Science.gov

Sample records for nuclear waste repositories

  1. Hydrologic issues associated with nuclear waste repositories

    NASA Astrophysics Data System (ADS)

    Tsang, Chin-Fu; Neretnieks, Ivars; Tsang, Yvonne

    2015-09-01

    Significant progress in hydrology, especially in subsurface flow and solute transport, has been made over the last 35 years because of sustained interest in underground nuclear waste repositories. The present paper provides an overview of the key hydrologic issues involved, and to highlight advances in their understanding and treatment because of these efforts. The focus is not on the development of radioactive waste repositories and their safety assessment, but instead on the advances in hydrologic science that have emerged from such studies. Work and results associated with three rock types, which are being considered to host the repositories, are reviewed, with a different emphasis for each rock type. The first rock type is fractured crystalline rock, for which the discussion will be mainly on flow and transport in saturated fractured rock. The second rock type is unsaturated tuff, for which the emphasis will be on flow from the shallow subsurface through the unsaturated zone to the repository. The third rock type is clay-rich formations, whose permeability is very low in an undisturbed state. In this case, the emphasis will be on hydrologic issues that arise from mechanical and thermal disturbances; i.e., on the relevant coupled thermo-hydro-mechanical processes. The extensive research results, especially those from multiyear large-scale underground research laboratory investigations, represent a rich body of information and data that can form the basis for further development in the related areas of hydrologic research.

  2. Constructibility issues associated with a nuclear waste repository in basalt

    SciTech Connect

    Turner, D.A.

    1981-12-04

    This report contains the text and slide reproductions of a speech on nuclear waste disposal in basalt. The presentation addresses the layout of repository access shafts and subsurface facilities resulting from the conceptual design of a nuclear repository in basalt. The constructibility issues that must be resolved prior to construction are described. (DMC)

  3. Siting Patterns of Nuclear Waste Repositories.

    ERIC Educational Resources Information Center

    Solomon, Barry D.; Shelley, Fred M.

    1988-01-01

    Provides an inventory of international radioactive waste-management policies and repository siting decisions for North America, Central and South America, Europe, Asia, and Africa. This discussion stresses the important role of demographic, geologic, and political factors in siting decisions. (Author/BSR)

  4. Public reactions to nuclear waste: Citizens' views of repository siting

    SciTech Connect

    Rosa, E.A.

    1993-01-01

    This book presents revised and updated papers from a panel of social scientists, at the 1989 AAAS meetings, that examined the public's reactions to nuclear waste disposal and the repository siting process. The papers report the results of original empirical research on citizens' views of nuclear waste repository siting. Topics covered include the following: content analysis of public testimony; sources of public concern about nuclear waste disposal in Texas agricultural communities; local attitudes toward high-level waste repository at Hanford; perceived risk and attitudes toward nuclear wastes; attitudes of Nevada urban residents toward a nuclear waste repository; attitudes of rural community residents toward a nuclear waste respository. An introductory chapter provides background and context, and a concluding chapter summarizes the implications of the reports. Two additional chapters cover important features of high-level waste disposal: long term trends in public attitudes toward nuclear energy and nuclear waste policy and assessment of the effects on the Los Vegas convention business if a high-level nuclear waste depository were sited in Nevada.

  5. Modeling transient heat transfer in nuclear waste repositories.

    PubMed

    Yang, Shaw-Yang; Yeh, Hund-Der

    2009-09-30

    The heat of high-level nuclear waste may be generated and released from a canister at final disposal sites. The waste heat may affect the engineering properties of waste canisters, buffers, and backfill material in the emplacement tunnel and the host rock. This study addresses the problem of the heat generated from the waste canister and analyzes the heat distribution between the buffer and the host rock, which is considered as a radial two-layer heat flux problem. A conceptual model is first constructed for the heat conduction in a nuclear waste repository and then mathematical equations are formulated for modeling heat flow distribution at repository sites. The Laplace transforms are employed to develop a solution for the temperature distributions in the buffer and the host rock in the Laplace domain, which is numerically inverted to the time-domain solution using the modified Crump method. The transient temperature distributions for both the single- and multi-borehole cases are simulated in the hypothetical geological repositories of nuclear waste. The results show that the temperature distributions in the thermal field are significantly affected by the decay heat of the waste canister, the thermal properties of the buffer and the host rock, the disposal spacing, and the thickness of the host rock at a nuclear waste repository.

  6. Modeling transient heat transfer in nuclear waste repositories.

    PubMed

    Yang, Shaw-Yang; Yeh, Hund-Der

    2009-09-30

    The heat of high-level nuclear waste may be generated and released from a canister at final disposal sites. The waste heat may affect the engineering properties of waste canisters, buffers, and backfill material in the emplacement tunnel and the host rock. This study addresses the problem of the heat generated from the waste canister and analyzes the heat distribution between the buffer and the host rock, which is considered as a radial two-layer heat flux problem. A conceptual model is first constructed for the heat conduction in a nuclear waste repository and then mathematical equations are formulated for modeling heat flow distribution at repository sites. The Laplace transforms are employed to develop a solution for the temperature distributions in the buffer and the host rock in the Laplace domain, which is numerically inverted to the time-domain solution using the modified Crump method. The transient temperature distributions for both the single- and multi-borehole cases are simulated in the hypothetical geological repositories of nuclear waste. The results show that the temperature distributions in the thermal field are significantly affected by the decay heat of the waste canister, the thermal properties of the buffer and the host rock, the disposal spacing, and the thickness of the host rock at a nuclear waste repository. PMID:19376651

  7. Environmental Degradation of Materials for Nuclear Waste Repositories Engineered Barriers

    SciTech Connect

    Rebak, R B

    2006-12-24

    Several countries are considering geological repositories for the storage of nuclear waste. Most of the environments for these repositories will be reducing in nature, except for the repository in the US, which is going to be oxidizing. For the reducing repositories, alloys such as carbon steel, copper, stainless steels and titanium are being evaluated. For the repository in the US, some of the most corrosion resistant commercially available alloys are being investigated. This paper presents a summary of the behavior of the different materials under consideration for the repositories and the current understanding of the degradation modes of the proposed alloys in ground water environments from the point of view of general corrosion, localized corrosion and environmentally assisted cracking.

  8. Selection of Corrosion Resistant Materials for Nuclear Waste Repositories

    SciTech Connect

    R.B. Rebak

    2006-08-28

    Several countries are considering geological repositories to dispose of nuclear waste. The environment of most of the currently considered repositories will be reducing in nature, except for the repository in the US, which is going to be oxidizing. For the reducing repositories, alloys such as carbon steel, stainless steels and titanium are being evaluated. For the repository in the US, some of the most corrosion resistant commercially available alloys are being investigated. This paper presents a summary of the behavior of the different materials under consideration for the repositories and the current understanding of the degradation modes of the proposed alloys in ground water environments from the point of view of general corrosion, localized corrosion and environmentally assisted cracking.

  9. Selection of Corrosion Resistant Materials for Nuclear Waste Repositories

    SciTech Connect

    Rebak, R B

    2006-06-01

    Several countries are considering geological repositories to dispose of nuclear waste. The environment of most of the currently considered repositories will be reducing in nature, except for the repository in the US, which is going to be oxidizing. For the reducing repositories alloys such as carbon steel, stainless steels and titanium are being evaluated. For the repository in the US, some of the most corrosion resistant commercially available alloys are being investigated. This paper presents a summary of the behavior of the different materials under consideration for the repositories and the current understanding of the degradation modes of the proposed alloys in ground water environments from the point of view of general corrosion, localized corrosion and environmentally assisted cracking.

  10. Thermohydeologic Behavior at the Potential Yucca Mountain Nuclear Waste Repository

    SciTech Connect

    Buscheck, T.A.; Rosenburg, N.D.; Gansemer, J.; Sun, Y.

    2000-02-17

    Radioactive decay of high-level nuclear waste emplaced in a Yucca Mountain repository will produce an initial heat flux on the order of 30 to 50 times the heat flux in the Geysers geothermal reservoir in California (Hardin et al., 1998). Even though the rate of heat production decreases rapidly with time after emplacement, this heat flux will change the thermal and hydrologic environment, affecting both the host rock and conditions within the drifts in ways significant to key repository performance variables.

  11. Ventilation planning for a prospective nuclear waste repository

    SciTech Connect

    Wallace, K.G. Jr.

    1987-12-31

    In 1982, the US Congress passed the Nuclear Waste Policy Act to provide for the development of underground repositories for spent nuclear fuel. This development will be managed by the United States Department of Energy. In 1986, the President selected three areas for site characterization to determine their suitability for the development of an underground repository; those sites were: (1) A site in volcanic tuff located at Yucca Mountain in Nevada, (2) a site in bedded salt located in Deaf Smith County in Texas, and (3) a site in basalt located in Hanford, Washington. At present conceptual repository designs are being developed for each site. A key element of a repository design is the underground ventilation system required to support construction, nuclear waste emplacement, and potential waste retrieval. This paper describes the preliminary ventilation systems designed for the repository in tuff. The concept provides separate ventilation systems for the construction and waste emplacement activities. The paper further describes the means by which acceptable environmental conditions will be re-established to allow re-entry into previously closed rooms for the purpose of inspection, maintenance or retrieval.

  12. Expected brine movement at potential nuclear waste repository salt sites

    SciTech Connect

    McCauley, V.S.; Raines, G.E.

    1987-08-01

    The BRINEMIG brine migration code predicts rates and quantities of brine migration to a waste package emplaced in a high-level nuclear waste repository in salt. The BRINEMIG code is an explicit time-marching finite-difference code that solves a mass balance equation and uses the Jenks equation to predict velocities of brine migration. Predictions were made for the seven potentially acceptable salt sites under consideration as locations for the first US high-level nuclear waste repository. Predicted total quantities of accumulated brine were on the order of 1 m/sup 3/ brine per waste package or less. Less brine accumulation is expected at domal salt sites because of the lower initial moisture contents relative to bedded salt sites. Less total accumulation of brine is predicted for spent fuel than for commercial high-level waste because of the lower temperatures generated by spent fuel. 11 refs., 36 figs., 29 tabs.

  13. Hydrothermal ore deposit and geothermal analogs of nuclear waste repositories

    SciTech Connect

    Hackbarth, C.J.

    1985-01-01

    Hydrothermal ore deposits and active geothermal systems can provide important information on the response of a rock/ground water system to the emplacement of hot, radioactive nuclear waste. Congress has mandated that the first deep geologic repository be licensed by 1998, so that scientific investigation must be completed in a relatively short time. Laboratory studies are sometimes too short and on too small a scale to adequately simulate the geologic environment over thousands of years. Computer models are often highly simplified. Fortunately, data from the field of economic geology can help scientist anticipate future nuclear waste repository behaviors in a complex environment over long periods of time. Some phenomena in ore deposits are direct parallels to possible repository phenomena. Some ore and gangue minerals show colloidal textures, indicating that colloids may contribute to radionuclide redistribution in a repository. Wall rock alteration in ore deposits indicates the types of alteration to be expected in a repository. In addition to individual analogous phenomena, hydrothermal convection may develop in the ground water after emplacement of waste. Primary dispersion halos, paragenetic relationships, and fluid inclusion data from ore deposits can help to predict the size, shape, and duration of convection cells which might be expected around a repository. Such studies might also identify the significant effects of complex coupling between thermal, hydrological, chemical, and mechanical factors.

  14. Can clays ensure nuclear waste repositories?

    PubMed

    Zaoui, A; Sekkal, W

    2015-03-06

    Research on argillite as a possible host rock for nuclear waste disposal is still an open subject since many issues need to be clarified. In the Underground Research Laboratories constructed for this purpose, a damaged zone around the excavation has been systematically observed and characterized by the appearance of micro-fissures. We analyse here -at nanoscale level- the calcite/clay assembly, the main constituents of argillite, under storage conditions and show the fragility of the montmorillonite with respect to calcite. Under anisotropic stress, we have observed a shear deformation of the assembly with the presence of broken bonds in the clay mineral, localised in the octahedral rather than the tetrahedral layers. The stress/strain curve leads to a failure strength point at 18.5 MPa. The obtained in-plane response of the assembly to perpendicular deformation is characterized by smaller perpendicular moduli Ez = 48.28 GPa compared to larger in-plane moduli Ex = 141.39 GPa and Ey = 134.02 GPa. Our calculations indicate the instability of the assembly without water molecules at the interface in addition to an important shear deformation.

  15. Can clays ensure nuclear waste repositories?

    NASA Astrophysics Data System (ADS)

    Zaoui, A.; Sekkal, W.

    2015-03-01

    Research on argillite as a possible host rock for nuclear waste disposal is still an open subject since many issues need to be clarified. In the Underground Research Laboratories constructed for this purpose, a damaged zone around the excavation has been systematically observed and characterized by the appearance of micro-fissures. We analyse here -at nanoscale level- the calcite/clay assembly, the main constituents of argillite, under storage conditions and show the fragility of the montmorillonite with respect to calcite. Under anisotropic stress, we have observed a shear deformation of the assembly with the presence of broken bonds in the clay mineral, localised in the octahedral rather than the tetrahedral layers. The stress/strain curve leads to a failure strength point at 18.5 MPa. The obtained in-plane response of the assembly to perpendicular deformation is characterized by smaller perpendicular moduli Ez = 48.28 GPa compared to larger in-plane moduli Ex = 141.39 GPa and Ey = 134.02 GPa. Our calculations indicate the instability of the assembly without water molecules at the interface in addition to an important shear deformation.

  16. Can clays ensure nuclear waste repositories?

    PubMed Central

    Zaoui, A.; Sekkal, W.

    2015-01-01

    Research on argillite as a possible host rock for nuclear waste disposal is still an open subject since many issues need to be clarified. In the Underground Research Laboratories constructed for this purpose, a damaged zone around the excavation has been systematically observed and characterized by the appearance of micro-fissures. We analyse here -at nanoscale level- the calcite/clay assembly, the main constituents of argillite, under storage conditions and show the fragility of the montmorillonite with respect to calcite. Under anisotropic stress, we have observed a shear deformation of the assembly with the presence of broken bonds in the clay mineral, localised in the octahedral rather than the tetrahedral layers. The stress/strain curve leads to a failure strength point at 18.5 MPa. The obtained in-plane response of the assembly to perpendicular deformation is characterized by smaller perpendicular moduli Ez = 48.28 GPa compared to larger in-plane moduli Ex = 141.39 GPa and Ey = 134.02 GPa. Our calculations indicate the instability of the assembly without water molecules at the interface in addition to an important shear deformation. PMID:25742950

  17. Rock mechanics for hard rock nuclear waste repositories

    SciTech Connect

    Heuze, F.E.

    1981-09-01

    The mined geologic burial of high level nuclear waste is now the favored option for disposal. The US National Waste Terminal Storage Program designed to achieve this disposal includes an extensive rock mechanics component related to the design of the wastes repositories. The plan currently considers five candidate rock types. This paper deals with the three hard rocks among them: basalt, granite, and tuff. Their behavior is governed by geological discontinuities. Salt and shale, which exhibit behavior closer to that of a continuum, are not considered here. This paper discusses both the generic rock mechanics R and D, which are required for repository design, as well as examples of projects related to hard rock waste storage. The examples include programs in basalt (Hanford/Washington), in granitic rocks (Climax/Nevada Test Site, Idaho Springs/Colorado, Pinawa/Canada, Oracle/Arizona, and Stripa/Sweden), and in tuff (Nevada Test Site).

  18. Double Diffusive Natural Convection in a Nuclear Waste Repository

    SciTech Connect

    Hao, Y; Nitao, J; Buscheck, T A; Sun, Y

    2006-02-03

    In this study, we conduct a two-dimensional numerical analysis of double diffusive natural convection in an emplacement drift for a nuclear waste repository. In-drift heat and moisture transport is driven by combined thermal- and compositional-induced buoyancy forces. Numerical results demonstrate buoyancy-driven convective flow patterns and configurations during both repository heat-up and cool-down phases. It is also shown that boundary conditions, particularly on the drip-shield surface, have strong impacts on the in-drift convective flow and transport.

  19. Double Diffusive Natural Convection in a Nuclear Waste Repository

    SciTech Connect

    Hao, Y; Nitao, J J; Buscheck, T A; Sun, Y

    2006-07-24

    In this study, we conduct a two dimensional numerical analysis of double diffusive natural convection in an emplacement drift for a nuclear waste repository. In-drift heat and moisture transport is driven by combined thermal- and compositional-induced buoyancy forces. Numerical results demonstrate buoyancy-driven convective flow patterns and configurations during both repository heat-up and cool-down phases. It is also shown that boundary conditions, particularly on the drip-shield surface, have a strong impact on in-drift convective flow and transport.

  20. Double Diffusive Natural Convection in a Nuclear Waste Repository

    SciTech Connect

    Y. Hao; J. Nitao; T.A. Buscheck; Y. Sun

    2006-03-28

    In this study, we conduct a two-dimensional numerical analysis of double diffusive natural convection in an emplacement drift for a nuclear waste repository. In-drift heat and moisture transport is driven by combined thermal- and compositional-induced buoyancy forces. Numerical results demonstrate buoyancy-driven convective flow patterns and configurations during both repository heat-up and cool-down phases. It is also shown that boundary conditions, particularly on the drip-shield surface, have strong impacts on the in-drift convective flow and transport.

  1. Local acceptance of a high-level nuclear waste repository.

    PubMed

    Sjöberg, Lennart

    2004-06-01

    The siting of nuclear waste facilities has been very difficult in all countries. Recent experience in Sweden indicates, however, that it may be possible, under certain circumstances, to gain local support for the siting of a high-level nuclear waste (HLNW) repository. The article reports on a study of attitudes and risk perceptions of people living in four municipalities in Sweden where HLNW siting was being intensely discussed at the political level, in media, and among the public. Data showed a relatively high level of consensus on acceptability of at least further investigation of the issue; in two cases local councils have since voted in favor of a go-ahead, and in one case only a very small majority defeated the issue. Models of policy attitudes showed that these were related to attitude to nuclear power, attributes of the perceived HLNW risk, and trust. Factors responsible for acceptance are discussed at several levels. One is the attitude to nuclear power, which is becoming more positive, probably because no viable alternatives are in sight. Other factors have to do with the extensive information programs conducted in these municipalities, and with the logical nature of the conclusion that they would be good candidates for hosting the national HLNW repository.

  2. Yucca Mountain nuclear waste repository prompts heated congressional hearing

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2011-11-01

    Although the final report of the Blue Ribbon Commission on America's Nuclear Future is not expected until January 2012, the tentative conclusions of the commission's draft report were dissected during a recent joint hearing by two subcommittees of the House of Representatives' Committee on Science, Space, and Technology. Among the more heated issues debated at the hearing was the fate of the stalled Yucca Mountain nuclear waste repository in Nevada. The Blue Ribbon Commission's (BRC) draft report includes recommendations for managing nuclear waste and for developing one or more permanent deep geological repositories and interim storage facilities, but the report does not address the future of Yucca Mountain. The BRC charter indicates that the commission is to "conduct a comprehensive review of policies for managing the back end of the nuclear fuel cycle." However, the draft report states that the commission was not asked to consider, and therefore did not address, several key issues. "We have not rendered an opinion on the suitability of the Yucca Mountain site or on the request to withdraw the license application for Yucca Mountain," the draft report states.

  3. Monitor for detecting nuclear waste leakage in a subsurface repository

    NASA Astrophysics Data System (ADS)

    Klainer, S.; Hirschfeld, T.; Bowman, H.; Milanovich, F.; Perry, D.; Johnson, D.

    1980-11-01

    A remote fiber optics system is employed in conjunction with the coprecipitation enhanced fluorimetry technique to detect radioactive waste leakage. An in situ monitoring capability using fiber optics to effect communication between the instrumentation and the sample is demonstrated. The sample is an actinide or a tracer material leaking from an underground nuclear waste repository into the ground water. A lanthanide (which is an excellent fluorescent agent), actinide or other species which does not radiation damage is chosen as the tracer to maximize sensitivity, specificity, and relevance. Taggants having variable excitation and emission wavelengths create a need for an acromatic retroreflective fiber coupler. This was done using the geometrical properties of the fiber to design a coupler requiring no dichroics or glossy energy splitting surfaces.

  4. Geotechnical support and topical studies for nuclear waste geologic repositories

    SciTech Connect

    Not Available

    1989-01-01

    The present report lists the technical reviews and comments made during the fiscal year 1988 and summarizes the technical progress of the topical studies. In the area of technical assistance, there were numerous activities detailed in the next section. These included 24 geotechnical support activities, including reviews of 6 Study Plans (SP) and participation in 6 SP Review Workshops, review of one whole document Site Characterization Plan (SCP) and participation in the Assembled Document SCP Review Workshops by 6 LBL reviewers; the hosting of a DOE program review, the rewriting of the project statement of work, 2 trips to technical and planning meetings; preparation of proposed work statements for two new topics for DOE, and 5 instances of technical assistance to DOE. These activities are described in a Table in the following section entitled Geoscience Technical Support for Nuclear Waste Geologic Repositories.''

  5. Hydrogeologic effects of natural disruptive events on nuclear waste repositories

    SciTech Connect

    Davis, S.N.

    1980-06-01

    Some possible hydrogeologic effects of disruptive events that may affect repositories for nuclear wastte are described. A very large number of combinations of natural events can be imagined, but only those events which are judged to be most probable are covered. Waste-induced effects are not considered. The disruptive events discussed above are placed into four geologic settings. Although the geology is not specific to given repository sites that have been considered by other agencies, the geology has been generalized from actual field data and is, therefore, considered to be physically reasonable. The geologic settings considered are: (1) interior salt domes of the Gulf Coast, (2) bedded salt of southeastern New Mexico, (3) argillaceous rocks of southern Nevanda, and (4) granitic stocks of the Basin and Range Province. Log-normal distributions of permeabilities of rock units are given for each region. Chapters are devoted to: poresity and permeability of natural materials, regional flow patterns, disruptive events (faulting, dissolution of rock forming minerals, fracturing from various causes, rapid changes of hydraulic regimen); possible hydrologic effects of disruptive events; and hydraulic fracturing.

  6. Development of reference conditions for geologic repositories for nuclear waste in the USA

    SciTech Connect

    Raines, G. E.; Rickertsen, L. D.; Claiborne, H. C.; McElroy, J. L.; Lynch, R. W.

    1980-10-01

    Activities to determine interim reference conditions for temperatures, pressure, fluid, chemical, and radiation environments that are expected to exist in commercial and defense high-level nuclear waste and spent fuel repositories in salt, basalt, tuff, granite, and shale are summarized. These interim conditions are being generated by the Reference Repository Conditions Interface Working Groups (RRC-IWG), an ad hoc IWG established by the National Waste Terminal Storage Program's (NWTS) Isolation Interface Control Board (I-ICB).

  7. Fault Frictional Stability in a Nuclear Waste Repository

    NASA Astrophysics Data System (ADS)

    Orellana, Felipe; Violay, Marie; Scuderi, Marco; Collettini, Cristiano

    2016-04-01

    Exploitation of underground resources induces hydro-mechanical and chemical perturbations in the rock mass. In response to such disturbances, seismic events might occur, affecting the safety of the whole engineering system. The Mont Terri Rock Laboratory is an underground infrastructure devoted to the study of geological disposal of nuclear waste in Switzerland. At the site, it is intersected by large fault zones of about 0.8 - 3 m in thickness and the host rock formation is a shale rock named Opalinus Clay (OPA). The mineralogy of OPA includes a high content of phyllosilicates (50%), quartz (25%), calcite (15%), and smaller proportions of siderite and pyrite. OPA is a stiff, low permeable rock (2×10-18 m2), and its mechanical behaviour is strongly affected by the anisotropy induced by bedding planes. The evaluation of fault stability and associated fault slip behaviour (i.e. seismic vs. aseismic) is a major issue in order to ensure the long-term safety and operation of the repository. Consequently, experiments devoted to understand the frictional behaviour of OPA have been performed in the biaxial apparatus "BRAVA", recently developed at INGV. Simulated fault gouge obtained from intact OPA samples, were deformed at different normal stresses (from 4 to 30 MPa), under dry and fluid-saturated conditions. To estimate the frictional stability, the velocity-dependence of friction was evaluated during velocity steps tests (1-300 μm/s). Slide-hold-slide tests were performed (1-3000 s) to measure the amount of frictional healing. The collected data were subsequently modelled with the Ruina's slip dependent formulation of the rate and state friction constitutive equations. To understand the deformation mechanism, the microstructures of the sheared gouge were analysed. At 7 MPa normal stress and under dry conditions, the friction coefficient decreased from a peak value of μpeak,dry = 0.57 to μss,dry = 0.50. Under fluid-saturated conditions and same normal stress, the

  8. Climate considerations in long-term safety assessments for nuclear waste repositories.

    PubMed

    Näslund, Jens-Ove; Brandefelt, Jenny; Liljedahl, Lillemor Claesson

    2013-05-01

    For a deep geological repository for spent nuclear fuel planned in Sweden, the safety assessment covers up to 1 million years. Climate scenarios range from high-end global warming for the coming 100 000 years, through deep permafrost, to large ice sheets during glacial conditions. In contrast, in an existing repository for short-lived waste the activity decays to low levels within a few tens of thousands of years. The shorter assessment period, 100 000 years, requires more focus on climate development over the coming tens of thousands of years, including the earliest possibility for permafrost growth and freezing of the engineered system. The handling of climate and climate change in safety assessments must be tailor-made for each repository concept and waste type. However, due to the uncertain future climate development on these vast time scales, all safety assessments for nuclear waste repositories require a range of possible climate scenarios.

  9. Debate heats up over potential Interim Nuclear Waste Repository, as studies of Yucca Mountain continue

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    With spent nuclear fuel piling up at power plants around the United States, and with a potential permanent nuclear waste repository at Nevada's Yucca Mountain not scheduled to accept waste until 11 years from now in the year 2010, the nuclear energy industry and many members of Congress have renewed their push to establish an interim repository at the adjacent Nevada Test Site of nuclear bombs.At a sometimes contentious March 12 hearing to consider the Nuclear Waste Policy Act of 1999 (House Resolution 45) that would require an interim facility to begin accepting waste in 2003, bill cosponsor Rep. Jim Barton (R-Tex.) told Energy Secretary Bill Richardson that he preferred that Congress and the Clinton Administration negotiate rather than fight over the measure.

  10. Backfill composition for secondary barriers in nuclear waste repositories

    DOEpatents

    Beall, G.W.; Allard, B.M.

    1980-05-30

    A backfill composition for sorbing and retaining hazardous elements of nuclear wastes comprises 50 to 70% by weight of quartz, 10 to 30% by weight of montmorillonite, 1 to 10% by weight of phosphate mineral, 1 to 10% by weight of ferrous mineral, 1 to 10% by weight of sulfate mineral and 1 to 10% by weight of attapulgite.

  11. Backfill composition for secondary barriers in nuclear waste repositories

    DOEpatents

    Beall, Gary W.; Allard, Bert M.

    1982-01-01

    A backfill composition for sorbing and retaining hazardous elements of nuclear wastes comprises 50-70% by weight of quartz, 10-30% by weight of montmorillonite, 1-10% by weight of phosphate mineral, 1-10% by weight of ferrous mineral, 1-10% by weight of sulfate mineral and 1-10% by weight of attapulgite.

  12. Retrieval effects on ventilation and cooling requirements for a nuclear waste repository

    SciTech Connect

    Hambley, D.F.

    1985-01-01

    The Nuclear Waste Policy Act of 1982 (Public Law 97-425) and the regulations promulgated in Title 10, Part 60 of the Code of Federal Regulations (10CFR60) by the US Nuclear Regulatory Commission (NRC) for an underground repository for spent fuel and high level nuclear waste (HLW) require that it is possible to retrieve waste, for whatever reason, from such a facility for a period of 50 years from initial storage or until the completion of the performance confirmation period, whichever comes first. This paper considers the effects that the retrievability option mandates on ventilation and cooling systems required for normal repository operations. An example is given for a hypothetical repository in salt. 18 refs., 1 tab.

  13. Engineered barrier development for a nuclear waste repository in basalt: an integration of current knowledge

    SciTech Connect

    Smith, M.J.

    1980-05-01

    This document represents a compilation of data and interpretive studies conducted as part of the engineered barriers program of the Basalt Waste Isolation Project. The overall objective of these studies is to provide information on barrier system designs, emplacement and isolation techniques, and chemical reactions expected in a nuclear waste repository located in the basalts underlying the Hanford Site within the state of Washington. Backfills, waste-basalt interactions, sorption, borehole plugging, etc., are among the topics discussed.

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

    SciTech Connect

    Apps, J.A.

    1995-09-01

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

  15. Anticipated Degradation Modes of Metallic Engineered Barriers for High-Level Nuclear Waste Repositories

    NASA Astrophysics Data System (ADS)

    Rodríguez, Martín A.

    2014-03-01

    Metallic engineered barriers must provide a period of absolute containment to high-level radioactive waste in geological repositories. Candidate materials include copper alloys, carbon steels, stainless steels, nickel alloys, and titanium alloys. The national programs of nuclear waste management have to identify and assess the anticipated degradation modes of the selected materials in the corresponding repository environment, which evolves in time. Commonly assessed degradation modes include general corrosion, localized corrosion, stress-corrosion cracking, hydrogen-assisted cracking, and microbiologically influenced corrosion. Laboratory testing and modeling in metallurgical and environmental conditions of similar and higher aggressiveness than those expected in service conditions are used to evaluate the corrosion resistance of the materials. This review focuses on the anticipated degradation modes of the selected or reference materials as corrosion-resistant barriers in nuclear repositories. These degradation modes depend not only on the selected alloy but also on the near-field environment. The evolution of the near-field environment varies for saturated and unsaturated repositories considering backfilled and unbackfilled conditions. In saturated repositories, localized corrosion and stress-corrosion cracking may occur in the initial aerobic stage, while general corrosion and hydrogen-assisted cracking are the main degradation modes in the anaerobic stage. Unsaturated repositories would provide an oxidizing environment during the entire repository lifetime. Microbiologically influenced corrosion may be avoided or minimized by selecting an appropriate backfill material. Radiation effects are negligible provided that a thick-walled container or an inner shielding container is used.

  16. Seismic design of low-level nuclear waste repositories and toxic waste management facilities

    SciTech Connect

    Chung, D.H.; Bernreuter, D.L.

    1984-05-08

    Identification of the elements of typical hazardous waste facilities (HFWs) that are the major contributors to the risk are focussed on as the elements which require additional considerations in the design and construction of low-level nuclear waste management repositories and HWFs. From a recent study of six typical HWFs it was determined that the factors that contribute most to the human and environmental risk fall into four basic categories: geologic and seismological conditions at each HWF; engineered structures at each HWF; environmental conditions at each HWF; and nature of the material being released. In selecting and carrying out the six case studies, three groups of hazardous waste facilities were examined: generator industries which treat or temporarily store their own wastes; generator facilities which dispose of their own hazardous wastes on site; and industries in the waste treatment and disposal business. The case studies have a diversity of geologic setting, nearby settlement patterns, and environments. Two sites are above a regional aquifer, two are near a bay important to regional fishing, one is in rural hills, and one is in a desert, although not isolated from nearby towns and a groundwater/surface-water system. From the results developed in the study, it was concluded that the effect of seismic activity on hazardous facilities poses a significant risk to the population. Fifteen reasons are given for this conclusion.

  17. Health Cost of a Nuclear Waste Repository, WIPP

    NASA Astrophysics Data System (ADS)

    Kula, Erhun

    1996-01-01

    The Waste Isolation Pilot Plant (WIPP), the United States of America’s first nuclear waste dumping site, has over the years generated a great deal of concern and controversy. The most sensitive aspect of this project is that it may impose serious health risks on future generations. The first leg of this project is about to be completed and at the time of writing the Department of Energy is planning to perform experiments with a small quantity of waste for operational demonstrations. If everything goes well, then towards the end of this decade large quantities of wastes will be transported to the site for disposal. This article reconsiders the health cost of this project from an economic perspective in light of recent developments in the field of social discounting. As in earlier studies, two cases of health risks are considered: total cancer and genetic deformity over a one million year cutoff period. The analysis shows that whereas ordinary discounting method wipes out the future health detriments, expressed in monetary terms, the modified discounting criterion retains a substantial proportion of such costs in economic analysis.

  18. Instrument reliability for high-level nuclear-waste-repository applications

    SciTech Connect

    Rogue, F.; Binnall, E.P.; Armantrout, G.A.

    1983-01-31

    Reliable instrumentation will be needed to evaluate the characteristics of proposed high-level nuclear-wasted-repository sites and to monitor the performance of selected sites during the operational period and into repository closure. A study has been done to assess the reliability of instruments used in Department of Energy (DOE) waste repository related experiments and in other similar geological applications. The study included experiences with geotechnical, hydrological, geochemical, environmental, and radiological instrumentation and associated data acquisition equipment. Though this paper includes some findings on the reliability of instruments in each of these categories, the emphasis is on experiences with geotechnical instrumentation in hostile repository-type environments. We review the failure modes, rates, and mechanisms, along with manufacturers modifications and design changes to enhance and improve instrument performance; and include recommendations on areas where further improvements are needed.

  19. Science Is the First Step to Siting Nuclear Waste Repositories

    NASA Astrophysics Data System (ADS)

    Neuzil, C. E.

    2014-02-01

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

  20. Panel report on coupled thermo-mechanical-hydro-chemical processes associated with a nuclear waste repository

    SciTech Connect

    Tsang, C.F.; Mangold, D.C.

    1984-07-01

    Four basic physical processes, thermal, hydrological, mechanical and chemical, are likely to occur in 11 different types of coupling during the service life of an underground nuclear waste repository. A great number of coupled processes with various degrees of importance for geological repositories were identified and arranged into these 11 types. A qualitative description of these processes and a tentative evaluation of their significance and the degree of uncertainty in prediction is given. Suggestions for methods of investigation generally include, besides theoretical work, laboratory and large scale field testing. Great efforts of a multidisciplinary nature are needed to elucidate details of several coupled processes under different temperature conditions in different geological formations. It was suggested that by limiting the maximum temperature to 100{sup 0}C in the backfill and in the host rock during the whole service life of the repository the uncertainties in prediction of long-term repository behavior might be considerably reduced.

  1. Summary of four release consequence analyses for hypothetical nuclear waste repositories in salt and granite

    SciTech Connect

    Cole, C.R.; Bond, F.W.

    1980-12-01

    Release consequence methology developed under the Assessment of Effectiveness of Geologic Isolation Systems (AEGIS) program has now been applied to four hypothetical repository sites. This paper summarizes the results of these four studies in order to demonstrate that the far-field methodology developed under the AEGIS program offers a practical approach to the post-closure safety assessment of nuclear waste repositories sited in deep continental geologic formations. The four studies are briefly described and compared according to the following general categories: physical description of the repository (size, inventory, emplacement depth); geologic and hydrologic description of the site and the conceptual hydrologic model for the site; description of release scenario; hydrologic model implementation and results; engineered barriers and leach rate modeling; transport model implementation and results; and dose model implementation and results. These studies indicate the following: numerical modeling is a practical approach to post-closure safety assessment analysis for nuclear waste repositories; near-field modeling capability needs improvement to permit assessment of the consequences of human intrusion and pumping well scenarios; engineered barrier systems can be useful in mitigating consequences for postulated release scenarios that short-circuit the geohydrologic system; geohydrologic systems separating a repository from the natural biosphere discharge sites act to mitigate the consequences of postulated breaches in containment; and engineered barriers of types other than the containment or absorptive type may be useful.

  2. High level nuclear waste repository in salt: Sealing systems status and planning report: Draft report

    SciTech Connect

    1985-09-01

    This report documents the initial conceptual design studies for a repository sealing system for a high-level nuclear waste repository in salt. The first step in the initial design studies was to review the current design level, termed schematic designs. This review identified practicality of construction and development of a design methodology as two key issues for the conceptual design. These two issues were then investigated during the initial design studies for seal system materials, seal placement, backfill emplacement, and a testing and monitoring plan. The results of these studies have been used to develop a program plan for completion of the sealing system conceptual design. 60 refs., 26 figs., 18 tabs.

  3. NWTS program criteria for mined geologic disposal of nuclear waste: repository performance and development criteria. Public draft

    SciTech Connect

    1982-07-01

    This document, DOE/NWTS-33(3) is one of a series of documents to establish the National Waste Terminal Storage (NWTS) program criteria for mined geologic disposal of high-level radioactive waste. For both repository performance and repository development it delineates the criteria for design performance, radiological safety, mining safety, long-term containment and isolation, operations, and decommissioning. The US Department of Energy will use these criteria to guide the development of repositories to assist in achieving performance and will reevaluate their use when the US Nuclear Regulatory Commission issues radioactive waste repository rules.

  4. Hydrological and thermal issues concerning a nuclear waste repository in fractured rocks

    SciTech Connect

    Wang, J.S.Y.

    1991-12-01

    The characterization of the ambient conditions of a potential site and the assessment of the perturbations induced by a nuclear waste repository require hydrological and thermal investigations of the geological formations at different spatial and temporal scales. For high-level wastes, the near-field impacts depend on the heat power of waste packages and the far-field long-term perturbations depend on the cumulative heat released by the emplaced wastes. Surface interim storage of wastes for several decades could lower the near-field impacts but would have relatively small long-term effects if spent fuels were the waste forms for the repository. One major uncertainty in the assessment of repository impacts is from the variation of hydrological properties in heterogeneous media, including the effects of fractures as high-permeability flow paths for containment migration. Under stress, a natural fracture cannot be represented by the parallel plate model. The rock surface roughness, the contact area, and the saturation state in the rock matrix could significantly change the fracture flow. In recent years, the concern of fast flow through fractures in saturated media has extended to the unsaturated zones. The interactions at different scales between fractures and matrix, between fractured matrix unites and porous units, and between formations and faults are discussed.

  5. A conceptual subsurface facility design for a high-level nuclear waste repository at Yucca Mountain

    SciTech Connect

    McKenzie, D.G., III; Bhattacharyya, K.K.; Segrest, A.M.

    1996-09-01

    The US Department of Energy is responsible for the design, construction, operation and closure of a repository in which to permanently dispose of the nation`s high level nuclear waste. In addition to the objective of safely isolating the waste inventory, the repository must provide a safe working environment for its workforce, and protect the public. The conceptual design for this facility is currently being developed. Tunnel Boring Machine will be used to excavate 228 kilometers of tunneling to construct the facility over a 30 year period. The excavation operations will be physically separated from the waste emplacement operations, and each operation will have its own dedicated ventilation system. The facility is being designed to remain open for 150 years.

  6. Consideration of criticality in a nuclear waste repository

    SciTech Connect

    Rechard, R.P.; Sanchez, L.C.; Stockman, C.T.; Ramsey, J.L. Jr.; Martell, M.

    1995-07-01

    The preliminary criticality analysis that was done suggests that the possibility of achieving critical conditions cannot be easily ruled out without looking at the geochemical process of assembly or the dynamics of the operation of a critical assembly. The evaluation of a critical assembly requires an integrated, consistent approach that includes evaluating the following: (1) the alteration rates of the layers of the container and spent fuel, (2) the transport of fissile material or neutron absorbers, and (3) the assembly mechanisms that can achieve critical conditions. The above is a non-trivial analysis and preliminary work suggests that with the loading assumed, enough fissile mass will leach from the HEU multi-purpose canisters to support a criticality. In addition, the consequences of an unpressurized Oklo type criticality would be insignificant to the performance of an unsaturated, tuff repository.

  7. Geomechanical and Thermal Effects on Moisture Flow at the Proposed Yucca Mountain Nuclear Waste Repository

    SciTech Connect

    Ofoegbu, Goodluck I.; Painter, Scott; Chen Rui; Fedors, Randall W.; Ferrill, David A

    2001-06-15

    The percolation flux through the unsaturated zone at the proposed Yucca Mountain repository for high-level nuclear waste can potentially affect (a) the occurrence and magnitude of water influx into the emplacement drifts, (b) the onset and rates of waste-package corrosion, (c) the mobilization of waste into aqueous states, and (d) the transport of radionuclides to the saturated zone. The magnitude and spatial and temporal variations of percolation flux depend on the infiltration rate but may be significantly influenced by (a) lateral diversion of flow at stratigraphic interfaces between nonwelded and welded tuffs above the repository horizon, (b) focusing of flow within or near steeply dipping fault zones, and (c) lateral diversion of flow within thermal-mechanical altered zones. Results from numerical modeling are presented to argue that (a) areas of the repository located close to and on the up-dip side of faults that intersect the Paintbrush nonwelded Tuff (PTn) would experience elevated percolation flux, irrespective of whether the faults act as flow barriers or conduits; (b) mechanical response of the rock mass to waste-generated heat will likely cause the development of laterally discontinuous zones characterized by dilation of horizontal fractures and net dilation or closure of vertical fractures; (c) areas of the repository located on the downstream side of the thermal-mechanical altered zones would experience elevated percolation flux; and (d) repository areas subjected to elevated percolation flux would experience faster rewetting of dryout zones and, thus, longer periods of wetness and elevated humidity. These results indicate that models used to predict the occurrence and magnitudes of water influx into emplacement drifts and the variations of relative humidity within the drifts need to consider the location of the drifts relative to faults that intersect the PTn and the development, geometry, and hydrological characteristics of thermal

  8. Investigating the Thermal Limit of Clay Minerals for Applications in Nuclear Waste Repository Design

    NASA Astrophysics Data System (ADS)

    Matteo, E. N.; Miller, A. W.; Kruichak, J.; Mills, M.; Tellez, H.; Wang, Y.

    2013-12-01

    Clay minerals are likely candidates to aid in nuclear waste isolation due to their low permeability, favorable swelling properties, and high cation sorption capacities. Establishing the thermal limit for clay minerals in a nuclear waste repository is a potentially important component of repository design, as flexibility of the heat load within the repository can have a major impact on the selection of repository design. For example, the thermal limit plays a critical role in the time that waste packages would need to cool before being transferred to the repository. Understanding the chemical and physical changes that occur in clay minerals at various temperatures above the current thermal limit (of 100 °C) can enable decision-makers with information critical to evaluating the potential trade-offs of increasing the thermal limit within the repository. Most critical is gaining understanding of how varying thermal conditions in the repository will impact radionuclide sorption and transport in clay materials either as engineered barriers or as disposal media. A variety of clays (illite, mixed layer illite/smectite, montmorillonite, and palygorskite) were heated for a range of temperatures between 100-500 °C. These samples were characterized by a variety of methods, including nitrogen adsorption, x-ray diffraction, thermogravimetric analysis, barium chloride exchange for cation exchange capacity (CEC), and iodide sorption. The nitrogen porosimetry shows that for all the clays, thermally-induced changes in BET surface area are dominated by collapse/creation of the microporosity, i.e. pore diameters < 17 angstroms. Changes in micro porosity (relative to no heat treatment) are most significant for heat treatments 300 °C and above. Alterations are also seen in the chemical properties (CEC, XRD, iodide sorption) of clays, and like pore size distribution changes, are most significant above 300 °C. Overall, the results imply that changes seen in pores size distribution

  9. Coupling of Nuclear Waste Form Corrosion and Radionuclide Transports in Presence of Relevant Repository Sediments

    SciTech Connect

    Wall, Nathalie A.; Neeway, James J.; Qafoku, Nikolla P.; Ryan, Joseph V.

    2015-09-30

    Assessments of waste form and disposal options start with the degradation of the waste forms and consequent mobilization of radionuclides. Long-term static tests, single-pass flow-through tests, and the pressurized unsaturated flow test are often employed to study the durability of potential waste forms and to help create models that predict their durability throughout the lifespan of the disposal site. These tests involve the corrosion of the material in the presence of various leachants, with different experimental designs yielding desired information about the behavior of the material. Though these tests have proved instrumental in elucidating various mechanisms responsible for material corrosion, the chemical environment to which the material is subject is often not representative of a potential radioactive waste repository where factors such as pH and leachant composition will be controlled by the near-field environment. Near-field materials include, but are not limited to, the original engineered barriers, their resulting corrosion products, backfill materials, and the natural host rock. For an accurate performance assessment of a nuclear waste repository, realistic waste corrosion experimental data ought to be modeled to allow for a better understanding of waste form corrosion mechanisms and the effect of immediate geochemical environment on these mechanisms. Additionally, the migration of radionuclides in the resulting chemical environment during and after waste form corrosion must be quantified and mechanisms responsible for migrations understood. The goal of this research was to understand the mechanisms responsible for waste form corrosion in the presence of relevant repository sediments to allow for accurate radionuclide migration quantifications. The rationale for this work is that a better understanding of waste form corrosion in relevant systems will enable increased reliance on waste form performance in repository environments and potentially

  10. Tectonic characterization of a potential high-level nuclear waste repository at Yucca Mountain, Nevada

    USGS Publications Warehouse

    Whitney, John W.; O'Leary, Dennis W.

    1993-01-01

    Tectonic characterization of a potential high-level nuclear waste repository at Yucca Mountain, Nevada, is needed to assess seismic and possible volcanic hazards that could affect the site during the preclosure (next 100 years) and the behavior of the hydrologic system during the postclosure (the following 10,000 years) periods. Tectonic characterization is based on assembling mapped geological structures in their chronological order of development and activity, and interpreting their dynamic interrelationships. Addition of mechanistic models and kinematic explanations for the identified tectonic processes provides one or more tectonic models having predictive power. Proper evaluation and application of tectonic models can aid in seismic design and help anticipate probable occurrence of future geologic events of significance to the repository and its design.

  11. Dynamic use of geoscience information to develop scientific understanding for a nuclear waste repository

    SciTech Connect

    Cook, N.G.W.; Tsang, C.F.

    1990-01-01

    The development and safety evaluation of a nuclear waste geologic repository require a proper scientific understanding of the site response. Such scientific understanding depends on information from a number of geoscience disciplines, including geology, geophysics, geochemistry, geomechanics and hydrogeology. The information comes in four stages: (1) general regional survey data base, (2) surface-based testing, (3) exploratory shaft testing, and (4) repository construction and evaluation. A discussion is given on the dynamic use of the information through the different stages. We point out the need for abstracting, deriving and updating a quantitative spatial and process model (QSPM) to develop a scientific understanding of site responses as a crucial element in the dynamic procedure. 2 figs.

  12. Role of geophysics in identifying and characterizing sites for high-level nuclear waste repositories.

    USGS Publications Warehouse

    Wynn, J.C.; Roseboom, E.H.

    1987-01-01

    Evaluation of potential high-level nuclear waste repository sites is an area where geophysical capabilities and limitations may significantly impact a major governmental program. Since there is concern that extensive exploratory drilling might degrade most potential disposal sites, geophysical methods become crucial as the only nondestructive means to examine large volumes of rock in three dimensions. Characterization of potential sites requires geophysicists to alter their usual mode of thinking: no longer are anomalies being sought, as in mineral exploration, but rather their absence. Thus the size of features that might go undetected by a particular method take on new significance. Legal and regulatory considerations that stem from this different outlook, most notably the requirements of quality assurance (necessary for any data used in support of a repository license application), are forcing changes in the manner in which geophysicists collect and document their data. -Authors

  13. Release and transport of gaseous C-14 from a nuclear waste repository in an unsaturated medium

    SciTech Connect

    Light, W.B.; Zwahlen, E.D.; Pigford, T.H.; Chambre, P.L.; Lee, W.W.L.

    1990-11-01

    The potential nuclear waste repository at Yucca Mountain is to be in partially saturated rock. Released radioactive gases such as {sup 14}CO{sub 2} could have a direct pathway to the biosphere. We study the release of {sup 14}C released as {sup 14}CO{sub 2} from partly failed nuclear waste containers by analyzing the flow of gas into and out of a container. We analyze the transport of released {sup 14}CO{sub 2} in an unsaturated, fractured, porous medium with gas-phase advection and dispersion. We calculate the inhalation dose to a maximally exposed individual above ground, based on some conservative assumptions about release from containers. For the assumed parameter values, a simple atmospheric diffusion model gives very small doses when compared to background radiation doses. 12 refs., 4 figs., 1 tab.

  14. Dynamic analysis and design considerations for high-level nuclear waste repositories

    SciTech Connect

    Hossain, Q.A.

    1993-09-01

    These proceedings are arranged into six broad categories: general overview of analysis and design; characterization of faulting; characterization of design ground vibratory ground motion; considerations for underground facilities; considerations for surface facilities; and guidelines for instrumentation and monitoring. Discussions are given on the relative merits and inadequacies of state-of-the-art design/analysis practices and methodologies in the seismic and dynamic analysis and design field in relation to high-level nuclear waste repositories. All papers have been processed for inclusion on the data base.

  15. Molecular hydrogen: An abundant energy source for bacterial activity in nuclear waste repositories

    NASA Astrophysics Data System (ADS)

    Libert, M.; Bildstein, O.; Esnault, L.; Jullien, M.; Sellier, R.

    A thorough understanding of the energy sources used by microbial systems in the deep terrestrial subsurface is essential since the extreme conditions for life in deep biospheres may serve as a model for possible life in a nuclear waste repository. In this respect, H 2 is known as one of the most energetic substrates for deep terrestrial subsurface environments. This hydrogen is produced from abiotic and biotic processes but its concentration in natural systems is usually maintained at very low levels due to hydrogen-consuming bacteria. A significant amount of H 2 gas will be produced within deep nuclear waste repositories, essentially from the corrosion of metallic components. This will consequently improve the conditions for microbial activity in this specific environment. This paper discusses different study cases with experimental results to illustrate the fact that microorganisms are able to use hydrogen for redox processes (reduction of O 2, NO3-, Fe III) in several waste disposal conditions. Consequences of microbial activity include: alteration of groundwater chemistry and shift in geochemical equilibria, gas production or consumption, biocorrosion, and potential modifications of confinement properties. In order to quantify the impact of hydrogen bacteria, the next step will be to determine the kinetic rate of the reactions in realistic conditions.

