRL) is to develop, apply, adapt, use, test, and verify models that predict the directions and magnitude of ecosystem processes. Since an ecosystem is understood to be a complex ecological unit composed of physical, chemical, and biotic components interacting in the cycling and transport of matter and the flow of energy, the understanding of ecosystem processes demands integrated study by scientists of differing disciplines. Data are included from studies on factors that affect the atmospheric transport and dispersion of radionuclides and chemical effluents; surface and groundwater transport of various pollutants following release to the soil surface or a flowing stream; the uptake and retention of tritium oxide by pine trees; calculations of the radiation dose commitment for human populations from 14C released by the nuclear industry; the effects of thermal effluents on aquatic organisms, including plankton productivity, the population dynamics of freshwater snails, and the growth and respiration rates of the sand-burrowing mayfly (Dolania americana). Data are included from a survey of seismic activity in South Carolina. (CH)

  3. Transmissivity of the Snake River Plain aquifer at the Idaho National Engineering Laboratory, Idaho

    International Nuclear Information System (INIS)

    Aquifer-test data of 183 single-well tests at 94 wells in the Snake River Plain aquifer were analyzed to estimate values of transmissivity. Estimates of transmissivity for individual wells range from 1.1 to 7.6 x 105 feet squared per day, nearly 6 orders of magnitude. These data were determined in a consistent manner and are useful for describing the distribution of transmissivity at the Idaho National Engineering Laboratory. The results of type-curve analysis of 37 tests at 26 wells were used to develop a regression relation between specific capacity and transmissivity. This relation, in turn, was used to analyze all specific-capacity data. Values of relative uncertainty for estimated values of transmissivity generally ranged from 0.1 order of magnitude for type-curve analysis to 0.5 order of magnitude for specific-capacity analysis with measured drawdown of less than 0.1 foot. 16 refs., 10 figs., 3 tabs

  4. Savannah River Ecology Laboratory Annual Technical Progress Report of Ecological Research, June 30, 2001

    Energy Technology Data Exchange (ETDEWEB)

    Bertsch, Paul M.; Janecek, Laura; Rosier, Brenda

    2001-06-30

    The Savannah River Ecology Laboratory (SREL) is a research unit of the University of Georgia (UGA) and has been conducting ecological research on the Savannah River Site (SRS) in South Carolina for 50 years. The overall mission of the Laboratory is to acquire and communicate knowledge of ecological processes and principles. SREL conducts fundamental and applied ecological research, as well as education and outreach programs, under a Cooperative Agreement with the U.S. Department of Energy (DOE) SRS near Aiken, South Carolina. The Laboratory's research mission during the 2001 fiscal year was fulfilled with the publication of one book and 83 journal articles and book chapters by faculty, technical staff, students, and visiting scientists. An additional 77 journal articles have been submitted or are in press. Other noteworthy events took place as faculty members and graduate students received awards. These are described in the section Special Accomplishments of Faculty, Staff, Students, and Administration on page 54. Notable scientific accomplishments include work conducted on contaminant transport, global reptile decline, phytoremediation, and radioecology. Dr. Domy Adriano authored the second edition of his book ''Trace Elements in Terrestrial Environments: Biogeochemistry, Bioavailability, and Risks of Metals'', which was recently published by Springer-Verlag. The book provides a comprehensive treatment of many important aspects of trace elements in the environment. The first edition of the book, published in 1986, has become a widely acclaimed and cited reference. International attention was focused on the problem of reptile species decline with the publication of an article on this topic in the journal ''Bioscience'' in August, 2000. The article's authors included Dr. Whit Gibbons and a number of other SREL herpetologists who researched the growing worldwide problem of decline of reptile species. Factors related

  5. Savannah River Ecology Laboratory, annual technical progress report of ecological research for the year ending June 30, 1998

    International Nuclear Information System (INIS)

    This report provides an overview of the research programs and program components carried out by the Savannah River Ecology Laboratory. Research focused on the following: advanced analytical and spectroscopic techniques for developing novel waste isolation and stabilization technologies as well as cost-effective remediation strategies; ecologically sound management of damaged and remediation of ecological systems; ecotoxicology, remediation, and risk assessment; radioecology, including dose assessments for plants and animals exposed to environmental radiation; and other research support programs

  6. Savannah River Ecology Laboratory, annual technical progress report of ecological research for the year ending June 30, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Wein, G.; Rosier, B.

    1997-12-31

    This report provides an overview of the research programs and program components carried out by the Savannah River Ecology Laboratory. Research focused on the following: advanced analytical and spectroscopic techniques for developing novel waste isolation and stabilization technologies as well as cost-effective remediation strategies; ecologically sound management of damaged and remediation of ecological systems; ecotoxicology, remediation, and risk assessment; radioecology, including dose assessments for plants and animals exposed to environmental radiation; and other research support programs.

  7. Savannah River Ecology Laboratory, annual technical progress report of ecological research for the year ending June 30, 1998

    Energy Technology Data Exchange (ETDEWEB)

    Wein, G.; Rosier, B.

    1998-12-31

    This report provides an overview of the research programs and program components carried out by the Savannah River Ecology Laboratory. Research focused on the following: advanced analytical and spectroscopic techniques for developing novel waste isolation and stabilization technologies as well as cost-effective remediation strategies; ecologically sound management of damaged and remediation of ecological systems; ecotoxicology, remediation, and risk assessment; radioecology, including dose assessments for plants and animals exposed to environmental radiation; and other research support programs.

  8. Savannah River Ecology Laboratory, annual technical progress report of ecological research for the year ending June 30, 1997

    International Nuclear Information System (INIS)

    This report provides an overview of the research programs and program components carried out by the Savannah River Ecology Laboratory. Research focused on the following: advanced analytical and spectroscopic techniques for developing novel waste isolation and stabilization technologies as well as cost-effective remediation strategies; ecologically sound management of damaged and remediation of ecological systems; ecotoxicology, remediation, and risk assessment; radioecology, including dose assessments for plants and animals exposed to environmental radiation; and other research support programs

  9. Savannah River Ecology Laboratory annual technical progress report of ecological research for the year ending July 31, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.H.

    1995-07-01

    The Savannah River Ecology Laboratory (SREL) is a research unit of the University of Georgia (UGA). The overall mission of the Laboratory is to acquire and communicate knowledge of ecological processes and principles. SREL conducts basic and applied ecological research, as well as education and outreach programs, under a contract with the US Department of Energy (DOE) at the Savannah River Site near Aiken, South Carolina. Significant accomplishments were made during the past year in the areas of research, education and service. Major additions to SREL Facilities were completed that will enhance the Laboratory`s work in the future. Following several years of planning, opening ceremonies were held for the 5000 ft{sup 2} multi-purpose conference center that was funded by the University of Georgia Research Foundation (UGARF). The center is located on 68 acres of land that was provided by the US Department of Energy. This joint effort between DOE and UGARF supports DOE`s new initiative to develop partnerships with the private sector and universities. The facility is being used for scientific meetings and environmental education programs for students, teachers and the general public. A 6000 ft{sup 2} office and library addition to S@s main building officially opened this year, and construction plans are underway on a new animal care facility, laboratory addition, and receiving building.

  10. A laboratory based experimental study of mercury emission from contaminated soils in the River Idrijca catchment

    Directory of Open Access Journals (Sweden)

    D. Kocman

    2010-02-01

    Full Text Available Results obtained by a laboratory flux measurement system (LFMS focused on investigating the kinetics of the mercury emission flux (MEF from contaminated soils of the Idrija Hg-mine region, Slovenia are presented. Representative soil samples with respect to total Hg concentrations (4–417 μg g−1 and land cover (forest, meadow and alluvial soil alongside the River Idrijca were analysed to determine the variation in MEF versus distance from the source, regulating three major environmental parameters comprising soil temperature, soil moisture and solar radiation. MEFs ranged from less than 2 to 530 ng m−2 h−1, with the highest emissions from contaminated alluvial soils and soils near the mining district in the town of Idrija. A significant decrease of MEF was then observed with increasing distance from these sites. The results revealed a strong positive effect of all three parameters investigated on momentum MEF. The light-induced flux was shown to be independent of the soil temperature, while the soil aqueous phase seems to be responsible for recharging the pool of mercury in the soil available for both the light- and thermally-induced flux. The overall flux response to simulated environmental conditions depends greatly on the form of Hg in the soil. Higher activation energies are required for the overall process to occur in soils where insoluble cinnabar prevails compared to soils where more mobile Hg forms and forms available for transformation processes are dominant.

  11. Laboratory analysis of diet of Pacific harbor seals at Umpqua River, Oregon and Columbia River, Oregon/Washington conducted from 1994-06-23 to 2005-09-03 (NCEI Accession 0139413)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — From 1994 to 2005, The National Marine Mammal Laboratories' California Current Ecosystem Program (AFSC/NOAA) collected fecal samples at the Umpqua River, Oregon and...

  12. Horizontal wells up odds for profit in Giddings Austin chalk

    International Nuclear Information System (INIS)

    This paper reports on horizontal drilling in the Giddings field Austin chalk which has significantly improved average well recoveries and more than offset increased drilling costs. Although not the panacea originally promoted, horizontal drilling, in Giddings field, offers economic profits to the average investor. Economic analysis indicates that the typical investor is making money by earning returns in excess of market values. Field-wide development will, therefore, remain active unless oil prices or average well recoveries fall below $12/bbl or 112,000 bbl of oil equivalent (BOE), respectively. The application of technological innovation in the Giddings field may culminate in the drilling of over 2,000 horizontal Austin chalk wells, and has conceivably increased recoverable reserves by 400 million BOE

  13. Change in Biot's effective stress coefficient of chalk during pore collapse

    DEFF Research Database (Denmark)

    Alam, M. Monzurul; Fabricius, Ida Lykke

    2013-01-01

    grains could also change during elastic deformation of the grains in a rock mechanics test. Diagenetic change in grain contact cement of chalk can be compared with stress-induced change in the laboratory. The change in porosity is studied with reference to the change in effective stress on grain contacts...... porosity reduces at a slower rate. We noticed that presence of non carbonates and hydrocarbon could increase σ'm. During rock mechanics test in the lab, with increased applied stress, σ'm increases, Biot's effective stress coefficient shows a decreasing trend, while a minor porosity reduction was observed......Biot's effective stress coefficient (α) is a measure of how well grains in the rocks are connected with each other. The amount of contact cements between the grains determines the stiffness of rocks. Change in grain contact occurs during natural diagenesis of sedimentary rock. Contact between the...

  14. Environmental assessment of Chalk Point cooling tower drift and vapor emissions

    Energy Technology Data Exchange (ETDEWEB)

    Davis, E.A.

    1979-03-01

    An assessment is provided of selected environmental effects of operating the cooling towers and stacks of Units No. 3 and No. 4 of the Potomac Electric Power Company's generating station at Chalk Point, Maryland. The emphasis is on the magnitude of salt deposition to the area surrounding the cooling tower due to saline water drift. A secondary but important consideration is the magnitude of salt loading due to saline drift from the stack which uses saline river water in scrubbing flue gases. This salt loading together with that of the ambient salt background is assessed for its effects on soils, crops, native vegetation and man-made structures. Other atmospheric effects examined are: enhancement of ground level fogging and icing, enhancement of precipitation, and the flight hazards to aircraft. A numerical model of drift deposition has been developed and validated against the data collected in the Dyed Drift Experiment at Chalk Point. Use of the available data model predictions indicate that with fulltime, full load operation of both 600 MW(e) units significant levels of salt deposition occur only on the plant site within 0.4 km of the source. The predicted maximum salt deposition rates are given. The effects on soils, crops and native vegetation are predicted to be negligible at off-site locations. Significant effects to foliage of dogwood is predicted to occur at the most impacted on-site locations. Corrosion of structures at these locations could be enhanced under conditions of heavy plant operation. Enhancement of ground-level fogging, icing, and precipitation is expected to be negligible for all conditions of plant use. Hazards to aircraft because of restricted visibility, turbulence, and icing of structures and engines are estimated to be very slight and of no consequence.

  15. Savannah River Ecology Laboratory annual technical progress report of ecological research for the year ending July 31, 1995

    International Nuclear Information System (INIS)

    The Savannah River Ecology Laboratory (SREL) is a research unit of the University of Georgia (UGA). The overall mission of the Laboratory is to acquire and communicate knowledge of ecological processes and principles. SREL conducts basic and applied ecological research, as well as education and outreach programs, under a contract with the US Department of Energy (DOE) at the Savannah River Site near Aiken, South Carolina. Significant accomplishments were made during the past year in the areas of research, education and service. Major additions to SREL Facilities were completed that will enhance the Laboratory's work in the future. Following several years of planning, opening ceremonies were held for the 5000 ft2 multi-purpose conference center that was funded by the University of Georgia Research Foundation (UGARF). The center is located on 68 acres of land that was provided by the US Department of Energy. This joint effort between DOE and UGARF supports DOE's new initiative to develop partnerships with the private sector and universities. The facility is being used for scientific meetings and environmental education programs for students, teachers and the general public. A 6000 ft2 office and library addition to S at sign s main building officially opened this year, and construction plans are underway on a new animal care facility, laboratory addition, and receiving building

  16. Understanding groundwater, surface water, and hyporheic zone biogeochemical processes in a Chalk catchment using fluorescence properties of dissolved and colloidal organic matter

    Science.gov (United States)

    Lapworth, D. J.; Gooddy, D. C.; Allen, D.; Old, G. H.

    2009-09-01

    Understanding groundwater-surface water (GW-SW) interaction in Chalk catchments is complicated by the degree of geological heterogeneity. At this study site, in southern United Kingdom, alluvial deposits in the riparian zone can be considered as a patchwork of varying grades and types with an equally varied lateral connectivity. Some display good connection with the river system and others good connection with the groundwater system and, by definition, poorer connectivity with the surface water. By coupling tangential flow fractionation (TFF) with fluorescence analysis we were able to characterize the organic matter in the river and hyporheic zone. There is a significant proportion of particulate and colloidal fluorescent organic matter (FOM) within the river system and at depth within the gravels beneath the river channel. At depth in the hyporheic zone, the surface water inputs are dampened by mixing with deeper groundwater FOM. The shallow (0-0.5 m below river bed) hyporheic zone is highly dynamic as a result of changing surface water inputs from upstream processes. Labile C in the form of protein-like FOM appears to be attenuated preferentially compared to fulvic-like fluorescence in the hyporheic zone compared to the adjacent gravel and sand deposits. These preliminary findings have important implications for understanding nutrient and trace element mobility and attenuation within the groundwater, surface water, and hyporheic zone of permeable Chalk catchments. Fluorescence analysis of dissolved organic matter has been shown to be a useful environmental tracer that can be used in conjunction with other methods to understand GW-SW processes within a permeable Chalk catchment.

  17. Impacts of climate change on in-stream nitrogen in a lowland chalk stream. An appraisal of adaptation strategies

    Energy Technology Data Exchange (ETDEWEB)

    Whitehead, P.G.; Butterfield, D.; Wade, A.J. [Aquatic Environments Research Centre, Department of Geography, University of Reading, Reading, RG6 6AB (United Kingdom); Wilby, R.L. [Environment Agency, Trentside Office, Scarrington Road, West Bridgford, Nottingham, NG2 5FA (United Kingdom)

    2006-07-15

    The impacts of climate change on nitrogen (N) in a lowland chalk stream are investigated using a dynamic modelling approach. The INCA-N model is used to simulate transient daily hydrology and water quality in the River Kennet using temperature and precipitation scenarios downscaled from the General Circulation Model (GCM) output for the period 1961-2100. The three GCMs (CGCM2, CSIRO and HadCM3) yield very different river flow regimes with the latter projecting significant periods of drought in the second half of the 21st century. Stream-water N concentrations increase over time as higher temperatures enhance N release from the soil, and lower river flows reduce the dilution capacity of the river. Particular problems are shown to occur following severe droughts when N mineralization is high and the subsequent breaking of the drought releases high nitrate loads into the river system. Possible strategies for reducing climate-driven N loads are explored using INCA-N. The measures include land use change or fertiliser reduction, reduction in atmospheric nitrate and ammonium deposition, and the introduction of water meadows or connected wetlands adjacent to the river. The most effective strategy is to change land use or reduce fertiliser use, followed by water meadow creation, and atmospheric pollution controls. Finally, a combined approach involving all three strategies is investigated and shown to reduce in-stream nitrate concentrations to those pre-1950s even under climate change. (author)

  18. Stratigraphy of the unsaturated zone and the Snake River Plain aquifer at and near the Idaho National Engineering Laboratory, Idaho

    International Nuclear Information System (INIS)

    The unsaturated zone and the Snake River Plain aquifer at and near the Idaho National Engineering Laboratory (INEL) are made up of at least 178 basalt-flow groups, 103 sedimentary interbeds, 6 andesite-flow groups, and 4 rhyolite domes. Stratigraphic units identified in 333 wells in this 890-mile2 area include 121 basalt-flow groups, 102 sedimentary interbeds, 6 andesite-flow groups, and 1 rhyolite dome. Stratigraphic units were identified and correlated using the data from numerous outcrops and 26 continuous cores and 328 natural-gamma logs available in December 1993. Basalt flows make up about 85% of the volume of deposits underlying the area

  19. Diagenetic Variations between Upper Cretaceous Outcrop and Deeply Buried Reservoir Chalks of the North Sea Area

    DEFF Research Database (Denmark)

    Hjuler, Morten Leth; Fabricius, Ida Lykke

    2007-01-01

    -particle connections and less altered particle shapes. The non-carbonate mineralogy of outcrop chalks is dominated by quartz, occasionally opal-CT and clinoptilolite, and the clay mineral smectite. In offshore chalks quartz still dominates, opal-CT has recrystallized into submicron-size quartz crystals and smectite...

  20. Current oil and gas production from North American Upper Cretaceous Chalks

    Energy Technology Data Exchange (ETDEWEB)

    Scholle, P.A.

    1977-01-01

    Production of oil and natural gas from North American chalks has increased significantly during the past five years. Chalk reservoirs have been discovered in the Gulf Coast in the Austin Group, Saratoga and Annona Chalks, Ozan Formation, Selma Group, Monroe gas rock, (an informal unit of Navarro age), and other Upper Cretaceous units. In the Western Interior, production has been obtained from the Cretaceous Niobrara and Greenhorn Formations. Significant discoveries of natural gas and gas condensate also have been made in the Upper Cretaceous Wyandot Formation on the Scotian Shelf of eastern Canada. All North American chalk units share a similar depositional and diagenetic history. The diagenetic history of a chalk is critical in determining its reservoir potential. All chalk has a stable composition (low-Mg calcite) and very high primary porosity. With subsequent burial, mechanical and chemical (solution-transfer) compaction can reduce or completely eliminate pore space. The degree of loss of primary porosity in chalk sections is normally a direct function of the maximum depth to which it has been buried. Pore-water chemistry, pore-fluid pressures, and tectonic stresses also influence rates of cementation. Oil or gas reservoirs of North American chalk fall into three main groups: 1. Areas with thin overburden and significant primary porosity retention. 2. Areas with thicker overburden but considerable fracturing. 3. Areas with thick overburden in which marine pore fluids have been retained.

  1. Savannah River Ecology Laboratory annual technical progress report of ecological research, period ending July 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Vaitkus, M.R.; Wein, G.R. [eds.; Johnson, G.

    1993-11-01

    This progress report gives an overview of research programs at the Savannah River Site. Topics include; environmental operations support, wood stork foraging and breeding, defense waste processing, environmental stresses, alterations in the environment due to pollutants, wetland ecology, biodiversity, pond drawdown studies, and environmental toxicology.

  2. Dynamic up-scaling of relative permeability in chalk

    Energy Technology Data Exchange (ETDEWEB)

    Frykman, P.; Lindgaard, H.F.

    1997-12-31

    This paper describes how fine-scale geo-statistic reservoir models can be utilised for the up-scaling of two-phase flow properties, including both relative permeability and capillary pressure function. The procedure is applied to a North Sea chalk carbonate reservoir example, which is a high-porosity/low-permeability reservoir type. The study focuses on waterflooding as the main recovery scheme and for the given flow regime in the reservoir. The main purpose of the paper is to demonstrate the use of dynamic multi-step up-scaling methods in the preparation of detailed geological information for full field reservoir simulation studies. (au) EFP-96. 39 refs.

  3. The Effect of Bacteria Penetration on Chalk Permeability

    DEFF Research Database (Denmark)

    Halim, Amalia Yunita; Shapiro, Alexander; Nielsen, Sidsel Marie;

    , the spore forming Bacillus licheniformis 421 and the non-spore forming Pseudomonas putida K12, were used. The core plugs were Stevns Klint outcrop with initial permeability at 2-4 mD. The results revealed that bacteria were able to penetrate and to be transported through the chalk. Furthermore, a...... higher number of B. licheniformis was detected on the effluent compared with P. putida. However, in the experiment with B. licheniformis mainly spores were detected in the effluent. The core permeability decreased rapidly during injection of bacteria and a starvation period of 12 days did not allow the...... permeability to return to initial condition....

  4. Advanced waterflooding in chalk reservoirs: Understanding of underlying mechanisms

    DEFF Research Database (Denmark)

    Zahid, Adeel; Sandersen, Sara Bülow; Stenby, Erling Halfdan;

    2011-01-01

    pressure. We have also observed formation of a microemulsion phase between brine and oil with the increase in sulfate ion concentration at high temperature and pressure. In addition, sulfate ions can reduce interfacial tension (IFT) between oil and water. We propose that the decrease in viscosity and...... formation of a microemulsion phase could be the possible reasons for the observed increase in oil recovery with sulfate ions at high temperature in chalk reservoirs besides the mechanism of the rock wettability alteration, which has been reported in most previous studies....

  5. Origin of channel systems in the Upper Cretaceous chalk group of the Paris Basin

    DEFF Research Database (Denmark)

    Esmerode, E. V.; Surlyk, Finn

    2009-01-01

    presence of at least two distinct intra-chalk discordant reflections: a Top Santonian and a Mid-Campanian reflection. These reflections are in places associated with up to 120-m-deep channel-like structures trending preferentially N-S and NW-SE. The Mid-Campanian reflection is also sporadically associated......The Upper Cretaceous Chalk Group of the Anglo-Paris Basin is known to show wedging beds and channel-like features which disrupt the quietly deposited pelagic chalk that covered most of NW Europe in the Late Cretaceous. Two-D reflection seismic data from the Brie region, SE of Paris, show the...... collapse of the Cenozoic succession over the channel-like features as a result of intra-chalk dissolution. Both reflections correlate with indurated chalk layers and hardgrounds, and represent real unconformities. The Mid-Campanian reflection is furthermore associated with a stratigraphic hiatus. A...

  6. Improved Oil Recovery in Chalk. Spontaneous Imbibition affected by Wettability, Rock Framework and Interfacial Tension

    Energy Technology Data Exchange (ETDEWEB)

    Milter, J.

    1996-12-31

    The author of this doctoral thesis aims to improve the oil recovery from fractured chalk reservoirs, i.e., maximize the area of swept zones and their displacement efficiencies. In order to identify an improved oil recovery method in chalk, it is necessary to study wettability of calcium carbonate and spontaneous imbibition potential. The thesis contains an investigation of thin films and wettability of single calcite surfaces. The results of thin film experiments are used to evaluate spontaneous imbibition experiments in different chalk types. The chalk types were described detailed enough to permit considering the influence of texture, pore size and pore throat size distributions, pore geometry, and surface roughness on wettability and spontaneous imbibition. Finally, impacts of interfacial tension by adding anionic and cationic surfactants to the imbibing water phase are studied at different wettabilities of a well known chalk material. 232 refs., 97 figs., 13 tabs.

  7. Laboratory And Lysimeter Experimentation And Transport Modeling Of Neptunium And Strontium In Savannah River Site Sediments

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, Daniel I.; Powell, B. A.; Miller, Todd J.

    2012-09-24

    The Savannah River Site (SRS) conducts performance assessment (PA) calculations to determine the appropriate amount of low-level radiological waste that can be safely disposed on site. Parameters are included in these calculations that account for the interaction between the immobile solid phase and the mobile aqueous phase. These parameters are either the distribution coefficient (K{sub d} value) or the apparent solubility value (K{sub sp}). These parameters are readily found in the literature and are used throughout the DOE complex. One shortcoming of K{sub d} values is that they are only applicable to a given set of solid and aqueous phase conditions. Therefore, a given radionuclide may have several K{sub d} values as it moves between formations and comes into contact with different solids and different aqueous phases. It is expected that the K{sub d} construct will be appropriate to use for a majority of the PA and for a majority of the radionuclides. However, semi-mechanistic models would be more representative in isolated cases where the chemistry is especially transitory or the radionuclide chemistry is especially complex, bringing to bear multiple species of varying sorption tendencies to the sediment. Semi-mechanistic models explicitly accommodate the dependency of K{sub d} values, or other sorption parameters, on contaminant concentration, competing ion concentrations, pH-dependent surface charge on the adsorbent, and solute species distribution. Incorporating semi-mechanistic concepts into geochemical models is desirable to make the models more robust and technically defensible. Furthermore, these alternative models could be used to augment or validate a Kd?based DOE Order 435.1 Performance Assessment. The objectives of this study were to: 1) develop a quantitative thermodynamically-based model for neptunium sorption to SRS sediments, and 2) determine a sorption constant from an SRS 11-year lysimeter study. The modeling studies were conducted with

  8. Summary of the Mol electrolysis cell test program in the CRL tritium laboratory

    International Nuclear Information System (INIS)

    The development of electrolysis technology for highly tritiated water at the Studiecentrum voor Kernenergie/Centre d'Etude de l'Energie Nucleaire (SCK/CEN), Mol, Belgium, focused on A Low Inventory Capillary Electrolyser (ALICE). The key characteristic of ALICE is its low liquid inventory, a key feature for the radio-toxicity of tritiated water. A program to test this electrolytic cell design with highly tritiated water in the Chalk River Tritium Laboratory was initiated in 1988 and extended through to early 1995. The activities conducted at CRL and associated with the experimental program-design, installation, licensing and commissioning activities- are described in this report along with the results of the test program conducted on the experimental system with non-tritiated heavy water. The installation in the CRL Tritium Laboratory consisted of three main sections: the electrolysis section, the tritium storage and supply section, and the recombination section. 16 figs., 2 tabs., 10 refs

  9. Geochemical criteria for reservoir quality variations in chalk from the North Sea

    International Nuclear Information System (INIS)

    The influence of chalk geochemistry on petrophysical parameters determining porosity and permeability is investigated. The central well TWB-8 and eastern marginal well E-lx of the North Sea Tyra gas field were chosen. Drill core sections of Upper Maastrichtian and Danian chalk were selected. Chemical data on chalk samples were gathered by using X-ray fluorescence and instrumental neutron activation. Geochemical data are compared with the well-logging results. Geophysical logging suggests that there is reduced porosity in the Danian reservoir units LDP and UDT in both wells. The chalk drill core samples from the section with reduced porosity also show a lower Ca content. A high Si content is observed in these samples and a number of trace elements in chalk show a similar distribution with depth. Reservoir porosity may be estimated from the Si content of chalk. Chalk permeability may also be elements Al, Fe and Sc show the same trends as that for Si. Diagenetic changes in chalk also include clay minerals. The gas zone in TWB-8 is characterized by low contents of Na and Cl, i.e. lower water saturation is indicated. Low concentrations of rare earths in all chalk samples show a shale-normalized pattern that is characteristic of marine sediments laid down under oxic conditions. Some changes that occur with depth in the Ce anomaly may indicate a slight change in the depositional environment. The content of manganese continuously decreases with depth, from Danian (about 2000 ppm) to Maastrichtian strata (less than 200 ppm). In this respect, no other chemical element in chalk correlates with Mn. There is no indication as to which mineral or mineral phase one is likely to find in the element. (AB) 14 tabs., 49 ills., 147 refs

  10. Transformation of organic micropollutants during river bank filtration: Laboratory versus field data

    OpenAIRE

    Bertelkamp, C.; Reungoat, J.; Botton, S.; Cornelissen, E; Ghadiri, E.; de Jonge, M; Singhal, N.; Hoek, J. P.; A. R. D. Verliefde

    2012-01-01

    This paper investigates the degradation behavior of 14 organic micropoliutants (OMPs), selected for their different physico-chemical properties (e.g., molecular weight, hydrophobicity and charge). In soil columns simulating the conditions prevailing in the first meter of river bank filtration (RBF) media. The results from the column system are compared to RBF field data obtained from the Vitens drinking water company in The Netherlands. The study explores the role of sorption media (sand fill...

  11. Assessment of toxicity of radioactively contaminated sediments of the Yenisei River for aquatic plants in laboratory assay

    Energy Technology Data Exchange (ETDEWEB)

    Zotina, T.; Trofimova, E.; Medvedeva, M.; Bolsunovsky, A. [Institute of Biophysic SB RAS (Russian Federation)

    2014-07-01

    abnormalities in apices of elodea roots (%) served as a genotoxicity indicator. Considerable growth of shoots and roots occurred for 12-14 days of experiments. Positive correlation of the rate of chromosome abnormalities (p<0.05) with radionuclide activity concentration (total, artificial, and Cs-137) in samples of bottom sediments was revealed, suggesting mutagenic effect of radiation dose. Shoot length endpoints negatively correlated (p<0.05) with radionuclide concentration in samples of bottom sediments although the mechanism of this effect is unclear. Endpoints of shoot length negatively correlated with the rate of chromosome abnormalities as well. No correlation of plant endpoints with concentration of heavy metals in bottom sediments was revealed. Root endpoints were the most variable among other endpoints, but they did not correlate with radionuclide activity concentration in sediments. Hence, we can conclude that correlation of the rate of chromosome abnormalities in the roots of elodea with concentration of radionuclides (total and artificial) in bottom sediments can be treated as low dose effects and can be recommended as a sensitive endpoint for laboratory bioassay. The response of shoot length endpoints to radiological factor in bottom sediments of the Yenisei River needs further elucidation. Document available in abstract form only. (authors)

  12. RadBall™ Technology Testing in the Savannah River Site’s Health Physics Instrument Calibration Laboratory

    Science.gov (United States)

    Farfán, Eduardo B.; Foley, Trevor Q.; Jannik, G. Timothy; Harpring, Larry J.; Gordon, John R.; Blessing, Ronald; Coleman, J. Rusty; Holmes, Christopher J.; Oldham, Mark; Adamovics, John; Stanley, Steven J.

    2010-01-01

    The United Kingdom’s National Nuclear Laboratory (NNL) has developed a radiation-mapping device that can locate and quantify radioactive hazards within contaminated areas of the nuclear industry. The device, known as RadBall™, consists of a colander-like outer collimator that houses a radiation-sensitive polymer sphere. The collimator has over two hundred small holes; thus, specific areas of the polymer sphere are exposed to radiation becoming increasingly more opaque in proportion to the absorbed dose. The polymer sphere is imaged in an optical-CT scanner that produces a high resolution 3D map of optical attenuation coefficients. Subsequent analysis of the optical attenuation data provides information on the spatial distribution of sources in a given area forming a 3D characterization of the area of interest. The RadBall™ technology has been deployed in a number of technology trials in nuclear waste reprocessing plants at Sellafield in the United Kingdom and facilities of the Savannah River National Laboratory (SRNL). This paper summarizes the tests completed at SRNL Health Physics Instrument Calibration Laboratory (HPICL). PMID:21617738

  13. Energy Materials Research Laboratory (EMRL)

    Data.gov (United States)

    Federal Laboratory Consortium — The Energy Materials Research Laboratory at the Savannah River National Laboratory (SRNL) creates a cross-disciplinary laboratory facility that lends itself to the...

  14. Preliminary delineation of natural geochemical reactions, Snake River Plain aquifer system, Idaho National Engineering Laboratory and vicinity, Idaho

    International Nuclear Information System (INIS)

    The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, is conducting a study to determine the natural geochemistry of the Snake River Plain aquifer system at the Idaho National Engineering Laboratory (INEL), Idaho. As part of this study, a group of geochemical reactions that partially control the natural chemistry of ground water at the INEL were identified. Mineralogy of the aquifer matrix was determined using X-ray diffraction and thin-section analysis and theoretical stabilities of the minerals were used to identify potential solid-phase reactants and products of the reactions. The reactants and products that have an important contribution to the natural geochemistry include labradorite, olivine, pyroxene, smectite, calcite, ferric oxyhydroxide, and several silica phases. To further identify the reactions, analyses of 22 representative water samples from sites tapping the Snake River Plain aquifer system were used to determine the thermodynamic condition of the ground water relative to the minerals in the framework of the aquifer system. Principal reactions modifying the natural geochemical system include congruent dissolution of olivine, diopside, amorphous silica, and anhydrite; incongruent dissolution of labradorite with calcium montmorillonite as a residual product; precipitation of calcite and ferric oxyhydroxide; and oxidation of ferrous iron to ferric iron. Cation exchange reactions retard the downward movement of heavy, multivalent waste constituents where infiltration ponds are used for waste disposal

  15. A parameter identifiability study of two chalk tracer tests

    Directory of Open Access Journals (Sweden)

    S. A. Mathias

    2006-08-01

    Full Text Available As with most fractured rock formations, Chalk is highly heterogeneous. Therefore, meaningful estimates of model parameters must be obtained at a scale comparable with the process of concern. These are frequently obtained by calibrating an appropriate model to observed concentration-time data from radially convergent tracer tests (RCTT. Arguably, an appropriate model should consider radially convergent dispersion (RCD and Fickian matrix diffusion. Such a model requires the estimation of at least four parameters. A question arises as to whether or not this level of model complexity is supported by the information contained within the calibration data. Generally modellers have not answered this question due to the calibration techniques employed. A dual-porosity model with RCD was calibrated to two tracer test datasets from different UK Chalk aquifers. A multivariate sensitivity analysis, which assumed only a priori upper and lower bounds for each model parameter, was undertaken. Rather than looking at measures of uncertainty, the shape of the multivariate objective function surface was used to determine whether a parameter was identifiable. Non-identifiable parameters were then removed and the procedure was repeated until all remaining parameters were identifiable.

    It was found that the single fracture model (SFM (which ignores mechanical dispersion obtained the best mass recovery, excellent model performance and best parameter identifiability in both the tests studied. However, there was no objective evidence suggesting that mechanical dispersion was negligible. Moreover, the SFM (with just two parameters was found to be good at approximating the Single Fracture Dispersion Model SFDM (with three parameters when different, and potentially erroneous parameters, were used. Overall, this study emphasises the importance of adequate temporal sampling of breakthrough curve data prior to peak concentrations, to ensure adequate characterisation of

  16. Hydro-chemistry of paleontology of depression of Tajikistan in Late chalk period

    International Nuclear Information System (INIS)

    In this chapter authors made conclusion that on formation of clayey layers of upper chalk did influence following factors: shallow sea basin and its relatively small dimensions, climate aridity, relatively nearness nutrition areas, frequent change sea transgressions its recessions

  17. Statement of Basis/Proposal Plan for West of Savannah River Ecology Laboratory Georgia Fields Site (631-19G) Operable Unit

    International Nuclear Information System (INIS)

    The purpose of this Statement of Basis/Proposed Plan (SB/PP) is to describe the preferred remedial alternative(s) for the West of Savannah River Ecology Laboratory (SREL) Georgia Fields Site (631-19G) Operable Unit (GFS) and to provide for public involvement in the decision-making process

  18. DECOMMISSIONING THE PHYSICS LABORATORY, BUILDING 777-10A, AT THE SAVANNAH RIVER SITE (SRS)

    Energy Technology Data Exchange (ETDEWEB)

    Musall, J; Cathy Sizemore, C

    2007-01-17

    SRS recently completed a four-year mission to decommission {approx}250 excess facilities. As part of that effort, SRS decommissioned a 48,000 ft{sup 2} laboratory that housed four low-power test reactors, formerly used by SRS to determine reactor physics. This paper describes and reviews the decommissioning, with a focus on component segmentation and handling (i.e. hazardous material removal, demolition, and waste handling). The paper is intended to be a resource for engineers, planners, and project managers who face similar decommissioning challenges.