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

    NASA Astrophysics Data System (ADS)

    Koudelka, Tomáš; Kruis, Jaroslav

    2016-06-01

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

  17. Modeling Hydrogen-Induced Cracking of Titanium Alloys in Nuclear Waste Repository Environments

    SciTech Connect

    F. Hua; K. Mon; P. Pasupathi; G. Gordon

    2004-09-08

    This paper reviews the current understanding of hydrogen-induced cracking (HIC) of Ti Grade 7 and other relevant titanium alloys within the context of the current waste package design for the repository environmental conditions anticipated within the Yucca Mountain repository. The review concentrates on corrosion processes possible in the aqueous environments expected within this site. A brief background discussion of the relevant properties of titanium alloys, the hydrogen absorption process, and the properties of passive film on titanium alloys is presented as the basis for the subsequent discussion of model developments. The key corrosion processes that could occur are addressed individually. Subsequently, the expected corrosion performance of these alloys under the specific environmental conditions anticipated at Yucca Mountain is considered. It can be concluded that, based on the conservative modeling approaches adopted, hydrogen-induced cracking of titanium alloys will not occur under nuclear waste repository conditions since there will not be sufficient hydrogen in the alloy after 10,000 years of emplacement.

  18. Corrosion-induced gas generation in a nuclear waste repository: Reactive geochemistry and multiphase flow effect

    SciTech Connect

    Xu, T.; Senger, R.; Finsterle, S.

    2008-10-15

    Corrosion of steel canisters, stored in a repository for spent fuel and high-level nuclear wastes, leads to the generation and accumulation of hydrogen gas in the backfilled emplacement tunnels, which may significantly affect long-term repository safety. Previous studies used H{sub 2} generation rates based on the volume of the waste or canister material and the stoichiometry of the corrosion reaction. However, iron corrosion and H{sub 2} generation rates vary with time, depending on factors such as amount of iron, water availability, water contact area, and aqueous and solid chemistry. To account for these factors and feedback mechanisms, we developed a chemistry model related to iron corrosion, coupled with two-phase (liquid and gas) flow phenomena that are driven by gas-pressure buildup associated with H{sub 2} generation and water consumption. Results indicate that by dynamically calculating H{sub 2} generation rates based on a simple model of corrosion chemistry, and by coupling this corrosion reaction with two-phase flow processes, the degree and extent of gas pressure buildup could be much smaller compared to a model that neglects the coupling between flow and reactive transport mechanisms. By considering the feedback of corrosion chemistry, the gas pressure increases initially at the canister, but later decreases and eventually returns to a stabilized pressure that is slightly higher than the background pressure. The current study focuses on corrosion under anaerobic conditions for which the coupled hydrogeochemical model was used to examine the role of selected physical parameters on the H{sub 2} gas generation and corresponding pressure buildup in a nuclear waste repository. The developed model can be applied to evaluate the effect of water and mineral chemistry of the buffer and host rock on the corrosion reaction for future site-specific studies.

  19. Expected environments in high-level nuclear waste and spent fuel repositories in salt

    SciTech Connect

    Claiborne, H.C.; Rickertsen, L.D., Graham, R.F.

    1980-08-01

    The purpose of this report is to describe the expected environments associated with high-level waste (HLW) and spent fuel (SF) repositories in salt formations. These environments include the thermal, fluid, pressure, brine chemistry, and radiation fields predicted for the repository conceptual designs. In this study, it is assumed that the repository will be a room and pillar mine in a rock-salt formation, with the disposal horizon located approx. 2000 ft (610 m) below the surface of the earth. Canistered waste packages containing HLW in a solid matrix or SF elements are emplaced in vertical holes in the floor of the rooms. The emplacement holes are backfilled with crushed salt or other material and sealed at some later time. Sensitivity studies are presented to show the effect of changing the areal heat load, the canister heat load, the barrier material and thickness, ventilation of the storage room, and adding a second row to the emplacement configuration. The calculated thermal environment is used as input for brine migration calculations. The vapor and gas pressure will gradually attain the lithostatic pressure in a sealed repository. In the unlikely event that an emplacement hole will become sealed in relatively early years, the vapor space pressure was calculated for three scenarios (i.e., no hole closure - no backfill, no hole closure - backfill, and hole closure - no backfill). It was assumed that the gas in the system consisted of air and water vapor in equilibrium with brine. A computer code (REPRESS) was developed assuming that these changes occur slowly (equilibrium conditions). The brine chemical environment is outlined in terms of brine chemistry, corrosion, and compositions. The nuclear radiation environment emphasized in this report is the stored energy that can be released as a result of radiation damage or crystal dislocations within crystal lattices.

  20. Optimizing nuclear waste repository development by implementing experimental data on radiolysis

    SciTech Connect

    Paviet-Hartmann, Patricia; Hartmann, Thomas

    2007-07-01

    In a conceivable scenario of proposed geological salt repositories for nuclear waste within the time frame of 10,000 to 100,000 years being considered for performance assessment, groundwater intrusion leads to inundation of the repository and the formation of chloride-based brines. These brines will be exposed to {alpha}- radiation emitted by released transuranic waste constituents, mainly Pu, U, Am, and Np. In the absence of bromide, {alpha}-radiolysis causes the formation of radiolytic species such as hypochlorite (OCl{sup -}) and hypochlorous acid (HOCl). Natural brines contain at least traces of bromide ions to influence radiation chemical effects in the near-field of the nuclear disposal site. We are presenting new results on the irradiation-induced formation of two bromide species: ClBr{sub 2}{sup -} and Br{sub 3}{sup -} observed at 247 nm and 266 nm by spectrophotometry after irradiating synthetic NaCl based brine solutions, containing 1.13 g of NaBr, by 5.2 MeV He{sup ++} ions by using a 3 MV Tandem accelerator. The measured formation rates as G values (100 eV yields) are G(Br{sub 2}Cl{sup -}) = 3.51*10{sup -3} {+-} 0.04*10{sup -3} molecules per 100 eV, and G(Br{sub 3}{sup -}) = 2.67*10{sup -3} {+-} 0.04.10{sup -3} molecules per 100 eV radiation energy. (authors)

  1. Modelling groundwater contamination above a nuclear waste repository at Gorleben, Germany

    NASA Astrophysics Data System (ADS)

    Schwartz, Michael O.

    2012-05-01

    The candidate repository for high-level nuclear waste in the Gorleben salt dome, Germany, is expected to host 8,550 tonnes of uranium in burnt fuel. It has been proposed that 5,440 waste containers be deposited at a depth of about 800 m. There is 260-280 m of siliciclastic cover sediments above the proposed repository. The potential groundwater contamination in the siliciclastic aquifer is simulated with the TOUGHREACT and TOUGH2-MP codes for a three-dimensional model with 290,435 elements. Two deterministic cases are simulated. The single-phase case considers the transport of radionuclides in the liquid phase only. The two-phase case accounts for hydrogen gas generated by the corrosion of waste containers and release of gaseous C-14. The gas release via a backfilled shaft is assumed to be steady (non-explosive). The simulation period is 2,000,000 years for the single-phase case and 7,000 years for the two-phase case. Only the radioactive dose in the two-phase case is higher than the regulatory limit (0.1 mSv/a).

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

    SciTech Connect

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

    1984-11-01

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

  3. Results of instrument reliability study for high-level nuclear-waste repositories. [Geotechnical parameters

    SciTech Connect

    Rogue, F.; Binnall, E.P.

    1982-10-01

    Reliable instrumentation will be needed to monitor the performance of future high-level waste repository sites. A study has been made to assess instrument reliability at Department of Energy (DOE) waste repository related experiments. Though the study covers a wide variety of instrumentation, this paper concentrates on experiences with geotechnical instrumentation in hostile repository-type environments. Manufacturers have made some changes to improve the reliability of instruments for repositories. This paper reviews the failure modes, rates, and mechanisms, along with manufacturer modifications and recommendations for additional improvements to enhance instrument performance. 4 tables.

  4. Role of natural analogs in performance assessment of nuclear waste repositories

    SciTech Connect

    Sagar, B.; Wittmeyer, G.W.

    1995-09-01

    Mathematical models of the flow of water and transport of radionuclides in porous media will be used to assess the ability of deep geologic repositories to safely contain nuclear waste. These models must, in some sense, be validated to ensure that they adequately describe the physical processes occurring within the repository and its geologic setting. Inasmuch as the spatial and temporal scales over which these models must be applied in performance assessment are very large, validation of these models against laboratory and small-scale field experiments may be considered inadequate. Natural analogs may provide validation data that are representative of physico-chemical processes that occur over spatial and temporal scales as large or larger than those relevant to repository design. The authors discuss the manner in which natural analog data may be used to increase confidence in performance assessment models and conclude that, while these data may be suitable for testing the basic laws governing flow and transport, there is insufficient control of boundary and initial conditions and forcing functions to permit quantitative validation of complex, spatially distributed flow and transport models. The authors also express their opinion that, for collecting adequate data from natural analogs, resources will have to be devoted to them that are much larger than are devoted to them at present.

  5. Overweight truck shipments to nuclear waste repositories: legal, political, administrative and operational considerations

    SciTech Connect

    Not Available

    1986-03-01

    This report, prepared for the Chicago Operations Office and the Office of Civilian Radioactive Waste Management (OCRWM) of the US Department of Energy (DOE), identifies and analyzes legal, political, administrative, and operational issues that could affect an OCRWM decision to develop an overweight truck cask fleet for the commercial nuclear waste repository program. It also provides information required by DOE on vehicle size-and-weight administration and regulation, pertinent to nuclear waste shipments. Current legal-weight truck casks have a payload of one pressurized-water reactor spent fuel element or two boiling-water reactor spent fuel elements (1 PWR/2 BWR). For the requirements of the 1960s and 1970s, casks were designed with massive shielding to accommodate 6-month-old spent fuel; the gross vehicle weight was limited to 73,280 pounds. Spent fuel to be moved in the 1990s will have aged five years or more. Gross vehicle weight limitation for the Interstate highway system has been increased to 80,000 pounds. These changes allow the design of 25-ton legal-weight truck casks with payloads of 2 PWR/5 BWR. These changes may also allow the development of a 40-ton overweight truck cask with a payload of 4 PWR/10 BWR. Such overweight casks will result in significantly fewer highway shipments compared with legal-weight casks, with potential reductions in transport-related repository risks and costs. These advantages must be weighed against a number of institutional issues surrounding such overweight shipments before a substantial commitment is made to develop an overweight truck cask fleet. This report discusses these issues in detail and provides recommended actions to DOE.

  6. Long-Term Environmental Monitoring of an Operating Deep Geologic Nuclear Waste Repository

    SciTech Connect

    Conca, J.; Kirchner, Th.; Monk, J.; Sage, S.

    2008-07-01

    In the present energy dilemma in which we find ourselves, the magnitude of humanity's energy needs requires that we embrace a multitude of various energy sources and applications. Nuclear energy must be a major portion of the distribution. One often-cited strategic hurdle to the commercial production of nuclear energy is the apparent lack of an acceptable nuclear waste repository. This issue has been quietly addressed at the U. S. Department of Energy (DOE) Waste Isolation Pilot Plant (WIPP; see http://www.wipp.energy.gov), the closest population center of significant size being Carlsbad, New Mexico. WIPP has been operating for about nine years, disposing of over 250,000 drum-equivalents of nuclear waste. From the standpoint of addressing operational and environmental risk, as well as public fear, WIPP has had extensive human health and environmental monitoring. The Carlsbad Environmental Monitoring and Research Center is in the Institute for Energy and the Environment, in the College of Engineering at New Mexico State University. Located in Carlsbad, NM, CEMRC has been the independent monitoring facility for the area around WIPP from 1993 to the present, i.e., from six years before disposal operations began to nine years of waste disposal operations (www.cemcr.org). Based on the radiological analyses of monitoring samples completed to date for area residents and site workers, and for selected aerosols, soils, sediments, drinking water and surface waters, there is no evidence of increases in radiological contaminants in the region of WIPP that could be attributed to releases from WIPP. Levels of radiological and non-radiological analytes measured since operations began in 1999 have been within the range of baseline levels measured previously, and are within the ranges measured by other entities at the State and local levels since well before disposal phase operations began in 1999. (authors)

  7. Perceived risk and benefit of nuclear waste repositories: four opinion clusters.

    PubMed

    Seidl, Roman; Moser, Corinne; Stauffacher, Michael; Krütli, Pius

    2013-06-01

    Local public resistance can block the site-selection process, construction, and operation of nuclear waste repositories. Social science has established that the perception of risks and benefits, trust in authorities, and opinion on nuclear energy play important roles in acceptance. In particular, risk and benefit evaluations seem critical for opinion formation. However, risks and benefits have rarely been studied independently and, most often, the focus has been on the two most salient groups of proponents and opponents. The aim of this exploratory study is to examine the often-neglected majority of people holding ambivalent or indifferent opinions. We used cluster analysis to examine the sample (N = 500, mailed survey in German-speaking Switzerland) in terms of patterns of risk and benefit perception. We reveal four significantly different and plausible clusters: one cluster with high-benefit ratings in favor of a repository and one cluster with high-risk ratings opposing it; a third cluster shows ambivalence, with high ratings on both risk and benefit scales and moderate opposition, whereas a fourth cluster seems indifferent, rating risks and benefits only moderately compared to the ambivalent cluster. We conclude that a closer look at the often neglected but considerable number of people with ambivalent or indifferent opinions is necessary. Although the extreme factions of the public will most probably not change their opinion, we do not yet know how the opinion of the ambivalent and indifferent clusters might develop over time.

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

    SciTech Connect

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

    1991-01-01

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

  9. Sub-Seabed Repository for Nuclear Waste - a Strategic Alternative - 13102

    SciTech Connect

    McAllister, Keith R.

    2013-07-01

    It was recognized at the outset of nuclear power generation in the 1950's that the waste products would require isolation away from humans for periods in excess of 10,000 years. After years studying alternatives, the DOE recommended pursuing the development of a SNF/HLW disposal facility within Yucca Mountain in the desert of Nevada. That recommendation became law with passage of the NWPAA, effectively stopping development of other approaches to the waste problem. In the face of political resistance from the state of Nevada, the 2010 decision to withdraw the license application for the geologic repository at Yucca Mountain has delayed further the most mature option for safe, long-term disposal of SNF and HLW. It is time to revisit an alternative option, sub-seabed disposal within the US Exclusive Economic Zone (EEZ), which would permanently sequester waste out of the biosphere, and out of the reach of saboteurs or terrorists. A proposal is made for a full scale pilot project to demonstrate burying radioactive waste in stable, deep ocean sediments. While much of the scientific work on pelagic clays has been done to develop a sub-seabed waste sequestration capability, this proposal introduces technology from non-traditional sources such as riser-less ocean drilling and the Navy's Sound Surveillance System. The political decisions affecting the issue will come down to site selection and a thorough understanding of comparative risks. The sub-seabed sequestration of nuclear waste has the potential to provide a robust solution to a critical problem for this clean and reliable energy source. (authors)

  10. Geochemically Homogeneous Tuffs Host the Potential Nuclear Waste Repository, Yucca Mountain, Nevada

    SciTech Connect

    Z.E. Peterman

    2001-07-13

    In evaluating a geological environment for the disposition of nuclear waste, the composition of the host rock is an important parameter in characterizing the natural system and its role as a barrier to migration of radionuclides. Emplacement drifts in a potential nuclear waste repository at Yucca Mountain, Nevada, would be constructed in the lower phenocryst-poor rhyolitic member ({approx}300 m thick) of the Topopah Spring Tuff, a felsic pyroclastic ash flow. The rhyolitic member, composed largely of microcrystalline quartz and alkali feldspar, contains localized secondary minerals including vapor-phase silica polymorphs and feldspar typically lining lithophysal cavities, and low-temperature calcite and opal in cavities and fractures. Chemical analyses of Topopah Spring Tuff samples from outcrops and from core obtained by surface-based drilling have shown that the phenocryst-poor rhyolite member at Yucca Mountain is remarkably uniform in composition both vertically and laterally. To verify this geochemical homogeneity in samples collected directly from the repository block where emplacement drifts would be constructed, major and trace elements were analyzed for core samples obtained from 20 systematically spaced drill holes in a drift constructed across the repository block. Means and standard deviations of selected oxides and elements in weight percent indicate geochemical uniformity among these samples: SiO{sub 2}, 76.29 {+-} 0.32; Al{sub 2}O{sub 3}, 12.55 {+-} 0.14; FeO, 0.13 {+-} 0.05; Fe{sub 2}O{sub 3}, 0.97 {+-} 0.07; MgO, 0.12 {+-} 0.02; CaO, 0.50 {+-} 0.03; Na{sub 2}O, 3.52 {+-} 0.11; K{sub 2}O, 4.83 {+-} 0.06; TiO{sub 2}, 0.109 {+-} 0.004; ZrO{sub 2}, 0.016 {+-} 0.001; MnO, 0.068 {+-} 0.008; Cl, 0.017 {+-} 0.004; F, 0.038 {+-} 0.008; and CO{sub 2}, 0.011 {+-} 0.003. Means and standard deviations of selected trace elements, in micrograms per gram, also indicate small compositional variability: Ba, 51 {+-} 12; Cs, 4.2 {+-} 0.3; Li, 25 {+-} 9; Pb, 27 {+-} 1

  11. Microstructural and mineralogical characterization of selected shales in support of nuclear waste repository studies

    SciTech Connect

    Lee, S.Y.; Hyder, L.K.; Alley, P.D.

    1988-01-01

    Five shales were examined as part of the Sedimentary Rock Program evaluation of this medium as a potential host for a US civilian nuclear waste repository. The units selected for characterization were the Chattanooga Shale from Fentress County, Tennessee; the Pierre Shale from Gregory County, South Dakota; the Green River Formation from Garfield County, Colorado; and the Nolichucky Shale and Pumpkin Valley Shale from Roane County, Tennessee. The micromorphology and structure of the shales were examined by petrographic, scanning electron, and high-resolution transmission electron microscopy. Chemical and mineralogical compositions were studied through the use of energy-dispersive x-ray, neutron activation, atomic absorption, thermal, and x-ray diffraction analysis techniques. 18 refs., 12 figs., 2 tabs.

  12. Coupled THMC models for bentonite in clay repository for nuclear waste

    NASA Astrophysics Data System (ADS)

    Zheng, L.; Rutqvist, J.; Birkholzer, J. T.; Li, Y.; Anguiano, H. H.

    2015-12-01

    Illitization, the transformation of smectite to illite, could compromise some beneficiary features of an engineered barrier system (EBS) that is composed primarily of bentonite and clay host rock. It is a major determining factor to establish the maximum design temperature of the repositories because it is believed that illitization could be greatly enhanced at temperatures higher than 100 oC and thus significantly lower the sorption and swelling capacity of bentonite and clay rock. However, existing experimental and modeling studies on the occurrence of illitization and related performance impacts are not conclusive, in part because the relevant couplings between the thermal, hydrological, chemical, and mechanical (THMC) processes have not been fully represented in the models. Here we present fully coupled THMC simulations of a generic nuclear waste repository in a clay formation with bentonite-backfilled EBS. Two scenarios were simulated for comparison: a case in which the temperature in the bentonite near the waste canister can reach about 200 oC and a case in which the temperature in the bentonite near the waste canister peaks at about 100 oC. The model simulations demonstrate that illitization is in general more significant at higher temperatures. We also compared the chemical changes and the resulting swelling stress change for two types of bentonite: Kunigel-VI and FEBEX bentonite. Higher temperatures also lead to much higher stress in the near field, caused by thermal pressurization and vapor pressure buildup in the EBS bentonite and clay host rock. Chemical changes lead to a reduction in swelling stress, which is more pronounced for Kunigel-VI bentonite than for FEBEX bentonite.

  13. Sorption of strontium on uranyl peroxide: implications for a high-level nuclear waste repository.

    PubMed

    Sureda, Rosa; Martínez-Lladó, Xavier; Rovira, Miquel; de Pablo, Joan; Casas, Ignasi; Giménez, Javier

    2010-09-15

    Strontium-90 is considered the most important radioactive isotope in the environment and one of the most frequently occurring radionuclides in groundwaters at nuclear facilities. The uranyl peroxide studtite (UO2O2 . 4H2O) has been observed to be formed in spent nuclear fuel leaching experiments and seems to have a relatively high sorption capacity for some radionuclides. In this work, the sorption of strontium onto studtite is studied as a function of time, strontium concentration in solution and pH. The main results obtained are (a) sorption is relatively fast although slower than for cesium; (b) strontium seems to be sorbed via a monolayer coverage of the studtite surface, (c) sorption has a strong dependence on ionic strength, is negligible at acidic pH, and increases at neutral to alkaline pH (almost 100% of the strontium in solution is sorbed above pH 10). These results point to uranium secondary solid phase formation on the spent nuclear fuel as an important mechanism for strontium retention in a high-level nuclear waste repository (HLNW).

  14. MODELING OF THE GROUNDWATER TRANSPORT AROUND A DEEP BOREHOLE NUCLEAR WASTE REPOSITORY

    SciTech Connect

    N. Lubchenko; M. Rodríguez-Buño; E.A. Bates; R. Podgorney; E. Baglietto; J. Buongiorno; M.J. Driscoll

    2015-04-01

    The concept of disposal of high-level nuclear waste in deep boreholes drilled into crystalline bedrock is gaining renewed interest and consideration as a viable mined repository alternative. A large amount of work on conceptual borehole design and preliminary performance assessment has been performed by researchers at MIT, Sandia National Laboratories, SKB (Sweden), and others. Much of this work relied on analytical derivations or, in a few cases, on weakly coupled models of heat, water, and radionuclide transport in the rock. Detailed numerical models are necessary to account for the large heterogeneity of properties (e.g., permeability and salinity vs. depth, diffusion coefficients, etc.) that would be observed at potential borehole disposal sites. A derivation of the FALCON code (Fracturing And Liquid CONvection) was used for the thermal-hydrologic modeling. This code solves the transport equations in porous media in a fully coupled way. The application leverages the flexibility and strengths of the MOOSE framework, developed by Idaho National Laboratory. The current version simulates heat, fluid, and chemical species transport in a fully coupled way allowing the rigorous evaluation of candidate repository site performance. This paper mostly focuses on the modeling of a deep borehole repository under realistic conditions, including modeling of a finite array of boreholes surrounded by undisturbed rock. The decay heat generated by the canisters diffuses into the host rock. Water heating can potentially lead to convection on the scale of thousands of years after the emplacement of the fuel. This convection is tightly coupled to the transport of the dissolved salt, which can suppress convection and reduce the release of the radioactive materials to the aquifer. The purpose of this work has been to evaluate the importance of the borehole array spacing and find the conditions under which convective transport can be ruled out as a radionuclide transport mechanism

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

    SciTech Connect

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

    1986-10-01

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

  16. Bentonite alteration due to thermal-hydro-chemical processes during the early thermal period in a nuclear waste repository

    SciTech Connect

    Xu, T.; Senger, R.; Finsterle, S.

    2011-02-01

    After closure of an underground nuclear waste repository, the decay of radionuclides will raise temperature in the repository, and the bentonite buffer will resaturate by water inflow from the surrounding host rock. The perturbations from these thermal and hydrological processes are expected to dissipate within hundreds to a few thousand years. Here, we investigate coupled thermal-hydro-chemical processes and their effects on the short-term performance of a potential nuclear waste repository located in a clay formation. Using a simplified geometric configuration and abstracted hydraulic parameters of the clayey formation, we examine geochemical processes, coupled with thermo-hydrologic phenomena, and potential changes in porosity near the waste container during the early thermal period. The developed models were used for evaluating the mineral alterations and potential changes in porosity of the buffer, which can affect the repository performance. The results indicate that mineral alteration and associated changes in porosity induced by early thermal and hydrological processes are relatively small and are expected to not significantly affect flow and transport properties. Chlorite precipitation was obtained in all simulation cases. A maximum of one percent volume fraction of chlorite could be formed, whose process may reduce swelling and sorption capacity of bentonite clay, affecting the performance of the repository. llitisation process was not obtained from the present simulations.

  17. Postclosure risks of alternative SRP nuclear waste forms in geologic repositories

    SciTech Connect

    Cheung, H.; Edwards, L.; Harvey, T.; Revelli, M.

    1982-05-01

    The postclosure risk of REFERENCE and ALTERNATIVE waste forms for the defense high-level waste at the Savannah River Plant (SRP) were compared by analyses with a computer code, MISER, written to study the effects of repository features in a probabilistic framework. MISER traces radionuclide flows through a network of stream tubes from the repository to risk-sensitive points. Uncertainties in waste form, package properties, and geotechnical data are accounted for with Monte Carlo techniques. Our results show: (1) for generic layered-salt and basalt repositories, the difference in performance between the two waste forms is insignificant; (2) where the doses are sensitive to uncertainties in leaching rates, the doses are orders of magnitude below background; (3) disruptive events contribute only slightly to the risk of a layered-salt repository; (4) simple design alterations have strong effects on near field doses; (5) great care should be exercised in selecting the location at which repository risks are to be measured, calculated, or regulated.

  18. SUMO, System performance assessment for a high-level nuclear waste repository: Mathematical models

    SciTech Connect

    Eslinger, P.W.; Miley, T.B.; Engel, D.W.; Chamberlain, P.J. II

    1992-09-01

    Following completion of the preliminary risk assessment of the potential Yucca Mountain Site by Pacific Northwest Laboratory (PNL) in 1988, the Office of Civilian Radioactive Waste Management (OCRWM) of the US Department of Energy (DOE) requested the Performance Assessment Scientific Support (PASS) Program at PNL to develop an integrated system model and computer code that provides performance and risk assessment analysis capabilities for a potential high-level nuclear waste repository. The system model that has been developed addresses the cumulative radionuclide release criteria established by the US Environmental Protection Agency (EPA) and estimates population risks in terms of dose to humans. The system model embodied in the SUMO (System Unsaturated Model) code will also allow benchmarking of other models being developed for the Yucca Mountain Project. The system model has three natural divisions: (1) source term, (2) far-field transport, and (3) dose to humans. This document gives a detailed description of the mathematics of each of these three divisions. Each of the governing equations employed is based on modeling assumptions that are widely accepted within the scientific community.

  19. Geotechnical support and topical studies for nuclear waste geologic repositories: Annual report, fiscal year 1987

    SciTech Connect

    Not Available

    1988-01-01

    This multidisciplinary project was initiated in fiscal year 1986. It comprises 11 reports in two major interrelated tasks: The technical assistance part of the project includes reviewing the progress of the major projects in the DOE Office of Civilian Radioactive waste Management (OCRWM) Program and advising the Engineering and Geotechnology Division on significant technical issues facing each project; analyzing geotechnical data, reports, tests, surveys and plans for the different projects; reviewing and commenting on major technical reports and other program documents such as Site Characterization Plans (SCP) and Study Plans; and providing scientific and technical input at technical meetings. The topical studies activity comprises studies on scientific and technical ions and issues of significance to in-situ testing, test analysis methods, and site characterization of nuclear waste geologic repositories. The subjects of study were selected based on discussions with DOE staff. One minor topic is a preliminary consideration and planning exercise for postclosure monitoring studies. The major task, with subtasks involving various geoscience disciplines, is a study of the mechanical, hydraulic, geophysical and geochemical properties of fractures in geologic rock masses.

  20. A Prototype Performance Assessment Model for Generic Deep Borehole Repository for High-Level Nuclear Waste - 12132

    SciTech Connect

    Lee, Joon H.; Arnold, Bill W.; Swift, Peter N.; Hadgu, Teklu; Freeze, Geoff; Wang, Yifeng

    2012-07-01

    A deep borehole repository is one of the four geologic disposal system options currently under study by the U.S. DOE to support the development of a long-term strategy for geologic disposal of commercial used nuclear fuel (UNF) and high-level radioactive waste (HLW). The immediate goal of the generic deep borehole repository study is to develop the necessary modeling tools to evaluate and improve the understanding of the repository system response and processes relevant to long-term disposal of UNF and HLW in a deep borehole. A prototype performance assessment model for a generic deep borehole repository has been developed using the approach for a mined geological repository. The preliminary results from the simplified deep borehole generic repository performance assessment indicate that soluble, non-sorbing (or weakly sorbing) fission product radionuclides, such as I-129, Se-79 and Cl-36, are the likely major dose contributors, and that the annual radiation doses to hypothetical future humans associated with those releases may be extremely small. While much work needs to be done to validate the model assumptions and parameters, these preliminary results highlight the importance of a robust seal design in assuring long-term isolation, and suggest that deep boreholes may be a viable alternative to mined repositories for disposal of both HLW and UNF. (authors)

  1. Seismic Response of a Deep Underground Geologic Repository for Nuclear Waste at the Waste Isolation Pilot Plant in New Mexico

    SciTech Connect

    Sanchez, P.E.

    1998-11-02

    The Waste Isolation Pilot Plant (WIPP) is a deep underground nuclear waste repository certified by the U.S. Environmental Protection Agency ,(EPA) to store transuranic defense-related waste contaminated by small amounts of radioactive materials. Located at a depth of about 655 meters below the surface, the facility is sited in southeastern New Mexico, about 40 Department of Energy underground facilities, waste disposal. kilometers east of the city of Carlsbad, New Mexico. The U.S. (DOE) managed the design and construction of the surface and and remains responsible for operation and closure following The managing and operating contractor for the DOE at the WIPP, Westinghouse Electric Corporation, maintains two rechmiant seismic monitoring systems located at the surface and in the underground. This report discusses two earthquakes detected by the seismic monitoring system, one a duratior magnitude 5.0 (Md) event located approximately 60 km east-southeast of the facility, and another a body-wave magnitude 5.6 (rob) event that occurred approximately 260 kilometers to the south-southeast.

  2. Evaluation of microbial activity for long-term performance assessments of deep geologic nuclear waste repositories.

    SciTech Connect

    Francis, Arokiasamy J.; Wang, Yifeng

    2005-06-01

    Microorganisms are ubiquitous in subsurface environments and play a major role in the biogeochemical recycling of various elements. In this paper, we have developed a general approach for a systematic evaluation of microbial impact on the long-term performance of the repository. We have demonstrated that data on microbial population alone are not sufficient for the evaluation of microbial impact on repository performance and a sensible approach for such evaluation must be based on the consideration of environmental constraints on microbial reaction pathways. We have applied our approach to both the Yucca Mountain (YM) repository and the Waste Isolation Pilot Plant (WIPP). We have demonstrated that the effect of microbial activity on the near-field chemistry in the Yucca Mountain repository is negligible because of limited nutrient supply and harsh environmental conditions created by waste emplacement. Whereas for the WIPP, we have shown that, due to the presence of a large quantity of organic materials and nutrients in the wastes, a significant microbial activity can potentially be stimulated and its impact on repository performance can be evaluated with carefully designed incubation experiments coupled with performance assessment calculations. The impact of microbial gas generation on disposal room chemistry in the WIPP can be mitigated by introducing MgO as a backfill material.

  3. Thermal calculations pertaining to a proposed Yucca Mountain nuclear waste repository

    SciTech Connect

    Johnson, G.L.; Montan, D.N.

    1990-02-01

    In support to the Yucca Mountain Project waste package and repository design efforts, LLNL conducted heat-transfer modeling of the volcanic tuff in the repository. The analyses quantify: the thermal response of a finite size, uniformly loaded repository where each panel of emplacement drifts contains the same type of heat source the response given a realistic waste stream inventory to show the effect of inter-panel variations; and the intra-panel response for various realistic distributions of sources within the panel. The calculations, using the PLUS family of computer codes, are based on a linear superposition, in time and in space, of the analytic solution of individual, constant output point sources located in an infinite, isotropic, and homogeneous medium with constant thermal properties. 8 refs., 22 figs., 3 tabs.

  4. Using focused hard X-rays for investigations of nuclear waste repository analogs

    NASA Astrophysics Data System (ADS)

    Denecke, M. A.

    2009-04-01

    Micro-focused synchrotron radiation techniques to investigate determinant processes in actinide element transport in geological media are becoming an increasingly used tool in nuclear waste disposal research. There are a number of reasons for this but primarily they are driven by the need to characterize radionuclide speciation localized in components of heterogeneous natural systems. The advantage of using X-rays is that in situ investigations are possible, due to elimination of a vacuum requirement, no need for invasive sample preparation, and the high penetration capability of X-rays. The ultimate goal of such studies is to advance development of reliable predictive models for radionuclide transport processes at varying spatial and temporal scales, with a reliable estimate of uncertainty. This information is necessary for designing safe nuclear disposal concepts by assessing potential hazards associated with any radioactive contamination release. Examples using µ-XRF, µ-XAFS, and µ-XRD, partly in confocal geometry, to characterize what are referred to as natural analogs, in this case clayey sediments rich in uranium [1-4], will be presented. Natural analogs are considered to mimic repository geochemical and geological conditions on a geological time scale and knowledge gained from their study can be used to span the long time scales in a top down approach for predicting repository radiological safety. [1] M.A. Denecke, W. De Nolf, K. Janssens, B. Brendebach, A. Rothkirch, G. Falkenberg, U. Noseck, Spectrochim. Acta B 63, 484-492 (2008). [2] M.A. Denecke, A. Somogyi, K. Janssens, R. Simon, K. Dardenne, U. Noseck, Microscopy Microanal. 13(3), 165-172 (2007). [3] M.A. Denecke, K. Janssens, K. Proost, J. Rothe, U. Noseck, Environ. Sci. Technol. 39(7), 2049-2058 (2005). [4] P. Michel, M.A. Denecke, T. Schäfer, B. Brendebach, K. Dardenne, J. Rothe, T. Vitova, F. Huber, K. Rickers, M. Elie, G. Buckau, Proceedings to the 5th Nuclear Energy Agency (NEA) Workshop on

  5. Supplemental Performance Analyses for the Potential High-Level Nuclear Waste Repository at Yucca Mountain

    SciTech Connect

    Sevougian, S. D.; McNeish, J. A.; Coppersmith, K.; Jenni, K. E.; Rickertsen, L. D.; Swift, P. N.; Wilson, M. L.

    2002-02-26

    The U.S. Department of Energy (DOE) is considering the possible recommendation of a site at Yucca Mountain, Nevada, for the potential development of a geologic repository for the disposal of high-level radioactive waste and spent nuclear fuel. To facilitate public review and comment, in May 2001 the DOE released the Yucca Mountain Science and Engineering Report (S&ER) (1), which presents technical information supporting the consideration of the possible site recommendation. The report summarizes the results of more than 20 years of scientific and engineering studies. Based on internal reviews of the S&ER and its key supporting references, the Total System Performance Assessment for the Site Recommendation (TSPA-SR) (2) and the Analysis Model Reports and Process Model Reports cited therein, the DOE has recently identified and performed several types of analyses to supplement the treatment of uncertainty in support of the consideration of a possible site recommendation. The results of these new analyses are summarized in the two-volume report entitled FY01 Supplemental Science and Performance Analysis (SSPA) (3,4). The information in this report is intended to supplement, not supplant, the information contained in the S&ER. The DOE recognizes that important uncertainties will always remain in any assessment of the performance of a potential repository over thousands of years (1). One part of the DOE approach to recognizing and managing these uncertainties is a commitment to continued testing and analysis and to the continued evaluation of the technical basis supporting the possible recommendation of the site, such as the analysis contained in the SSPA. The goals of the work described here are to provide insights into the implications of newly quantified uncertainties, updated science, and evaluations of lower operating temperatures on the performance of a potential Yucca Mountain repository and to increase confidence in the results of the TSPA described in the S

  6. Geology and hydrogeology of the proposed nuclear waste repository at Yucca Mountain, Nevada and the surrounding area

    SciTech Connect

    Mattson, S.R.; Broxton, D.E.; Crowe, B.M.; Buono, A.; Orkild, P.P.

    1989-07-01

    In late 1987 Congress issued an amendment to the Nuclear Waste Policy Act of 1982 which directed the characterization of Yucca Mountain, Nevada as the only remaining potential site for the Nation`s first underground high-level radioactive waste repository. The evaluation of a potential underground repository is guided and regulated by policy established by the Department of Energy (DOE), Nuclear Regulatory Commission (NRC), Environmental Protection Agency (EPA), Department of Transportation (DOT), and the US Congress. The Yucca Mountain Project is the responsibility of the DOE. The purpose of this field trip is to introduce the present state of geologic and hydrologic knowledge concerning this site. This report describes the field trip. 108 refs., 6 figs., 1 tab.

  7. Review of geochemical measurement techniques for a nuclear waste repository in bedded salt

    SciTech Connect

    Knauss, K.G.; Steinborn, T.L.

    1980-05-22

    A broad, general review is presented of geochemical measurement techniques that can provide data necessary for site selection and repository effectiveness assessment for a radioactive waste repository in bedded salt. The available measurement techniques are organized according to the parameter measured. The list of geochemical parameters include all those measurable geochemical properties of a sample whole values determine the geochemical characteristics or behavior of the system. For each technique, remarks are made pertaining to the operating principles of the measurement instrument and the purpose for which the technique is used. Attention is drawn to areas where further research and development are needed.

  8. Results From an International Simulation Study on Couples Thermal, Hydrological, and Mechanical (THM) Processes Near Geological Nuclear Waste Repositories

    SciTech Connect

    J. Rutqvist; D. Barr; J.T. Birkholzer; M. Chijimatsu; O. Kolditz; Q. Liu; Y. Oda; W. Wang; C. Zhang

    2006-08-02

    As part of the ongoing international DECOVALEX project, four research teams used five different models to simulate coupled thermal, hydrological, and mechanical (THM) processes near waste emplacement drifts of geological nuclear waste repositories. The simulations were conducted for two generic repository types, one with open and the other with back-filled repository drifts, under higher and lower postclosure temperatures, respectively. In the completed first model inception phase of the project, a good agreement was achieved between the research teams in calculating THM responses for both repository types, although some disagreement in hydrological responses is currently being resolved. In particular, good agreement in the basic thermal-mechanical responses was achieved for both repository types, even though some teams used relatively simplified thermal-elastic heat-conduction models that neglected complex near-field thermal-hydrological processes. The good agreement between the complex and simplified process models indicates that the basic thermal-mechanical responses can be predicted with a relatively high confidence level.

  9. Multiscale Thermohydrologic Model Analyses of Heterogeneity and Thermal-Loading Factors for a Proposed Nuclear Waste Repository

    SciTech Connect

    Lee, K; Buscheck, T A; Gansemer, J; Glascoe, L G; Sun, Y

    2004-01-06

    The MultiScale ThermoHydrologic Model is used to predict thermal-hydrologic conditions in emplacement drifts and the adjoining host-rock throughout a proposed nuclear waste repository. The presented modeling effort simulates a lower temperature operation mode with a different panel loading than the repository currently being considered for the Yucca Mountain license application. Simulations address the influence of repository-scale thermal-conductivity heterogeneity and the influence of pre-closure operational factors on thermal-loading conditions. MSTHM can accommodate a complex repository layout, a development that, along with other improvements, enables more rigorous analyses of preclosure operational factors. Differences in MSTHM output occurring with these new capabilities are noted for a new sequential waste-package loading technique compared to a standard simultaneous loading technique. Alternative approaches to modeling repository-scale thermal-conductivity heterogeneity in the host-rock units are investigated, and study incorporating geostatistically-varied host-rock thermal conductivity is discussed.

  10. Nuclear waste

    SciTech Connect

    Not Available

    1991-09-01

    Radioactive waste is mounting at U.S. nuclear power plants at a rate of more than 2,000 metric tons a year. Pursuant to statute and anticipating that a geologic repository would be available in 1998, the Department of Energy (DOE) entered into disposal contracts with nuclear utilities. Now, however, DOE does not expect the repository to be ready before 2010. For this reason, DOE does not want to develop a facility for monitored retrievable storage (MRS) by 1998. This book is concerned about how best to store the waste until a repository is available, congressional requesters asked GAO to review the alternatives of continued storage at utilities' reactor sites or transferring waste to an MRS facility, GAO assessed the likelihood of an MRSA facility operating by 1998, legal implications if DOE is not able to take delivery of wastes in 1998, propriety of using the Nuclear Waste Fund-from which DOE's waste program costs are paid-to pay utilities for on-site storage capacity added after 1998, ability of utilities to store their waste on-site until a repository is operating, and relative costs and safety of the two storage alternatives.

  11. Microbial impacts on the geochemistry evolution in a nuclear waste repository -Laboratory experiment of microbially mediated redox changes-

    NASA Astrophysics Data System (ADS)

    Nagaoka, T.

    2010-12-01

    It is important to investigate geochemical evolution around nuclear waste repositories, because geochemical conditions could affect radionuclide migration. Therefore, a laboratory jar experiment was conducted with subsurface sediments, in order to assess the response of the geochemical and microbial communities toward redox processes. The redox process was induced by exposure to air and discontinuation to sediment suspension, which simulated the process occurring during operation of nuclear waste repositories, i.e., tunnel excavation, transport of waste containers, and final backfilling. During the experiments, redox potential, dissolved oxygen, and pH in the suspension were measured, and the concentrations of dissolved ions concentration (e.g., NO3-, SO42- and organic acid), HCl-extractable iron, and also head space gasses (e.g., CO2, CH4) in the jar were analyzed. Moreover, microbial DNA was extracted from the suspension, and PCR-DGGE analysis was performed to analyze the response of microbial communities toward the geochemical changes. As a results, after discontinuation of air exposure with lactate amendment, redox potentials decreased from ca. +300 mV to -430 m V (vs. Ag/AgCl), and the sequential terminal electron-accepting process (TEAPs) was observed with the reactions of aerobic respiration, nitrate reduction, iron reduction, sulfate reduction, and methanogenesis. The related species of the microbes along with TEAPs, e.g., Pseudomonas sp. for nitrate reduction and Desulfovibrio sp. for sulfate reduction, was also detected. These results indicated that the microbial activities would affect the geochemical changes in nuclear repositories.

  12. Radioactive waste isolation in salt: special advisory report on the status of the Office of Nuclear Waste Isolation's plans for repository performance assessment

    SciTech Connect

    Ditmars, J.D.; Walbridge, E.W.; Rote, D.M.; Harrison, W.; Herzenberg, C.L.

    1983-10-01

    Repository performance assessment is analysis that identifies events and processes that might affect a repository system for isolation of radioactive waste, examines their effects on barriers to waste migration, and estimates the probabilities of their occurrence and their consequences. In 1983 Battelle Memorial Institute's Office of Nuclear Waste Isolation (ONWI) prepared two plans - one for performance assessment for a waste repository in salt and one for verification and validation of performance assessment technology. At the request of the US Department of Energy's Salt Repository Project Office (SRPO), Argonne National Laboratory reviewed those plans and prepared this report to advise SRPO of specific areas where ONWI's plans for performance assessment might be improved. This report presents a framework for repository performance assessment that clearly identifies the relationships among the disposal problems, the processes underlying the problems, the tools for assessment (computer codes), and the data. In particular, the relationships among important processes and 26 model codes available to ONWI are indicated. A common suggestion for computer code verification and validation is the need for specific and unambiguous documentation of the results of performance assessment activities. A major portion of this report consists of status summaries of 27 model codes indicated as potentially useful by ONWI. The code summaries focus on three main areas: (1) the code's purpose, capabilities, and limitations; (2) status of the elements of documentation and review essential for code verification and validation; and (3) proposed application of the code for performance assessment of salt repository systems. 15 references, 6 figures, 4 tables.

  13. US nuclear repository in jeopardy

    NASA Astrophysics Data System (ADS)

    Gwynne, Peter

    2009-04-01

    Physicists have expressed uneasiness about the future of nuclear-waste storage in the US after President Barack Obama's administration proposed slashing funds for a long-planned repository at Yucca Mountain in Nevada. If approved by Congress, the cuts seem likely to spell the death knell of the project, which has been in the works since 1987 and has so far cost the government 9.5bn.

  14. Materials Degradation Issues in the U.S. High-Level Nuclear Waste Repository

    SciTech Connect

    K.G. Mon; F. Hua

    2005-04-12

    This paper reviews the state-of-the-art understanding of the degradation processes by the Yucca Mountain Project (YMP) with focus on interaction between the in-drift environmental conditions and long-term materials degradation of waste packages and drip shields within the repository system during the first 10,000-years after repository closure. This paper provides an overview of the degradation of the waste packages and drip shields in the repository after permanent closure of the facility. The degradation modes discussed in this paper include aging and phase instability, dry oxidation, general and localized corrosion, stress corrosion cracking, and hydrogen induced cracking of Alloy 22 and titanium alloys. The effects of microbial activity and radiation on the degradation of Alloy 22 and titanium alloys are also discussed. Further, for titanium alloys, the effects of fluorides, bromides, and galvanic coupling to less noble metals are considered. It is concluded that the materials and design adopted will provide sufficient safety margins for at least 10,000-years after repository closure.

  15. Social impacts of hazardous and nuclear facilities and events: Implications for Nevada and the Yucca Mountain high-level nuclear waste repository; [Final report

    SciTech Connect

    Freudenburg, W.R.; Carter, L.F.; Willard, W.; Lodwick, D.G.; Hardert, R.A.; Levine, A.G.; Kroll-Smith, S.; Couch, S.R.; Edelstein, M.R.

    1992-05-01

    Social impacts of a nuclear waste repository are described. Various case studies are cited such as Rocky Flats Plant, the Feed Materials Production Center, and Love Canal. The social impacts of toxic contamination, mitigating environmental stigma and loss of trust are also discussed.

  16. The Use of Basalt, Basalt Fibers and Modified Graphite for Nuclear Waste Repository - 12150

    SciTech Connect

    Gulik, V.I.; Biland, A.B.

    2012-07-01

    New materials enhancing the isolation of radioactive waste and spent nuclear fuel are continuously being developed.. Our research suggests that basalt-based materials, including basalt roving chopped basalt fiber strands, basalt composite rebar and materials based on modified graphite, could be used for enhancing radioactive waste isolation during the storage and disposal phases and maintaining it during a significant portion of the post-closure phase. The basalt vitrification process of nuclear waste is a viable alternative to glass vitrification. Basalt roving, chopped basalt fiber strands and basalt composite rebars can significantly increase the strength and safety characteristics of nuclear waste and spent nuclear fuel storages. Materials based on MG are optimal waterproofing materials for nuclear waste containers. (authors)

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

    SciTech Connect

    Bill Carey; Gordon Keating; Peter C. Lichtner

    1999-08-01

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

  18. Micron-Scale MIC of Alloy 22 After Long Term Incubation in Saturated Nuclear Waste Repository Microcosms

    SciTech Connect

    Martin, S; Horn, J; Carrillo, C

    2003-10-29

    The effects of potential microbiologically influenced corrosion (MIC) on candidate packaging materials for nuclear waste containment are being assessed. Coupons of Alloy 22, the outer barrier candidate for waste packaging, were exposed to a simulated, saturated repository environment consisting of crushed rock from the repository site and a continual flow of simulated groundwater for periods up to five years. Coupons were incubated with YM tuff under both sterile and non-sterile conditions. Surfacial analysis of the biotically-incubated coupons show development of both submicron-sized pinholes and pores; these features were not present on either sterile or untreated control coupons. Quantification of these effects will help define the overall contribution of MIC to the integrity of the containment system over a period of 10,000 years.

  19. BIODOSE: a code for predicting the dose to man from radionuclides released from underground nuclear waste repositories

    SciTech Connect

    Bonner, N.A.; Ng, Y.C.

    1980-03-01

    The BIODOSE computer program simulates the environmental transport of radionuclides released to surface water and predicts the resulting dosage to humans. This report describes the program and discusses its use in the evaluation of nuclear waste repositories. The methods used to estimate dose are examined critically, and the most important parameters in each stage of the calculations are identified as an aid in planning for measurements in the field. Dose predictions from releases of nuclear waste to a large northwestern river (the baseline river) are presented to point out the nuclides, compartments and pathways that contribute most to the hazard as a function of waste storage time. Predictions for five other water systems are presented to identify the most important system parameters that determine the concentrations of individual nuclides in compartments and the resultant dose. The uncertainties in the biological parameters for dose prediction are identified, and changes in current values are suggested. Various ways of reporting dose estimates for radiological safety assessments are discussed. Additional work needed to improve the dose predictions from BIODOSE and specific areas and steps to improve our capabilities to assess the environmental transport of nuclides released from nuclear waste repositories and the resultant dose to man are suggested.

  20. Perceived risk, stigma, and potential economic impacts of a high-level nuclear waste repository in Nevada

    SciTech Connect

    Slovic, P.; Layman, M.; Kraus, N.N.; Chalmers, J.; Gesel, G.; Flynn, J.

    1989-07-01

    This paper describes a program of research designed to assess the potential impacts of a high-level nuclear waste repository at Yucca Mountain, Nevada, upon tourism, retirement and job-related migration, and business development in Las Vegas and the state. Adverse economic impacts may be expected to result from two related social processes. One has to do with perceptions of risk and socially amplified reactions to ``unfortunate events`` associated with the repository (major and minor accidents, discoveries of radiation releases, evidence of mismanagement, attempts to sabotage or disrupt the facility, etc.). The second process that may trigger significant adverse impacts is that of stigmatization. The conceptual underpinnings of risk perception, social amplification, and stigmatization are discussed in this paper and empirical data are presented to demonstrate how nuclear images associated with Las Vegas and the State of Nevada might trigger adverse effects on tourism, migration, and business development.

  1. Non-equilibrium fluid flow around the Yucca Mountain Nuclear Waste Repository

    SciTech Connect

    Reis, J.C.

    1995-08-01

    The results of this study are consistent with the G-Tunnel test results, which indicated no water bank forming above the dry zone, and differ from the simulation results based on the equivalent continuum model (ECM), which indicated a water bank may form above the dry zone. The reason that the simulation studies predict the creation of a water bank is that the ECM assumes capillary equilibrium between the fractures and matrix. This study quantified the non-equilibrium fluid flow between the fractures and matrix and has shown that water entering the fractures above the dry zone will drain away from the repository before capillary equilibrium could be created. Thus, the ECM models are inappropriate for many studies of water transport around the proposed Yucca Mountain repository. It is noted that the authors of the ECM studies recognized this limitation and recommended that the more difficult non-equilibrium studies be conducted. It is concluded that a significant water bank above the repository from the redistribution of water from nuclear decay heating is unlikely. Thus, the integrity of the repository is not expected to-be threatened by rewetting of the formation from a water bank.

  2. Science Is Important, but Politics Drives the Siting of Nuclear Waste Repositories

    NASA Astrophysics Data System (ADS)

    Shaw, George H.