  19. Laboratory model of radionuclide migration in the aeration zone of country between Uzh and Pripyat' rivers

    International Nuclear Information System (INIS)

    Special installation for modelling of the radionuclide migration in the aeration zone was presented to predict the ground water state in the Chernobyl' accident region. This installation was under operation in the Chernobyl' radiochemical laboratory from 1987, September. Results of the first stage of experiment have shown that the level of total beta-activity of recharge run-off samples is 10-9 Ci/l, while the total beta-activity of model 'ground water' is half an order less in average. Cs-137, Cs-134, Ce-144, Ru-106 radionuclides were found in run-off samples. 7 figs

  20. Change of Static and Dynamic Elastic Properties due to CO² Injection in North Sea Chalk

    OpenAIRE

    Alam, Mohammad Monzurul; Hjuler, M.L.; Christensen, H.F.; Fabricius, Ida Lykke

    2012-01-01

    Reservoir modeling and monitoring uses dynamic data for predicting and determining static changes. Dynamic data are achieved from the propagation velocity of elastic waves in rock while static data are obtained from the mechanical deformation. Reservoir simulation and monitoring are particularly importantin enhanced oil recovery by CO2 injection (CO2-EOR) in chalk as, chalk reservoirs are vulnerable to compaction under changed stress and pore fluid. From South Arne field, North Sea, we used E...

  1. Investigated Miscible CO2 Flooding for Enhancing Oil Recovery in Wettability Altered Chalk and Sandstone Rocks

    OpenAIRE

    Tabrizy, Vahid Alipour

    2012-01-01

    The thesis addresses oil recovery by miscible CO2 flooding from modified sandstone and chalk rocks. Calcite mineral surface is modified with stearic acid (SA) and asphaltene, and the silicate mineral surfaces are modified with N,N-dimethyldodecylamine (NN-DMDA) and asphaltene. The stability of adsorbed polar components in presence of SO4 2- and Mg2 + ions is also investigated. Recovery from sandstone cores is consistently lower than that from chalk cores saturated with...

  2. Persistent and emerging micro-organic contaminants in Chalk groundwater of England and France

    International Nuclear Information System (INIS)

    The Chalk aquifer of Northern Europe is an internationally important source of drinking water and sustains baseflow for surface water ecosystems. The areal distribution of microorganic (MO) contaminants, particularly non-regulated emerging MOs, in this aquifer is poorly understood. This study presents results from a reconnaissance survey of MOs in Chalk groundwater, including pharmaceuticals, personal care products and pesticides and their transformation products, conducted across the major Chalk aquifers of England and France. Data from a total of 345 sites collected during 2011 were included in this study to provide a representative baseline assessment of MO occurrence in groundwater. A suite of 42 MOs were analysed for at each site including industrial compounds (n = 16), pesticides (n = 14) and pharmaceuticals, personal care and lifestyle products (n = 12). Occurrence data is evaluated in relation to land use, aquifer exposure, well depth and depth to groundwater to provide an understanding of vulnerable groundwater settings. - Highlights: • Broad range of microorganics detected in Chalk groundwater in England and France. • Plasticisers, pesticides, BPA and THM detected at the highest concentrations. • Pesticides higher in outcrop Chalk, caffeine and BPA at concealed sites. • Occurrences show some relationship to land use, borehole depth and water level. - Broad screening reveals for the first time the extent of emerging microorganic pollution in Chalk groundwater sources across England and France

  3. Laboratory tests of a modified {sup 3}He detector for use with startup instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Qian, T.; Tonner, P.; Keller, N. [Atomic Eerngy of Canada Limited, Chalk River, ON (Canada)] [and others

    1997-07-01

    Boron trifluoride (BF{sub 3}) detectors are currently used in all CANDU stations as startup instrumentation (SUI) detectors for monitoring neutron flux during extended outages and startups. Experience at some CANDU stations has shown that some models of BF{sub 3} detectors degrade quickly, even in moderate neutron and gamma fields. Degradation and life expectancy tests for five models of BF{sub 3} detectors from different manufacturers were performed at Chalk River Laboratories (CRL) to investigate the problem. The test results reveal that most BF{sub 3} detectors have low neutron and gamma durability, and some exhibit an undesirable time-dependent degradation followed by recovery. As a result of this finding, other detector options including a modified helium ({sup 3}He) detector described herein were investigated. Modified {sup 3}He detectors were procured from an established supplier and were found to perform without degradation in neutron and gamma fields. (author)

  4. Laboratory tests of a modified 3He detector for use with startup instrumentation

    International Nuclear Information System (INIS)

    Boron trifluoride (BF3) detectors are currently used in all CANDU stations as startup instrumentation (SUI) detectors for monitoring neutron flux during extended outages and startups. Experience at some CANDU stations has shown that some models of BF3 detectors degrade quickly, even in moderate neutron and gamma fields. Degradation and life expectancy tests for five models of BF3 detectors from different manufacturers were performed at Chalk River Laboratories (CRL) to investigate the problem. The test results reveal that most BF3 detectors have low neutron and gamma durability, and some exhibit an undesirable time-dependent degradation followed by recovery. As a result of this finding, other detector options including a modified helium (3He) detector described herein were investigated. Modified 3He detectors were procured from an established supplier and were found to perform without degradation in neutron and gamma fields. (author)

  5. Multi-model comparison of a major flood in the groundwater-fed basin of the Somme River (France)

    OpenAIRE

    Habets, F.; S. Gascoin; S. Korkmaz; Thiéry, D.; Zribi, M.; Amraoui, N.; Carli, M; Ducharne, A; E. Leblois; E. Ledoux; martin, E.; Noilhan, J.; Ottlé, C; Viennot, P.

    2010-01-01

    The Somme River Basin is located above a chalk aquifer and the discharge of the somme River is highly influenced by groundwater inflow (90% of river discharge is baseflow). In 2001, the Somme River Basin suffered from a major flood causing damages estimated to 100 million euro (Deneux and Martin, 2001). The purpose of the present research is to evaluate the ability of four hydrologic models to reproduce flood events in the Somme River Basin over an 18-year period, by comparison...

  6. Performance of sand filters for the separations areas at the Savannah River Laboratory

    International Nuclear Information System (INIS)

    Two new large sand filters, 30.5 by 100 m, were constructed and put into service at the Savannah River Plant (SRP) in 1975 and 1976. These units were designed to provide final filtration of process air - one for each of the two separations areas. Eventual flow will be 4950 m3/min (205,000 scfm) on each unit when all facilities are connected. They were built as replacements for the original sand filters that began operation in 1954 and 1955. The new filters have been operated in parallel with the old units following partial failure of the old units from acid attack and erosion of the concrete support structure for the sand beds. The design of the new units was based on extensive tests at SRP on characteristics of different sands. The performance of the new filters meets criteria for pressure drop, flow capacity, and efficiency. The efficiencies measured by DOP test are greater than 99.98%. Parallel operation reduces air velocity through the beds, which increases efficiency. A characteristic of sand filter performance has been low apparent efficiency at low input; efficiency increases as the activity input rises. This is attributed to a small entrainment release from the large amount of activity already sorbed on the filter; this release controls and lowers the calculated efficiency at low input. An analysis of efficiency as a function of input activity projects efficiencies greater than 99.99% for large inputs that might be characteristic of large internal accidents. The data indicate that DOP efficiencies can be used in hazards analyses to determine accident consequences. Routine evaluation of filter releases can be used for surveillance to establish that performance is normal at other times

  7. Straddle-packer aquifer test analyses of the Snake River Plain aquifer at the Idaho National Engineering Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, G.S.; Frederick, D.B.

    1997-01-01

    The State of Idaho INEL Oversight Program, with the University of Idaho, Idaho State University, Boise State University, and the Idaho Geologic Survey, used a straddle-packer system to investigate vertical variations in characteristics of the Snake River Plain aquifer at the Idaho National Engineering Laboratory in southeast Idaho. Sixteen single-well aquifer tests were conducted on.isolated intervals in three observation wells. Each of these wells has approximately 200 feet of open borehole below the water table, penetrating the E through G and I basalt flow groups and interbedded sediments of the Snake River Plain aquifer. The success of the aquifer tests was limited by the inability to induce measurable drawdown in several zones. Time-drawdown data from aquifer tests were matched to type curves for 8 of the 16 zones tested. A single aquifer test at the water table exhibited greater curvature than those at depth. The increased degree of curvature suggests an unconfined response and resulted in an estimate of specific yield of 0.03. Aquifer tests below the water table generally yielded time-drawdown graphs with a rapid initial response followed by constant drawdown throughout the duration of the tests; up to several hours in length. The rapid initial response implies that the aquifer responds as a confined system during brief pumping periods. The nearly constant drawdown suggests a secondary source of water, probably vertical flow from overlying and underlying aquifer layers. Three analytical models were applied for comparison to the conceptual model and to provide estimates of aquifer properties. This, Hantush-Jacob leaky aquifer, and the Moench double-porosity fractured rock models were fit to time-drawdown data. The leaky aquifer type curves of Hantush and Jacob generally provided the best match to observed drawdown. A specific capacity regression equation was also used to estimate hydraulic conductivity.

  8. Trace elemental analysis of school chalk using energy dispersive X-ray florescence spectroscopy (ED-XRF)

    Science.gov (United States)

    Maruthi, Y. A.; Das, N. Lakshmana; Ramprasad, S.; Ram, S. S.; Sudarshan, M.

    2015-08-01

    The present studies focus the quantitative analysis of elements in school chalk to ensure the safety of its use. The elements like Calcium (Ca), Aluminum (Al), Iron (Fe), Silicon (Si) and Chromium (Cr) were analyzed from settled chalk dust samples collected from five classrooms (CD-1) and also from another set of unused chalk samples collected from local market (CD-2) using Energy Dispersive X-Ray florescence(ED-XRF) spectroscopy. Presence of these elements in significant concentrations in school chalk confirmed that, it is an irritant and occupational hazard. It is suggested to use protective equipments like filtered mask for mouth, nose and chalk holders. This study also suggested using the advanced mode of techniques like Digital boards, marker boards and power point presentations to mitigate the occupational hazard for classroom chalk

  9. Trace elemental analysis of school chalk using energy dispersive X-ray florescence spectroscopy (ED-XRF)

    International Nuclear Information System (INIS)

    The present studies focus the quantitative analysis of elements in school chalk to ensure the safety of its use. The elements like Calcium (Ca), Aluminum (Al), Iron (Fe), Silicon (Si) and Chromium (Cr) were analyzed from settled chalk dust samples collected from five classrooms (CD-1) and also from another set of unused chalk samples collected from local market (CD-2) using Energy Dispersive X-Ray florescence(ED-XRF) spectroscopy. Presence of these elements in significant concentrations in school chalk confirmed that, it is an irritant and occupational hazard. It is suggested to use protective equipments like filtered mask for mouth, nose and chalk holders. This study also suggested using the advanced mode of techniques like Digital boards, marker boards and power point presentations to mitigate the occupational hazard for classroom chalk

  10. Trace elemental analysis of school chalk using energy dispersive X-ray florescence spectroscopy (ED-XRF)

    Energy Technology Data Exchange (ETDEWEB)

    Maruthi, Y. A., E-mail: ymjournal2014@gmail.com [Associate professor, Dept of Environmental Studies, GITAM Institute of Science, GITAM University, Visakhapatnam, A.P (India); Das, N. Lakshmana, E-mail: nldas9@gmail.com [Professor, Dept of Physics, GITAM Institute of Science, GITAM University, Visakhapatnam, A.P (India); Ramprasad, S., E-mail: ramprasadsurakala@gmail.com [Research Scholar, Dept of Environmental science, GITAM Institute of Science, GITAM University, Visakhapatnam, A.P (India); Ram, S. S., E-mail: tracebio@gmail.com [Research Scholar, Dept of Trace element research, UGC-DAE Consortium Centre, Kolkata centre India (India); Sudarshan, M., E-mail: sude@alpha.iuc.res.in [Scientist-F, Dept of Trace element research, UGC-DAE Consortium Centre, Kolkata centre India (India)

    2015-08-28

    The present studies focus the quantitative analysis of elements in school chalk to ensure the safety of its use. The elements like Calcium (Ca), Aluminum (Al), Iron (Fe), Silicon (Si) and Chromium (Cr) were analyzed from settled chalk dust samples collected from five classrooms (CD-1) and also from another set of unused chalk samples collected from local market (CD-2) using Energy Dispersive X-Ray florescence(ED-XRF) spectroscopy. Presence of these elements in significant concentrations in school chalk confirmed that, it is an irritant and occupational hazard. It is suggested to use protective equipments like filtered mask for mouth, nose and chalk holders. This study also suggested using the advanced mode of techniques like Digital boards, marker boards and power point presentations to mitigate the occupational hazard for classroom chalk.

  11. Hydrologic conditions and distribution of selected radiochemical and chemical constituents in water, Snake River Plain aquifer, Idaho National Engineering Laboratory, Idaho, 1992 through 1995

    Energy Technology Data Exchange (ETDEWEB)

    Bartholomay, R.C.; Tucker, B.J.; Ackerman, D.J.; Liszewski, M.J.

    1997-04-01

    Radiochemical and chemical wastewater discharged since 1952 to infiltration ponds and disposal wells at the Idaho National Engineering Laboratory (INEL) has affected water quality in the Snake River Plain aquifer. The US Geological Survey, in cooperation with the US Department of Energy, maintains a monitoring network at the INEL to determine hydrologic trends and to delineate the movement of radiochemical and chemical wastes in the aquifer. This report presents an analysis of water-level and water-quality data collected from the Snake River Plain aquifer during 1992--95.

  12. Hydrologic conditions and distribution of selected radiochemical and chemical constituents in water, Snake River Plain aquifer, Idaho National Engineering Laboratory, Idaho, 1992 through 1995

    International Nuclear Information System (INIS)

    Radiochemical and chemical wastewater discharged since 1952 to infiltration ponds and disposal wells at the Idaho National Engineering Laboratory (INEL) has affected water quality in the Snake River Plain aquifer. The US Geological Survey, in cooperation with the US Department of Energy, maintains a monitoring network at the INEL to determine hydrologic trends and to delineate the movement of radiochemical and chemical wastes in the aquifer. This report presents an analysis of water-level and water-quality data collected from the Snake River Plain aquifer during 1992--95

  13. Decommissioning the physics laboratory, building 777-10A, at the Savannah River Site (SRS)

    International Nuclear Information System (INIS)

    SRS recently completed a four year mission to decommission ∼250 excess facilities. As part of that effort, SRS decommissioned a 48,000 ft2 laboratory that housed four low-power test reactors, formerly used by SRS to determine reactor physics. This paper describes and reviews the decommissioning, with a focus on component segmentation and handling (i.e. hazardous material removal, demolition, and waste handling). The paper is intended to be a resource for engineers, planners, and project managers, who face similar decommissioning challenges. Building 777-10A, located at the south end of SRS's A/M-Area, was built in 1953 and had a gross area of ∼48,000 ft2. Building 777-10A had two main areas: a west wing, which housed four experimental reactors and associated equipment; and an east wing, which housed laboratories, and shops, offices. The reactors were located in two separate areas: one area housed the Process Development Pile (PDP) reactor and the Lattice Test Reactor (LTR), while the second area housed the Standard Pile (SP) and the Sub-critical Experiment (SE) reactors. The west wing had five levels: three below and three above grade (floor elevations of -37', -28', -15', 0', +13'/+16' and +27' (roof elevation of +62')), while the east wing had two levels: one below and one above grade (floor elevations of -15' and 0' (roof elevation of +16')). Below-grade exterior walls were constructed of reinforced concrete, ∼1' thick. In general, above-grade exterior walls were steel frames covered by insulation and corrugated, asbestos-cement board. The two interior walls around the PDP/LTR were reinforced concrete ∼5' thick and ∼30' high, while the SP/SE reactors resided in a reinforced, concrete cell with 3.5'-6' thick walls/roof. All other interior walls were constructed of metal studs covered with either asbestos-cement or gypsum board. In general, the floors were constructed of reinforced concrete on cast-in-place concrete beams below-grade and concrete on

  14. Attempted integration of geologic and geophysical data from the Idaho National Engineering Laboratory area, Eastern Snake River Plain

    International Nuclear Information System (INIS)

    The Eastern Snake River Plain (ESRP) is a late-Cenozoic, bimodal volcanic province that developed synchronously with basin-and-range extension in the surrounding tectonic province. Strong geologic and geophysical contrasts exist between these two provinces. The Basin and Range is composed of northwest-trending, carbonate-bedrock ranges and alluvium-filled valleys. The ESRP is a bimodal volcanic province, with Tertiary silicic-volcanic rocks overlain by Quaternary mafic lavas. Patterns of ESRP volcanism and associated dike-induced surface deformation suggest that Quaternary crustal extension on the ESRP is accommodated by intrusion of basaltic dikes along northwest-trending volcanic-rift zones. This contrasts with recurrent seismogenic slip along northwest-trending, segmented normal faults in the adjacent Basin and Range tectonic province. The authors present new geophysical compilations, and they attempt to correlate these data with the surface distribution of volcanic-rift zones and other mapped geologic features near the Idaho National Engineering Laboratory. Numerous, northwest-trending aeromagnetic anomalies do not always correspond with mapped volcanic-rift zones, which are expected to be underlain by mafic-dike swarms. Northwest-trending gravity anomalies also cross the ESRP, but their widths suggest broadly distributed masses rather than narrow rift zones. The spatial and temporal distribution of volcanic-rift zones on the ESRP has important implications for regional tectonics and seismicity, as well as the assessment of seismic- and volcanic hazards at the Idaho National Engineering Laboratory. Discrepancies among the data sets suggest that older, buried volcanic-rift zones may have existed in a different configuration than is currently indicated by surficial geology. Alternatively, the geophysical signatures of non-rift-zone features may be indistinguishable from those of volcanic-rift zones

  15. Geophysical logging studies in the Snake River Plain Aquifer at the Idaho National Engineering Laboratory: Wells 44, 45, and 46

    International Nuclear Information System (INIS)

    A geophysical logging program was undertaken to vertically profile changes in the hydrology and hydrochemistry of the Snake River Plain aquifer underlies the Idaho National Engineering Laboratory (INEL). Field investigations were concentrated within an area west of the Idaho Chemical Processing Plant (ICPP) in three wells that penetrated the upper 190 feet of the aquifer. The logs obtained in these wells consisted of temperature, caliper, nuclear (neutron porosity and gamma-gama density), natural gamma, borehole televiewer, gamma spectral, and thermal flowmeter (with and without pumping). The nuclear, caliper, and televiewer logs are used to delineate individual basalt flows or flow units and to recognize breaks between flows or flow units at interflow contact zones and sedimentary interbeds. The temperature logs and flowmeter measurements obtained under ambient hydraulic head conditions identified upward fluid-circulation patterns in the three wells. Gamma-spectral analyses performed at several depths in each well showed that the predominant source of gamma radiation in the formation at this site originates mainly from potassium (40K). However, 137Cesium was detected at 32 feet below land surface in well 45. An empirical investigation of the effect of source-receiver spacing on the response of the neutron-porosity logging tool was attempted in an effort to understand the conditions under which this tool might be applied to large-diameter boreholes in-unsaturated formations

  16. Oak Ridge National Laboratory Biological Monitoring and Abatement Program for White Oak Creek Watershed and the Clinch River

    International Nuclear Information System (INIS)

    On April 1, 1986, a National Pollutant Discharge Elimination System (NPDES) permit was issued for the Oak Ridge National Laboratory (ORNL) (EPA 1986). As specified in Part 3: Special Conditions (Item H) of the permit, a plan for biological monitoring of the Clinch River, White Oak Creek (WOC), Northwest Tributary (NWT) of WOC, Melton Branch (MB), Fifth Creek, and First Creek shall be submitted for approval to the US Environmental Protection Agency (EPA) and the Tennessee Department of Health and Environment (TDHE) within 90 days of the effective date of the permit. The plan, which is referred to in Part 3 (H) of the permit as the Biological Monitoring Plan and Abatement Program (BMPAP), describes characterization monitoring studies to be conducted for the duration of the permit (5 years). In order to be consistent with the terminology used for the Biological Monitoring and Abatement Programs for the Oak Ridge Y-12 Plan and the Oak Ridge K-25 Plant, BMPAP will subsequently be referred to as the Biological Monitoring and Abatement Program (BMAP). The proposed BMAP outlined in this document is based on preliminary discussions held on December 9, 1985, between staff of Martin Marietta Energy Systems, Inc. (ORNL and Central Management), the US Department of Energy (DOE), EPA, and TDHE. 232 refs., 11 figs., 7 tabs

  17. Oak Ridge National Laboratory Biological Monitoring and Abatement Program for White Oak Creek Watershed and the Clinch River

    Energy Technology Data Exchange (ETDEWEB)

    Loar, J.M.; Adams, S.M.; Allison, L.J.; Blaylock, B.G.; Boston, H.L.; Huston, M.A.; Kimmel, B.L.; Smith, J.G.; Southworth, G.R.; Stewart, A.J.; Walton, B.T.; Kitchings, J.T.; Olsen, C.R.

    1991-09-01

    On April 1, 1986, a National Pollutant Discharge Elimination System (NPDES) permit was issued for the Oak Ridge National Laboratory (ORNL) (EPA 1986). As specified in Part 3: Special Conditions (Item H) of the permit, a plan for biological monitoring of the Clinch River, White Oak Creek (WOC), Northwest Tributary (NWT) of WOC, Melton Branch (MB), Fifth Creek, and First Creek shall be submitted for approval to the US Environmental Protection Agency (EPA) and the Tennessee Department of Health and Environment (TDHE) within 90 days of the effective date of the permit. The plan, which is referred to in Part 3 (H) of the permit as the Biological Monitoring Plan and Abatement Program (BMPAP), describes characterization monitoring studies to be conducted for the duration of the permit (5 years). In order to be consistent with the terminology used for the Biological Monitoring and Abatement Programs for the Oak Ridge Y-12 Plan and the Oak Ridge K-25 Plant, BMPAP will subsequently be referred to as the Biological Monitoring and Abatement Program (BMAP). The proposed BMAP outlined in this document is based on preliminary discussions held on December 9, 1985, between staff of Martin Marietta Energy Systems, Inc. (ORNL and Central Management), the US Department of Energy (DOE), EPA, and TDHE. 232 refs., 11 figs., 7 tabs.

  18. Effects of the restoration mortar on chalk stone buildings

    Science.gov (United States)

    Ion, R. M.; Teodorescu, S.; Ştirbescu, R. M.; Dulamă, I. D.; Şuică-Bunghez, I. R.; Bucurică, I. A.; Fierăscu, R. C.; Fierscu, I.; Ion, M. L.

    2016-06-01

    The monument buildings as components of cultural heritage are exposed to degradation of surfaces and chemical and mechanical degradation, often associated to soiling and irreversible deterioration of the building. In many conservative and restorative works, a cement-based mortar was used without knowing all the adverse effects of this material on the building. This paper deals with the study of the effects of natural cement used in restorative works in the particular case of the Basarabi-Murfatlar Churches Ensemble. Cement-based materials exposed to sulfate present in the chalk stone - gypsum (CaSO4.2H2O), can induce signs of deterioration, due to ettringite ([Ca3Al (OH)612H2O]2(SO4)32H2O) or thaumasite (Ca3[Si(OH)612H2O](CO3)SO4) formation. These phases contribute to strain within the material, inducing expansion, strength loss, spalling and severe degradation. Several combined techniques (XRD, EDXRF, ICP-AES, SEM, EDS, sulphates content, FT-IR and Raman analysis were carried out to put into evidence the effects of them on the building walls.

  19. Experimental study and mechanical modelling of the effects of water-driving in an oil saturated chalk. Application to the petroleum industry; Etude experimentale et modelisation mecanique des effets du balayage a l'eau dans une craie saturee d'huile. Application a l'industrie petroliere

    Energy Technology Data Exchange (ETDEWEB)

    Mata, C.

    2001-01-01

    The production of hydrocarbons may sometimes lead to compaction of the oil-reservoir layers with substantial collapse of the soil surface; this mechanism is usually mentioned as Subsidence. Classical remedy to this problem is to sustain the fluid pressure with the help of water injection. However, in presence of high porosity chalk (porosity > 30%), this technique does not give effective results: the subsidence rate at North Sea reservoirs (Ekofisk field), after injection, has remained unchanged. Some justify the subsistence in the chalk as caused by phenomena of dissolution of the carbonates; others think it is connected to the destruction of capillary menisci. In this research, we follow this second approach. This study is finalized to a better understanding of the compaction mechanisms in pure carbonates when water is injected. This is done by proposing -in micro-scale first and in macro-scale after- a physical model that agrees with empirical observations. In order to meet this target, IFP skills and experience in physical and chemical measurements (taken before, after and during mechanical tests) have proficiently joined ENPC laboratory (CERMMO) knowledge of micro and macro modelling. The soft rock studied is a Paris basin's white chalk (Craie de Guerville). Its physical and chemical characterisation (i.e.: silica content, porosity, permeability) is very similar to North Sea chalk, but Guerville chalk has never been in contact with oil and generally it crops out of the ground surface. Strength parameters of this rock have been first determined by standard triaxial tests. Three different saturation configurations have been examined: dry, fully oil-saturated and fully water-saturated. As literature clearly state, dry chalk is stronger than oil saturated chalk and the first two are largely stronger than water saturated chalk. Therefore uniaxial strain water injection tests have been performed on oil saturated samples. Results, coupled with previous physical

  20. Hydrologic conditions and distribution of selected radiochemical and chemical constituents in water, Snake River Plain aquifer, Idaho National Engineering Laboratory, Idaho, 1989 through 1991

    International Nuclear Information System (INIS)

    Radiochemical and chemical wastewater discharged since 1952 to infiltration ponds and disposal wells at the Idaho National Engineering Laboratory (INEL) has affected water quality in the Snake River Plain aquifer. The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, maintains a continuous monitoring network at the INEL to determine hydrologic trends and to delineate the movement of radiochemical and chemical wastes in the aquifer. This report presents an analysis of water-level and water-quality data collected from the Snake River Plain aquifer during 1989-91. Water in the eastern Snake River Plain aquifer moves principally through fractures and interflow zones in basalt, generally flows southwestward, and eventually discharges at springs along the Snake River. The aquifer is recharged principally from irrigation water, infiltration of streamflow, and ground-water inflow from adjoining mountain drainage basins. Water levels in wells throughout the INEL generally declined during 1989-91 due to drought. Detectable concentrations of radiochemical constituents in water samples from wells in the Snake River Plain aquifer at the INEL decreased or remained constant during 1989-91. Decreased concentrations are attributed to reduced rates of radioactive-waste disposal, sorption processes, radioactive decay, and changes in waste-disposal practices. Detectable concentrations of chemical constituents in water from the Snake River Plain aquifer at the INEL were variable during 1989-91. Sodium and chloride concentrations in the southern part of the INEL increased slightly during 1989-91 because of increased waste-disposal rates and a lack of recharge from the Big Lost River. Plumes of 1,1,1-trichloroethane have developed near the Idaho Chemical Processing Plant and the Radioactive Waste Management Complex as a result of waste disposal practices

  1. Inventory of site-derived 36Cl in the Snake River plain aquifier, Idaho National Engineering Laboratory, Idaho

    International Nuclear Information System (INIS)

    Radioactive waste management practices at the U.S. Department of Energy's Idaho National Engineering Laboratory (INEL) in Idaho have introduced 36Cl (T1/2 = 301,000 yr) into the Snake River Plain aquifer underlying the site. The 36Cl is believed to originate from neutron activation of stable 35Cl in nuclear fuels (principally) and in reactor cooling/process water. Wastewater releases of 3H at the INEL have been documented by the site operators for the period 1952 to 1988. During this time, approximately 1.2 PBq of 3H (30,000 Ci) were introduced to the subsurface through disposal wells and seepage ponds. By sampling a number of monitoring and production wells downgradient from points of introduction, 3H movement and dispersion in the groundwater have been documented by the U.S. Geological Survey. The present report uses these historical 3H release and monitoring data to choose hydrologic parameters (matrix porosity and plume penetration depth) that produce concordance between the 3H release estimates and the inventory calculated from measurements of 3H in the subsurface. These parameters are then applied to 36Cl isopleths to generate an estimated 36Cl inventory in the subsurface. Using assumptions about irradiation times, neutron fluxes, and total fuel processed, as little as 23 g of stable chloride impurity in fuel elements would be adequate to produce the amount of 36Cl estimated to be in the groundwaters underlying the site. The highest atom concentration of 36Cl measured onsite (222x1010 atoms 1-1) corresponds to an activity level of ∼4 pCi 1-1 and represents 0.2 percent of the U.S. Environmental Protection Agency's (EPA) drinking water standard for this radionuclide (2000 pCi 1-1)

  2. Mineralogy and depositional sources of sedimentary interbeds beneath the Idaho National Engineering Laboratory; eastern Snake River Plain, Idaho

    International Nuclear Information System (INIS)

    Idaho State University, in cooperation with the U.S. Geological Survey, and the U.S. Department of Energy, collected 57 samples of sedimentary interbeds at 19 sites at the Idaho National Engineering Laboratory (INEL) for mineralogical analysis. Previous work by the U.S. Geological Survey on surficial sediments showed that ratios detrital of quartz, total feldspars, and calcite can be used to distinguish the sedimentary mineralogy of specific stream drainages at the INEL. Semi-quantitative x-ray diffraction analyses were used to determine mineral abundances in the sedimentary interbeds. Samples were collected from wells at the New Production Reactor (NPR) area, Idaho Chemical Processing Plant (ICPP), Test Reactor Area (TRA), miscellaneous sites, Radioactive Waste Management Complex (RWMC), Naval Reactors Facility (NRF), and Test Area North (TAN). Normalized mean percentages of quartz, feldspar, and carbonate were calculated from sample data sets at each site. Percentages for quartz, feldspar, and carbonate from the NPR, ICPP, TRA, miscellaneous sites, RWMC, and NRF ranged from 37 to 59, 26 to 40, and 5 to 25, respectively. Percentages for quartz, feldspar, and carbonate from wells at Test Area North (TAN) were 24, 10, and 66, respectively. Mineralogical data indicate that sedimentary interbed samples collected from the NPR, ICPP, TRA, miscellaneous sites, RWMC, and NRF correlate with surficial sediment samples from the present day Big Lost River. Sedimentary interbeds from TAN sites correlate with surficial sediment samples from Birch Creek. These correlations suggest that the sources for the sediments at and near the INEL have remained relatively consistent for the last 580,000 years. 12 refs., 4 figs., 3 tabs

  3. Managing Injected Water Composition To Improve Oil Recovery: A Case Study of North Sea Chalk Reservoirs

    DEFF Research Database (Denmark)

    Zahid, Adeel; Shapiro, Alexander; Stenby, Erling Halfdan;

    2012-01-01

    with the following injecting fluids: distilled water, brine with and without sulfate, and brine containing only magnesium ions. The total oil recovery, recovery rate, and interaction mechanisms of ions with rock were studied for different injecting fluids at different temperatures and wettability...... only the injection brine composition but also the formation water composition affected the oil recovery at high temperatures from the Stevns Klint chalk rock.......In recent years, many core displacement experiments of oil by seawater performed on chalk rock samples have reported SO42–, Ca2+, and Mg2+ as potential determining ions for improving oil recovery. Most of these studies were carried out with outcrop chalk core plugs. The objective of this study is...

  4. Full-waveform Inversion of Crosshole GPR Data Collected in Strongly Heterogeneous Chalk

    DEFF Research Database (Denmark)

    Keskinen, Johanna; Zibar, Majken Caroline Looms; Nielsen, Lars;

    2015-01-01

    in an old chalk quarry in Eastern Denmark. Based on core data (including plug samples and televiewer logging data) collected in our four ~15-m-deep boreholes and results from previous related studies, it is apparent that the studied chalk is strongly heterogeneous. The upper ~7 m consist of variable coarse...... all the information contained in the data and is able to provide significantly improved images. Here, we apply full-waveform inversion to crosshole GPR data to image strong heterogeneity of the chalk related to changes in lithology and porosity. We have collected a crosshole tomography dataset...... address the importance of (i) adequate starting models, both in terms of the dielectric permittivity and the electrical conductivity, (ii) the estimation of the source wavelet, (iii) and the effects of data sampling density when imaging this rock type. Moreover, we discuss the resolution of the bedding...

  5. Streamflow losses and ground-water level changes along the Big Lost River at the Idaho National Engineering Laboratory, Idaho

    International Nuclear Information System (INIS)

    The Big Lost flows onto the eastern Snake River Plain near Arco, Idaho, and across the INEL. Stream-flow recharges the Snake River Plain aquifer from the Big Lost River channel, the INEL spreading areas, and playas at the river terminus. Average annual streamflow for the Big Lost River from 1965 to 1987 above the INEL diversion was 104,436 acre-ft; about 50% of this flow was diverted to the INEL spreading areas, about 9% infiltrated between the INEL diversion and Lincoln Boulevard, and the remainder infiltrated below Lincoln Boulevard or flowed into playas. Streamflow losses to evapotranspiration were minor compared to infiltration losses. Infiltration loss was estimated along the 44 river miles from Arco to playa 1 at discharges ranging from 37 to 372 cu ft/sec. At discharges less than 100 cu ft/sec, loss from Arco to the Big Lost River Sinks was 1 to 4 cu ft/sec/mile. Loss from the sinks to playa 1 ranged from 7 to 12 cu ft/sec/mile. Infiltration loss was greatest at large discharges. At a discharge of 372 cu ft/sec, a loss of 28 cu ft/sec/mi was estimated in the area of the Big Lost River is substantial immediately southwest of the Radioactive Waste Management Complex and in the area form the Naval Reactor Facility to playas 1 and 2

  6. Correlation of carbon isotope events in the Danish Upper Cretaceous chalk

    Energy Technology Data Exchange (ETDEWEB)

    Schovsbo, N.H.; Rasmussen, Susanne L.; Sheldon, E. (Geological Survey of Denmark and Greenland, Copenhagen (Denmark)); Stemmerik, L. (Univ. of Copenhagen, Dept. of Geography and Geology, Copenhagen (Denmark))

    2008-07-15

    A high resolution carbon isotope (delta13C) profile through the upper Campanian to Maastrichtian chalk was recently completed based on material from the Stevns-1 core from the Stevns peninsula, eastern Denmark. The delta13C variation of marine carbonates essentially reflects global perturbations in the carbon cycle, i.e. the burial fluxes of carbonate carbon versus organic carbon. It is widely observed that the delta13C variation broadly tracks the eustatic sea-level curve, and that delta13C curves can be used for stratigraphic correlation. In the Stevns-1 core, a total of 29 notable isotope changes have been identified in the upper Campanian to Maastrichtian succession. In order to evaluate the stratigraphic significance of the isotope changes, the variation in delta13C values of the mid-Maastrichtian chalk from cores in eastern Denmark and the Danish North Sea, and from outcrops at Roerdal, northern Jylland has been examined. The selected interval is characterised by distinct chalk and marl cycles in the Stevns-1 and Karlslunde-1 cores and in the Roerdal quarry, where as a non-cyclic clean chalk is found in the M-10X well from the North Sea. In the Roerdal quarry, the chalk-marl unit spans the upper-lower Maastrichtian boundary in the Boreal brachiopod and belemnite stratigraphies. In Stevns-1 and Karlslunde-1 the chalk-marl unit was deposited during the younger part of nannofossil subzone UC20b. This paper presents preliminary results of a high-resolution study of carbon isotopes, carried out by the Geological Survey of Denmark and Greenland (GEUS) in co-operation with partners from the Department of Geography and Geology at the University of Copenhagen. This paper is a product of the Cretaceous Research Centre (CRC) at Geocenter Denmark. (au)

  7. Change of Static and Dynamic Elastic Properties due to CO² Injection in North Sea Chalk

    DEFF Research Database (Denmark)

    Alam, Mohammad Monzurul; Hjuler, M.L.; Christensen, H.F.;

    2012-01-01

    % non-carbonate. We studied difference in static and dynamic behavior. Furthermore, brine saturated data were compared with CO2 injected data to reveal the effect of supercritical CO2 injection in both static and dynamic elastic properties. We used strain gauges and LVDTs to measure static deformation....... We observed lower dynamic elastic modulus for chalk with higher non-carbonate content at porosities lower than 30%. In 30% porosity chalk, dynamic compressional and bulk modulus were found significantly higher than the static modulus. Static measurements with LVDT were found lowest. The effect of CO2...

  8. Hydrologic Conditions and Distribution of Selected Constituents in Water, Snake River Plain Aquifer, Idaho National Engineering and Environmental Laboratory, Idaho, 1996 through 1998

    Energy Technology Data Exchange (ETDEWEB)

    R. C. Bartholomay; B. J. Tucker; L. C. Davis; M. R. Greene

    2000-09-01

    Radiochemical and chemical wastewater discharged since 1952 to infiltration ponds and disposal wells at the Idaho National Engineering and Environmental Laboratory (INEEL) has affected water quality in the Snake River Plain aquifer. The US Geological Survey, in cooperation with the US Department of Energy, maintains a monitoring network at the INEEL to determine hydrologic trends and to delineate the movement to radiochemical and chemical wastes in the aquifer. This report presents an analysis of water-level and water-quality data collected from the Snake River Plain aquifer during 1996-98. Detectable concentrations of radiochemical constituents in water samples from wells in the Snake River Plain aquifer at the INEEL decreased or remained constant during 1996-98. Decreased concentrations are attributed to reduced rates of radioactive-waste disposal, sorption process, radioactive decay, and changes in waste-disposal practices. Detectable concentrations of chemical constituents in water from the Snake River Plain aquifer at the INEEL were variable during 1996-98.