    2014-02-01

    In 1982, I worked on the Nuclear Waste Policy Act as an AGU Congressional Science Fellow tasked with assisting a member of the House Energy and Commerce Committee. When I recently read the suggestion that clay-rich strata (shales) could be a viable medium for high-level nuclear waste (HLW) disposal [Neuzil, 2013], I could not help but remember the insights I gained more than 30 years ago from my time on the Hill.

  3. Prediction of Coupled Thermal, Hydrological and Chemical Processes at the Proposed Yucca Mountain Nuclear Waste Repository: An Integrated Approach

    SciTech Connect

    N. Spycher; E. Sonnenthal; T. Kneafsey; P. Dobson

    2003-10-17

    An integrated modeling approach was developed to investigate long-term coupled thermal, hydrological, and chemical (THC) processes that could take place around nuclear waste emplacement tunnels (drifts). The approach involves the development of process models, followed by numerical implementation and validation against field and laboratory experiments before conducting long-term predictive simulations. An outcome of this work was the refinement and validation of an existing reactive transport numerical code for applications specific to the geologic storage of nuclear waste. The model was applied to the case of the proposed high-level nuclear waste repository at Yucca Mountain, Nevada, to evaluate the chemistry of waters potentially seeping into drifts and the effect of water-rock interaction on long-term hydrological behavior around the repository. At liquid saturations significantly larger than residual, no extreme pH or salinity values were predicted. Mineral precipitation around drifts consists mainly of silica with minor calcite, trace zeolites and clays. The effect of mineral precipitation on flow depends largely on initial fracture porosity, and results in negligible to significant diversion of percolation around the drift. Further analyses of model uncertainty are under way to improve confidence in model results.

  4. AN EVALUATION OF HYDROGEN INDUCED CRACKING SUSCEPTIBILITY OF TITANIUM ALLOYS IN US HIGH-LEVEL NUCLEAR WASTE REPOSITORY ENVIRONMENTS

    SciTech Connect

    G. De; K. Mon; G. Gordon; D. Shoesmith; F. Hua

    2006-02-21

    This paper evaluates hydrogen-induced cracking (HIC) susceptibility of titanium alloys in environments anticipated in the Yucca Mountain nuclear waste repository with particular emphasis on the. effect of the oxide passive film on the hydrogen absorption process of titanium alloys being evaluated. The titanium alloys considered in this review include Ti 2, 5 , 7, 9, 11, 12, 16, 17, 18, 24 and 29. In general, the concentration of hydrogen in a titanium alloy can increase due to absorption of atomic hydrogen produced from passive general corrosion of that alloy or galvanic coupling of it to a less noble metal. It is concluded that under the exposure conditions anticipated in the Yucca Mountain repository, the HIC of titanium drip shield will not occur because there will not be sufficient hydrogen in the metal even after 10,000 years of emplacement. Due to the conservatisms adopted in the current evaluation, this assessment is considered very conservative.

  5. A comparative simulation study of coupled THM processes and their effect on fractured rock permeability around nuclear waste repositories

    SciTech Connect

    Rutqvist, Jonny; Barr, Deborah; Birkholzer, Jens T.; Fujisaki, Kiyoshi; Kolditz, Olf; Liu, Quan-Shen; Fujita, tomoo; Wang, Wenqing; Zhang, Cheng-Yuan

    2008-10-23

    This paper presents an international, multiple-code, simulation study of coupled thermal, hydrological, and mechanical (THM) processes and their effect on permeability and fluid flow in fractured rock around heated underground nuclear waste emplacement drifts. Simulations were conducted considering two types of repository settings: (a) open emplacement drifts in relatively shallow unsaturated volcanic rock, and (b) backfilled emplacement drifts in deeper saturated crystalline rock. The results showed that for the two assumed repository settings, the dominant mechanism of changes in rock permeability was thermal-mechanically-induced closure (reduced aperture) of vertical fractures, caused by thermal stress resulting from repository-wide heating of the rock mass. The magnitude of thermal-mechanically-induced changes in permeability was more substantial in the case of an emplacement drift located in a relatively shallow, low-stress environment where the rock is more compliant, allowing more substantial fracture closure during thermal stressing. However, in both of the assumed repository settings in this study, the thermal-mechanically-induced changes in permeability caused relatively small changes in the flow field, with most changes occurring in the vicinity of the emplacement drifts.

  6. Some Materials Degradation Issues in the U.S. High-Level Nuclear Waste Repository Study (The Yucca Mountain Project)

    SciTech Connect

    F. Hua; P. Pasupathi; N. Brown; K. Mon

    2005-09-19

    The safe disposal of radioactive waste requires that the waste be isolated from the environment until radioactive decay has reduced its toxicity to innocuous levels for plants, animals, and humans. All of the countries currently studying the options for disposing of high-level nuclear waste (HLW) have selected deep geologic formations to be the primary barrier for accomplishing this isolation. In U.S.A., the Nuclear Waste Policy Act of 1982 (as amended in 1987) designated Yucca Mountain in Nevada as the potential site to be characterized for high-level nuclear waste (HLW) disposal. Long-term containment of waste and subsequent slow release of radionuclides into the geosphere will rely on a system of natural and engineered barriers including a robust waste containment design. The waste package design consists of a highly corrosion resistant Ni-based Alloy 22 cylindrical barrier surrounding a Type 316 stainless steel inner structural vessel. The waste package is covered by a mailbox-shaped drip shield composed primarily of Ti Grade 7 with Ti Grade 24 structural support members. The U.S. Yucca Mountain Project has been studying and modeling the degradation issues of the relevant materials for some 20 years. This paper reviews the state-of-the-art understanding of the degradation processes based on the past 20 years studies on Yucca Mountain Project (YMP) materials degradation issues with focus on interaction between the in-drift environmental conditions and long-term materials degradation of waste packages and drip shields within the repository system during the 10,000 years regulatory period. This paper provides an overview of the current understanding of the likely degradation behavior of the waste package and drip shield in the repository after the permanent closure of the facility. The degradation scenario discussed in this paper include aging and phase instability, dry oxidation, general and localized corrosion, stress corrosion cracking and hydrogen induced

  7. Nuclear waste

    SciTech Connect

    Not Available

    1988-05-01

    This paper discusses how, as part of the Department of Energy's implementation of the Nuclear Waste Policy Act of 1982, DOE is required to investigate a site at Yucca Mountain, Nevada and, if it determines that the site is suitable, recommend to the President its selection for a nuclear waste repository. The Nuclear Regulatory Commission, in considering development of the plan, issued five objections, one of which is DOE's failure to recognize the range of alternative conceptual models of the Yucca Mountain site that can be supported by the limited existing technical data. At the end of the quarter DOE directed its project offices in Washington and Texas to begin orderly phase-out of all site-specific repository activities. Costs for this phase-out are $53 million for the Deaf Smith site and $85 million for the Hanford site.

  8. Can Sisyphus succeed? Getting U.S. high-level nuclear waste into a geological repository.

    PubMed

    North, D Warner

    2013-01-01

    The U.S. government has the obligation of managing the high-level radioactive waste from its defense activities and also, under existing law, from civilian nuclear power generation. This obligation is not being met. The January 2012 Final Report from the Blue Ribbon Commission on America's Nuclear Future provides commendable guidance but little that is new. The author, who served on the federal Nuclear Waste Technical Review Board from 1989 to 1994 and subsequently on the Board on Radioactive Waste Management of the National Research Council from 1994 to 1999, provides a perspective both on the Commission's recommendations and a potential path toward progress in meeting the federal obligation. By analogy to Sisyphus of Greek mythology, our nation needs to find a way to roll the rock to the top of the hill and have it stay there, rather than continuing to roll back down again.

  9. Can Sisyphus succeed? Getting U.S. high-level nuclear waste into a geological repository.

    PubMed

    North, D Warner

    2013-01-01

    The U.S. government has the obligation of managing the high-level radioactive waste from its defense activities and also, under existing law, from civilian nuclear power generation. This obligation is not being met. The January 2012 Final Report from the Blue Ribbon Commission on America's Nuclear Future provides commendable guidance but little that is new. The author, who served on the federal Nuclear Waste Technical Review Board from 1989 to 1994 and subsequently on the Board on Radioactive Waste Management of the National Research Council from 1994 to 1999, provides a perspective both on the Commission's recommendations and a potential path toward progress in meeting the federal obligation. By analogy to Sisyphus of Greek mythology, our nation needs to find a way to roll the rock to the top of the hill and have it stay there, rather than continuing to roll back down again. PMID:23311528

  10. Perceived risk, stigma, and potential economic impacts of a high-level nuclear waste repository in Nevada

    SciTech Connect

    Slovic, P.; Layman, M.; Kraus, N.; Flynn, J.; Chalmers, J.; Gesell, G.

    1991-12-01

    This study investigates the potential impacts of the proposed nuclear waste repository at Yucca Mountain, Nevada, upon tourism, retirement and job-related migration, and business development in Las Vegas and the state. Adverse impacts may be expected to result from perceptions of risk, stigmatization, and socially amplified reactions to `unfortunate events` associated with the repository (major and minor accidents, discoveries of radiation releases, evidence of mismanagement, attempts to sabotage or disrupt the facility, etc.). The conceptual underpinnings of risk perception, stigmatization, and social amplification are discussed and empirical data are presented to demonstrate how nuclear images associated with Las Vegas and the State of Nevada might trigger adverse economic effects. The possibility that intense negative imagery associated with the repository may cause significant harm to Nevada`s economy can no longer be ignored by serious attempts to assess the risks and impacts of this unique facility. The behavioral processes described here appear relevant as well to the social impact assessment of any proposed facility that produces, uses, transports, or disposes of hazardous materials.

  11. Perceived risk, stigma, and potential economic impacts of a high-level nuclear waste repository in Nevada.

    PubMed

    Slovic, P; Layman, M; Kraus, N; Flynn, J; Chalmers, J; Gesell, G

    1991-12-01

    This study investigates the potential impacts of the proposed nuclear waste repository at Yucca Mountain, Nevada, upon tourism, retirement and job-related migration, and business development in Las Vegas and the state. Adverse impacts may be expected to result from perceptions of risk, stigmatization, and socially amplified reactions to "unfortunate events" associated with the repository (major and minor accidents, discoveries of radiation releases, evidence of mismanagement, attempts to sabotage or disrupt the facility, etc.). The conceptual underpinnings of risk perception, stigmatization, and social amplification are discussed and empirical data are presented to demonstrate how nuclear images associated with Las Vegas and the State of Nevada might trigger adverse economic effects. The possibility that intense negative imagery associated with the repository may cause significant harm to Nevada's economy can no longer be ignored by serious attempts to assess the risks and impacts of this unique facility. The behavioral processes described here appear relevant as well to the social impact assessment of any proposed facility that produces, uses, transports, or disposes of hazardous materials.

  12. Physico-chemical interactions at the concrete-bitumen interface of nuclear waste repositories

    NASA Astrophysics Data System (ADS)

    Bertron, A.; Ranaivomanana, H.; Jacquemet, N.; Erable, B.; Sablayrolles, C.; Escadeillas, G.; Albrecht, A.

    2013-07-01

    This study investigates the fate of nitrate and organic acids at the bitumenconcrete-steel interface within a repository storage cell for long-lived, intermediatelevel, radioactive wastes. The interface was simulated by a multiphase system in which cementitious matrices (CEM V-paste specimens) were exposed to bitumen model leachates consisting of nitrates and acetic acid with and without oxalic acid, chemical compounds likely to be released by bitumen. Leaching experiments were conducted with daily renewal of the solutions in order to accelerate reactions. C-steel chips, simulating the presence of steel in the repository, were added in the systems for some experiments. The concentrations of anions (acetate, oxalate, nitrate, and nitrite) and cations (calcium, potassium, ammonium) and the pH were monitored over time. Mineralogical changes of the cementitious matrices were analysed by XRD. The results confirmed the stability of nitrates in the absence of steel, whereas, reduction of nitrates was observed in the presence of steel (production of NH4+). The action of acetic acid on the cementitious matrix was similar to that of ordinary leaching; no specific interaction was detected between acetate and cementitious cations. The reaction of oxalic acid with the cementitious phases led to the precipitation of calcium oxalate salts in the outer layer of the matrix. The concentration of oxalate was reduced by 65% inside the leaching medium.

  13. What comes to mind when you hear the words nuclear waste repository '': A study of 10,000 images

    SciTech Connect

    Slovic, P.; Layman, M.; Flynn, J.H. )

    1990-09-01

    Attempts by the federal government and the nuclear industry to develop sites for disposal of high-level and low-level radioactive wastes have been stymied by public and political opposition. The record of strenuous protest against nuclear waste repositories, as well as the findings of numerous public opinion surveys, make it clear that public opposition is widespread and deeply felt. It is also clear that there is an immense gap between the perceptions of the pubic and the views of technical experts and nuclear-industry officials. Given the seriousness of nuclear waste as a public issue, it is surprising that there have been only a few attempts to understand the deeper meaning of nuclear fears and opposition to nuclear waste disposal sites, and to provide some insight into the nature and pervasiveness of people's concerns. One step toward a deeper understanding would be to define the origins of these concerns, the emotions and images that underlie them, and their tractability or stability over time. In the present study, the authors recorded 10,000 word-association images from more than 3,300 respondents to four surveys during the period between April, 1988 and January 1, 1990. Each of the 10,000 images was assigned to one of thirteen general or superordinate categories, which expressed the dominant theme of the response. All but one superordinate categories contained subordinate categories. All in all there were 92 distinct categories. The two dominant superordinate categories, (1) negative consequences and (2) negative concepts accounted for more than 56% of the total number of images. Many of the smaller categories and subcategories were also quite negative in tone. The five leading subordinate categories, dangerous toxic, death sickness, environmental damage, bad, and scary, accounted for more than 42% of the total number of images. 27 refs., 6 tabs.

  14. Selection of candidate container materials for the conceptual waste package design for a potential high level nuclear waste repository at Yucca Mountain

    SciTech Connect

    Van Konynenburg, R.A.; Halsey, W.G.; McCright, R.D.; Clarke, W.L. Jr.; Gdowski, G.E.

    1993-02-01

    Preliminary selection criteria have been developed, peer-reviewed, and applied to a field of 41 candidate materials to choose three alloys for further consideration during the advanced conceptual design phase of waste package development for a potential high level nuclear waste repository at Yucca Mountain, Nevada. These three alloys are titanium grade 12, Alloy C-4, and Alloy 825. These selections are specific to the particular conceptual design outlined in the Site Characterization Plan. Other design concepts that may be considered in the advanced conceptual design phase may favor other materials choices.

  15. Nye County Nuclear Waste Repository Project Office independent scientific investigations program annual report, May 1997--April 1998

    SciTech Connect

    1998-07-01

    This annual summary report, prepared by the Nye County Nuclear Waste Repository Project Office (NWRPO), summarizes the activities that were performed during the period from May 1, 1997 to April 30, 1998. These activities were conducted in support of the Independent Scientific Investigation Program (ISIP) of Nye County at the Yucca Mountain Site (YMS). The Nye County NWRPO is responsible for protecting the health and safety of the Nye County residents. NWRPO`s on-site representative is responsible for designing and implementing the Independent Scientific Investigation Program (ISIP). Major objectives of the ISIP include: Investigating key issues related to conceptual design and performance of the repository that can have major impact on human health, safety, and the environment; identifying areas not being addressed adequately by the Department of Energy (DOE). Nye County has identified several key scientific issues of concern that may affect repository design and performance which were not being adequately addressed by DOE. Nye County has been conducting its own independent study to evaluate the significance of these issues. This report summarizes the results of monitoring from two boreholes and the Exploratory Studies Facility (ESF) tunnel that have been instrumented by Nye County since March and April of 1995. The preliminary data and interpretations presented in this report do not constitute and should not be considered as the official position of Nye County. The ISIP presently includes borehole and tunnel instrumentation, monitoring, data analysis, and numerical modeling activities to address the concerns of Nye County.

  16. Effect of transport-pathway simplifications on projected releases of radionuclides from a nuclear waste repository (Sweden)

    NASA Astrophysics Data System (ADS)

    Selroos, Jan-Olof; Painter, Scott L.

    2012-12-01

    The Swedish Nuclear Fuel and Waste Management Company has recently submitted an application for a license to construct a final repository for spent nuclear fuel, at approximately 500 m depth in crystalline bedrock. Migration pathways through the geosphere barrier are geometrically complex, with segments in fractured rock, deformation zones, backfilled tunnels, and near-surface soils. Several simplifications of these complex migration pathways were used in the assessments of repository performance that supported the license application. Specifically, in the geosphere transport calculations, radionuclide transport in soils and tunnels was neglected, and deformation zones were assumed to have transport characteristics of fractured rock. The effects of these simplifications on the projected performance of the geosphere barrier system are addressed. Geosphere performance is shown to be sensitive to how transport characteristics of deformation zones are conceptualized and incorporated into the model. Incorporation of advective groundwater travel time within backfilled tunnels reduces radiological dose from non-sorbing radionuclides such as I-129, while sorption in near-surface soils reduces radiological doses from sorbing radionuclides such as Ra-226. These results help quantify the degree to which geosphere performance was pessimistically assessed, and provide some guidance on how future studies to reduce uncertainty in geosphere performance may be focused.

  17. A strategy for describing the biosphere at candidate sites for repositories of nuclear waste: linking ecosystem and landscape modeling.

    PubMed

    Lindborg, Tobias; Lindborg, Regina; Löfgren, Anders; Söderbäck, Björn; Bradshaw, Clare; Kautsky, Ulrik

    2006-12-01

    To provide information necessary for a license application for a deep repository for spent nuclear fuel, the Swedish Nuclear Fuel and Waste Management Co. has started site investigations at two sites in Sweden. In this paper, we present a strategy to integrate site-specific ecosystem data into spatially explicit models needed for safety assessment studies and the environmental impact assessment. The site-specific description of ecosystems is developed by building discipline-specific models from primary data and by identifying interactions and stocks and flows of matter among functional units at the sites. The conceptual model is a helpful initial tool for defining properties needed to quantify system processes, which may reveal new interfaces between disciplines, providing a variety of new opportunities to enhance the understanding of the linkages between ecosystem characteristics and the functional properties of landscapes. This type of integrated ecosystem-landscape characterization model has an important role in forming the implementation of a safety assessment for a deep repository.

  18. Current Status and Potential Impacts Regarding the Proposed Development of a Rail Line to the Yucca Mountain Nuclear Waste Repository

    SciTech Connect

    Lanthrum, G.; Gunnerson, J.

    2008-07-01

    This paper provides a description of the current status regarding the proposed development of a rail line to the Yucca Mountain Nuclear Waste Repository in Nye County, Southern Nevada, which includes potential impacts analyzed during the National Environmental Policy Act (NEPA) process, and the subsequent creation of an Environmental Impact Statement (EIS) for the rail line. Potential impacts are addressed within the context of impacts to natural and human environmental resources found within the geographic area of the proposed federal project. Potential impacts to these resources have been fully analyzed in the Rail Alignment Draft EIS (DEIS). This paper includes a summary of the potential impacts analyzed in the DEIS. Examples of potential impacts include land use conflicts, air quality, water use, and impacts to biological and cultural resources, among others. In conclusion: Based on its obligations under the NWPA and its decision to select the mostly rail scenario for the transportation of spent nuclear fuel and high-level radioactive waste, DOE needs to ship these materials by rail in Nevada to a repository at Yucca Mountain. DOE prepared the Rail Alignment EIS to provide the background, data, information, and analyses to help decision makers and the public understand the potential environmental impacts that could result from constructing and operating a railroad for shipment of spent nuclear fuel, high-level radioactive waste, and other materials from an existing rail line in Nevada to a repository at Yucca Mountain. This railroad would consist of a rail line, railroad operations support facilities, and other related infrastructure. DOE will use the Rail Alignment EIS to decide whether to construct and operate the proposed railroad, and if so, to: - Select a rail alignment (Caliente rail alignment or Mina rail alignment) in which to construct the railroad; - Select the common segments and alternative segments within either a Caliente rail alignment or a Mina

  19. Site characterization plan conceptual design report for a high-level nuclear waste repository in salt, vertical emplacement mode: Volume 1

    SciTech Connect

    Not Available

    1987-12-01

    This Conceptual Design Report describes the conceptual design of a high-level nuclear waste repository in salt at a proposed site in Deaf Smith County, Texas. Waste receipt, processing, packing, and other surface facility operations are described. Operations in the shafts underground are described, including waste hoisting, transfer, and vertical emplacement. This report specifically addresses the vertical emplacement mode, the reference design for the repository. Waste retrieval capability is described. The report includes a description of the layout of the surface, shafts, and underground. Major equipment items are identified. The report includes plans for decommissioning and sealing of the facility. The report discusses how the repository will satisfy performance objectives. Chapters are included on basis for design, design analyses, and data requirements for completion of future design efforts. 105 figs., 52 tabs.

  20. Recommended new criteria for the selection of nuclear waste repository sites in Columbia River basalt and US Gulf Coast domed salt

    SciTech Connect

    Steinborn, T.L.; Wagoner, J.L.; Qualheim, B.; Fitts, C.R.; Stetkar, R.E.; Turnbull, R.W.

    1980-06-16

    Screening criteria and specifications are recommended to aid in the evaluation of sites proposed for nuclear waste disposal in basalt and domed salt. The recommended new criteria proposed in this report are intended to supplement existing repository-related criteria for nuclear waste disposal. The existing criteria are contained in 10 CFR 60 sections which define siting criteria of the Nuclear Regulatory Commission (NRC), and ONWI 33(2) which defines siting criteria of the Office of Nuclear Waste Isolation (ONWI) for the Department of Energy. The specifications are conditions or parameter values that the authors recommend be applied in site acceptance evaluations. The siting concerns covered in this report include repository depth, host rock extent, seismic setting, structural and tectonic conditions, groundwater and rock geochemistry, volcanism, surface and subsurface hydrology, and socioeconomic issues, such as natural resources, land use, and population distribution.

  1. Performance assessment of radioactive waste repositories.

    PubMed

    Campbell, J E; Cranwell, R M

    1988-03-18

    The current plans for permanent disposal of radioactive waste call for its emplacement in deep underground repositories mined from geologically stable rock formations. The U.S. Nuclear Regulatory Commission and U.S. Environmental Protection Agency have established regulations setting repository performance standards for periods of up to 10,000 years after disposal. Compliance with these regulations will be based on a performance assessment that includes (i) identification and evaluation of the likelihood of all significant processes and events that could affect a repository, (ii) examination of the effects of these processes and events on the performance of a repository, and (iii) estimation of the releases of radionuclides, including the associated uncertainties, caused by these processes and events. These estimates are incorporated into a probability distribution function showing the likelihood of exceeding radionuclide release limits specified by regulations. PMID:3279510

  2. Death Valley Lower Carbonate Aquifer Monitoring Program Wells Down gradient of the Proposed Yucca Mountain Nuclear Waste Repository

    SciTech Connect

    Inyo County

    2006-07-26

    Inyo County has participated in oversight activities associated with the Yucca Mountain Nuclear Waste Repository since 1987. The overall goal of these studies are the evaluation of far-field issues related to potential transport, by ground water, or radionuclides into Inyo County, including Death Valley, and the evaluation of a connection between the Lower Carbonate Aquifer (LCA) and the biosphere. Our oversight and completed Cooperative Agreement research, and a number of other investigators research indicate that there is groundwater flow between the alluvial and carbonate aquifers both at Yucca Mountain and in Inyo County. In addition to the potential of radionuclide transport through the LCA, Czarnecki (1997), with the US Geological Survey, research indicate potential radionuclide transport through the shallower Tertiary-age aquifer materials with ultimate discharge into the Franklin Lake Playa in Inyo County. The specific purpose of this Cooperative Agreement drilling program was to acquire geological, subsurface geology, and hydrologic data to: (1) establish the existence of inter-basin flow between the Amargosa Basin and Death Valley Basin; (2) characterize groundwater flow paths in the LCA through Southern Funeral Mountain Range, and (3) Evaluation the hydraulic connection between the Yucca Mountain repository and the major springs in Death Valley through the LCA.

  3. Nye County nuclear waste repository project office independent scientific investigations program. Summary annual report, May 1996--April 1997

    SciTech Connect

    1997-05-01

    This annual summary report, prepared by Multimedia Environmental Technology, Inc. (MET) on behalf of Nye County Nuclear Waste Project Office, summarizes the activities that were performed during the period from May 1, 1996 to April 30, 1997. These activities were conducted in support of the Independent Scientific Investigation Program (ISIP) of Nye County at the Yucca Mountain Site (YMS). The Nye County NWRPO is responsible for protecting the health and safety of the Nye County residents. NWRPO`s on-site representative is responsible for designing and implementing the Independent Scientific Investigation Program (ISIP). Major objectives of the ISIP include: (1) Investigating key issues related to conceptual design and performance of the repository that can have major impact on human health, safety, and the environment. (2) Identifying areas not being addressed adequately by DOE Nye County has identified several key scientific issues of concern that may affect repository design and performance which were not being adequately addressed by DOE. Nye County has been conducting its own independent study to evaluate the significance of these issues.

  4. Closure development for high-level nuclear waste containers for the tuff repository; Phase 1, Final report

    SciTech Connect

    Robitz, E.S. Jr.; McAninch, M.D. Jr.; Edmonds, D.P. |

    1990-09-01

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

  5. AEGIS technology demonstration for a nuclear waste repository in basalt. Assessment of effectiveness of geologic isolation systems

    SciTech Connect

    Dove, F.H.; Cole, C.R.; Foley, M.G.

    1982-09-01

    A technology demonstration of current performance assessment techniques as applied to a nuclear waste repository in the Columbia Plateau Basalts was conducted. Hypothetical repository coordinates were selected for an actual geographical setting on the Hanford Reservation in the state of Washington. Published hydrologic and geologic data used in the analyses were gathered in 1979 or earlier. The following report documents the technology demonstration in basalt. Available information has been used to establish the data base and initial hydrologic and geologic interpretations for this site-specific application. A simplified diagram of the AEGIS analyses is shown. Because an understanding of the dynamics of ground-water flow is essential to the development of release scenarios and consequence analyses, a key step in the demonstration is the systems characterization contained in the conceptual model. Regional and local ground-water movement patterns have been defined with the aid of hydrologic computer models. Hypothetical release scenarios have been developed and evaluated by a process involving expert opinion and a Geologic Simulation Model for basalt. (The Geologic Simulation Model can also be used to forecast future boundary conditions for the hydrologic simulation.) Chemical reactivity of the basalt with ground water will influence the leaching and transport of radionuclides; solubility equilibria based on available data are estimated with geochemical models. After the radionuclide concentrations are mathematically introduced into the ground-water movement patterns, waste movement patterns are outlined over elapsed time. Contaminant transport results are summarized for significant radionuclides that are hypothetically released to the accessible environment and to the biosphere.

  6. Study of thermo-hydro-mechanical processes at a potential site of an Indian nuclear waste repository

    NASA Astrophysics Data System (ADS)

    Maheshwar, Sachin; Verma, A. K.; Singh, T. N.; Bajpai, R. K.

    2015-12-01

    A detailed scientific study is required for the disposal of high-level radioactive wastes because they generate extremely high heat during their half-life period. Although, several methods have been proposed for the disposal of nuclear wastes, deep underground repository is considered to be a suitable option. In this paper, field investigation has been done near to Bhima basin of peninsular India. Detailed fracture analysis near the borehole shows very prominent maxima of fractures striking N55∘E coinciding with the trace of master basement cover metasediment fault. Physico-mechanical properties of rocks have been determined in the laboratory. The host rock chosen is granite and engineered barrier near the canister is proposed to be clay. A thermo-hydro-mechanical (THM) analysis has been done to study the effect of heat on deformations, stresses and pore-pressure variation in granite and clay barriers. For this purpose, finite difference method has been used. Suitable rheological models have been used to model elastic canister and elasto-plastic engineered barrier and host rock. It has been found that both temperature and stresses at any point in the rockmass is below the design criteria which are 100∘C for temperature and 0.2 for damage number.

  7. Radioactive waste isolation in salt: peer review of the Office of Nuclear Waste Isolation's reports on preferred repository sites within the Palo Duro Basin, Texas

    SciTech Connect

    Fenster, D.; Edgar, D.; Gonzales, S.; Domenico, P.; Harrison, W.; Engelder, T.; Tisue, M.

    1984-04-01

    Documents are being submitted to the Salt Repository Project Office (SRPO) of the US Department of Energy (DOE) by Battelle Memorial Institute's Office of Nuclear Waste Isolation (ONWI) to satisfy milestones of the Salt Repository Project of the Civilian Radioactive Waste Management Program. Some of these documents are being reviewed by multidisciplinary groups of peers to ensure DOE of their adequacy and credibility. Adequacy of documents refers to their ability to meet the standards of the US Nuclear Regulatory Commission, as enunciated in 10 CFR 60, and the requirements of the National Environmental Policy Act and the Nuclear Waste Policy Act of 1982. Credibility of documents refers to the validity of the assumptions, methods, and conclusions, as well as to the completeness of coverage. This report summarizes Argonne's review of ONWI's two-volume draft report entitled Identification of Preferred Sites within the Palo Duro Basin: Vol. 1 - Palo Duro Location A, and Vol. 2 - Palo Duro Location B, dated January 1984. Argonne was requested by DOE to review these documents on January 17 and 24, 1984 (see App. A). The review procedure involved obtaining written comments on the reports from three members of Argonne's core peer review staff and three extramural experts in related research areas. The peer review panel met at Argonne on February 6, 1984, and reviewer comments were integrated into this report by the review session chairman, with the assistance of Argonne's core peer review staff. All of the peer review panelists concurred in the way in which their comments were represented in this report (see App. B). A letter report and a draft of this report were sent to SRPO on February 10, 1984, and April 17, 1984, respectively. 5 references.

  8. Experimental investigation of hydrous pyrolysis of diesel fuel and the effect of pyrolysis products on performance of the candidate nuclear waste repository at Yucca Mountain, Nevada

    SciTech Connect

    Jackson, K.J.; Carroll, S.A.

    1994-01-01

    It is thought that a significant amount of diesel fuel and other hydrocarbon-rich phases may remain inside the candidate nuclear waste repository at Yucca Mountain after construction and subsequent emplacement of radioactive waste. Although the proposed repository horizon is above the water table, the remnant hydrocarbon phases may react with hydrothermal solutions generated by high temperature conditions that will prevail for a period of time in the repository. The preliminary experimental results of this study show that diesel fuel hydrous pyrolysis is minimal at 200{degrees}C and 70 bars. The composition of the diesel fuel remained constant throughout the experiment and the concentration of carboxylic acids in the aqueous phases was only slightly above the detection limit (1-2 ppm) of the analytical technique.

  9. The use of a high-FeO olivine rock as a redox buffer in a nuclear waste repository.

    PubMed

    Giménez, J; Rovira, M; Clarens, F; Casas, I; Duro, L; Grivé, M; Bruno, J; de Pablo, J

    2006-02-01

    Due to the higher stability of the spent nuclear fuel (mainly composed of UO2) under reducing conditions, and in order to enhance the retention/retardation of some key radionuclides, the olivine rock from the Lovasjärvi intrusion has been proposed as a potential redox-active backfill-additive in deep high-level nuclear waste (HLNW) repositories. In this work, two different approaches have been undertaken in order to establish the redox buffer capacity of olivine rock: (1) The capacity of the rock to respond to changes in pH or pe has been demonstrated and the final (pH, pe) coordinates agree with the control exerted by the system Fe(II)/Fe(III). (2) The rate of consumption of oxygen has been determined at different pH values. These rates are higher than the ones reported in the literature for other solids, what would point to the possibility of using this rock as an additive to the backfill material in a HLNW.

  10. INDIVIDUAL DOSIMETRY IN DISPOSAL REPOSITORY OF HEAT-GENERATING NUCLEAR WASTE.

    PubMed

    Pang, Bo; Saurí Suárez, Héctor; Becker, Frank

    2016-09-01

    Certain working scenarios in a disposal facility of heat-generating nuclear waste might lead to an enhanced level of radiation exposure for workers in such facilities. Hence, a realistic estimation of the personal dose during individual working scenarios is desired. In this study, the general-purpose Monte Carlo N-Particle code MCNP6 (Pelowitz, D. B. (ed). MCNP6 user manual LA-CP-13-00634, Rev. 0 (2013)) was applied to simulate a representative radiation field in a disposal facility. A tool to estimate the personal dose was then proposed by taking into account the influence of individual motion sequences during working scenarios. As basis for this approach, a movable whole-body phantom was developed to describe individual body gestures of the workers during motion sequences. In this study, the proposed method was applied to the German concept of geological disposal in rock salt. The feasibility of the proposed approach was demonstrated with an example of working scenario in an emplacement drift of a rock salt mine.

  11. INDIVIDUAL DOSIMETRY IN DISPOSAL REPOSITORY OF HEAT-GENERATING NUCLEAR WASTE.

    PubMed

    Pang, Bo; Saurí Suárez, Héctor; Becker, Frank

    2016-09-01

    Certain working scenarios in a disposal facility of heat-generating nuclear waste might lead to an enhanced level of radiation exposure for workers in such facilities. Hence, a realistic estimation of the personal dose during individual working scenarios is desired. In this study, the general-purpose Monte Carlo N-Particle code MCNP6 (Pelowitz, D. B. (ed). MCNP6 user manual LA-CP-13-00634, Rev. 0 (2013)) was applied to simulate a representative radiation field in a disposal facility. A tool to estimate the personal dose was then proposed by taking into account the influence of individual motion sequences during working scenarios. As basis for this approach, a movable whole-body phantom was developed to describe individual body gestures of the workers during motion sequences. In this study, the proposed method was applied to the German concept of geological disposal in rock salt. The feasibility of the proposed approach was demonstrated with an example of working scenario in an emplacement drift of a rock salt mine. PMID:27150513

  12. A compound power-law model for volcanic eruptions: Implications for risk assessment of volcanism at the proposed nuclear waste repository at Yucca Mountain, Nevada

    SciTech Connect

    Ho, Chih-Hsiang

    1994-10-17

    Much of the ongoing debate on the use of nuclear power plants in U.S.A. centers on the safe disposal of the radioactive waste. Congress, aware of the importance of the waste issue, passed the Nuclear Waste Policy Act of 1982, requiring the federal government to develop a geologic repository for the permanent disposal of high level radioactive wastes from civilian nuclear power plants. The Department of Energy (DOE) established the Office of Civilian Radioactive Waste Management (OCRWM) in 1983 to identify potential sites. When OCRWM had selected three potential sites to study, Congress enacted the Nuclear Waste Policy Amendments Act of 1987, which directed the DOE to characterize only one of those sites, Yucca Mountain, in southern Nevada. For a site to be acceptable, theses studies must demonstrate that the site could comply with regulations and guidelines established by the federal agencies that will be responsible for licensing, regulating, and managing the waste facility. Advocates and critics disagree on the significance and interpretation of critical geological features which bear on the safety and suitability of Yucca Mountain as a site for the construction of a high-level radioactive waste repository. Recent volcanism in the vicinity of Yucca Mountain is readily recognized as an important factor in determining future public and environmental safety because of the possibility of direct disruption of a repository site by volcanism. In particular, basaltic volcanism is regarded as direct and unequivocal evidence of deep-seated geologic instability. In this paper, statistical analysis of volcanic hazard assessment at the Yucca Mountain site is discussed, taking into account some significant geological factors raised by experts. Three types of models are considered in the data analysis. The first model assumes that both past and future volcanic activities follow a homogeneous Poisson process (HPP).

  13. A Review Corrosion of TI Grade 7 and Other TI Alloys in Nuclear Waste Repository Environments

    SciTech Connect

    F. Hua; K. Mon; P. Pasupathi; G. Gordon

    2004-05-11

    Titanium alloy degradation modes are reviewed in relation to their performance in repository environments. General corrosion, localized corrosion, stress corrosion cracking, hydrogen induced cracking, microbially influenced corrosion, and radiation-assisted corrosion of Ti alloys are considered. With respect to the Ti Grade 7 drip shields selected for emplacement in the repository at Yucca Mountain, general corrosion, hydrogen induced cracking, and radiation-assisted corrosion will not lead to failure within the 10,000 year regulatory period; stress corrosion cracking (in the absence of disruptive events) is of no consequence to barrier performance; and localized corrosion and microbially influenced corrosion are not expected to occur. To facilitate the discussion, Ti Grades 2, 5, 7, 9, 11, 12, 16, 17, 18, and 24 are included in this review.

  14. Environmental and health impacts of February 14, 2014 radiation release from the nation's only deep geologic nuclear waste repository.

    PubMed

    Thakur, P; Lemons, B G; Ballard, S; Hardy, R

    2015-08-01

    The environmental impact of the February 14, 2014 radiation release from the nation's only deep geologic nuclear waste repository, the Waste Isolation Pilot Plant (WIPP) was assessed using monitoring data from an independent monitoring program conducted by the Carlsbad Environmental Monitoring & Research Center (CEMRC). After almost 15 years of safe and efficient operations, the WIPP had one of its waste drums rupture underground resulting in the release of moderate levels of radioactivity into the underground air. A small amount of radioactivity also escaped to the surface through the ventilation system and was detected above ground. It was the first unambiguous release from the WIPP repository. The dominant radionuclides released were americium and plutonium, in a ratio that matches the content of the breached drum. The accelerated air monitoring campaign, which began following the accident, indicates that releases were low and localized, and no radiation-related health effects among local workers or the public would be expected. The highest activity detected was 115.2 μBq/m(3) for (241)Am and 10.2 μBq/m(3) for (239+240)Pu at a sampling station located 91 m away from the underground air exhaust point and 81.4 μBq/m(3) of (241)Am and 5.8 μBq/m(3) of (239+240)Pu at a monitoring station located approximately one kilometer northwest of the WIPP facility. CEMRC's recent monitoring data show that the concentration levels of these radionuclides have returned to normal background levels and in many instances, are not even detectable, demonstrating no long-term environmental impacts of the recent radiation release event at the WIPP. This article presents an evaluation of almost one year of environmental monitoring data that informed the public that the levels of radiation that got out to the environment were very low and did not, and will not harm anyone or have any long-term environmental consequence. In terms of radiological risk at or in the vicinity of the

  15. Environmental and health impacts of February 14, 2014 radiation release from the nation's only deep geologic nuclear waste repository.

    PubMed

    Thakur, P; Lemons, B G; Ballard, S; Hardy, R

    2015-08-01

    The environmental impact of the February 14, 2014 radiation release from the nation's only deep geologic nuclear waste repository, the Waste Isolation Pilot Plant (WIPP) was assessed using monitoring data from an independent monitoring program conducted by the Carlsbad Environmental Monitoring & Research Center (CEMRC). After almost 15 years of safe and efficient operations, the WIPP had one of its waste drums rupture underground resulting in the release of moderate levels of radioactivity into the underground air. A small amount of radioactivity also escaped to the surface through the ventilation system and was detected above ground. It was the first unambiguous release from the WIPP repository. The dominant radionuclides released were americium and plutonium, in a ratio that matches the content of the breached drum. The accelerated air monitoring campaign, which began following the accident, indicates that releases were low and localized, and no radiation-related health effects among local workers or the public would be expected. The highest activity detected was 115.2 μBq/m(3) for (241)Am and 10.2 μBq/m(3) for (239+240)Pu at a sampling station located 91 m away from the underground air exhaust point and 81.4 μBq/m(3) of (241)Am and 5.8 μBq/m(3) of (239+240)Pu at a monitoring station located approximately one kilometer northwest of the WIPP facility. CEMRC's recent monitoring data show that the concentration levels of these radionuclides have returned to normal background levels and in many instances, are not even detectable, demonstrating no long-term environmental impacts of the recent radiation release event at the WIPP. This article presents an evaluation of almost one year of environmental monitoring data that informed the public that the levels of radiation that got out to the environment were very low and did not, and will not harm anyone or have any long-term environmental consequence. In terms of radiological risk at or in the vicinity of the

  16. Final Environmental Impact Statement for a Geologic Repository for the Disposal of Spent Nuclear Fuel and High-Level Radioactive Waste at Yucca Mountain, Nye County, Nevada

    SciTech Connect

    N /A

    2002-10-25

    The purpose of this environmental impact statement (EIS) is to provide information on potential environmental impacts that could result from a Proposed Action to construct, operate and monitor, and eventually close a geologic repository for the disposal of spent nuclear fuel and high-level radioactive waste at the Yucca Mountain site in Nye County, Nevada. The EIS also provides information on potential environmental impacts from an alternative referred to as the No-Action Alternative, under which there would be no development of a geologic repository at Yucca Mountain.

  17. Characteristics of potential repository wastes

    SciTech Connect

    Notz, K.J.

    1989-01-01

    The Office of Civilian Radioactive Waste Management (OCRWM) is responsible for the spent fuels and other wastes that will be disposed of in a geologic repository. The two major sources of these materials are commercial light-water reactor (LWR) spent fuel and immobilized high-level waste (HLW). Other wastes that may require long-term isolation include non-LWR spent fuels and miscellaneous sources such as activated metals. Detailed characterizations are required for all of these potential repository wastes. These characterizations include physical, chemical, and radiological properties. The latter must take into account decay as a function of time. This information has been extracted from primary data sources, evaluated, and assembled in a Characteristics Data Base which provides data in four formats: hard copy standard reports, menu-driven personal computer (PC) data bases, program-level PC data bases, and mainframe computer files. The Characteristics Data Base provides a standard set of self-consistent data to the various areas of responsibility including systems integration and waste stream analysis, storage, transportation, and geologic disposal. The data will be used for design studies, evaluation of alternatives, and system optimization by OCRWM and supporting contractors. 7 refs., 5 figs., 7 tabs.

  18. Images of a place and vacation preferences: Implications of the 1989 surveys for assessing the economic impacts of a nuclear waste repository in Nevada

    SciTech Connect

    Slovic, P.; Layman, M.; Flynn, J.H.

    1990-11-01

    In July, 1989 the authors produced a report titled Perceived Risk, Stigma, and Potential Economic Impacts of a High-Level Nuclear-Waste Repository in Nevada (Slovic et al., 1989). That report described a program of research designed to assess the potential impacts of a high-level nuclear waste repository at Yucca Mountain, Nevada upon tourism, retirement and job-related migration, and business development in Las Vegas and the state. It was concluded that adverse economic impacts potentially may result from two related social processes. Specifically, the study by Slovic et al. employed analyses of imagery in order to overcome concerns about the validity of direct questions regarding the influence of a nuclear-waste repository at Yucca Mountain upon a person`s future behaviors. During the latter months of 1989, data were collected in three major telephone surveys, designed to achieve the following objectives: (1) to replicate the results from the Phoenix, Arizona, surveys using samples from other populations that contribute to tourism, migration, and development in Nevada; (2) to retest the original Phoenix respondents to determine the stability of their images across an 18-month time period and to determine whether their vacation choices subsequent to the first survey were predictable from the images they produced in that original survey; (3) to elicit additional word-association images for the stimulus underground nuclear waste repository in order to determine whether the extreme negative images generated by the Phoenix respondents would occur with other samples of respondents; and (4) to develop and test a new method for imagery elicitation, based upon a rating technique rather than on word associations. 2 refs., 8 figs., 13 tabs.

  19. Results from an International Simulation Study on Coupled Thermal,Hydrological, and Mechanical (THM) Processes near Geological NuclearWaste Repositories

    SciTech Connect

    Rutqvist, Jonny; Rutqvist, J.; Barr, D.; Birkholzer, J.T.; Chijimatsu, M.; Kolditz, O.; Liu, Q.-S; Oda, Y.; Wang, W.; Zhang, C.-Y.

    2007-10-23

    As part of the ongoing international DECOVALEX project, four research teams used five different models to simulate coupled thermal, hydrological, and mechanical (THM) processes near waste emplacement drifts of geological nuclear waste repositories. The simulations were conducted for two generic repository types, one with open and the other with back-filled repository drifts, under higher and lower postclosure temperatures, respectively. In the completed first model inception phase of the project, a good agreement was achieved between the research teams in calculating THM responses for both repository types, although some disagreement in hydrological responses is currently being resolved. In particular, good agreement in the basic thermal-mechanical responses was achieved for both repository types, even though some teams used relatively simplified thermal-elastic heat-conduction models that neglected complex near-field thermal-hydrological processes. The good agreement between the complex and simplified process models indicates that the basic thermal-mechanical responses can be predicted with a relatively high confidence level.

  20. Mineralogical characterization of selected shales in support of nuclear waste repository studies: Progress report

    SciTech Connect

    Lee, S.Y.; Hyder, L.K.; Alley, P.D.

    1987-12-01

    Because baseline characterization of shale mineralogy is critical to the interpretation of results from experiments on radionuclide retardation, groundwater-shale interactions, and physicochemical characteristics, a protocol for quantitative mineralogical analyses has been developed by integrating geochemical and instrumental techniques for the investigation of properties related to repository performance. Thermal analyses were used to estimate total organic matter and carbonate mineral contents. Scanning electron microscope backscattering and elemental mapping of polished sectors and particle-size distribution data were used to estimate the amounts of quartz plus feldspar and pyrite in the shales. X-ray diffraction, neutron activation, and size-distribution data were utilized to estimate phyllosilicate mineral contents. High-resolution transmission electron microscopy was used to identify clay mineral components.

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

    SciTech Connect

    Kim, Kunsoo; Gao, Hang

    1996-04-01

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

  2. Reliability of instrumentation in a simulated nuclear-waste repository environment

    SciTech Connect

    Patrick, W.C.; Rector, N.L.

    1983-06-01

    In light of the observed performance of the geotechnical instrumentation deployed on the Spent Fuel Test-Climax (SFT-C), the following conclusions and recommendations are offered. Further research is required to fully understand the observed failures of linear potentiometers utilized in sealed or partially ventilated extensometer head assemblies. Based on our field observations, we recommend deploying Schaevitz LVDTs or proximeters as extensometer transducers where a sealed head assembly is required. The user must be cognizant of the potential drift and thermal instabilities of these units, however. The first-generation wire extensometers and fracture monitors developed for this test are an accurate, reliable means for measuring convergence and discrete joint motion, respectively. The improved hermetically sealed vibrating-wire stressmeters function reliably. Calibration of the gauge remains difficult and further work is warranted in this area. Utilization of a single lot of sheathed thermocouples in a zone box configuration is a cost-effective, accurate, and reliable means of measuring temperatures in the repository environment. Care must be taken to tailor the sheath composition to the test thermal and chemical environment. Monitoring and post-test studies will continue at the SFT-C through 1984. Included in these studies will be post-test calibrations of all accessible instrumentation. A final report on the performance of the field instrumentation will be prepared at that time.

  3. Preliminary total-system analysis of a potential high-level nuclear waste repository at Yucca Mountain

    SciTech Connect

    Eslinger, P.W.; Doremus, L.A.; Engel, D.W.; Miley, T.B.; Murphy, M.T.; Nichols, W.E.; White, M.D.; Langford, D.W.; Ouderkirk, S.J.

    1993-01-01

    The placement of high-level radioactive wastes in mined repositories deep underground is considered a disposal method that would effectively isolate these wastes from the environment for long periods of time. This report describes modeling performed at PNL for Yucca Mountain between May and November 1991 addressing the performance of the entire repository system related to regulatory criteria established by the EPA in 40 CFR Part 191. The geologic stratigraphy and material properties used in this study were chosen in cooperation with performance assessment modelers at Sandia National Laboratories (SNL). Sandia modeled a similar problem using different computer codes and a different modeling philosophy. Pacific Northwest Laboratory performed a few model runs with very complex models, and SNL performed many runs with much simpler (abstracted) models.

  4. Measurements of electrical conductivity for characterizing and monitoring nuclear waste repositories

    SciTech Connect

    Morrison, H.F.; Becker, A.; Lee, K.H.

    1986-11-01

    The detection of major fractures is one topic of this study but another equally important problem is to develop quantitative relationships between large scale resistivity and fracture systems in rock. There has been very little work done on this central issue. Empirical relations between resistivity and porosity have been derived on the basis of laboratory samples or from well logging, but there are no comparable 'laws' for rock masses with major fracture or joint patterns. Hydrologic models for such rocks have been recently been derived but the corresponding resistivity models have not been attempted. Resistivity due to fracture distributions with preferred orientation could be determined with such models, as could quantitative interpretation of changes as fracture aperature varies with load. This study is not only important for the assessment of a repository site, but has far ranging implications in reservoir studies for oil, gas, and geothermal resources. The electrical conductivity can be measured in two ways. Current can be injected into the ground through pairs of electrodes and corresponding voltage drops can be measured in the vicinity with other pairs of electrodes. The electrical conductivity can also be measured inductively. Instead of injecting current into the ground as described in the dc resistivity method, currents can be induced to flow by a changing magnetic field. In these inductive or electromagnetic (em) methods the interpretation depends both on transmitter-receiver geometry and frequency of operation. In principle the interpretation should be more definitive than with the dc resistivity methods. Rigorous confirmation of this statement in inhomogeneous media awaits the development of generalized inversion techniques for em methods.

  5. Supplemental Performance Analyses for Igneous Activity and Human Intrusion at the Potential High-Level Nuclear Waste Repository at Yucca Mountain

    SciTech Connect

    Swift, P.; Gaither, K.; Freeze, G.; McCord, J.; Kalinich, D.; Saulnier, G.; Statham, W.

    2002-02-26

    The U.S. Department of Energy (DOE) is considering the possible recommendation of a site at Yucca Mountain, Nevada, for the potential development of a geologic repository for the disposal of high-level radioactive waste and spent nuclear fuel. Consequences of hypothetical disruption of the Yucca Mountain site by igneous activity or human intrusion have been evaluated in the Yucca Mountain Science and Engineering Report (S&ER) (1), which presents technical information supporting the consideration of the possible site recommendation. Since completion of the S&ER, supplemental analyses have examined possible impacts of new information and alternative assumptions on the estimates of the consequences of these events. Specifically, analyses of the consequences of igneous disruption address uncertainty regarding: (1) the impacts of changes in the repository footprint and waste package spacing on the probability of disruption; (2) impacts of alternative assumptions about the appropriat e distribution of future wind speeds to use in the analysis; (3) effects of alternative assumptions about waste particle sizes; and (4) alternative assumptions about the number of waste packages damaged by igneous intrusion; and (5) alternative assumptions about the exposure pathways and the biosphere dose conversion factors used in the analysis. Additional supplemental analyses, supporting the Final Environmental Impact Statement (FEIS), have examined the results for both igneous disruption and human intrusion, recalculated for a receptor group located 18 kilometers (km) from the repository (the location specified in 40 CFR 197), rather than at the 20 km distance used in the S&ER analyses.

  6. A literature review of coupled thermal-hydrologic-mechanical-chemical processes pertinent to the proposed high-level nuclear waste repository at Yucca Mountain

    SciTech Connect

    Manteufel, R.D.; Ahola, M.P.; Turner, D.R.; Chowdhury, A.H.

    1993-07-01

    A literature review has been conducted to determine the state of knowledge available in the modeling of coupled thermal (T), hydrologic (H), mechanical (M), and chemical (C) processes relevant to the design and/or performance of the proposed high-level waste (HLW) repository at Yucca Mountain, Nevada. The review focuses on identifying coupling mechanisms between individual processes and assessing their importance (i.e., if the coupling is either important, potentially important, or negligible). The significance of considering THMC-coupled processes lies in whether or not the processes impact the design and/or performance objectives of the repository. A review, such as reported here, is useful in identifying which coupled effects will be important, hence which coupled effects will need to be investigated by the US Nuclear Regulatory Commission in order to assess the assumptions, data, analyses, and conclusions in the design and performance assessment of a geologic reposit``. Although this work stems from regulatory interest in the design of the geologic repository, it should be emphasized that the repository design implicitly considers all of the repository performance objectives, including those associated with the time after permanent closure. The scope of this review is considered beyond previous assessments in that it attempts with the current state-of-knowledge) to determine which couplings are important, and identify which computer codes are currently available to model coupled processes.

  7. Materials in Nuclear Waste Disposition

    NASA Astrophysics Data System (ADS)

    Rebak, Raul B.

    2014-03-01

    Commercial nuclear energy has been used for over 6 decades; however, to date, none of the 30+ countries with nuclear power has opened a repository for high-level waste (HLW). All countries with nuclear waste plan to dispose of it in metallic containers located in underground geologically stable repositories. Some countries also have liquid nuclear waste that needs to be reduced and vitrified before disposition. The five articles included in this topic offer a cross section of the importance of alloy selection to handle nuclear waste at the different stages of waste processing and disposal.

  8. Characteristics of potential repository wastes

    SciTech Connect

    Cowart, C.G.; Notz, K.J.

    1992-10-01

    This report presents the results of a fully documented peer review of DOE/RW-0184, Rev. 1, Characteristics of Potential Repository Wastes''. The peer review was chaired and administered by oak Ridge National Laboratory (ORNL) for the Department of Energy (DOE), Office of Civilian Radioactive Waste Management (OCRWM) and was conducted in accordance with OCRWM QA procedure QAAP 3.3 Peer Review'' for the purpose of quailing the document for use in OCRWM quality-affecting work. The peer reviewers selected represent a wide range of experience and knowledge particularly suitable for evaluating the subject matter. A total of 596 formal comments were documented by the seven peer review panels, and all were successfully resolved. The peers reached the conclusion that DOE/RW-0184, Rev. 1, is quality determined and suitable for use in quality-affecting work.

  9. Results from an International Simulation Study on Couples Thermal, Hydrological, and Mechanical (THM) Processes Near Geological Nuclear Waste Repositories

    SciTech Connect

    J. Rutqvist; J.T> Birkholzer; M. Chijimatsu; O. Kolditz; Q.S. Liu; Y. Oda; W. Wang; C.Y. Zhang

    2006-02-01

    As part of the ongoing international code comparison project DECOVALEX, four research teams used five different models to simulate coupled thermal, hydrological, and mechanical (THM) processes near underground waste emplacement drifts. The simulations were conducted for two generic repository types with open or back-filled repository drifts under higher and lower post-closure temperature, respectively. In the completed first model inception phase of the project, a good agreement was achieved between the research teams in calculating THM responses for both repository types, although some disagreement in hydrological responses are currently being resolved. Good agreement in the basic thermal-mechanical responses was achieved for both repository types, even with some teams using relatively simplified thermal-elastic heat-conduction models that neglect complex near-field thermal-hydrological processes. The good agreement between the complex and simplified (and well-known) process models indicates that the basic thermal-mechanical responses can be predicted with a relatively high confidence level. The research teams have now moved on to the second phase of the project, the analysis of THM-induced permanent (irreversible) changes and the impact of those changes on the fluid flow field near an emplacement drift.

  10. Nuclear criticality safety analysis of a spent fuel waste package in a tuff repository

    SciTech Connect

    Weren, B.H.; Capo, M.A.; O`Neal, W.C.

    1983-12-01

    An assessment has been performed of the criticality potential associated with the disposal of spent fuel in a tuff geology above the water table. Eleven potential configurations were defined which cover a vast range of geometries and conditions from the nominal configuration at emplacement to a hypothetical configuration thousands of years after emplacement in which the structure is gone, the fuel pellets disintegrated and the borehole flooded. Of these eleven configurations, four have been evaluated at this time. The results of this evaluation indicate that even with very conservative assumptions (4.5 w/o fresh fuel), criticality is not a problem for the nominal configuration either dry or fully flooded. In the cases where the condition of the waste package is assumed to have severely deteriorated, over long times, calculations were performed with less conservative assumptions (depleted fuel). An assessment of these calculations indicates that criticality safety could be demonstrated if the depletion of the fissile inventory during fuel irradiation is taken into account. A detailed discussion of the calculations performed is presented in this report. Also included are a description of the configurations which were considered, the analytical methods and models used, and a discussion of additional related work which should be performed. 15 references, 11 figures, 8 tables.

  11. Identification and characterization of potential discharge areas for radionuclide transport by groundwater from a nuclear waste repository in Sweden.

    PubMed

    Berglund, Sten; Bosson, Emma; Selroos, Jan-Olof; Sassner, Mona

    2013-05-01

    This paper describes solute transport modeling carried out as a part of an assessment of the long-term radiological safety of a planned deep rock repository for spent nuclear fuel in Forsmark, Sweden. Specifically, it presents transport modeling performed to locate and describe discharge areas for groundwater potentially carrying radionuclides from the repository to the surface where man and the environment could be affected by the contamination. The modeling results show that topography to large extent determines the discharge locations. Present and future lake and wetland objects are central for the radionuclide transport and dose calculations in the safety assessment. Results of detailed transport modeling focusing on the regolith and the upper part of the rock indicate that the identification of discharge areas and objects considered in the safety assessment is robust in the sense that it does not change when a more detailed model representation is used.

  12. Perceived risk, stigma, and potential economic impacts of a high-level nuclear waste repository in Nevada

    SciTech Connect

    Slovic, P.

    1989-12-31

    This paper addresses the potential for the proposed Yucca Mountain repository to have serious adverse economic impacts on the city of Las Vegas and the State of Nevada. Adverse economic impacts may be expected to result from two related social processes. One has to do with perceptions of risk and socially amplified reactions to unfortunate events associated with the repository (major and minor accidents, discoveries of radiation releases, evidence of mismanagement, attempts to sabotage or disrupt the facility, etc.). The second process that may trigger significant adverse impacts is that of stigmatization. The conceptual underpinnings of risk perception, social amplification, and stigma are discussed in this paper and empirical data are presented to demonstrate how nuclear images associated with Las Vegas and the State of Nevada might trigger adverse effects on tourism, migration, and business development.

  13. Bridging the Gap in the Chemical Thermodynamic Database for Nuclear Waste Repository: Studies of the Effect of Temperature on Actinide Complexation

    SciTech Connect

    Rao, Linfeng; Tian, Guoxin; Xia, Yuanxian; Friese, Judah I.; Zanonato, PierLuigi; Di Bernardo, Plinio

    2009-12-21

    Recent results of thermodynamic studies on the complexation of actinides (UO{sub 2}{sup 2+}, NpO{sub 2}{sup +} and Pu{sup 4+}) with F{sup -}, SO{sub 4}{sup 2-} and H{sub 2}PO{sub 4}{sup -}/HPO{sub 4}{sup 2-} at elevated temperatures are reviewed. The data indicate that, for all systems except the 1:1 complexation of Np(V) with HPO{sub 4}{sup 2-}, the complexation of actinides is enhanced by the increase in temperature. The enhancement is primarily due to the increase in the entropy term (T{Delta}S) that exceeds the increase in the enthalpy ({Delta}H) as the temperature is increased. These data bridge the gaps in the chemical thermodynamic database for nuclear waste repository where the temperature could remain significantly higher than 25 C for a long time after the closure of the repository.

  14. Investigation of environmentally assisted fracture of metallic nuclear waste package barrier materials in simulated basalt repository environments

    SciTech Connect

    Pitman, S.G.

    1982-11-01

    Statically loaded corrosion tests, slow strain rate (SSR) tests, and fatigue crack growth rate (FCGR) tests were conducted to evaluate the relative susceptibility of two titanium-base nuclear waste package candidate structural barrier materials Ti-grade 2 and Ti-grade 12-to environmentally enhanced cracking in a simulated repository environment. Statically loaded corrosion tests were done in oxic basalt ground water at 250/sup 0/C; SSR tests were done in oxic basalt ground water at 150, 250, and 300/sup 0/C and in air at 20 and 250/sup 0/C; and FCGR tests were done in basalt ground water, fluoride-ion-enhanced basalt ground water, high-purity water, and air at 90/sup 0/C. The following conclusions can be drawn: the general corrosion rate of statically loaded corrosion coupons was very low in a 3-mo test, and no pitting or cracking of the specimens was observed. Ti-grade 2 and Ti-grade 12 exhibited strain rate dependent ductility diminution in SSR tests. The ductility diminution was most severe in Ti-grade 2 at 300/sup 0/C and in Ti-grade 12 at 250/sup 0/C. For of Ti-grade 12 it was found to be highly orientation dependent. The ductility diminution was also found in tests conducted in air as well as in those conducted in the basalt ground water environment; however, the extent of the degradation was less in air. The ductility diminution cannot be attributed to stress corrosion cracking because the fracture mode was microvoid coalescence in all tests. Evidence obtained in the current study and correlation of the present results with results obtained by other researchers indicate that dynamic strain aging is responsible for the loss of ductility. The FCGR of Ti-grade 2 and Ti-grade 12 was not affected by any of the environmental conditions used in this study, which indicates that no environmental cracking mechanism is operative under the conditions tested (90/sup 0/C, oxic ground water, and frequencies from 0.01 to 5 Hz).

  15. Long-Term Modeling of Coupled Processes in a Generic Salt Repository for Heat-Generating Nuclear Waste: Analysis of the Impacts of Halite Solubility Constraints

    NASA Astrophysics Data System (ADS)

    Blanco Martin, L.; Rutqvist, J.; Battistelli, A.; Birkholzer, J. T.

    2015-12-01

    Rock salt is a potential medium for the underground disposal of nuclear waste because it has several assets, such as its ability to creep and heal fractures and its water and gas tightness in the undisturbed state. In this research, we focus on disposal of heat-generating nuclear waste and we consider a generic salt repository with in-drift emplacement of waste packages and crushed salt backfill. As the natural salt creeps, the crushed salt backfill gets progressively compacted and an engineered barrier system is subsequently created [1]. The safety requirements for such a repository impose that long time scales be considered, during which the integrity of the natural and engineered barriers have to be demonstrated. In order to evaluate this long-term integrity, we perform numerical modeling based on state-of-the-art knowledge. Here, we analyze the impacts of halite dissolution and precipitation within the backfill and the host rock. For this purpose, we use an enhanced equation-of-state module of TOUGH2 that properly includes temperature-dependent solubility constraints [2]. We perform coupled thermal-hydraulic-mechanical modeling and we investigate the influence of the mentioned impacts. The TOUGH-FLAC simulator, adapted for large strains and creep, is used [3]. In order to quantify the importance of salt dissolution and precipitation on the effective porosity, permeability, pore pressure, temperature and stress field, we compare numerical results that include or disregard fluids of variable salinity. The sensitivity of the results to some parameters, such as the initial saturation within the backfill, is also addressed. References: [1] Bechthold, W. et al. Backfilling and Sealing of Underground Repositories for Radioactive Waste in Salt (BAMBUS II Project). Report EUR20621 EN: European Atomic Energy Community, 2004. [2] Battistelli A. Improving the treatment of saline brines in EWASG for the simulation of hydrothermal systems. Proceedings, TOUGH Symposium 2012

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

    SciTech Connect

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

    1990-06-01

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

  17. Thermal-Hydrologic-Mechanical Study of Pre-Closure Off-Normal Thermal Scenarios at the Proposed Yucca Mountain Nuclear Waste Repository

    SciTech Connect

    J. Leem; M. Lin; Y. Sun; D. Kicker

    2005-03-09

    The proposed nuclear waste repository at Yucca Mountain, Nevada currently includes a minimum of 50 years forced ventilation inside of emplacement drifts prior to repository closure. To regulate the heat generated from emplaced waste packages, the ventilation during the pre-closure period should be continuous. Off-normal thermal scenarios that consider temporary shutdown of the pre-closure ventilation are investigated to determine the impacts of ventilation shutdown on the thermal-hydrologic-mechanical behaviors of the emplacement drifts. In-drift heat transfer processes including radiation, convection, and conduction are studied. The analysis provides a ventilation heat removal ratio that varies on the drift location and the ventilation duration. The heat removal ratio is transferred and utilized in the NUFT thermal-hydrology software. The NUFT software is used to investigate the thermal-hydrologic impacts on the repository rock mass for the off-normal thermal scenarios with various shutdown durations at various pre-closure times. The predicted rock mass temperature evaluated from the thermal-hydrologic analysis is applied for the thermal-mechanical analysis of the off-normal thermal scenarios. The results show that degradation and rockfall of the emplacement drifts due to the off-normal thermal scenarios will be minimal, and it is concluded that the impacts of off-normal thermal scenarios on the stability of the emplacement drifts will be insignificant.

  18. Review of revegetation practices appropriate for reclamation of the proposed nuclear waste repository at Yucca Mountain, Nevada

    SciTech Connect

    1989-10-01

    The Yucca Mountain site, proposed by US Department of Energy (DOE) as the nation`s first high-level radioactive waste repository is located in Nye County, Nevada, approximately 100 miles northwest of Las Vegas. Yucca Mountain is located in a botanically unique transition zone between the Great Basin and the Mojave Desert. The environment of the proposed repository is influenced by both biotic provinces, and additionally possesses characteristics that are unique unto itself. The purpose of this report is to summarize the existing pertinent data relative to the local environmental constraints that affect reclamation; describe the observations that have been made regarding vegetation reestablishment in the absence of reclamation; and provide special horticultural considerations appropriate for harsh environments such as Yucca Mountain. Further, this report provides specific recommendations to acquire further more specific information needed to refine reclamation prescriptions specifically for Yucca Mountain. Finally, this report describes the time and procedural commitment that must be made to monitor reclamation success. 43 refs., 1 tab.

  19. Multi-scale groundwater flow modeling during temperate climate conditions for the safety assessment of the proposed high-level nuclear waste repository site at Forsmark, Sweden

    NASA Astrophysics Data System (ADS)

    Joyce, Steven; Hartley, Lee; Applegate, David; Hoek, Jaap; Jackson, Peter

    2014-09-01

    Forsmark in Sweden has been proposed as the site of a geological repository for spent high-level nuclear fuel, to be located at a depth of approximately 470 m in fractured crystalline rock. The safety assessment for the repository has required a multi-disciplinary approach to evaluate the impact of hydrogeological and hydrogeochemical conditions close to the repository and in a wider regional context. Assessing the consequences of potential radionuclide releases requires quantitative site-specific information concerning the details of groundwater flow on the scale of individual waste canister locations (1-10 m) as well as details of groundwater flow and composition on the scale of groundwater pathways between the facility and the surface (500 m to 5 km). The purpose of this article is to provide an illustration of multi-scale modeling techniques and the results obtained when combining aspects of local-scale flows in fractures around a potential contaminant source with regional-scale groundwater flow and transport subject to natural evolution of the system. The approach set out is novel, as it incorporates both different scales of model and different levels of detail, combining discrete fracture network and equivalent continuous porous medium representations of fractured bedrock.

  20. Repository disposal requirements for commercial transuranic wastes (generated without reprocessing)

    SciTech Connect

    Daling, P.M.; Ludwick, J.D.; Mellinger, G.B.; McKee, R.W.

    1986-06-01

    This report forms a preliminary planning basis for disposal of commercial transuranic (TRU) wastes in a geologic repository. Because of the unlikely prospects for commercial spent nuclear fuel reprocessing in the near-term, this report focuses on TRU wastes generated in a once-through nuclear fuel cycle. The four main objectives of this study were to: develop estimates of the current inventories, projected generation rates, and characteristics of commercial TRU wastes; develop proposed acceptance requirements for TRU wastes forms and waste canisters that ensure a safe and effective disposal system; develop certification procedures and processing requirements that ensure that TRU wastes delivered to a repository for disposal meet all applicable waste acceptance requirements; and identify alternative conceptual strategies for treatment and certification of commercial TRU first objective was accomplished through a survey of commercial producers of TRU wastes. The TRU waste acceptance and certification requirements that were developed were based on regulatory requirements, information in the literature, and from similar requirements already established for disposal of defense TRU wastes in the Waste Isolation Pilot Plant (WIPP) which were adapted, where necessary, to disposal of commercial TRU wastes. The results of the TRU waste-producer survey indicated that there were a relatively large number of producers of small quantities of TRU wastes.

  1. YUCCA MOUNTAIN PROJECT RECOMMENDATION BY THE SECRETARY OF ENERGY REGARDING THE SUITABILITY OF THE YUCCA MOUNTAIN SITE FOR A REPOSITORY UNDER THE NUCLEAR WASTE POLICY ACT OF 1982

    SciTech Connect

    NA

    2002-03-26

    For more than half a century, since nuclear science helped us win World War II and ring in the Atomic Age, scientists have known that !he Nation would need a secure, permanent facility in which to dispose of radioactive wastes. Twenty years ago, when Congress adopted the Nuclear Waste Policy Act of 1982 (NWPA or ''the Act''), it recognized the overwhelming consensus in the scientific community that the best option for such a facility would be a deep underground repository. Fifteen years ago, Congress directed the Secretary of Energy to investigate and recommend to the President whether such a repository could be located safely at Yucca Mountain, Nevada. Since then, our country has spent billions of dollars and millions of hours of research endeavoring to answer this question. I have carefully reviewed the product of this study. In my judgment, it constitutes sound science and shows that a safe repository can be sited there. I also believe that compelling national interests counsel in favor of proceeding with this project. Accordingly, consistent with my responsibilities under the NWPA, today I am recommending that Yucca Mountain be developed as the site for an underground repository for spent fuel and other radioactive wastes. The first consideration in my decision was whether the Yucca Mountain site will safeguard the health and safety of the people, in Nevada and across the country, and will be effective in containing at minimum risk the material it is designed to hold. Substantial evidence shows that it will. Yucca Mountain is far and away the most thoroughly researched site of its kind in the world. It is a geologically stable site, in a closed groundwater basin, isolated on thousands of acres of Federal land, and farther from any metropolitan area than the great majority of less secure, temporary nuclear waste storage sites that exist in the country today. This point bears emphasis. We are not confronting a hypothetical problem. We have a staggering amount of

  2. Final repository for Denmark's low- and intermediate level radioactive waste

    NASA Astrophysics Data System (ADS)

    Nilsson, B.; Gravesen, P.; Petersen, S. S.; Binderup, M.

    2012-12-01

    Bertel Nilsson*, Peter Gravesen, Stig A. Schack Petersen, Merete Binderup Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, 1350 Copenhagen, Denmark, * email address bn@geus.dk The Danish Parliament decided in 2003 that the temporal disposal of the low- and intermediate level radioactive waste at the nuclear facilities at Risø should find another location for a final repository. The Danish radioactive waste must be stored on Danish land territory (exclusive Greenland) and must hold the entire existing radioactive waste, consisting of the waste from the decommissioning of the nuclear facilities at Risø, and the radioactive waste produced in Denmark from hospitals, universities and industry. The radioactive waste is estimated to a total amount of up to 10,000 m3. The Geological Survey of Denmark and Greenland, GEUS, is responsible for the geological studies of suitable areas for the repository. The task has been to locate and recognize non-fractured Quaternary and Tertiary clays or Precambrian bedrocks with low permeability which can isolate the radioactive waste from the surroundings the coming more than 300 years. Twenty two potential areas have been located and sequential reduced to the most favorable two to three locations taking into consideration geology, hydrogeology, nature protection and climate change conditions. Further detailed environmental and geology investigations will be undertaken at the two to three potential localities in 2013 to 2015. This study together with a study of safe transport of the radioactive waste and an investigation of appropriate repository concepts in relation to geology and safety analyses will constitute the basis upon which the final decision by the Danish Parliament on repository concept and repository location. The final repository is planned to be established and in operation at the earliest 2020.

  3. Illitization within bentonite engineered barrier system in clay repositories for nuclear waste and its effect on the swelling stress: a coupled THMC modeling study

    NASA Astrophysics Data System (ADS)

    Zheng, L.; Rutqvist, J.; Birkholzer, J. T.; Liu, H. H.

    2014-12-01

    Geological repositories for disposal of high-level nuclear waste generally rely on a multi-barrier system to isolate radioactive waste from the biosphere. An engineered barrier system (EBS), which comprises in many design concepts a bentonite backfill, is widely used. Clay formations have been considered as a host rock throughout the world. Illitization, the transformation of smectite to illite, could compromise some beneficiary features of EBS bentonite and clay host rock such as sorption and swelling capacity. It is the major determining factor to establish the maximum design temperature of the repositories because it is believed that illitization could be greatly enhanced at temperatures higher than 100 oC. However, existing experimental and modeling studies on the occurrence of illitization and related performance impacts are not conclusive, in part because the relevant couplings between the thermal, hydrological, chemical, and mechanical (THMC) processes have not been fully represented in the models. Here we present a fully coupled THMC simulation study of a generic nuclear waste repository in a clay formation with a bentonite-backfilled EBS. Two scenarios were simulated for comparison: a case in which the temperature in the bentonite near the waste canister can reach about 200 oC and a case in which the temperature in the bentonite near the waste canister peaks at about 100 oC. The model simulations demonstrate that illitization is in general more significant under higher temperature. However, the quantity of illitization is affected by many chemical factors and therefore varies a great deal. The most important chemical factors are the concentration of K in the pore water as well as the abundance and dissolution rate of K-feldspar. For the particular case and bentonite properties studied, the reduction in swelling stress as a result of chemical changes vary from 2% up to 70% depending on chemical and temperature conditions, and key mechanical parameters. The

  4. Final Systems Development Report for the Clark County Socioeconomic Impact Assessment of the Proposed High-Level Nuclear Waste Repository at Yucca Mountain, NV

    SciTech Connect

    1992-06-18

    The Systems Development Report represents the third major step in the Clark County Socioeconomic Impact Assessment of the Proposed High-Level Nuclear Waste Repository at Yucca Mound Nevada. The first of these steps was to forge a Research Design that would serve as a guide for the overall research process. The second step was the construction of the Base Case, the purpose of which was to describe existing conditions in Clark County in the specified analytic areas of Economic-Demographic/Fiscal, Emergency Planning and Management, Transportation and Sociocultural analysis. The base case description will serve as a basis for assessing changes in these topic areas that might result from the Yucca Mountain project. These changes will be assessed by analyzing conditions with and without repository development in the county. Prior to performing such assessments, however, the snapshot type of data found in the base case must be operationalized or systematized to allow for more dynamic data utilization. In other words, a data system that can be used to analyze the consequences of the introduction of different variables (or variable values) in the Clark County context must be constructed. Such a system must be capable of being updated through subsequent data collection and monitoring efforts to both provide a rolling base case and supply information necessary to construct trend analyses. For example, during the Impact Assessment phase of the study process, the without repository analysis is accomplished by analyzing growth for the county given existing conditions and likely trends. These data are then compared to the with Yucca Mountain project conditions anticipated for the county. Similarly, once the emergency planning management and response needs associated with the repository are described, these needs will be juxtaposed against existing (and various future) capacity(ies) in order to determine the nature and magnitude of impacts in this analytic area. Analogous tasks

  5. Final base case community analysis: Indian Springs, Nevada for the Clark County socioeconomic impact assessment of the proposed high- level nuclear waste repository at Yucca Mountain, Nevada

    SciTech Connect

    1992-06-18

    This document provides a base case description of the rural Clark County community of Indian Springs in anticipation of change associated with the proposed high-level nuclear waste repository at Yucca Mountain. As the community closest to the proposed site, Indian Springs may be seen by site characterization workers, as well as workers associated with later repository phases, as a logical place to live. This report develops and updates information relating to a broad spectrum of socioeconomic variables, thereby providing a `snapshot` or `base case` look at Indian Springs in early 1992. With this as a background, future repository-related developments may be analytically separated from changes brought about by other factors, thus allowing for the assessment of the magnitude of local changes associated with the proposed repository. Given the size of the community, changes that may be considered small in an absolute sense may have relatively large impacts at the local level. Indian Springs is, in many respects, a unique community and a community of contrasts. An unincorporated town, it is a small yet important enclave of workers on large federal projects and home to employees of small- scale businesses and services. It is a rural community, but it is also close to the urbanized Las Vega Valley. It is a desert community, but has good water resources. It is on flat terrain, but it is located within 20 miles of the tallest mountains in Nevada. It is a town in which various interest groups diverge on issues of local importance, but in a sense of community remains an important feature of life. Finally, it has a sociodemographic history of both surface transience and underlying stability. If local land becomes available, Indian Springs has some room for growth but must first consider the historical effects of growth on the town and its desired direction for the future.

  6. Workshop on the source term for radionuclide migration from high-level waste or spent nuclear fuel under realistic repository conditions: proceedings

    SciTech Connect

    Hunter, T.O.; Muller, A.B.

    1985-07-01

    Sixteen papers were presented at the workshop. The fourteen full-length papers included in the proceedings were processed separately. Only abstracts were included for the following two papers: Data Requirements Based on Performance Assessment Analyses of Conceptual Waste Packages in Salt Repositories, and The Potential Effects of Radiation on the Source Term in a Salt Repository. (LM)

  7. Surveys for desert tortoise on the proposed site of a high-level nuclear waste repository at the Nevada Test Site

    SciTech Connect

    Collins, E.; Sauls, M.L.; O`Farrell, T.P.

    1983-12-31

    The National Waste Terminal Storage Program is a national search for suitable sites to isolate commercial spent nuclear fuel or high-level radioactive waste. The Nevada Nuclear Waste Storage Investigation (NNWSI) managed by the U.S. Department of Energy (DOE), Nevada Operations Office, was initiated to study the suitability of a portion of Yucca Mountain on the DOE`s Nevada Test Site (NTS) as a location for such a repository. EG and G was contracted to provide information concerning the ecosystems encountered on the site. A comprehensive literature survey was conducted to evaluate the status and completeness of the existing biological information for the previously undisturbed area. Site specific studies were begun in 1981 when preliminary field surveys confirmed the presence of the desert tortoise (Gopherus agassizi) within the project area FY82 studies were designed to determine the overall distribution and abundance of the tortoise within the area likely to be impacted by NNWSI activities. The Yucca Mountain area of the Nevada Test Site is situated close to the northern range limit of the desert tortoise. Prior to the 1982 surveys, the desert tortoise was reported from only nine locations on NTS. A known population had been under study in Rock Valley about 25 miles southeast of the project area. However, the distribution and population densities of tortoise in the southwest portion of NTS were virtually unknown. Results of our surveys indicate that desert tortoise can be expected, albeit in small numbers, in a wide range of Mojavean and Transitional habitats.

  8. Milestones for Selection, Characterization, and Analysis of the Performance of a Repository for Spent Nuclear Fuel and High-Level Radioactive Waste at Yucca Mountain.

    SciTech Connect

    Rechard, Robert P.

    2014-02-01

    This report presents a concise history in tabular form of events leading up to site identification in 1978, site selection in 1987, subsequent characterization, and ongoing analysis through 2008 of the performance of a repository for spent nuclear fuel and high-level radioactive waste at Yucca Mountain in southern Nevada. The tabulated events generally occurred in five periods: (1) commitment to mined geologic disposal and identification of sites; (2) site selection and analysis, based on regional geologic characterization through literature and analogous data; (3) feasibility analysis demonstrating calculation procedures and importance of system components, based on rough measures of performance using surface exploration, waste process knowledge, and general laboratory experiments; (4) suitability analysis demonstrating viability of disposal system, based on environment-specific laboratory experiments, in-situ experiments, and underground disposal system characterization; and (5) compliance analysis, based on completed site-specific characterization. Because the relationship is important to understanding the evolution of the Yucca Mountain Project, the tabulation also shows the interaction between four broad categories of political bodies and government agencies/institutions: (a) technical milestones of the implementing institutions, (b) development of the regulatory requirements and related federal policy in laws and court decisions, (c) Presidential and agency directives and decisions, and (d) critiques of the Yucca Mountain Project and pertinent national and world events related to nuclear energy and radioactive waste.

  9. Actinide Sorption in a Brine/Dolomite Rock System: Evaluating the Degree of Conservatism in Kd Ranges used in Performance Assessment Modeling for the WIPP Nuclear Waste Repository

    NASA Astrophysics Data System (ADS)

    Dittrich, T. M.; Reed, D. T.

    2015-12-01

    The Waste Isolation Pilot Plant (WIPP) near Carlsbad, NM is the only operating nuclear waste repository in the US and has been accepting transuranic (TRU) waste since 1999. The WIPP is located in a salt deposit approximately 650 m below the surface and performance assessment (PA) modeling for a 10,000 year period is required to recertify the operating license with the US EPA every five years. The main pathway of concern for environmental release of radioactivity is a human intrusion caused by drilling into a pressurized brine reservoir below the repository. This could result in the flooding of the repository and subsequent transport in the high transmissivity layer (dolomite-rich Culebra formation) above the waste disposal rooms. We evaluate the degree of conservatism in the estimated sorption partition coefficients (Kds) ranges used in the PA based on an approach developed with granite rock and actinides (Dittrich and Reimus, 2015; Dittrich et al., 2015). Sorption onto the waste storage material (Fe drums) may also play a role in mobile actinide concentrations. We will present (1) a conceptual overview of how Kds are used in the PA model, (2) technical background of the evolution of the ranges and (3) results from batch and column experiments and model predictions for Kds with WIPP dolomite and clays, brine with various actinides, and ligands (e.g., acetate, citrate, EDTA) that could promote transport. The current Kd ranges used in performance models are based on oxidation state and are 5-400, 0.5-10,000, 0.03-200, and 0.03-20 mL g-1 for elements with oxidation states of III, IV, V, and VI, respectively. Based on redox conditions predicted in the brines, possible actinide species include Pu(III), Pu(IV), U(IV), U(VI), Np(IV), Np(V), Am(III), and Th(IV). We will also discuss the challenges of upscaling from lab experiments to field scale predictions, the role of colloids, and the effect of engineered barrier materials (e.g., MgO) on transport conditions. Dittrich

  10. On the importance of coupled THM processes to predict the long-term response of a generic salt repository for high-level nuclear waste

    NASA Astrophysics Data System (ADS)

    Blanco Martin, L.; Rutqvist, J.; Birkholzer, J. T.

    2013-12-01

    Salt is a potential medium for the underground disposal of nuclear waste because it has several assets, in particular its ability to creep and heal fractures generated by excavation and its water and gas tightness in the undisturbed state. In this research, we focus on disposal of heat-generating nuclear waste (such as spent fuel) and we consider a generic salt repository with in-drift emplacement of waste packages and subsequent backfill of the drifts with run-of-mine crushed salt. As the natural salt creeps, the crushed salt backfill gets progressively compacted and an engineered barrier system is subsequently created. In order to evaluate the integrity of the natural and engineered barriers over the long-term, it is important to consider the coupled effects of the thermal, hydraulic and mechanical processes that take place. In particular, the results obtained so far show how the porosity reduction of the crushed salt affects the saturation and pore pressure evolution throughout the repository, both in time and space. Such compaction is induced by the stress and temperature regime within the natural salt. Also, transport properties of the host rock are modified not only by thermo-mechanically and hydraulically-induced damaged processes, but also by healing/sealing of existing fractures. In addition, the THM properties of the backfill evolve towards those of the natural salt during the compaction process. All these changes are based on dedicated laboratory experiments and on theoretical considerations [1-3]. Different scenarios are modeled and compared to evaluate the relevance of different processes from the perspective of effective nuclear waste repositories. The sensitivity of the results to some parameters, such as capillarity, is also addressed. The simulations are conducted using an updated version of the TOUGH2-FLAC3D simulator, which is based on a sequential explicit method to couple flow and geomechanics [4]. A new capability for large strains and creep

  11. Axisymmetric analysis of multilayered thermoelastic media with application to a repository for heat-emitting high-level nuclear waste in a geological formation

    NASA Astrophysics Data System (ADS)

    Yang, Yang; Datcheva, Maria; Schanz, Tom

    2016-08-01

    Comprehensive analytical solutions to 3-D axisymmetric problems for static response of multilayered thermoelastic media subjected to surface loads and containing sources are presented in this study. The solution strategy employs Laplace and Hankel transforms to the field variables. The problem is formulated in cylindrical coordinate system and in this coordinate system vector surface harmonics and generalized propagator matrix are introduced to find the solution for the problem for the behaviour of thermoelastic multilayered media subject to surface loads and containing heat sources. A high-order adaptive Gaussian quadrature method with continued fraction expansions is employed to approximate the integral solutions expressed in terms of semi-infinite Hankel-type integrals. It is the first time to apply the proposed solution method to investigate the behaviour of repository for heat-emitting high-level nuclear waste (HLW) in a geological formation where the HLW can be regarded as a decaying with time point heat source.

  12. Multiple-Code BenchMaek Simulation Stidy of Coupled THMC Processes IN the EXCAVATION DISTURBED ZONE Associated with Geological Nuclear Waste Repositories

    SciTech Connect

    J. Rutqvist; X. Feng; J. Hudson; L. Jing; A. Kobayashi; T. Koyama; P.Pan; H. Lee; M. Rinne; E. Sonnenthal; Y. Yamamoto

    2006-05-08

    An international, multiple-code benchmark test (BMT) study is being conducted within the international DECOVALEX project to analyze coupled thermal, hydrological, mechanical and chemical (THMC) processes in the excavation disturbed zone (EDZ) around emplacement drifts of a nuclear waste repository. This BMT focuses on mechanical responses and long-term chemo-mechanical effects that may lead to changes in mechanical and hydrological properties in the EDZ. This includes time-dependent processes such as creep, and subcritical crack, or healing of fractures that might cause ''weakening'' or ''hardening'' of the rock over the long term. Five research teams are studying this BMT using a wide range of model approaches, including boundary element, finite element, and finite difference, particle mechanics, and elasto-plastic cellular automata methods. This paper describes the definition of the problem and preliminary simulation results for the initial model inception part, in which time dependent effects are not yet included.

  13. Axisymmetric Analysis of Multilayered Thermoelastic Media with Application to a Repository for Heat-Emitting High-Level Nuclear Waste in a Geological Formation

    NASA Astrophysics Data System (ADS)

    Yang, Yang; Datcheva, Maria; Schanz, Tom

    2016-05-01

    Comprehensive analytical solutions to 3D axisymmetric problems for static response of multilayered thermoelastic media subjected to surface loads and containing sources are presented in this study. The solution strategy employs Laplace and Hankel transforms to the field variables. The problem is formulated in cylindrical coordinate system and in this coordinate system vector surface harmonics and generalized propagator matrix are introduced to find the solution for the problem for the behaviour of thermoelastic multilayered media subject to surface loads and containing heat sources. A high-order adaptive Gaussian quadrature method with continued fraction expansions is employed to approximate the integral solutions expressed in terms of semi-infinite Hankel-type integrals. It is the first time to apply the proposed solution method to investigate the behaviour of repository for heat-emitting high-level nuclear waste (HLW) in a geological formation where the HLW can be regarded as a decaying with time point heat source.

  14. Basic repository waste handling and packaging facility conceptual design: Draft

    SciTech Connect

    Not Available

    1985-01-01

    This report presents the conceptual design for a surface facility capable of receiving and processing high-level nuclear waste for terminal storage in a mined repository in salt. Design parameters, provided by the Office of Nuclear Waste Isolation, include a repository capacity of 72,000 metric tons of heavy metal. Waste form to be received consists of spent fuel elements and boxed spent fuel pins, to be disassembled and packed into long-lived waste packages; canisters of commercial and defense high-level waste, inserted into the waste packages without disassembly; and transuranic waste, which requires no further packaging before burial. Activities within the facility cover receipt of waste by rail or truck, inspection, cleaning, decontamination, and unloading; waste from segregation to the appropriate hot cell or handling area; disassembly and packaging, overpacking, or palletizing; and loading onto the waste shaft hoist in transfer casks manipulated by overhead bridge cranes. The building's ground-floor design encompasses 18,795 m/sup 2/ (202,200 ft/sup 2/). Support systems include separate ventilation systems for the various functional areas with high-efficiency filtration, which provides the major engineered safeguard for containment of radioactive materials. The total life-cycle cost of the handling and packaging facility, if located in the Palo Duro Basin, is estimated at $1246 million. 10 refs., 31 figs., 10 tabs.

  15. On-line remote monitoring of radioactive waste repositories

    NASA Astrophysics Data System (ADS)

    Calì, Claudio; Cosentino, Luigi; Litrico, Pietro; Pappalardo, Alfio; Scirè, Carlotta; Scirè, Sergio; Vecchio, Gianfranco; Finocchiaro, Paolo; Alfieri, Severino; Mariani, Annamaria

    2014-12-01

    A low-cost array of modular sensors for online monitoring of radioactive waste was developed at INFN-LNS. We implemented a new kind of gamma counter, based on Silicon PhotoMultipliers and scintillating fibers, that behaves like a cheap scintillating Geiger-Muller counter. It can be placed in shape of a fine grid around each single waste drum in a repository. Front-end electronics and an FPGA-based counting system were developed to handle the field data, also implementing data transmission, a graphical user interface and a data storage system. A test of four sensors in a real radwaste storage site was performed with promising results. Following the tests an agreement was signed between INFN and Sogin for the joint development and installation of a prototype DMNR (Detector Mesh for Nuclear Repository) system inside the Garigliano radwaste repository in Sessa Aurunca (CE, Italy). Such a development is currently under way, with the installation foreseen within 2014.

  16. Multiple-code simulation study of the long-term EDZ evolution of geological nuclear waste repositories

    SciTech Connect

    Rutqvist, J.; Backstrom, A.; Chijimatsu, M.; Feng, X.-T.; Pan, P.-Z.; Hudson, J.; Jing, L.; Kobayashi, A.; Koyama, T.; Lee, H.-S.; Huang, X.-H.; Rinne, M.; Shen, B.

    2008-10-23

    This simulation study shows how widely different model approaches can be adapted to model the evolution of the excavation disturbed zone (EDZ) around a heated nuclear waste emplacement drift in fractured rock. The study includes modeling of coupled thermal-hydrological-mechanical (THM) processes, with simplified consideration of chemical coupling in terms of time-dependent strength degradation or subcritical crack growth. The different model approaches applied in this study include boundary element, finite element, finite difference, particle mechanics, and elastoplastic cellular automata methods. The simulation results indicate that thermally induced differential stresses near the top of the emplacement drift may cause progressive failure and permeability changes during the first 100 years (i.e., after emplacement and drift closure). Moreover, the results indicate that time-dependent mechanical changes may play only a small role during the first 100 years of increasing temperature and thermal stress, whereas such time-dependency is insignificant after peak temperature, because decreasing thermal stress.

  17. Politics of nuclear waste

    SciTech Connect

    Colglazier, E.W. Jr.

    1982-01-01

    In November of 1979, the Program in Science, Technology and Humanism and the Energy Committee of the Aspen Institute organized a conference on resolving the social, political, and institutional conflicts over the permanent siting of radioactive wastes. This book was written as a result of this conference. The chapters provide a comprehensive and up-to-date overview of the governance issues connected with radioactive waste management as well as a sampling of the diverse views of the interested parties. Chapter 1 looks in depth of radioactive waste management in the United States, with special emphasis on the events of the Carter Administration as well as on the issues with which the Reagen administration must deal. Chapter 2 compares waste management policies and programs among the industralized countries. Chapter 3 examines the factional controversies in the last administration and Congress over nuclear waste issues. Chapter 4 examines the complex legal questions involved in the federal-state conflicts over nuclear waste management. Chapter 5 examines the concept of consultation and concurrence from the perspectives of a host state that is a candidate for a repository and an interested state that has special concerns regarding the demonstration of nuclear waste disposal technology. Chapter 6 examines US and European perspectives concerning public participation in nuclear waste management. Chapter 7 discusses propaganda in the issues. The epilogue attempts to assess the prospects for consensus in the United States on national policies for radioactive waste management. All of the chapter in this book should be interpreted as personal assessments. (DP)

  18. Systems study of the feasibility of high-level nuclear-waste fractionation for thermal stress control in a geologic repository: main report

    SciTech Connect

    McKee, R.W.; Elder, H.K.; McCallum, R.F.; Silviera, D.J.; Swanson, J.L.; Wiles, L.E.

    1983-06-01

    This study assesses the benefits and costs of fractionating the cesium and strontium (Cs/Sr) components in commercial high-level waste (HLW) to a separate waste stream for the purpose of reducing geologic-repository thermal stresses in the region of the HLW. System costs are developed for a broad range of conditions comparing the Cs/Sr fractionation concept with disposal of 10-year-old vitrified HLW and vitrified HLW aged to achieve (through decay) the same heat output as the fractionated high-level waste (FHLW). All comparisons are based on a 50,000 metric ton equivalent (MTE) system. The FHLW and the Cs/Sr waste are both disposed of as vitrified waste but emplaced in separate areas of a basalt repository. The FHLW is emplaced in high-integrity packages at relatively high waste loading but low heat loading, while the Cs/Sr waste is emplaced in minimum-integrity packages at relatively high heat loading in a separate region of the repository. System cost comparisons are based on minimum cost combinations of canister diameter, waste concentration, and canister spacing in a basalt repository. The effects on both long- and near-term safety considerations are also addressed. The major conclusion is that the Cs/Sr fractionation concept offers the prospect of a substantial total system cost advantage for HLW disposal if reduced HLW package temperatures in a basalt repository are desired. However, there is no cost advantage if currently designated maximum design temperatures are acceptable. Aging the HLW for 50 to 100 years can accomplish similar results at equivalent or lower costs. 37 figures, 58 tables.

  19. Research on uranium deposits as analogies of radioactive waste repositories

    SciTech Connect

    Hardy, C.J.

    1988-01-01

    The disposal of highly radioactive waste deep underground in suitable geological formations is proposed by many countries to protect public health and safety. The study of natural analogies of nuclear waste repositories is one method of validating mathematical models and assuring that a proposed repository site and design will be safe. Since 1981, the AAEC has studied the major uranium deposits in the Alligator Rivers region of the Northern Territory of Australia as natural analogues of radioactive waste repositories. Results have been obtained on the following: (1) the migration of uranium, thorium and radium isotopes, (2) the behavior of naturally occurring levels of selected fission products and transuranium nuclides, e.g. technetium-99, iodine-129 and plutonium-239; (3) the role of specific minerals in retarding migration, and (4) the importance of colloidal material, in the migration of thorium. The AAEC has initiated a wider international project entitled The Alligator Rivers Analogue Project which will enable participating organizations to obtain additional results and to apply them in modeling, planning and regulating waste repositories.

  20. Pools and fluxes of organic matter in a boreal landscape: implications for a safety assessment of a repository for nuclear waste.

    PubMed

    Kumblad, Linda; Söderbäck, Björn; Löfgren, Anders; Lindborg, Tobias; Wijnbladh, Erik; Kautsky, Ulrik

    2006-12-01

    To provide information necessary for a license application for a deep repository for spent nuclear fuel, the Swedish Nuclear Fuel and Waste Management Co is carrying out site investigations, including extensive studies of different parts of the surface ecosystems, at two sites in Sweden. Here we use the output from detailed modeling of the carbon dynamics in the terrestrial, limnic and marine ecosystems to describe and compare major pools and fluxes of organic matter in the Simpevarp area, situated on the southeast coast of Sweden. In this study, organic carbon is used as a proxy for radionuclides incorporated into organic matter. The results show that the largest incorporation of carbon into living tissue occurs in terrestrial catchments. Carbon is accumulated in soil or sediments in all ecosystems, but the carbon pool reaches the highest values in shallow near-land marine basins. The marine basins, especially the outer basins, are dominated by large horizontal water fluxes that transport carbon and any associated contaminants into the Baltic Sea. The results suggest that the near-land shallow marine basins have to be regarded as focal points for accumulation of radionuclides in the Simpevarp area, as they receive a comparatively large amount of carbon as discharge from terrestrial catchments, having a high NPP and a high detrital accumulation in sediments. These focal points may constitute a potential risk for exposure to humans in a future landscape as, due to post-glacial land uplift, previous accumulation bottoms are likely to be used for future agricultural purposes.

  1. Fabrication development for high-level nuclear waste containers for the tuff repository; Phase 1 final report

    SciTech Connect

    Domian, H.A.; Holbrook, R.L.; LaCount, D.F. |

    1990-09-01

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

  2. Comparative Simulation Syudy of Coupled THM Processes near Back-Filled and Open-Drift Nuclear Waste Repositories in Task D of International DECOVALEX Project

    SciTech Connect

    J. Rutqvist; J.T. Birkholzer; M. Chijimatsu; O. Kolditz; Q.S. Liu; Y. Oda; W. Wang; C.Y. Zhang

    2006-05-08

    As part of the ongoing international DECOVALEX project, four research teams used five different models to simulate coupled thermal, hydrological, and mechanical (THM) processes near underground waste emplacement drifts. The simulations were conducted for two generic repository types, one with open and the other with back-filled repository drifts, under higher and lower post-closure temperature, respectively. In the completed first model inception phase of the project, a good agreement was achieved between the research teams in calculating THM responses for both repository types, although some disagreement in hydrological responses are currently being resolved. Good agreement in the basic thermal-mechanical responses was also achieved for both repository types, even though some teams used relatively simplified thermal-elastic heat-conduction models that neglect complex near-field thermal-hydrological processes. The good agreement between the complex and simplified process models indicates that the basic thermal-mechanical responses can be predicted with a relatively high confidence level.

  3. A Transportation Risk Assessment Tool for Analyzing the Transport of Spent Nuclear Fuel and High-Level Radioactive Waste to the Proposed Yucca Mountain Repository

    SciTech Connect

    Ralph Best; T. Winnard; S. Ross; R. Best

    2001-08-17

    The Yucca Mountain Transportation Database was developed as a data management tool for assembling and integrating data from multiple sources to compile the potential transportation impacts presented in the Draft Environmental Impact Statement for a Geologic Repository for the Disposal of Spent Nuclear Fuel and High-Level Radioactive Waste at Yucca Mountain, Nye County, Nevada (DEIS). The database uses the results from existing models and codes such as RADTRAN, RISKIND, INTERLINE, and HIGHWAY to estimate transportation-related impacts of transporting spent nuclear fuel and high-level radioactive waste from commercial reactors and U. S. Department of Energy (DOE) facilities to Yucca Mountain. The source tables in the database are compendiums of information from many diverse sources including: radionuclide quantities for each waste type; route and route characteristics for rail, legal-weight truck, heavy haul. truck, and barge transport options; state-specific accident and fatality rates for routes selected for analysis; packaging and shipment data by waste type; unit risk factors; the complex behavior of the packaged waste forms in severe transport accidents; and the effects of exposure to radiation or the isotopic specific effects of radionclides should they be released in severe transportation accidents. The database works together with the codes RADTRAN (Neuhauser, et al, 1994) and RISKlND (Yuan, et al, 1995) to calculate incident-free dose and accident risk. For the incident-free transportation scenario, the database uses RADTRAN and RISKIND-generated data to calculate doses to offlink populations, onlink populations, people at stops, crews, inspectors, workers at intermodal transfer stations, guards at overnight stops, and escorts, as well as non-radioactive pollution health effects. For accident scenarios, the database uses RADTRAN-generated data to calculate dose risks based on ingestion, inhalation, resuspension, immersion (cloudshine), and groundshine as

  4. Mountain-Scale Coupled Thermal-Hydrological-Chemical Processes Around the Potential Nuclear Waste Repository at Yucca Mountain

    SciTech Connect

    E. Sonnenthal; C. Haukwa; N. Spycher

    2001-06-04

    The objectives of this study were to evaluate the thermal-hydrological-chemical (THC) effects on flow and geochemistry in the unsaturated zone (UZ) at Yucca Mountain at a mountain scale. The major THC processes important in the UZ are (1) mineral precipitation/dissolution affecting flow and transport to and from the potential repository, and (2) changes in the compositions of gas and liquid that may seep into drifts.

  5. Effects on groundwater flow of abandoned engineered structures for the safety assessment of the proposed high-level nuclear waste repository site at Forsmark, Sweden

    NASA Astrophysics Data System (ADS)

    Bockgård, Niclas; Marsic, Niko; Follin, Sven

    2014-09-01

    Effects on groundwater flow of abandoned engineered structures in relation to a potential geological repository for spent high-level nuclear fuel in fractured crystalline rock at the Forsmark site, Sweden, are studied by means of numerical modeling. The effects are analyzed by means of particle tracking, and transport-related performance measures are calculated. The impacts of abandoned, partially open repository tunnels are studied for two situations with different climate conditions: a "temperate" climate case with present-day boundary conditions, and a generic future "glacial" climate case with an ice sheet covering the repository. Then, the impact of abandoned open boreholes drilled through the repository is studied for present-day climate conditions. It is found that open repository tunnels and open boreholes can act as easy pathways from repository level to the ground surface; hence, they can attract a considerable proportion of particles released in the model at deposition hole positions within the repository. The changed flow field and flow paths cause some changes in the studied performance measures, i.e., increased flux at the deposition holes and decreased transport lengths and flow-related transport resistances. However, these effects are small and the transport resistance values are still high.

  6. Radioactive waste disposal in simulated peat bog repositories

    SciTech Connect

    Schell, W.R.; Massey, C.D.