  9. Factors controlling radiocesium distribution in river sediments: Field and laboratory studies after the Fukushima Dai-ichi Nuclear Power Plant accident

    International Nuclear Information System (INIS)

    Highlights: • Kd of 137Cs were not only related to particle size but also to clay mineral content. • 137Cs can be extracted from sediments in water when salinity becomes high. • RCs in sediments will be equilibrated with stable Cs during its transportation. - Abstract: This study used laboratorial estimations and determined the distribution coefficient (Kd) of 137Cs in river sediments sampled from the Abukuma River and the Kuchibuto River to investigate the particle size dependence of RCs distribution. Results show that the Kd patterns of 137Cs (particle size-dependence of Kd) were not only related to the particle size of large particles (low clay mineral content) but also to the clay mineral content of small particles (high clay mineral content) and particularly cation concentration in aqueous phase. By contrast, the Kd patterns of stable Cs (133Cs) exhibited no obvious particle size dependence. Adsorption species of Cs that was added to the river sediments at various particle sizes was almost the same at the molecular scale as determined by the extended X-ray absorption fine structure. Our findings indicate that river sediments have high fixation ability to 137Cs. Nevertheless, adsorbed 137Cs can be extracted from sediments in the water phase when salinity becomes high, such as that in seawater. The distribution patterns of 137Cs at various particle sizes can slowly down the equilibrium of the adsorption of 137Cs during the transportation of river sediments, and then the behavior of 137Cs should eventually be similar to that of stable Cs in the river system. Therefore, the particle size of sediments is an important factor in the distribution of RCs at the early stage of its deposition. In the end, RCs adsorbed on the sediments will be equilibrated with the stable Cs during its transportation in the river system. Controlling factors such as the mineralogy of sediments could possibly make the distribution patterns of RCs similar to that of stable Cs in the

  10. 226Ra and 210Pb lixiviation sediments from the region of uranium mine and mill in Pocos de Caldas, contaminated in laboratory by river water and chemical agents, mobility and availability in soils

    International Nuclear Information System (INIS)

    Leaching experiments of river bottom sediments, contaminated in the laboratory with 226Ra or 210Pb, by river waters or solutions of inorganic salts and mobility experiments of these radionuclides added to soil columns and leached by a volume of distilled or river water, equivalent to the average annual rain precipitation in the region, are performed. The determination of 226Ra and 210Pb exchangeable fractions in soils contaminated in the laboratory are studied too. The results, as a whole, lead to the conclusion that 226Ra should be considered, potentially, the radionuclide most able to increase the population radiation dose, through the ingestion of contaminated water and foodstuff. (M.A.C.)

  11. Second report on the Oak Ridge National Laboratory Biological Monitoring and Abatement Program for White Oak Creek Watershed and the Clinch River

    International Nuclear Information System (INIS)

    As a condition of the National Pollutant Discharge Elimination System (NPDES) permit issued to Oak Ridge National Laboratory (ORNL) on April 1, 1986, a Biological Monitoring and Abatement Program (BMAP) was developed for White Oak Creek (WOC); selected tributaries of WOC, including Fifth Creek, First Creek, Melton Branch, and Northwest Tributary; and the Clinch River. BMAP consists of seven major tasks that address both radiological and nonradiological contaminants in the aquatic and terrestrial environs on-site and the aquatic environs off-site. These tasks are (1) toxicity monitoring; (2) bioaccumulation monitoring of nonradiological contaminants in aquatic biota; (3) biological indicator studies; (4) instream ecological monitoring; (5) assessment of contaminants in the terrestrial environment; (6) radioecology of WOC and White Oak Lake (WOL); and (7) contaminant transport, distribution, and fate in the WOC embayment-Clinch River-Watts Bar Reservoir system. This document, the second of a series of annual reports, described the results of BMAP studies conducted in 1987

  12. Second report on the Oak Ridge National Laboratory Biological Monitoring and Abatement Program for White Oak Creek Watershed and the Clinch River

    Energy Technology Data Exchange (ETDEWEB)

    Loar, J.M. [ed.; Adams, S.M.; Bailey, R.D.; Blaylock, B.G.; Boston, H.L.; Cox, D.K.; Huston, M.A.; Kimmel, B.L.; Loar, J.M.; Olsen, C.R.; Ryon, M.G.; Shugart, L.R.; Smith, J.G.; Southworth, G.R.; Stewart, A.J.; Walton, B.T.; Talmage, S.S.; Murphy, J.B.; Valentine, C.K. [Oak Ridge National Lab., TN (United States); Appellanis, S.M.; Jimenez, B.D. [Puerto Rico Univ., San Juan (Puerto Rico); Huq, M.V. [Connecticut Dept. of Environmental Protection, Hamden, CT (United States); Meyers-Schone, L.J. [Frankfurter, Gross-Gerau (Germany); Mohrbacher, D.A. [Automated Sciences Group, Inc., Oak Ridge, TN (United States); Olsen, C.R. [USDOE Office of Energy Research, Washington, DC (United States). Environmental Sciences Div.; Stout, J.G. [Cincinnati Univ., OH (United States)

    1992-12-01

    As a condition of the National Pollutant Discharge Elimination System (NPDES) permit issued to Oak Ridge National Laboratory (ORNL) on April 1, 1986, a Biological Monitoring and Abatement Program (BMAP) was developed for White Oak Creek (WOC); selected tributaries of WOC, including Fifth Creek, First Creek, Melton Branch, and Northwest Tributary; and the Clinch River. BMAP consists of seven major tasks that address both radiological and nonradiological contaminants in the aquatic and terrestrial environs on-site and the aquatic environs off-site. These tasks are (1) toxicity monitoring; (2) bioaccumulation monitoring of nonradiological contaminants in aquatic biota; (3) biological indicator studies; (4) instream ecological monitoring; (5) assessment of contaminants in the terrestrial environment; (6) radioecology of WOC and White Oak Lake (WOL); and (7) contaminant transport, distribution, and fate in the WOC embayment-Clinch River-Watts Bar Reservoir system. This document, the second of a series of annual reports, described the results of BMAP studies conducted in 1987.

  13. Strength and Biot's coefficient for high-porosity oil- or water-saturated chalk

    DEFF Research Database (Denmark)

    Andreassen, Katrine Alling

    during hydrostatic loading. The hypothesis is that the Biot coefficient and the theory of poroelasticity may cover the fluid effect by including the increased fluid bulk modulus from oil to water. A high number of test results for both oil- and water-saturated high-porosity outcrop chalk show correlation...

  14. Ultrasonic velocities of North Sea chalk samples: influence of porosity, fluid content and texture

    DEFF Research Database (Denmark)

    Rogen, B.; Fabricius, Ida Lykke; Japsen, P.; Høier, Camilla Kruse; Mavko, G.; Pedersen, J.M.

    2005-01-01

    the South Arne Field than from the Dan Field for identical porosities. This difference may be due to textural differences between the chalk at the two locations because we observe that large grains (i.e. filled microfossils and fossil fragments) that occur more frequently in samples from the Dan Field...

  15. Nuclear magnetic resonance and sound velocity measurements of chalk saturated with magnesium rich brine

    DEFF Research Database (Denmark)

    Katika, Konstantina; Alam, Mohammad Monzurul; Fabricius, Ida Lykke

    The use of low field Nuclear Magnetic Resonance (NMR) to determine petrophysical properties of reservoirs has proved to be a good technique. Together with sonic and electrical resistivity measurements, NMR can contribute to illustrate the changes on chalk elasticity due to different pore water...

  16. The surface reactivity of chalk (biogenic calcite) with hydrophilic and hydrophobic functional groups

    Science.gov (United States)

    Okhrimenko, D. V.; Dalby, K. N.; Skovbjerg, L. L.; Bovet, N.; Christensen, J. H.; Stipp, S. L. S.

    2014-03-01

    The surface properties of calcium carbonate minerals play an important role in a number of industrial and biological processes. Properties such as wettability and adsorption control liquid-solid interface behaviour and thus have a strong influence on processes such as biomineralisation, remediation of aquifers and oil recovery. We investigated how two model molecules of different polarity, namely water and ethanol, interact with reservoir and outcrop chalk samples and we compared their behaviour with that of pure, inorganically precipitated calcite. Thermodynamic quantities, such as the work of wetting, surface energy and isosteric adsorption enthalpy, were determined from vapour adsorption isotherms. The chalks were studied fresh and after extraction of organic residues that were originally present in these samples. The work of wetting correlates with the amount of organic matter present in the chalk samples but we observed a fundamental difference between the adsorption properties of chalk and pure, inorganically precipitated calcite toward the less polar, ethanol molecule. Further analysis of the chemical composition of the organic matter extracted from the chalk samples was made by gas chromatography (GC-MS). Monitoring surface composition by X-ray photoelectron spectroscopy (XPS) before and after extraction of the organic material, and with atomic force microscopy (AFM), showed that nanometer sized clay crystals observed on the chalk particle surfaces could be an important part of the reason for the differences. Removal of the extractable portion of the hydrocarbons liberates adsorption sites that have different wetting properties than the rest of the chalk and these have an energy distribution that is similar to clays. Thus, the results exemplify the complexity of biogenic calcite adsorption behaviour and demonstrate that chalk wetting in drinking water aquifers as well as oil reservoirs is controlled partly by the nanoparticles of clay that have grown on the

  17. Seismic stratigraphy and sedimentary architecture of the Chalk Group in south-west Denmark

    DEFF Research Database (Denmark)

    Larsen, Connie; Ineson, Jon; Boldreel, Lars Ole

    2014-01-01

    The article focuses on a study undertaken by the Chalk Group on the western onshore region of the Danish Basin in Eastern Denmark related on the seismic stratigraphy and sedimentary architecture of the region. The study is undertaken through subdividing the northern North German Basin and the south...

  18. SNG-log in borehole P7 in Faxe Chalk Quarry

    DEFF Research Database (Denmark)

    Korsbech, Uffe C C

    1996-01-01

    A spectral natural gamma-ray log in a 190 m borehole in Faxe chalk quarry confirms that Danish bryozoan and corallic limestones contain very low levels of natural radioactivity. Due to the low content of natural radioactivity it has been possible to observe the influence from cosmic radiation. The...

  19. Nuclear Magnetic Resonance and Elastic Wave Velocity of Chalk Saturated with Brines Containing Divalent Ions

    DEFF Research Database (Denmark)

    Katika, Konstantina; Alam, Mohammad Monzurul; Fabricius, Ida Lykke

    Nuclear magnetic resonance (NMR) has proven a good technique for measuring pore size distribution in reservoir rocks. The use of low field NMR together with sonic and electrical resistivity measurements, can contribute to illustrate the effect of adsorbing ions on chalk elasticity. NMR is useful...

  20. Nuclear magnetic resonance and sound velocity measurements of chalk saturated with magnesium rich brine

    DEFF Research Database (Denmark)

    Katika, Konstantina; Alam, Mohammad Monzurul; Fabricius, Ida Lykke

    2013-01-01

    The use of low field Nuclear Magnetic Resonance (NMR) to determine petrophysical properties of reservoirs has proved to be a good technique. Together with sonic and electrical resistivity measurements, NMR can contribute to illustrate the changes on chalk elasticity due to different pore water...

  1. Using Raman spectroscopic imaging for non-destructive analysis of filler distribution in chalk filled polypropylene

    DEFF Research Database (Denmark)

    Boros, Evelin; Porse, Peter Bak; Nielsen, Inga;

    2016-01-01

    A feasibility study on using Raman spectral imaging for visualization and analysis of filler distribution in chalk filled poly-propylene samples has been carried out. The spectral images were acquired using a Raman spectrometer with 785 nm light source.Eight injection-molded samples with...

  2. How burial diagenesis of chalk sediments controls sonic velocity and porosity

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke

    2003-01-01

    , whereby IF increases and chalk forms. Rock mechanical tests show that when compaction requires more than in-situ stress, porosity reduction is arrested. During subsequent burial, crystals and pores grow in size as a consequence of the continuing recrystallization. ne lack of porosity loss during...

  3. Effective-stress-law behavior of Austin chalk rocks for deformation and fracture conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Warpinski, N.R.; Teufel, L.W.

    1994-08-01

    Austin chalk core has been tested to determine the effective law for deformation of the matrix material and the stress-sensitive conductivity of the natural fractures. For deformation behavior, two samples provided data on the variations of the poroelastic parameter, {alpha}, for Austin chalk, giving values around 0.4. The effective-stress-law behavior of a Saratoga limestone sample was also measured for the purpose of obtaining a comparison with a somewhat more porous carbonate rock. {alpha} for this rock was found to be near 0.9. The low {alpha} for the Austin chalk suggests that stresses in the reservoir, or around the wellbore, will not change much with changes in pore pressure, as the contribution of the fluid pressure is small. Three natural fractures from the Austin chalk were tested, but two of the fractures were very tight and probably do not contribute much to production. The third sample was highly conductive and showed some stress sensitivity with a factor of three reduction in conductivity over a net stress increase of 3000 psi. Natural fractures also showed a propensity for permanent damage when net stressed exceeded about 3000 psi. This damage was irreversible and significantly affected conductivity. {alpha} was difficult to determine and most tests were inconclusive, although the results from one sample suggested that {alpha} was near unity.

  4. Investigation of spore forming bacterial flooding for enhanced oil recovery in a North Sea chalk Reservoir

    DEFF Research Database (Denmark)

    Halim, Amalia Yunita; Nielsen, Sidsel Marie; Eliasson Lantz, Anna;

    2015-01-01

    Little has been done to study microbial enhanced oil recovery (MEOR) in chalk reservoirs. The present study focuses on core flooding experiments designed to see microbial plugging and its effect on oil recovery. A pressure tapped core holder was used for this purpose. A spore forming bacteria Bac...

  5. Probing the intrinsically oil-wet surfaces of pores in North Sea chalk at subpore resolution

    DEFF Research Database (Denmark)

    Hassenkam, Tue; Skovbjerg, Lone Lindbæk; Stipp, Susan Louise Svane

    2009-01-01

    of the controlling factors for the effectiveness of water flooding, one of the most common methods to improve oil recovery in Chalk reservoirs. Understanding surface wetting and its variability at scales smaller than the pore dimension will potentially provide clues for more effective oil production...

  6. Uranium series geochemistry in aquifers: quantification of transport mechanisms of uranium and daughter products: the chalk aquifer (Champagne, France)

    International Nuclear Information System (INIS)

    With the increase of contaminant flux of radionuclides in surface environment (soil, river, aquifer...), there is a need to understand and model the processes that control the distribution of uranium and its daughter products during transport within aquifers. We have used U-series disequilibria as an analogue for the transport of uranium and its daughter products in aquifer to understand such mechanisms. The measurements of uranium (234U et 238U), thorium (230Th et 232Th), 226Ra and 222Rn isotopes in the solid and liquid phases of the chalk aquifer in Champagne (East of France) allows us to understand the processes responsible for fractionation within the uranium decay chain. Fractionations are induced by physical and chemical properties of the elements (leaching, adsorption) but also by radioactive properties (recoil effect during α-decay). For the first time a comprehensive sampling of the solid phase has been performed, allowing quantifying mechanisms responsible for the long term evolution of the aquifer. A non steady state 1D model has been developed which takes into account leaching, adsorption processes as well as radioactive filiation and α-recoil effect. Retardation coefficients have been calculated for uranium, thorium and radium. The aquifer is characterised by a double porosity, and the contribution of fracture and matrix porosity on the water/rock interaction processes has been estimated. (author)

  7. Late Maastrichtian chalk mounds, Stevns Klint, Denmark — Combined physical and biogenic structures

    Science.gov (United States)

    Anderskouv, Kresten; Damholt, Tove; Surlyk, Finn

    2007-08-01

    Upper Maastrichtian chalk exposed at the Sigerslev quarry, Stevns Klint, Denmark is characterized by wavy and mound-like bedding geometries outlined by bands of black flint nodules. Four morphological elements are recognized, although bedding geometries are highly variable: southward migrating mounds, eastward migrating mounds, chalk waves and evenly bedded chalk. The mounds are interpreted as having been formed by currents carrying fine-grained suspended sediment which was primarily deposited on the up-current mound flanks. Bryozoans were prolific on the up-current flanks and mound summits, which stabilized the mounds, increased bed roughness and the overall accumulation rate. However, accumulation thicknesses do not correlate consistently with bryozoan density. The bryozoans were therefore important for the formation of the mounds, but the distribution of bryozoans did not solely determine depositional thickness across a mound and thus mound growth pattern. Relatively long wavelength wavy-bedded chalk show gentle convex-up geometries and would probably be described as sediment waves if recognized in seismic sections. The chalk waves were deposited under weaker current velocities than those active during mound formation. The exposed succession is topped by more evenly bedded chalk which was deposited by quiet pelagic fall-out of fine-grained material. The whole succession was deposited on the upper part of the northern flank of a large WNW-ESE trending 3 km wide depositional ridge with an amplitude of 35-40 m formed by contour-parallel WNW-ward flowing bottom currents. The mounds may have been deposited by regional bottom currents, or by spill-over currents from the valley south of the large ridge. The succession was deposited during varying bottom current intensities and the depositional architecture indicates a complex and dynamic environment. The depositional style seems to be controlled by the interplay and relative importance of two end-member processes

  8. Worldwide Open Proficiency Test for X Ray Fluorescence Laboratories PTXRFIAEA09: Determination of Major, Minor and Trace Elements in a River Clay

    International Nuclear Information System (INIS)

    This publication presents the results of the worldwide proficiency test PTXRFIAEA09 on the determination of major, minor and trace elements in river clay. Methodologies, a data evaluation approach, a summary evaluation of each element and individual evaluation reports for each laboratory are also described. The test was carried out within the IAEA project Nuclear Spectrometry for Analytical Applications, under the Nuclear Science Programme. The main objective of the project was to enhance the capability of interest Member States in effective utilization of nuclear spectrometries and analytical services in industry, human health and agriculture, and in monitoring and evaluating environmental pollution

  9. Benthic macrofauna variations and community structure in Cenomanian cyclic chalk-marl from Southerham Grey Pit, SE England

    DEFF Research Database (Denmark)

    Lauridsen, Bodil Wesenberg; Gale, A. S.; Surlyk, Finn

    2009-01-01

    . The material comprises washing residues of 24 bulk samples collected from chalk and marl half-cycles. A total of 5055 invertebrate specimens were retrieved and referred to 68 species, forming the basis for the recognition of six guilds. In general, the fauna is more diverse in marl than in chalk, but...... clearly well adapted to both facies and thus to the fine grain size of the substrate rather than to lithology. The systematic difference in diversity between chalk and marl samples was possibly caused by long-term climatic and oceanographic changes and thus could represent a biological response to...

  10. Influence of clay and silica on permeability and capillary entry pressure of chalk reservoirs in the North Sea

    DEFF Research Database (Denmark)

    Røgen, Birte; Fabricius, Ida Lykke

    2002-01-01

    The permeability and capillary entry pressure of chalk reservoirs are controlled by their porosity and specific surface area. Measured permeabilities are in the range 0.025-5.3 mD and are successfully predicted by use of the Kozeny equation. In this paper we focus on the factors that control...... specific surface area. Fifty-nine Tor and Ekofisk Formation chalk samples from five North Sea chalk reservoirs were investigated. All contain quartz and clay minerals, most commonly kaolinite and smectite, with trace amounts of illite. The contents of calcite and quartz are inversely correlated and both...

  11. Porosity and sonic velocity depth trends of Eocene chalk in Atlantic Ocean: Influence of effective stress and temperature

    DEFF Research Database (Denmark)

    Awedalkarim, Ahmed; Fabricius, Ida Lykke

    2014-01-01

    We aimed to relate changes in porosity and sonic velocity data, measured on water-saturated Eocene chalks from 36 Ocean Drilling Program drill sites in the Atlantic Ocean, to vertical effective stress and thermal maturity. We considered only chalk of Eocene age to avoid possible influence of...... geological age on chalk compaction trends. For each depth, vertical effective stresses as defined by Terzaghi and by Biot were calculated. We used bottom-hole temperature data to calculate the time–temperature index of thermal maturity (TTI) as defined by Lopatin. Porosity and compressional wave velocity...

  12. Third report on the Oak Ridge National Laboratory Biological Monitoring and Abatement Program for White Oak Creek Watershed and the Clinch River

    International Nuclear Information System (INIS)

    As a condition of the National Pollutant Discharge Elimination System (NPDES) permit issued to Oak Ridge National Laboratory (ORNL) on April 1, 1985, a Biological Monitoring and Abatement Program (BMAP) was developed for White Oak Creek (WOC); selected tributaries of WOC, including Fifth Creek, First Creek, Melton Branch, and Northwest Tributary; and the Clinch River. The BMAP currently consists of six major tasks that address both radiological and nonradiological contaminants in the aquatic and terrestrial environs at ORNL. These are (1) toxicity monitoring, (2) bioaccumulation monitoring of nonradiological contaminants in aquatic biota, (3) biological indicator studies, (4) instream ecological monitoring, (5) assessment of contaminants in the terrestrial environment, and (6) radioecology of WOC and White Oak Lake (WOL). The investigation of contaminant transport, distribution, and fate in the WOC embayment-Clinch River-Watts Bar Reservoir system was originally a task of the BMAP but, in 1988, was incorporated into the Resource Conservation and Recovery Act Facility Investigation for the Clinch River, a separate study to assess offsite contamination from all three Department of Energy facilities in Oak Ridge

  13. Third report on the Oak Ridge National Laboratory Biological Monitoring and Abatement Program for White Oak Creek Watershed and the Clinch River

    Energy Technology Data Exchange (ETDEWEB)

    Loar, J.M. [ed.; Adams, S.M.; Bailey, R.D. [and others

    1994-03-01

    As a condition of the National Pollutant Discharge Elimination System (NPDES) permit issued to Oak Ridge National Laboratory (ORNL) on April 1, 1985, a Biological Monitoring and Abatement Program (BMAP) was developed for White Oak Creek (WOC); selected tributaries of WOC, including Fifth Creek, First Creek, Melton Branch, and Northwest Tributary; and the Clinch River. The BMAP currently consists of six major tasks that address both radiological and nonradiological contaminants in the aquatic and terrestrial environs at ORNL. These are (1) toxicity monitoring, (2) bioaccumulation monitoring of nonradiological contaminants in aquatic biota, (3) biological indicator studies, (4) instream ecological monitoring, (5) assessment of contaminants in the terrestrial environment, and (6) radioecology of WOC and White Oak Lake (WOL). The investigation of contaminant transport, distribution, and fate in the WOC embayment-Clinch River-Watts Bar Reservoir system was originally a task of the BMAP but, in 1988, was incorporated into the Resource Conservation and Recovery Act Facility Investigation for the Clinch River, a separate study to assess offsite contamination from all three Department of Energy facilities in Oak Ridge.

  14. Updated follow-up of long-term Chalk River employees

    International Nuclear Information System (INIS)

    Data on the follow-up of CRNL employees who died during employment or after retirement have been updated to 1982 December 31. Updated tables on mortality for AECL participants in the 1953 NRX clean-up and in the 1958 NRU decontamination are also included in this report. Preliminary mortality data on two other groups are presented here for (a) female employees of CRNL, 1966-1982 and (b) male employees of CRNL who have accumulated lifetime occupational doses of 0.2 Sv (20 rem) or more. Data on types of fatal cancer recorded for long-term male CRNL employees over the period 1966-1982 are also given. No statistically significant increases in cancer deaths were found in any of the groups analyzed

  15. Summary of loops in the Chalk River NRX and NRU reactors

    International Nuclear Information System (INIS)

    The design and operating parameters of the high pressure, high temperature light water loops in the NRX and NRU reactors are presented to assist experimenters reviewing these facilities for their experiments. The NRX and NRU reactor design and operating data of interest to the experimenters are also presented. (author)

  16. Radiochemistry Lab Decommissioning and Dismantlement. AECL, Chalk River Labs, Ontario, Canada

    International Nuclear Information System (INIS)

    Atomic Energy of Canada (AECL) was originally founded in the mid 1940's to perform research in radiation and nuclear areas under the Canadian Defense Department. In the mid 50's The Canadian government embarked on several research and development programs for the development of the Candu Reactor. AECL was initially built as a temporary site and is now faced with many redundant buildings. Prior to 2004 small amounts of Decommissioning work was in progress. Many reasons for deferring decommissioning activities were used with the predominant ones being: 1. Reduction in radiation doses to workers during the final dismantlement, 2. Development of a long-term solution for the management of radioactive wastes in Canada, 3. Financial constraints presented by the number of facilities shutdown that would require decommissioning funds and the absence of an approved funding strategy. This has led to the development of a comprehensive decommissioning plan that is all inclusive of AECL's current and legacy liabilities. Canada does not have a long-term disposal site; therefore waste minimization becomes the driving factor behind decontamination for decommissioning before and during dismantlement. This decommissioning job was a great learning experience for decommissioning and the associated contractors who worked on this project. Throughout the life of the project there was a constant focus on waste minimization. This focus was constantly in conflict with regulatory compliance primarily with respect to fire regulations and protecting the facility along with adjacent facilities during the decommissioning activities. Discrepancies in historical documents forced the project to treat every space as a contaminated space until proven differently. Decommissioning and dismantlement within an operating site adds to the complexity of the tasks especially when it is being conducted in the heart of the plant. This project was very successful with no lost time accidents in over one hundred thousand hours worked, on schedule and under budget despite some significant changes throughout the decommissioning phases. The actual cost to decommission this building will come in under 9 million dollars vs. an estimated 14.5 million dollars. This paper will cover some of the unique aspects of dismantling a radioactive building that has seen pretty much every element of the periodic table pass through it with the client requirement focused on minimization of radioactive waste volumes

  17. The movement of tritium from the Chalk River Liquid Disposal Area

    International Nuclear Information System (INIS)

    A groundwater survey has shown that tritium, as tritiated water, has migrated from the Liquid Disposal Area and spread beneath 70 acres of adjoining land. An estimated 8,250 curies beneath South Swamp and Perch Lake Swamp are advancing towards Perch Lake. A weak 'front' has already reached the lake but the concentrations are expected to rise to ten times the present value in two years. A further increase is anticipated in four years time. (author)

  18. Oxidation and dispersion of HT in the environment: The August 1986 field experiment at Chalk River

    International Nuclear Information System (INIS)

    The short-range environmental dispersion and oxidation of a release of tritiated hydrogen (HT) to the atmosphere has been studied in a field experiment. Emphasis was placed on the processes leading to the appearance of tritiated water (HTO) vapor in the atmosphere because HTO is much more radiotoxic than HT. The following conclusions were reached: No evidence was found for the rapid conversion of HT to HTO in the atmosphere; HTO observed in air, during and after the release, arose mainly from HT oxidation in the soil followed by emission of HTO; HT deposition velocities to soil ranged from 0.041 cm s-1 to 0.13 cm s-1, consistent with previous chamber measurements; the rate of HTO loss from soil, averaged over 21 d, was less than 1% h-1; and HTO concentrations in vegetation water initially increased with time after the release, then by 48 h decreased exponentially at a rate similar to soils

  19. Measuring erosion rates of contaminated cohesive sediments using laboratory and in-situ devices in combination: experiences of investigations in River Elbe and Saale

    Science.gov (United States)

    Noack, Markus; Gerbersdorf, Sabine; Hillebrand, Gudrun; Kasimir, Petra; Wieprecht, Silke

    2014-05-01

    Deposition of contaminated sediments in areas of no or low flow velocity such as groyne fields or impounded river stretches represent a significant thread to water quality if long-deposited sediments are remobilized during flood and storm events. In contrast to non-cohesive sediments the dynamics of cohesive sediments is not fully understood mainly because of multiple physico-chemical factors and variable biological influence. Hence, site-specific investigations are required to develop water management strategies as well as modelling approaches to predict the dynamic behavior of cohesive material. The Institute for Modelling Hydraulic and Environmental Systems (IWS, University of Stuttgart) has a strong experience in developing measuring strategies and techniques to deal with the complex interactions between biological and sedimentary characteristics regarding erosion and remobilization of cohesive material. Specifically, the detection of critical shear stresses for incipient motion of cohesive particles has been realized for both one laboratory device (SETEG) and an in-situ device. For site-specific investigations ideally both methods should be combined. The first method (SETEG) includes the on-site extraction of sediment cores allowing for depth-dependent analysis under controlled laboratory conditions, while the second one measures the surface only but reduces possible artifacts due to sediment withdrawal and transport. Both methods were applied at groyne fields and deposition areas of the River Elbe and River Saale, which are both heavily affected by pollution of anthropogenic contaminants mainly originating from the release of chemical industry before 1990. Next to the detection of critical shear stresses and erosion rates, further sedimentary attributes are analyzed such as particle size distribution, water content and density as well as biological attributes such as TOC and microbial mass. The analyses of the sediment cores result in vertical profiles for

  20. NMR response of non-reservoir fluids in sandstone and chalk.

    Science.gov (United States)

    van der Zwaag, C H; Stallmach, F; Skjetne, T; Veliyulin, E

    2001-01-01

    Transverse (T2) NMR relaxation time at 2 MHz proton resonance frequency was measured on core plug samples from two different lithologies, sandstone and chalk, before and after exposure to selected drilling fluids. The results show that NMR signal response was significantly altered after displacing 50% of the original pore fluids, crude oil and water, by drilling fluid filtrate. Relaxation spectra of the rock samples invaded by water-based filtrate shift to significantly shorter T2-values. This shift yields an underestimation of the free-fluid volumes when selecting cut-off values of 33 ms and 100 ms for sandstone and chalk, respectively. In opposite, rock samples affected by oil-based filtrate respond with a signal indicating significantly larger free-fluid volumes than present before exposure. NMR-permeability calculated based on the Timur-Coates Free Fluid model altered in some cases by one order of magnitude. PMID:11445352

  1. Investigation of Lecturer's Chalk by X-Ray Florescence and Fast Neutron Activation Techniques

    International Nuclear Information System (INIS)

    Different samples of lecturer's chalk were studied, using X-ray florescence (XRF) and Fast Neutron Activation Analysis (FNAA) techniques to ensure the safety of its use. The K (X-rays) and the gamma-rays were measured, using Si(Li) and high-purity germanium (HPGe) spectrometers to detect and determine qualitatively and quantitatively the constituents of the studied samples. For the investigated bulk chalk samples, the XRF was used for determination the average neutron flux of 2×107 n/cm2 sec. The concentrations of the elements (Ca and small traces of Al, Fe, Mg and Si) were measured and their presence was confirmed by γ-ray, lifetime and/or XRF measurements.

  2. Seismic architecture of the Chalk Group from onshore reflection data in eastern Denmark

    DEFF Research Database (Denmark)

    Moreau, Julien; Anderskouv, Kresten; Boldreel, Lars Ole;

    The Upper Cretaceous-Danian chalk is well exposed in the 14 km long coastal cliff of Stevns Klint (eastern Denmark). The cliff is a world renowned for its spectacular exposure of the Cretaceous-Palaeogene boundary. Based on regional geological knowledge of the field and cores, the characteristics...... completed with the acquisition of an extensive set of subsurface data. The data include high resolution 2D multichannel seismics onshore and offshore, a seismic refraction profile, two entirely cored boreholes including wireline logs, GPR cross-hole tomography, thermographic analysis, etc. We intend...... to compile and merge the geological and geophysical datasets to investigate the variation of the Chalk Group properties and their signature in the subsurface. In this communication, the seismic reflection data are being analysed. Very high resolution litho-, bio- and cyclostratigraphy can be correlated...

  3. Gas compositions and processes in the unsaturated zone of the chalk and triassic sandstone aquifers, England

    International Nuclear Information System (INIS)

    Comparatively little is known about the nature of gas sources, sinks and transport in the unsaturated zone, yet this topic is of importance to a wide range of activities extending from agriculture to the construction industry. The composition of the unsaturated zone atmosphere in two different English aquifer types (Chalk and Triassic sandstone) was investigated by the construction of gas sampling boreholes with depths of up to 25 m. Monitoring took place at approximately 1-2 month intervals over 12-24 months. No significant seasonal variations in gas composition were noted. The following mean concentrations of gases was observed (Chalk, sandstone): N2 (77.7%, 77.7%), O2 (19.5%, 19.8%), CO2 (1.5%, 1.5%), N2O (4.2 ppmv, 2.4 ppmv), CH4 (0.1 ppmv, 0.3 ppmv), and δ13C-CO2 (-25.3 per mille, -19.9 per mille). The factor of 50 increase in CO2 reflects production from soil organic matter, supplemented in the sandstone by some CO2 from acidification or carbonate material. The decrease in O2 of little more than 1% absolute from atmospheric concentration indicates the persistence of oxidizing conditions in both unsaturated zones, and the relatively high concentrations of N2O therefore appear likely to have been derived from nitrification rather than denitrification. The limited magnitude of denitrification processes is further illustrated by N2/Ar and δ15N data. To understand better the rate of movement of gases in the unsaturated zone of a fissured aquifer, a tracer test using SF6 was carried out at the Chalk site. The results indicate a diffusion rate up to 103 times higher than that expected for the Chalk matrix alone. (author)

  4. Probing the intrinsically oil-wet surfaces of pores in North Sea chalk at subpore resolution

    OpenAIRE

    Hassenkam, T.; Skovbjerg, L. L.; Stipp, S. L. S.

    2009-01-01

    Pore surface properties control oil recovery. This is especially true for chalk reservoirs, where pores are particularly small. Wettability, the tendency for a surface to cover itself with fluid, is traditionally defined by the angle a droplet makes with a surface, but this macroscopic definition is meaningless when the particles are smaller than even the smallest droplet. Understanding surface wetting, at the pore scale, will provide clues for more effective oil recovery. We used a special m...

  5. Rock physics interpolation Used for velocity modeling of chalks: Ontong Java plateau example

    OpenAIRE

    Saberi, Mohammad Reza; Johansen, Tor Arne; Sælen, Gunnar

    2010-01-01

    Chalks are pelagic carbonate sediments that are deposited in deep-water environments. Their elastic behaviour is controlled by a combination of depositional conditions and subsequent diagenesis. In this paper, we incorporate geological information into rock physics modeling by constraining the pore structure (aspect ratio) variability. The strategy is to define a pore-model that reflects lithology, porosity and velocity. Then, a background velocity cube is constructed based on inf...

  6. Investigated Miscible CO2 Flooding for Enhancing Oil Recovery in Wettability Altered Chalk and Sandstone Rocks

    Energy Technology Data Exchange (ETDEWEB)

    Tabrizy, Vahid Alipour

    2012-07-01

    The thesis addresses oil recovery by miscible CO2 flooding from modified sandstone and chalk rocks. Calcite mineral surface is modified with stearic acid (SA) and asphaltene, and the silicate mineral surfaces are modified with N,N-dimethyldodecylamine (NN-DMDA) and asphaltene. The stability of adsorbed polar components in presence of SO4 2- and Mg2 + ions is also investigated. Recovery from sandstone cores is consistently lower than that from chalk cores saturated with the same oil and flooded with CO2 at all miscible flooding conditions. This may be due to the larger permeability contrasts in sandstone cores, which promote the fingering phenomenon. Miscible CO2 flooding for chalk and sandstone cores with distilled water, as initial water saturation, shows also lower oil recovery than cores saturated with different ions. At higher miscible flooding conditions, higher oil recovery is obtained. However, presence of light components (such as C1 or C3) in oil reduced the recovery. Oil recovery in presence of methane (C1) is lower than that in presence of methane and propane (C1/C3). A ternary diagram was constructed in order to understand the CO2 flooding mechanism(s) at the different flooding conditions and in presence of light components. The side effect of the flooding with CO2 is the probability for asphaltene deposition. An approach based on solubility parameter in the liquid, is used to assess the risk for asphaltene deposition during CO2 miscible flooding. The light components (C1/C3) and higher flooding conditions enhanced the risk for asphaltene instability. It is also shown higher amount of asphaltene deposition in chalk cores than that in sandstone cores at similar miscibility conditions.(au)

  7. Palaeo-ages of groundwaters in a fissured chalk aquifer, United Kingdom

    International Nuclear Information System (INIS)

    The Chalk aquifer in southeast England has a classic dual-porosity structure, with bulk advection occurring primarily in fractures/fissures, and largely immobile storage in the highly porous matrix blocks. For pumped samples, estimates of groundwater residence times using traditional geochemical correction models with 14C-dating, and assuming that ages reflect mobile fissure water signatures, indicate late-glacial recharge (≥25ka BP, pre-dating the Last Glacial Maximum (LGM) in the UK c.18 ka BP) for groundwaters in the centre of the basin. Cooler recharge temperatures than for modem waters evidenced in environmental isotopic (δ2H, δ18O) and dissolved noble gas (Ne, Ar, Kr, Xe) contents confirm their palaeowater status. However, hydraulic age estimates for transit times from recharge are much younger (tens of years). Closer consideration of solute transport in the Chalk allows reconciliation of these apparently discordant ages. It is argued that, on the regional aquifer scale, environmental tracers in the fissured Chalk move as though in an Equivalent Porous Medium (EPM), with significant tracer retardation due to sorption and/or matrix diffusion effects. Downgradient trends in δ18O and noble gases as independent tracers of past climatic changes can then be used to further constrain the groundwater ages better than for 14C-dating alone. This approach points to a significant revision of groundwater ages in the aquifer; all ages are seen to reflect post-glacial recharge having occurred ≤13 ka BP. An important consequence of this revision is that it is suggested that traditional geochemical models potentially undercorrect for the full effect of hydrodynamic processes on tracer ages in fissured porous media like the Chalk. (author)

  8. Biot critical frequency applied as common friction factor for pore collapse and failure of chalk with different pore fluids and temperatures

    DEFF Research Database (Denmark)

    Andreassen, Katrine Alling; Fabricius, Ida Lykke; Foged, Niels Nielsen

    2011-01-01

    A fluid effect toward higher strengths for oil-saturated chalk compared with water-saturated chalk has previously been identified and labeled the "water-weakening phenomenon," but has not been further characterized physically. The hypothesis of this paper is that the Biot critical frequency with ...... present a new test series on Stevns chalk with unconfined compression and Brazilian strength results. Copyright © 2011 Society of Petroleum Engineers....