    1987-01-01

    The Low Level Radioactive Waste Policy Act of 1980 and the Low Level Radioactive Waste Policy Amendments Act of 1985 have required state governments to be responsible for providing low-level waste (LLW) disposal facilities in their respective areas. Questions are (a) is the technology sufficiently advanced to ensure that radioactive wastes can be stored for 300 to 1000 yr without entering into any uncontrolled area. (b) since actual experience does not exist for nuclear waste disposal over this time period, can the mathematical models developed be tested and verified using unequivocal data. (c) how can the public perception of the problem be addressed and the potential risk assessment of the hazards be communicated. To address the technical problems of nuclear waste disposal in the acid precipitation regions of the Northern Hemisphere, a project was initiated in 1984 to evaluate an alternative method of nuclear waste disposal that may not rely completely on engineered barriers to protect the public. Certain natural biogeochemical systems have been retaining deposited materials since the last Ice Age (12,000 to 15,000 yr). It is the authors belief that the biogeochemical system of wetlands and peat bogs may provide an example of an analogue for a nuclear waste repository system that can be tested and verified over a sufficient time period, at least for the LLW disposal problem.

  7. Nuclear waste's last stand

    SciTech Connect

    Not Available

    1992-12-01

    It's hard to imagine a more unwelcome neighbor than nuclear waste. But something has to be done with the spent fuel now piling up at nuclear plants in the United States. While a handful of Indian tribes and other communities have shown interest in hosting a temporary storage site, the outcry from their neighbors and politicians may squash their plans. Now, a decade after the federal government began the search for a permanent repository, it still can't find even a temporary destination. Here's look at the problem and its consequences.

  8. Environmental program planning for the proposed high-level nuclear waste repository at Yucca Mountain, Nevada; Volume 1

    SciTech Connect

    1987-08-01

    Environmental protection during the course of siting and constructing a repository is mandated by NWPA in conjunction with various phases of repository siting and development. However, DOE has issued no comprehensive, integrated plan for environmental protection. Consequently, it is unclear how DOE will accomplish environmental assessment, monitoring, impact mitigation, and site reclamation. DOE should, therefore, defer further implementation of its current characterization program until a comprehensive environmental protection plan is available. To fulfill its oversight responsibilities the State of Nevada has proposed a comprehensive environmental program for the Yucca Mountain site that includes immediately undertaking studies to establish a 12-month baseline of environmental information at the site; adopting the DOE Site Characterization Plan (SCP) and the engineering design plans it will contain as the basis for defining the impact potential of site characterization activities; using the environmental baseline and the SCP to evaluate the efficacy of the preliminary impact analyses reported by DOE in the EA; using the SCP as the basis for discussions with federal, state, and local regulatory authorities to decide which environmental requirements apply and how they can be complied with; using the SCP, the EA impact review, and the compliance requirements to determine the scope of reclamation measures needed; and developing environmental monitoring and impact mitigation plans based on the EA impact review, compliance requirements, and anticipated reclamation needs.

  9. Scenarios constructed for the effects of tectonic processes on the potential nuclear waste repository at Yucca Mountain

    SciTech Connect

    Barr, G.E.; Borns, D.J.; Fridrich, C.

    1996-10-01

    A comprehensive collection of scenarios is presented that connect initiating tectonic events with radionuclide releases by logical and physically possible combinations or sequences of features, events and processes. The initiating tectonic events include both discrete faulting and distributed rock deformation developed through the repository and adjacent to it, as well as earthquake-induced ground motion and changes in tectonic stress at the site. The effects of these tectonic events include impacts on the engineered-barrier system, such as container rupture and failure of repository tunnels. These effects also include a wide range of hydrologic effects such as changes in pathways and flow rates in the unsaturated and saturated zones, changes in the water-table configuration, and in the development of perched-water systems. These scenarios are intended go guide performance-assessment analyses and to assist principal investigators in how essential field, laboratory, and calculational studies are used. This suite of scenarios will help ensure that all important aspects of the system disturbance related to a tectonic scenario are captured in numerical analyses. It also provides a record of all options considered by project analysts to provide documentation required for licensing agreement. The final portion of this report discusses issues remaining to be addressed with respect to tectonic activity. 105 refs.

  10. Critical assessment of seismic and geomechanics literature related to a high-level nuclear waste underground repository

    SciTech Connect

    Kana, D.D.; Vanzant, B.W.; Nair, P.K.; Brady, B.H.G.

    1991-06-01

    A comprehensive literature assessment has been conducted to determine the nature and scope of technical information available to characterize the seismic performance of an underground repository and associated facilities. Significant deficiencies were identified in current practices for prediction of seismic response of underground excavations in jointed rock. Conventional analytical methods are based on a continuum representation of the host rock mass. Field observations and laboratory experiments indicate that, in jointed rock, the behavior of the joints controls the overall performance of underground excavations. Further, under repetitive seismic loading, shear displacement develops progressively at block boundaries. Field observations correlating seismicity and groundwater conditions have provided significant information on hydrological response to seismic events. However, lack of a comprehensive model of geohydrological response to seismicity has limited the transportability conclusions from field observations. Based on the literature study, matters requiring further research in relation to the Yucca Mountain repository are identified. The report focuses on understanding seismic processes in fractured tuff, and provides a basis for work on the geohydrologic response of a seismically disturbed rock mass. 220 refs., 43 figs., 11 tabs.

  11. Natural Analogues - One Way to Help Build Public Confidence in the Predicted Performance of a Mined Geologic Repository for Nuclear Waste

    SciTech Connect

    Stuckless, J. S.

    2002-02-26

    The general public needs to have a way to judge the predicted long-term performance of the potential high-level nuclear waste repository at Yucca Mountain. The applicability and reliability of mathematical models used to make this prediction are neither easily understood nor accepted by the public. Natural analogues can provide the average person with a tool to assess the predicted performance and other scientific conclusions. For example, hydrologists with the Yucca Mountain Project have predicted that most of the water moving through the unsaturated zone at Yucca Mountain, Nevada will move through the host rock and around tunnels. Thus, seepage into tunnels is predicted to be a small percentage of available infiltration. This hypothesis can be tested experimentally and with some quantitative analogues. It can also be tested qualitatively using a variety of analogues such as (1) well-preserved Paleolithic to Neolithic paintings in caves and rock shelters, (2) biological remains preserved in caves and rock shelters, and (3) artifacts and paintings preserved in man-made underground openings. These examples can be found in materials that are generally available to the non-scientific public and can demonstrate the surprising degree of preservation of fragile and easily destroyed materials for very long periods of time within the unsaturated zone.

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

    PubMed

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

    2014-01-15

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

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

    PubMed

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

    2014-01-15

    This paper presents the mixing modelling results for the hydrogeochemical characterisation of groundwaters in the Laxemar area (Sweden). This area is one of the two sites that have been investigated, under the financial patronage of the Swedish Nuclear Waste and Management Co. (SKB), as possible candidates for hosting the proposed repository for the long-term storage of spent nuclear fuel. The classical geochemical modelling, interpreted in the light of the palaeohydrogeological history of the system, has shown that the driving process in the geochemical evolution of this groundwater system is the mixing between four end-member waters: a deep and old saline water, a glacial meltwater, an old marine water, and a meteoric water. In this paper we put the focus on mixing and its effects on the final chemical composition of the groundwaters using a comprehensive methodology that combines principal component analysis with mass balance calculations. This methodology allows us to test several combinations of end member waters and several combinations of compositional variables in order to find optimal solutions in terms of mixing proportions. We have applied this methodology to a dataset of 287 groundwater samples from the Laxemar area collected and analysed by SKB. The best model found uses four conservative elements (Cl, Br, oxygen-18 and deuterium), and computes mixing proportions with respect to three end member waters (saline, glacial and meteoric). Once the first order effect of mixing has been taken into account, water-rock interaction can be used to explain the remaining variability. In this way, the chemistry of each water sample can be obtained by using the mixing proportions for the conservative elements, only affected by mixing, or combining the mixing proportions and the chemical reactions for the non-conservative elements in the system, establishing the basis for predictive calculations. PMID:24070873

  14. Mineralogical characterization of selected shales in support of nuclear waste repository studies: Progress report, October 1987--September 1988

    SciTech Connect

    Lee, S. Y.; Hyder, L. K.; Baxter, P. M.

    1989-07-01

    One objective of the Sedimentary Rock Program at the Oak Ridge National Laboratory has been to examine end-member shales to develop a data base that will aid in evaluations if shales are ever considered as a repository host rock. Five end-member shales were selected for comprehensive characterization: the Chattanooga Shale from Fentress County, Tennessee; the Pierre Shale from Gregory County, South Dakota; the Green River Formation from Garfield County, Colorado; and the Nolichucky Shale and Pumpkin Valley Shale from Roane County, Tennessee. Detailed micromorphological and mineralogical characterizations of the shales were completed by Lee et al. (1987) in ORNL/TM-10567. This report is a supplemental characterization study that was necessary because second batches of the shale samples were needed for additional studies. Selected physical, chemical, and mineralogical properties were determined for the second batches; and their properties were compared with the results from the first batches. Physical characterization indicated that the second-batch and first-batch samples had a noticeable difference in apparent-size distributions but had similar primary-particle-size distributions. There were some differences in chemical composition between the batches, but these differences were not considered important in comparison with the differences among the end-member shales. The results of x-ray diffraction analyses showed that the second batches had mineralogical compositions very similar to the first batches. 9 refs., 9 figs., 4 tabs.

  15. The hydrothermal stability of cement sealing materials in the potential Yucca Mountain high level nuclear waste repository

    SciTech Connect

    Krumhansl, J.L.; Hinkebein, T.E.; Myers, J.

    1991-11-26

    Cementitious materials, together with other materials, are being considered to seal a potential repository at Yucca Mountain. A concern with cementitious materials is the chemical and mineralogic changes that may occur as these materials age while in contact with local ground waters. A combined theoretical and experimental approach was taken to determine the ability to theoretically predict mineralogic changes. The cementitious material selected for study has a relatively low Ca:Si ratio approaching that of the mineral tobermorite. Samples were treated hydrothermally at 200{degrees}C with water similar to that obtained from the J-13 well on the Nevada Test Site. Post-test solutions were analyzed for pH as well as dissolved K, Na, Ca, Al, and Si. Solid phases formed during these experiments were characterized by scanning electron microscopy and X- ray diffraction. These findings were compared with predictions made by the geochemical modeling code EQ3NR/E06. It was generally found that there was good agreement between predicted and experimental results.

  16. Systems study of the feasibility of high-level nuclear waste fractionation for thermal stress control in a geologic repository: appendices

    SciTech Connect

    McKee, R.W.; Elder, H.K.; McCallum, R.F.; Silviera, D.J.; Swanson, J.L.; Wiles, L.E.

    1983-06-01

    This study assesses the benefits and costs of fractionating the cesium and strontium (Cs/Sr) components in commercial high-level waste (HLW) to a separate waste stream for the purpose of reducing geologic-repository thermal stresses in the region of the HLW. The major conclusion is that the Cs/Sr fractionation concept offers the prospect of a substantial total system cost advantage for HLW disposal if reduced HLW package temperatures in a basalt repository are desired. However there is no cost advantage if currently designated maximum design temperatures are acceptable. Aging the HLW for 50 to 100 years can accomplish similar results at equivalent or lower costs. Volume II contains appendices for: (1) thermal analysis supplement; (2) fractionation process experimental results supplement; (3) cost analysis supplement; and (4) radiological risk analysis supplement.

  17. Nuclear waste programs; Semiannual progress report, October 1991--March 1992

    SciTech Connect

    Bates, J.K.; Bradley, C.R.; Buck, E.C.; Dietz, N.L.; Ebert, W.L.; Emery, J.W.; Feng, X.; Finn, P.A.; Gerding, T.J.; Hoh, J.C.

    1993-11-01

    This document reports on the work done by the Nuclear Waste Programs of the Chemical Technology Division (CMT), Argonne National Laboratory, in the period October 1991-March 1992. In these programs, studies are underway on the performance of waste glass and spent fuel in projected nuclear repository conditions to provide input to the licensing of the nation`s high-level waste repositories

  18. Nuclear Waste Programs semiannual progress report, April--September 1992

    SciTech Connect

    Bates, J.K.; Bradley, C.R.; Buck, E.C.

    1994-05-01

    This document reports on the work done by the Nuclear Waste Programs of the Chemical Technology Division (CMT), Argonne National Laboratory, in the period April--September 1992. In these programs, studies are underway on the performance of waste glass and spent fuel in projected nuclear repository conditions to provide input to the licensing of the nation`s high-level waste repositories.

  19. Swedish nuclear waste efforts

    SciTech Connect

    Rydberg, J.

    1981-09-01

    After the introduction of a law prohibiting the start-up of any new nuclear power plant until the utility had shown that the waste produced by the plant could be taken care of in an absolutely safe way, the Swedish nuclear utilities in December 1976 embarked on the Nuclear Fuel Safety Project, which in November 1977 presented a first report, Handling of Spent Nuclear Fuel and Final Storage of Vitrified Waste (KBS-I), and in November 1978 a second report, Handling and Final Storage of Unreprocessed Spent Nuclear Fuel (KBS II). These summary reports were supported by 120 technical reports prepared by 450 experts. The project engaged 70 private and governmental institutions at a total cost of US $15 million. The KBS-I and KBS-II reports are summarized in this document, as are also continued waste research efforts carried out by KBS, SKBF, PRAV, ASEA and other Swedish organizations. The KBS reports describe all steps (except reprocessing) in handling chain from removal from a reactor of spent fuel elements until their radioactive waste products are finally disposed of, in canisters, in an underground granite depository. The KBS concept relies on engineered multibarrier systems in combination with final storage in thoroughly investigated stable geologic formations. This report also briefly describes other activities carried out by the nuclear industry, namely, the construction of a central storage facility for spent fuel elements (to be in operation by 1985), a repository for reactor waste (to be in operation by 1988), and an intermediate storage facility for vitrified high-level waste (to be in operation by 1990). The R and D activities are updated to September 1981.

  20. Proposed methodology for completion of scenario analysis for the Basalt Waste Isolation Project. [Assessment of post-closure performance for a proposed repository for high-level nuclear waste

    SciTech Connect

    Roberds, W.J.; Plum, R.J.; Visca, P.J.

    1984-11-01

    This report presents the methodology to complete an assessment of postclosure performance, considering all credible scenarios, including the nominal case, for a proposed repository for high-level nuclear waste at the Hanford Site, Washington State. The methodology consists of defensible techniques for identifying and screening scenarios, and for then assessing the risks associated with each. The results of the scenario analysis are used to comprehensively determine system performance and/or risk for evaluation of compliance with postclosure performance criteria (10 CFR 60 and 40 CFR 191). In addition to describing the proposed methodology, this report reviews available methodologies for scenario analysis, discusses pertinent performance assessment and uncertainty concepts, advises how to implement the methodology (including the organizational requirements and a description of tasks) and recommends how to use the methodology in guiding future site characterization, analysis, and engineered subsystem design work. 36 refs., 24 figs., 1 tab.

  1. Evaluation of tuff as a medium for a nuclear waste repository: interim status report on the properties of tuff

    SciTech Connect

    Johnstone, J.K.; Wolfsberg, K.

    1980-07-01

    This report is the second in a series of summary briefings to the National Academy of Science`s (NAS) Committee on Radioactive Waste Management dealing with feasibility of disposal of heat-producing radioactive waste in silicic tuff. The interim status of studies of tuff properties determined on samples obtained from Yucca Mountain and Rainier Mesa (G-tunnel) located on the Nevada Test Site (NTS) are discussed. In particular, progress is described on resolving issues identified during the first briefing to the NAS which include behavior of water in tuff when heated, the effect of the presence or absence of water and joints on the thermal/physical properties of tuff and the detailed/complex sorptive properties of highly altered and unaltered tuff. Initial correlations of thermal/physical and sorptive properties with the highly variable porosity and mineralogy are described. Three in-situ, at-depth field experiments, one nearly completed and two just getting underway are described. In particular, the current status of mineralogy and petrology, geochemistry, thermal and mechanical, radiation effects and water behavior studies are described. The goals and initial results of a Mine Design Working Group are discussed. Regional factors such as seismicity, volcanism and hydrology are not discussed.

  2. A federalist strategy for nuclear waste management.

    PubMed

    Lee, K N

    1980-05-16

    The federal government plans to rely on a policy of "consultation and concurrence" with state governments in developing nuclear waste repositories. The weaknesses of the concurrence approach are analyzed, and an alternative institutional framework for locating a waste repository is proposed: a siting jury that provides representation for state and local interests, while maintaining a high level of technical review. The proposal could be tested in the siting of away-from-reactor storage facilities for spent nuclear fuel.

  3. Radiation-Induced Defects in Kaolinite as Tracers of Past Occurrence of Radionuclides in a Natural Analogue of High Level Nuclear Waste Repository

    NASA Astrophysics Data System (ADS)

    Allard, T.; Fourdrin, C.; Calas, G.

    2007-05-01

    Understanding the processes controlling migrations of radioelements at the Earth's surface is an important issue for the long-term safety assessment of high level nuclear waste repositories (HLNWR). Evidence of past occurrence and transfer of radionuclides can be found using radiation-induced defects in minerals. Clay minerals are particularly relevant because of their widespread occurrence at the Earth's surface and their finely divided nature which provides high contact area with radioactive fluids. Owing to its sensitivity to radiations, kaolinite can be used as natural, in situ dosimeter. Kaolinite is known to contain radiation-induced defects which are detected by Electron Paramagnetic Resonance. They are differentiated by their nature, their production kinetics and their thermal stability. One of these defects is stable at the scale of geological periods and provides a record of past radionuclide occurrence. Based on artificial irradiations, a methodology has been subsequently proposed to determine paleodose cumulated by kaolinite since its formation. The paleodose can be used to derive equivalent radioelement concentrations, provided that the age of kaolinite formation can be constrained. This allows quantitative reconstruction of past transfers of radioelements in natural systems. An example is given for the Nopal I U-deposit (Chihuahua, Mexico), hosted in hydrothermally altered volcanic tufs and considered as analogue of the Yucca Mountain site. The paleodoses experienced by kaolinites were determined from the concentration of defects and dosimetry parameters of experimental irradiations. Using few geochemical assumption, a equivalent U-content responsible for defects in kaolinite was calculated from the paleodose, a dose rate balance and model ages of kaolinites constrained by tectonic phases. In a former study, the ages were assumptions derived from regional tectonic events. In thepresent study, ages of mineralization events are measured from U

  4. Can Indigenous and Introduced Bacteria Affect the Performance of an Engineered Barrier System in the Designated Yucca Mountain Nuclear Waste Repository?

    NASA Astrophysics Data System (ADS)

    Martin, S.; Dias, V.; Carrillo, C.; van Buuren, N.; Horn, J.

    2002-12-01

    The U.S. Department of Energy has been tasked with establishing a high level nuclear waste repository at Yucca Mountain, NV and assessing the effects of long-term storage of the waste. Studies are being performed to identify the role of microorganisms, both indigenous and introduced during the construction phase, to waste package material corrosion. Some microorganisms produce by-products that may be deleterious to waste package materials, such as bacteria that produce hydrogen and mineral acids, or reduce sulfate, and fungi that produce organic acids. Long-term and accelerated tests in continuous flow reactors were conducted to assess the biogenic effects on waste package materials, and batch tests were implemented to identify corrosion products and biochemical changes to ground water chemistry. Surfacial and gravimetric analyses of the metal samples coupled with water chemistry analysis allow us to determine the overall contribution that organisms may make to waste package corrosion. Metal samples were periodically removed from the reactors and examined with scanning electron and atomic force microscopy. Effluent samples were also collected and analyzed using inductively coupled plasma spectroscopy-mass spectrometry and ion chromatography. Sterile controls were run in parallel to understand abiotic contributions to metals corrosion. In addition, we have characterized the microbial community at Yucca Mountain in order to define the physiological potential of the organisms extant at the site and evaluate the conditions required for growth (we have determined that water availability will be the major limiting factor). Analysis of the fluids from batch tests containing the Alloy 22 (Ni-Cr-Mo alloy) metal suggest the solubilization of Mo, albeit in very low concentrations. Because we did not observe the solubilization of other metal components, it is unclear whether selective solubilization or dealloying is occurring. Endpoint analysis of precipitated particles in the

  5. Milestones for Selection Characterization and Analysis of the Performance of a Repository for Spent Nuclear Fuel and HIh-Level Radioactive Waste at Yucca Mountain.

    SciTech Connect

    Rechard, Robert P.

    2015-02-01

    This report presents a concise history in tabular form of events leading up to site identification in 1978, site selection in 1987, subsequent characterization, and ongoing analysis throu gh 2009 of the performance of a repository for spent nuclear fuel and high - level radi oactive waste at Yucca Mou ntain in southern Nevada. The tabulated events generally occurred in five periods: (1) commitment to mined geologic disposal and identification of sites; (2) site selection and analysis, based on regional geologic characterization through literature and an alogous data; (3) feasibility analysis demonstrating calculation procedures and importance of system components, based on rough measures of performance using surface exploration, waste process knowledge, and general laboratory experiments; (4) suitability analysis demonstrating viability of disposal system, based on environment - specific laboratory experiments, in - situ experiments, and underground disposal system characterization; and (5) compliance analysis, based on completed site - specific characterization . The current sixth period beyond 2010 represents a new effort to set waste management policy in the United States. Because the relationship is important to understanding the evolution of the Yucca Mountain Project , the tabulation also shows the interaction between the policy realm and technical realm using four broad categories of events : (a ) R egulatory requirements and related federal policy in laws and court decisions, (c ) Presidential and agency directives, (c) technical milestones of implemen ting institutions, and (d ) critiques of the Yucca Mountai n P roject and pertinent national and world events related to nuclear energy and radioactive waste. Preface The historical progression of technical milestones for the Yucca Mountain Project was originally developed for 10 journal articles in a special issue of Reliability Engineering System Safe ty on the performance assessment for the Yucca Mountain

  6. Case for retrievable high-level nuclear waste disposal

    USGS Publications Warehouse

    Roseboom, Eugene H.

    1994-01-01

    Plans for the nation's first high-level nuclear waste repository have called for permanently closing and sealing the repository soon after it is filled. However, the hydrologic environment of the proposed site at Yucca Mountain, Nevada, should allow the repository to be kept open and the waste retrievable indefinitely. This would allow direct monitoring of the repository and maintain the options for future generations to improve upon the disposal methods or use the uranium in the spent fuel as an energy resource.

  7. Characteristics of potential repository wastes. Volume 1

    SciTech Connect

    Not Available

    1992-07-01

    This document, and its associated appendices and microcomputer (PC) data bases, constitutes the reference OCRWM data base of physical and radiological characteristics data of radioactive wastes. This Characteristics Data Base (CDB) system includes data on spent nuclear fuel and high-level waste (HLW), which clearly require geologic disposal, and other wastes which may require long-term isolation, such as sealed radioisotope sources. The data base system was developed for OCRWM by the CDB Project at Oak Ridge National Laboratory. Various principal or official sources of these data provided primary information to the CDB Project which then used the ORIGEN2 computer code to calculate radiological properties. The data have been qualified by an OCRWM-sponsored peer review as suitable for quality-affecting work meeting the requirements of OCRWM`s Quality Assurance Program. The wastes characterized in this report include: light-water reactor (LWR) spent fuel and immobilized HLW.

  8. Groundwater flow modeling of periods with periglacial and glacial climate conditions for the safety assessment of the proposed high-level nuclear waste repository site at Forsmark, Sweden

    NASA Astrophysics Data System (ADS)

    Vidstrand, Patrik; Follin, Sven; Selroos, Jan-Olof; Näslund, Jens-Ove

    2014-09-01

    The impact of periglacial and glacial climate conditions on groundwater flow in fractured crystalline rock is studied by means of groundwater flow modeling of the Forsmark site, which was recently proposed as a repository site for the disposal of spent high-level nuclear fuel in Sweden. The employed model uses a thermal-hydraulically coupled approach for permafrost modeling and discusses changes in groundwater flow implied by the climate conditions found over northern Europe at different times during the last glacial cycle (Weichselian glaciation). It is concluded that discharge of particles released at repository depth occurs very close to the ice-sheet margin in the absence of permafrost. If permafrost is included, the greater part discharges into taliks in the periglacial area. During a glacial cycle, hydraulic gradients at repository depth reach their maximum values when the ice-sheet margin passes over the site; at this time, also, the interface between fresh and saline waters is distorted the most. The combined effect of advances and retreats during several glaciations has not been studied in the present work; however, the results indicate that hydrochemical conditions at depth in the groundwater flow model are almost restored after a single event of ice-sheet advance and retreat.

  9. For Sale: Nuclear Waste Sites--Anyone Buying?

    ERIC Educational Resources Information Center

    Hancock, Don

    1992-01-01

    Explores why the United States Nuclear Waste Program has been unable to find a volunteer state to host either a nuclear waste repository or monitored retrieval storage facility. Discusses the Department of Energy's plans for Nevada's Yucca Mountain as a repository and state and tribal responses to the plan. (21 references) (MCO)

  10. Waste package/repository impact study: Final report

    SciTech Connect

    Not Available

    1985-09-01

    The Waste Package/Repository Impact Study was conducted to evaluate the feasibility of using the current reference salt waste package in the salt repository conceptual design. All elements of the repository that may impact waste package parameters, i.e., (size, weight, heat load) were evaluated. The repository elements considered included waste hoist feasibility, transporter and emplacement machine feasibility, subsurface entry dimensions, feasibility of emplacement configuration, and temperature limits. The evaluations are discussed in detail with supplemental technical data included in Appendices to this report, as appropriate. Results and conclusions of the evaluations are discussed in light of the acceptability of the current reference waste package as the basis for salt conceptual design. Finally, recommendations are made relative to the salt project position on the application of the reference waste package as a basis for future design activities. 31 refs., 11 figs., 11 tabs.

  11. Characteristics of potential repository wastes. Volume 2

    SciTech Connect

    Not Available

    1992-07-01

    The LWR spent fuels discussed in Volume 1 of this report comprise about 99% of all domestic non-reprocessed spent fuel. In this report we discuss other types of spent fuels which, although small in relative quantity, consist of a number of diverse types, sizes, and compositions. Many of these fuels are candidates for repository disposal. Some non-LWR spent fuels are currently reprocessed or are scheduled for reprocessing in DOE facilities at the Savannah River Site, Hanford Site, and the Idaho National Engineering Laboratory. It appears likely that the reprocessing of fuels that have been reprocessed in the past will continue and that the resulting high-level wastes will become part of defense HLW. However, it is not entirely clear in some cases whether a given fuel will be reprocessed, especially in cases where pretreatment may be needed before reprocessing, or where the enrichment is not high enough to make reprocessing attractive. Some fuels may be canistered, while others may require special means of disposal. The major categories covered in this chapter include HTGR spent fuel from the Fort St. Vrain and Peach Bottom-1 reactors, research and test reactor fuels, and miscellaneous fuels, and wastes generated from the decommissioning of facilities.

  12. A performance goal-based seismic design philosophy for waste repository facilities

    SciTech Connect

    Hossain, Q.A.

    1994-02-01

    A performance goal-based seismic design philosophy, compatible with DOE`s present natural phenomena hazards mitigation and ``graded approach`` philosophy, has been proposed for high level nuclear waste repository facilities. The rationale, evolution, and the desirable features of this method have been described. Why and how the method should and can be applied to the design of a repository facility are also discussed.

  13. Numerical study of the THM effects on the near-field safety of ahypothetical nuclear waste repository - BMT1 of the DECOVALEX IIIproject. Part 3: Effects of THM coupling in sparsely fracturedrocks

    SciTech Connect

    Rutqvist, J.; Chijimatsu, M.; Jing, L.; Millard, A.; Nguyen,T.S.; Rejeb, A.; Sugita, Y.; Tsang, C.F.

    2004-09-09

    BENCHPAR project, the impact of thermal-hydrological-mechanical (THM) couplings on the performance of a bentonite-back-filled nuclear waste repository in near-field crystalline rocks is evaluated in a Bench-Mark Test problem (BMT1) and the results are presented in a series of three companion papers in this issue. This is the third paper with focus on the effects of THM processes at a repository located in a sparsely fractured rock. Several independent coupled THM analyses presented in this paper show that THM couplings have the most significant impact on the mechanical stress evolution, which is important for repository design, construction and post-closure monitoring considerations. The results show that the stress evolution in the bentonite-back-filled excavations and the surrounding rock depends on the post-closure evolution of both fields of temperature and fluid pressure.It is further shown that the time required to full resaturation may play an important role for the mechanical integrity of the repository drifts.In this sense, the presence of hydraulically conducting fractures in the near-field rock might actually improve the mechanical performance of the repository. Hydraulically conducting fractures in the near-field rocks enhances the water supply to the buffers/back-fills, which promotes a more timely process of resaturation and development of swelling pressures in the back-fill, thus provides timely confining stress and support to the rock walls. In one particular case simulated in this study, it was shown that failure in the drift walls could be prevented if the compressive stresses in back-fill were fully developed within 50 years,which is when thermally induced rock strain begins to create high differential (failure-prone) stresses in the near-field rocks.

  14. Alternative configurations for the waste-handling building at the Yucca Mountain Repository

    SciTech Connect

    1990-08-01

    Two alternative configurations of the waste-handling building have been developed for the proposed nuclear waste repository in tuff at Yucca Mountain, Nevada. One configuration is based on criteria and assumptions used in Case 2 (no monitored retrievable storage facility, no consolidation), and the other configuration is based on criteria and assumptions used in Case 5 (consolidation at the monitored retrievable storage facility) of the Monitored Retrievable Storage System Study for the Repository. Desirable waste-handling design concepts have been selected and are included in these configurations. For each configuration, general arrangement drawings, plot plans, block flow diagrams, and timeline diagrams are prepared.

  15. Nuclear waste disposal: Gambling on Yucca Mountain

    SciTech Connect

    Ginsburg, S.

    1995-05-01

    This document describes the historical aspects of nuclear energy ,nuclear weapons usage, and development of the nuclear bureaucracy in the United States, and discusses the selection and siting of Yucca Mountain, Nevada for a federal nuclear waste repository. Litigation regarding the site selection and resulting battles in the political arena and in the Nevada State Legislature are also presented. Alternative radioactive waste disposal options, risk assessments of the Yucca Mountain site, and logistics regarding the transportation and storage of nuclear waste are also presented. This document also contains an extensive bibliography.

  16. Building of multilevel stakeholder consensus in radioactive waste repository siting

    SciTech Connect

    Dreimanis, A.

    2007-07-01

    This report considers the problem of multilevel consensus building for siting and construction of shared multinational/regional repositories for radioactive waste (RW) deep disposal. In the siting of a multinational repository there appears an essential innovative component of stakeholder consensus building, namely: to reach consent - political, social, economic, ecological - among international partners, in addition to solving the whole set of intra-national consensus building items. An entire partnering country is considered as a higher-level stakeholder - the national stakeholder, represented by the national government, being faced to simultaneous seeking an upward (international) and a downward (intra-national) consensus in a psychologically stressed environment, possibly being characterized by diverse political, economic and social interests. The following theses as a possible interdisciplinary approach towards building of shared understanding and stakeholder consensus on the international scale of RW disposal are forwarded and developed: a) building of international stakeholder consensus would be promoted by activating and diversifying on the international scale multilateral interactions between intra- and international stakeholders, including web-based networks of the RW disposal site investigations and decision-making, as well as networks for international cooperation among government authorities in nuclear safety, b) gradual progress in intergovernmental consensus and reaching multilateral agreements on shared deep repositories will be the result of democratic dialogue, via observing the whole set of various interests and common resolving of emerged controversies by using advanced synergetic approaches of conflict resolution, c) cross-cultural thinking and world perception, mental flexibility, creativity and knowledge are considered as basic prerogatives for gaining a higher level of mutual understanding and consensus for seeking further consensus, for

  17. Public reactions to nuclear waste

    SciTech Connect

    Dunlap, R.E.; Kraft, M.E.; Rosa, E.A.

    1993-12-31

    For many scientists, engineers, and regulators, the public controversy over siting a repository for high-level nuclear wastes exemplifies the clash between rational scientific judgment and irrational public attitudes. Even many who are more sympathetic to public concerns about risk and management believe the controversy is exacerbated by incompatibilities between good science and public participation in regulatory decision-making. Understanding the incompatibilities, however, is crucial to managing science and technology in a democratic society and provides an important motivation to study the relationship between public opinion and nuclear waste policy. In this book, Dunlap and his colleagues present a solid base of empirical research on the subject, and the strength of the collection is the careful unraveling of social factors and context to explain the overwhelmingly negative public view of nuclear waste and its management.

  18. Assessing microbiologically induced corrosion of waste package materials in the Yucca Mountain repository

    SciTech Connect

    Horn, J. M., LLNL

    1998-01-01

    The contribution of bacterial activities to corrosion of nuclear waste package materials must be determined to predict the adequacy of containment for a potential nuclear waste repository at Yucca Mountain (YM), NV. The program to evaluate potential microbially induced corrosion (MIC) of candidate waste container materials includes characterization of bacteria in the post-construction YM environment, determination of their required growth conditions and growth rates, quantitative assessment of the biochemical contribution to metal corrosion, and evaluation of overall MIC rates on candidate waste package materials.

  19. Thermal - Hydraulic Behavior of Unsaturated Bentonite and Sand-Bentonite Material as Seal for Nuclear Waste Repository: Numerical Simulation of Column Experiments

    NASA Astrophysics Data System (ADS)

    Ballarini, E.; Graupner, B.; Bauer, S.

    2015-12-01

    For deep geological repositories of high-level radioactive waste (HLRW), bentonite and sand bentonite mixtures are investigated as buffer materials to form a a sealing layer. This sealing layer surrounds the canisters and experiences an initial drying due to the heat produced by HLRW and a successive re-saturation with fluid from the host rock. These complex thermal, hydraulic and mechanical processes interact and were investigated in laboratory column experiments using MX-80 clay pellets as well as a mixture of 35% sand and 65% bentonite. The aim of this study is to both understand the individual processes taking place in the buffer materials and to identify the key physical parameters that determine the material behavior under heating and hydrating conditions. For this end, detailed and process-oriented numerical modelling was applied to the experiments, simulating heat transport, multiphase flow and mechanical effects from swelling. For both columns, the same set of parameters was assigned to the experimental set-up (i.e. insulation, heater and hydration system), while the parameters of the buffer material were adapted during model calibration. A good fit between model results and data was achieved for temperature, relative humidity, water intake and swelling pressure, thus explaining the material behavior. The key variables identified by the model are the permeability and relative permeability, the water retention curve and the thermal conductivity of the buffer material. The different hydraulic and thermal behavior of the two buffer materials observed in the laboratory observations was well reproduced by the numerical model.

  20. Potential role of ABC-assisted repositories in U.S. plutonium and high-level waste disposition

    NASA Astrophysics Data System (ADS)

    Berwald, David; Favale, Anthony; Myers, Timothy; McDaniel, Jerry

    1995-09-01

    This paper characterizes the issues involving deep geologic disposal of LWR spent fuel rods, then presents results of an investigation to quantify the potential role of Accelerator-Based Conversion (ABC) in an integrated national nuclear materials and high level waste disposition strategy. The investigation used the deep geological repository envisioned for Yucca Mt., Nevada as a baseline and considered complementary roles for integrated ABC transmutation systems. The results indicate that although a U.S. geologic waste repository will continue to be required, waste partitioning and accelerator transmutation of plutonium, the minor actinides, and selected long-lived fission products can result in the following substantial benefits: plutonium burndown to near zero levels, a dramatic reduction of the long term hazard associated with geologic repositories, an ability to place several-fold more high level nuclear waste in a single repository, electricity sales to compensate for capital and operating costs.

  1. Potential role of ABC-assisted repositories in U.S. plutonium and high-level waste disposition

    SciTech Connect

    Berwald, David; Favale, Anthony; Myers, Timothy; McDaniel, Jerry

    1995-09-15

    This paper characterizes the issues involving deep geologic disposal of LWR spent fuel rods, then presents results of an investigation to quantify the potential role of Accelerator-Based Conversion (ABC) in an integrated national nuclear materials and high level waste disposition strategy. The investigation used the deep geological repository envisioned for Yucca Mt., Nevada as a baseline and considered complementary roles for integrated ABC transmutation systems. The results indicate that although a U.S. geologic waste repository will continue to be required, waste partitioning and accelerator transmutation of plutonium, the minor actinides, and selected long-lived fission products can result in the following substantial benefits: plutonium burndown to near zero levels, a dramatic reduction of the long term hazard associated with geologic repositories, an ability to place several-fold more high level nuclear waste in a single repository, electricity sales to compensate for capital and operating costs.

  2. Investigations of natural groundwater hazards at the proposed Yucca Mountain high level nuclear waste repository. Part A: Geology at Yucca Mountain. Part B: Modeling of hydro-tectonic phenomena relevant to Yucca Mountain. Annual report - Nevada

    SciTech Connect

    Szymanski, J.S.; Schluter, C.M.; Livingston, D.E.

    1993-05-01

    This document is an annual report describing investigations of natural groundwater hazards at the proposed Yucca Mountain, Nevada High-Level Nuclear Waste Repository.This document describes research studies of the origin of near surface calcite/silica deposits at Yucca Mountain. The origin of these deposits is controversial and the authors have extended and strengthened the basis of their arguments for epigenetic, metasomatic alteration of the tuffs at Yucca Mountain. This report includes stratigraphic, mineralogical, and geochronological information along with geochemical data to support the conclusions described by Livingston and Szymanski, and others. As part of their first annual report, they take this opportunity to clarify the technical basis of their concerns and summarize the critical geological field evidence and related information. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  3. Nuclear Waste Disposal

    SciTech Connect

    Gee, Glendon W.; Meyer, Philip D.; Ward, Andy L.

    2005-01-12

    Nuclear wastes are by-products of nuclear weapons production and nuclear power generation, plus residuals of radioactive materials used by industry, medicine, agriculture, and academia. Their distinctive nature and potential hazard make nuclear wastes not only the most dangerous waste ever created by mankind, but also one of the most controversial and regulated with respect to disposal. Nuclear waste issues, related to uncertainties in geologic disposal and long-term protection, combined with potential misuse by terrorist groups, have created uneasiness and fear in the general public and remain stumbling blocks for further development of a nuclear industry in a world that may soon be facing a global energy crisis.

  4. Radionuclide transport behavior in a generic geological radioactive waste repository.

    PubMed

    Bianchi, Marco; Liu, Hui-Hai; Birkholzer, Jens T

    2015-01-01

    We performed numerical simulations of groundwater flow and radionuclide transport to study the influence of several factors, including the ambient hydraulic gradient, groundwater pressure anomalies, and the properties of the excavation damaged zone (EDZ), on the prevailing transport mechanism (i.e., advection or molecular diffusion) in a generic nuclear waste repository within a clay-rich geological formation. By comparing simulation results, we show that the EDZ plays a major role as a preferential flowpath for radionuclide transport. When the EDZ is not taken into account, transport is dominated by molecular diffusion in almost the totality of the simulated domain, and transport velocity is about 40% slower. Modeling results also show that a reduction in hydraulic gradient leads to a greater predominance of diffusive transport, slowing down radionuclide transport by about 30% with respect to a scenario assuming a unit gradient. In addition, inward flow caused by negative pressure anomalies in the clay-rich formation further reduces transport velocity, enhancing the ability of the geological barrier to contain the radioactive waste. On the other hand, local high gradients associated with positive pressure anomalies can speed up radionuclide transport with respect to steady-state flow systems having the same regional hydraulic gradients. Transport behavior was also found to be sensitive to both geometrical and hydrogeological parameters of the EDZ. Results from this work can provide useful knowledge toward correctly assessing the post-closure safety of a geological disposal system. PMID:24571606

  5. Radionuclide transport behavior in a generic geological radioactive waste repository.

    PubMed

    Bianchi, Marco; Liu, Hui-Hai; Birkholzer, Jens T

    2015-01-01

    We performed numerical simulations of groundwater flow and radionuclide transport to study the influence of several factors, including the ambient hydraulic gradient, groundwater pressure anomalies, and the properties of the excavation damaged zone (EDZ), on the prevailing transport mechanism (i.e., advection or molecular diffusion) in a generic nuclear waste repository within a clay-rich geological formation. By comparing simulation results, we show that the EDZ plays a major role as a preferential flowpath for radionuclide transport. When the EDZ is not taken into account, transport is dominated by molecular diffusion in almost the totality of the simulated domain, and transport velocity is about 40% slower. Modeling results also show that a reduction in hydraulic gradient leads to a greater predominance of diffusive transport, slowing down radionuclide transport by about 30% with respect to a scenario assuming a unit gradient. In addition, inward flow caused by negative pressure anomalies in the clay-rich formation further reduces transport velocity, enhancing the ability of the geological barrier to contain the radioactive waste. On the other hand, local high gradients associated with positive pressure anomalies can speed up radionuclide transport with respect to steady-state flow systems having the same regional hydraulic gradients. Transport behavior was also found to be sensitive to both geometrical and hydrogeological parameters of the EDZ. Results from this work can provide useful knowledge toward correctly assessing the post-closure safety of a geological disposal system.

  6. Nuclear waste package fabricated from concrete

    SciTech Connect

    Pfeiffer, P.A.; Kennedy, J.M.

    1987-03-01

    After the United States enacted the Nuclear Waste Policy Act in 1983, the Department of Energy must design, site, build and operate permanent geologic repositories for high-level nuclear waste. The Department of Energy has recently selected three sites, one being the Hanford Site in the state of Washington. At this particular site, the repository will be located in basalt at a depth of approximately 3000 feet deep. The main concern of this site, is contamination of the groundwater by release of radionuclides from the waste package. The waste package basically has three components: the containment barrier (metal or concrete container, in this study concrete will be considered), the waste form, and other materials (such as packing material, emplacement hole liners, etc.). The containment barriers are the primary waste container structural materials and are intended to provide containment of the nuclear waste up to a thousand years after emplacement. After the containment barriers are breached by groundwater, the packing material (expanding sodium bentonite clay) is expected to provide the primary control of release of radionuclide into the immediate repository environment. The loading conditions on the concrete container (from emplacement to approximately 1000 years), will be twofold; (1) internal heat of the high-level waste which could be up to 400/sup 0/C; (2) external hydrostatic pressure up to 1300 psi after the seepage of groundwater has occurred in the emplacement tunnel. A suggested container is a hollow plain concrete cylinder with both ends capped. 7 refs.

  7. Economic implications of locating a nuclear waste repository in Texas. Hearing before the Subcommittee on Nuclear Regulation of the Committee on Environment and Public Works, United States Senate, Ninety-Ninth Congress, First Session, February 11, 1985, Hereford, TX

    SciTech Connect

    Not Available

    1985-01-01

    Ten witnesses representing Texas industries and agriculture spoke at a field hearing in Hereford, Texas on the selection of Deaf Smith County as one of the three potential repository sites for spent fuel and high-level radioactive wastes. Safety and the potential for ground water contamination were major arguments of the opponents to the location. DOE spokesman William Purcell advised that no material will be placed in the repository until the turn of the century and then after a lengthy public licensing procedure. Other concerns were the socio-economic impacts on the surrounding area and the possible damage to agriculture if either soil or water contamination should occur. Additional statements submitted for the record follow the testimony.

  8. Comparison of the Microbial Community Composition at Yucca Mountain and Laboratory Test Nuclear Repository Environments

    SciTech Connect

    Horn, J; Carrillo, C; Dias, V

    2002-10-09

    The microbiological community structure within a proposed nuclear waste repository at Yucca Mountain (YM), NV was determined. Microbial growth from collected rock was detected using simulated ground water as a growth medium, with or without amendment of a carbon source. Grown isolates were identified by 16s ribosomal DNA (rDNA) sequence analysis. A more complete compositional analysis of the microbial community located at the proposed nuclear waste repository site was performed using environmental DNA isolation and subsequent identification of amplified 16s rDNA genes. Concurrently, a series of corrosion testing tanks that simulate the evolution of anticipated environmental conditions within the proposed repository have been subjected to the same type of analyses.

  9. Thermodynamic Properties of Magnesium Chloride Hydroxide Hydrate (Mg3Cl(OH)5:4H2O, Phase 5), and Its importance to Nuclear Waste Isolation in Geological Repositories in Salt Formations

    NASA Astrophysics Data System (ADS)

    Xiong, Y.; Deng, H.; Nemer, M. B.; Johnsen, S.

    2009-12-01

    -1, respectively. Phase 5, and its similar phase, phase 3 (Mg2Cl(OH)3:4H2O), could have a significant role in influencing the geochemical conditions in geological repositories for nuclear waste in salt formations where MgO or brucite is employed as engineered barriers, when Na-Mg-Cl dominated brines react with MgO or brucite. Based on our solubility constant for phase 5 in combination with the literature value for phase 3, we predict that the composition for the invariant point of phase 5 and phase 3 would be mMg = 1.70 and pmH = 8.93 in the Mg-Cl binary system. The recent WIPP Compliance Recertification Application PA Baseline Calculations indicate that phase 5 instead of phase 3 is indeed a stable phase when GWB equilibrates with actinide-source-term phases, brucite, magnesium carbonates, halite and anhydrite. 1. This research is funded by WIPP programs administered by the U.S. Department of Energy. 2. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.

  10. Nuclear waste forms for actinides

    PubMed Central

    Ewing, Rodney C.

    1999-01-01

    The disposition of actinides, most recently 239Pu from dismantled nuclear weapons, requires effective containment of waste generated by the nuclear fuel cycle. Because actinides (e.g., 239Pu and 237Np) are long-lived, they have a major impact on risk assessments of geologic repositories. Thus, demonstrable, long-term chemical and mechanical durability are essential properties of waste forms for the immobilization of actinides. Mineralogic and geologic studies provide excellent candidate phases for immobilization and a unique database that cannot be duplicated by a purely materials science approach. The “mineralogic approach” is illustrated by a discussion of zircon as a phase for the immobilization of excess weapons plutonium. PMID:10097054

  11. Waterproofing and Strengthening Volcanic Tuff in Waste Repositories

    SciTech Connect

    Carter, E.E.; Carter, P.E.; Cooper, D.C.

    2008-07-01

    Waste repositories from surface trenches and shafts at Los Alamos to drilled tunnels at Yucca Mountain are being built in volcanic Tuff, a soft compacted material that is permeable to water and air. US Department of Energy documents on repository design identify the primary design goal of 'preventing water from reaching the waste canisters, dissolving the canisters and carrying the radioactive waste particles away from the repository'. Designers expect to achieve this by use of multiple barriers along with careful placement of the repository both well above the water table and well above the ground level in a mountain. Though repositories are located in areas that have a historically dry climate to minimize the impact of rainfall infiltration, global warming phenomena may have the potential to alter regional climate patterns - potentially leading to higher infiltration rates. Conventional methods of sealing fractures within volcanic tuff may not be sufficiently robust or long lived to isolate a repository shaft from water for the required duration. A new grouting technology based on molten wax shows significant promise for producing the kind of long term sealing performance required. Molten wax is capable of permeating a significant distance through volcanic tuff, as well as sealing fractures by permeation that is thermally dependent instead of chemically or time dependent. The wax wicks into and saturates tuff even if no fractures are present, but penetrates and fills only the heated area. Heated portions of the rock fill like a vessel. The taffy-like wax has been shown to waterproof the tuff, and significantly increase its resistance to fracture. This wax was used in 2004 for grouting of buried radioactive beryllium waste at the Idaho National Laboratory, chiefly to stop the water based corrosion reactions of the waste. The thermoplastic material contains no water and does not dry out or change with age. Recent studies indicate that this kind of wax material may

  12. Repository thermal response: A preliminary evaluation of the effects of modeled waste stream resolution

    SciTech Connect

    Ryder, E.E.; Dunn, E.

    1995-09-01

    One of the primary factors that influences our predictions of host-rock thermal response within a high level waste repository is how the waste stream`s represented in the models. In the context of thermal modeling, waste stream refers to an itemized listing of the type (pressurized-water or boiling-water reactor), age, burnup, and enrichment of the spent nuclear fuel assemblies entering the repository over the 25-year emplacement phase. The effect of package-by-package variations in spent fuel characteristics on predicted repository thermal response is the focus of this report. A three-year portion of the emplacement period was modeled using three approaches to waste stream resolution. The first assumes that each package type emplaced in a given year is adequately represented by average characteristics. For comparison, two models that explicitly account for each waste package`s individual characteristics were run; the first assuming a random selection of packages and the second an ordered approach aimed at locating the higher power output packages toward the center of the emplacement area. Results indicate that the explicit representation of packages results in hot and cold spots that could have performance assessment and design implications. Furthermore, questions are raised regarding the representativeness of average characteristics with respect to integrated energy output and the possible implications of a mass-based repository loading approach.

  13. Reliable predictions of waste performance in a geologic repository

    SciTech Connect

    Pigford, T.H.; Chambre, P.L.

    1985-08-01

    Establishing reliable estimates of long-term performance of a waste repository requires emphasis upon valid theories to predict performance. Predicting rates that radionuclides are released from waste packages cannot rest upon empirical extrapolations of laboratory leach data. Reliable predictions can be based on simple bounding theoretical models, such as solubility-limited bulk-flow, if the assumed parameters are reliably known or defensibly conservative. Wherever possible, performance analysis should proceed beyond simple bounding calculations to obtain more realistic - and usually more favorable - estimates of expected performance. Desire for greater realism must be balanced against increasing uncertainties in prediction and loss of reliability. Theoretical predictions of release rate based on mass-transfer analysis are bounding and the theory can be verified. Postulated repository analogues to simulate laboratory leach experiments introduce arbitrary and fictitious repository parameters and are shown not to agree with well-established theory. 34 refs., 3 figs., 2 tabs.

  14. Experimental determination of the solubility constant for magnesium chloride hydroxide hydrate (Mg 3Cl(OH) 5·4H 2O, phase 5) at room temperature, and its importance to nuclear waste isolation in geological repositories in salt formations

    NASA Astrophysics Data System (ADS)

    Xiong, Yongliang; Deng, Haoran; Nemer, Martin; Johnsen, Shelly

    2010-08-01

    In this study, the solubility constant of magnesium chloride hydroxide hydrate, Mg 3Cl(OH) 5·4H 2O, termed as phase 5, is determined from a series of solubility experiments in MgCl 2-NaCl solutions. The solubility constant in logarithmic units at 25 °C for the following reaction, MgCl(OH)·4HO+5H=3Mg+9HO(l)+Cl is calculated as 43.21 ± 0.33 (2 σ) based on the specific interaction theory (SIT) model for extrapolation to infinite dilution. The Gibbs free energy and enthalpy of formation for phase 5 at 25 °C are derived as -3384 ± 2 (2 σ) kJ mol -1 and -3896 ± 6 (2 σ) kJ mol -1, respectively. MgO (bulk, pure MgO corresponding to the mineral periclase) is the only engineered barrier certified by the Environmental Protection Agency (EPA) for emplacement in the Waste Isolation Pilot Plant (WIPP) in the US, and an Mg(OH) 2-based engineered barrier (bulk, pure Mg(OH) 2 corresponding to brucite) is to be employed in the Asse repository in Germany. Phase 5, and its similar phase, phase 3 (Mg 2Cl(OH) 3·4H 2O), could have a significant role in influencing the geochemical conditions in geological repositories for nuclear waste in salt formations where MgO or brucite is employed as engineered barriers. Based on our solubility constant for phase 5 in combination with the literature value for phase 3, we predict that the composition for the invariant point of phase 5 and phase 3 would be mMg = 1.70 and pmH = 8.94 in the Mg-Cl binary system. The recent WIPP Compliance Recertification Application Performance Assessment Baseline Calculations indicate that phase 5, instead of phase 3, is indeed a stable phase when the WIPP Generic Weep Brine (GWB), a Na-Mg-Cl-dominated brine associated with the Salado Formation, equilibrates with actinide-source-term phases, brucite, magnesium carbonates, halite and anhydrite. Therefore, phase 5 is important to the WIPP, and potentially important to other repositories in salt formations.

  15. Viability Assessment of a Repository at Yucca Mountain. Volume 2: Preliminary Design Concept for the Repository and Waste Package

    SciTech Connect

    1998-12-01

    This volume describes the major design features of the Monitored Geologic Repository. This document is not intended to provide an exhaustive, detailed description of the repository design. Rather, this document summarizes the major systems and primary elements of the design that are radiologically significant, and references the specific technical documents and design analyses wherein the details can be found. Not all portions of the design are at the same level of completeness. Highest priority has been given to assigning resources to advance the design of the Monitored Geologic Repository features that are important to radiological safety and/or waste isolation and for which there is no NRC licensing precedent. Those features that are important to radiological safety and/or waste isolation, but for which there is an NRC precedent, receive second priority. Systems and features that have no impact on radiological safety or waste isolation receive the lowest priority. This prioritization process, referred to as binning, is discussed in more detail in Section 2.3. Not every subject discussed in this volume is given equal treatment with regard to the level of detail provided. For example, less detail is provided for the surface facility design than for the subsurface and waste package designs. This different level of detail is intentional. Greater detail is provided for those functions, structures, systems, and components that play key roles with regard to protecting radiological health and safety and that are not common to existing nuclear facilities already licensed by NRC. A number of radiological subjects are not addressed in the VA, (e.g., environmental qualification of equipment). Environmental qualification of equipment and other radiological safety considerations will be addressed in the LA. Non-radiological safety considerations such as silica dust control and other occupational safety considerations are considered equally important but are not addressed in

  16. Nuclear wastes and public trust

    SciTech Connect

    Flynn, J.; Slovic, P. |

    1993-06-01

    Citing public fear and mistrust, strong opposition to the proposed Yucca Mountain repository site, and less-than-exemplary performance by the Department of Energy (DOE), two private researchers believe present high-level radioactive waste-disposal plans may have to be scrapped. Government and the nuclear industry may have to start over. Policy makers should seek to develop new relationships with communities and states where suitable disposal sites exist. These relationships may require that citizen groups and local institutions be given unprecedented authority in locating and operating such facilities. Contrary to popular impressions, there is still time to take a new approach. The US Nuclear Regulatory Commission says present on-site storage arrangements offer a safe alternative for 100 years or more. The sense of immediate crisis and cries for immediate solutions should be calmed and a more considered strategy brought to the public debate. For starters, the researchers propose that the problems of defense waste be separated from the problems of commercial waste. They also suggest that DOE be assigned responsibility for defense waste and a new agency be created to handle high-level commercial waste.

  17. Nuclear waste policy and politics

    SciTech Connect

    Carter, L.J.

    1989-12-31

    The nation`s nuclear waste problem began in 1955 but did not draw widespread public attention until the early 1970s. It was then that the old Atomic Energy commission got in trouble by prematurely designating a site in Lyons, Kansas, as its first nuclear waste repository. This and several other false starts, coupled with the growing environmental and anti-nuclear movements, thrust the issue to the forefront of national consciousness. in the meantime, growing quantities of waste were accumulating at nuclear power plants across the country, creating mounting pressure for action. Congress acted in 1982 and again in 1987. Its 1987 decision was decisive: stop the nationwide search for a disposal site, and focus all efforts on Yucca Mountain in Nevada. Despite the clear Congressional mandate, the program is again bogged down in controversy, internal conflicts, and bureaucracy. Its future depends on a solution to these problems. And the solution involves charting some new and innovative paths around political and technical mine fields.

  18. Nuclear waste management

    NASA Astrophysics Data System (ADS)

    Chikalla, T. D.; Powell, J. A.

    1981-09-01

    Reports and summaries are presented for the following: high-level waste process development; alternative waste forms; TMI zeolite vitrification demonstration program; nuclear waste materials characterization center; TRU waste immobilization; TRU waste decontamination; krypton implantation; thermal outgassing; iodine-129 fixation; NWVP off-gas analysis; monitoring and physical characterization of unsaturated zone transport; well-logging instrumentation development; verification instrument development; mobility of organic complexes of radionuclides in soils; handbook of methods to decrease the generation of low-level waste; waste management system studies; waste management safety studies; assessment of effectiveness of geologic isolation systems; waste/rock interactions technology program; high-level waste form preparation; development of backfill materials; development of structural engineered barriers; disposal charge analysis; and analysis of spent fuel policy implementation.

  19. OCRWM International Cooperation in Nuclear Waste Management

    SciTech Connect

    Jackson, R.; Levich, R.; Strahl, J.

    2002-02-27

    With the implementation of nuclear power as a major energy source, the United States is increasingly faced with the challenges of safely managing its inventory of spent nuclear materials. In 2002, with 438 nuclear power facilities generating electrical energy in 31 nations around the world, the management of radioactive material including spent nuclear fuel and high-level radioactive waste, is an international concern. Most of the world's nuclear nations maintain radioactive waste management programs and have generally accepted deep geologic repositories as the long-term solution for disposal of spent nuclear fuel and high-level radioactive waste. Similarly, the United States is evaluating the feasibility of deep geologic disposal at Yucca Mountain, Nevada. This project is directed by the U.S. Department of Energy's Office of Civilian Radioactive Waste Management (OCRWM), which has responsibility for managing the disposition of spent nuclear fuel produced by commercial nuclear power facilities along with U.S. government-owned spent nuclear fuel and high-level radioactive waste. Much of the world class science conducted through the OCRWM program was enhanced through collaboration with other nations and international organizations focused on resolving issues associated with the disposition of spent nuclear fuel and high-level radioactive waste.

  20. Waste Inventory for Near Surface Repository (NSR) - 13482

    SciTech Connect

    Vaidotas, Algirdas

    2013-07-01

    The main characteristics, physical, chemical as well as radiological of the waste intended to be disposed of in the planned NSR are described. This description is mainly based on the waste inventory investigations performed by the Ignalina Nuclear Power Plant (INPP). The four different waste streams to be disposed of in the NSR are described and investigated. (authors)

  1. Materials Characterization Center state-of-the-art report on corrosion data pertaining to metallic barriers for nuclear-waste repositories

    SciTech Connect

    Merz, M.D.

    1982-10-01

    A compilation of published corrosion data on metals that have been suggested as canisters and overpack materials is presented. The data were categorized according to the solutions used in testing and divided into two parts: high-ionic strength solutions (such as seawater and brine) and low-ionic-strength waters (such as basalt and tuff waters). This distinction was made primarily because of the general difference in aggressiveness of these solutions with respect to general corrosion. A considerable amount of data indicated that titanium alloys have acceptably low uniform corrosion rates in anticipated repository sites; the other possible corrosion failure modes for titanium alloys, such as stress corrosion cracking and delayed failure due to hydrogen, have not been sufficiently studied to make any similar conclusions about lifetime with respect to these particular degradation processes. Other data suggested that iron-base alloys are sufficiently resistant to corrosion in basalt and tuff waters, although the effects of radiation and radiation combined with elevated temperature have not been reported in enough detail to conclusively qualify iron-base alloys for any particular barrier thickness in regard to uniform corrosion rate. The effect of overpack size on corrosion rate has been given little attention. A review of long-term underground data indicated that temperature and accessibility to oxygen were too different for deep geologic repositories to make the underground corrosion data directly applicable. However, the characteristics of corrosion attack, statistical treatment of data, and kinetics of corrosion showed that corrosion proceeds in a systematic and predictable way.

  2. Modeling the impact of climate change in Germany with biosphere models for long-term safety assessment of nuclear waste repositories.

    PubMed

    Staudt, C; Semiochkina, N; Kaiser, J C; Pröhl, G

    2013-01-01

    Biosphere models are used to evaluate the exposure of populations to radionuclides from a deep geological repository. Since the time frame for assessments of long-time disposal safety is 1 million years, potential future climate changes need to be accounted for. Potential future climate conditions were defined for northern Germany according to model results from the BIOCLIM project. Nine present day reference climate regions were defined to cover those future climate conditions. A biosphere model was developed according to the BIOMASS methodology of the IAEA and model parameters were adjusted to the conditions at the reference climate regions. The model includes exposure pathways common to those reference climate regions in a stylized biosphere and relevant to the exposure of a hypothetical self-sustaining population at the site of potential radionuclide contamination from a deep geological repository. The end points of the model are Biosphere Dose Conversion factors (BDCF) for a range of radionuclides and scenarios normalized for a constant radionuclide concentration in near-surface groundwater. Model results suggest an increased exposure of in dry climate regions with a high impact of drinking water consumption rates and the amount of irrigation water used for agriculture.

  3. A methodology to constrain the parameters of a hydrogeological discrete fracture network model for sparsely fractured crystalline rock, exemplified by data from the proposed high-level nuclear waste repository site at Forsmark, Sweden

    NASA Astrophysics Data System (ADS)

    Follin, Sven; Hartley, Lee; Rhén, Ingvar; Jackson, Peter; Joyce, Steven; Roberts, David; Swift, Ben

    2014-03-01

    The large-scale geological structure of the crystalline rock at the proposed high-level nuclear waste repository site at Forsmark, Sweden, has been classified in terms of deformation zones of elevated fracture frequency. The rock between deformation zones was divided into fracture domains according to fracture frequency. A methodology to constrain the geometric and hydraulic parameters that define a discrete fracture network (DFN) model for each fracture domain is presented. The methodology is based on flow logging and down-hole imaging in cored boreholes in combination with DFN realizations, fracture connectivity analysis and pumping test simulations. The simulations suggest that a good match could be obtained for a power law size distribution where the value of the location parameter equals the borehole radius but with different values for the shape parameter, depending on fracture domain and fracture set. Fractures around 10-100 m in size are the ones that typically form the connected network, giving inflows in the simulations. The report also addresses the issue of up-scaling of DFN properties to equivalent continuous porous medium (ECPM) bulk flow properties. Comparisons with double-packer injection tests provide confidence that the derived DFN formulation of detailed flows within individual fractures is also suited to simulating mean bulk flow properties and their spatial variability.

  4. Comparative simulation study of coupled THM processes nearback-filled and open-drift nuclear waste repositories in Task D of theInternational DECOVALEX Project

    SciTech Connect

    Rutqvist, J.; Birkholzer, J.T.; Chijimatsu, M.; Kolditz, O.; Liu,Quan-Sheng; Oda, Y.; Wang, Wenqing; Zhang, Cheng-Yuan

    2006-05-10

    As part of the ongoing international DECOVALEX project, fourresearch teams used five different models to simulate coupled thermal,hydrological, and mechanical (THM) processes near underground wasteemplacement drifts. The simulations were conducted for two genericrepository types, one with open and the other with back-filled repositorydrifts, under higher and lower post-closure temperature, respectively. Inthe completed first model inception phase of the project, a goodagreement was achieved between the research teams in calculating THMresponses for both repository types, although some disagreement inhydrological responses are currently being resolved. Good agreement inthe basic thermal-mechanical responses was also achieved for bothrepository types, even though some teams used relatively simplifiedthermal-elastic heat-conduction models that neglect complex near-fieldthermal-hydrological processes. The good agreement between the complexand simplified process models indicates that the basic thermal-mechanicalresponses can be predicted with a relatively high confidencelevel.

  5. High level nuclear waste

    SciTech Connect

    Crandall, J L

    1980-01-01

    The DOE Division of Waste Products through a lead office at Savannah River is developing a program to immobilize all US high-level nuclear waste for terminal disposal. DOE high-level wastes include those at the Hanford Plant, the Idaho Chemical Processing Plant, and the Savannah River Plant. Commercial high-level wastes, for which DOE is also developing immobilization technology, include those at the Nuclear Fuel Services Plant and any future commercial fuels reprocessing plants. The first immobilization plant is to be the Defense Waste Processing Facility at Savannah River, scheduled for 1983 project submission to Congress and 1989 operation. Waste forms are still being selected for this plant. Borosilicate glass is currently the reference form, but alternate candidates include concretes, calcines, other glasses, ceramics, and matrix forms.

  6. Nuclear waste solutions

    DOEpatents

    Walker, Darrel D.; Ebra, Martha A.

    1987-01-01

    High efficiency removal of technetium values from a nuclear waste stream is achieved by addition to the waste stream of a precipitant contributing tetraphenylphosphonium cation, such that a substantial portion of the technetium values are precipitated as an insoluble pertechnetate salt.

  7. Corrosion Engineers and Nuclear Waste Disposition

    SciTech Connect

    Rebak, R B

    2006-07-13

    More and more articles appear in the press daily about the renaissance of nuclear energy. Even many former opponents of nuclear energy are now convinced that nuclear energy is more environmentally friendly than burning fossil fuels. Nuclear energy does not release carbon dioxide to the atmosphere and therefore does not contribute to the global warming problem. But nuclear energy produces spent fuel or nuclear waste. Spent fuel is radioactive and requires thousands of years of isolation from plants, animals and humans. Every country currently studying the option for disposing of high-level nuclear waste has selected deep geologic formations to be the primary barrier for accomplishing this isolation. It is postulated that by the very nature of these geological sites, they will contain the waste for long time, limiting the spread of radionuclides, for example, through water flow. The release of radionuclides to the environment can also be delayed by the construction of engineered barrier systems between the waste and the geologic formation. Corrosion engineers are participating in the design and the performance prediction of the engineered barriers. The principal engineered component in this multibarrier approach is the container for the waste. Beyond the metallic containers, other engineered barriers could be added to attenuate the impact of the emplacement environment on the containers. The containers will probably be concentric double walled vessels of dissimilar metals. Each vessel would have a specific function. For example, the inner container may be designed to shield radiation and provide structural support to facilitate the safe handling and emplacement operations. This inner container may be over-packed with a corrosion-resistant outer layer. The design of the different containers for nuclear waste would vary according to the nature of the geologic formation at the site of the repository. The most common host rocks for nuclear waste repositories in the world

  8. Nuclear waste: Status of DOE`s nuclear waste site characterization activities

    SciTech Connect

    1987-12-31

    Three potential nuclear waste repository sites have been selected to carry out characterization activities-the detailed geological testing to determine the suitability of each site as a repository. The sites are Hanford in south-central Washington State, Yucca Mountain in southern Nevada, and Deaf Smith in the Texas Panhandle. Two key issues affecting the total program are the estimations of the site characterization completion data and costs and DOE`s relationship with the Nuclear Regulatory Commission which has been limited and its relations with affected states and Indian tribes which continue to be difficult.

  9. Gas phase migration of C-14 through barrier materials applicable for use in a high-level nuclear waste repository located in tuff

    SciTech Connect

    Bauer, L.R.

    1988-12-31

    A study of the movement of {sup 14}CO{sub 2} through proposed barrier media has been conducted. Diffusion coefficients for crushed tuff, bentonite and a 90:10% by wt. mixture of crushed tuff and bentonite were measured for two diffusion lengths. The ability of {sup 14}CO{sub 2} to penetrate a microsilica-containing portland cement mortar proposed for repository use was also examined. The specimens were subjected to uniaxially-applied compressive loads prior to the diffusion tests to simulate the onset of environmentally-induced microcracks. Based on these experiments, the apparent diffusion coefficients for the soil-based media were as follows: crushed tuff, 1.73 {plus_minus} 0.26 {times} 10{sup {minus}2} cm{sup 2}/s; bentonite, 1.56 {plus_minus} 0.61 {times} 10{sup {minus}2}/s; and the crushed tuff/bentonite mixture, 1.77 {plus_minus} 0.13 {times} 10{sup {minus}2} cm{sup 2}/s. These values correspond roughly to breakthrough times of 5 and 10-15 min respectively for the 6.5- and 23-cm thicknesses studied. With respect to the mortar studies, the penetration of {sup 14}CO{sub 2} through 1-cm thick microfractured discs was, in all cases, limited to the upper 1 mm of the cement surfaces. Serial sampling of the diffusion cells and pH testing of the cement surfaces indicated that the {sup 14}CO{sub 2} was consumed by the reaction of CO{sub 2} with free Ca(OH){sub 2} in the cement to form calcite (CaCO{sub 3}). The formation of the calcite apparently acted as a chemical and/or physical barrier to {sup 14}CO{sub 2} migration. Only when a disc was completely fractured could significant penetration of {sup 14}CO{sub 2} be observed. These results may have implications for the ability of a repository to comply with the applicable regulatory release limits for C-14.

  10. Nuclear Waste--Physics and Policy

    NASA Astrophysics Data System (ADS)

    Ahearne, John H.

    1996-03-01

    Managing and disposing of radioactive waste are major policy and financial issues in the United States and many other countries. Low-level waste sites, once thought to be possible in many states, remain fixed at the few sites that have been operating for decades. High-level waste remains at former nuclear weapons facilities and at nuclear power plants, and the DOE estimates a repository is unlikely before 2010, at the earliest. Physics and chemistry issues relate to criticality, plutonium loading in glass, leach rates, and diffusion. The public policy issues concern non-proliferation, states' rights, stakeholder participation, and nuclear power. Cleaning up the legacy of cold war driven nuclear weapons production is estimated to cost at least $250 billion and take three-quarters of a century. Some possible steps towards resolution of these issues will be described.

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

    SciTech Connect

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

    1983-10-12

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

  12. Limits on the thermal energy release from radioactive wastes in a mined geologic repository

    SciTech Connect

    Scott, J.A.

    1983-03-01

    The theraml energy release of nuclear wastes is a major factor in the design of geologic repositories. Thermal limits need to be placed on various aspets of the geologic waste disposal system to avoid or retard the degradation of repository performance because of increased temperatures. The thermal limits in current use today are summarized in this report. These limits are placed in a hierarchial structure of thermal criteria consistent with the failure mechanism they are trying to prevent. The thermal criteria hierarchy is used to evaluate the thermal performance of a sample repository design. The design consists of disassembled BWR spent fuel, aged 10 years, close packed in a carbon steel canister with 15 cm of crushed salt backfill. The medium is bedded salt. The most-restrictive temperature for this design is the spent-fuel centerline temperature limit of 300/sup 0/C. A sensitivity study on the effects of additional cooling prior to disposal on repository thermal limits and design is performed.

  13. Room closure response to gas generation and mechanical strength of different waste forms in a bedded salt repository

    SciTech Connect

    Mendenhall, F.T.; Stone, C.M.

    1993-05-01

    Finite element calculations of the porosity history of a nuclear waste disposal room in a bedded salt formation have been completed. The analyses include an elastic/secondary creep model for the host halite and a nonlinear consolidation model for the crushed salt backfill. Separate gas generation and constitutive models were used for three distinct waste forms, (1) unaltered defense related CH-TRU waste, (2) shredded and cemented CH-TRU waste, and (3) incinerated and vitrified CH-TRU waste. Solutions were determined for a 2000 year time period starting from the decommissioning of the repository. The resulting room porosities varied from roughly 55% to less than 10%.

  14. Managing Nuclear Waste: Options Considered

    SciTech Connect

    DOE

    2002-05-02

    Starting in the 1950s, U.S. scientists began to research ways to manage highly radioactive materials accumulating at power plants and other sites nationwide. Long-term surface storage of these materials poses significant potential health, safety, and environmental risks. Scientists studied a broad range of options for managing spent nuclear fuel and high-level radioactive waste. The options included leaving it where it is, disposing of it in various ways, and making it safer through advanced technologies. International scientific consensus holds that these materials should eventually be disposed of deep underground in what is called a geologic repository. In a recent special report, the National Academy of Sciences summarized the various studies and emphasized that geologic disposal is ultimately necessary.

  15. Effects of resource activities upon repository siting and waste containment with reference to bedded salt

    SciTech Connect

    Ashby, J.; Rowe, J.

    1980-02-01

    The primary consideration for the suitability of a nuclear waste repository site is the overall ability of the repository to safely contain radioactive waste. This report is a discussion of the past, present, and future effects of resource activities on waste containment. Past and present resource activities which provide release pathways (i.e., leaky boreholes, adjacent mines) will receive initial evaluation during the early stages of any repository site study. However, other resource activities which may have subtle effects on containment (e.g., long-term pumping causing increased groundwater gradients, invasion of saline water causing lower retardation) and all potential future resource activities must also be considered during the site evaluation process. Resource activities will affect both the siting and the designing of repositories. Ideally, sites should be located in areas of low resource activity and low potential for future activity, and repository design should seek to eliminate or minimize the adverse effects of any resource activity. Buffer zones should be created to provide areas in which resource activities that might adversely affect containment can be restricted or curtailed. This could mean removing large areas of land from resource development. The impact of these frozen assets should be assessed in terms of their economic value and of their effect upon resource reserves. This step could require a major effort in data acquisition and analysis followed by extensive numerical modeling of regional fluid flow and mass transport. Numerical models should be used to assess the effects of resource activity upon containment and should include the cumulative effects of different resource activities. Analysis by other methods is probably not possible except for relatively simple cases.

  16. Prediction of release rates for a potential waste repository at Yucca Mountain

    SciTech Connect

    Sadeghi, M.M.; Pigford, T.H.; Chambre, P.L.; Lee, W.W.L.

    1990-10-01

    Nuclear waste may be placed in the potential repository at Yucca Mountain in waste packages. The waste will consist of spent fuel assemblies or consolidated fuel rods, as well as borosilicate glass in steel pour containers, each enclosed in sealed containers. Current design calls for the waste packages to be surrounded by an air gap. Although the waste package is generally not seen as the primary barrier for nuclear waste isolation, it must in fact meet specific regulatory requirements. The US Nuclear Regulatory Commission requires that the release rate of any radionuclide from the engineered barrier system following the containment period shall not exceed one part in 100,000 per year of the inventory of that radionuclide calculated to be present at 1000 years following permanent closure. For low-inventory radionuclides, those that constitute less than 0.1 percent of the calculated total curie inventory at 1000 years, the allowable annual release is a constant value, equal to 10{sup {minus}8} of the total curie inventory in the repository at 1000 years. Therefore it is necessary to calculate release rates for waste packages at Yucca Mountain. We calculate release rates for key radionuclides using analytic solutions presented in a companion report. We consider both wet-drip and moist- continuous water-contact modes. We consider the release three types of species: solubility-limited species, species released congruent with solid-solid alteration of spent-fuel matrix or borosilicate glass, and readily soluble species from the fuel-cladding gap, gas plenum, and readily accessible grain boundaries. In each case we give the release rates of the species as a function of time. 22 refs., 11 figs., 9 tabs.

  17. Can shale safely host US nuclear waste?

    USGS Publications Warehouse

    Neuzil, C.E.

    2013-01-01

    "Even as cleanup efforts after Japan’s Fukushima disaster offer a stark reminder of the spent nuclear fuel (SNF) stored at nuclear plants worldwide, the decision in 2009 to scrap Yucca Mountain as a permanent disposal site has dimmed hope for a repository for SNF and other high-level nuclear waste (HLW) in the United States anytime soon. About 70,000 metric tons of SNF are now in pool or dry cask storage at 75 sites across the United States [Government Accountability Office, 2012], and uncertainty about its fate is hobbling future development of nuclear power, increasing costs for utilities, and creating a liability for American taxpayers [Blue Ribbon Commission on America’s Nuclear Future, 2012].However, abandoning Yucca Mountain could also result in broadening geologic options for hosting America’s nuclear waste. Shales and other argillaceous formations (mudrocks, clays, and similar clay-rich media) have been absent from the U.S. repository program. In contrast, France, Switzerland, and Belgium are now planning repositories in argillaceous formations after extensive research in underground laboratories on the safety and feasibility of such an approach [Blue Ribbon Commission on America’s Nuclear Future, 2012; Nationale Genossenschaft für die Lagerung radioaktiver Abfälle (NAGRA), 2010; Organisme national des déchets radioactifs et des matières fissiles enrichies, 2011]. Other nations, notably Japan, Canada, and the United Kingdom, are studying argillaceous formations or may consider them in their siting programs [Japan Atomic Energy Agency, 2012; Nuclear Waste Management Organization (NWMO), (2011a); Powell et al., 2010]."

  18. Depleted uranium as a backfill for nuclear fuel waste package

    DOEpatents

    Forsberg, C.W.

    1998-11-03

    A method is described for packaging spent nuclear fuel for long-term disposal in a geological repository. At least one spent nuclear fuel assembly is first placed in an unsealed waste package and a depleted uranium fill material is added to the waste package. The depleted uranium fill material comprises flowable particles having a size sufficient to substantially fill any voids in and around the assembly and contains isotopically-depleted uranium in the +4 valence state in an amount sufficient to inhibit dissolution of the spent nuclear fuel from the assembly into a surrounding medium and to lessen the potential for nuclear criticality inside the repository in the event of failure of the waste package. Last, the waste package is sealed, thereby substantially reducing the release of radionuclides into the surrounding medium, while simultaneously providing radiation shielding and increased structural integrity of the waste package. 6 figs.

  19. Depleted uranium as a backfill for nuclear fuel waste package

    DOEpatents

    Forsberg, Charles W.

    1998-01-01

    A method for packaging spent nuclear fuel for long-term disposal in a geological repository. At least one spent nuclear fuel assembly is first placed in an unsealed waste package and a depleted uranium fill material is added to the waste package. The depleted uranium fill material comprises flowable particles having a size sufficient to substantially fill any voids in and around the assembly and contains isotopically-depleted uranium in the +4 valence state in an amount sufficient to inhibit dissolution of the spent nuclear fuel from the assembly into a surrounding medium and to lessen the potential for nuclear criticality inside the repository in the event of failure of the waste package. Last, the waste package is sealed, thereby substantially reducing the release of radionuclides into the surrounding medium, while simultaneously providing radiation shielding and increased structural integrity of the waste package.

  20. Prediction of water seepage into a geologic repository for high-level radioactive waste

    SciTech Connect

    Birkholzer, Jens; Mukhophadhyay, Sumit; Tsang, Yvonne

    2003-07-07

    Predicting the amount of water that may seep into waste emplacement drifts is important for assessing the performance of the proposed geologic repository for high-level radioactive waste at Yucca Mountain, Nevada. The repository would be located in thick, partially saturated fractured tuff that will be heated to above-boiling temperatures as a result of heat generation from the decay of nuclear waste. Since infiltrating water will be subject to vigorous boiling for a significant time period, the superheated rock zone (i.e., rock temperature above the boiling point of water) can form an effective vaporization barrier that reduces the possibility of water arrival at emplacement drifts. In this paper, we analyze the behavior of episodic preferential flow events that penetrate the hot fractured rock, evaluate the impact of such flow behavior on the effectiveness of the vaporization barrier, and discuss the implications for the performance assessment of the repository. A semi-analytical solution is utilized to determine the complex flow processes in the hot rock environment. The solution is applied at several discrete times after emplacement, covering the time period of strongly elevated temperatures at Yucca Mountain.

  1. New constraints on 1.7 Gyr of brittle tectonic evolution in southwestern Finland derived from a structural study at the site of a potential nuclear waste repository (Olkiluoto Island)

    NASA Astrophysics Data System (ADS)

    Mattila, Jussi; Viola, Giulio

    2014-10-01

    The brittle deformation history of southwestern Finland was reconstructed through paleostress inversion of fault-slip data from outcrops and drill cores at the site of a planned nuclear waste repository. Seven distinct paleostress states have been resolved spanning 1.7 Ga of geological history. (1) NW-SE to NNW-SSE transpression acted soon after 1.75 Ga, when conditions leading to brittle deformation were first attained. (2) N-S to NE-SW transpression caused partial reactivation of (1). (3) NW-SE extension followed during the Gothian event and at the time of rapakivi magmatism. (4) Renewed NE-SW transtension occurred between 1.60 and 1.30 Ga, forming the NW-SE-elongated Satakunta graben. (5) A significant and so far unrecognised phase of NE-SW compression has been found to postdate both rapakivi granites and 1.27 Ga olivine diabase sills. (6) E-W transpression followed during the early stages of the Mesoproterozoic Sveconorwegian orogeny and predated (7) almost coaxial E-W extension of the late Sveconorwegian orogenic collapse. Our results prove that the shield's 'crust fragmentation' (i.e. generation of new fractures) was short lived in comparison to its 'jostling phase' (i.e. reactivation of old fractures). The shield thus reached structural maturity with respect to its saturation with brittle structures already in the late Mesoproterozoic. We predict that that future stress changes will most probably be accommodated by reactivation of the existing and inherited brittle structures rather than by formation of new deformation zones.

  2. Environmental Hazards of Nuclear Wastes

    ERIC Educational Resources Information Center

    Micklin, Philip P.

    1974-01-01

    Present methods for storage of radioactive wastes produced at nuclear power facilities are described. Problems arising from present waste management are discussed and potential solutions explored. (JP)

  3. Nevada Nuclear Waste Storage Investigations Project: thermal analysis of spent fuel disposal in vertical emplacement boreholes in a welded tuff repository

    SciTech Connect

    St. John, C.M.

    1985-11-01

    Two- and three-dimensional heat transfer analyses were conducted to determine temperatures in the vicinity of a waste canister and an emplacement drift. The effect of emplacement of canisters containing spent fuel in vertical boreholes was simulated for the cases of an emplacement drift either fully ventilated or sealed immediately after canister emplacement. PORFLOW and THERM3D respectively solve the two- and three-dimensional forms of the diffusion equation. In the unventilated case, the effect of radiation was approximated by defining an equivalent radiation thermal conductivity. A simple code, TEMP3D, based on the closed form solutions for constant and decaying heat sources, was also used. Calculations indicate that the temperature at the canister borehole wall will peak at about 215{sup 0}C if the drift is ventilated and about 240{sup 0}C if it is unventilated. The peak temperature occurs sooner in the ventilated case; after 3 to 4 yr versus 9 yr. For a point 1 m from the wall of the emplacement borehole, the corresponding peak temperatures are 150{sup 0}C for the ventilated case and 185{sup 0}C for the unventilated case and occur at about 5 and 17 yr. We assumed that the effect of drift ventilation would be to maintain a uniform temperature of 30{sup 0}C at the drift perimeter. If the drift is unventilated the wall rock temperature peaks some 75 to 100 yr after waste emplacement; reaching about 125{sup 0}C at the mid-height of the drift wall. Comparisons between the results of the three-dimensional analyses performed using TEMP3D and THERM3D indicated that the simpler modeling technique provided a good estimate of temperatures in the immediate vicinity of the canister for both the ventilated and unventilated cases. Comparisons of the results of two- and three-dimensional analyses performed using the PORFLOW and THERM3D codes indicated that the two-dimensional approximation is excellent, except in the immediate vicinity of the canister.

  4. Analogues to features and processes of a high-level radioactive waste repository proposed for Yucca Mountain, Nevada

    USGS Publications Warehouse

    Simmons, Ardyth M.; Stuckless, John S.; with a Foreword by Abraham Van Luik, U.S. Department of Energy

    2010-01-01

    Natural analogues are defined for this report as naturally occurring or anthropogenic systems in which processes similar to those expected to occur in a nuclear waste repository are thought to have taken place over time periods of decades to millennia and on spatial scales as much as tens of kilometers. Analogues provide an important temporal and spatial dimension that cannot be tested by laboratory or field-scale experiments. Analogues provide one of the multiple lines of evidence intended to increase confidence in the safe geologic disposal of high-level radioactive waste. Although the work in this report was completed specifically for Yucca Mountain, Nevada, as the proposed geologic repository for high-level radioactive waste under the U.S. Nuclear Waste Policy Act, the applicability of the science, analyses, and interpretations is not limited to a specific site. Natural and anthropogenic analogues have provided and can continue to provide value in understanding features and processes of importance across a wide variety of topics in addressing the challenges of geologic isolation of radioactive waste and also as a contribution to scientific investigations unrelated to waste disposal. Isolation of radioactive waste at a mined geologic repository would be through a combination of natural features and engineered barriers. In this report we examine analogues to many of the various components of the Yucca Mountain system, including the preservation of materials in unsaturated environments, flow of water through unsaturated volcanic tuff, seepage into repository drifts, repository drift stability, stability and alteration of waste forms and components of the engineered barrier system, and transport of radionuclides through unsaturated and saturated rock zones.

  5. Radiation effects in a model ceramic for nuclear waste disposal

    NASA Astrophysics Data System (ADS)

    Devanathan, Ram; Weber, William J.

    2007-04-01

    The safe immobilization of nuclear waste in geological repositories is one of the major scientific challenges facing humanity today. Crystalline ceramics hold the promise of locking up actinides from nuclear fuel and excess weapons plutonium in their structure thereby isolating them from the environment. This paper presents the atomistic details of radiation damage in a model ceramic, zircon.

  6. Nuclear waste: Quarterly report on DOE`s nuclear waste program as of March 31, 1988

    SciTech Connect

    1988-12-31

    As part of the Department of Energy`s implementation of the Nuclear Waste Policy Act of 1982, DOE is required to investigate a site at Yucca Mountain, Nevada and, if it determines that the site is suitable, recommend to the President its selection for a nuclear waste repository. The Nuclear Regulatory Commission, in considering development of the plan, issued five objections, one of which is DOE`s failure to recognize the range of alternative conceptual models of the Yucca Mountain site that can be supported by the limited existing technical data. At the end of the quarter DOE directed its project offices in Washington and Texas to begin an orderly phase-out of all site-specific repository activities. Costs for this phase-out are $53 million of the Deaf Smith site and $85 million for the Hanford site.

  7. Analysis of DOE Spent Nuclear Fuels for Repository Disposal

    SciTech Connect

    L.F. Pincock; W.D. Hintze; J. Duguid

    2006-02-07

    U.S. Department of Energy (DOE) spent nuclear fuel (SNF) consists of hundreds of different fuel types in various conditions. In order to analyze and model the DOE SNF for its suitability for repository disposal, several generalizations and simplifications were necessary. This paper describes the methodology used to arrive at a suitable DOE SNF surrogate and summarizes the proposed analysis of this DOE SNF surrogate for its appropriateness as a representative SNF.

  8. Science, Society, and America's Nuclear Waste: The Waste Management System, Unit 4. Teacher Guide. Second Edition.

    ERIC Educational Resources Information Center

    Department of Energy, Washington, DC. Office of Civilian Radioactive Waste Management, Washington, DC.

    This guide is Unit 4 of the four-part series, Science, Society, and America's Nuclear Waste, produced by the U.S. Department of Energy's Office Civilian Radioactive Waste Management. The goal of this unit is to explain how transportation, a geologic repository, and the multi-purpose canister will work together to provide short-term and long-term…

  9. Nuclear waste`s human dimension

    SciTech Connect

    Erikson, K.; Colglazier, E.W.; White, G.F.

    1994-12-31

    The United States has pinned its hopes for a permanent underground repository for its high-level nuclear wastes on Yucca Mountain, Nevada. Nevertheless, the Department of Energy`s (DOE) site research efforts have failed {open_quotes}to adequately consider human behavior and emotions,{close_quotes} write Kai Erikson of Yale University, E. William Colglazier of the National Academy of Sciences, and Gilbert F. White of the University of Colorado. The authors maintain that it is impossible to predict changes in geology, seismology, and hydrology that may affect the Yucca Mountain area over the next 1,000 years. Predicting human behavior in that time frame remains even more daunting, they insist. They admit that {open_quotes}DOE...has been given the impossible assignment to take tens of thousands of metric tons of the most hazardous materials ever created and, in the face of growing opposition, entomb them so that they will do little harm for thousands of years.{close_quotes} The researchers suggest that the government seek a secure, retrievable storage arrangement while it continues its search for safer long-term options.

  10. DEVELOPMENT OF THE SWEDISH DEEP REPOSITORY FOR SPENT NUCLEAR FUEL IN CRYSTALLINE HOST ROCK

    SciTech Connect

    Pettersson, Stig; Widing, Eva

    2003-02-27

    The Swedish Nuclear Fuel and Waste Management Company, SKB, has developed a system that ensures the safe handling of all kinds of radioactive waste from the Swedish nuclear power plants for a long time period ahead. The keystones of this system are: A transport system with the ship M/S Sigyn which has been in operation since 1983. A central interim storage facility for spent nuclear fuel, CLAB, in operation since 1985. A final repository for short-lived, low and intermediate level waste, SFR, in operation since 1988. In Sweden, the preferred method for final disposal of spent fuel is to encapsulate it in copper canisters and dispose them in a deep geological repository in crystalline host rock. SKB is planning to build an encapsulation plant adjacent to the central storage for spent fuel, CLAB. The siting for the deep repository has not yet been selected. A siting program with feasibility studies was completed in 2001. Early 2002 SKB received the necessary permits to start the site investigation at two potential sites for siting of the deep repository in Sweden. The site investigation at these sites started early 2002 and will be completed during 2007. Over the years, a number of generic studies of the layout of the operational area(s) above ground and underground facilities have been performed. During the site investigation phase the deep repository will be developed to conceptual design status and a number of design studies will be performed. These design studies are called Design Justification Statements (DJS). One important DJS is the selection of access routes from the ground level to the disposal level at tentatively 500 m depth and that study will be completed shortly. The repository design and layout of the disposal areas will be based on site specific conditions and results from demonstration of handling and equipment for canisters, buffer and backfilling. Some of these demonstrations have already been performed at Dspv HRL but additional development and

  11. Parametric study of geohydrologic performance characteristics for geologic waste repositories

    SciTech Connect

    Bailey, C.E.; Marine, I.W.

    1980-11-01

    One of the major objectives of the National Waste Terminal Storage Program is to identify potential geologic sites for storage and isolation of radioactive waste (and possibly irradiated fuel). Potential sites for the storage and isolation of radioactive waste or spent fuel in a geologic rock unit are being carefully evaluated to ensure that radionuclides from the stored waste or fuel will never appear in the biosphere in amounts that would constitute a hazard to the health and safety of the public. The objective of this report is to quantify and present in graphical form the effects of significant geohydrologic and other performance characteristics that would influence the movement of radionuclides from a storage site in a rock unit to the biosphere. The effort in this study was focused on transport by groundwater because that is the most likely method of radionuclide escape. Graphs of the major performance characteristics that influence the transport of radionuclides from a repository to the biosphere by groundwater are presented. The major characteristics addressed are radioactive decay, leach rate, hydraulic conductivity, porosity, groundwater gradient, hydrodynamic dispersion, ion exchange, and distance to the biosphere. These major performance characteristics are combind with each other and with the results of certain other combinations and presented in graphical form to provide the interrelationships of values measured during field studies. The graphical form of presentation should be useful in the screening process of site selection. An appendix illustrates the use of these graphs to assess the suitability of a site.

  12. Salt disposal of heat-generating nuclear waste.

    SciTech Connect

    Leigh, Christi D.; Hansen, Francis D.

    2011-01-01

    This report summarizes the state of salt repository science, reviews many of the technical issues pertaining to disposal of heat-generating nuclear waste in salt, and proposes several avenues for future science-based activities to further the technical basis for disposal in salt. There are extensive salt formations in the forty-eight contiguous states, and many of them may be worthy of consideration for nuclear waste disposal. The United States has extensive experience in salt repository sciences, including an operating facility for disposal of transuranic wastes. The scientific background for salt disposal including laboratory and field tests at ambient and elevated temperature, principles of salt behavior, potential for fracture damage and its mitigation, seal systems, chemical conditions, advanced modeling capabilities and near-future developments, performance assessment processes, and international collaboration are all discussed. The discussion of salt disposal issues is brought current, including a summary of recent international workshops dedicated to high-level waste disposal in salt. Lessons learned from Sandia National Laboratories' experience on the Waste Isolation Pilot Plant and the Yucca Mountain Project as well as related salt experience with the Strategic Petroleum Reserve are applied in this assessment. Disposal of heat-generating nuclear waste in a suitable salt formation is attractive because the material is essentially impermeable, self-sealing, and thermally conductive. Conditions are chemically beneficial, and a significant experience base exists in understanding this environment. Within the period of institutional control, overburden pressure will seal fractures and provide a repository setting that limits radionuclide movement. A salt repository could potentially achieve total containment, with no releases to the environment in undisturbed scenarios for as long as the region is geologically stable. Much of the experience gained from United

  13. The Nuclear Waste Policy Act, as amended with appropriations acts appended

    SciTech Connect

    Not Available

    1994-03-01

    The Nuclear Waste Policy Act of 1982 provides for the development of repositories for the disposal of high-level radioactive waste and spent nuclear fuel, to establish a program of research, development and demonstration regarding the disposal of high-level radioactive waste and spent nuclear fuel. Titles 1 and 2 cover these subjects. Also included in this Act are: Title 3: Other provisions relating to radioactive waste; Title 4: Nuclear waste negotiation; Title 5: Nuclear waste technical review board; and Title 6: High-level radioactive waste. An appendix contains excerpts from appropriations acts from fiscal year 1984--1994.

  14. Geopolitics of nuclear waste

    SciTech Connect

    Marshall, E.

    1991-02-22

    More debate has begun over questions related to the safety of high-level waste disposal at the Yucca Mountain site in the Nevada desert. An engineering geologists, Jerry Szymanski, one of the Department of Energy`s (DOE) own staffers in Las Vegas, has proposed that the $15-billion repository would sit on top of an intensely active structure that, if altered by an earthquake, would send a slug of ground water up from deep within the mountain into the waste storage area. This theory has already been slammed in two formal reviews and has virtually no support among geologists. However, enough doubt has been raised that much more geological testing will be necessary to prove or disprove Szymanski`s theory. Nevada state officials are also using all methods to thwart or block the project. The question of the origin of a series of calcium carbonate and opal veins exposed in an exploratory pit, trench 14, near the top of the mountain is also far from answered. The DOE and US Geological Survey may have to collect much more information on the quantity, size, and location of carbonate sites in the area at a high financial outlay to the US government before a complete case on the origin of the material in trench 14 can be made.

  15. Waste package reference conceptual designs for a repository in salt

    SciTech Connect

    Not Available

    1986-02-01

    This report provides the reference conceptual waste package designs for the Office of Nuclear Waste Isolation to baseline these designs, thereby establishing the configuration and interface controls necessary, within the Civilian Radioactive Waste Management Program, formerly the National Waste Terminal Storage Program, to proceed in an orderly manner with preliminary design. Included are designs for the current reference defense high-level waste form from the Savannah River Plant, an optimized commercial high-level waste form, and spent fuel which has been disassembled and compacted into a circular bundle containing either 12 pressurized-water reactor or 30 boiling-water reactor assemblies. For compacted spent fuel, it appears economically attractive to standardize the waste package diameter for all fuel types. The reference waste packages consist of the containerized waste form, a low carbon steel overpack, and, after emplacement, a cover of salt. The overpack is a hollow cylinder with a flat head welded to each end. Its design thickness is the sum of the structural thickness required to resist the 15.4-MPa lithostatic pressure plus the corrosion allowance necessary to assure the required structural thickness will exist through the 1000-year containment period. Based on available data and completed analyses, the reference concepts described in this report satisfy all requirements of the US Department of Energy and the US Nuclear Regulatory Commission with reasonable assurance. In addition, sufficient design maturity exists to form a basis for preliminary design; these concepts can be brought under configuration control to serve as reference package designs. Development programs are identified that will be required to support these designs during the licensing process. 19 refs., 37 figs., 31 tabs.

  16. Canada's Deep Geological Repository for Used Nuclear Fuel - Geo-scientific Site Evaluation Process - 13117

    SciTech Connect

    Blyth, Alec; Ben Belfadhel, Mahrez; Hirschorn, Sarah; Hamilton, Duncan; McKelvie, Jennifer

    2013-07-01

    The Nuclear Waste Management Organization (NWMO) is responsible for implementing Adaptive Phased Management (APM), the approach selected by the Government of Canada for long-term management of used nuclear fuel generated by Canadian nuclear reactors. The ultimate objective of APM is the centralized containment and isolation of Canada's used nuclear fuel in a Deep Geological Repository in a suitable rock formation at a depth of approximately 500 meters (m) (1,640 feet [ft]). In May 2010, the NWMO published a nine-step site selection process that serves as the road map to decision-making on the location for the deep geological repository. The safety and appropriateness of any potential site will be assessed against a number of factors, both technical and social in nature. The selected site will be one that can be demonstrated to be able to safely contain and isolate used nuclear fuel, protecting humans and the environment over the very long term. The geo-scientific suitability of potential candidate sites will be assessed in a stepwise manner following a progressive and thorough site evaluation process that addresses a series of geo-scientific factors revolving around five safety functions. The geo-scientific site evaluation process includes: Initial Screenings; Preliminary Assessments; and Detailed Site Evaluations. As of November 2012, 22 communities have entered the site selection process (three in northern Saskatchewan and 18 in northwestern and southwestern Ontario). (authors)

  17. Mass transfer and transport of radionuclides through backfill in a geologic nuclear waster repository

    SciTech Connect

    Kang, Chulhyung.

    1989-01-01

    Analytical models for the mass transfer and transport of radionuclides through waste package backfill material are developed and their numerical illustrations are demonstrated. These models can aid in the performance assessment of the waste package in nuclear waste repositories. The following analyses are considered to study the performance of the backfill barrier in a geologic nuclear waste repository. (1) The analysis for time and space dependent mass transfer and mass transport of a radioactive decay chain for a congruent release with the matrix species is studied. Non-recursive analytical solutions are derived for a semi-infinite medium and a finite medium. The theory is illustrated with the important decay chain {sup 234}U {yields} {sup 230}Th {yields} {sup 226}Ra. (2) The time and space dependent mass transport for high solubility nuclides, such as iodine or cesium, is analyzed. The approximate solution that is valid for all times is developed, and validated by comparison with an asymptotic solution and the solution obtained by the numerical inversion of a Laplace transform covering the entire time span. From this model one can determine the thickness of the backfill to satisfy a prescribed release rate limit for high soluble radionuclides. (3) The analysis of the transient radionuclide migration through the backfill into a fracture intersecting the waste form is developed. The nuclides are advected by water flowing in the fracture. The numerical illustrations show that the species transport for the short half-life nuclide can be stopped effectively within the backfill, but the backfill can no longer retard the migration for stable nuclides or long half-life nuclides after some initial time period. (4) The steady state mass transfer from a cylindrical waste form with flow through the backfill layer is examined.

  18. Turning nuclear waste into glass

    SciTech Connect

    Pegg, Ian L.

    2015-02-15

    Vitrification has emerged as the treatment option of choice for the most dangerous radioactive waste. But dealing with the nuclear waste legacy of the Cold War will require state-of-the-art facilities and advanced glass formulations.

  19. Nevada may lose nuclear waste funds

    SciTech Connect

    Marshall, E.

    1988-06-24

    The people of Nevada are concerned that a cut in DOE funding for a nuclear waste repository at Yucca Mountain, Nevada will result in cuts in the state monitoring program, e.g. dropping a seismic monitoring network and a sophisticated drilling program. Economic and social impact studies will be curtailed. Even though a provision to curtail local research forbids duplication of DOE`s work and would limit the ability of Nevada to go out and collect its own data, Nevada State University at Las Vegas would receive a nice plum, a top-of-the-line supercomputer known as the ETA-10 costing almost $30 million financed by DOE.

  20. Consideration of nuclear criticality when disposing of transuranic waste at the Waste Isolation Pilot Plant

    SciTech Connect

    RECHARD,ROBERT P.; SANCHEZ,LAWRENCE C.; STOCKMAN,CHRISTINE T.; TRELLUE,HOLLY R.

    2000-04-01

    Based on general arguments presented in this report, nuclear criticality was eliminated from performance assessment calculations for the Waste Isolation Pilot Plant (WIPP), a repository for waste contaminated with transuranic (TRU) radioisotopes, located in southeastern New Mexico. At the WIPP, the probability of criticality within the repository is low because mechanisms to concentrate the fissile radioisotopes dispersed throughout the waste are absent. In addition, following an inadvertent human intrusion into the repository (an event that must be considered because of safety regulations), the probability of nuclear criticality away from the repository is low because (1) the amount of fissile mass transported over 10,000 yr is predicted to be small, (2) often there are insufficient spaces in the advective pore space (e.g., macroscopic fractures) to provide sufficient thickness for precipitation of fissile material, and (3) there is no credible mechanism to counteract the natural tendency of the material to disperse during transport and instead concentrate fissile material in a small enough volume for it to form a critical concentration. Furthermore, before a criticality would have the potential to affect human health after closure of the repository--assuming that a criticality could occur--it would have to either (1) degrade the ability of the disposal system to contain nuclear waste or (2) produce significantly more radioisotopes than originally present. Neither of these situations can occur at the WIPP; thus, the consequences of a criticality are also low.

  1. Safety Assessment for VLLW Disposal at the National Radioactive Waste Repository Mochovce in Slovakia - 13508

    SciTech Connect

    Biurrun, E.; Haverkamp, B.; Lazaro, A.; Miralles, A.