  9. Late Cretaceous (late Campanian-Maastrichtian) sea-surface temperature record of the Boreal Chalk Sea

    Science.gov (United States)

    Thibault, Nicolas; Harlou, Rikke; Schovsbo, Niels H.; Stemmerik, Lars; Surlyk, Finn

    2016-02-01

    The last 8 Myr of the Cretaceous greenhouse interval were characterized by a progressive global cooling with superimposed cool/warm fluctuations. The mechanisms responsible for these climatic fluctuations remain a source of debate that can only be resolved through multi-disciplinary studies and better time constraints. For the first time, we present a record of very high-resolution (ca. 4.5 kyr) sea-surface temperature (SST) changes from the Boreal epicontinental Chalk Sea (Stevns-1 core, Denmark), tied to an astronomical timescale of the late Campanian-Maastrichtian (74 to 66 Ma). Well-preserved bulk stable isotope trends and calcareous nannofossil palaeoecological patterns from the fully cored Stevns-1 borehole show marked changes in SSTs. These variations correlate with deep-water records of climate change from the tropical South Atlantic and Pacific oceans but differ greatly from the climate variations of the North Atlantic. We demonstrate that the onset and end of the early Maastrichtian cooling and of the large negative Campanian-Maastrichtian boundary carbon isotope excursion are coincident in the Chalk Sea. The direct link between SSTs and δ13C variations in the Chalk Sea reassesses long-term glacio-eustasy as the potential driver of carbon isotope and climatic variations in the Maastrichtian.

  10. Late Cretaceous (Late Campanian–Maastrichtian sea surface temperature record of the Boreal Chalk Sea

    Directory of Open Access Journals (Sweden)

    N. Thibault

    2015-11-01

    Full Text Available The last 8 Myr of the Cretaceous greenhouse interval were characterized by a progressive global cooling with superimposed cool/warm fluctuations. The mechanisms responsible for these climatic fluctuations remain a source of debate that can only be resolved through multi-disciplinary studies and better time constraints. For the first time, we present a record of very high-resolution (ca. 4.5 kyr sea-surface temperature (SST changes from the Boreal epicontinental Chalk Sea (Stevns-1 core, Denmark, tied to an astronomical time scale of the late Campanian–Maastrichtian (74 to 66 Myr. Well-preserved bulk stable isotope trends and calcareous nannofossil palaeoecological patterns from the fully cored Stevns-1 borehole show marked changes in SSTs. These variations correlate with deep-water records of climate change from the tropical South Atlantic and Pacific oceans but differ greatly from the climate variations of the North Atlantic. We demonstrate that the onset and end of the early Maastrichtian cooling and of the large negative Campanian–Maastrichtian boundary carbon isotope excursion are coincident in the Chalk Sea. The direct link between SSTs and δ13C variations in the Chalk Sea reassesses long-term glacio-eustasy as the potential driver of carbon isotope and climatic variations in the Maastrichtian.

  11. Late Cretaceous (Late Campanian-Maastrichtian) sea surface temperature record of the Boreal Chalk Sea

    Science.gov (United States)

    Thibault, N.; Harlou, R.; Schovsbo, N. H.; Stemmerik, L.; Surlyk, F.

    2015-11-01

    The last 8 Myr of the Cretaceous greenhouse interval were characterized by a progressive global cooling with superimposed cool/warm fluctuations. The mechanisms responsible for these climatic fluctuations remain a source of debate that can only be resolved through multi-disciplinary studies and better time constraints. For the first time, we present a record of very high-resolution (ca. 4.5 kyr) sea-surface temperature (SST) changes from the Boreal epicontinental Chalk Sea (Stevns-1 core, Denmark), tied to an astronomical time scale of the late Campanian-Maastrichtian (74 to 66 Myr). Well-preserved bulk stable isotope trends and calcareous nannofossil palaeoecological patterns from the fully cored Stevns-1 borehole show marked changes in SSTs. These variations correlate with deep-water records of climate change from the tropical South Atlantic and Pacific oceans but differ greatly from the climate variations of the North Atlantic. We demonstrate that the onset and end of the early Maastrichtian cooling and of the large negative Campanian-Maastrichtian boundary carbon isotope excursion are coincident in the Chalk Sea. The direct link between SSTs and δ13C variations in the Chalk Sea reassesses long-term glacio-eustasy as the potential driver of carbon isotope and climatic variations in the Maastrichtian.

  12. Effect of activities at the Idaho National Engineering and Environmental Laboratory on the water quality of the Snake River Plain aquifer in the Magic Valley study

    Science.gov (United States)

    Bartholomay, Roy C.

    1998-01-01

    Radiochemical and chemical constituents in wastewater generated at facilities of the Idaho National Engineering and Environmental Laboratory (INEEL) (figure 1) have been discharged to waste-disposal ponds and wells since the early 1950 s. Public concern has been expressed that some of these constituents could migrate through the Snake River Plain aquifer to the Snake River in the Twin Falls-Hagerman area Because of these concerns the U.S. Department of Energy (DOE) requested that the U.S. Geological Survey (USGS) conduct three studies to gain a greater understanding of the chemical quality of water in the aquifer. One study described a one-time sampling effort for radionuclides, trace elements, and organic compounds in the eastern part of the A&B Irrigation District in Minidoka County (Mann and Knobel, 1990). Another ongoing study involves sampling for tritium from 19 springs on the north side of the Snake River in the Twin Falls-Hagerman area (Mann, 1989; Mann and Low, 1994). A third study an ongoing annual sampling effort in the area between the southern boundary of the INEEL and Hagerman (figure 1) (hereafter referred to as the Magic Valley study area), is being conducted with the Idaho Department of Water Resources in cooperation with the DOE. Data for a variety of radiochemical and chemical constituents from this study have been published by Wegner and Campbell (1991); Bartholomay, Edwards, and Campbell (1992, 1993, 1994a, 1994b); and Bartholomay, Williams, and Campbell (1995, 1996, 1997b). Data discussed in this fact sheet were taken from these reports. An evaluation of data collected during the first four years of this study (Bartholomay Williams, and Campbell, 1997a) showed no pattern of water-quality change for radionuclide data as concentrations randomly increased or decreased. The inorganic constituent data showed no statistical change between sample rounds.

  13. Comparison of FLOWTRAN predictions of onset of significant voiding (OSV) to Savannah River Heat Transfer Laboratory subcooled boiling flow instability measurements, Part 1

    International Nuclear Information System (INIS)

    The onset of flow instability (OFI) was measured in the first of a scheduled series of subcooled boiling tests at the Savannah River Heat Transfer Laboratory (HTL). This report summarizes the benchmarking of predictions of the onset of significant voiding (OSV) using Version 16 of the FLOWTRANΩ reactor limits code against the HTL measurements. This study confirms that, for this series of HTL subcooled boiling tests, the Saha-Zuber OSV correlation was a conservative indicator of OFI for Peclet numbers between 30,000 and 80,000. The Saha-Zuber correlation was not a conservative indicator of OFI for Peclet numbers below 30,000. A conservative bound to the Saha-Zuber correlation (the Saha-Zuber constant Stanton number criterion -- 30%) was agreed to at a meeting of SRL, DOE, and the DOE EH and DP review panels. This bound was a conservative indicator of OFI for all measurements in this study

  14. Estimation of hydraulic properties and development of a layered conceptual model for the Snake River plain aquifer at the Idaho National Engineering Laboratory, Idaho

    Energy Technology Data Exchange (ETDEWEB)

    Frederick, D.B.; Johnson, G.S.

    1996-02-01

    The Idaho INEL Oversight Program, in association with the University of Idaho, Idaho Geological Survey, Boise State University, and Idaho State University, developed a research program to determine the hydraulic properties of the Snake River Plain aquifer and characterize the vertical distribution of contaminants. A straddle-packer was deployed in four observation wells near the Idaho Chemical Processing Plant at the Idaho National Engineering Laboratory. Pressure transducers mounted in the straddle-packer assembly were used to monitor the response of the Snake River Plain aquifer to pumping at the ICPP production wells, located 2600 to 4200 feet from the observation wells. The time-drawdown data from these tests were used to evaluate various conceptual models of the aquifer. Aquifer properties were estimated by matching time-drawdown data to type curves for partially penetrating wells in an unconfined aquifer. This approach assumes a homogeneous and isotropic aquifer. The hydraulic properties of the aquifer obtained from the type curve analyses were: (1) Storativity = 3 x 10{sup -5}, (2) Specific Yield = 0.01, (3) Transmissivity = 740 ft{sup 2}/min, (4) Anisotropy (Kv:Kh)= 1:360.

  15. Development of a regional groundwater flow model for the area of the Idaho National Engineering Laboratory, Eastern Snake River Plain Aquifer

    International Nuclear Information System (INIS)

    This report documents a study conducted to develop a regional groundwater flow model for the Eastern Snake River Plain Aquifer in the area of the Idaho National Engineering Laboratory. The model was developed to support Waste Area Group 10, Operable Unit 10-04 groundwater flow and transport studies. The products of this study are this report and a set of computational tools designed to numerically model the regional groundwater flow in the Eastern Snake River Plain aquifer. The objective of developing the current model was to create a tool for defining the regional groundwater flow at the INEL. The model was developed to (a) support future transport modeling for WAG 10-04 by providing the regional groundwater flow information needed for the WAG 10-04 risk assessment, (b) define the regional groundwater flow setting for modeling groundwater contaminant transport at the scale of the individual WAGs, (c) provide a tool for improving the understanding of the groundwater flow system below the INEL, and (d) consolidate the existing regional groundwater modeling information into one usable model. The current model is appropriate for defining the regional flow setting for flow submodels as well as hypothesis testing to better understand the regional groundwater flow in the area of the INEL. The scale of the submodels must be chosen based on accuracy required for the study

  16. Estimation of hydraulic properties and development of a layered conceptual model for the Snake River plain aquifer at the Idaho National Engineering Laboratory, Idaho

    International Nuclear Information System (INIS)

    The Idaho INEL Oversight Program, in association with the University of Idaho, Idaho Geological Survey, Boise State University, and Idaho State University, developed a research program to determine the hydraulic properties of the Snake River Plain aquifer and characterize the vertical distribution of contaminants. A straddle-packer was deployed in four observation wells near the Idaho Chemical Processing Plant at the Idaho National Engineering Laboratory. Pressure transducers mounted in the straddle-packer assembly were used to monitor the response of the Snake River Plain aquifer to pumping at the ICPP production wells, located 2600 to 4200 feet from the observation wells. The time-drawdown data from these tests were used to evaluate various conceptual models of the aquifer. Aquifer properties were estimated by matching time-drawdown data to type curves for partially penetrating wells in an unconfined aquifer. This approach assumes a homogeneous and isotropic aquifer. The hydraulic properties of the aquifer obtained from the type curve analyses were: (1) Storativity = 3 x 10-5, (2) Specific Yield = 0.01, (3) Transmissivity = 740 ft2/min, (4) Anisotropy (Kv:Kh)= 1:360

  17. Aquatic Research Laboratory (ARL)

    Data.gov (United States)

    Federal Laboratory Consortium — Columbia River and groundwater well water sources are delivered to the Aquatic Research Laboratory (ARL), where these resources are used to conduct research on fish...

  18. RadBall™ Technology Testing in the Savannah River Site’s Health Physics Instrument Calibration Laboratory

    OpenAIRE

    Farfán, Eduardo B.; Foley, Trevor Q.; Jannik, G. Timothy; Harpring, Larry J.; Gordon, John R.; Blessing, Ronald; Coleman, J. Rusty; Holmes, Christopher J.; Oldham, Mark; Adamovics, John; Stanley, Steven J.

    2010-01-01

    The United Kingdom’s National Nuclear Laboratory (NNL) has developed a radiation-mapping device that can locate and quantify radioactive hazards within contaminated areas of the nuclear industry. The device, known as RadBall™, consists of a colander-like outer collimator that houses a radiation-sensitive polymer sphere. The collimator has over two hundred small holes; thus, specific areas of the polymer sphere are exposed to radiation becoming increasingly more opaque in proportion to the abs...

  19. Multi-model comparison of a major flood in the groundwater-fed basin of the Somme River (France)

    OpenAIRE

    F. Habets; Gascoin, S.; S. Korkmaz; Thiéry, D; Zribi, M.; Amraoui, N.; Carli, M; A. Ducharne; Leblois, E.; E. Ledoux; Martin, E.; Noilhan, J.; C. Ottlé; P. Viennot

    2009-01-01

    The Somme River Basin is located above a chalk aquifer and the discharge of the somme River is highly influenced by groundwater inflow (90% of river discharge is baseflow). In 2001, the Somme River Basin suffered from a major flood causing damages estimated to 100 million Euro (Deneux and Martin, 2001). The purpose of the present research is to evaluate the ability of four hydrologic models to reproduce flood events in the Somme River Basin over an 18-year period, by comparison with observed ...

  20. The 1988 INEL [Idaho National Engineering Laboratory] microearthquake survey near the western edge of the eastern Snake River Plain

    International Nuclear Information System (INIS)

    A network of seventeen analog recording seismograph, spaced approximately 2 km apart, were operated from May to November, 1988 near the western edge of the eastern Snake River Plain (ESRP) to record small magnitude microearthquakes. Two three-component digital seismographs were also installed to record the microearthquake activity for analysis of earthquake source parameters and any regional earthquakes for possible analysis of the localized site and crustal effects of the ESRP on earthquake ground motions. We determined near-surface crustal velocities for this area that were slightly lower than the near-surface crustal velocities presently used in routine locations of events recorded by the INEL Seismic Network from five 100 lb surface blasts. During the survey period, only two earthquakes were located near the network area. One of the events occurred in May and was recorded by four of the portable seismic stations and two of the permanent INEL Seismic Network stations. It had a coda magnitude (Mc) of approximately 0.3. The other event was recorded by seventeen portable analog stations and three of the permanent INEL Seismic Network stations. We located this microearthquake, Mc=0.5, about 2 km west of Howe, Idaho, off of the ESRP. We determined an unconstrained focal mechanism for this event, which could be interpreted as normal faulting striking N 44 degree W or strike-slip faulting on a plane striking either N 44 degree W or N 47 degree E. 26 refs., 10 figs., 3 tabs

  1. Shipment of 255 DIDO fuel elements to the Savannah River Site to empty the storage and reactor pools at Risoe National Laboratory

    International Nuclear Information System (INIS)

    The DR-3 reactor, owned and operated by the Danish National Laboratory, was built in the late 1950's and initiated operation in January 1960. At that time the DR-1 and DR-2 reactors were already in operation. The main purpose if of Danish research reactor DR-3 was material and fuel testing. Until 1989 the reactor utilized HEU fuel elements. Conversion to the LEU fuel cycle was accomplished in 1990. DOE restarted the return program of for Foreign Research Reactor fuel elements to the United States in 1994. From that time, through 1998, three IUO4 casks (one cask in 1994) operated by Transnucleaire (now named Cogema Logistics, ACL) were used to transport Risoe's fuel to the Savannah River Site (SRS) near Aiken, SC in the USA. In 1999, Risoe elected to issue a request for proposal to transport DR-3 the DIDO fuel elements to SRS with a new licensed cask designed to replace the IUO4 cask. ACL was awarded the contract to transport the irradiated fuel from DR-3 to SRS for the remainder of the FRR Fuel Return program (2009). However, on September 28, 2000, the Board of Governors of Risoe National Laboratory decided to shut down the Danish research reactor of DR3. There had been of R2 technical problems (corrosion on the aluminum reactor tank) and, due to anticipated increasing operational expenses, the Board elected to close the reactor facility. Shortly thereafter, the Danish Government asked the National Laboratory to empty the reactor and its reactor and storage pools containing a total of 255 Dido irradiated fuel elements and ship them to Savannah Rive Site. At that time, ACL was in the process of licensing the new TN-MTR package in the USA. The early shut down of the DR-3 reactor and consequently the resultant new shipping schedule was not compatible with ACL's equipment and licensing schedule for the cask. (author)

  2. The effect of divalent ions on the elasticity and pore collapse of chalk evaluated from compressional wave velocity and low-field Nuclear Magnetic Resonance (NMR)

    DEFF Research Database (Denmark)

    Katika, Konstantina; Addassi, Mouadh; Alam, Mohammad Monzurul;

    2015-01-01

    The effects of divalent ions on the elasticity and the pore collapse of chalk were studied through rock-mechanical testing and low-field Nuclear Magnetic Resonance (NMR) measurements. Chalk samples saturated with deionized water and brines containing sodium, magnesium, calcium and sulfate ions were...

  3. High resolution microgravity investigations for the detection and characterisation of subsidence associated with abandoned, coal, chalk and salt mines

    Energy Technology Data Exchange (ETDEWEB)

    Styles, P.; Toon, S.; Branston, M.; England, R. [Keele Univ., Applied And Environmental Geophysics Group, School of Physical and Geographical Sciences (United Kingdom); Thomas, E.; Mcgrath, R. [Geotechnology, Neath (United Kingdom)

    2005-07-01

    The closure and decay of industrial activity involving mining has scarred the landscape of urban areas and geo-hazards posed by subsurface cavities are ubiquitous throughout Europe. Features of concern consist of natural solution cavities (e.g. swallow holes and sinkholes in limestone gypsum and chalk) and man-made cavities (mine workings, shafts) in a great variety of post mining environments, including coal, salt, gypsum, anhydrite, tin and chalk. These problems restrict land utilisation, hinder regeneration, pose a threat to life, seriously damage property and services and blight property values. This paper outlines the application of microgravity techniques to characterise abandoned mining hazard in case studies from Coal, Chalk and Salt Mining environments in the UK. (authors)

  4. High resolution microgravity investigations for the detection and characterisation of subsidence associated with abandoned, coal, chalk and salt mines

    International Nuclear Information System (INIS)

    The closure and decay of industrial activity involving mining has scarred the landscape of urban areas and geo-hazards posed by subsurface cavities are ubiquitous throughout Europe. Features of concern consist of natural solution cavities (e.g. swallow holes and sinkholes in limestone gypsum and chalk) and man-made cavities (mine workings, shafts) in a great variety of post mining environments, including coal, salt, gypsum, anhydrite, tin and chalk. These problems restrict land utilisation, hinder regeneration, pose a threat to life, seriously damage property and services and blight property values. This paper outlines the application of microgravity techniques to characterise abandoned mining hazard in case studies from Coal, Chalk and Salt Mining environments in the UK. (authors)

  5. Marine macrofossil communities in the uppermost Maastrichtian chalk of Stevns Klint, Denmark

    DEFF Research Database (Denmark)

    Hansen, Thomas; Surlyk, Finn

    2014-01-01

    -erosive bottom currents. It is draped by the upper Sigerslev Member, which was laid down in deeper water than any other chalk known from onshore Denmark. Deposition took place under quiet conditions, apparently not influenced by bottom currents. The sparse level-bottom community lived on a seafloor with low...... similarly mound-bedded lower Sigerslev Member. The number of polychaete species is also greater in the Højerup Member. The faunal differences reflect the shallower-water setting and a higher influx of food during deposition of the latter unit. The final Maastrichtian benthic macrofossil community at Stevns...

  6. Optimization of Spore Forming Bacteria Flooding for Enhanced Oil Recovery in North Sea Chalk Reservoir

    OpenAIRE

    Halim, Amalia Yunita; Nielsen, Sidsel Marie; Eliasson Lantz, Anna; Shapiro, Alexander

    2015-01-01

    Little has been done to study microbial enhanced oil recovery (MEOR) in chalk reservoirs. The present study focused on core flooding experiments to see microbial plugging and its effect on oil recovery. A pressure tapped core holder with pressure ports at 1.2 cm, 3.8 cm, and 6.3 cm from the inlet was used for this purpose. A spore forming bacterium, Bacillus licheniformis 421, was used as it was shown to be a good candidate in the previous study. Bacterial spore can penetrate deeper into the ...

  7. Prospects of Microbial Enhanced Oil Recovery  in Danish chalk rocks

    DEFF Research Database (Denmark)

    Rudyk, Svetlana Nikolayevna; Jørgensen, Leif Wagner; Bah Awasi, Ismail

      Microbial Enhanced Oil Recovery (MEOR) uses bacteria, producing gas (CO2), polymers or surfactants to help recover residual oil after the water injection depletes its possibilities. Two strains of Clostridia tyrobutiricum were investigated as possible candidates for MEOR  implementation in Danish...... chalk reservoir rocks. Parameters such as high salinity, low permeability, high temperature and toxic elements, being typical characteristics of Danish fields can cause limiting effects on MEOR applications. The work fulfilled showed that microbes can be adapted to higher salinities through a serial...

  8. CO2-foaming agent retention in fractured chalk models: Experiments and simulations

    OpenAIRE

    Kvæstad, Ann Helen

    2011-01-01

    Injection of CO2-gas can improve the oil recovery. In naturally fractured reservoirs such as chalk, injection of CO2-gas can result in early gas breakthrough because the gas can use the fractures as pathways from the injector to the producer. The pressure, temperature and oil properties in the reservoir can also lead to an unfavorable mobility for the gas. This can lead to low total sweep efficiency for the process. One method to increase the total sweep efficiency in the fractured reservoir ...

  9. Optimization of Spore Forming Bacteria Flooding for Enhanced Oil Recovery in North Sea Chalk Reservoir

    DEFF Research Database (Denmark)

    Halim, Amalia Yunita; Nielsen, Sidsel Marie; Eliasson Lantz, Anna;

    2015-01-01

    was used for this purpose. A spore forming bacterium, Bacillus licheniformis 421, was used as it was shown to be a good candidate in the previous study. Bacterial spore can penetrate deeper into the chalk rock, squeezing through the pore throats. Our results show that B. licheniformis 421 when......-1.2 cm and 1.2-3.8 cm) during bacteria injection. Further seawater flooding after three days shut in period showed that permeability gradually increased in the first two sections of the core and started to decrease in the third section of the core (3.8-6.3 cm). Complete plugging was never observed in our...

  10. Burial diagenesis of deep sea chalk as reflected in Biot’s coefficient

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke; Alam, Mohammad Monzurul

    particles apparently is low and not correlated with porosity, probably because the pore-filling cementation in this interval causes Biot’s coefficient to decline as burial increases. Limestone from the water zone of the North sea Chalk Group follows the same stress trend as deep sea limestone. These results...... limestone as burial increases and porosity decreases. The porosity decrease is accompanied by an increasing velocity to elastic waves, and consequently a decreasing Biot’s coefficient, as estimated from velocity and density of core samples. When the effective burial stress is normalized to total horizontal...

  11. Burial diagenesis of deep sea chalk as reflected in Biot's coefficient

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke; Alam, Mohammad Monzurul

    particles apparently is low and not correlated with porosity, probably because the pore-filling cementation in this interval causes Biot's coefficient to decline as burial increases. Limestone from the water zone of the North sea Chalk Group follows the same stress trend as deep sea limestone. These results...... limestone as burial increases and porosity decreases. The porosity decrease is accompanied by an increasing velocity to elastic waves, and consequently a decreasing Biot's coefficient, as estimated from velocity and density of core samples. When the effective burial stress is normalized to total horizontal...

  12. Tracking selenium in the Chalk aquifer of northern France: Sr isotope constraints

    International Nuclear Information System (INIS)

    Highlights: • We report the chemistry of the Chalk groundwater affected by Se contamination. • Strontium isotopes were used to identify the groundwater bodies and their mixings. • The spatial and temporal Se variability is mainly linked to the presence of Se-rich clays. • Saturation or desaturation of Se-rich clays control Se mobility. - Abstract: Groundwater at the southern and eastern edges of France’s Paris Basin has a selenium content that at times exceeds the European Framework Directive’s drinking-water limit value of 10 μg/L. To better understand the dynamics of the Chalk groundwater being tapped to supply the city of Lille and the Se origins, we used a combination of geochemical and isotopic tools. Strontium isotopes, coupled with Ca/Sr, Mg/Sr and Se/Sr ratios, were used to identify the main groundwater bodies and their mixings, with the Mg/Sr and Se/Sr ratios constraining a ternary system. Groundwater in the agricultural aquifer-recharge zone represents a first end-member and displays the youngest water ages of the catchment along with the highest Sr isotopic signature (0.70842) and low Se contents. Anaerobic groundwater constitutes a second major end-member affected by water-rock interactions over a long residence time, with the lowest Sr isotopic signature (0.70789) and the lowest Se content, its low SF6 content confirming the contribution of old water. Se-rich groundwater containing up to 30 μg/L of Se represents a third major end-member, with an intermediate Sr isotopic ratio (0.70826), and is mainly constrained by the clayey Se-rich formation overlying the Chalk aquifer. The spatial and temporal Se variability in the groundwater is clearly linked to the presence of this formation identified as Tertiary and also to the hydrological conditions; saturation of the Se-rich clays by oxygenated groundwater enhances Se mobility and also Sr adsorption onto the clays. This multi-tool study including Sr isotopes successfully identified the Se

  13. Full-waveform Inversion of Crosshole GPR Data Collected in Strongly Heterogeneous Chalk: Challenges and Pitfalls

    DEFF Research Database (Denmark)

    Keskinen, Johanna; Zibar, Majken Caroline Looms; Nielsen, Lars; Klotzsche, Anja; van der Kruk, Jan; Moreau, Julien; Stemmerik, Lars; Holliger, Klaus

    Chalk is an important reservoir rock for hydrocarbons and for groundwater resources for many major cities. Therefore, this rock type has been extensively investigated using both geological and geophysical methods. Many applications of crosshole GPR tomography rely on the ray approximation and...... address the importance of (i) adequate starting models, both in terms of the dielectric permittivity and the electrical conductivity, (ii) the estimation of the source wavelet, (iii) and the effects of data sampling density when imaging this rock type. Moreover, we discuss the resolution of the bedding...

  14. Waveform analysis of crosshole GPR data collected in heterogeneous chalk deposits

    DEFF Research Database (Denmark)

    Keskinen, Johanna; Nielsen, Lars; Zibar, Majken Caroline Looms;

    2014-01-01

    be divided into two main units based on the traveltime analysis and interpretation of the cored material from the boreholes. The lower unit consists mainly of porous calcareous mudstone with occasional occurrences of flint nodules. The upper succession is c. 8 m thick and is fairly heterogeneous...... methods are highly dependent on the quality of the starting models (usually obtained from ray-based tomography), as well as on the assumptions made regarding the source signal. Adequate estimation of starting models and source waveform is, however, a challenging task for the strongly heterogeneous chalk...

  15. Bioremediation of Petroleum and Radiological Contaminated Soils at the Savannah River Site: Laboratory to Field Scale Applications

    Energy Technology Data Exchange (ETDEWEB)

    BRIGMON, ROBINL.

    2004-06-07

    In the process of Savannah River Site (SRS) operations limited amounts of waste are generated containing petroleum, and radiological contaminated soils. Currently, this combination of radiological and petroleum contaminated waste does not have an immediate disposal route and is being stored in low activity vaults. SRS developed and implemented a successful plan for clean up of the petroleum portion of the soils in situ using simple, inexpensive, bioreactor technology. Treatment in a bioreactor removes the petroleum contamination from the soil without spreading radiological contamination to the environment. This bioreactor uses the bioventing process and bioaugmentation or the addition of the select hydrocarbon degrading bacteria. Oxygen is usually the initial rate-limiting factor in the biodegradation of petroleum hydrocarbons. Using the bioventing process allowed control of the supply of nutrients and moisture based on petroleum contamination concentrations and soil type. The results of this work have proven to be a safe and cost-effective means of cleaning up low level radiological and petroleum-contaminated soil. Many of the other elements of the bioreactor design were developed or enhanced during the demonstration of a ''biopile'' to treat the soils beneath a Polish oil refinery's waste disposal lagoons. Aerobic microorganisms were isolated from the aged refinery's acidic sludge contaminated with polycyclic aromatic hydrocarbons (PAHs). Twelve hydrocarbon-degrading bacteria were isolated from the sludge. The predominant PAH degraders were tentatively identified as Achromobacter, Pseudomonas Burkholderia, and Sphingomonas spp. Several Ralstonia spp were also isolated that produce biosurfactants. Biosurfactants can enhance bioremediation by increasing the bioavailability of hydrophobic contaminants including hydrocarbons. The results indicated that the diversity of acid-tolerant PAH-degrading microorganisms in acidic oil wastes may

  16. Environmental isotope studies related to groundwater flow and saline encroachment in the chalk aquifer of Lincolnshire, England

    International Nuclear Information System (INIS)

    The isotopes of tritium and carbon are used to study part of the North Lincolnshire Chalk aquifer in England. The tritium data support the view that the aquifer is a thin fissure system and indicate that some changes in flow direction have occurred owing to recent abstraction. The data are also consistent with other chemical data in elucidating groundwater entering the Chalk from deeper aquifers. Carbon isotopes are used to distinguish between saline water bodies and suggest that saline water was entrapped within the aquifer in the Eemian and Flandrian stages of the Pleistocene. (author)

  17. The relation among porosity, permeability, and specific surface of chalk from the Gorm field, Danish North Sea

    DEFF Research Database (Denmark)

    Jeanette, Mortensen; Engstrøm, Finn; Lind, Ida

    1998-01-01

    The origin to the difference in the relationship between permeability and porosity for Danian and Maastrichtian chalk from the Gorm field offshore Denmark has been investigated. The investigation was based on 300 sets of core data (He-expansion porosity and air permeability) from the well Gorm N-22...... surface. Furthermore it was found that the nature of porosity (intrafossil, intergranular, etc.) had no significant influence on the air permeability, so that the permeability of the chalk can be calculated from total porosity and specific surface. Kozeny's empirical constant, c, was here determined...... analytically from a simple porosity model and Poiseuilles law....

  18. The Deep River Science Academy: a unique and innovative program for engaging students in science

    Energy Technology Data Exchange (ETDEWEB)

    Turner, C.W., E-mail: carlrhonda.turner@sympatico.ca [Deep River Science Academy, Deep River, Ontario (Canada); Didsbury, R. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Ingram, M. [Deep River Science Academy, Deep River, Ontario (Canada)

    2014-06-15

    For 28 years, the Deep River Science Academy (DRSA) has been offering high school students the opportunity to engage in the excitement and challenge of professional scientific research to help nurture their passion for science and to provide them with the experience and the knowledge to make informed decisions regarding possible future careers in the fields of science, technology, engineering, and mathematics (STEM). The venue for the DRSA program has been a six-week summer science camp where students, working in pairs under the guidance of a university undergraduate tutor, contribute directly to an on-going research program under the supervision of a professional scientist or engineer. This concept has been expanded in recent years to reach students in classrooms year round by engaging students via the internet over a 12-week term in a series of interactive teaching sessions based on an on-going research project. Although the research projects for the summer program are offered primarily from the laboratories of Atomic Energy of Canada Limited at its Chalk River Laboratories site, projects for the year-round program can be based, in principle, in laboratories at universities and other research institutes located anywhere in Canada. This paper will describe the program in more detail using examples illustrating how the students become engaged in the research and the sorts of contributions they have been able to make over the years. The impact of the program on the students and the degree to which the DRSA has been able to meet its objective of encouraging students to choose careers in the fields of STEM and equipping them with the skills and experience to be successful will be assessed based on feedback from the students themselves. Finally, we will examine the program in the context of how well it helps to address the challenges faced by educators today in meeting the demands of students in a world where the internet provides instant access to information. (author)

  19. The Deep River Science Academy: a unique and innovative program for engaging students in science

    International Nuclear Information System (INIS)

    For 28 years, the Deep River Science Academy (DRSA) has been offering high school students the opportunity to engage in the excitement and challenge of professional scientific research to help nurture their passion for science and to provide them with the experience and the knowledge to make informed decisions regarding possible future careers in the fields of science, technology, engineering, and mathematics (STEM). The venue for the DRSA program has been a six-week summer science camp where students, working in pairs under the guidance of a university undergraduate tutor, contribute directly to an on-going research program under the supervision of a professional scientist or engineer. This concept has been expanded in recent years to reach students in classrooms year round by engaging students via the internet over a 12-week term in a series of interactive teaching sessions based on an on-going research project. Although the research projects for the summer program are offered primarily from the laboratories of Atomic Energy of Canada Limited at its Chalk River Laboratories site, projects for the year-round program can be based, in principle, in laboratories at universities and other research institutes located anywhere in Canada. This paper will describe the program in more detail using examples illustrating how the students become engaged in the research and the sorts of contributions they have been able to make over the years. The impact of the program on the students and the degree to which the DRSA has been able to meet its objective of encouraging students to choose careers in the fields of STEM and equipping them with the skills and experience to be successful will be assessed based on feedback from the students themselves. Finally, we will examine the program in the context of how well it helps to address the challenges faced by educators today in meeting the demands of students in a world where the internet provides instant access to information. (author)

  20. Determination of Background Uranium Concentration in the Snake River Plain Aquifer under the Idaho National Engineering and Environmental Laboratory's Radioactive Waste Management Complex

    Energy Technology Data Exchange (ETDEWEB)

    Molly K. Leecaster; L. Don Koeppen; Gail L. Olson

    2003-06-01

    Uranium occurs naturally in the environment and is also a contaminant that is disposed of at the Radioactive Waste Management Complex (RWMC) at the Idaho National Engineering and Environmental Laboratory. To determine whether uranium concentrations in the Snake River Plain Aquifer, which underlies the laboratory, are elevated as a result of migration of anthropogenic uranium from the Subsurface Disposal Area in the RWMC, uranium background concentrations are necessary. Guideline values are calculated for total uranium, 234U, 235U, and 238U from analytical results from up to five datasets. Three of the datasets include results of samples analyzed using isotope dilution thermal ionization mass spectrometry (ID-TIMS) and two of the datasets include results obtained using alpha spectrometry. All samples included in the statistical testing were collected from aquifer monitoring wells located within 10 miles of the RWMC. Results from ID-TIMS and alpha spectrometry are combined when the data are not statistically different. Guideline values for total uranium were calculated using four of the datasets, while guideline values for 234U were calculated using only the alpha spectrometry results (2 datasets). Data from all five datasets were used to calculate 238U guideline values. No limit is calculated for 235U because the ID-TIMS results are not useful for comparison with routine monitoring data, and the alpha spectrometry results are too close to the detection limit to be deemed accurate or reliable for calculating a 235U guideline value. All guideline values presented represent the upper 95% coverage 95% confidence tolerance limits for background concentration. If a future monitoring result is above this guideline, then the exceedance will be noted in the quarterly monitoring report and assessed with respect to other aquifer information. The guidelines (tolerance limits) for total U, 234U, and 238U are 2.75 pCi/L, 1.92 pCi/L, and 0.90 pCi/L, respectively.

  1. Influence of clay and silica on permeability and capillary entry pressure of chalk reservoirs in the North Sea

    DEFF Research Database (Denmark)

    Røgen, Birte; Fabricius, Ida Lykke

    2002-01-01

    The permeability and capillary entry pressure of chalk reservoirs are controlled by their porosity and specific surface area. Measured permeabilities are in the range 0.025-5.3 mD and are successfully predicted by use of the Kozeny equation. In this paper we focus on the factors that control spec...

  2. Estimation of groundwater recharge to chalk and sandstone aquifers using simple soil models

    Science.gov (United States)

    Ragab, R.; Finch, J.; Harding, R.

    1997-03-01

    On the assumption that the water draining below the root zone is potentially available for groundwater recharge, two current UK methods for estimating annual groundwater recharge have been compared with a new soil model using data from four sites under permanent grass in the UK: two sites representative of the Chalk aquifer at Bridgest Farm (Hampshire) and Fleam Dyke (Cambridgeshire), and two sites on the Triassic sandstone at Bicton College (Devon) and Bacon Hall (Shropshire). A Four Root Layers Model (FRLM), the Penman-Grindley model and the UK Meteorological Office Rainfall and Evaporation Calculation System (MORECS) were used. The new soil model was run with potential evaporation as input both from the MORECS and from the Penman-Monteith equation. The models were run for the Chalk sites both with and without a bypass flow of 15% of rainfall. Bypass was not considered for the sandstone sites. The performance of the models was tested against neutron probes measurements of soil moisture deficits. In addition, the annual groundwater recharge estimated from the models was compared with the published values obtained from the 'zero flux plane' method. Generally, the Penman-Grindley model was more successful in predicting the time for soil to return to its field capacity than in predicting the magnitude of the soil moisture deficit. The annual groundwater recharge was predicted with reasonable accuracy. The MORECS relatively tended to overestimate the soil moisture deficits and to delay the time at which the soil returns to its field capacity. The consequences were underestimates of annual groundwater recharge, owing either to the higher values of potential evaporation calculated from the MORECS or tothe high available water capacity values associated with the soils under consideration. The new soil model (FRLM) predicts the soil moisture deficits successfully and hence is reliable in estimating the annual groundwater recharge. The model is capable of doing this with

  3. Characterisation of Laboratory-produced CANDU(r)-like workplace neutron fields

    International Nuclear Information System (INIS)

    Two neutron fields were produced in the Neutron Irradiation Facility (NIF) at the Chalk River Laboratories of the Atomic Energy of Canada Ltd. by direction (d,D) neutrons from a 150 kV neutron generator through a specially designed moderator assembly. Bonner sphere and proton recoil spectrometry systems were used to characterise these fields to determine whether they were CANDU(r)-like, i.e. whether they resembled neutron fields found in workplaces around pressurised heavy-water moderated power reactors such as CANDU(r) reactors. Similarities were found between the distributions in energy of neutron fluence and ambient dose equivalent of the neutron fields produced in the NIF and those measured previously in power plants. In addition, there was agreement between theoretical (Monte Carlo) data and measured data, thereby validating continued use of Monte Carlo modelling for field characterisations in the NIF. The CANDU(r)-like fields add to the repertoire of neutron fields available in the NIF and are expected to be useful for evaluating neutron dosemeters. (author)

  4. Geologic Controls of Hydraulic Conductivity in the Snake River Plain Aquifer At and Near the Idaho National Engineering and Environmental Laboratory, Idaho

    Energy Technology Data Exchange (ETDEWEB)

    S. R. Anderson; M. A. Kuntz; L. C. Davis

    1999-02-01

    The effective hydraulic conductivity of basalt and interbedded sediment that compose the Snake River Plain aquifer at and near the Idaho National Engineering and Environmental Laboratory (INEEL) ranges from about 1.0x10 -2 to 3.2x10 4 feet per day (ft/d). This six-order-of-magnitude range of hydraulic conductivity was estimated from single-well aquifer tests in 114 wells, and is attributed mainly to the physical characteristics and distribution of basalt flows and dikes. Hydraulic conductivity is greatest in thin pahoehoe flows and near-vent volcanic deposits. Hydraulic conductivity is least in flows and deposits cut by dikes. Estimates of hydraulic conductivity at and near the INEEL are similar to those measured in similar volcanic settings in Hawaii. The largest variety of rock types and the greatest range of hydraulic conductivity are in volcanic rift zones, which are characterized by numerous aligned volcanic vents and fissures related to underlying dikes. Three broad categories of hydraulic conductivity corresponding to six general types of geologic controls can be inferred from the distribution of wells and vent corridors. Hydraulic conductivity of basalt flows probably is increased by localized fissures and coarse mixtures of interbedded sediment, scoria, and basalt rubble. Hydraulic conductivity of basalt flows is decreased locally by abundant alteration minerals of probable hydrothermal origin. Hydraulic conductivity varies as much as six orders of magnitude in a single vent corridor and varies from three to five orders of magnitude within distances of 500 to 1,000 feet. Abrupt changes in hydraulic conductivity over short distances suggest the presence of preferential pathways and local barriers that may greatly affect the movement of ground water and the dispersion of radioactive and chemical wastes downgradient from points of waste disposal.

  5. An update of hydrologic conditions and distribution of selected constituents in water, Snake River Plain aquifer and perched groundwater zones, Idaho National Laboratory, Idaho, emphasis 2006-08

    Science.gov (United States)

    Davis, Linda C.

    2010-01-01

    Since 1952, radiochemical and chemical wastewater discharged to infiltration ponds (also called percolation ponds), evaporation ponds, and disposal wells at the Idaho National Laboratory (INL) has affected water quality in the eastern Snake River Plain aquifer and perched groundwater zones underlying the INL. The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, maintains groundwater monitoring networks at the INL to determine hydrologic trends, and to delineate the movement of radiochemical and chemical wastes in the aquifer and in perched groundwater zones. This report presents an analysis of water-level and water-quality data collected from aquifer and perched groundwater wells in the USGS groundwater monitoring networks during 2006-08. Water in the Snake River Plain aquifer primarily moves through fractures and interflow zones in basalt, generally flows southwestward, and eventually discharges at springs along the Snake River. The aquifer primarily is recharged from infiltration of irrigation water, infiltration of streamflow, groundwater inflow from adjoining mountain drainage basins, and infiltration of precipitation. From March-May 2005 to March-May 2008, water levels in wells generally remained constant or rose slightly in the southwestern corner of the INL. Water levels declined in the central and northern parts of the INL. The declines ranged from about 1 to 3 feet in the central part of the INL, to as much as 9 feet in the northern part of the INL. Water levels in perched groundwater wells around the Advanced Test Reactor Complex (ATRC) also declined. Detectable concentrations of radiochemical constituents in water samples from wells in the Snake River Plain aquifer at the INL generally decreased or remained constant during 2006-08. Decreases in concentrations were attributed to decreased rates of radioactive-waste disposal, radioactive decay, changes in waste-disposal methods, and dilution from recharge and underflow. In April

  6. Water temperatures within spawning beds in two chalk streams and implications for salmonid egg development

    Science.gov (United States)

    Acornley, R. M.

    1999-02-01

    Water temperatures within brown trout (Salmo trutta L.) spawning gravels were measured in two Hampshire chalk streams from October 1995 to April 1996 inclusive. During the winter, mean intra-gravel water temperatures were higher than those in the stream, and increased with depth in the gravel bed. The amplitude of diel fluctuations in water temperature decreased with depth in the gravel bed, although diel fluctuations were still evident at a depth of 30 cm. Differences in intra-gravel temperature gradients between the two study sites were attributed to differences in the amplitude of stream water temperature fluctuations and there was no evidence that either of the study sites were located in zones of upwelling groundwater. Published equations are used to predict, from temperature, the timing of important stages in the development of brown trout embryos (eyeing, hatching and emergence) for eggs spawned in the autumn and winter and buried at different depths in the gravel bed.

  7. Isotope and dissolved gas evidence for nitrogen attenuation in landfill leachate dispersing into a chalk aquifer

    International Nuclear Information System (INIS)

    The authors present data for the chemical, stable isotope (13C/12C, 15N/14N and 34S/32S), and dissolved gas (N2, Ar, O2 and CH4) composition of groundwaters sampled in and around a landfill site in Cambridgeshire, England. Decomposition of 3 x 106 m3 of largely domestic waste, placed in unlined quarries, has given rise to the formation of an NH4-rich leachate dispersing as a plume into the surrounding Middle Chalk aquifer. In addition to identifying zones of methanogenesis and SO4 reduction, the data indicate processes of NH4 transformation by either assimilation or oxidation, and losses by formation of N2. Depending on the mixing ratio between leachate and background water, it may be possible to account for all NH4 loss by combined nitrification + denitrification in a system where there are abrupt temporal and spatial changes in redox conditions

  8. Multi isotopic tools to understand selenium origins in groundwaters of the Chalk aquifer in Northern France

    Science.gov (United States)

    Cary, Lise; Gourcy, Laurence; Benabderraziq, Hind; Elkhattabi, Jamal; Laurent, Alexandra; Négrel, Philippe

    2013-04-01

    Four field wells exploiting the Chalk aquifer supply Lille city in water. The little catchment area is submitted to quantitative and qualitative pressure from industrial, urban and agriculture origins. Selenium (Se) concentrations are often higher than EU standards (0.12 µmol.L-1) for potable drinking water and can reach 0.4 μmol.L-1 leading to exploitation restrictions. An integrated study was settled to determine the water sources and dynamics of elements, with a focus on Se, with the goal of managing both water quality and quantity. After a large chemical characterisation of the system, a monthly sampling campaign was held in 2012 in four wells and in the close Deûle channel. In situ physical and chemical parameters, chemical analysis of major and trace elements with a special focus on redox-sensitive elements including SeIV, SeVI, FeII, stable water isotopes (δ18O, δ2H) and δ34S and δ18O of sulphates measures were undertaken. The chemical composition of solids sampled at various depths at vicinity of the four wells was analysed. Se concentrations in groundwaters and in the solid phase vary significantly. In the northern part of the Ansereuilles north of the Deûle channel, where the highest Se concentrations in solids was found in a 13 m alluvial clay deposit above the chalk, a first main type of waters can be defined with the variable and locally highest Se concentrations (0.19 to 0.4 µmol.L-1), relatively high and stable sulphate concentrations (2.5 µmol/L), no nitrates, dissolved Fe and Mn, negative δ34S (around -20 ‰) and δ18O typical of evaporated waters. A second main type of waters can be described at Houplin, south of the Deûle channel, where the geological profile show less than 1 mg/kg of Se, with intermediate Se concentrations (0.1 to 0.2 µmol/L), variable nitrate concentrations (0.4 to 1.2 mmol/L), not quantified dissolved Fe and Mn, sulphate concentrations close to 1.5 mmol/L, variable negative δ34S (-8 to -24 ‰) and δ18O in the

  9. Tracking selenium behaviour in chalk aquifer (northern France): Sr and 34S-sulphates isotopes constraints.

    Science.gov (United States)

    Cary, Lise; Benabderraziq, Hind; Elkhattabi, Jamal; Parmentier, Marc; Gourcy, Laurence; Négrel, Philippe

    2014-05-01

    Groundwaters in parts of the Paris Basin (France) are facing increasing selenium (Se) contents that can exceed the drinking water limit of 10 μg/L according to the European Framework Directive in the field of water policy (2000/60/EC). To better understand the groundwater origins and the selenium dynamics, the water chemistry of the Chalk aquifer supplying drinkable water to Lille city was studied. This area is submitted to quantitative and qualitative pressure from industrial, urban and agriculture origins. An integrated study was settled to determine the water sources and dynamics of elements, with a focus on Se. After a large chemical characterisation of the groundwater chemistry in the four field wells, a monthly monitoring was held in four wells and in the Deûle channel. Chemical analysis of major and trace elements, stable isotopes (δ18O, δ2H), strontium isotopes, and δ34S and δ18O of sulphates were realised. The chemical composition of solids sampled at various depths at vicinity of the four wells was also analysed. The specific geochemical signature of groundwater as revealed by Sr isotopes, in addition to element concentrations ratios like Mg/Sr and Se/Sr, highlighted mixture of three main groundwaters bodies: (1) the upstream groundwaters in the recharge area with the most radiogenic 87Sr/86Sr isotopic signature; (2) the confined groundwaters with high Sr concentrations due to water-rock interactions and the lowest 87Sr/86Sr isotopic signature close to the one of the chalk in Paris and London basins; (3) the Se-rich formations of Tertiary and Quaternary. The contents of Se, mainly present as SeV I (and locally as SeIV ), displayed spatial and temporal disparities that can be explained by geological and hydrogeological conditions. Se-rich clayed sediments originating from the dismantling of Se-rich tertiary formations (i.e. Ypresian) overlay the chalk formation and can be found in saturated conditions depending of the water table level. Oxidation of

  10. Water weakening of chalk explaied from a fluid-solid friction factor

    DEFF Research Database (Denmark)

    Andreassen, Katrine Alling; Fabricius, Ida Lykke

    2010-01-01

    to the macroscale failure and pore collapse properties. The Biot critical frequency incorporates the porosity, permeability, fluid density and fluid viscosity, where the latter is highly temperature dependent – it does not include the applied sound velocity frequency. The listed parameters are usually determined......The hypothesis behind this paper proposal is that the Biot critical frequency can be used to characterize the water weakening phenomenon physically. The Biot critical frequency determines the transition from where an applied sound velocity on a saturated porous chalk is dominated by viscous forces...... were tested at temperatures from 20°C to 130°C with the following pore fluids: fresh water, synthetic seawater of different chemical compositions, methanol, glycol, and oil of varying viscosity. The data was evaluated according to failure lines and yield envelopes for all fluids and temperatures while...

  11. Upper Cretaceous chalk facies and depositional history recorded in the Mona-1 core, Mona Ridge, Danish North Sea

    Directory of Open Access Journals (Sweden)

    Finn Surlyk

    2011-12-01

    Full Text Available The 331 m long core from the Mona-1 well in the Danish North Sea spans almost the entire Upper Cretaceous Chalk Group but only about 10% of Late Cretaceous time is represented. The succession comprises 14 facies representing pelagic deposition, turbidity flow, and mass-transport processes, including mudflow, debris flow, and slumping. Pelagic deposits vary mainly in terms of the concentration of siliciclastic material, the trace-fossil assemblage, and the presence or ab¬sence of primary sedimentary structures. Pelagic sedimentation was probably punctuated by the deposition of thin turbidites, and the resultant deposits were thoroughly bioturbated if deposited during normal oxygenation at the sea floor. Periodic benthic dysoxia resulted in the preservation of primary structures, as represented by laminated chalk which consists of thin pelagic laminae alternating with thin turbidites. In addition to the thin turbidites in the laminated chalk, four dif¬ferent turbidite facies are interpreted as representing high- to low-energy flows. Clast-supported chalk conglomerates have previously not been differentiated from other turbidites, but are here interpreted to be directly related to the down-slope evolution of debris flows. Debris flows are rep¬resented by matrix-supported conglomerates, which form one of the most common facies in the succession. High-concentration, gravity-driven suspension flows passed into dilute visco-plastic flows during the final stages of deposition and resulted in the deposition of structureless chalks. Limited shear deformation produced distinct quasi-facies from which the precursor facies can be deduced, whereas intense or continued shear deformation produced a shear-banded quasi-facies from which the precursor facies cannot be deduced in all cases. A series of major slump packages (14–18 in total are interpreted, forming over 40% of the succession; debrites appear to be the most common precursor facies involved in

  12. Upper Cretaceous chalk facies and depositional history recorded in the Mona-1 core, Mona Ridge, Danish North Sea: Plate 1

    Directory of Open Access Journals (Sweden)

    Surlyk, Finn

    2011-12-01

    Full Text Available The 331 m long core from the Mona-1 well in the Danish North Sea spans almost the entire Upper Cretaceous Chalk Group but only about 10% of Late Cretaceous time is represented. The succession comprises 14 facies representing pelagic deposition, turbidity flow, and mass-transport processes, including mudflow, debris flow, and slumping. Pelagic deposits vary mainly in terms of the concentration of siliciclastic material, the trace-fossil assemblage, and the presence or ab¬sence of primary sedimentary structures. Pelagic sedimentation was probably punctuated by the deposition of thin turbidites, and the resultant deposits were thoroughly bioturbated if deposited during normal oxygenation at the sea floor. Periodic benthic dysoxia resulted in the preservation of primary structures, as represented by laminated chalk which consists of thin pelagic laminae alternating with thin turbidites. In addition to the thin turbidites in the laminated chalk, four dif¬ferent turbidite facies are interpreted as representing high- to low-energy flows. Clast-supported chalk conglomerates have previously not been differentiated from other turbidites, but are here interpreted to be directly related to the down-slope evolution of debris flows. Debris flows are rep¬resented by matrix-supported conglomerates, which form one of the most common facies in the succession. High-concentration, gravity-driven suspension flows passed into dilute visco-plastic flows during the final stages of deposition and resulted in the deposition of structureless chalks. Limited shear deformation produced distinct quasi-facies from which the precursor facies can be deduced, whereas intense or continued shear deformation produced a shear-banded quasi-facies from which the precursor facies cannot be deduced in all cases. A series of major slump packages (14–18 in total are interpreted, forming over 40% of the succession; debrites appear to be the most common precursor facies involved in

  13. Age dating ground water by use of chlorofluorocarbons (CCl3F and CCl2F2), and distribution of chlorofluorocarbons in the unsaturated zone, Snake River Plain aquifer, Idaho National Engineering Laboratory, Idaho

    International Nuclear Information System (INIS)

    Detectable concentrations of chlorofluorocarbons (CFC's) were observed in ground water and unsaturated-zone air at the Idaho National Engineering Laboratory (INEL) and vicinity. The recharge ages of waters were determined to be from 4 to more than 50 years on the basis of CFC concentrations and other environmental data; most ground waters have ages of 14 to 30 years. These results indicate that young ground water was added at various locations to the older regional ground water (greater than 50 years) within and outside the INEL boundaries. The wells drilled into the Snake River Plain aquifer at INEL sampled mainly this local recharge. The Big Lost River, Birch Creek, the Little Lost River, and the Mud Lake-Terreton area appear to be major sources of recharge of the Snake River Plain aquifer at INEL. An average recharge temperature of 9.7±1.3 degrees C (degrees Celsius) was calculated from dissolved nitrogen and argon concentrations in the ground waters, a temperature that is similar to the mean annual soil temperature of 9 degrees C measured at INEL. This similarity indicates that the aquifer was recharged at INEL and not at higher elevations that would have cooler soil temperatures than INEL. Soil-gas concentrations at Test Area North (TAN) are explained by diffusion theory

  14. Dichloroethene and Vinyl Chloride Degradation Potential in Wetland Sediments at Twin Lakes and Pen Branch, Savannah River National Laboratory, South Carolina

    Science.gov (United States)

    Bradley, Paul M.

    2007-01-01

    A series of 14C-radiotracer-based microcosm experiments was conducted to assess the mechanisms and products of degradation of dichloroethene (DCE) and vinyl chloride (VC) in wetland sediments at the Department of Energy (DOE) Savannah River National Laboratory. This project investigated the potential for biotic and abiotic DCE and VC degradation in wetland sediments from the Twin Lakes area of the C-BRP investigative unit and from the portion of Pen Branch located directly down gradient from the CMP investigative unit. Substantial degradation of [1,2-14C] DCE and [1,2-14C] VC to 14CO2 was observed in all viable sediment microcosms prepared under oxic conditions. These results indicate that microbial mineralization processes, involving direct oxidation or cometabolic oxidation, are the primary mechanisms of DCE and VC biodegradation in Twin Lake and Pen Branch sediments under oxic conditions. Substantial degradation of [1,2-14C] DCE and [1,2-14C] VC was observed in all viable sediment microcosms incubated under anoxic conditions. Production of 14CO2 was observed in all sediment microcosms under anoxic conditions. In general, the accumulation of mineralization products (14CO2 and 14CH4) was comparable to the accumulation of those reduced daughter products (14C-VC, 14C-ethene or 14C-ethane) traditionally identified with chloroethene reductive dechlorination. These results indicate that microbial mineralization processes can be an important component of DCE and VC degradation in Twin Lake and Pen Branch sediments under anoxic conditions. These results demonstrate that an evaluation of the efficiency of in situ DCE and VC biodegradation in Twin Lakes and Pen Branch that is based solely on the observed accumulation of reduced daughter products may underestimate substantially the total extent of contaminant biodegradation and, thus, the contribution of biodegradation to overall contaminant attenuation. No evidence of abiotic degradation of [1,2-14C] DCE or [1,2-14C] VC

  15. DEMONSTRATION SOLIDIFICATION TESTS CONDUCTED ON RADIOACTIVELY CONTAMINATED ORGANIC LIQUIDS AT THE AECL WHITESHELL LABORATORIES

    International Nuclear Information System (INIS)

    The AECL, Whiteshell Laboratory (WL) near Pinawa Manitoba, Canada, was established in the early 1960's to carry out AECL research and development activities for higher temperature versions of the CANDU(regsign) reactor. The initial focus of the research program was the Whiteshell Reactor-1 (WR-1) Organic Cooled Reactor (OCR) that began operation in 1965. The OCR program was discontinued in the early 1970's in favor of the successful heavy-water-cooled CANDU system. WR-1 continued to operate until 1985 in support of AECL nuclear research programs. A consequence of the Federal government's recent program review process was AECL's business decision to discontinue research programs and operations at the Whiteshell Laboratories and to consolidate its' activities at the Chalk River Laboratories. As a result, AECL received government concurrence in 1998 to proceed to plan actions to achieve closure of WL. The planning actions now in progress address the need to safely and effectively transition the WL site from an operational state, in support of AECL's business, to a shutdown and decommissioned state that meets the regulatory requirements for a licensed nuclear site. The decommissioning program that will be required at WL is unique within AECL and Canada since it will need to address the entire research site rather than individual facilities declared redundant. Accordingly, the site nuclear facilities are being systematically placed in a safe shutdown state and planning for the decommissioning work to place the facilities in a secure monitoring and surveillance state is in progress. One aspect of the shutdown activities is to deal with the legacy of radioactively contaminated organic liquid wastes. Use of a polymer powder to solidify these organic wastes was identified as one possibility for improved interim storage of this material pending final disposition

  16. The use of resistivity and gamma logging in lithostratigraphical studies of the chalk in Lincolnshire and South Humberside

    International Nuclear Information System (INIS)

    Electrical resistivity and natural gamma logs obtained from 70 boreholes in Lincolnshire and South Humberside can be interpreted in terms of lithology and show excellent agreement with the detailed lithostratigraphical divisions of the Chalk, obtained by Wood and Smith (1978) from the study of surface exposures. As, to the best of our knowledge, this sequence is complete, for the first time a direct correlation between continuous borehole logs and a detailed lithostratigraphical succession is possible. Important marl bands and some erosion surfaces and flint bands can be identified on the resistivity and gamma logs and traced over most of the study area. Stratigraphical positions of the logged boreholes can be determined and formation thicknesses measured. This information has enabled the construction of an accurate contour map of the elevation of the base of the Chalk and the eastward extension of the Caistor Monocline has been identified. (author)

  17. Changes in Specific Surface as observed by NMR, caused by saturation of Chalk with porewater bearing divalent Ions

    DEFF Research Database (Denmark)

    Katika, Konstantina; Addassi, Mouadh; Alam, Mohammad Monzurul;

    2014-01-01

    Nuclear Magnetic Resonance (NMR) spectrometry has proved to be a good technique for determining the petrophysical properties of reservoir rocks; such as porosity and pore size distribution. We investigated how pore water rich in divalent ions affect the NMR signal from chalk with two different...... depositional textures. We compared two cases. The first experiments on outcrop chalk with high salinity brines showed that saturation with divalent ions (Mg2+,Ca2+and SO42-) cause major shifts in the T2 distribution curve, probably due to precipitation in the pore space. In a second set of experiments, fluid......-to-volume ratio of the pore space. The results of this work could benefit the ongoing study on the optimization of the water composition for Enhanced Oil Recovery (EOR) methods and shed light on how it can affect the mechanical and physical properties of the rock....

  18. PowerPoint or chalk and talk: Perceptions of medical students versus dental students in a medical college in India

    OpenAIRE

    Vikas Seth; Prerna Upadhyaya; Mushtaq Ahmad; et al, ...

    2010-01-01

    Vikas Seth, Prerna Upadhyaya, Mushtaq Ahmad, Vijay MogheDepartment of Pharmacology, Mahatma Gandhi Medical College, Jaipur, Rajasthan, IndiaPurpose: To assess students’ perceptions of the impact of PowerPoint (PPT) presentations in lectures in comparison to the traditional chalk and talk method and lectures using ­transparencies and overhead projector (TOHP). The study analyzes the preferences for teaching aids of medical students versus dental students.Methods: Second year ...

  19. Mass-transport deposits and reservoir quality of Upper Cretaceous Chalk within the German Central Graben, North Sea

    Science.gov (United States)

    Arfai, Jashar; Lutz, Rüdiger; Franke, Dieter; Gaedicke, Christoph; Kley, Jonas

    2016-04-01

    The architecture of intra-chalk deposits in the `Entenschnabel' area of the German North Sea is studied based on 3D seismic data. Adapted from seismic reflection characteristics, four types of mass-transport deposits (MTDs) are distinguished, i.e. slumps, slides, channels and frontal splay deposits. The development of these systems can be linked to inversion tectonics and halotectonic movements of Zechstein salt. Tectonic uplift is interpreted to have caused repeated tilting of the sea floor. This triggered large-scale slump deposition during Turonian-Santonian times. Slump deposits are characterised by chaotic reflection patterns interpreted to result from significant stratal distortion. The south-eastern study area is characterised by a large-scale frontal splay complex. This comprises a network of shallow channel systems arranged in a distributive pattern. Several slide complexes are observed near the Top Chalk in Maastrichtian and Danian sediments. These slides are commonly associated with large incisions into the sediments below. Best reservoir properties with high producible porosities are found in the reworked chalk strata, e.g. Danish North Sea, therefore MTDs detected in the study area are regarded as potential hydrocarbon reservoirs and considered as exploration targets.

  20. Determination of transmissivity and dispersion in a confined chalk aquifer by simulation of field experiments with three tracers

    International Nuclear Information System (INIS)

    Storage and repumping of thermal energy in chalk aquifers during periods of surplus and deficit production respectively might be an economically feasible method to meet man's need for heating. To be able to evaluate the temporal and spatial variations of thermal energy transfer between water, which mainly flows in the chalk fissures, and the chalk matrix itself it is necessary to know the transmissivity and dispersion parameters of the aquifer. Based on this background, field tests with pumping of water and tracers have been carried out as shown. The fissured chalk aquifer of magnitude H = 16 m is confined by almost impervious top and bottom layers. Two wells with distance L = 101 m were established. A steady flow with Q1 Q2 = 10.9 m3/h was established within a period of 24 h. The radioactive tracers 3H and 82Br and the fluorescent tracer R-WT (rhodamine-water tracer) were injected at known concentrations within a period of 5 min. At time = 24 h valve V0 was opened and V2 closed and within the following 320 h a single well repumping (Q1 = -10.9 m3/h, Q2 = 0) and temporal detection of tracer concentrations were carried out until practically all concentrations were zero. The three concentration curves show a time to peak of about 12 h and a temporal distribution of the relative concentrations (peak concentration = 100% for all tracers) which is almost identical. The total repumped amount of tracer (with correction for radioactive decay) was 63%, 93% and 53% for 3H, 82Br and R-WT, respectively. The corresponding peak concentrations relative to injected concentrations were 1088, 1745 and 737 ppm. These data indicate a strong adsorption to the chalk matrix for R-WT and 3H but weak for 82Br. The simulation of measured concentration curves will be done by means of at least two models, M1-M2, which both include linear adsorption. With respect to permeability and dispersion M1 and M2 differ as follows: M1. Constant coefficients k and D for permeability and dispersion

  1. Contribution of piezometric measurement to knowledge and management of low water levels: examples on the chalk aquifer in the Champagne Ardennes region

    Science.gov (United States)

    Stollsteiner, P.; Bessiere, H.; Nicolas, J.; Allier, D.; Berthet, O.

    2015-04-01

    This article is based on a BRGM study on piezometric indicators, threshold values of discharge and groundwater levels for the assessment of potentially-exploitable water resources of chalky watersheds. A method for estimating low water levels based on groundwater levels is presented from three examples representing chalk aquifers with different cycles: annual, combined and interannual. The first is located in Picardy and the two others in the Champagne-Ardennes region. Piezometers with annual cycles, used in these examples, are supposed to be representative of the aquifer hydro-dynamics. Except for multi-annual systems, the analysis between discharge measurements at a hydrometric station and groundwater levels measured at a piezometer representative of the main aquifer, leads to relatively precise and satisfactory relationships within a chalky context. These relationships may be useful for monitoring, validation, extension or reconstruction of the low water flow data. On the one hand, they allow definition of the piezometric levels corresponding to the different alert thresholds of river discharges. On the other hand, they clarify the proportions of low surface water flow from runoff or drainage of the aquifer. Finally, these correlations give an assessment of the minimum flow for the coming weeks. However, these correlations cannot be used to optimize the value of the exploitable water resource because it seems to be difficult to integrate the value of the effective rainfall that could occur during the draining period. Moreover, in the case of multi-annual systems, the solution is to attempt a comprehensive system modelling and, if it is satisfactory, using the simulated values to get rid of parasites or running the model for forecasting purposes.

  2. Stratigraphy and palaeoceanography of upper Masstrichtian chalks, southern Danish Central Graben

    Energy Technology Data Exchange (ETDEWEB)

    Ineson, J.R.; Buchardt, B.; Lassen, Susanne; Rasmussen, Jan A.; Schioeler, P.; Schovsbo, N.H.; Sheldon, E.; Surlyk, F. [Geological Survey of Denmark and Greenland, Copenhagen (Denmark)

    2006-07-01

    Upper Maastrichtian chalks form important hydrocarbon reservoirs in the Danish sector of the North Sea and have been intensively studied, yet their lithological uniformity can frustrate attempts to develop a high-resolution stratigraphic subdivision and a genetic understanding of the factors controlling production and sedimentation of the pelagic carbonate ooze. Recent research into these topics, by means of a multidisciplinary study involving quantitative/semiquantitative palynology, micropalaeontology (nannofossils, foraminifers) and isotope geochemistry, integrated with detailed sedimentology. Two key wells were selected, the M-1OX well from the Dan Field and the E-5X well from the Tyra SE Field, based on the extensive core coverage in these wells and on their position in the southern part of the Danish Central Graben where evidence of large-scale resedimentation (and consequent stratigraphic complexity) is uncommon within the Maastrichtian section. This study concentrated on a number of palaeoceanographic signals that can be derived from the sedimentary record. Planktonic organisms, both phytoplankton (e.g. coccolithophores, some dinoflagellates) and zooplankton (e.g. foraminifers) provide a record of conditions in the upper watermasses, largely within the photic zone, while bottom conditions are indicated by epifaunal/infaunal organisms (e.g. benthic foraminifers) and bioturbation, and by the sedimentological evidence of depositional processes at the sea floor. (LN)

  3. Water recharge and solute transport through the vadose zone of fractured chalk under desert conditions

    International Nuclear Information System (INIS)

    In the present study the inferred mechanism of groundwater recharge and contamination was studied using tracer concentrations in the fractured vadose zone of the Avdat chalk. The results of this study are important for an evaluation of groundwater contamination from existing and planned facilities in the northern Negev desert in Israel. This study focused on the vicinity of the Ramat Hovav industrial chemical complex in the northern Negev, which also includes the national site for hazardous waste. Water recharge and solute migration rates were examined in five core holes and one borehole which penetrate the entire vadose zone and enabled the collection of rock samples for chemical and isotopic analyses, and an observation of fracture distribution with depth. Tritium profiles were used to estimate water percolation rates through the vadose zone, chloride profiles were used to assess the migration rate of nonreactive solutes, and bromide profiles were also used to evaluate the migration rate of nonreactive contaminants. Deuterium and oxygen 18 profiles were used to assess the evaporation of the infiltrating water at and near land surface

  4. Paleomagnetism of late Cretaceous and Eocene limestones and chalks from Haiti - tectonic interpretations

    Science.gov (United States)

    van Fossen, Mickey C.; Channell, James E. T.

    1988-06-01

    We have conducted a paleomagnetic study of limestones and chalks from Haiti which suggests that the island of Hispaniola is a composite of at least two tectonically independent blocks. Sampling sites are distributed among three widely separated localities, namely: Les Cayes (nine sites; 18.3°N. Latitude; 73.6°W. Longitude) and Beloc (five sites; 18.4°N. Latitude; 72.6°W. Longitude) which are located on the southern peninsula of Haiti, and a northern locality, Ennery (six sites; 19.5°N. Latitude; 72.5°W. Longitude). Stable magnetization components of dual polarity and moderately high blocking temperature were revealed through progressive thermal demagnetization of samples from all of the Beloc and Ennery sites, while seven of the nine Les Cayes sites possessed unstable magnetizations. Mean paleolatitudes calculated from Beloc and Ennery data show 8° of latitudinal separation that is of at least Eocene age. Pole positions (Beloc: 43.2°N. Latitude; 185.8°E. Longitude, α95=25.1° and Ennery: 66.1°N. Latitude; 31.3°E. Longitude, α95=19.7°) show both colatitudinal and angular discordance with the North American apparent polar wander path. Based on these disparities, we demonstrate that the implied tectonic displacements tend to support some aspects of previously published Caribbean plate tectonic models.

  5. A critical assessment of simple recharge models: application to the UK Chalk

    Directory of Open Access Journals (Sweden)

    A. M. Ireson

    2012-10-01

    Full Text Available A framework for the rigorous quantification of the timing and magnitude of groundwater recharge is proposed. This involves developing a physically based model for the flow processes in the unsaturated and saturated zones that is consistent with the conceptualisation of the system, and with field observations. Subsequently, the essential behaviour of this model is emulated using a simpler model that can be applied within operational groundwater models. We take a UK Chalk aquifer as a case study. Flow processes are simulated convincingly using a dual permeability, equivalent continuum, Richards' equation model, applied to a 2-D hillslope transect along which four monitoring wells recorded water levels in the unconfined aquifer. A simple conventional recharge model that has been widely used was calibrated to reproduce the water table response simulated by the physically based model. The performance in reproducing the water table was surprisingly good, given the known discrepancies between the actual processes and the model representation. However, comparisons of recharge fluxes simulated by each model highlighted problems with the recharge processes in the simple model. Specifically, artificial bypass flow events during the summer were compensating for recharge that should have come from slow, continual drainage of the unsaturated zone. Such a model may still be useful for assessment of groundwater resources on a monthly basis, under non-extreme climatic conditions. However, under extreme wet or dry conditions, or under a changed climate the predictive capacity of such models is likely to be inadequate.

  6. Summary record of the twenty-third meeting, (technical sessions), Chalk River, Canada, 27 Sep - 1 Oct 1982

    International Nuclear Information System (INIS)

    The technical sessions deal with advances in nuclear data measurements and newer facilities (with special attention paid to data for fission and fusion reactors); advances in nuclear data evaluations (regional activities and joint evaluated file); activities of nuclear data centres; report on recent NEA meetings; subcommittee reports

  7. Proceedings of the Fetal Dosimetry Workshop held in Chalk River, ON (Canada), 25-26 June 1991

    International Nuclear Information System (INIS)

    It is important to ensure adequate protection of the developing embryo or fetus in situations where the parent, usually the mother, is potentially exposed to radionuclides. An embryo or fetus can be exposed to ionizing radiation by external or internal sources. The dose from external sources can be assessed relatively easily. There is considerable uncertainty as to what the fetal doses are following maternal intakes, and whether low doses of radiation to the fetus cause childhood cancer. This workshop was held to help address these issues. Discussions centered in particular on the biokinetics of the distribution and retention of radionuclides in the fetus and newborn, effects of incorporated radionuclides in the embryo or fetus, metabolic and dosimetric models, and radioprotection considerations. Eleven papers were presented

  8. Installation of a cw radiofrequency quadrupole accelerator at Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Chalk River Laboratories (CRL) has had a long history of cw proton beam development for production of intense neutron sources and fissile fuel breeders. In 1986 CRL and Los Alamos National Laboratory (LANL) entered into a collaborative effort to establish a base technologies program for the development of a cw radiofrequency quadrupole (RFQ). The initial cw RFQ design had 50-keV proton injection energy with 600-keV output energy. The 75-mA design current at 600-keV beam energy was obtained in 1990. Subsequently, the RFQ output energy was increased to 1250 keV by replacing the RFQ vanes, still maintaining the 75-m A design current. A new 250-kW cw klystrode rf power source at 267-MHz was installed at CRL. By April of 1993, 55-mA proton beams had been accelerated to 1250 keV. Concurrent developments were taking place on proton source development and on 50-keV low-energy beam transport (LEBT) systems. Development of a dc, high-proton fraction (≥ 70%) microwave ion source led to utilization of a single-solenoid RFQ direct injection scheme. It was decided to continue this cw RFQ demonstration project at Los Alamos when the CRL project was terminated in April 1993. The LANL goals are to find the current limit of the 1250-keV RFQ, better understand the beam transport properties through the single-solenoid focusing LEBT, continue the application of the cw klystrode tube technology to accelerators, and develop a two-solenoid LEBT which could be the front end of an Accelerator-Driven Transmutation Technologies (ADTT) linear accelerator

  9. Savannah River Site Environmental Implentation Plan

    International Nuclear Information System (INIS)

    This report describes the organizational responsibilities for the Savannah River Site Environmental program. Operations, Engineering and projects, Environment, safety, and health, Quality assurance, and the Savannah River Laboratory are described

  10. Geologic feasibility of selected chalk-bearing sequences within the conterminous United States with regard to siting of radioactive-waste repositories

    Energy Technology Data Exchange (ETDEWEB)

    Gonzales, S.