    2013-07-01

    Recent developments in the Slovak Republic have prompted the need to introduce the new category of very low level waste (VLLW) in the operation of the country's repository for low and intermediate level radioactive waste (LILW). By doing this, significant savings are expected to be achieved while disposing the waste resulting from early decommissioning of older, Soviet type reactors. To study the feasibility and the likely impact of such introduction, a project was launched and assigned in international competition to a German-Spanish consortium. The study confirmed by means of a safety assessment the feasibility of this waste category in the specific context of the Slovakian repository. Moreover, the advantages that such new waste category would render were stressed and the best option for enlargement of the repository, the construction of a module for LILW disposal within the limits of the existing repository, was identified. (authors)

  2. Underground nuclear waste containments

    SciTech Connect

    Bandyopadhyay, K.K.

    1995-11-01

    In the United States, about a hundred million gallons of high-level nuclear waste are stored in underground containments. Basically, these containments are of two different designs: single-shell and double-shell structures. The single-shell structures consist of reinforced concrete cylindrical walls seated on circular mats and enclosed on top with torispherical domes or circular flat roofs. The walls and the basemats are lined with carbon steel. The double-shell structures provide another layer of protection and constitute a completely enclosed steel containment within the single-shell structure leaving an annular space between the two walls. Single-shell containments are of earlier vintage and were built in the period 1945-1965. Double-shell structures were built through the 1960s and 1970s. Experience gained in building and operating the single-shell containments was used in enhancing the design and construction of the double-shell structures. Currently, there are about 250 underground single-shell and double-shell structures containing the high-level waste with an inventory of about 800 million curies. During their service lives, especially in early stages, these structures were subjected to thermal excursions of varying extents; also, they have aged in the chemical environment. Furthermore, in their remaining service lives, the structures may be subjected to loads for which they were not designed, such as larger earthquakes or chemical explosions. As a result, the demonstration of safety of these underground nuclear containments poses a challenge to structural engineers, which increases with time. Regardless of current plans for gradual retrieval of the waste and subsequent solidification for disposal, many of these structures are expected to continue to contain the waste through the next 20-40 years. In order to verify their structural capabilities in fulfilling this mission, several studies were recently performed at Brookhaven National Laboratory.

  3. Local negotiation on compensation siting of the spent nuclear fuel repository in Finland

    SciTech Connect

    Kojo, Matti

    2007-07-01

    The aim of the paper is to analyse the local negotiation process between the Municipality of Eurajoki and the nuclear power company Teollisuuden Voima (TVO) and the nuclear waste management company Posiva Oy. The aim of the negotiations was to find an acceptable form of compensation for siting a spent nuclear fuel repository in Olkiluoto, Finland. The paper includes background information on the siting process in Finland, the local political setting in the Municipality of Eurajoki and a description of the negotiation process. The analysis of the negotiations on compensation is important for better understanding the progress of the Finnish siting process. The paper describes the picture of the contest to host the spent nuclear fuel repository. It also provides more information on the relationship between the Municipality of Eurajoki and the power company TVO. The negotiations on compensation and the roles of various players in the negotiations have not been studied in detail because the minutes of the Vuojoki liaison group were not available before the decision of the Supreme Administrative Court in May 2006. (author)

  4. Reference waste forms and packing material for the Nevada Nuclear Waste Storage Investigations Project

    SciTech Connect

    Oversby, V.M.

    1984-03-30

    The Lawrence Livermore National Laboratory (LLNL), Livermore, Calif., has been given the task of designing and verifying the performance of waste packages for the Nevada Nuclear Waste Storage Investigations (NNWSI) Project. NNWSI is studying the suitability of the tuffaceous rocks at Yucca Mountain, Nevada Test Site, for the potential construction of a high-level nuclear waste repository. This report gives a summary description of the three waste forms for which LLNL is designing waste packages: spent fuel, either as intact assemblies or as consolidated fuel pins, reprocessed commercial high-level waste in the form of borosilicate glass, and reprocessed defense high-level waste from the Defense Waste Processing Facility in Aiken, S.C. Reference packing material for use with the alternative waste package design for spent fuel is also described. 14 references, 8 figures, 20 tables.

  5. The use of conditional simulation in nuclear-waste-site performance assessment

    SciTech Connect

    Gotway, C.A.

    1994-05-01

    Stochastic simulation methodology is becoming an important tool for evaluating the performance of potential nuclear-waste repositories. This article presents an overview of such methodology as it is currently used in many waste-management applications. Details involved with the statistical and geostatistical analyses of relevant hydrogeologic variables are provided in a simulation study of groundwater travel time through an aquifer overlying the Waste Isolation Pilot Plant repository in southeastern New Mexico.

  6. A Method to Evaluate Additional Waste Forms to Optimize Performance of the HLW Repository

    SciTech Connect

    D. Gombert; L. Lauerhass

    2006-02-01

    The DOE high-level waste (HLW) disposal system is based on decisions made in the 1970s. The de facto Yucca Mountain WAC for HLW, contained in the Waste Acceptance System Requirements Document (WASRD), and the DOE-EM Waste Acceptance Product Specification for Vitrified High Level Waste Forms (WAPS) tentatively describes waste forms to be interred in the repository, and limits them to borosilicate glass (BSG). It is known that many developed waste forms are as durable as or better than environmental assessment or “EA”-glass. Among them are the salt-ceramic and metallic waste forms developed at ANL-W. Also, iron phosphate glasses developed at University of Missouri show promise in stabilizing the most refractory materials in Hanford HLW. However, for any of this science to contribute, the current Total System Performance Assessment model must be able to evaluate the additional waste form to determine potential impacts on repository performance. The results can then support the technical bases required in the repository license application. A methodology is proposed to use existing analysis models to evaluate potential additional waste forms for disposal without gathering costly material specific degradation data. The concept is to analyze the potential impacts of waste form chemical makeup on repository performance assuming instantaneous waste matrix dissolution. This assumption obviates the need for material specific degradation models and is based on the relatively modest fractional contribution DOE HLW makes to the repository radionuclide and hazardous metals inventory. The existing analysis models, with appropriate data modifications, are used to evaluate geochemical interactions and material transport through the repository. This methodology would support early screening of proposed waste forms through simplified evaluation of disposal performance, and would provide preliminary guidance for repository license amendment in the future.

  7. State of Nevada, Agency for Nuclear Projects/Nuclear Waste Project Office narrative report, January 1992

    SciTech Connect

    1992-12-31

    The Agency for Nuclear Projects/Nuclear Waste Project Office (NWPO) is the State of Nevada agency designated by State law to monitor and oversee US Department of Energy (DOE) activities relative to the possible siting, construction, operation and closure of a high-level nuclear waste repository at Yucca Mountain and to carry out the State of Nevada`s responsibilities under the Nuclear Waste Policy Act of 1982. During the reporting period the NWPO continued to work toward the five objectives designed to implement the Agency`s oversight responsibilities: (1) Assure that the health and safety of Nevada`s citizens are adequately protected with regard to any federal high-level radioactive waste program within the State; (2) Take the responsibilities and perform the duties of the State of Nevada as described in the Nuclear Waste Policy Act of 1982 (Public Law 97-425) and the Nuclear Waste Policy Amendments Act of 1987; (3) Advise the Governor, the State Commission on Nuclear Projects and the Nevada State Legislature on matters concerning the potential disposal of high-level radioactive waste in the State; (4) Work closely and consult with affected local governments and State agencies; (5) Monitor and evaluate federal planning and activities regarding high-level radioactive waste disposal. Plan and conduct independent State studies regarding the proposed repository.

  8. Assessment of high-level waste form conformance with proposed regulatory and repository criteria

    SciTech Connect

    Gordon, D E; Gray, P L; Jennings, A S; Permar, P H

    1982-04-01

    Federal regulatory criteria for geologic disposal of high-level waste are under development. Also, interim performance specifications for high-level waste forms in geologic isolation are being developed within the Federal program responsible for repository selection and operation. Two high-level waste forms, borosilicate glass and crystalline ceramic, have been selected as candidate immobilization forms for the Defense Waste Processing Facility (DWPF) which is to immobilize high-level wastes at the Savannah River Plant (SRP). An assessment of how these two waste forms conform with the proposed regulatory criteria and repository specifications was performed. Both forms were determined to be in conformance with postulated rules for radionuclide releases and radiation exposures throughout the entire waste disposal system, as well as with proposed repository operation requirements.

  9. Influence of climate on landscape characteristics in safety assessments of repositories for radioactive wastes.

    PubMed

    Becker, J K; Lindborg, T; Thorne, M C

    2014-12-01

    In safety assessments of repositories for radioactive wastes, large spatial and temporal scales have to be considered when developing an approach to risk calculations. A wide range of different types of information may be required. Local to the site of interest, temperature and precipitation data may be used to determine the erosional regime (which may also be conditioned by the vegetation characteristics adopted, based both on climatic and other considerations). However, geomorphological changes may be governed by regional rather than local considerations, e.g. alteration of river base levels, river capture and drainage network reorganisation, or the progression of an ice sheet or valley glacier across the site. The regional climate is in turn governed by the global climate. In this work, a commentary is presented on the types of climate models that can be used to develop projections of climate change for use in post-closure radiological impact assessments of geological repositories for radioactive wastes. These models include both Atmosphere-Ocean General Circulation Models and Earth Models of Intermediate Complexity. The relevant outputs available from these models are identified and consideration is given to how these outputs may be used to inform projections of landscape development. Issues of spatial and temporal downscaling of climate model outputs to meet the requirements of local-scale landscape development modelling are also addressed. An example is given of how climate change and landscape development influence the radiological impact of radionuclides potentially released from the deep geological disposal facility for spent nuclear fuel that SKB (the Swedish Nuclear Fuel and Waste Management Company) proposes to construct at Forsmark, Sweden.

  10. Influence of climate on landscape characteristics in safety assessments of repositories for radioactive wastes.

    PubMed

    Becker, J K; Lindborg, T; Thorne, M C

    2014-12-01

    In safety assessments of repositories for radioactive wastes, large spatial and temporal scales have to be considered when developing an approach to risk calculations. A wide range of different types of information may be required. Local to the site of interest, temperature and precipitation data may be used to determine the erosional regime (which may also be conditioned by the vegetation characteristics adopted, based both on climatic and other considerations). However, geomorphological changes may be governed by regional rather than local considerations, e.g. alteration of river base levels, river capture and drainage network reorganisation, or the progression of an ice sheet or valley glacier across the site. The regional climate is in turn governed by the global climate. In this work, a commentary is presented on the types of climate models that can be used to develop projections of climate change for use in post-closure radiological impact assessments of geological repositories for radioactive wastes. These models include both Atmosphere-Ocean General Circulation Models and Earth Models of Intermediate Complexity. The relevant outputs available from these models are identified and consideration is given to how these outputs may be used to inform projections of landscape development. Issues of spatial and temporal downscaling of climate model outputs to meet the requirements of local-scale landscape development modelling are also addressed. An example is given of how climate change and landscape development influence the radiological impact of radionuclides potentially released from the deep geological disposal facility for spent nuclear fuel that SKB (the Swedish Nuclear Fuel and Waste Management Company) proposes to construct at Forsmark, Sweden. PMID:25255485

  11. Waste canister for storage of nuclear wastes

    DOEpatents

    Duffy, James B.

    1977-01-01

    A waste canister for storage of nuclear wastes in the form of a solidified glass includes fins supported from the center with the tips of the fins spaced away from the wall to conduct heat away from the center without producing unacceptable hot spots in the canister wall.

  12. WORKSHOP ON DEVELOPMENT OF RADIONUCLIDE GETTERS FOR THE YUCCA MOUNTAIN WASTE REPOSITORY

    SciTech Connect

    K.C. Holt

    2006-03-13

    One of the important that the U.S. Department of Energy (DOE) is currently undertaking is the development of a high-level nuclear waste repository to be located at Yucca Mountain, Nevada. Concern is generated by the Yucca Mountain Project (YMP) is due to potential releases as groundwater contamination, as described in the Total System Performance Assessment (TSPA). The dose to an off-site individual using this groundwater for drinking and irrigation is dominated by four radionuclides: Tc-99, I-127, Np-237, and U-238. Ideally, this dose would be limited to a single radionuclide, U-238; in other words, YMP would resemble a uranium ore body, a common geologic feature in the Western U.S. For this reason and because of uncertainties in the behavior of Tc-99, I-127, and Np-237, it would be helpful to limit the amount of Tc, I, and Np leaving the repository, which would greatly increase the confidence in the long-term performance of YMP. An approach to limiting the migration of Tc, I, and Np that is complementary to the existing YMP repository design plans is to employ sequestering agents or ''getters'' for these radionuclides such that their migration is greatly hindered, thus decreasing the amount of radionuclide leaving the repository. Development of such getters presents a number of significant challenges. The getter must have a high affinity and high selectivity for the radionuclide in question since there is approximately a 20- to 50-fold excess of other fission products and a 1000-fold excess of uranium in addition to the ions present in the groundwater. An even greater challenge is that the getters must function over a period greater than the half-life of the radionuclide (greater than 5 half-lives would be ideal). Typically, materials with a high affinity for Tc, I, or Np are not sufficiently durable. For example, strong-base ion exchange resins have a very high affinity for TcO{sub 4}{sup -} but are not expected to be durable. On the other hand, durable

  13. Waste package for Yucca Mountain repository; Strategy for regulatory compliance

    SciTech Connect

    Cloninger, M.O.; Short, D.; Stahl, D.

    1989-12-31

    This paper summarizes the strategy given in the site characterization plan (SCP) for demonstrating compliance with the post closure performance objectives for the waste package and the engineered barrier system (EBS) contained in the Code of Federal Regulations, Title 10, Part 60 (10 CFR60), particularly 10 CFR 60,1113, and other applicable documents. The strategy consists of the development of a conservative waste package design that will meet the regulatory requirements with sufficient margin for uncertainty using a multi-barrier approach that takes advantage of the unsaturated nature of the Yucca Mountain site. This strategy involves an iterative process designed to achieve compliance with the requirements for substantially complete containment and EBS release. The strategy will be implemented in such a manner that sufficient evidence will be provided for presentation to the Nuclear Regulatory Commission (NRC) so that it may make a finding that there is reasonable assurance that these performance requirements will indeed be met.

  14. Nuclear waste disposal in space

    NASA Technical Reports Server (NTRS)

    Burns, R. E.; Causey, W. E.; Galloway, W. E.; Nelson, R. W.

    1978-01-01

    Work on nuclear waste disposal in space conducted by the George C. Marshall Space Flight Center, National Aeronautics and Space Administration, and contractors are reported. From the aggregate studies, it is concluded that space disposal of nuclear waste is technically feasible.

  15. Colloid formation during waste form reaction: implications for nuclear waste disposal

    USGS Publications Warehouse

    Bates, J. K.; Bradley, J.; Teetsov, A.; Bradley, C. R.; ten Brink, Marilyn Buchholtz

    1992-01-01

    Insoluble plutonium- and americium-bearing colloidal particles formed during simulated weathering of a high-level nuclear waste glass. Nearly 100 percent of the total plutonium and americium in test ground water was concentrated in these submicrometer particles. These results indicate that models of actinide mobility and repository integrity, which assume complete solubility of actinides in ground water, underestimate the potential for radionuclide release into the environment. A colloid-trapping mechanism may be necessary for a waste repository to meet long-term performance specifications.

  16. Glasses for nuclear waste immobilization

    SciTech Connect

    Ojovan, M.I.; Batyukhnova, O.G.

    2007-07-01

    Vitrification of nuclear wastes is attractive because of its flexibility, the large number of elements which can be incorporated in the glass, its high corrosion durability and the reduced volume of the resulting waste form. Vitrification is a mature technology and has been used for high level nuclear waste (HLW) immobilisation for more than 40 years in France, Germany and Belgium, Russia, UK, Japan and the USA. Vitrification involves melting of waste materials with glass-forming additives so that the final vitreous product incorporates the waste contaminants in its macro- and micro-structure. Hazardous waste constituents are immobilised either by direct incorporation into the glass structure or by encapsulation when the final glassy material can be in form of a glass composite material (GCM). Both borosilicate and phosphate glasses are currently used to immobilise nuclear wastes, moreover in addition to relatively homogeneous glasses novel GCM are used to immobilise problematic waste streams. The spectrum of wastes which are currently vitrified increases from HLW to low and intermediate wastes (LILW) such as legacy wastes in Hanford, USA and nuclear power plant operational wastes in Russia and Korea. (authors)

  17. Expected environments for a defense high-level waste repository in salt

    SciTech Connect

    Rickertsen, L.D.; Claiborne, H.C.

    1981-03-01

    Expected environments for a defense high-level waste (DHLW) repository in salt have been predicted analogously to previous analyses for spent fuel (SF) and reprocessed commercial high-level wastes (CHLW). Environments predicted include near-field and far-field temperatures, fluid, pressure, and nuclear radiation fields. Some sensitivity studies have also been performed. The main results of the calculations reported here include the following: (1) rock temperatures, canister wall temperatures, and waste temperatures do not exceed 86, 94, and 101/sup 0/C, respectively; (2) the maximum brine inflow rate to an emplacement hole is 0.015 L/yr, occurring in the first 30 yr after emplacement. The total accumulation of brine migrating to the emplacement hole after 1000 yr is < 0.5 L; (3) gas pressures encountered by the waste package do not exceed 0.36 MPa prior to mine closure. After this time, it is conceivable that stress on the canister could approach the lithostatic rock stresses; (4) maximum dose rates in the salt are < 1400 rads/h.

  18. Impact of transporting defense high-level waste to a geologic repository

    SciTech Connect

    Joy, D.S.; Shappert, L.B.; Boyle, J.W.

    1984-08-01

    This transportation study assumes that defense high-level waste is stored in three locations (the Savannah River, Hanford, and Idaho Falls plants) and may be disposed of in (1) a commercial repository or (2) a defense-only repository, either of which could be located at one of the five candidate sites; also documented is a preliminary analysis of the costs and risks of transporting defense high-level waste from the three storage sites to the five potential candidate repository sites. 17 references, 4 figures, 27 tables.

  19. Nuclear waste management

    SciTech Connect

    Frankel, D.R.

    1980-01-01

    Several recent congressional and executive proposals address the political problem posed by nuclear wastes. The proposals are divided into three categories on the basis of the degree of authority granted to state officials in siting decisions: those granting states a veto power, those providing for consultation with state officials during planning, and those leaving plenary authority in the hands of the Federal goverment. Legislative proposals are discussed under these categories. The most-balanced approach provides a formal role for state officials without granting the states an absolute veto. This solution provides a political outlet for local concern and ensures a wider range of views. It also avoids the problem, inherent in the state veto, of sacrificing the national interest in selecting the safest possible disposal site. 69 references.

  20. Predicting the Lifetimes of Nuclear Waste Containers

    NASA Astrophysics Data System (ADS)

    King, Fraser

    2014-03-01

    As for many aspects of the disposal of nuclear waste, the greatest challenge we have in the study of container materials is the prediction of the long-term performance over periods of tens to hundreds of thousands of years. Various methods have been used for predicting the lifetime of containers for the disposal of high-level waste or spent fuel in deep geological repositories. Both mechanical and corrosion-related failure mechanisms need to be considered, although until recently the interactions of mechanical and corrosion degradation modes have not been considered in detail. Failure from mechanical degradation modes has tended to be treated through suitable container design. In comparison, the inevitable loss of container integrity due to corrosion has been treated by developing specific corrosion models. The most important aspect, however, is to be able to justify the long-term predictions by demonstrating a mechanistic understanding of the various degradation modes.

  1. Characterizing the proposed geologic repository for high-level radioactive waste at Yucca Mountain, Nevada--hydrology and geochemistry

    USGS Publications Warehouse

    Stuckless, John S.; Levich, Robert A.

    2012-01-01

    This hydrology and geochemistry volume is a companion volume to the 2007 Geological Society of America Memoir 199, The Geology and Climatology of Yucca Mountain and Vicinity, Southern Nevada and California, edited by Stuckless and Levich. The work in both volumes was originally reported in the U.S. Department of Energy regulatory document Yucca Mountain Site Description, for the site characterization study of Yucca Mountain, Nevada, as the proposed U.S. geologic repository for high-level radioactive waste. The selection of Yucca Mountain resulted from a nationwide search and numerous committee studies during a period of more than 40 yr. The waste, largely from commercial nuclear power reactors and the government's nuclear weapons programs, is characterized by intense penetrating radiation and high heat production, and, therefore, it must be isolated from the biosphere for tens of thousands of years. The extensive, unique, and often innovative geoscience investigations conducted at Yucca Mountain for more than 20 yr make it one of the most thoroughly studied geologic features on Earth. The results of these investigations contribute extensive knowledge to the hydrologic and geochemical aspects of radioactive waste disposal in the unsaturated zone. The science, analyses, and interpretations are important not only to Yucca Mountain, but also to the assessment of other sites or alternative processes that may be considered for waste disposal in the future. Groundwater conditions, processes, and geochemistry, especially in combination with the heat from radionuclide decay, are integral to the ability of a repository to isolate waste. Hydrology and geochemistry are discussed here in chapters on unsaturated zone hydrology, saturated zone hydrology, paleohydrology, hydrochemistry, radionuclide transport, and thermally driven coupled processes affecting long-term waste isolation. This introductory chapter reviews some of the reasons for choosing to study Yucca Mountain as a

  2. Characterizing the proposed geologic repository for high-level radioactive waste at Yucca Mountain, Nevada: hydrology and geochemistry

    USGS Publications Warehouse

    Stuckless, John S.; Levich, Robert A.

    2012-01-01

    This hydrology and geochemistry volume is a companion volume to the 2007 Geological Society of America Memoir 199, The Geology and Climatology of Yucca Mountain and Vicinity, Southern Nevada and California, edited by Stuckless and Levich. The work in both volumes was originally reported in the U.S. Department of Energy regulatory document Yucca Mountain Site Description, for the site characterization study of Yucca Mountain, Nevada, as the proposed U.S. geologic repository for high-level radioactive waste. The selection of Yucca Mountain resulted from a nationwide search and numerous committee studies during a period of more than 40 yr. The waste, largely from commercial nuclear power reactors and the government's nuclear weapons programs, is characterized by intense penetrating radiation and high heat production, and, therefore, it must be isolated from the biosphere for tens of thousands of years. The extensive, unique, and often innovative geoscience investigations conducted at Yucca Mountain for more than 20 yr make it one of the most thoroughly studied geologic features on Earth. The results of these investigations contribute extensive knowledge to the hydrologic and geochemical aspects of radioactive waste disposal in the unsaturated zone. The science, analyses, and interpretations are important not only to Yucca Mountain, but also to the assessment of other sites or alternative processes that may be considered for waste disposal in the future. Groundwater conditions, processes, and geochemistry, especially in combination with the heat from radionuclide decay, are integral to the ability of a repository to isolate waste. Hydrology and geochemistry are discussed here in chapters on unsaturated zone hydrology, saturated zone hydrology, paleohydrology, hydrochemistry, radionuclide transport, and thermally driven coupled processes affecting long-term waste isolation. This introductory chapter reviews some of the reasons for choosing to study Yucca Mountain as a

  3. Continuous Improvement and the Safety Case for the Waste Isolation Pilot Plant Geologic Repository - 13467

    SciTech Connect

    Van Luik, Abraham; Patterson, Russell; Nelson, Roger; Leigh, Christi

    2013-07-01

    The Waste Isolation Pilot Plant (WIPP) is a geologic repository 2150 feet (650 m) below the surface of the Chihuahuan desert near Carlsbad, New Mexico. WIPP permanently disposes of transuranic waste from national defense programs. Every five years, the U.S. Department of Energy (DOE) submits an application to the U.S. Environmental Protection Agency (EPA) to request regulatory-compliance re-certification of the facility for another five years. Every ten years, DOE submits an application to the New Mexico Environment Department (NMED) for the renewal of its hazardous waste disposal permit. The content of the applications made by DOE to the EPA for re-certification, and to the NMED for permit-renewal, reflect any optimization changes made to the facility, with regulatory concurrence if warranted by the nature of the change. DOE points to such changes as evidence for its having taken seriously its 'continuous improvement' operations and management philosophy. Another opportunity for continuous improvement is to look at any delta that may exist between the re-certification and re-permitting cases for system safety and the consensus advice on the nature and content of a safety case as being developed and published by the Nuclear Energy Agency's Integration Group for the Safety Case (IGSC) expert group. DOE at WIPP, with the aid of its Science Advisor and teammate, Sandia National Laboratories, is in the process of discerning what can be done, in a reasonably paced and cost-conscious manner, to continually improve the case for repository safety that is being made to the two primary regulators on a recurring basis. This paper will discuss some aspects of that delta and potential paths forward to addressing them. (authors)

  4. Status of the Nevada Nuclear Waste Storage investigations

    SciTech Connect

    Lincoln, R. C.

    1982-01-01

    The Nevada Nuclear Waste Storage Investigations (NNWSI) are part of the National Waste Terminal Storage (NWTS) program being conducted by the Department of Energy. Within the NWTS program, the NNWSI is the component that focuses on siting evaluations on and near the Nevada Test Site (NTS). The objectives of the Nevada project include evaluating the suitability of a Test and Evaluation Facility (TEF) site on or near the NTS, evaluating the suitability of a commercial nuclear waste repository site on or near the NTS, and supporting the NWTS program with research that is uniquely possible at NTS. Current engineering studies suggest that TEF and repository surface facilities would need to be located on gently sloping alluvium east of Yucca Mountain. Access from surface facilities to underground waste emplacement areas would be by vertical shafts and horizontal drifts, or possibly by inclined adits. The current NNWSI schedule includes an exploratory shaft location and horizon recommendation in 12/82, with a start of exploratory shaft drilling in 9/83. Because of the complexities of horizon selection, it is possible that the exploratory shaft depth or horizon recommendation may involve the exploration of more than one horizon. Phase I of the exploratory shaft, determination of TEF site suitability, is currently scheduled for 7/85. Phase II of the exploratory shaft, determination of repository site suitability, is currently scheduled for 3/87. This schedule is consistent with the current NWTS TEF and repository site selection schedules.

  5. Preliminary risk benefit assessment for nuclear waste disposal in space

    NASA Technical Reports Server (NTRS)

    Rice, E. E.; Denning, R. S.; Friedlander, A. L.; Priest, C. C.

    1982-01-01

    This paper describes the recent work of the authors on the evaluation of health risk benefits of space disposal of nuclear waste. The paper describes a risk model approach that has been developed to estimate the non-recoverable, cumulative, expected radionuclide release to the earth's biosphere for different options of nuclear waste disposal in space. Risk estimates for the disposal of nuclear waste in a mined geologic repository and the short- and long-term risk estimates for space disposal were developed. The results showed that the preliminary estimates of space disposal risks are low, even with the estimated uncertainty bounds. If calculated release risks for mined geologic repositories remain as low as given by the U.S. DOE, and U.S. EPA requirements continue to be met, then no additional space disposal study effort in the U.S. is warranted at this time. If risks perceived by the public are significant in the acceptance of mined geologic repositories, then consideration of space disposal as a complement to the mined geologic repository is warranted.

  6. Intergovernmental complexity in nuclear waste disposal policy: The indeterminate role of local government

    SciTech Connect

    Herzik, E.B.; Mushkatel, A.H.

    1991-12-31

    Local governments play a critical, albeit often overlooked, role in nuclear waste disposal policymaking. The centrality of local governments in the policymaking process rests on the simple fact that impacts would be borne disproportionately by local jurisdictions hosting and immediately adjacent to waste disposal sites. This article focuses on the capacity of local jurisdictions in Southern and rural Nevada to absorb and support an undertaking as large and technically complex as the proposed high-level nuclear waste repository. The article also examines the perceptions of local government officials concerning a number of management and policy issues related to the construction and operation of the proposed waste repository.

  7. Geoscientific Site Evaluation Approach for Canada's Deep Geological Repository for Used Nuclear Fuel

    NASA Astrophysics Data System (ADS)

    Sanchez-Rico Castejon, M.; Hirschorn, S.; Ben Belfadhel, M.

    2015-12-01

    The Nuclear Waste Management Organization (NWMO) is responsible for implementing Adaptive Phased Management, the approach selected by the Government of Canada for long-term management of used nuclear fuel generated by Canadian nuclear reactors. The ultimate objective of APM is the centralized containment and isolation of Canada's used nuclear fuel in a Deep Geological Repository in a suitable crystalline or sedimentary rock formation. In May 2010, the NWMO published and initiated a nine-step site selection process to find an informed and willing community to host a deep geological repository for Canada's used nuclear fuel. The site selection process is designed to address a broad range of technical and social, economic and cultural factors. The site evaluation process includes three main technical evaluation steps: Initial Screenings; Preliminary Assessments; and Detailed Site Characterizations, to assess the suitability of candidate areas in a stepwise manner over a period of many years. By the end of 2012, twenty two communities had expressed interest in learning more about the project. As of July 2015, nine communities remain in the site selection process. To date (July 2015), NWMO has completed Initial Screenings for the 22 communities that expressed interest, and has completed the first phase of Preliminary Assessments (desktop) for 20 of the communities. Phase 2 of the Preliminary Assessments has been initiated in a number of communities, with field activities such as high-resolution airborne geophysical surveys and geological mapping. This paper describes the approach, methods and criteria being used to assess the geoscientific suitability of communities currently involved in the site selection process.

  8. Geochemistry and petrology of surface samples, six boreholes and brines from the Salton Sea geothermal field: A natural analog of a nuclear waste repository in salt: Report No. 3

    SciTech Connect

    Not Available

    1987-05-01

    Cuttings from six wells in the Salton Sea geothermal field, and rocks at outcrop that are correlative in age with those encountered at depth in the wells were analyzed in detail. Mineralogy, petrography, x-ray diffraction, electron microprobe, instrumental neutron activation analysis, fission track radiography, oxygen and stable carbon isotopic, uranium-thorium series disequilibrium, and fluid inclusion analyses are reported. Where fluids were being produced from wells, brine chemistry as well as stable isotope and uranium-thorium series analyses are reported. Particular attention has been paid to defining zones of fluid-rock interaction in which analyses of coexisting geothermal reservoir brine and hydrothermally altered sediments could be acquired. A wide span of temperatures, from surficial to greater than 300/degree/C, and salinities ranging from relatively dilute ground waters up to brines of 25 wt% total dissolved solids, span a range of environments that might be encountered in a waste repository in salt. Progressive hydrothermal alteration, mineral formation and element mobility are documented in the data presented. 52 refs., 25 figs., 49 tabs.

  9. Radioactive waste isolation in salt: peer review of Westinghouse Electric Corporation's report on reference conceptual designs for a repository waste package

    SciTech Connect

    Rote, D.M.; Hull, A.B.; Was, G.S.; Macdonald, D.D.; Wilde, B.E.; Russell, J.E.; Kruger, J.; Harrison, W.; Hambley, D.F.

    1985-10-01

    This report documents the findings of the peer panel constituted by Argonne National Laboratory to review Region A of Westinghouse Electric Corporation's report entitled Waste Package Reference Conceptual Designs for a Repository in Salt. The panel determined that the reviewed report does not provide reasonable assurance that US Nuclear Regulatory Commission (NRC) requirements for waste packages will be met by the proposed design. It also found that it is premature to call the design a ''reference design,'' or even a ''reference conceptual design.'' This review report provides guidance for the preparation of a more acceptable design document.

  10. Space disposal of nuclear wastes

    NASA Technical Reports Server (NTRS)

    Priest, C. C.; Nixon, R. F.; Rice, E. E.

    1980-01-01

    The DOE has been studying several options for nuclear waste disposal, among them space disposal, which NASA has been assessing. Attention is given to space disposal destinations noting that a circular heliocentric orbit about halfway between Earth and Venus is the reference option in space disposal studies. Discussion also covers the waste form, showing that parameters to be considered include high waste loading, high thermal conductivity, thermochemical stability, resistance to leaching, fabrication, resistance to oxidation and to thermal shock. Finally, the Space Shuttle nuclear waste disposal mission profile is presented.

  11. Prediction of radioactive waste glass durability by the hydration thermodynamic model: Application to saturated repository environments

    SciTech Connect

    Jantzen, C.M. ); Ramsey, W.G. . Dept. of Ceramic Engineering)

    1989-01-01

    The effects of groundwater chemistry on glass durability were examined using the hydration thermodynamic model. The relative durabilities of SiO{sub 2}, obsidians, basalts, nuclear waste glasses, medieval window glasses, and a frit glass were determined in tuffaceous groundwater, basaltic groundwater, WIPP-A brine, and Permian-A brine using the monolithic MCC-1 durability test. For all the groundwaters, the free energy of hydration, calculated from the glass composition and the final experimental pH, was linearly related to the logarithm of the measured silica concentration. The linear equation was identical to that observed previously for these glasses during MCC-1 testing in deionized water. In the groundwater-dominated MCC-1 experiments, the pH values for all the glasses tested appeared to be buffered by the groundwater-precipitate chemistry. The behavior of poorly durable glasses demonstrated that the silica release is a function of the ionic strength of the solution. The ionic strength, in turn, reflects the effect of the groundwater chemistry on the pH. Using the hydration thermodynamic model, nuclear waste glass durability in saturated repository environments can be predicted from the glass composition and the groundwater and the groundwater pH. 47 refs., 3 figs. 1 tab.

  12. Nuclear waste solidification

    DOEpatents

    Bjorklund, William J.

    1977-01-01

    High level liquid waste solidification is achieved on a continuous basis by atomizing the liquid waste and introducing the atomized liquid waste into a reaction chamber including a fluidized, heated inert bed to effect calcination of the atomized waste and removal of the calcined waste by overflow removal and by attrition and elutriation from the reaction chamber, and feeding additional inert bed particles to the fluidized bed to maintain the inert bed composition.

  13. Materials Science of High-Level Nuclear Waste Immobilization

    SciTech Connect

    Weber, William J.; Navrotsky, Alexandra; Stefanovsky, S. V.; Vance, E. R.; Vernaz, Etienne Y.

    2009-01-09

    With the increasing demand for the development of more nuclear power comes the responsibility to address the technical challenges of immobilizing high-level nuclear wastes in stable solid forms for interim storage or disposition in geologic repositories. The immobilization of high-level nuclear wastes has been an active area of research and development for over 50 years. Borosilicate glasses and complex ceramic composites have been developed to meet many technical challenges and current needs, although regulatory issues, which vary widely from country to country, have yet to be resolved. Cooperative international programs to develop advanced proliferation-resistant nuclear technologies to close the nuclear fuel cycle and increase the efficiency of nuclear energy production might create new separation waste streams that could demand new concepts and materials for nuclear waste immobilization. This article reviews the current state-of-the-art understanding regarding the materials science of glasses and ceramics for the immobilization of high-level nuclear waste and excess nuclear materials and discusses approaches to address new waste streams.

  14. The future of high-level nuclear waste disposal, state sovereignty and the tenth amendment: Nevada v. Watkins

    SciTech Connect

    Swazo, S.

    1996-12-01

    The federal government`s monopoly over America`s nuclear energy production began during World War II with the birth of the Atomic Age. During the next thirty years, nuclear waste inventories increased with minor congressional concern. In the early 1970s, the need for federal legislation to address problems surrounding nuclear waste regulation, along with federal efforts to address these problems, became critical. Previous federal efforts had completely failed to address nuclear waste disposal. In 1982, Congress enacted the Nuclear Waste Policy Act (NWPA) to deal with issues of nuclear waste management and disposal, and to set an agenda for the development of two national high-level nuclear waste repositories. This article discusses the legal challenge to the NWPA in the Nevada v. Watkins case. This case illustrates the federalism problems faced by the federal government in trying to site the nation`s only high-level nuclear waste repository within a single state.

  15. Factors controlling radionuclide transport behavior in a generic geological radioactive waste repository

    NASA Astrophysics Data System (ADS)

    Bianchi, M.; Liu, H.; Birkholzer, J. T.

    2013-12-01

    One of the main challenges in designing a geological repository for high-level nuclear waste is the assessment of postclosure safety, which involves the long-term ability of the engineered system and the geological host formation to contain and delay the leakage of radionuclides toward the biosphere. A correct assessment requires detailed knowledge of the factors controlling radionuclide transport in the different components of the geological disposal system. For instance, molecular diffusion, which is considered the dominant transport mechanism in low-permeable geological formations, may be influenced by the heterogeneity of the diffusive parameters and by electrochemical processes. Likewise, the prevalence of advective transport in the near-field excavation damaged zone (EDZ) may be controlled by the hydrogeological conditions in the host formation, as well as by hydrogeological and geometrical properties. In this study, we performed two-dimensional numerical simulations of groundwater flow and radionuclide transport to study the influence of several factors on the prevailing transport mechanism (i.e., advection or molecular diffusion) in the different components of a geological nuclear waste repository system. Particular attention was given to the excavation damaged zone (EDZ) around the repository tunnels and access shaft, which was modeled as a single effective continuum as well as with the dual-porosity approach. We considered different hydrogeological and geometrical factors, including the ambient hydraulic gradient, the presence of groundwater pressure anomalies, and the thickness of the EDZ and its hydraulic properties. By comparing simulation results, we show that transport behavior and the role of the EDZ as a preferential flow path for radionuclide transport is most sensitive to the hydrogeological conditions in the host rock. When the hydraulic gradient in the host rock is reduced by a factor of 5 from the unit value, we observe a significant reduction

  16. Approaches to confirmatory testing of a groundwater flow model for sparsely fractured crystalline rock, exemplified by data from the proposed high-level nuclear waste repository site at Forsmark, Sweden

    NASA Astrophysics Data System (ADS)

    Follin, Sven; Hartley, Lee

    2014-03-01

    The Svensk Kärnbränslehantering AB (SKB) has proposed the Forsmark site as a future repository for spent high-level nuclear fuel, involving disposal at about 470 m depth in sparsely fractured crystalline bedrock. An essential part of the completed inter-disciplinary site investigation was to develop an integrated account of the site and its regional setting, including the current state of the geosphere and the biosphere as well as natural processes affecting long-term evolution. First, this report recollects the integrated understanding and some key hydraulic characteristics of the crystalline bedrock at Forsmark along with a description of the flow model set-up and the methodology used for paleoclimatic flow modeling. Second, the protocol used for site-scale groundwater flow and solute transport modeling is demonstrated. In order to conduct a quantitative assessment of groundwater flow paths at Forsmark, the standard guide for groundwater flow modeling was elaborated on, to support both discrete and porous media flow approaches. In total, four independent types of data were used to confirm that the final groundwater flow model for the crystalline bedrock was representative of site conditions.

  17. A transmissivity model for deformation zones in fractured crystalline rock and its possible correlation to in situ stress at the proposed high-level nuclear waste repository site at Forsmark, Sweden

    NASA Astrophysics Data System (ADS)

    Follin, Sven; Stigsson, Martin

    2014-03-01

    The Forsmark site was recently proposed by the Svensk Kärnbränslehantering AB (SKB) to serve as the potential site for construction of a future geological repository for spent high-level nuclear fuel at about 470 m depth in fractured crystalline rock. The considerations included, among other things, distance from regionally significant deformation zones with highly strained rock, lithological homogeneity, low hydraulic conductivity, groundwater salinity with an acceptable range, and lack of potential mineral resources. This report describes the calculation of transmissivity of deduced deformation zones at Forsmark and the transmissivity model used in the regional groundwater flow modeling carried out in support of the integrated site description. Besides significant decrease with increasing depth (more than four orders of magnitude over a depth of about 1 km), the calculated transmissivity values also reveal considerable spatial variability along the strikes of the zones, i.e. lateral heterogeneity (more than two orders of magnitude). A hydro-mechanical coupling is discussed, based on presented models for the tectonic evolution and the principal stress tensor. Tentatively, laboratory-scale relationships developed from normal stress experiments on a single fracture in crystalline rock can be used to estimate the maximum values of transmissivity of deduced deformation zones at Forsmark.

  18. Peat: a natural repository for low-level radioactive waste

    SciTech Connect

    Thomas, E.D.

    1985-12-01

    A study has been initiated to evaluate the possibility of using peat as a natural repository for the disposal of low-level radioactive waste. One aspect of this study was to determine the retentive properties of the peat through measurements of the distribution coefficients (K/sub d/) for Am-241, Ru-106, Cs-137, Co-57, and Sr-85 in two layers of mountain top peat bogs from Lefgren's, NY, and Spruce Flats, PA. These K/sub d/ values were then compared to literature values of various sediment/water systems at similar environmental conditions. Am-241, Ru-106, Co-57, and Sr-85 attained distribution coefficients in the organic rich layers of the bogs two orders of magnitude greater than those obtained previously at pH 4.0. Although, the Cs-137 sorbed strongly to the inorganic rich layer of the Spruce Flats, PA, bog, the K/sub d/ values obtained for this isotope were, again, comparable or higher than those reported previously at pH 4.0, indicating the greater retentive properties of the peat. A chromatographic ''theoretical plate'' model was used to describe the field migration of Cs-137. The advection and diffusion coefficients were higher in the Lefgren's Bog, NY, than those obtained for the Spruce Flats Bog, PA. These field data were substantiated by the lower Cs-137 K/sub d/ values determined in the laboratory for the Lefgren's Bog, NY, compared to the Spruce Flats Bog. Although this model gave a good indication of the field migration, it neglected the process of sorption as defined by the sorption isotherm. Based on the time series data on distribution ratio measurements, a Cameron-Klute type of sorption isotherm was indicated, with rapid equilibrium initially superimposed onto a slower first order linear reversible equilibrium. This sorption isotherm can then be used in the final form of a model to describe the migration of radionuclides in a peat bog. 19 refs., 15 figs., 10 tabs.

  19. Canada's Deep Geological Repository For Used Nuclear Fuel -The Geoscientific Site Evaluation Process

    NASA Astrophysics Data System (ADS)

    Hirschorn, S.; Ben Belfadhel, M.; Blyth, A.; DesRoches, A. J.; McKelvie, J. R. M.; Parmenter, A.; Sanchez-Rico Castejon, M.; Urrutia-Bustos, A.; Vorauer, A.

    2014-12-01

    The Nuclear Waste Management Organization (NWMO) is responsible for implementing Adaptive Phased Management, the approach selected by the Government of Canada for long-term management of used nuclear fuel generated by Canadian nuclear reactors. In May 2010, the NWMO published and initiated a nine-step site selection process to find an informed and willing community to host a deep geological repository for Canada's used nuclear fuel. The site selection process is designed to address a broad range of technical and social, economic and cultural factors. The suitability of candidate areas will be assessed in a stepwise manner over a period of many years and include three main steps: Initial Screenings; Preliminary Assessments; and Detailed Site Characterizations. The Preliminary Assessment is conducted in two phases. NWMO has completed Phase 1 preliminary assessments for the first eight communities that entered into this step. While the Phase 1 desktop geoscientific assessments showed that each of the eight communities contains general areas that have the potential to satisfy the geoscientific safety requirements for hosting a deep geological repository, the assessment identified varying degrees of geoscientific complexity and uncertainty between communities, reflecting their different geological settings and structural histories. Phase 2 activities will include a sequence of high-resolution airborne geophysical surveys and focused geological field mapping to ground-truth lithology and structural features, followed by limited deep borehole drilling and testing. These activities will further evaluate the site's ability to meet the safety functions that a site would need to ultimately satisfy in order to be considered suitable. This paper provides an update on the site evaluation process and describes the approach, methods and criteria that are being used to conduct the geoscientific Preliminary Assessments.

  20. Biogeochemical Changes at Early Stage After the Closure of Radioactive Waste Geological Repository in South Korea

    SciTech Connect

    Choung, Sungwook; Um, Wooyong; Choi, Seho; Francis, Arokiasamy J.; Kim, Sungpyo; Park, Jin beak; Kim, Suk-Hoon

    2014-09-01

    Permanent disposal of low- and intermediate-level radioactive wastes in the subterranean environment has been the preferred method of many countries, including Korea. A safety issue after the closure of a geological repository is that biodegradation of organic materials due to microbial activities generates gases that lead to overpressure of the waste containers in the repository and its disintegration with the release of radionuclides. As part of an ongoing large-scale in situ experiment using organic wastes and groundwater to simulate geological radioactive waste repository conditions, we investigated the geochemical alteration and microbial activities at an early stage (~63 days) intended to be representative of the initial period after repository closure. The increased numbers of both aerobes and facultative anaerobes in waste effluents indicate that oxygen content could be the most significant parameter to control biogeochemical conditions at very early periods of reaction (<35 days). Accordingly, the values of dissolved oxygen and redox potential were decreased. The activation of anaerobes after 35 days was supported by the increased concentration to ~50 mg L-1 of ethanol. These results suggest that the biogeochemical conditions were rapidly altered to more reducing and anaerobic conditions within the initial 2 months after repository closure. Although no gases were detected during the study, activated anaerobic microbes will play more important role in gas generation over the long term.

  1. Scientific Solutions to Nuclear Waste Environmental Challenges

    SciTech Connect

    Johnson, Bradley R.

    2014-01-30

    of time it takes for one-half of the material to undergo radioactive decay.) In general, the ideal material would need to be durable for approximately 10 half-lives to allow the activity to decay to negligible levels. However, the potential health effects of each radionuclide vary depending on what type of radiation is emitted, the energy of that emission, and the susceptibility for the human body to accumulate and concentrate that particular element. Consequently, actual standards tend to be based on limiting the dose (energy deposited per unit mass) that is introduced into the environment. The Environmental Protection Agency (EPA) has the responsibility to establish standards for nuclear waste disposal to protect the health and safety of the public. For example, the Energy Policy Act of 1992 directed the EPA to establish radiation protection standards for the Yucca Mountain geologic repository for nuclear wastes. The standards for Yucca Mountain were promulgated in 2008, and limit the dose to 15 millirem per year for the first 10,000 years, and 100 milirem per year between 10,000 years and 1 million years (40 CFR Part 197; http://www.epa.gov/radiation/yucca/2008factsheet.html). So, the challenge is two-fold: (1) develop a material (a waste form) that is capable of immobilizing the waste over geologic time scales, and (2) develop a process to convert the radioactive sludge in the tanks into this durable waste form material. Glass: Hard, durable, inert, and with infinite chemical versatility Molten glass is a powerful solvent liquid, which can be designed to dissolve almost anything. When solidified, it can be one of the most chemically inert substances known to man. Nature's most famous analogue to glass is obsidian, a vitreous product of volcanic activity; formations over 17 million years old have been found. Archaeologists have found man-made glass specimens that are five thousand years old.

  2. Chemical durability of glass containing SRP waste: leachability characteristics, protective layer formation, and repository system interactions

    SciTech Connect

    Wicks, G G; Robnett, B M; Rankin, W D

    1982-01-01

    The Repository Systems Program at Savannah River consists of the following elements: (a) static repository tests, (b) slow flow groundwater tests, (c) dynamic leaching experiments, (d) long term leaching tests, and (e) in situ experiments. The scouting tests performed in the static repository program are summarized and a new dynamic leaching concept is introduced in this paper. Abbreviated MCC-1 static leaching tests were used in this static repository program. The tests were conducted at 90/sup 0/C for 7 days with deionized water as well as repository groundwaters as leachants. The static repository program consisted of three phases. Phase 1 of the study evaluated the leachability of SRP waste glass leached in the presence of salt, basalt, shale, granite, and tuff at three different ratios of surface areas of sample to volume of leachant (SA/V). These data were then compared to tests on similar glasses leached in the absence of rock. The second phase of this program evaluated the effects of five simulated groundwaters on the leachability of waste glass both with and without host rock present and compared these results to glass leached by deionized water. The groundwaters included many minor as well as major constituents. The third and final phase of the program evaluated waste glass leachability as a function of tests conducted in the presence of candidate canister and overpack metals, backfill mixtures, and five complete package systems. The sample matrices are given in Table 2 and the data are summarized.

  3. Workshop on fundamental geochemistry needs for nuclear waste isolation

    SciTech Connect

    Heiken, J.H.

    1985-09-01

    In their deliberations, workshop participants did not attempt to incorporate the constraints that the 1982 National Nuclear Waste Management Policy Act placed upon the site-specific investigations. In particular, there was no attempt to (1) identify the research areas that apply most strongly to a particular potential repository site, (2) identify the chronological time when the necessary data or knowledge could be available, or (3) include a sensitivity analysis to prioritize and limit data needs. The workshop participants felt these are the purview of the site-specific investigations; the purpose of the workshop was to discuss the generic geochemistry research needs for a nuclear waste repository among as broad spectrum of individual scientists as possible and to develop a consensus of what geochemical information is important and why.

  4. Report on Intact and Degraded Criticality for Selected Plutonium Waste Forms in a Geologic Repository, Volume I: MOX SNF

    SciTech Connect

    J.A. McClure

    1998-09-21

    As part of the plutonium waste form development and down-select process, repository analyses have been conducted to evaluate the long-term performance of these forms for repository acceptance. Intact and degraded mode criticality analysis of the mixed oxide (MOX) spent fuel is presented in Volume I, while Volume II presents the evaluations of the waste form containing plutonium immobilized in a ceramic matrix. Although the ceramic immobilization development program is ongoing, and refinements are still being developed and evaluated, this analysis provides value through quick feed-back to this development process, and as preparation for the analysis that will be conducted starting in fiscal year (FY) 1999 in support of the License Application. While no MOX fuel has been generated in the United States using weapons-usable plutonium, Oak Ridge National Laboratory (ORNL) has conducted calculations on Westinghouse-type reactors to determine the expected characteristics of such a fuel. These spent nuclear fuel (SNF) characteristics have been used to determine the long-term potential for criticality in a repository environment. In all instances the methodology and scenarios used in these analyses are compatible with those developed and used for Commercial Spent Nuclear Fuel (CSNF) and Defense High Level Waste (DHLW), as tailored for the particular characteristics of the waste forms. This provides a common basis for comparison of the results. This analysis utilizes dissolution, solubility, and thermodynamic data that are currently available. Additional data on long-term behavior is being developed, and later analyses (FY 99) to support the License Application will use the very latest information that has been generated. Ranges of parameter values are considered to reflect sensitivity to uncertainty. Most of the analysis is focused on those parameter values that produce the worst case results, so that potential licensing issues can be identified.

  5. A program to assess microbial impacts on nuclear waste containment

    SciTech Connect

    Horn, J.; Meike, A.