    1975-11-01

    Various geologic and hydrologic parameters are evaluated in relation to assessing the potential for repository storage of high-level radioactive wastes within several stratigraphic sequences dominated by chalks and chalky limestones. The former lithology is defined as a carbonate rock consisting mainly of very fine-grained particles of micritic calcite. Although chalks also contain coarser-grained particles such as shells of fossil foraminifera and non-calcitic minerals like quartz, most contain more than 90 percent micritic material. The latter represents broken fossil coccolith plates. The chalk-dominated formations discussed are exposed and underlie two different physiographic provinces which nevertheless display a general similarity in both being regions of extensive plains. The Niobrara Formation occurs mainly within the Great Plains province, while the Austin Chalk of Texas and the Selma Group of Alabama and Mississippi are located in the western and eastern Gulf Coastal Plain, respectively. The preliminary assessment is that chalk-bearing sequences show some promise and are deserving of added consideration and evaluation. Containment for hundreds of thousands of years would seem possible given certain assumptions. The most promising units from the three studied are the Niobrara Formation and Selma Group. Regional and local conditions make the Austin more suspect.

  11. The Green River Natural Analogue as A Field Laboratory To Study the Long-term Fate of CO2 in the subsurface

    OpenAIRE

    Busch, A.; Kampman, N.; Hangx, S.J.; Snippe, J.; Bickle, M.; Bertier, P.; Chapman, H.; Spiers, C. J.; Pijnenburg, R.; Samuelson, J; J. P. Evans; Maskell, A.; Nicholl, J; Pipich, V.; Di, Z.

    2014-01-01

    Understanding the long-term response of CO2 injected into porous reservoirs is one of the most important aspects to demonstrate safe and permanent storage. In order to provide quantitative constraints on the long-term impacts of CO2-charged fluids on the integrity of reservoir-caprock systems we recovered some 300m of core from a scientific drill hole through a natural CO2 reservoir, near Green River, Utah. We obtained geomechanical, mineralogical, geochemical, petrophysical and mineralogical...

  12. Characterising the vertical variations in hydraulic conductivity within the Chalk aquifer

    Science.gov (United States)

    Williams, A.; Bloomfield, J.; Griffiths, K.; Butler, A.

    2006-10-01

    SummaryVarious field methods have been used to examine and quantify the vertical variations in aquifer properties within the Chalk aquifer at a LOCAR site in Berkshire, UK. The site contains three 100 m open boreholes and three sets of two nested piezometers within an area of about 100 m 2. There is also an 86 m deep abstraction borehole about 40 m from the site. The techniques that have been used at the site include: geophysical logging, borehole imaging, packer testing, dilution testing and pumping tests. The packer test results show that the permeability of the aquifer varies by three orders of magnitude over the 70 m of tested material with a strongly non-linear decrease with depth below ground level. Comparison with the borehole images show that some of the highly permeable zones appear to be associated with obvious fractures. However, large fractures can be seen in zones which have much lower permeability while some highly permeable zones appear to be associated with poorly developed fractures. Single borehole dilution tests have shown that there are differences in flow velocity depth profiles over a few tens of meters across the site. These are inferred to be because the different boreholes, although of similar drilled depth and very close proximity, intersect slightly different parts of the fracture network and hence the groundwater flow system. In particular, a flowing feature at the base of one borehole is not intersected by the second, which is drilled from a slightly higher elevation. A dilution test carried out whilst the aquifer was being pumped shows that different fractures become active when the aquifer is stressed. This has implications for the interpretation of flow logs performed under pumping.

  13. Full-waveform inversion of cross-hole GPR data collected in a strongly heterogeneous chalk reservoir analogue with sharp permittivity and conductivity contrasts

    DEFF Research Database (Denmark)

    Keskinen, Johanna; Zibar, Majken Caroline Looms; Moreau, Julien;

    2014-01-01

    Chalk sediments form an important reservoir for groundwater onshore and for hydrocarbons in the Danish sector of the North Sea. Cross-hole Ground-penetrating radar (GPR) tomography is an efficient method to investigate subtle porosity variations in the chalk. Traditional ray-based inversion...... techniques provide models that are overly smooth and have relatively low resolution. We present preliminary results from full-waveform inversion of data collected in strongly heterogeneous chalk. The resolution of the tomograms has improved significantly compared to models obtained from travel......-time tomography. The new models also reflect the variability seen in 1D drill core analysis. The results indicate that full-waveform inversion is a well-suited inversion technique for high-resolution time-lapse-based flow characterization. Read More: http://library.seg.org/doi/abs/10.1190/segam2014-1199.1...

  14. Hydrochemical trends, palaeorecharge and groundwater ages in the fissured Chalk aquifer of the London and Berkshire Basins, UK

    International Nuclear Information System (INIS)

    The hydrochemical, radiochemical, stable isotope, 14C and dissolved noble gas composition of groundwaters has been determined along two profiles across the confined, fissured Chalk aquifer of the London Basin of southern England, and for selected sites in the adjacent Berkshire Basin. During downgradient flow in the London Basin aquifer, the groundwater chemistry is modified by water-rock interactions: congruent and incongruent reaction of the carbonate lithology resulting in enhanced Mg/Ca and Sr/Ca ratios and 13C contents with increased residence times; redox and ion exchange reactions; and towards the centre of the Basin, mixing with a residual saline connate water stored in the Chalk matrix. There is evidence from anomalous water chemistries for a component of vertical leakage from overlying Tertiary beds into the confined aquifer as a result of historical dewatering of the aquifer. Dissolved noble gas contents indicate the climate was up to 4.5C cooler than at present during recharge of the waters now found in the centres of both Basins; stable isotope (2H and 18O) depletions correspond to this recharge temperature change. For evolved waters having δ13 -8per thousand PDB a negative linear correlation is demonstrated between derived recharge temperatures and δ13C values, which is interpreted as mixing between relatively warm, light isotopic, fracture-borne waters and cooler stored waters of the matrix having a 13C signature more or less equilibrated with the Chalk. From geochemical (14C, 4He) age estimates, the abstracted water is interpreted as being either of wholly Holocene/post-Devensian glacial origin, or an admixture of Holocene and Late Pleistocene pre-glacial (cold stage interstadial) recharge. Devensian pleniglacial stage waters of the Last Glacial Maximum are not represented. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  15. Mechanical and chemical processes affecting the chalk during burial, insights from combined reflection seismics, well data and field work

    DEFF Research Database (Denmark)

    Moreau, Julien; Boussaha, Myriam; Thibault, Nicolas Rudolph;

    2014-01-01

    works have been performed with astronomical calibration based on stable isotope stratigraphy, wireline logs as well as several palaeontological proxies and detailed sedimentological analysis. Since a couple of decades, a specific kind of fractures has been described in the Chalk of Denmark, the so...... along the fractures (the compaction bands). The link between these different features has been realised thanks to the simultaneous analyses of large-scale geophysical data and small-scale core and field geological observations, providing a better understanding of the complex processes of lithification...

  16. Modelling relationships between habitat and dynamics of a wild brown trout (Salmo trutta L.) population in the River Piddle, Dorset, UK

    OpenAIRE

    Burrows, Andrew

    2006-01-01

    The status of "wild" brown trout (Salmo trutta, L. 1758) populations in the UK is increasingly giving cause for concern (Giles, 1989; Crisp; 1993). Declines in freshwater stocks are often associated with anthropogenic influences destructive to river channel structure and ecosystem function which are contributing to widespread loss of salmonid habitats (Crisp, 1989; White, 2002). Chalk streams are subject to considerable habitat degradation such that rehabilitation requires management actions ...

  17. River engineering

    NARCIS (Netherlands)

    De Vries, M.

    1993-01-01

    One dimension models - basic eauations, analytical models, numberical models. One dimensional models -suspended load, roughness and resistance of river beds. Solving river problems - tools, flood mitigation, bank protection.

  18. Laboratory and modeling studies in search of the critical hydrogen concentration

    International Nuclear Information System (INIS)

    The great success of hydrogen water chemistry (HWC) for primary coolant in nuclear power plants is due to the prevention of net radiolysis and to maintenance of the corrosion potential below -230 mV (SHE) where the rate of stress corrosion cracking is minimized. The critical hydrogen concentration or CHC has been defined as that concentration of excess H2 in primary coolant water, which prevents net water radiolysis via the chain reaction OH + H2 ↔H2O + H (1, -1) H + H2O2 → H2O + OH (2) The principle oxidizing free radical (OH) is thus converted into a reducing radical (H), oxidation products are reduced back to water, and the net result is no chemical change. A set of benchmark experiments at the U2 reactor in Chalk River have been reported in an extensive AECL report, which indicate that the CHC in this reactor is ca. 25 micro-molar. Using the review of yields and reaction rates set forth in another recent AECL report, the Chalk River experiments have been modelled in work at NNL, Harwell. The model was not able to successfully reproduce the experimental CHC, or the steady-state H2 concentrations (SSH2) in the absence of excess hydrogen. A sensitivity analysis of the entire model was carried out. Essentially three important variables have been found to dominate the result. Reaction rate (1) is overwhelmingly important in determining how much H2 is needed to accomplish the chain back-reaction. Almost with equal importance, the back reaction (-1) needs to be considered at 300 deg. C, but there is some uncertainty of its magnitude. Finally, the relative yields of radicals and molecular products (i.e. H2, H2O2 ) in particular H2:OH from the radiolysis are critical. Laboratory studies of hydrogenated water radiation chemistry have been carried out with a van de Graaff electron accelerator at Notre Dame Radiation Laboratory. Modelling of the hydrogen produced as a function of the hydrogen input, suggests that the reaction rate (-1) is ca. two times larger at 300

  19. Monitoring debris flow induced channel morphodynamics with terrestrial laser scanning, Chalk Cliffs, CO (Invited)

    Science.gov (United States)

    Wasklewicz, T. A.; Staley, D. M.

    2010-12-01

    Debris flows are important geomorphic agents in alpine drainages. They have been linked with channel initiation in headwater streams, connectivity of organic material and sediment through drainage basins, and as hazards to human development in and adjacent to steep watersheds. Debris flows also significantly alter channel morphometry at a variety of spatial scales. Of particular interest are topographic changes associated with multiple surge fronts within a debris flow as well as between several debris flows. An unnamed tributary stream to Chalk Creek, CO has over the last decade experienced one to four debris flow events annually. Four field sampling campaigns were conducted in the summer and fall of 2009. A Leica ScanStation 2, in conjunction with a robust local control network, were used to capture channel morphodynamics along five stream reaches prior to the debris flow season and after three debris flows. Point cloud data from the scanner permit the generation of two centimeter planimetric resolution digital terrain models (DTM). DTM-of-difference analyses and measures of slope, roughness, sediment transport volumes and channel dimensions were employed to detect spatial and temporal morphometric changes. The first debris flow occurred on unsaturated bed material and resulted in aggradation along 3 of the 5 reaches. One reach, a bedrock step, remained relatively unchanged, while the final reach saw significant erosion along boulder steps in the channel and an associated mass failure adjacent to the stream bank through this section. The second debris flow resulted in net aggradation along all of the reaches. The third and largest debris flow took place on saturated bed materials. The flow produced net erosion along all reaches. Significant channel changes were associated with the headward erosion of debris flow snouts and bank failures associated with undercutting of angle-of-repose slopes during debris flow erosion. Analysis of the potential relationships

  20. Radon levels in dwellings in chalk terrain. Development and analysis of distributional and causal models

    International Nuclear Information System (INIS)

    This thesis investigates the range, distribution and causes of high radon levels in dwellings in the Brighton area of Southeast England. Indoor radon levels were measured in more than 1000 homes. The results show that high radon levels can arise in an area previously considered to offer low radon potential from local geological sources. Climate and building-related factors were found to affect significantly the radon levels in dwellings. Multiple regression was used to determine the influence of the various factors on indoor radon levels and an empirical model develop to predict indoor radon levels. The radon hazard, independent of building-related effects, was determined for each surveyed location by adjusting the radon measurement to that expected on the ground floor of a 'model' dwelling. This standardised set of radon levels was entered into a geographical information system (GIS) and related to surface geology. The geometric mean radon level for each lithological unit was plotted to produce a radon hazard map for the area. The highest radon levels were found to be associated with the youngest Chalk Formations, particularly where they meet overlying Tertiary deposits, and with Clay-with-Flints Quaternary deposits in the area. The results were also converted to the radon activity equivalent to that expected from the NRPB's standard dual-detector dwelling survey method and analysed by lognormal modelling to estimate the proportion of dwellings likely to exceed the UK Action Level of 200 Bq/m3 for each lithological unit. The likely percentages of dwellings affected by radon thus obtained were mapped to lithological boundaries to produce a radon potential map. The radon hazard map and the empirical radon model facilitate the prediction of radon levels in dwellings of comparable construction and above similar geology and should further the understanding of the behaviour of radon gas in buildings to allow indoor radon concentrations to be controlled. The radon

  1. Hydrostratigraphy of the Snake River Plain aquifer beneath the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory: A preliminary report

    International Nuclear Information System (INIS)

    Geophysical logs for 6 wells which penetrate the Snake River Plain aquifer at the Radioactive Waste Management Complex (RWMC) were analyzed for preliminary information on the hydrostratigraphy. Using stratigraphic correlation of flow groups worked out by Anderson and Lewis (1989), and by Anderson, as well as gamma signatures of flows within these flow groups, correlation of individual flows is attempted. Within these flows, probable permeable zones, suggested by density and caliper logs, are identified, and zones of hydraulic connection are tentatively correlated. In order to understand the response of density and neutron logs in basalt, the geological characteristics are quantified for the 150-ft section of the well C1A core, from depth 550 to 710 ft. 9 refs., 4 figs

  2. Validity of chalk and bentonite application in soil and water on reducing the absorption of ratio-strontium and radio-cerium by crop

    International Nuclear Information System (INIS)

    Effects of the chalk and bentonite application in soil and surface water respectively on reducing the absorption of 89Sr and 141Ce by crop (especially in the edible part of crop) were studied by using isotope tracer techniques. The results showed that the specific activity of 89Sr in the ryegrass and Chinese cabbage could be decreased significantly by chalk application in the soil. The reduced ratio of 89Sr absorption of Chinese cabbage and ryegrass reached 77.7% and 35.2% respectively with the chalk application of 20 g/kg soil. The specific activity of 89Sr in ryegrass and Chinese cabbage followed obvious negative linear correlation with the quantity of application chalk in the soil. The specific activity of 141Ce in surface water, chaff and brown rice decreased by application bentonite in the surface water, which led to the lower accumulation of 141Ce in paddy. However, the absorption and accumulation of 141Ce in root and straw could not be changed. The specific activity of 141Ce in soil followed a negative exponential relation with depth of soil profile

  3. An accident involving transport of radioactive materials, Canada 1994 March

    International Nuclear Information System (INIS)

    AECL-Chalk River Laboratories (CRL) located at Chalk River, Ontario, routinely ships radioisotopes in bulk to Nordion International Inc. in Kanata, Ontario. On 1994 March 22, an AECL vehicle carrying three packages containing radioisotopes collided with a tractor trailer carrying steel, approximately 15 km east of the Chalk River Laboratories. The AECL-CRL emergency response plan was activated. A series of post-accident meetings were held to evaluate the effectiveness of the plan and to address any identified deficiencies. AECL-CRL is continuing to work towards addressing the identified deficiencies. (author). 2 figs

  4. The role of diagenisis in the hydrogeological stratification of carbonate aquifers: an example from the chalk at Fair Cross, Berkshire, UK

    Directory of Open Access Journals (Sweden)

    J. Bloomfield

    1997-01-01

    Full Text Available Carbonate rocks form important aquifers in many parts of the world and in north-west Europe the Chalk is a primary source of potable water. When flushed with relatively fresh groundwaters, the Chalk may undergo significant diagenetic alteration at relatively shallow depths resulting in a physically and hydrogeochemically stratified aquifer. Diagenetic affects may have important implications for the effective exploitable thickness of the Chalk aquifer and for water quality. In order to assess the affects of diagenesis on the properties of carbonate aquifers, matrix porosity, permeability, pore water and rock chemistry profiles have been analysed for a 300 m deep borehole through the Chalk at the western end of the London Basin. An abrupt change in the matrix porosity profile at 155 mbgl indicates a change in dominant mode of historic diagenesis from mechanical compaction above 155 mbgl to predominantly pressure solution compaction below 155 mbgl. Pore water and rock chemistry profiles also change abruptly across this depth interval, suggesting that the present day hydrogeology is controlled by historic diagenetic trends. Below 155 mbgl, pore waters are relatively saline and there is no evidence for groundwater flow; above 155 mbgl pore waters are relatively fresh and geochemical evidence for incon-gruent carbonate dissolution indicates contemporary groundwater circulation. Possible physical and chemical evolution paths for the Chalk at Fair Cross are discussed. The results provide a hydrogeological context for other studies of the long-term response of carbonate aquifers to base-line changes in sea-level and pore water chemistry and also enable studies with relatively short time-frames or of localized phenomena to be placed in the broader context of the evolution of carbonate aquifers.

  5. Sustainable irrigation Agriculture in the Tarim River Basin of Western Xinjiang Province--A proposal for the extablishment of a Salinity Laboratory of P. R. China%中国新疆塔里木河流域的可持续灌溉农业--关于建立中国国家盐渍化研究实验室的建议

    Institute of Scientific and Technical Information of China (English)

    约瑟夫·沙赫维特; 周政一; 徐曼

    2000-01-01

    Based on the background information and the personal impression obtained during a short visit to Tarim River basin, a few problems may be defined and a proposal is presented for establishing a salinity laboratiory in the Tarim river basin of Xinjiang. The problems encountered in the Tarim river basin can be grouped into four categories: (1) Salt reclamation through leaching and resalinization following irrigation; (2) Sodicity (alkalinity) problems; (3) Impermeable subsoil layers; (4) Irrigation water salinity. In order to ensure a sustainable irrigation agriculture in Xinjiang, the water utilization efficiency for both irngation and leaching will have to be improved. The solution for the existing problems and the prevention of future problems for sustainable production requires good quantitative information. It is considered that to establish a salinity laboratory in the Tarim River basin will be not only immediately applicable to Xinjiang' s salinity problems, but its results will be valuable also for other arid regions suffering from the similar problems in China.

  6. Vertical variation in groundwater chemistry inferred from fluid specific-conductance well logging of the Snake River Plain Basalt aquifer, Idaho National Engineering Laboratory, southeastern Idaho

    International Nuclear Information System (INIS)

    Well logging of electrical fluid specific conductance (Cs) shows that permeable zones yielding ground water to intrawell flows and the water columns in some wells at INEL have highly different chemistry, with as much as a two-fold variation in Cs. This suggests that dedicated-pump sampling of ground water in the aquifer may not be representative of the chemistry of the waste plumes migrating southwest of the nuclear facilities. Natural background Cs in basalt-aquifer ground water of this part of the Snake River Plain aquifer is less than 325μS/cm (microSiemans/cm), and total dissolved solids in mg/L units, (TDS) ∼ 0.6Cs. This relationship underestimates TDS for waters with chemical waste, when Cs is above 800 μS/cm. At well 59 near the ICPP water of 1115 μS/cm (∼6570+ mg/L TDS) enters the well from a permeable zone between 521 and 537 ft depth; the zone being 60 ft below the water level and water of 550 μS/cm. At the time of logging (9/14/93) the 1115/μS/cm water was flowing down the well, mixing with less concentrated waters and exciting at 600 or 624-ft depth. Waste water disposed of down the injection well at ICPP until 1984 was estimated to have a C5 of 1140 μS/cm, identical to the water detected in logging. 29 refs., 8 figs., 1 tab

  7. Mackenzie River Delta, Canada

    Science.gov (United States)

    2007-01-01

    The Mackenzie River in the Northwest Territories, Canada, with its headstreams the Peace and Finley, is the longest river in North America at 4241 km, and drains an area of 1,805,000 square km. The large marshy delta provides habitat for migrating Snow Geese, Tundra Swans, Brant, and other waterfowl. The estuary is a calving area for Beluga whales. The Mackenzie (previously the Disappointment River) was named after Alexander Mackenzie who travelled the river while trying to reach the Pacific in 1789. The image was acquired on August 4, 2005, covers an area of 55.8 x 55.8 km, and is located at 68.6 degrees north latitude, 134.7 degrees west longitude. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  8. Analysis and applications of microorganisms from a chalk oil reservoir in the North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Kaster, Krista Michelle

    2009-03-15

    Ekofisk a chalk oil reservoir in the Norwegian sector of the North Sea was found to harbour an active and diverse microbial community. Microbial actives may be deleterious in nature as in reservoir souring or maybe advantageous as in microbial enhanced oil recovery. The aim of this study was to characterise the microbial communities in the Ekofisk oil reservoir and to gain insight into the microbial mechanisms important for the a) control of reservoir souring, and b) which can be utilized in enhanced oil recovery. Produced water samples from the Ekofisk oil reservoir were analysed using both culture-dependent and -independent techniques. The Ekofisk microbial community was found to be dominated by thermophilic microorganisms many of which were capable of either sulphidogenic or methanogenic physiologies. They were similar to organisms that have been previously identified from oil reservoir fluids. The dominant organisms identified directly from the produced water samples had sequences similar to members of the genera Thermotoga, Caminicella, Thermoanaerobacter, Archaeoglobus, Thermococcus, and Methanobulbus. Enrichment cultures obtained from the produced water samples were dominated by sheathed rods. Sequence analyses of the cultures indicated predominance of the genera Petrotoga, Arcobacter, Archaeoglobus and Thermococcus. Reservoir souring caused by sulphide production due the activity of sulphate reducing prokaryotes (SRP) may be reduced by the injection of nitrate or nitrite. Nitrate or nitrite mitigates sulphide production either by the stimulation of nitrate reducing bacteria (NRB) through nitrate addition or via metabolic inhibition of the reduction of sulphite to sulphide by nitrite. Here we found that nitrate addition was ineffective at controlling souring whereas nitrite proved very effective at inhibiting sulphate reduction even at very low concentrations (0.25 mM - 1 mM) in both batch culture and bioreactor studies. To investigate microbial utilization

  9. High frequency seismic monitoring of debris flows at Chalk Cliffs (CO), USA

    Science.gov (United States)

    Coviello, Velio; Kean, Jason; Smith, Joel; Coe, Jeffrey; Arattano, Massimo; McCoy, Scott

    2015-04-01

    A growing number of studies adopt passive seismic monitoring techniques to investigate slope instabilities and landslide processes. These techniques are attractive and convenient because large areas can be monitored from a safe distance. This is particularly true when the phenomena under investigation are rapid and infrequent mass movements like debris flows. Different types of devices are used to monitor debris flow processes, but among them ground vibration detectors (GVDs) present several, specific advantages that encourage their use. These advantages include: (i) the possibility to be installed outside the channel bed, (ii) the high adaptability to different and harsh field conditions, and (iii) the capability to detect the debris flow front arrival tens of seconds earlier than contact and stage sensors. Ground vibration data can provide relevant information on the dynamics of debris flows such as timing and velocity of the main surges. However, the processing of the raw seismic signal is usually needed, both to obtain a more effective representation of waveforms and to decrease the amount of data that need to be recorded and analyzed. With this objective, the methods of Amplitude and Impulses are commonly adopted to transform the raw signal to a 1-Hz signal that allows for a more useful representation of the phenomenon. In that way, peaks and other features become more visible and comparable with data obtained from other monitoring devices. In this work, we present the first debris flows seismic recordings gathered in the Chalk Cliffs instrumented basin, central Colorado, USA. In May 2014, two 4.5-Hz, three-axial geophones were installed in the upper part of the catchment. Seismic data are sampled at 333 Hz and then recorded by a standalone recording unit. One geophone is directly installed on bedrock, the other one mounted on a 1-m boulder partially buried in colluvium. This latter sensor integrates a heavily instrumented cross-section consisting of a 225 cm2

  10. Progress report: Physical Sciences - TASCC Division, 1992 July 01 -December 31

    International Nuclear Information System (INIS)

    This report summarizes operations and research activities in the Nuclear Physics Branch and the TASCC Accelerators and Development Branch at Chalk River Laboratories during the last half of 1992. 27 figs., 10 tabs

  11. Progress report: Physical Sciences - Physics Division, 1992 July 01 -December 31

    International Nuclear Information System (INIS)

    This report summarizes operations and research activities in the Accelerator Physics, Neutron and Condensed Matter Science and Theoretical Physics branches at Chalk River Laboratories during the last half of 1992. 21 figs., 3 tabs

  12. Investigation of CO2 Enhanced Oil Recovery Using Dimensionless Groups in Wettability Modified Chalk and Sandstone Rocks

    Directory of Open Access Journals (Sweden)

    Vahid Alipour Tabrizy

    2014-01-01

    Full Text Available The paper addresses enhanced oil recovery in chalk and sandstone rocks by CO2 injection, with different wettability, porosity, and permeability as well as injection rate and flooding conditions. Results indicate that an increase in Bond number has a positive effect on oil recovery whereas for capillary number, there is a limit in which recovery is improving. This limit is estimated when the pressure drop by viscous force is approximately equal to the threshold balance between capillary and gravity forces. A dimensionless group is proposed that combines the effect of capillarity, injection rate, permeability, and CO2 diffusion on the oil recovery. Recovery from all experiments in this study and reported data in the literature shows a satisfactory relationship with the proposed group.

  13. Influence of coal mine tips on the chalk aquifer. Sampling methods for three dimensional sulphate infiltration study

    Energy Technology Data Exchange (ETDEWEB)

    Barrez, F.; Mania, J. [Polytech' Lille, Dept. Genie Civil, UMR CNRS 8107 (LML), 59 - Villeneuve d' Ascq (France); Mansy, J.L. [Lille-1 Univ., Lab. de Sedimentologie et de Geodynamique, UMR CNRS 8110 (PBDS), 59 - Villeneuve d' Ascq (France); Piwakowski, B. [Ecole Centrale de Lille, Groupe Electronique Acoustique IEMN-DOAE, UMR CNRS 8520, 59 - Villeneuve d' Ascq (France)

    2005-07-01

    The coal basin of the Nord-Pas-de-Calais region (France) shows a very strong deterioration of the Chalk aquifer quality. In order to better model the hydro-dynamism and to improve knowledge on the chemical interactions, sampling according to depth of the groundwater is undertaken. The low-flow sampling and the profiles of the in-situ physicochemical parameters allow the observation of various vertical heterogeneities of the aquifer. The areas where the coal mine tips are localised appear very interesting to study. The sulphates released by the pyrite oxidation allow a 'artificial tracing' and give a visualization of the flow as well as information on the implied chemical processes between the oxidizing and reducing zones. (authors)

  14. Radon hazard and risk in Sussex, England and the factors affecting radon levels in dwellings in chalk terrain

    International Nuclear Information System (INIS)

    A survey was undertaken of radon levels in 1013 dwellings in Sussex, UK. A number of dwellings were identified with high radon levels in an area previously considered to offer low radon risk from geological sources. Multiple regression was used to determine the relative influence of the various geographical and building-related factors on indoor radon levels. The radon hazard, independent of building-related effects, was determined for each surveyed location by standardising radon measurements to a 'model' dwelling. These were entered into a geographic information system and related to surface geology. The highest radon levels were found to be associated with the youngest Chalk formations, Tertiary deposits and Clay-with-flints Quaternary deposits in the area. Radon potentials were also determined for the area which can be used to estimate radon risk and assist in environmental planning and development control. (authors)

  15. Influence of coal mine tips on the chalk aquifer. Sampling methods for three dimensional sulphate infiltration study

    International Nuclear Information System (INIS)

    The coal basin of the Nord-Pas-de-Calais region (France) shows a very strong deterioration of the Chalk aquifer quality. In order to better model the hydro-dynamism and to improve knowledge on the chemical interactions, sampling according to depth of the groundwater is undertaken. The low-flow sampling and the profiles of the in-situ physicochemical parameters allow the observation of various vertical heterogeneities of the aquifer. The areas where the coal mine tips are localised appear very interesting to study. The sulphates released by the pyrite oxidation allow a 'artificial tracing' and give a visualization of the flow as well as information on the implied chemical processes between the oxidizing and reducing zones. (authors)

  16. Tilting oil-water contact in the chalk of Tyra Field as interpreted from capillary pressure data

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke; Rana, M.A.

    2010-01-01

    logging data in the remaining wells. A westerly dipping oil–water contact was found from logging data. Comparison of the depth-wise trends in normalized water saturation among the different wells indicates a regional pattern: in the western side of the field, the trends correspond to a situation of...... imbibition, where the free water level overlies an interval of residual oil, whereas in the eastern part of the field, the depth-wise trends in normalized water saturation correspond to a situation of drainage. The free water level apparently dips to the east due either to hydrodynamic action or to pressure......The Tyra Field in the central North Sea is located in Palaeogene and Upper Cretaceous chalk. It contains a natural gas zone underlain by an oil leg. Based on analysis of logs and core data from ten wells drilled prior to the field being put into production, normalized water saturation depth...

  17. 15N isotope biogeochemistry and natural denitrification process in groundwater: Application to the chalk aquifer of norther France

    International Nuclear Information System (INIS)

    The use of 15N natural isotope tracing in an aquifer contained within chalk rocks in northern France indicates that, under certain hydrogeological conditions, major denitrification occurs. At the boundary where the aquifer becomes confined, the nitrate concentrations decrease in the direction of groundwater flow accompanied by an exponential increase in 15N (expressed in δ15N) of the residual nitrate. This is characteristic of kinetic isotope effects, which accompany the reduction of the nitrate ion during denitrification. Hydrogeochemical and bacteriological observations confirm this process. Natural isotope tracing also permits this process to be distinguished from local dilution with nitrate-free water, which would entail a major drop in nitrate values without 15N isotopic enrichment. A model is proposed to explain the relatively small observed magnitude of the isotopic fractionation effect

  18. Fourth report on the Oak Ridge National Laboratory Biological Monitoring and Abatement Program for White Oak Creek Watershed and the Clinch River

    Energy Technology Data Exchange (ETDEWEB)

    Loar, J.M. [ed.

    1994-04-01

    In response to a condition of the National Pollutant Discharge Elimination System (NPDES) permit issued to Oak Ridge National Laboratory (ORNL) on April 1, 1986, a Biological Monitoring and Abatement Program (BMAP) was developed for White Oak Creek (WOC) and selected tributaries. BMAP currently consists of six major tasks that address both radiological and nonradiological contaminants in the aquatic and terrestrial environs on-site and the aquatic environs off-site. These tasks are (1) toxicity monitoring, (2) bioaccumulation monitoring of nonradiological contaminants in aquatic biota, (3) biological indicator studies, (4) instream ecological monitoring, (5) assessment of contaminants in the terrestrial environment, and (6) radioecology of WOC and White Oak Lake. The ecological characterization of the WOC watershed will provide baseline data that can be used to document the ecological effects of the water pollution control program and the remedial action program. The long-term nature of BMAP ensures that the effectiveness of remedial measures will be properly evaluated.

  19. HYDROMECHANICS LABORATORY

    Data.gov (United States)

    Federal Laboratory Consortium — Naval Academy Hydromechanics Laboratory The Naval Academy Hydromechanics Laboratory (NAHL) began operations in Rickover Hall in September 1976. The primary purpose...

  20. Experience in handling concentrated tritium

    International Nuclear Information System (INIS)

    The notes describe the experience in handling concentrated tritium in the hydrogen form accumulated in the Chalk River Nuclear Laboratories Tritium Laboratory. The techniques of box operation, pumping systems, hydriding and dehydriding operations, and analysis of tritium are discussed. Information on the Chalk River Tritium Extraction Plant is included as a collection of reprints of papers presented at the Dayton Meeting on Tritium Technology, 1985 April 30 - May 2

  1. Evaluation of well-purging effects on water-quality results for samples collected from the eastern Snake River Plain aquifer underlying the Idaho National Laboratory, Idaho

    Science.gov (United States)

    Knobel, LeRoy L.

    2006-01-01

    This report presents qualitative and quantitative comparisons of water-quality data from the Idaho National Laboratory, Idaho, to determine if the change from purging three wellbore volumes to one wellbore volume has a discernible effect on the comparability of the data. Historical water-quality data for 30 wells were visually compared to water-quality data collected after purging only 1 wellbore volume from the same wells. Of the 322 qualitatively examined constituent plots, 97.5 percent met 1 or more of the criteria established for determining data comparability. A simple statistical equation to determine if water-quality data collected from 28 wells at the INL with long purge times (after pumping 1 and 3 wellbore volumes of water) were statistically the same at the 95-percent confidence level indicated that 97.9 percent of 379 constituent pairs were equivalent. Comparability of water-quality data determined from both the qualitative (97.5 percent comparable) and quantitative (97.9 percent comparable) evaluations after purging 1 and 3 wellbore volumes of water indicates that the change from purging 3 to 1 wellbore volumes had no discernible effect on comparability of water-quality data at the INL. However, the qualitative evaluation was limited because only October-November 2003 data were available for comparison to historical data. This report was prepared by the U.S. Geological Survey in cooperation with the U.S. Department of Energy.

  2. Stratigraphy of the unsaturated zone and uppermost part of the Snake River Plain Aquifer at the Idaho Chemical Processing Plant and Test Reactors Area, Idaho National Engineering Laboratory, Idaho

    International Nuclear Information System (INIS)

    A complex sequence of basalt flows and sedimentary interbeds underlies the Idaho Chemical Processing Plant and Test Reactors Area at the Idaho National Engineering Laboratory in eastern Idaho. Wells drilled to a depth of 700 feet penetrate a sequence of 23 basalt-flow groups and 15 to 20 sedimentary interbeds that range in age from 200,000 to 640,000 years. The 23 flow groups consist of about 40 separate basalt flows and flow units. Each flow group is made up of one to three petrographically similar basalt flows that erupted from related source areas during periods of less than 200 years. Sedimentary interbeds consist of fluvial, lacustrine, and eolian deposits of clay, silt, sand, and gravel that accumulated during periods of volcanic inactivity ranging from thousands to hundreds of thousands of years. Multiple flow groups and sedimentary interbeds of similar age and source form seven composite stratigraphic units with distinct upper and lower contacts. Composite units older than 350,000 years were tilted, folded, and fractured by differential subsidence and uplift. Basalt and sediment of this sequence are unsaturated to a depth that ranges from 430 to 480 feet below land surface. Basalt and sediment in the lower part of the sequence are saturated and make up the uppermost part of the Snake River Plain aquifer. Stratigraphic relations in the lowermost part of the aquifer below a depth of 700 feet are uncertain. 23 refs., 22 figs., 1 tab

  3. Department of Energy Programmatic Spent Nuclear Fuel Management and Idaho National Engineering Laboratory Environmental Restoration and Waste Management Programs Draft Environmental Impact Statement. Volume 1, Appendix C, Savannah River Site Spent Nuclear Fuel Mangement Program

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    The US Department of Energy (DOE) is engaged in two related decision making processes concerning: (1) the transportation, receipt, processing, and storage of spent nuclear fuel (SNF) at the DOE Idaho National Engineering Laboratory (INEL) which will focus on the next 10 years; and (2) programmatic decisions on future spent nuclear fuel management which will emphasize the next 40 years. DOE is analyzing the environmental consequences of these spent nuclear fuel management actions in this two-volume Environmental Impact Statement (EIS). Volume 1 supports broad programmatic decisions that will have applicability across the DOE complex and describes in detail the purpose and need for this DOE action. Volume 2 is specific to actions at the INEL. This document, which limits its discussion to the Savannah River Site (SRS) spent nuclear fuel management program, supports Volume 1 of the EIS. Following the introduction, Chapter 2 contains background information related to the SRS and the framework of environmental regulations pertinent to spent nuclear fuel management. Chapter 3 identifies spent nuclear fuel management alternatives that DOE could implement at the SRS, and summarizes their potential environmental consequences. Chapter 4 describes the existing environmental resources of the SRS that spent nuclear fuel activities could affect. Chapter 5 analyzes in detail the environmental consequences of each spent nuclear fuel management alternative and describes cumulative impacts. The chapter also contains information on unavoidable adverse impacts, commitment of resources, short-term use of the environment and mitigation measures.

  4. Hydraulic Characteristics of Bedrock Constrictions and Evaluation of One- and Two-Dimensional Models of Flood Flow on the Big Lost River at the Idaho National Engineering and Environmental Laboratory, Idaho

    Science.gov (United States)

    Berenbrock, Charles; Rousseau, Joseph P.; Twining, Brian V.

    2007-01-01

    A 1.9-mile reach of the Big Lost River, between the Idaho National Engineering and Environmental Laboratory (INEEL) diversion dam and the Pioneer diversion structures, was investigated to evaluate the effects of streambed erosion and bedrock constrictions on model predictions of water-surface elevations. Two one-dimensional (1-D) models, a fixed-bed surface-water flow model (HEC-RAS) and a movable-bed surface-water flow and sediment-transport model (HEC-6), were used to evaluate these effects. The results of these models were compared to the results of a two-dimensional (2-D) fixed-bed model [Transient Inundation 2-Dimensional (TRIM2D)] that had previously been used to predict water-surface elevations for peak flows with sufficient stage and stream power to erode floodplain terrain features (Holocene inset terraces referred to as BLR#6 and BLR#8) dated at 300 to 500 years old, and an unmodified Pleistocene surface (referred to as the saddle area) dated at 10,000 years old; and to extend the period of record at the Big Lost River streamflow-gaging station near Arco for flood-frequency analyses. The extended record was used to estimate the magnitude of the 100-year flood and the magnitude of floods with return periods as long as 10,000 years. In most cases, the fixed-bed TRIM2D model simulated higher water-surface elevations, shallower flow depths, higher flow velocities, and higher stream powers than the fixed-bed HEC-RAS and movable-bed HEC-6 models for the same peak flows. The HEC-RAS model required flow increases of 83 percent [100 to 183 cubic meters per second (m3/s)], and 45 percent (100 to 145 m3/s) to match TRIM2D simulations of water-surface elevations at two paleoindicator sites that were used to determine peak flows (100 m3/s) with an estimated return period of 300 to 500 years; and an increase of 13 percent (150 to 169 m3/s) to match TRIM2D water-surface elevations at the saddle area that was used to establish the peak flow (150 m3/s) of a paleoflood

  5. Simulation of Flow and Long-Term Plutonium (Pu) Transport in the Vadose Zone at the Savannah River National Laboratory (SRNL)

    Science.gov (United States)

    Demirkanli, I.; Molz, F. J.; Kaplan, D. I.; Fjeld, R. A.; Serkiz, S. M.

    2006-05-01

    An improved understanding of flow and radionuclide transport in vadose zone sediments is fundamental to all types of future planning involving radioactive materials. One way to obtain such understanding is to perform long-term experimental studies of Pu transport in complex natural systems. With this in mind, a series of field experiments were initiated at the SRNL in the early 1980s. Lysimeters containing sources of different Pu oxidation states were placed in the shallow subsurface and left open to the natural environment for 2 to 11 years. At the end of the experiments, Pu activities were measured along vertical cores obtained from the lysimeters. Pu distributions were anomalous in nature, with transport from oxidized Pu sources being less than expected, and a small fraction of Pu from reduced sources moving more. Laboratory studies with lysimeter sediments suggested that surface-mediated, oxidation/reduction (redox) reactions could be responsible for the anomalous behavior, and this hypothesis is tested by performing both steady-state and transient Pu transport simulations that include retardation along with first-order redox reactions on mineral surfaces. Based on the simulations, we conclude that the surface-mediated, redox hypothesis is consistent with the observed downward Pu activity profiles in the experiments, and such profiles are captured well by a steady-state, net downward, flow model. (Discussion is presented as to why a steady model appears to work in a highly transient flow environment.) The redox model explains how Pu(V/VI) sources release activity that moves downward more slowly than expected based on adsorptive retardation alone, and how Pu(III/IV) sources result in a small fraction of activity that moves downward more rapidly than expected. The calibrated parameter values were robust and relatively well-defined throughout all four sets of simulations. Pu(V/VI) (i.e., oxidized Pu)retardation factors were about 15, and reduced Pu

  6. Contribution of piezometric measurement to knowledge and management of low water levels: examples on the chalk aquifer in the Champagne Ardennes region

    OpenAIRE

    Stollsteiner, P.; Bessiere, H.; Nicolas, J.; Allier, D.; Berthet, O.

    2015-01-01

    This article is based on a BRGM study on piezometric indicators, threshold values of discharge and groundwater levels for the assessment of potentially-exploitable water resources of chalky watersheds. A method for estimating low water levels based on groundwater levels is presented from three examples representing chalk aquifers with different cycles: annual, combined and interannual. The first is located in Picardy and the two others in the Champagne-Ardennes region. Piezometers with...

  7. Integrated seismic analysis of the Chalk Group in eastern Denmark—Implications for estimates of maximum palaeo-burial in southwest Scandinavia

    DEFF Research Database (Denmark)

    Nielsen, Lars; Boldreel, Lars Ole; Hansen, Thomas Mejer;

    2011-01-01

    The origin of the topography of southwest Scandinavia is subject to discussion. Analysis of borehole seismic velocity has formed the basis for interpretation of several hundred metres of Neogene uplift in parts of Denmark.Here, refraction seismic data constrain a 7.5km long P-wave velocity model of...... velocities are systematically higher than values of a chalk velocity curve determined in previous studies, and it is estimated that a significant part of the velocity anomaly may be explained by the presence of clay. The remaining velocity anomaly can be explained by 450–500m palaeo-burial of the Chalk Group....... The burial anomaly will be over-estimated by ~150–200m if the analysis is based on the average Chalk Group velocity and clay content is disregarded. Burial anomaly values of ~450–600m result if the strongest velocity contrast at ~600–650m depth is interpreted to be a result of diagenetic effects...

  8. Integrated seismic analysis of the Chalk Group in eastern Denmark—Implications for estimates of maximum palaeo-burial in southwest Scandinavia

    DEFF Research Database (Denmark)

    Nielsen, Lars; Boldreel, Lars Ole; Hansen, Thomas Mejer; Lykke-Andersen, Holger; Stemmerik, Lars; Surlyk, Finn; Thybo, Hans

    . The burial anomaly will be over-estimated by ~150–200m if the analysis is based on the average Chalk Group velocity and clay content is disregarded. Burial anomaly values of ~450–600m result if the strongest velocity contrast at ~600–650m depth is interpreted to be a result of diagenetic effects......The origin of the topography of southwest Scandinavia is subject to discussion. Analysis of borehole seismic velocity has formed the basis for interpretation of several hundred metres of Neogene uplift in parts of Denmark.Here, refraction seismic data constrain a 7.5km long P-wave velocity model of...... the Chalk Group below the Stevns peninsula, eastern part of the Danish Basin. The model contains four layers in the ~860m thick Chalk Group with mean velocities of 2.2km/s, 2.4km/s, 3.1km/s, and 3.9–4.3km/s. Sonic and gamma wireline log data from two cored boreholes represent the upper ~450m of the...

  9. Area balance and strain in an extensional fault system: Strategies for improved oil recovery in fractured chalk, Gilbertown Field, southwestern Alabama. Final report, March 1996--September 1998

    Energy Technology Data Exchange (ETDEWEB)

    Pashin, J.C.; Raymond, D.E.; Rindsberg, A.K.; Alabi, G.G.; Carroll, R.E.; Groshong, R.H.; Jin, G.

    1998-12-01

    This project was designed to analyze the structure of Mesozoic and Tertiary strata in Gilbertown Field and adjacent areas to suggest ways in which oil recovery can be improved. The Eutaw Formation comprises 7 major flow units and is dominated by low-resistivity, low-contrast play that is difficult to characterize quantitatively. Selma chalk produces strictly from fault-related fractures that were mineralized as warm fluid migrated from deep sources. Resistivity, dipmeter, and fracture identification logs corroborate that deformation is concentrated in the hanging-wall drag zones. New area balancing techniques were developed to characterize growth strata and confirm that strain is concentrated in hanging-wall drag zones. Curvature analysis indicates that the faults contain numerous fault bends that influence fracture distribution. Eutaw oil is produced strictly from footwall uplifts, whereas Selma oil is produced from fault-related fractures. Clay smear and mineralization may be significant trapping mechanisms in the Eutaw Formation. The critical seal for Selma reservoirs, by contrast, is where Tertiary clay in the hanging wall is juxtaposed with poorly fractured Selma chalk in the footwall. Gilbertown Field can be revitalized by infill drilling and recompletion of existing wells. Directional drilling may be a viable technique for recovering untapped oil from Selma chalk. Revitalization is now underway, and the first new production wells since 1985 are being drilled in the western part of the field.

  10. COMPARISON OF THE TRADITIONAL CHALK AND BOARD LECTURE SYSTEM VERSUS POWER POINT PRESENTATION AS A TEACHING TECHNIQUE FOR TEACHING GROSS ANATOMY TO THE FIRST PROFESSIONAL MEDICAL STUDENTS

    Directory of Open Access Journals (Sweden)

    Nusrat

    2015-02-01

    Full Text Available Traditionally and conventionally, gross anatomy is taught by lectures and cadaveric dissection and the lectures are taken with chalk and board (C&B or chalk and talk method in, India. But there is always a debate over the most effective method of lecture delivery. AIM : The aim of this study was to compare the role and effectiveness chalk and board method versus power point presentation ( S tudent’s perception as a lecture delivering method for teaching gross anatomy. METHODS: This was a questionnaire based study where 140 out of 150 first professional MBBS students of Medical College Jammu, were asked to fill anonymously a questionnaire about their perceptions of these two lecture delivery methods. The results were analyzed to see if there was any preference of students for any particular method. RESULTS: The majority of the medical students (90.7% preferred PPT presentations, while only 9.3% of students preferred the lectures using chalkboard method. CONCLUSION: Most of the students clearly preferred and accepted the use of PPT presentations, as compared to conventional board teaching for delivery method. So teaching gross anatomy should be carefully amalgamated with use of power point in lecture hall.

  11. Columbia River water quality monitoring

    International Nuclear Information System (INIS)

    Waste water from Hanford activities is discharged at eight points along the Hanford reach of the Columbia River. These discharges consist of backwash water from water intake screens, cooling water, river bank springs, water storage tank overflow, and fish laboratory waste water. Each discharge point is identified in an existing National Pollutant Discharge Elimination System (NPDES) permit issued by the EPA. Effluents from each of these outfalls are routinely monitored and reported by the operating contractors as required by their NPDES permits. Measurements of several Columbia River water quality parameters were conducted routinely during 1982 both upstream and downstream of the Hanford Site to monitor any effects on the river that may be attributable to Hanford discharges and to determine compliance with the Class A designation requirements. The measurements indicated that Hanford operations had a minimal, if any, impact on the quality of the Columbia River water

  12. Depth and temporal variations in water quality of the Snake River Plain aquifer in well USGS-59 near the Idaho Chemical Processing Plant at the Idaho National Engineering and Environmental Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Frederick, D.B. [Idaho INEL Oversight Program, Boise, ID (United States); Johnson, G.S. [Univ. of Idaho, Moscow, ID (United States). Dept. of Geology and Geological Engineering

    1997-03-01

    In-situ measurements of the specific conductance and temperature of ground water in the Snake River Plain aquifer were collected in observation well USGS-59 near the Idaho Chemical Processing Plant at the Idaho National Engineering and Environmental Laboratory. These parameters were monitored at various depths in the aquifer from October 1994 to August 1995. The specific conductance of ground water in well USGS-59, as measured in the borehole, ranged from about 450 to 900 {micro}S/cm at standard temperature (25 C). The pumping cycle of the production wells at the Idaho Chemical Processing Plant causes changes in borehole circulation patterns, and as a result the specific conductance of ground water at some depths in the well varies by up to 50% over a period of about 14 hours. However, these variations were not observed at all depths, or during each pumping cycle. The temperature of ground water in the well was typically between 12.8 and 13.8 C. The results of this study indicate that temporal variations in specific conductance of the ground water at this location are caused by an external stress on the aquifer--pumping of a production well approximately 4,000 feet away. These variations are believed to result from vertical stratification of water quality in the aquifer and a subsequent change in intrawell flow related to pumping. When sampling techniques that do not induce a stress on the aquifer (i.e., thief sampling) are used, knowledge of external stresses on the system at the time of sampling may aid in the interpretation of geochemical data.

  13. Depth and temporal variations in water quality of the Snake River Plain aquifer in well USGS-59 near the Idaho Chemical Processing Plant at the Idaho National Engineering and Environmental Laboratory

    International Nuclear Information System (INIS)

    In-situ measurements of the specific conductance and temperature of ground water in the Snake River Plain aquifer were collected in observation well USGS-59 near the Idaho Chemical Processing Plant at the Idaho National Engineering and Environmental Laboratory. These parameters were monitored at various depths in the aquifer from October 1994 to August 1995. The specific conductance of ground water in well USGS-59, as measured in the borehole, ranged from about 450 to 900 microS/cm at standard temperature (25 C). The pumping cycle of the production wells at the Idaho Chemical Processing Plant causes changes in borehole circulation patterns, and as a result the specific conductance of ground water at some depths in the well varies by up to 50% over a period of about 14 hours. However, these variations were not observed at all depths, or during each pumping cycle. The temperature of ground water in the well was typically between 12.8 and 13.8 C. The results of this study indicate that temporal variations in specific conductance of the ground water at this location are caused by an external stress on the aquifer--pumping of a production well approximately 4,000 feet away. These variations are believed to result from vertical stratification of water quality in the aquifer and a subsequent change in intrawell flow related to pumping. When sampling techniques that do not induce a stress on the aquifer (i.e., thief sampling) are used, knowledge of external stresses on the system at the time of sampling may aid in the interpretation of geochemical data

  14. Identification of a New Hesperornithiform from the Cretaceous Niobrara Chalk and Implications for Ecologic Diversity among Early Diving Birds.

    Directory of Open Access Journals (Sweden)

    Alyssa Bell

    Full Text Available The Smoky Hill Member of the Niobrara Chalk in Kansas (USA has yielded the remains of numerous members of the Hesperornithiformes, toothed diving birds from the late Early to Late Cretaceous. This study presents a new taxon of hesperornithiform from the Smoky Hill Member, Fumicollis hoffmani, the holotype of which is among the more complete hesperornithiform skeletons. Fumicollis has a unique combination of primitive (e.g. proximal and distal ends of femur not expanded, elongate pre-acetabular ilium, small and pyramidal patella and derived (e.g. dorsal ridge on metatarsal IV, plantarly-projected curve in the distal shaft of phalanx III:1 hesperornithiform characters, suggesting it was more specialized than small hesperornithiforms like Baptornis advenus but not as highly derived as the larger Hesperornis regalis. The identification of Fumicollis highlights once again the significant diversity of hesperornithiforms that existed in the Late Cretaceous Western Interior Seaway. This diversity points to the existence of a complex ecosystem, perhaps with a high degree of niche partitioning, as indicated by the varying degrees of diving specializations among these birds.

  15. Diagnosing hydrological limitations of a land surface model: application of JULES to a deep-groundwater chalk basin

    Science.gov (United States)

    Le Vine, N.; Butler, A.; McIntyre, N.; Jackson, C.

    2016-01-01

    Land surface models (LSMs) are prospective starting points to develop a global hyper-resolution model of the terrestrial water, energy, and biogeochemical cycles. However, there are some fundamental limitations of LSMs related to how meaningfully hydrological fluxes and stores are represented. A diagnostic approach to model evaluation and improvement is taken here that exploits hydrological expert knowledge to detect LSM inadequacies through consideration of the major behavioural functions of a hydrological system: overall water balance, vertical water redistribution in the unsaturated zone, temporal water redistribution, and spatial water redistribution over the catchment's groundwater and surface-water systems. Three types of information are utilized to improve the model's hydrology: (a) observations, (b) information about expected response from regionalized data, and (c) information from an independent physics-based model. The study considers the JULES (Joint UK Land Environmental Simulator) LSM applied to a deep-groundwater chalk catchment in the UK. The diagnosed hydrological limitations and the proposed ways to address them are indicative of the challenges faced while transitioning to a global high resolution model of the water cycle.

  16. Projecting impacts of climate change on hydrological conditions and biotic responses in a chalk valley riparian wetland

    Science.gov (United States)

    House, A. R.; Thompson, J. R.; Acreman, M. C.

    2016-03-01

    Projected changes in climate are likely to substantially impact wetland hydrological conditions that will in turn have implications for wetland ecology. Assessing ecohydrological impacts of climate change requires models that can accurately simulate water levels at the fine-scale resolution to which species and communities respond. Hydrological conditions within the Lambourn Observatory at Boxford, Berkshire, UK were simulated using the physically based, distributed model MIKE SHE, calibrated to contemporary surface and groundwater levels. The site is a 10 ha lowland riparian wetland where complex geological conditions and channel management exert strong influences on the hydrological regime. Projected changes in precipitation, potential evapotranspiration, channel discharge and groundwater level were derived from the UK Climate Projections 2009 ensemble of climate models for the 2080s under different scenarios. Hydrological impacts of climate change differ through the wetland over short distances depending on the degree of groundwater/surface-water interaction. Discrete areas of groundwater upwelling are associated with an exaggerated response of water levels to climate change compared to non-upwelling areas. These are coincident with regions where a weathered chalk layer, which otherwise separates two main aquifers, is absent. Simulated water levels were linked to requirements of the MG8 plant community and Desmoulin's whorl snail (Vertigo moulinsiana) for which the site is designated. Impacts on each are shown to differ spatially and in line with hydrological impacts. Differences in water level requirements for this vegetation community and single species highlight the need for separate management strategies in distinct areas of the wetland.

  17. An Update of Hydrologic Conditions and Distribution of Selected Constituents in Water, Snake River Plain Aquifer and Perched-Water Zones, Idaho National Laboratory, Idaho, Emphasis 2002-05

    Science.gov (United States)

    Davis, Linda C.

    2008-01-01

    Radiochemical and chemical wastewater discharged since 1952 to infiltration ponds, evaporation ponds, and disposal wells at the Idaho National Laboratory (INL) has affected water quality in the Snake River Plain aquifer and perched-water zones underlying the INL. The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, maintains ground-water monitoring networks at the INL to determine hydrologic trends, and to delineate the movement of radiochemical and chemical wastes in the aquifer and in perched-water zones. This report presents an analysis of water-level and water-quality data collected from aquifer and perched-water wells in the USGS ground-water monitoring networks during 2002-05. Water in the Snake River Plain aquifer primarily moves through fractures and interflow zones in basalt, generally flows southwestward, and eventually discharges at springs along the Snake River. The aquifer is recharged primarily from infiltration of irrigation water, infiltration of streamflow, ground-water inflow from adjoining mountain drainage basins, and infiltration of precipitation. From March-May 2001 to March-May 2005, water levels in wells declined throughout the INL area. The declines ranged from about 3 to 8 feet in the southwestern part of the INL, about 10 to 15 feet in the west central part of the INL, and about 6 to 11 feet in the northern part of the INL. Water levels in perched water wells declined also, with the water level dropping below the bottom of the pump in many wells during 2002-05. For radionuclides, concentrations that equal 3s, wheres s is the sample standard deviation, represent a measurement at the minimum detectable concentration, or 'reporting level'. Detectable concentrations of radiochemical constituents in water samples from wells in the Snake River Plain aquifer at the INL generally decreased or remained constant during 2002-05. Decreases in concentrations were attributed to decreased rates of radioactive-waste disposal

  18. Phosphorus dynamics and productivity in a sewage-impacted lowland chalk stream

    Science.gov (United States)

    Palmer-Felgate, Elizabeth J.; Jarvie, Helen P.; Williams, Richard J.; Mortimer, Robert J. G.; Loewenthal, Matthew; Neal, Colin

    2008-03-01

    SummaryHourly in situ phosphorus, conductivity, turbidity, dissolved oxygen, pH, and chlorophyll measurements were collected from January 2004 to November 2006 for the River Kennet, 2 km downstream of a sewage effluent inlet. Excess carbon dioxide pressure (EpCO 2) was calculated from continuous pH and spot alkalinity measurements. EpCO 2 and dissolved oxygen were used to estimate rates of photosynthesis and respiration. These parameters were examined alongside flow, water temperature and solar radiation to explore controls on phosphorus dynamics and in-stream productivity. Diurnal, event and seasonal patterns were observed in phosphorus concentrations. The diurnal and seasonal variations appeared to be related to the upstream sewage treatment works. The event patterns coincided with periods of high flow, and were attributed to diffuse sources. Chlorophyll behaved independently of phosphorus concentration and returned to baseline levels before photosynthesis rate. This indicated that, during the period of study, in-stream productivity was primarily controlled by aquatic plants other than phytoplankton.

  19. Savannah River National Laboratory Underground Counting Facility

    Science.gov (United States)

    Brown, Tim

    2006-10-01

    The SRNL UCF is capable of detecting extremely small amounts of radioactivity in samples, providing applications in forensics, environmental analyses, and nonproliferation. Past customers of the UCF have included NASA, (Long Duration Exposure Facility) the IAEA, (Iraq), and nonproliferation concerns. The SRNL UCF was designed to conduct ultra-low level gamma-ray analyses for radioisotopes at trace levels. Detection sensitivity is enhanced by background reduction, high detector efficiency, and long counting times. Backgrounds from cosmic-rays, construction materials, and radon are reduced by counting underground, active and passive shielding, (pre-WWII steel) and situation behind a Class 10,000 clean facility. High-detection efficiency is provided by a well detector for small samples and three large HPGe detectors. Sample concentration methods such as ashing or chemical separation are also used. Count times are measured in days. Recently, two SCUREF programs were completed with the University of South Carolina to further enhance UCF detection sensitivity. The first developed an ultra-low background HPGe detector and the second developed an anti-cosmic shield that further reduces the detector background. In this session, we will provide an overview status of the recent improvements made in the UCF and future directions for increasing sensitivity.

  20. Carbon isotopes and iodine concentrations in a Mississippi River delta core recording land use, sediment transport, and dam building in the river?s drainage basin

    OpenAIRE

    Santschi, Peter H.; Oktay, Sarah D.; Cifuentes, Luis

    2007-01-01

    Carbon isotopes and iodine concentrations in a Mississippi River delta core recording land use, sediment transport, and dam building in the river?s drainage basin correspondence: Corresponding author. (Santschi, Peter H.) (Santschi, Peter H.) Laboratory for Oceanographic and Environmental Research (LOER), Dept. of Marine Sciences and Oceanography, Texas A&M University at Galveston - 5007 Ave U--> , Galveston--> ...

  1. Comments on nuclear reactor safety in Ontario

    International Nuclear Information System (INIS)

    The Chalk River Technicians and Technologists Union representing 500 technical employees at the Chalk River Nuclear Laboratories of AECL submit comments on nuclear reactor safety to the Ontario Nuclear Safety Review. Issues identified by the Review Commissioner are addressed from the perspective of both a labour organization and experience in the nuclear R and D field. In general, Local 1568 believes Ontario's CANDU nuclear reactors are not only safe but also essential to the continued economic prosperity of the province

  2. Gran Sasso, laboratori fermi per inquinamento

    CERN Multimedia

    Arachi, Alessandra

    2003-01-01

    An experimental hall at the Gran Sasso laboratory has been closed by the Courts after a river was found contaminated. The institute decided to close all the installations in order to protect the health of citizens (1 page)

  3. Experimental meandering river with chute cutoffs

    NARCIS (Netherlands)

    Dijk, W.M. van; Lageweg, W.I. van de; Kleinhans, M.G.

    2012-01-01

    Braided rivers are relatively simple to produce in the laboratory, whereas dynamic meandering rivers have not been sustained beyond initial bend formation. Meandering is theoretically explained by bend instability growing from planimetric perturbation, which convects downstream. In this study, we ex

  4. Robotics at Savannah River

    International Nuclear Information System (INIS)

    A Robotics Technology Group was organized at the Savannah River Laboratory in August 1982. Many potential applications have been identified that will improve personnel safety, reduce operating costs, and increase productivity using modern robotics and automation. Several active projects are under way to procure robots, to develop unique techniques and systems for the site's processes, and to install the systems in the actual work environments. The projects and development programs are involved in the following general application areas: (1) glove boxes and shielded cell facilities, (2) laboratory chemical processes, (3) fabrication processes for reactor fuel assemblies, (4) sampling processes for separation areas, (5) emergency response in reactor areas, (6) fuel handling in reactor areas, and (7) remote radiation monitoring systems. A Robotics Development Laboratory has been set up for experimental and development work and for demonstration of robotic systems

  5. PowerPoint or chalk and talk: Perceptions of medical students versus dental students in a medical college in India

    Directory of Open Access Journals (Sweden)

    Vikas Seth

    2010-08-01

    Full Text Available Vikas Seth, Prerna Upadhyaya, Mushtaq Ahmad, Vijay MogheDepartment of Pharmacology, Mahatma Gandhi Medical College, Jaipur, Rajasthan, IndiaPurpose: To assess students’ perceptions of the impact of PowerPoint (PPT presentations in lectures in comparison to the traditional chalk and talk method and lectures using ­transparencies and overhead projector (TOHP. The study analyzes the preferences for teaching aids of medical students versus dental students.Methods: Second year medical and dental undergraduates were asked to fill in a nine-item questionnaire about their perceptions of the three lecture delivery methods. Following analysis of the questionnaire the students were interviewed further. The results were analyzed separately for medical and dental students to see if there was any difference in their perceptions.Results: The majority of the medical students (65.33% preferred PPT presentations, while 15.16% of students preferred the lectures using chalkboard, and 19.51% preferred TOHP for teaching (P < 0.001. Of the dental students: 41.84% preferred chalkboard, 31.21% preferred TOHP, and 25.85% students preferred PPT presentations in the lectures (P < 0.05. Some important comments of the students were also recorded on interview which could be valuable for the medical teachers.Conclusion: The medical students clearly preferred the use of PPT presentations while the dental students did not. The study does not bring out evidence based superiority of any lecture delivery method. It appears that in the hands of a trained teacher any teaching aid would be appropriate and effective. This highlights the need for formal training in teaching technologies to develop good presentation skills and thus motivate the students.Keywords: audiovisual aids, medical education, lecture delivery methods, PowerPoint presentations, OHP, chalkboard

  6. The impact of broadleaved woodland on water resources in lowland UK: I. Soil water changes below beech woodland and grass on chalk sites in Hampshire

    Directory of Open Access Journals (Sweden)

    J. Roberts

    2005-01-01

    Full Text Available The possible effects of broadleaved woodland on recharge to the UK Chalk aquifer have led to a study of evaporation and transpiration from beech woodland (Black Wood and pasture (Bridgets Farm, growing in shallow soils above chalk in Hampshire. Eddy correlation measurements of energy balance components above both the forest and the grassland enabled calculation of latent heat flux (evaporation and transpiration as a residual. Comparative measurements of soil water content and soil water potential in 9 m profiles under both forest and grassland found changes in soil water content down to 6 m at both sites; however, the soil water potential measurements showed upward movement of water only above a depth of about 2 m. Below this depth, water continued to drain and the soil water potential measurements showed downward movement of water at both sites, notwithstanding significant negative soil water potentials in the chalk and soil above. Seasonal differences occur in the soil water content profiles under broadleaved woodland and grass. Before the woodland foliage emerges, greater drying beneath the grassland is offset in late spring and early summer by increased drying under the forest. Yet, when the change in soil water profiles is at a maximum, in late summer, the profiles below woodland and grass are very similar. A comparison of soil water balances for Black Wood and Bridgets Farm using changes in soil water contents, local rainfall and evaporation measured by the energy balance approach allowed drainage to be calculated at each site. Although seasonal differences occurred, the difference in cumulative drainage below broadleaved woodland and grass was small.

  7. Analytical Laboratories

    Data.gov (United States)

    Federal Laboratory Consortium — NETL’s analytical laboratories in Pittsburgh, PA, and Albany, OR, give researchers access to the equipment they need to thoroughly study the properties of materials...

  8. National laboratories

    International Nuclear Information System (INIS)

    The foundation of a 'National Laboratory' which would support a Research center in synchrotron radiation applications is proposed. The essential features of such a laboratory differing of others centers in Brazil are presented. (L.C.)

  9. Laboratory Tests

    Science.gov (United States)

    Laboratory tests check a sample of your blood, urine, or body tissues. A technician or your doctor ... compare your results to results from previous tests. Laboratory tests are often part of a routine checkup ...

  10. Computational Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — This laboratory contains a number of commercial off-the-shelf and in-house software packages allowing for both statistical analysis as well as mathematical modeling...

  11. On Rivers

    OpenAIRE

    Gleason, Colin Joseph

    2016-01-01

    Despite the importance of rivers to industry, agriculture, the climate system, and global ecosystems, our current knowledge of river discharge (volume of available water per unit time) is surprisingly poor for many regions of the world as political cloistering, aging infrastructure, and rapid human changes limit our ability to understand global surface waters holistically. Closing this knowledge gap is critical for better management of surface water in light of drought and increasing human de...

  12. Meandering rivers - feedbacks between channel dynamics, floodplain and vegetation

    OpenAIRE

    Dijk, W.M. van

    2013-01-01

    Rivers have distinctive channel patterns such as multi-channel braiding and single-channel meandering. Why these different river patterns emerge is only qualitatively understood. Yet, we have not been able to retain dynamic meandering in laboratory experiments. The main objective of this thesis was to develop experimental settings in the laboratory that lead to dynamic meandering, in order to determine how rivers self-organize their morphology through interactions between channels, floodplain...

  13. Area balance and strain in an extensional fault system: Strategies for improved oil recovery in fractured chalk, Gilbertown Field, southwestern Alabama. Annual report, March 1996--March 1997

    Energy Technology Data Exchange (ETDEWEB)

    Pashin, J.C.; Raymond, D.E.; Rindsberg, A.K.; Alabi, G.G.; Groshong, R.H.

    1997-08-01

    Gilbertown Field is the oldest oil field in Alabama and produces oil from chalk of the Upper Cretaceous Selma Group and from sandstone of the Eutaw Formation along the southern margin of the Gilbertown fault system. Most of the field has been in primary recovery since establishment, but production has declined to marginally economic levels. This investigation applies advanced geologic concepts designed to aid implementation of improved recovery programs. The Gilbertown fault system is detached at the base of Jurassic salt. The fault system began forming as a half graben and evolved in to a full graben by the Late Cretaceous. Conventional trapping mechanisms are effective in Eutaw sandstone, whereas oil in Selma chalk is trapped in faults and fault-related fractures. Burial modeling establishes that the subsidence history of the Gilbertown area is typical of extensional basins and includes a major component of sediment loading and compaction. Surface mapping and fracture analysis indicate that faults offset strata as young as Miocene and that joints may be related to regional uplift postdating fault movement. Preliminary balanced structural models of the Gilbertown fault system indicate that synsedimentary growth factors need to be incorporated into the basic equations of area balance to model strain and predict fractures in Selma and Eutaw reservoirs.

  14. Skjern River Restoration Counterfactual

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2014-01-01

    In 2003 the Skjern River Restoration Project in Denmark was awarded the prestigious Europa Nostra Prize for ‘conserving the European cultural heritage’ (Danish Nature Agency 2005). In this case, however, it seems that the conservation of one cultural heritage came at the expense of another cultural...... the 1960s is perceived as a catalyst for the development of nature. As such the idea of the palimpsest might bring a valuable openness into the field of nature restoration rendering sites of nature restoration less like museums and more like laboratories. References: Clemmensen, T. J. (2014), ‘The...

  15. Laboratory Building.

    Energy Technology Data Exchange (ETDEWEB)

    Herrera, Joshua M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-03-01

    This report is an analysis of the means of egress and life safety requirements for the laboratory building. The building is located at Sandia National Laboratories (SNL) in Albuquerque, NM. The report includes a prescriptive-based analysis as well as a performance-based analysis. Following the analysis are appendices which contain maps of the laboratory building used throughout the analysis. The top of all the maps is assumed to be north.

  16. Visualization Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Evaluates and improves the operational effectiveness of existing and emerging electronic warfare systems. By analyzing and visualizing simulation results...

  17. Dynamics Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Dynamics Lab replicates vibration environments for every Navy platform. Testing performed includes: Flight Clearance, Component Improvement, Qualification, Life...

  18. Chemistry Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Purpose: To conduct fundamental studies of highway materials aimed at understanding both failure mechanisms and superior performance. New standard test methods are...

  19. Uranium series geochemistry in aquifers: quantification of transport mechanisms of uranium and daughter products: the chalk aquifer (Champagne, France); Desequilibres des series de l'uranium dans les aquiferes: quantification des mecanismes de transport de l'uranium et de ses descendants: cas de l'aquifere de la craie (Champagne, France)

    Energy Technology Data Exchange (ETDEWEB)

    Hubert, A

    2005-09-15

    With the increase of contaminant flux of radionuclides in surface environment (soil, river, aquifer...), there is a need to understand and model the processes that control the distribution of uranium and its daughter products during transport within aquifers. We have used U-series disequilibria as an analogue for the transport of uranium and its daughter products in aquifer to understand such mechanisms. The measurements of uranium ({sup 234}U et {sup 238}U), thorium ({sup 230}Th et {sup 232}Th), {sup 226}Ra and {sup 222}Rn isotopes in the solid and liquid phases of the chalk aquifer in Champagne (East of France) allows us to understand the processes responsible for fractionation within the uranium decay chain. Fractionations are induced by physical and chemical properties of the elements (leaching, adsorption) but also by radioactive properties (recoil effect during {alpha}-decay). For the first time a comprehensive sampling of the solid phase has been performed, allowing quantifying mechanisms responsible for the long term evolution of the aquifer. A non steady state 1D model has been developed which takes into account leaching, adsorption processes as well as radioactive filiation and {alpha}-recoil effect. Retardation coefficients have been calculated for uranium, thorium and radium. The aquifer is characterised by a double porosity, and the contribution of fracture and matrix porosity on the water/rock interaction processes has been estimated. (author)

  20. Deep waters : the Ottawa River and Canada's nuclear adventure

    International Nuclear Information System (INIS)

    Deep Waters is an intimate account of the principal events and personalities involved in the successful development of the Canadian nuclear power system (CANDU), an achievement that is arguably one of Canada's greatest scientific and technical successes of the twentieth century. The author tells the stories of the people involved and the problems they faced and overcame and also relates the history of the development of the town of Deep River, built exclusively for the scientists and employees of the Chalk River Project and describes the impact of the Project on the traditional communities of the Ottawa Valley. Public understanding of nuclear power has remained confused, yet decisions about whether and how to use it are of vital importance to Canadians today - and will increase in importance as we seek to maintain our standard of living without doing irreparable damage to the environment around us. Deep Waters examines the issues involved in the use of nuclear power without over-emphasizing its positive aspects or avoiding its negative aspects.

  1. Implementation of agronomical and geochemical modules into a 3D groundwater code for assessing nitrate storage and transport through unconfined Chalk aquifer

    Science.gov (United States)

    Picot-Colbeaux, Géraldine; Devau, Nicolas; Thiéry, Dominique; Pettenati, Marie; Surdyk, Nicolas; Parmentier, Marc; Amraoui, Nadia; Crastes de Paulet, François; André, Laurent

    2016-04-01

    Chalk aquifer is the main water resource for domestic water supply in many parts in northern France. In same basin, groundwater is frequently affected by quality problems concerning nitrates. Often close to or above the drinking water standards, nitrate concentration in groundwater is mainly due to historical agriculture practices, combined with leakage and aquifer recharge through the vadose zone. The complexity of processes occurring into such an environment leads to take into account a lot of knowledge on agronomy, geochemistry and hydrogeology in order to understand, model and predict the spatiotemporal evolution of nitrate content and provide a decision support tool for the water producers and stakeholders. To succeed in this challenge, conceptual and numerical models representing accurately the Chalk aquifer specificity need to be developed. A multidisciplinary approach is developed to simulate storage and transport from the ground surface until groundwater. This involves a new agronomic module "NITRATE" (NItrogen TRansfer for Arable soil to groundwaTEr), a soil-crop model allowing to calculate nitrogen mass balance in arable soil, and the "PHREEQC" numerical code for geochemical calculations, both coupled with the 3D transient groundwater numerical code "MARTHE". Otherwise, new development achieved on MARTHE code allows the use of dual porosity and permeability calculations needed in the fissured Chalk aquifer context. This method concerning the integration of existing multi-disciplinary tools is a real challenge to reduce the number of parameters by selecting the relevant equations and simplifying the equations without altering the signal. The robustness and the validity of these numerical developments are tested step by step with several simulations constrained by climate forcing, land use and nitrogen inputs over several decades. In the first time, simulations are performed in a 1D vertical unsaturated soil column for representing experimental nitrates

  2. Chalk and computers

    DEFF Research Database (Denmark)

    Rasmussen, Lisa Rosén

    Since 1970 school books have first been supplemented by photocopies and later PDF files and the use of Internet sites. Chalkboards have been replaced by Smart Boards and notebooks by laptops and IPADS. Digital media has made its way into the classroom and into everyday school life. This has been...... highly connected to technological innovation that across the period has inspired hope as well as fear in teachers, pupils and parents. I take my starting point in the changing teaching aids of everyday school life to analyse how the technological development has been dealt with in the Danish school in...... the period 1970-2011. I wish to discuss how the analysis can benefit from a focus on the parallel introduction of thoughts concerning children’s culture, the competent child and the linkage of ‘Play & learn’. Looking at everyday life I also aim at discussing how the introduction of the new teaching...

  3. An update of hydrologic conditions and distribution of selected constituents in water, eastern Snake River Plain aquifer and perched groundwater zones, Idaho National Laboratory, Idaho, emphasis 2009–11

    Science.gov (United States)

    Davis, Linda C.; Bartholomay, Roy C.; Rattray, Gordon W.

    2013-01-01

    Since 1952, wastewater discharged to infiltration ponds (also called percolation ponds) and disposal wells at the Idaho National Laboratory (INL) has affected water quality in the eastern Snake River Plain (ESRP) aquifer and perched groundwater zones underlying the INL. The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy, maintains groundwater monitoring networks at the INL to determine hydrologic trends, and to delineate the movement of radiochemical and chemical wastes in the aquifer and in perched groundwater zones. This report presents an analysis of water-level and water-quality data collected from aquifer, multilevel monitoring system (MLMS), and perched groundwater wells in the USGS groundwater monitoring networks during 2009–11. Water in the ESRP aquifer primarily moves through fractures and interflow zones in basalt, generally flows southwestward, and eventually discharges at springs along the Snake River. The aquifer primarily is recharged from infiltration of irrigation water, infiltration of streamflow, groundwater inflow from adjoining mountain drainage basins, and infiltration of precipitation. From March–May 2009 to March–May 2011, water levels in wells generally declined in the northern part of the INL. Water levels generally rose in the central and eastern parts of the INL. Detectable concentrations of radiochemical constituents in water samples from aquifer wells or MLMS equipped wells in the ESRP aquifer at the INL generally decreased or remained constant during 2009–11. Decreases in concentrations were attributed to radioactive decay, changes in waste-disposal methods, and dilution from recharge and underflow. In 2011, concentrations of tritium in groundwater from 50 of 127 aquifer wells were greater than or equal to the reporting level and ranged from 200±60 to 7,000±260 picocuries per liter. Tritium concentrations from one or more discrete zones from four wells equipped with MLMS were greater than or

  4. Laboratory Tests

    Science.gov (United States)

    ... Medical Devices Radiation-Emitting Products Vaccines, Blood & Biologics Animal & ... or conditions. What are lab tests? Laboratory tests are medical procedures that involve testing samples of blood, urine, or other tissues or ...

  5. Grays River Watershed Geomorphic Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Geist, David R

    2005-04-30

    This investigation, completed for the Pacific Northwest National Laboratory (PNNL), is part of the Grays River Watershed and Biological Assessment commissioned by Bonneville Power Administration under project number 2003-013-00 to assess impacts on salmon habitat in the upper Grays River watershed and present recommendations for habitat improvement. This report presents the findings of the geomorphic assessment and is intended to support the overall PNNL project by evaluating the following: The effects of historical and current land use practices on erosion and sedimentation within the channel network The ways in which these effects have influenced the sediment budget of the upper watershed The resulting responses in the main stem Grays River upstream of State Highway 4 The past and future implications for salmon habitat.

  6. Savannah River Plant Works Technical Department progress report, July 1960: Deleted Version

    Energy Technology Data Exchange (ETDEWEB)

    1960-08-17

    This progress report by the Atomic Energy Division of the Savannah River Plant covers: Reactor Technology; Separation Technology; Engineering Assistance; Health Physics; and General Laboratory work. (JT)

  7. Savannah River Plant Works Technical Department monthly progress report for May 1958: Deleted Version

    Energy Technology Data Exchange (ETDEWEB)

    1958-06-17

    This progress report by the Atomic Energy Division of the Savannah River Plant covers: Reactor Technology; Separation Technology; Engineering Assistance; Health Physics; and General Laboratory Work. (JT)

  8. YELLOWSTONE RIVER WATCH (YRW)

    Science.gov (United States)

    Yellowstone River Watch seeks to expand its monitoring and education efforts throughout the Yellowstone River Basin by actively recruiting and training new teacher members. Yellowstone River Watch also seeks to advance existing school programs by offering quality assurance/quali...

  9. Multi-model comparison of a major flood in the groundwater-fed basin of the Somme River (France

    Directory of Open Access Journals (Sweden)

    F. Habets

    2009-09-01

    Full Text Available The Somme River Basin is located above a chalk aquifer and the discharge of the somme River is highly influenced by groundwater inflow (90% of river discharge is baseflow. In 2001, the Somme River Basin suffered from a major flood causing damages estimated to 100 million Euro (Deneux and Martin, 2001. The purpose of the present research is to evaluate the ability of four hydrologic models to reproduce flood events in the Somme River Basin over an 18-year period, by comparison with observed river discharge and piezometric head as well as satellite-derived extents of the flooded area. The models used differ in their computation of the surface water budget and in their representation of saturated and unsaturated zones. One model needed structural modification to be able to accurately simulate the riverflows of the Somme river. The models obtained fair to good simulations of the observed piezometric heads, but they all overestimate the piezometric level after flooding, possibly because of a simplistic representation of the deep unsaturated flow. Models differ in their annual partition of the infiltration of water within the root zone (mostly driven by simulated evapotranspiration, but these differences are attenuated by water transfers within the saturated and unsaturated zone. As a consequence, the inter-model dispersion of the computed annual baseflow is reduced. The aquifer overflow areas simulated during flooding compare well with local data and satellite images. The models showed that this overflow occurs almost every year in the same areas (in the floodplain, and that the flooding of 2001 was characterized by an increase in the quantity of the overflow and not much by a spreading of the overflow areas. Inconsistencies between river discharge and piezometric levels suggest that further investigation are needed to estimate the relative influence of unsaturated and saturated zones on the hydrodynamics of the Somme River Basin.

  10. Multi-model comparison of a major flood in the groundwater-fed basin of the Somme River (France

    Directory of Open Access Journals (Sweden)

    F. Habets

    2010-01-01

    Full Text Available The Somme River Basin is located above a chalk aquifer and the discharge of the somme River is highly influenced by groundwater inflow (90% of river discharge is baseflow. In 2001, the Somme River Basin suffered from a major flood causing damages estimated to 100 million euro (Deneux and Martin, 2001. The purpose of the present research is to evaluate the ability of four hydrologic models to reproduce flood events in the Somme River Basin over an 18-year period, by comparison with observed river discharge and piezometric level as well as satellite-derived extents of flooded area. The models used differ in their computation of surface water budget and in their representation of saturated and unsaturated zones. One model needed structural modification to be able to accurately simulate the riverflows of the Somme river. The models obtained fair to good simulations of the observed piezometric levels, but they all overestimate the piezometric level after flooding, possibly because of a simplistic representation of deep unsaturated flow. Models differ in their annual partition of the infiltration of water within the root zone (mostly driven by simulated evapotranspiration, but these differences are attenuated by water transfers within the saturated and unsaturated zone. As a consequence, the inter-model dispersion of the computed annual baseflow is reduced. The aquifer overflow areas simulated during flooding compare well with local data and satellite images. The models showed that this overflow occurs almost every year in the same areas (in floodplain, and that the flooding of 2001 was characterized by an increase in the quantity of the overflow and not much by a spreading of the overflow areas. Inconsistencies between river discharge and piezometric levels suggest that further investigation are needed to estimate the relative influence of unsaturated and saturated zones on the hydrodynamics of the Somme River Basin.

  11. Saxton Transportation Operations Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Saxton Transportation Operations Laboratory (Saxton Laboratory) is a state-of-the-art facility for conducting transportation operations research. The laboratory...

  12. River Surface Velocity Fields Observed From Space

    Science.gov (United States)

    Kääb, A.; Prowse, T. D.

    2011-12-01

    Knowledge of water-surface velocities in rivers is useful for understanding a wide range of lotic processes and systems, such as water and ice fluxes and forces, mixing, solute and sediment transport, bed and bank stability, aquatic and riparian ecology, and extreme hydrologic events. In cold regions, river-ice break up and the associated downstream transport of ice debris is often the most important hydrological event of the year, producing flood levels that commonly exceed those for the open-water period and dramatic consequences for river infrastructure and ecology. Quantification of river surface velocity and currents has relied mostly on very scarce in situ measurements or particle tracking in laboratory models, with few attempts to cover entire river reaches. Accurate and complete surface-velocity fields on rivers have rarely been produced. In this study, we use river-ice debris as an index of surface water velocity, and track it over a time period of about one minute, which is the typical time lapse between the two or more images that form a stereo data set in spaceborne, along-track optical-stereo mapping. Using this novel approach, we measure and visualize for the first time the almost complete two-dimensional surface velocity fields over many tens of kilometers long river reaches. We present the types of short time-delay imagery suitable for the measurements and discuss application examples on a number of North-American (e.g. Figs. 1 and 2) and Siberian rivers, using a range of high and medium resolution imagery. The methodology and results of the novel approach will be valuable to a number of disciplines requiring detailed information about river flow, such as hydraulics, hydrology, river ecology and natural-hazard management.

  13. Virtual Laboratories

    CERN Document Server

    Hut, P

    2006-01-01

    At the frontier of most areas in science, computer simulations play a central role. The traditional division of natural science into experimental and theoretical investigations is now completely outdated. Instead, theory, simulation, and experimentation form three equally essential aspects, each with its own unique flavor and challenges. Yet, education in computational science is still lagging far behind, and the number of text books in this area is minuscule compared to the many text books on theoretical and experimental science. As a result, many researchers still carry out simulations in a haphazard way, without properly setting up the computational equivalent of a well equipped laboratory. The art of creating such a virtual laboratory, while providing proper extensibility and documentation, is still in its infancy. A new approach is described here, Open Knowledge, as an extension of the notion of Open Source software. Besides open source code, manuals, and primers, an open knowledge project provides simul...

  14. Meandering rivers - feedbacks between channel dynamics, floodplain and vegetation

    NARCIS (Netherlands)

    van Dijk, W.M.

    2013-01-01

    Rivers have distinctive channel patterns such as multi-channel braiding and single-channel meandering. Why these different river patterns emerge is only qualitatively understood. Yet, we have not been able to retain dynamic meandering in laboratory experiments. The main objective of this thesis was

  15. Laboratory investigations

    International Nuclear Information System (INIS)

    Our task is to design mined-repository systems that will adequately secure high-level nuclear waste for at least 10,000 yr and that will be mechanically stable for 50 to 100-yr periods of retrievability during which mistakes could be corrected and a valuable source of energy could be reclaimed, should national policy on the reprocessing of spent fuel ever change. The only credible path for the escape of radionuclides from the repository to the biosphere is through ground-water, and in hard rock, bulk permeability is largely governed by natural and artificial fracture systems. Catastrophic failure of an excavation in hard rock is likely to occur at the weakest links - the discontinuities in the rock mass that is perturbed first by mining and then by radiogenic heating. The laboratory can contribute precise measurements of the pertinent thermomechanical, hydrological and chemical properties and improve our understanding of the fundamental processes through careful experiments under well controlled conditions that simulate the prototype environment. Thus laboratory investigations are necessary, but they are not sufficient, for conventional sample sizes are small relative to natural defects like joints - i.e., the rock mass is not a continuum - and test durations are short compared to those that predictive modeling must take into account. Laboratory investigators can contribute substantially more useful data if they are provided facilities for testing large specimens(say one cubic meter) and for creep testing of all candidate host rocks. Even so, extrapolations of laboratory data to the field in neither space nor time are valid without the firm theoretical foundations yet to be built. Meanwhile in-situ measurements of structure-sensitive physical properties and access to direct observations of rock-mass character will be absolutely necessary

  16. Culham Laboratory

    International Nuclear Information System (INIS)

    The report contains summaries of work carried out under the following headings: fusion research experiments; U.K. contribution to the JET project; supporting studies; theoretical plasma physics, computational physics and computing; fusion reactor studies; engineering and technology; contract research; external relations; staff, finance and services. Appendices cover main characteristics of Culham fusion experiments, staff, extra-mural projects supported by Culham Laboratory, and a list of papers written by Culham staff. (U.K.)

  17. Apprentices train for nuclear maintenance

    International Nuclear Information System (INIS)

    A combination of in-plant training, the Ontario provincial apprenticeship training program, and supplementary home study training programs are being combined in an extensive training program for apprentices at Chalk River Nuclear Laboratories. The unusual scope of the laboratory's work and the challenging jobs are valuable in preparing the apprentice for work in nuclear industry. (R.A.)

  18. River Morphology and River Channel Changes

    Institute of Scientific and Technical Information of China (English)

    CHANG Howard H

    2008-01-01

    River morphology has been a subject of great challenge to scientists and engineers who recognize that any effort with regard to river engineering must be based on a proper understanding of the morphological features involved and the responses to the imposed changes. In this paper,an overview of river morphology is presented from the geomorphic viewpoint. Included in the scope are the regime concept, river channel classification, thresholds in river morphology, and geomor-phic analysis of river responses. Analytical approach to river morphology based on the physical principles for the hydraulics of flow and sediment transport processes is also presented. The appli-cation of analytical river morphology is demonstrated by an example. Modeling is the modern tech-nique to determine both short-term and long-term river channel responses to any change in the en-vironment. The physical foundation of fluvial process-response must be applied in formatting a mathematical model. A brief introduction of the mathematical model FLUVIAL-12 is described.

  19. Savannah River Site dose control

    International Nuclear Information System (INIS)

    Health physicists from the Brookhaven National Laboratory (BNL) visited the Savannah River Site (SRS) as one of 12 facilities operated by the Department of Energy (DOE) contractors with annual collective dose equivalents greater than 100 person-rem (100 person-cSv). Their charter was to review, evaluate and summarize as low as reasonably achievable (ALARA) techniques, methods and practices as implemented. This presentation gives an overview of the two selected ALARA practices implemented at the SRS: Administrative Exposure Limits and Goal Setting. These dose control methods are used to assure that individual and collective occupational doses are ALARA and within regulatory limits

  20. Distributed Energy Technology Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Distributed Energy Technologies Laboratory (DETL) is an extension of the power electronics testing capabilities of the Photovoltaic System Evaluation Laboratory...

  1. FOOTWEAR PERFORMANCE LABORATORY

    Data.gov (United States)

    Federal Laboratory Consortium — This laboratory provides biomechanical and physical analyses for both military and commercial footwear. The laboratory contains equipment that is integral to the us...

  2. Bio Engineering Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Description/History: Chemistry and biology laboratories The Bio Engineering Laboratory (BeL) is theonly full spectrum biotechnology capability within the Department...

  3. Physical Sciences Laboratory (PSL)

    Data.gov (United States)

    Federal Laboratory Consortium — PNNL's Physical Sciences Laboratory (PSL) houses 22 research laboratories for conducting a wide-range of research including catalyst formulation, chemical analysis,...

  4. The CHPRC Columbia River Protection Project Quality Assurance Project Plan

    Energy Technology Data Exchange (ETDEWEB)

    Fix, N. J.

    2008-11-30

    Pacific Northwest National Laboratory researchers are working on the CHPRC Columbia River Protection Project (hereafter referred to as the Columbia River Project). This is a follow-on project, funded by CH2M Hill Plateau Remediation Company, LLC (CHPRC), to the Fluor Hanford, Inc. Columbia River Protection Project. The work scope consists of a number of CHPRC funded, related projects that are managed under a master project (project number 55109). All contract releases associated with the Fluor Hanford Columbia River Project (Fluor Hanford, Inc. Contract 27647) and the CHPRC Columbia River Project (Contract 36402) will be collected under this master project. Each project within the master project is authorized by a CHPRC contract release that contains the project-specific statement of work. This Quality Assurance Project Plan provides the quality assurance requirements and processes that will be followed by the Columbia River Project staff.

  5. Onchocerciasis (River Blindness) FAQs

    Science.gov (United States)

    ... The CDC Parasites - Onchocerciasis (also known as River Blindness) Note: Javascript is disabled or is not supported ... infected Simulium blackfly. It is also called River Blindness because the fly that transmits infection breeds in ...

  6. Allegheny County Major Rivers

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset contains locations of major rivers that flow through Allegheny County. These shapes have been taken from the Hydrology dataset. The Ohio River,...

  7. Iowa's Sovereign Meandered Rivers

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This data set depicts Iowa's Meandered Rivers. These rivers are deemed sovereign land & therefore require any person wishing to conduct construction activities...

  8. Qingjiang River Developer

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    THE 400-kilometer Qingjiang River, second tributary of the Yangtze River in Hubei Province, has a drainage area of 17,000 square kilometers. Its advantageous natural conditions have made it a key water power development project.

  9. River and Stream Pollution

    Science.gov (United States)

    ... Topics Games Activities Lessons MENU River and Stream Pollution Kids Homepage Topics Pollution River and Stream Pollution ... stream in the first place by disturbing the land as little as possible. Farmers and construction workers ...

  10. Mithi River Restoration Project

    OpenAIRE

    Sanghani, Himanshu

    2009-01-01

    It took only few years to turn a naturally owing river into a drain. 17.84 k.m stretch of MithiNadi (river), an arterial river, running along north-south axis of Bombay (Mumbai) is facing the grimproblems of backyard atrocities. Finding its way through the odds of household garbage, industrialsewage, other pollutants and encroachments, Mithi river originates from the conuence of two essentialreservoirs; Vihar Lake and Powai Lake and merging with Arabian Sea at Mahim creek. The stategovernment...

  11. LABORATORY INVESTIGATIONS OF SILICATE MUD CONTAMINATION WITH CALCIUM

    OpenAIRE

    Nediljka Gaurina-Međimurec; Katarina Simon; Davorin Matanović

    2004-01-01

    The silicate-based drilling fluid is a low solids KCl/polymer system with the addition of soluble sodium or potassium silicate to enhance inhibition and wellbore stability. Silicate-based drilling fluids exhibit remarkable shale and chalk stabilizing properties, resulting in gauge hole and the formation of firm cuttings when drilling reactive shales and soft chalks. Silicates protect shales by in-situ gellation when exposed to the neutral pore fluid and precipitation, which occurs on contact ...

  12. Transport of plutonium by the Mississippi River system and other rivers in the southern United States

    International Nuclear Information System (INIS)

    The distribution of fallout Pu has been studied in the sediments and water of the Mississippi River and eight other rivers. Plutonium content of the sediments is related to grain size and Fe and Mn content. Rivers in human climates show relatively high organic carbon (3 to 4%) and high /sup 239,240)Pu content (36 to 131 dpm/kg) in their suspended sediments. Dissolved Pu is very low in all the rivers; distribution coefficients vary from 104 to 105. The 238Pu//sup 239,240/Pu ratios are low in all the river sediments (∼.06) except the Miami River in Ohio, where ratios as high as 99 were measured. The high ratios originate from the Mound Laboratory Pu processing plant at Miamisburg, Ohio, and can be traced downstream to the junction with the Ohio River. Mississippi River suspended sediment shows a continual decrease of /sup 239,240/Pu content over a 7 year time period. An exponential curve best-fit through the data predicts a half time of decrease equal to 4.3 years. The decrease in Pu content of river sediment results from several factors: cessation of atmospheric weapons testing; transport of Pu to deeper levels of soil profiles; storage of sediment in flood plains and behind dams; and dilution by erosion by older, prebomb soil material. The amount of fallout Pu now removed from the Mississippi River drainage basin to the ocean is 11% as a maximum estimate. Most the fallout Pu in the Mississippi drainage basin will remain on the continent unless there are major changes in erosion and sediment transport patterns in the basin itself. 56 references, 7 figures, 2 tables

  13. Raft River geoscience case study

    Energy Technology Data Exchange (ETDEWEB)

    Dolenc, M.R.; Hull, L.C.; Mizell, S.A.; Russell, B.F.; Skiba, P.A.; Strawn, J.A.; Tullis, J.A.

    1981-11-01

    The Raft River Geothermal Site has been evaluated over the past eight years by the United States Geological Survey and the Idaho National Engineering Laboratory as a moderate-temperature geothermal resource. The geoscience data gathered in the drilling and testing of seven geothermal wells suggest that the Raft River thermal reservoir is: (a) produced from fractures found at the contact metamorphic zone, apparently the base of detached normal faulting from the Bridge and Horse Well Fault zones of the Jim Sage Mountains; (b) anisotropic, with the major axis of hydraulic conductivity coincident to the Bridge Fault Zone; (c) hydraulically connected to the shallow thermal fluid of the Crook and BLM wells based upon both geochemistry and pressure response; (d) controlled by a mixture of diluted meteoric water recharging from the northwest and a saline sodium chloride water entering from the southwest. Although the hydrogeologic environment of the Raft River geothermal area is very complex and unique, it is typical of many Basin and Range systems.

  14. Sharp bends associated with deep scours in a tropical river: The river Mahakam (East Kalimantan, Indonesia)

    NARCIS (Netherlands)

    Vermeulen, B.; Hoitink, A.J.F.; Berkum, van S.W.; Hidayat, H.

    2014-01-01

    Autogenic scouring in sharp river bends has received ample attention in laboratory and modeling studies. These studies have significantly advanced our understanding of how flow processes are influenced by strong curvature and how they affect the bathymetry. Here we present a 300 km reach of the Maha

  15. Impedance imaging in core analysis. Imaging of phase distributions in samples of natural cores of North Sea chalk containing conducting as well as non-conducting fluids. Part: 1-3

    Energy Technology Data Exchange (ETDEWEB)

    Laursen, S. [DTU, Inst. for Kemi (Denmark)] Moeller Nielsen, C. [DTU, Inst. for Energiteknik (Denmark)

    1997-12-31

    The present report documents the efforts to develop an impedance method for determining the distribution of the water saturation in a chalk core sample. Measurement of this distribution during a displacement process will make it possible to make numerical simulations of the process which may in turn reveal important rock parameters. The impedance method is one among other methods to determine saturation profiles in a research programme on rock parameters with participants from Danmarks Tekniske Universitet, DTU, and Danmarks og Groenlands Geologiske Undersoegelse, GEUS. The other methods investigated are nmr-scanning and {gamma}-logging. (au)

  16. Dosimetric Implications of Atmospheric Dispersal of Tritium Near a Heavy-water Research Reactor Facility

    International Nuclear Information System (INIS)

    An estimate of the tritium dose to the public in the vicinity of the heavy water research reactor facility at AECL-Chalk River Laboratories, Ontario, Canada, has largely been accomplished from analyses on regularly-collected samples of air, precipitation, drinking water and foodstuffs (pasture, fruit, vegetables and milk) and environmental dose models. To increase the confidence with which public doses are calculated, tritium doses were estimated directly from the ratio of tritiated species in urine samples from members of the general public. Single cumulative 24 h urine samples from a few adults living in the vicinity of the heavy-water research reactor facility at Chalk River Laboratories, Canada were collected and analysed for tritiated water and organically bound tritium. The participants were from Ottawa (200 km east), Deep River (10 km west) and Chalk River Laboratories. Tritiated water concentrations in urine ranged from 6.5 Bq.l-1 for the Ottawa resident to 15.9 Bq.l-1 for the Deep River resident, and were comparable to the ambient levels of tritium-in-precipitation at their locations. The ultra-low levels of organically bound tritium in urine from these same individuals were measured by 3He-ingrowth mass spectrometry and were 0.06 Bq.l-1 (Ottawa) and 0.29 Bq.l-1 (Deep River). For Chalk River Laboratories workers, tritiated water concentrations in urine ranged from 32 Bq.l-1 to 9.2x104 Bq.l-1, depending on the ambient levels of tritium in their workplace. The organically bound tritium concentrations in urine from the same workers were between 0.08 Bq.l-1 and 350 Bq.l-1. With a model based on the ratio of tritiated water to organically bound tritium in urine, the estimated dose arising from organically bound tritium in the body for the Ottawa and Deep River residents was about 26% and 50%, respectively, of the body water tritium dose. The workers in a reactor building at Chalk River Laboratories has less than 10% dose contribution from organically bound

  17. 76 FR 51887 - Safety Zone; Patuxent River, Patuxent River, MD

    Science.gov (United States)

    2011-08-19

    ...) entitled ``Safety Zone; Patuxent River, Patuxent River, MD'' in the Federal Register (76 FR 36447). We... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Patuxent River, Patuxent River, MD AGENCY... safety zone during the ``NAS Patuxent River Air Expo '11,'' which consists of aerial...

  18. PROGRESS IN STUDIES ON ICE ACCUMULATION IN RIVER BENDS

    Institute of Scientific and Technical Information of China (English)

    WANG Jun; CHEN Pang-pang; SUI Jue-yi

    2011-01-01

    River ice is an important hydraulic element in temperate and polar environments and would affect hydrodynamic conditions of rivers through changes both in the boundary conditions and the thermal regime.The river bend has been reported as the common location for the initiation of ice jams because the water flow along a river bend is markedly affected by the channel curvature.In this article,the experimental studies about the ice accumulation in a river bend are reviewed.Based on experiments conducted so far,the criteria for the formation of ice jams in the river bend,the mechanisms of the ice accumulation in the river bend and the thickness profile of the ice accumulation in the river bend are discussed.The k- ε two-equation turbulence model is used to simulate the ice accumulation under an ice cover along a river bend.A formula is proposed for describing the deformation of the ice jam bottom.Our results indicate that all simulated thickness of the ice accumulation agrees reasonably well with the measured thickness of the ice accumulation in the laboratory.

  19. AFSC/NMML/CCEP: Diet of Pacific harbor seals at Umpqua River, Oregon and Columbia River, Oregon/Washington during 1994 through 2005

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — From 1994 to 2005, The National Marine Mammal Laboratories' California Current Ecosystem Program (AFSC/NOAA) collected fecal samples at the Umpqua River, Oregon and...

  20. Experimental Study of Discharge Characteristics in a Compound Meandering River

    OpenAIRE

    Md. Abdullah Al Amin

    2013-01-01

    Most of the river flow in the world can be characterized as compound meandering channel in which the discharge distributions are very intricate. Now-a-days engineers, planners as well as researchers are highly interested in predicting precisely and reliably the quantitative estimates of discharge in a compound meandering river. A Laboratory experiment has been performed in a compound meandering channel with symmetric cross-sections having floodplain width ratio of 1, 1.67, 2.33, 3 and depth r...

  1. Hydrogeochemical and stream sediment reconnaissance basic data for Meade River quadrangle, Alaska

    International Nuclear Information System (INIS)

    Field and laboratory data are presented for 515 water samples from the Meade River Quadrangle, Alaska. The samples were collected by Los Alamos National Laboratory; laboratory analysis and data reporting were performed by the Uranium Resource Evaluation Project at Oak Ridge, Tennessee

  2. Data Compendium for the Columbia River comprehensive impact assessment

    International Nuclear Information System (INIS)

    The Columbia River Comprehensive Impact Assessment (CRCIA). The CRCIA is conducted by the Pacific Northwest Laboratory (PNL). The purpose of the CRCIA is to evaluate the current human and ecological risk from the Columbia River attributable to past and present activities on the Hanford Site. Human risk will be addressed for radioactive and hazardous materials over a range of river use options. Ecological risk will be evaluated relative to the health of the current river ecosystem. The initial effort for the CRCIA is the development of a compendium of existing data on Columbia River contamination. This document provides the data compendium. It also includes a discussion of data sources, descriptions of the physical format of the data, and descriptions of the search process used to identify data

  3. Biological surveys on the Savannah River in the vicinity of the Savannah River Plant (1951-1976)

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, R. A.

    1982-04-01

    In 1951, the Academy of Natural Sciences of Philadelphia was contracted by the Savannah River Plant to initiate a long-term monitoring program in the Savannah River. The purpose of this program was to determine the effect of the Savannah River Plant on the Savannah River aquatic ecosystem. The data from this monitoring program have been computerized by the Savannah River Laboratory, and are summarized in this report. During the period from 1951-1976, 16 major surveys were conducted by the Academy in the Savannah River. Water chemistry analyses were made, and all major biological communities were sampled qualitatively during the spring and fall of each survey year. In addition, quantitative diatom data have been collected quarterly since 1953. Major changes in the Savannah River basin, in the Savannah River Plant's activities, and in the Academy sampling patterns are discussed to provide a historical overview of the biomonitoring program. Appendices include a complete taxonomic listing of species collected from the Savannah River, and summaries of the entire biological and physicochemical data base.

  4. NASA Space Radiation Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory is a NASA funded facility, delivering heavy ion beams to a target area where scientists...

  5. Lincoln Laboratory Grid

    Data.gov (United States)

    Federal Laboratory Consortium — The Lincoln Laboratory Grid (LLGrid) is an interactive, on-demand parallel computing system that uses a large computing cluster to enable Laboratory researchers to...

  6. River Restoration and Meanders

    OpenAIRE

    G. Mathias Kondolf

    2006-01-01

    Among the most visually striking river restoration projects are those that involve the creation of a new channel, often in a new alignment and generally with a form and dimensions that are different from those of the preproject channel. These channel reconstruction projects often have the objective of creating a stable, single-thread, meandering channel, even on rivers that were not historically meandering, on rivers whose sediment load and flow regime would not be consistent with such stable...

  7. Dispersion in Alluvial River

    OpenAIRE

    Ferdousi, Amena

    2014-01-01

    River pollution is the contamination of river water by pollutant being discharged directly or indirectly on it. Depending on the degree of pollutant concentration, subsequent negative environmental effects such as oxygen depletion and severe reductions in water quality may occur which affect the whole environment. River pollution can then cause a serious threat for fresh water and as well as the entire living creatures. Dispersion in natural stream is the ability of a stream to dilute soluble...

  8. Evolution of river dolphins.

    OpenAIRE

    Hamilton, H; Caballero, S.; Collins, A. G.; Brownell, R. L.

    2001-01-01

    The world's river dolphins (Inia, Pontoporia, Lipotes and Platanista) are among the least known and most endangered of all cetaceans. The four extant genera inhabit geographically disjunct river systems and exhibit highly modified morphologies, leading many cetologists to regard river dolphins as an unnatural group. Numerous arrangements have been proposed for their phylogenetic relationships to one another and to other odontocete cetaceans. These alternative views strongly affect the biogeog...

  9. Down to the River

    DEFF Research Database (Denmark)

    Wessels, Josepha Ivanka

    2015-01-01

    Currently there is no coherent or sustainable water cooperation among the five states—Israel, Jordan, Lebanon, Palestinian territories and Syria—that share the Jordan River. Why do people not cooperate on sustainable river basin management, even if it seems the most rational course from the...... illustrate hydropolitics in praxis, because the political future of this particular area in many respects affects the sustainable future of the Jordan River Basin and the entire Levant....

  10. The Ebro river basin

    OpenAIRE

    Darbra Roman, Rosa Maria

    2011-01-01

    River basins worldwide are under pressure from economic activities. In Europe, the two main factors hindering the achievement of good chemical and ecological status of European river basins are pollution, mainly coming from agriculture, and hydromorphology (e.g. for navigation, hydroelectricity and flood control). The economic activities affect the chemical and ecological status of rivers, lakes and groundwater and deplete available soil, sediments and water resources. The w...

  11. Road Transportable Analytical Laboratory system

    International Nuclear Information System (INIS)

    This developmental effort clearly shows that a Road Transportable Analytical Laboratory System is a worthwhile and achievable goal. The RTAL is designed to fully analyze (radioanalytes, and organic and inorganic chemical analytes) 20 samples per day at the highest levels of quality assurance and quality control. It dramatically reduces the turnaround time for environmental sample analysis from 45 days (at a central commercial laboratory) to 1 day. At the same time each RTAL system will save the DOE over $12 million per year in sample analysis costs compared to the costs at a central commercial laboratory. If RTAL systems were used at the eight largest DOE facilities (at Hanford, Savannah River, Fernald, Oak Ridge, Idaho, Rocky Flats, Los Alamos, and the Nevada Test Site), the annual savings would be $96,589,000. The DOE's internal study of sample analysis needs projects 130,000 environmental samples requiring analysis in FY 1994, clearly supporting the need for the RTAL system. The cost and time savings achievable with the RTAL system will accelerate and improve the efficiency of cleanup and remediation operations throughout the DOE complex

  12. Progress report: Physics Division, 1982 April 1 - June 30

    International Nuclear Information System (INIS)

    Nuclear physics studies that took place at Chalk River Nuclear Laboratories during the second quarter of 1982 are described, as well as work in solid state and theoretical physics. The MP Tandem accelerator was shut down to prepare for the installation of a superconducting cyclotron. Computer codes developed during the period and the operation of the computer facilities are described

  13. Dosimetric research at CRNL

    International Nuclear Information System (INIS)

    This paper gives a broad overview of dosimetric research being carried out at Chalk River Nuclear Laboratories. At the time of the report this research group consisted of 8 professionals and approximately 20 support staff. Areas of research discussed are: 1) dosimetry service; 2) dosimeter and monitor development; and 3) dosimetry calculations

  14. A review of analytical techniques for the determination of carbon-14 in environmental samples

    International Nuclear Information System (INIS)

    This report contains a brief summary of analytical techniques commonly used for the determination of radiocarbon in a variety of environmental samples. Details of the applicable procedures developed and tested in the Environmental Research Branch at Chalk River Laboratories are appended

  15. Materials R and D with neutron beams - how the NRU reactor serves Canada further as a unique resource for science and industry

    International Nuclear Information System (INIS)

    This presentation discusses the use of NRU reactor for materials research and development with neutron beams at the Canadian Neutron Beam Centre at the Chalk River Laboratories. The facility has 5 beams for research and development on hard materials, 1 beam for research and development on nano-film and 1 beam for research and development on nano-solution, still under development.

  16. Materials R and D with neutron beams - how the NRU reactor serves Canada further as a unique resource for science and industry

    Energy Technology Data Exchange (ETDEWEB)

    Root, J. [National Research Council Canada, Canadian Neutron Beam Centre, Ottawa, Ontario (Canada)

    2010-07-01

    This presentation discusses the use of NRU reactor for materials research and development with neutron beams at the Canadian Neutron Beam Centre at the Chalk River Laboratories. The facility has 5 beams for research and development on hard materials, 1 beam for research and development on nano-film and 1 beam for research and development on nano-solution, still under development.

  17. Progress report - Physical and Environmental Sciences - TASCC Division -1995 January 1 to June 30

    International Nuclear Information System (INIS)

    Included in this progress report of the TASCC division at Chalk River Nuclear Laboratories is the research and development being carried out at this time and a listing of the relevant publications, reports. lectures and conference contributions. 15 tabs. 19 figs

  18. Progress report physics division, 1983 July 1 - December 31

    International Nuclear Information System (INIS)

    This report summarizes work carried out during the last half of 1983 in the Physics Division of the Chalk River Nuclear Laboratories in the areas of superconducting cyclotron facility development, nuclear physics research, applied physics, solid state physics, and applied mathematics and computation

  19. AECL research programs in life sciences

    International Nuclear Information System (INIS)

    The present report summarizes the current research activities in life sciences in the Atomic Energy of Canada Limited-Research Company. The research is carried out at its two main research sites: the Chalk River Nuclear Laboratories and the Whiteshell Nuclear Research Establishment. The summaries cover the following areas of research: radiation biology, medical biophysics, epidemiology, environmental research and dosimetry. (author)

  20. An isotope separation magnet for the injector test experiment (MITE)

    International Nuclear Information System (INIS)

    A magnet has been designed for space-charge neutralization studies on the Injector Test Experiment at the Chalk River Nuclear Laboratories. Augmented by suitable collectors, the magnet could also be used for pilot-scale isotope separations. The present report documents the design of this particular magnet and illustrates the process of designing beam transport magnets in general