    1996-02-20

    In this paper we discuss aspects of a comprehensive program to identify and bound potential effects of microorganisms on long-term nuclear waste containment, using as examples, studies conducted within the Yucca Mountain Project. A comprehensive program has been formulated which cuts across standard disciplinary lines to address the specific concerns of microbial activity in a radioactive waste repository. Collectively, this program provides bounding parameters of microbial activities that modify the ambient geochemistry and hydrology, modify corrosion rates, and transport and transform radionuclides under conditions expected to be encountered after geological waste emplacement. This program is intended to provide microbial reaction rates and bounding conditions in a form that can be integrated into existing chemical and hydrological models. The inclusion of microbial effects will allow those models to more accurately assess long term repository integrity.

  6. Radiological Aspects of Deep-Burn Fusion-Fission Hybrid Waste in a Repository

    SciTech Connect

    Shaw, H F; Blink, J A; Farmer, J C; Karmer, K J; Latkowski, J F; Zhao, P

    2008-11-25

    The quantity, radioactivity, and isotopic characteristics of the spent fission fuel from a hybrid fusion-fission system capable of extremely high burnups are described. The waste generally has higher activity per unit mass of heavy metal, but much lower activity per unit energy generated. The very long-term radioactivity is dominated by fission products. Simple scaling calculations suggest that the dose from a repository containing such waste would be dominated by {sup 129}I, {sup 135}Cs, and {sup 242}Pu. Use of such a system for generating energy would greatly reduce the need for repository capacity.

  7. Restoration of areas disturbed by site studies for a mined commercial radioactive waste repository: The Basalt Waste Isolation Project (BWIP)

    SciTech Connect

    Brandt, C.A.; Rickard, W.H. Jr.; Biehert, R.W.; Newell, R.L.; Page, T.L.

    1989-01-01

    The Basalt Waste Isolation Project (BWIP) was undertaken to environmentally characterize a portion of the US Department of Energy's Hanford Site in Washington State as a potential host for the nation's first mined commercial nuclear waste repository. Studies were terminated by Congress in 1987. Between 1976 and 1987, 72 areas located across the Hanford Site were disturbed by the BWIP. These areas include borehole pads, a large Exploratory Shaft Facility, and the Near Surface Test Facility. Most boreholes were cleared of vegetation, leveled, and stabilized with a thick layer of compacted pit-run gravel and sand. The Near Surface Test Facility consists of three mined adits, a rock-spoils bench, and numerous support facilities. Restoration began in 1988 with the objective of returning sites to pre-existing conditions using native species. The Hanford Site retains some of the last remnants of the shrub-steppe ecosystem in Washington. The primary constraints to restoring native vegetation at Hanford are low precipitation and the presence of cheatgrass, an extremely capable alien competitor. 5 figs.

  8. Method for storing spent nuclear fuel in repositories

    DOEpatents

    Schweitzer, Donald G.; Sastre, Cesar; Winsche, Warren

    1981-01-01

    A method for storing radioactive spent fuel in repositories containing sulfur as the storage medium is disclosed. Sulfur is non-corrosive and not subject to radiation damage. Thus, storage periods of up to 100 years are possible.

  9. Method for storing spent nuclear fuel in repositories

    DOEpatents

    Schweitzer, D.G.; Sastre, C.; Winsche, W.

    A method for storing radioactive spent fuel in repositories containing sulfur as the storage medium is disclosed. Sulfur is non-corrosive and not subject to radiation damage. Thus, storage periods of up to 100 years are possible.

  10. Nuclear hazardous waste cost control management

    SciTech Connect

    Selg, R.A.

    1991-05-09

    The effects of the waste content of glass waste forms on Savannah River high-level waste disposal costs are currently under study to adjust the glass frit content to optimize the glass waste loadings and therefore significantly reduce the overall waste disposal cost. Changes in waste content affect onsite Defense Waste Changes in waste contents affect onsite Defense Waste Processing Facility (DWPF) costs as well as offsite shipping and repository emplacement charges. A nominal 1% increase over the 28 wt% waste loading of DWPF glass would reduce disposal costs by about $50 million for Savannah River wastes generated to the year 2000. Optimization of the glass waste forms to be produced in the SWPF is being supported by economic evaluations of the impact of the forms on waste disposal costs. Glass compositions are specified for acceptable melt processing and durability characteristics, with economic effects tracked by the number of waste canisters produced. This paper presents an evaluation of the effects of variations in waste content of the glass waste forms on the overall cost of the disposal, including offsite shipment and repository emplacement, of the Savannah River high-level wastes.

  11. Methods of calculating the post-closure performance of high-level waste repositories

    SciTech Connect

    Ross, B.

    1989-02-01

    This report is intended as an overview of post-closure performance assessment methods for high-level radioactive waste repositories and is designed to give the reader a broad sense of the state of the art of this technology. As described here, ''the state of the art'' includes only what has been reported in report, journal, and conference proceedings literature through August 1987. There is a very large literature on the performance of high-level waste repositories. In order to make a review of this breadth manageable, its scope must be carefully defined. The essential principle followed is that only methods of calculating the long-term performance of waste repositories are described. The report is organized to reflect, in a generalized way, the logical order to steps that would be taken in a typical performance assessment. Chapter 2 describes ways of identifying scenarios and estimating their probabilities. Chapter 3 presents models used to determine the physical and chemical environment of a repository, including models of heat transfer, radiation, geochemistry, rock mechanics, brine migration, radiation effects on chemistry, and coupled processes. The next two chapters address the performance of specific barriers to release of radioactivity. Chapter 4 treats engineered barriers, including containers, waste forms, backfills around waste packages, shaft and borehole seals, and repository design features. Chapter 5 discusses natural barriers, including ground water systems and stability of salt formations. The final chapters address optics of general applicability to performance assessment models. Methods of sensitivity and uncertainty analysis are described in Chapter 6, and natural analogues of repositories are treated in Chapter 7. 473 refs., 19 figs., 2 tabs.

  12. Yucca Mountain repository approved

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    At a quiet White House ceremony on 23 July, U.S. President George W. Bush signed into law House Joint Resolution 87, which approves the site at Yucca Mountain, Nevada, for the development of a repository for disposing of high-level radioactive waste and spent nuclear fuel.White House spokesman Ari Fleischer called the signing “an important step forward on the way to a comprehensive policy for dealing with our nation's nuclear waste.”

  13. Report to Congress on the potential use of lead in the waste packages for a geologic repository at Yucca Mountain, Nevada

    SciTech Connect

    1989-12-01

    In the Report of the Senate Committee on Appropriations accompanying the Energy and Water Appropriation Act for 1989, the Committee directed the Department of Energy (DOE) to evaluate the use of lead in the waste packages to be used in geologic repositories for spent nuclear fuel and high-level waste. The evaluation that was performed in response to this directive is presented in this report. This evaluation was based largely on a review of the technical literature on the behavior of lead, reports of work conducted in other countries, and work performed for the waste-management program being conducted by the DOE. The initial evaluation was limited to the potential use of lead in the packages to be used in the repository. Also, the focus of this report is post closure performance and not on retrievability and handling aspects of the waste package. 100 refs., 8 figs., 15 tabs.

  14. Grappling with nuclear waste

    SciTech Connect

    Nair, B.R.

    1989-05-01

    The Waste Isolation Pilot Plant (WIPP) being constructed in the bedded salt formations near Carlsbad, N.M., is intended to demonstrate the safe disposal of transuranic wastes generated by U.S. defense programs. Both contact- and remote-handled transuranic wastes will be handled at WIPP; this article is only concerned with the latter, which is placed in horizontal boreholes. Since all deposited transuranic waste must be retrievable during the initial five-year operating period, the boreholes have steel sleeves that withstand salt lithostatic pressure to ease retrieval. If retrieval is not required during this demonstration period, waste deposited later does not have to be retrievable. The horizontal emplacement and retrieval equipment was designed and fabricated especially for the waste packages. The equipment had to meet many design, operational, and safety requirements. In addition to the structural sturdiness and power to support, position, and align massive loads (up to 35 tonnes) with a high degree of precision, it needs a sophisticated control system that permits foolproof operation in only one unique sequence.

  15. Salt Repository Project: Waste Package Program (WPP) modeling activiteis: FY 1984 annual report

    SciTech Connect

    Kuhn, W.L.; Simonson, S.A.; Pulsipher, B.A.

    1987-03-01

    The Pacific Northwest Laboratory (PNL) is supporting the US Department of Energy's (DOE) Salt Repository Project (SRP) through its Waste Package Program (WPP). During FY 1984, the WPP continued its program of waste package component development and interactions testing and application of the resulting data base to develop predictive models describing waste package degradation and radionuclide release. Within the WPP, the Modeling Task (Task 04 during FY 1984) was conducted to interpret the tests in such a way that scientifically defensible models can be developed for use in qualification of the waste package.

  16. Microbiology of formation waters from the deep repository of liquid radioactive wastes Severnyi.

    PubMed

    Nazina, Tamara N; Kosareva, Inessa M; Petrunyaka, Vladimir V; Savushkina, Margarita K; Kudriavtsev, Evgeniy G; Lebedev, Valeriy A; Ahunov, Viktor D; Revenko, Yuriy A; Khafizov, Robert R; Osipov, George A; Belyaev, Sergey S; Ivanov, Mikhail V

    2004-07-01

    The presence, diversity, and geochemical activity of microorganisms in the Severnyi repository of liquid radioactive wastes were studied. Cultivable anaerobic denitrifiers, fermenters, sulfate-reducers, and methanogens were found in water samples from a depth of 162-405 m below sea level. Subsurface microorganisms produced methane from [2-(14)C]acetate and [(14)C]CO(2), formed hydrogen sulfide from Na(2) (35)SO(4), and reduced nitrate to dinitrogen in medium with acetate. The cell numbers of all studied groups of microorganisms and rates of anaerobic processes were higher in the zone of dispersion of radioactive wastes. Microbial communities present in the repository were able to utilise a wide range of organic and inorganic compounds and components of waste (acetate, nitrate, and sulfate) both aerobically and anaerobically. Bacterial production of gases may result in a local increase of the pressure in the repository and consequent discharge of wastes onto the surface. Microorganisms can indirectly decrease the mobility of radionuclides due to consumption of oxygen and production of sulfide, which favours deposition of metals. These results show the necessity of long-term microbiological and radiochemical monitoring of the repository.

  17. State of Nevada, Agency for Nuclear Projects/Nuclear Waste Project Office narrative report, January 1--June 30, 1991

    SciTech Connect

    1996-08-01

    The Agency for Nuclear Projects/Nuclear Waste Project Office (NWPO) is the State of Nevada agency designated by State law to monitor and oversee US Department of Energy (DOE) activities relative to the possible siting, construction, operation and closure of a high-level nuclear waste repository at Yucca Mountain and to carry out the State of Nevada`s responsibilities under the Nuclear Waste Policy Act of 1982. During the reporting period the NWPO continued to work toward the five objectives designed to implement the Agency`s oversight responsibilities. (1) Assure that the health and safety of Nevada`s citizens are adequately protected with regard to any federal high-level radioactive waste program within the State. (2) Take the responsibilities and perform the duties of the State of Nevada as described in the Nuclear Waste Policy Act of 1982 (Public Law 97-425) and the Nuclear Waste Policy Amendments Act of 1987. (3) Advise the Governor, the State Commission on Nuclear Projects and the Nevada State Legislature on matters concerning the potential disposal of high-level radioactive waste in the State. (4) Work closely and consult with affected local governments and State agencies. (5) Monitor and evaluate federal planning and activities regarding high-level radioactive waste disposal. Plan and conduct independent State studies regarding the proposed repository.

  18. Safety aspects of nuclear waste disposal in space

    NASA Technical Reports Server (NTRS)

    Rice, E. E.; Edgecombe, D. S.; Compton, P. R.

    1981-01-01

    Safety issues involved in the disposal of nuclear wastes in space as a complement to mined geologic repositories are examined as part of an assessment of the feasibility of nuclear waste disposal in space. General safety guidelines for space disposal developed in the areas of radiation exposure and shielding, containment, accident environments, criticality, post-accident recovery, monitoring systems and isolation are presented for a nuclear waste disposal in space mission employing conventional space technology such as the Space Shuttle. The current reference concept under consideration by NASA and DOE is then examined in detail, with attention given to the waste source and mix, the waste form, waste processing and payload fabrication, shipping casks and ground transport vehicles, launch site operations and facilities, Shuttle-derived launch vehicle, orbit transfer vehicle, orbital operations and space destination, and the system safety aspects of the concept are discussed for each component. It is pointed out that future work remains in the development of an improved basis for the safety guidelines and the determination of the possible benefits and costs of the space disposal option for nuclear wastes.

  19. Radioactive waste isolation in salt: peer review of Office of Nuclear Waste Isolation's Socioeconomic Program Plan

    SciTech Connect

    Winter, R.; Fenster, D.; O'Hare, M.; Zillman, D.; Harrison, W.; Tisue, M.

    1984-07-01

    The following recommendations have been abstracted from the body of this report. The Office of Nuclear Waste Isolation's Socioeconomic Program Plan for the Establishment of Mined Geologic Repositories to Isolate Nuclear Waste should be modified to: (1) encourage active public participation in the decision-making processes leading to repository site selection; (2) clearly define mechanisms for incorporating the concerns of local residents, state and local governments, and other potentially interested parties into the early stages of the site selection process. In addition, the Office of Nuclear Waste Isolation should carefully review the overall role that these persons and groups, including local pressure groups organized in the face of potential repository development, will play in the siting process; (3) place significantly greater emphasis on using primary socioeconomic data during the site selection process, reversing the current overemphasis on secondary data collection, description of socioeconomic conditions at potential locations, and development of analytical methodologies; (4) include additional approaches to solving socioeconomic problems. For example, a reluctance to acknowledge that solutions to socioeconomic problems need to be found jointly with interested parties is evident in the plan; (5) recognize that mitigation mechanisms other than compensation and incentives may be effective; (6) as soon as potential sites are identified, the US Department of Energy (DOE) should begin discussing impact mitigation agreements with local officials and other interested parties; and (7) comply fully with the pertinent provisions of NWPA.

  20. Corrosion of Nuclear Fuel Inside a Failed Copper Nuclear Waste Container

    SciTech Connect

    Broczkowski, Michael E.; Goldik, Jonathan S.; Santos, Billy G.; Noel, James J.; Shoesmith, David

    2007-07-01

    Canada's Nuclear Waste Management Organization has recommended to the Canadian federal government an adaptive phased management approach to the long-term management of used nuclear fuel. This approach includes isolation in a deep geologic repository. In such a repository, the fuel would be sealed inside a carbon steel-lined copper container. To assist the development of performance assessment models studies of fuel behaviour inside a failed waste container are underway. Using an iterative modeling and experimental approach, the important features and processes that determine fuel behaviour have been identified and studied. These features and processes are discussed and the results of studies to elucidate specific mechanisms and determine important parameter values summarized. (authors)

  1. The Public and Nuclear Waste Management.

    ERIC Educational Resources Information Center

    Zinberg, Dorothy

    1979-01-01

    Discusses the public's negative attitude towards nuclear energy development. Explains the perceptions for the nuclear waste disposal problem, and the concern for the protection of the environment. (GA)

  2. Calculation of Upper Subcritical Limits for Nuclear Criticality in a Repository

    SciTech Connect

    J.W. Pegram

    1998-07-29

    The purpose of this document is to present the methodology to be used for development of the Subcritical Limit (SL) for post closure conditions for the Yucca Mountain repository. The SL is a value based on a set of benchmark criticality multiplier, k{sub eff} results that are outputs of the MCNP calculation method. This SL accounts for calculational biases and associated uncertainties resulting from the use of MCNP as the method of assessing k{sub eff}. The context for an SL estimate include the range of applicability (based on the set of MCNP results) and the type of SL required for the application at hand. This document will include illustrative calculations for each of three approaches. The data sets used for the example calculations are identified in Section 5.1. These represent three waste categories, and SLs for each of these sets of experiments will be computed in this document. Future MCNP data sets will be analyzed using the methods discussed here. The treatment of the biases evaluated on sets of k{sub eff} results via MCNP is statistical in nature. This document does not address additional non-statistical contributions to the bias margin, acknowledging that regulatory requirements may impose additional administrative penalties. Potentially, there are other biases or margins that should be accounted for when assessing criticality (k{sub eff}). Only aspects of the bias as determined using the stated assumptions and benchmark critical data sets will be included in the methods and sample calculations in this document. The set of benchmark experiments used in the validation of the computational system should be representative of the composition, configuration, and nuclear characteristics for the application at hand. In this work, a range of critical experiments will be the basis of establishing the SL for three categories of waste types that will be in the repository. The ultimate purpose of this document is to present methods that will effectively

  3. Nuclear waste package materials testing report: basaltic and tuffaceous environments

    SciTech Connect

    Bradley, D.J.; Coles, D.G.; Hodges, F.N.; McVay, G.L.; Westerman, R.E.

    1983-03-01

    The disposal of high-level nuclear wastes in underground repositories in the continental United States requires the development of a waste package that will contain radionuclides for a time period commensurate with performance criteria, which may be up to 1000 years. This report addresses materials testing in support of a waste package for a basalt (Hanford, Washington) or a tuff (Nevada Test Site) repository. The materials investigated in this testing effort were: sodium and calcium bentonites and mixtures with sand or basalt as a backfill; iron and titanium-based alloys as structural barriers; and borosilicate waste glass PNL 76-68 as a waste form. The testing also incorporated site-specific rock media and ground waters: Reference Umtanum Entablature-1 basalt and reference basalt ground water, Bullfrog tuff and NTS J-13 well water. The results of the testing are discussed in four major categories: Backfill Materials: emphasizing water migration, radionuclide migration, physical property and long-term stability studies. Structural Barriers: emphasizing uniform corrosion, irradiation-corrosion, and environmental-mechanical testing. Waste Form Release Characteristics: emphasizing ground water, sample surface area/solution volume ratio, and gamma radiolysis effects. Component Compatibility: emphasizing solution/rock, glass/rock, glass/structural barrier, and glass/backfill interaction tests. This area also includes sensitivity testing to determine primary parameters to be studied, and the results of systems tests where more than two waste package components were combined during a single test.

  4. Application of rock melting to construction of storage holes for nuclear waste

    SciTech Connect

    Neudecker, J.W. Jr.

    1988-12-31

    Rock melting technology can provide in-situ glass liners in nuclear waste package emplacement holes to reduce permeability and increase borehole stability. Reduction of permeability would reduce the time and probability of groundwater contacting the waste packages. Increasing the stability of the storage boreholes would enhance the retrievability of the nuclear waste packages. The rock melting hole forming technology has already been tested in volcanic tuff similar to the geology at the proposed nuclear waste repository at Yucca Mountain, Nevada. 6 refs., 5 figs., 2 tabs.

  5. Preliminary safety analysis of the Baita Bihor radioactive waste repository, Romania

    SciTech Connect

    Little, Richard; Bond, Alex; Watson, Sarah; Dragolici, Felicia; Matyasi, Ludovic; Matyasi, Sandor; Thorne, Mike

    2007-07-01

    A project funded under the European Commission's Phare Programme 2002 has undertaken an in-depth analysis of the operational and post-closure safety of the Baita Bihor repository. The repository has accepted low- and some intermediate-level radioactive waste from industry, medical establishments and research activities since 1985 and the current estimate is that disposals might continue for around another 20 to 35 years. The analysis of the operational and post-closure safety of the Baita Bihor repository was carried out in two iterations, with the second iteration resulting in reduced uncertainties, largely as a result taking into account new information on the hydrology and hydrogeology of the area, collected as part of the project. Impacts were evaluated for the maximum potential inventory that might be available for disposal to Baita Bihor for a number of operational and postclosure scenarios and associated conceptual models. The results showed that calculated impacts were below the relevant regulatory criteria. In light of the assessment, a number of recommendations relating to repository operation, optimisation of repository engineering and waste disposals, and environmental monitoring were made. (authors)

  6. Landscape modeling for dose calculations in the safety assessment of a repository for spent nuclear fuel

    SciTech Connect

    Lindborg, Tobias; Kautsky, Ulrik; Brydsten, Lars

    2007-07-01

    The Swedish Nuclear Fuel and Waste Management Co.,(SKB), pursues site investigations for the final repository for spent nuclear fuel at two sites in the south eastern part of Sweden, the Forsmark- and the Laxemar site. Data from the two site investigations are used to build site descriptive models of the areas. These models describe the bedrock and surface system properties important for designing the repository, the environmental impact assessment, and the long-term safety, i.e. up to 100,000 years, in a safety assessment. In this paper we discuss the methodology, and the interim results for, the landscape model, used in the safety assessment to populate the Forsmark site in the numerical dose models. The landscape model is built upon ecosystem types, e.g. a lake or a mire, (Biosphere Objects) that are connected in the landscape via surface hydrology. Each of the objects have a unique set of properties derived from the site description. The objects are identified by flow transport modeling, giving discharge points at the surface for all possible flow paths from the hypothetical repository in the bedrock. The landscape development is followed through time by using long-term processes e.g. shoreline displacement and sedimentation. The final landscape model consists of a number of maps for each chosen time period and a table of properties that describe the individual objects which constitutes the landscape. The results show a landscape that change over time during 20,000 years. The time period used in the model equals the present interglacial and can be used as an analogue for a future interglacial. Historically, the model area was covered by sea, and then gradually changes into a coastal area and, in the future, into a terrestrial inland landscape. Different ecosystem types are present during the landscape development, e.g. sea, lakes, agricultural areas, forest and wetlands (mire). The biosphere objects may switch from one ecosystem type to another during the

  7. The Geopolitics of Nuclear Waste.

    ERIC Educational Resources Information Center

    Marshall, Eliot

    1991-01-01

    The controversy surrounding the potential storage of nuclear waste at Yucca Mountain, Nevada, is discussed. Arguments about the stability of the site and the groundwater situation are summarized. The role of the U.S. Department of Energy and other political considerations are described. (CW)

  8. United States Program on Spent Nuclear Fuel and High-Level Radioactive Waste Management

    SciTech Connect

    Stewart, L.

    2004-10-03

    The President signed the Congressional Joint Resolution on July 23, 2002, that designated the Yucca Mountain site for a proposed geologic repository to dispose of the nation's spent nuclear fuel (SNF) and high-level radioactive waste (HLW). The United States (U.S.) Department of Energy's (DOE) Office of Civilian Radioactive Waste Management (OCRWM) is currently focusing its efforts on submitting a license application to the U.S. Nuclear Regulatory Commission (NRC) in December 2004 for construction of the proposed repository. The legislative framework underpinning the U.S. repository program is the basis for its continuity and success. The repository development program has significantly benefited from international collaborations with other nations in the Americas.

  9. Geochemical modelling of bentonite porewater in high-level waste repositories

    NASA Astrophysics Data System (ADS)

    Wersin, Paul

    2003-03-01

    The description of the geochemical properties of the bentonite backfill that serves as engineered barrier for nuclear repositories is a central issue for perfomance assessment since these play a large role in determining the fate of contaminants released from the waste. In this study the porewater chemistry of bentonite was assessed with a thermodynamic modelling approach that includes ion exchange, surface complexation and mineral equilibrium reactions. The focus was to identify the geochemical reactions controlling the major ion chemistry and acid-base properties and to explore parameter uncertainties specifically at high compaction degrees. First, the adequacy of the approach was tested with two distinct surface complexation models by describing recent experimental data performed at highly varying solid/liquid ratios and ionic strengths. The results indicate adequate prediction of the entire experimental data set. Second, the modelling was extended to repository conditions, taking as an example the current Swiss concept for high-level waste where the compacted bentonite backfill is surrounded by argillaceous rock. The main reactions controlling major ion chemistry were found to be calcite equilibrium and concurrent Na-Ca exchange reactions and de-protonation of functional surface groups. Third, a sensitivity analysis of the main model parameters was performed. The results thereof indicate a remarkable robustness of the model with regard to parameter uncertainties. The bentonite system is characterised by a large acid-base buffering capacity which leads to stable pH-conditions. The uncertainty in pH was found to be mainly induced by the pCO 2 of the surrounding host rock. The results of a simple diffusion-reaction model indicate only minor changes of porewater composition with time, which is primarily due to the geochemical similarities of the bentonite and the argillaceous host rock. Overall, the results show the usefulness of simple thermodynamic models to

  10. Public acceptance for centralized storage and repositories of low-level waste session (Panel)

    SciTech Connect

    Lutz, H.R.

    1995-12-31

    Participants from various parts of the world will provide a summary of their particular country`s approach to low-level waste management and the cost of public acceptance for low-level waste management facilities. Participants will discuss the number, geographic location, and type of low-level waste repositories and centralized storage facilities located in their countries. Each will discuss the amount, distribution, and duration of funds to gain public acceptance of these facilities. Participants will provide an estimated $/meter for centralized storage facilities and repositories. The panel will include a brief discussion about the ethical aspects of public acceptance costs, approaches for negotiating acceptance, and lessons learned in each country. The audience is invited to participate in the discussion.

  11. Regulatory Considerations Of Waste Emplacement Within The WIPP Repository: Random Versus Non-Random Distribution

    SciTech Connect

    Casey, S. C.; Patterson, R. L.; Gross, M.; Lickliter, K.; Stein, J. S.

    2003-02-25

    The U.S. Department of Energy (DOE) is responsible for disposing of transuranic waste in the Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico. As part of that responsibility, DOE must comply with the U.S. Environmental Protection Agency's (EPA) radiation protection standards in Title 40 Code of Federal Regulations (CFR), Parts 191 and 194. This paper addresses compliance with the criteria of 40 CFR Section 194.24(d) and 194.24(f) that require DOE to either provide a waste loading scheme for the WIPP repository or to assume random emplacement in the mandated performance and compliance assessments. The DOE established a position on waste loading schemes during the process of obtaining the EPA's initial Certification in 1998. The justification for utilizing a random waste emplacement distribution within the WIPP repository was provided to the EPA. During the EPA rulemaking process for the initial certification, the EPA questioned DOE on whether waste would be loaded randomly as modeled in long-term performance assessment (PA) and the impact, if any, of nonrandom loading. In response, DOE conducted an impact assessment for non-random waste loading. The results of this assessment supported the contention that it does not matter whether random or non-random waste loading is assumed for the PA. The EPA determined that a waste loading plan was unnecessary because DOE had assumed random waste loading and evaluated the potential consequences of non-random loading for a very high activity waste stream. In other words, the EPA determined that DOE was not required to provide a waste loading scheme because compliance is not affected by the actual distribution of waste containers in the WIPP.

  12. Microbial Effects on Nuclear Waste Packaging Materials

    SciTech Connect

    Horn, J; Martin, S; Carrillo, C; Lian, T

    2005-07-22

    Microorganisms may enhance corrosion of components of planned engineered barriers within the proposed nuclear waste repository at Yucca Mountain (YM). Corrosion could occur either directly, through processes collectively known as Microbiologically Influenced Corrosion (MIC), or indirectly, by adversely affecting the composition of water or brines that come into direct contact with engineered barrier surfaces. Microorganisms of potential concern (bacteria, archea, and fungi) include both those indigenous to Yucca Mountain and those that infiltrate during repository construction and after waste emplacement. Specific aims of the experimental program to evaluate the potential of microorganisms to affect damage to engineered barrier materials include the following: Indirect Effects--(1) Determine the limiting factors to microbial growth and activity presently in the YM environment. (2) Assess these limiting factors to aid in determining the conditions and time during repository evolution when MIC might become operant. (3) Evaluate present bacterial densities, the composition of the YM microbial community, and determining bacterial densities if limiting factors are overcome. During a major portion of the regulatory period, environmental conditions that are presently extant become reestablished. Therefore, these studies ascertain whether biomass is sufficient to cause MIC during this period and provide a baseline for determining the types of bacterial activities that may be expected. (4) Assess biogenic environmental effects, including pH, alterations to nitrate concentration in groundwater, the generation of organic acids, and metal dissolution. These factors have been shown to be those most relevant to corrosion of engineered barriers. Direct Effects--(1) Characterize and quantify microbiological effects on candidate containment materials. These studies were carried out in a number of different approaches, using whole YM microbiological communities, a subset of YM

  13. Intergenerational issues regarding nuclear power, nuclear waste, and nuclear weapons.

    PubMed

    Ahearne, J F

    2000-12-01

    Nuclear power, nuclear waste, and nuclear weapons raise substantial public concern in many countries. While new support for nuclear power can be found in arguments concerning greenhouse gases and global warming, the long-term existence of radioactive waste has led to requirements for 10,000-year isolation. Some of the support for such requirements is based on intergenerational equity arguments. This, however, places a very high value on lives far in the future. An alternative is to use discounting, as is applied to other resource applications. Nuclear weapons, even though being dismantled by the major nations, are growing in number due to the increase in the number of countries possessing these weapons of mass destruction. This is an unfortunate legacy for future generations. PMID:11314726

  14. Systematic management of environmental monitoring data for radioactive waste repository

    NASA Astrophysics Data System (ADS)

    Rhee, C. G.; Park, S. M.; Lim, Y. S.; Lee, H. J.; Park, J. W.; Kim, C. L.

    2003-04-01

    For the safe management of radwaste repository, data of the site and environment have to be collected and managed systematically. Particularly, for the radwaste repository, which has to be institutionally controlled for a long period after closure, data will be collected and maintained through the monitoring programme. To meet this requirement, a new programme called ``Site Information and Total Environmental data management System (SITES)" is being developed. The scope and function of the SITES programme are issued from the first stage of the SITES development. The hardware composed of a server and clients is constructed within those extents. The software system is developed with database and the three-tier server/client system consisted of a server, the middle-ware and PC client. The server is for the DB/GIS managements, and the PC client offers variable GUI in respect of end-user. A middle-ware is for the system management such as transaction. For this system, ArcSDE(ESRI) is used for unifying the spatial/attribute data to the Relative Database Management System. In the server/client system, the function of spatial illustration and analysis is embodied through ArcGIS. The SITES programme is designed with two modules of the Database Management System and the Monitoring and Assessment. The DBMS module is composed of two sub-modules. One is the Site Information Management System, which manages data on site characterization such as topography, geology, hydrogeology, engineering geology, etc. The other is the ENVironmental Information management System, which manages environmental data required for environmental assessment study. To enhance the effectiveness of SIMS and ENVIS, the objects are itemized through analyzing the end-user's demands reflected from domestic regulatory guidelines. The database is constructed based on Entity Relationship Diagram produced from each item. Also using ArcGIS with the spatial characteristics of the data, it enables groundwater and

  15. Framework for evaluating the utility of incentive systems for radioactive waste repository siting

    NASA Astrophysics Data System (ADS)

    Carnes, S. A.; Soderstrom, J.; Sorensen, J.; Peelle, E.; Reed, J. H.; Bjornstad, D. J.; Copenhaver, E. D.

    The importance of social and institutional issues in siting radioactive waste repositories has been recognized in recent years. Within this set of issues, the siting of repositories over the objections of members of potential host communities is viewed as especially problematic. Incentives to potential host communities have been suggested as a means of increasing local support for and offsetting local opposition to such facilities. Incentives are classified according to their function as mitigation, compensation or reward. Analysis of results of a 1980 survey (conducted by John Kelly, Complex Systems Group, University of New Hampshire) of 420 rural Wisconsin residents indicates that incentives may achieve the purpose of increasing support for and decreasing opposition to accepting a repository. Criteria for evaluating the utility of incentives are identified. It is suggested that meaningful evaluations of incentives can only be performed by members of potential host communities.

  16. Workshop on development of radionuclide getters for the Yucca Mountain waste repository: proceedings.

    SciTech Connect

    Moore, Robert Charles; Lukens, Wayne W. (Lawrence Berkeley National Laboratory)

    2006-03-01

    The proposed Yucca Mountain repository, located in southern Nevada, is to be the first facility for permanent disposal of spent reactor fuel and high-level radioactive waste in the United States. Total Systems Performance Assessment (TSPA) analysis has indicated that among the major radionuclides contributing to dose are technetium, iodine, and neptunium, all of which are highly mobile in the environment. Containment of these radionuclides within the repository is a priority for the Yucca Mountain Project (YMP). These proceedings review current research and technology efforts for sequestration of the radionuclides with a focus on technetium, iodine, and neptunium. This workshop also covered issues concerning the Yucca Mountain environment and getter characteristics required for potential placement into the repository.

  17. Can Shale Safely Host U.S. Nuclear Waste?

    NASA Astrophysics Data System (ADS)

    Neuzil, C. E.

    2013-07-01

    Even as cleanup efforts after Japan's Fukushima disaster offer a stark reminder of the spent nuclear fuel (SNF) stored at nuclear plants worldwide, the decision in 2009 to scrap Yucca Mountain as a permanent disposal site has dimmed hope for a repository for SNF and other high-level nuclear waste (HLW) in the United States anytime soon. About 70,000 metric tons of SNF are now in pool or dry cask storage at 75 sites across the United States [Government Accountability Office, 2012], and uncertainty about its fate is hobbling future development of nuclear power, increasing costs for utilities, and creating a liability for American taxpayers [Blue Ribbon Commission on America's Nuclear Future, 2012].

  18. 255 Agreements, not 293 Unresolved Issues, on the Proposed High-Level Waste Repository at Yucca Mountain, Nevada.

    NASA Astrophysics Data System (ADS)

    Leslie, B. W.

    2002-05-01

    The U.S. Nuclear Regulatory Commission (NRC) is an independent regulatory agency whose mission is to ensure that public health, safety, and the environment are protected when nuclear materials are used. The Nuclear Waste Policy Act (NWPA) authorized NRC to develop licensing criteria for disposal of spent nuclear fuel and high-level radioactive waste in the proposed geologic repository at Yucca Mountain, Nevada. NRC is also required by the NWPA to interact with the U.S. Department of Energy (DOE), the potential license applicant, prior to the submission of a potential license application. Finally, the NWPA requires NRC to provide preliminary comments on "...the extent to which the at-depth site characterization analysis and waste form proposal for such site seem to be sufficient for inclusion in any application by the Secretary for licensing of such site as a repository" to DOE for inclusion in any DOE site recommendation. In November 2001 NRC published the final licensing criteria and provided the Secretary of Energy with the NRC's preliminary comments regarding a possible geologic repository at Yucca Mountain. NRC's comments were subsequently included in a site recommendation made by the Secretary of Energy, and approved by the President, in February 2002. NRC's preliminary comments reflect many years of extensive pre-licensing interaction among the NRC staff, DOE, and various stakeholders. NRC staff engaged DOE in an issue resolution process on key technical issues and identified additional information that DOE would need to provide in any license application. As part of the issue resolution process NRC also obtained DOE's agreement to provide acceptable responses to the requests for information by the time of any license application. The issue resolution agreements, which totaled 293, have been characterized as being unresolved issues. However, NRC's preliminary comments (these and NRC's issue resolution agreements with DOE are available at our website, noted

  19. Khazar Iodine Production Plant Site Remediation in Turkmenistan. NORM Contaminated Waste Repository Establishment - 12398

    SciTech Connect

    Gelbutovskiy, Alexander B.; Cheremisin, Peter I.; Troshev, Alexander V.; Egorov, Alexander J.; Boriskin, Mikhail M.; Bogod, Mikhail A.

    2012-07-01

    Radiation safety provisions for NORM contaminated areas are in use in a number of the former Soviet republics. Some of these areas were formed by absorbed radionuclides at the iodine and bromine extraction sites. As a rule, there are not any plant radiation monitoring systems nor appropriate services to ensure personnel, population and environmental radiation safety. The most hazardous sites are those which are situated in the Caspian Sea coastal zone. The bulk of the accumulated waste is represented by a loose mixture of sand and charcoal, which was basically used as the iodine extraction sorbent. The amounts of these wastes were estimated to be approximately 20,000 metric tons. The waste contamination is mainly composed of Ra-226 (U-238 decay series) and Ra-224, Ra-228 (Th-232 decay series). In 2009, the 'ECOMET-S', a Closed Joint-Stock Company from St. Petersburg, Russian Federation, was authorized by the Turkmenistan government to launch the rehabilitation project. The project includes D and D activities, contaminated areas remediation, collected wastes safe transportation to the repository and its disposal following repository closure. The work at the Khazar chemical plant started in September, 2010. Comprehensive radiological surveys to estimate the waste quantities were carried out in advance. In course of the rehabilitation work at the site of the Khazar chemical plant additional waste quantities (5,000 MT, 10,000 m{sup 3}) were discovered after the sludge was dumped and drained. Disposal volumes for this waste was not provided initially. The additional volume of the construction wastes was required in order to accommodate all the waste to be disposed. For the larger disposal volume the project design enterprise VNIPIET, offered to erect a second wall outside the existing one and this solution was adopted. As of May, 2011, 40,575 m{sup 3} of contaminated waste were collected and disposed safely. This volume represents 96.6% of the initial repository volume

  20. Nuclear waste: A cancer cure?

    SciTech Connect

    1995-07-01

    In a marriage of strange bedfellows, scientists at one of the country`s most contaminated nuclear waste sites are collaborating with medical researchers to turn nuclear waste into an experimental therapy for cancer. Patients with Hodgkin`s disease and brain, ovarian, and breast cancers may be able to receive the new radiatio-based treatments in the next five to ten years. Recently, scientists at the Hanford site found a way to chemically extract a pure form of the radioisotope yttrium-90 from strontium-90, a by-product of plutonium production. Yttrium-90 is being tested in clinical trials at medical centers around the country as a treatment for various types of cancers, and the initial results are encouraging. The advantage of yttrium-90 over other radioisotopes is its short half-life.

  1. Salton Sea Geothermal Field, California, as a near-field natural analog of a radioactive waste repository in salt

    SciTech Connect

    Elders, W.A.; Cohen, L.H.

    1983-11-01

    Since high concentrations of radionuclides and high temperatures are not normally encountered in salt domes or beds, finding an exact geologic analog of expected near-field conditions in a mined nuclear waste repository in salt will be difficult. The Salton Sea Geothermal Field, however, provides an opportunity to investigate the migration and retardation of naturally occurring U, Th, Ra, Cs, Sr and other elements in hot brines which have been moving through clay-rich sedimentary rocks for up to 100,000 years. The more than thirty deep wells drilled in this field to produce steam for electrical generation penetrate sedimentary rocks containing concentrated brines where temperatures reach 365/sup 0/C at only 2 km depth. The brines are primarily Na, K, Ca chlorides with up to 25% of total dissolved solids; they also contain high concentrations of metals such as Fe, Mn, Li, Zn, and Pb. This report describes the geology, geophysics and geochemistry of this system as a prelude to a study of the mobility of naturally occurring radionuclides and radionuclide analogs within it. The aim of this study is to provide data to assist in validating quantitative models of repository behavior and to use in designing and evaluating waste packages and engineered barriers. 128 references, 33 figures, 13 tables.

  2. Efficacy of backfilling and other engineered barriers in a radioactive waste repository in salt

    SciTech Connect

    Claiborne, H.C.

    1982-09-01

    In the United States, investigation of potential host geologic formations was expanded in 1975 to include hard rocks. Potential groundwater intrusion is leading to very conservative and expensive waste package designs. Recent studies have concluded that incentives for engineered barriers and 1000-year canisters probably do not exist for reasonable breach scenarios. The assumption that multibarriers will significantly increase the safety margin is also questioned. Use of a bentonite backfill for surrounding a canister of exotic materials was developed in Sweden and is being considered in the US. The expectation that bentonite will remain essentially unchanged for hundreds of years for US repository designs may be unrealistic. In addition, thick bentonite backfills will increase the canister surface temperature and add much more water around the canister. The use of desiccant materials, such as CaO or MgO, for backfilling seems to be a better method of protecting the canister. An argument can also be made for not using backfill material in salt repositories since the 30-cm-thick space will provide for hole closure for many years and will promote heat transfer via natural convection. It is concluded that expensive safety systems are being considered for repository designs that do not necessarily increase the safety margin. It is recommended that the safety systems for waste repositories in different geologic media be addressed individually and that cost-benefit analyses be performed.

  3. Preliminary model of repository chemistry for the Waste Isolation Pilot Plant

    SciTech Connect

    Brush, L.H. ); Gbric-Galic, D. . Dept. of Civil Engineering); Reed, D.T. ); Tong, X. and Associates, Palo Alto, CA ); Vreeland, R.H. . Dept. of Biology); Westerman, R.E. )

    1990-01-01

    The design-basis, defense-related, transuranic (TRU) waste to be emplaced in the Waste Isolation Pilot Plant (WIPP) could, if sufficient H{sub 2}O and nutrients were present, produce as much as 1,500 moles of gas per drum of waste. Gas production could pressurize the repository to 150 atm (lithostatic pressure) and perhaps higher. Anoxic corrosion of Fe and Fe-base alloys and microbial degradation of cellulosics are the processes of greatest concern, but radiolysis of brine could also be important. The proposed backfill additives CaCO{sub 3}, CaO, CuSO{sub 4}, KOH, and NaOH may remove or prevent the production of some of the expected gases. Because of the heterogeneous nature of design-basis waste, the Eh and pH of any brine present in WIPP disposal rooms could vary significantly over short distances after reacting with the waste. The WIPP Project is investigating the consequences of gas production and considering engineered alternatives, including reprocessing the waste, to reduce gas production rates or potentials. Reprocessing would also reduce the range of Eh and pH expected for the repository. 12 refs.

  4. Transferring knowledge about high-level waste repositories: An ethical consideration

    SciTech Connect

    Berndes, S.; Kornwachs, K.

    1996-12-01

    The purpose of this paper is to present requirements to Information and Documentation Systems for high-level waste repositories from an ethical point of view. A structured synopsis of ethical arguments used by experts from Europe and America is presented. On the one hand the review suggests to reinforce the obligation to transfer knowledge about high level waste repositories. This obligation is reduced on the other hand by the objection that ethical obligations are dependent on the difference between our and future civilizations. This reflection results in proposing a list of well-balanced ethical arguments. Then a method is presented which shows how scenarios of possible future civilizations for different time horizons and related ethical arguments are used to justify requirements to the Information and Documentation System.

  5. Finite Element Stress Analysis of Spent Nuclear Fuel Disposal Canister in a Deep Geological Repository

    NASA Astrophysics Data System (ADS)

    Kwon, Young Joo; Choi, Jong Won

    This paper presents the finite element stress analysis of a spent nuclear fuel disposal canister to provide basic information for dimensioning the canister and configuration of canister components and consequently to suggest the structural analysis methodology for the disposal canister in a deep geological repository which is nowadays very important in the environmental waste treatment technology. Because of big differences in the pressurized water reactor (PWR) and the Canadian deuterium and uranium reactor (CANDU) fuel properties, two types of canisters are conceived. For manufacturing, operational reasons and standardization, however, both canisters have the same outer diameter and length. The construction type of canisters introduced here is a solid structure with a cast insert and a corrosion resistant overpack. The structural stress analysis is carried out using a finite element analysis code, NISA, and focused on the structural strength of the canister against the expected external pressures due to the swelling of the bentonite buffer and the hydrostatic head. The canister must withstand these large pressure loads. Consequently, canisters presented here contain 4 PWR fuel assemblies and 33×9 CANDU fuel bundles. The outside diameter of the canister for both fuels is 122cm and the cast insert diameter is 112cm. The total length of the canister is 483cm with the lid/bottom and the outer shell of 5cm.

  6. The petrographic criteria of selection of geological environments for building high-level waste (HLW) repository

    SciTech Connect

    Omelyanenko, B.I.; Petrov, V.A.; Yudintsev, S.V.; Zaraisky, G.P.; Starostin, V.I.

    1993-12-31

    Igneous rocks of basic composition (basalts, diabases, gabbro-dolerites, dunites, etc.) are an appropriate geological environment for high-level waste disposal. During interaction with hot ground waters their isolation ability will increase due to the decrease of hydraulic permeability and increase of their sorption ability. According to petrophysical characteristics, such rocks are viscous-rigid media with the highest mechanical stability and do not undergo any changes in properties over the whole temperature range, which is possible in a HLW repository.

  7. Plasma filtering techniques for nuclear waste remediation.

    PubMed

    Gueroult, Renaud; Hobbs, David T; Fisch, Nathaniel J

    2015-10-30

    Nuclear waste cleanup is challenged by the handling of feed stocks that are both unknown and complex. Plasma filtering, operating on dissociated elements, offers advantages over chemical methods in processing such wastes. The costs incurred by plasma mass filtering for nuclear waste pretreatment, before ultimate disposal, are similar to those for chemical pretreatment. However, significant savings might be achieved in minimizing the waste mass. This advantage may be realized over a large range of chemical waste compositions, thereby addressing the heterogeneity of legacy nuclear waste.

  8. Plasma filtering techniques for nuclear waste remediation

    DOE PAGESBeta

    Gueroult, Renaud; Hobbs, David T.; Fisch, Nathaniel J.

    2015-04-24

    Nuclear waste cleanup is challenged by the handling of feed stocks that are both unknown and complex. Plasma filtering, operating on dissociated elements, offers advantages over chemical methods in processing such wastes. The costs incurred by plasma mass filtering for nuclear waste pretreatment, before ultimate disposal, are similar to those for chemical pretreatment. However, significant savings might be achieved in minimizing the waste mass. As a result, this advantage may be realized over a large range of chemical waste compositions, thereby addressing the heterogeneity of legacy nuclear waste.

  9. Plasma filtering techniques for nuclear waste remediation.

    PubMed

    Gueroult, Renaud; Hobbs, David T; Fisch, Nathaniel J

    2015-10-30

    Nuclear waste cleanup is challenged by the handling of feed stocks that are both unknown and complex. Plasma filtering, operating on dissociated elements, offers advantages over chemical methods in processing such wastes. The costs incurred by plasma mass filtering for nuclear waste pretreatment, before ultimate disposal, are similar to those for chemical pretreatment. However, significant savings might be achieved in minimizing the waste mass. This advantage may be realized over a large range of chemical waste compositions, thereby addressing the heterogeneity of legacy nuclear waste. PMID:25956646

  10. Mechanisms governing the direct removal of wastes from the Waste Isolation Pilot Plant repository caused by exploratory drilling

    SciTech Connect

    Berglund, J.W.

    1992-12-01

    Two processes are identified that can influence the quantity of wastes brought to the ground surface when a waste disposal room of the Waste Isolation Pilot Plant is inadvertently penetrated by an exploratory borehole. The first mechanism is due to the erosion of the borehole wall adjacent to the waste caused by the flowing drilling fluid (mud); a quantitative computational model based upon the flow characteristics of the drilling fluid (laminar or turbulent) and other drilling parameters is developed and example results shown. The second mechanism concerns the motion of the waste and borehole spall caused by the flow of waste-generated gas to the borehole. Some of the available literature concerning this process is discussed, and a number of elastic and elastic-plastic finite-difference and finite-element calculations are described that confirm the potential importance of this process in directly removing wastes from the repository to the ground surface. Based upon the amount of analysis performed to date, it is concluded that it is not unreasonable to expect that volumes of waste several times greater than that resulting from direct cutting of a gauge borehole could eventually reach the ground surface. No definitive quantitative model for waste removal as a result of the second mechanism is presented; it is concluded that decomposed waste constitutive data must be developed and additional experiments performed to assess further the full significance of this latter mechanism.

  11. Expected near-field thermal environments in a sequentially loaded spent-fuel or high-level waste repository in salt

    SciTech Connect

    Rickertsen, L.D.; Arbital, J.G.; Claiborne, H.C.

    1982-01-01

    This report describes the effect of realistic waste emplacement schedules on repository thermal environments. Virtually all estimates to date have been based on instantaneous loading of wastes having uniform properties throughout the repository. However, more realistic scenarios involving sequential emplacement of wastes reflect the gradual filling of the repository over its lifetime. These cases provide temperatures that can be less extreme than with the simple approximation. At isolated locations in the repository, the temperatures approach the instantaneous-loading limit. However, for most of the repository, temperature rises in the near-field are 10 to 40 years behind the conservative estimates depending on the waste type and the location in the repository. Results are presented for both spent-fuel and high-level reprocessing waste repositories in salt, for a regional repository concept, and for a single national repository concept. The national repository is filled sooner and therefore more closely approximates the instantaneously loaded repository. However, temperatures in the near-field are still 20/sup 0/C or more below the values in the simple model for 40 years after startup of repository emplacement operations. The results suggest that current repository design concepts based on the instantaneous-loading predictions are very conservative. Therefore, experiments to monitor temperatures in a test and evaluation facility, for example, will need to take into account the reduced temperatures in order to provide data used in predicting repository performance.

  12. Bubblers Speed Nuclear Waste Processing at SRS

    ScienceCinema

    None

    2016-07-12

    At the Department of Energy's Savannah River Site, American Recovery and Reinvestment Act funding has supported installation of bubbler technology and related enhancements in the Defense Waste Processing Facility (DWPF). The improvements will accelerate the processing of radioactive waste into a safe, stable form for storage and permit expedited closure of underground waste tanks holding 37 million gallons of liquid nuclear waste.

  13. Bubblers Speed Nuclear Waste Processing at SRS

    SciTech Connect

    2010-11-14

    At the Department of Energy's Savannah River Site, American Recovery and Reinvestment Act funding has supported installation of bubbler technology and related enhancements in the Defense Waste Processing Facility (DWPF). The improvements will accelerate the processing of radioactive waste into a safe, stable form for storage and permit expedited closure of underground waste tanks holding 37 million gallons of liquid nuclear waste.

  14. Characterization of Heat-treated Clay Minerals in the Context of Nuclear Waste Disposal

    NASA Astrophysics Data System (ADS)

    Matteo, E. N.; Wang, Y.; Kruichak, J. N.; Mills, M. M.

    2015-12-01

    Clay minerals are likely candidates to aid in nuclear waste isolation due to their low permeability, favorable swelling properties, and high cation sorption capacities. Establishing the thermal limit for clay minerals in a nuclear waste repository is a potentially important component of repository design, as flexibility of the heat load within the repository can have a major impact on the selection of repository design. For example, the thermal limit plays a critical role in the time that waste packages would need to cool before being transferred to the repository. Understanding the chemical and physical changes, if any, that occur in clay minerals at various temperatures above the current thermal limit (of 100 °C) can enable decision-makers with information critical to evaluating the potential trade-offs of increasing the thermal limit within the repository. Most critical is gaining understanding of how varying thermal conditions in the repository will impact radionuclide sorption and transport in clay materials either as engineered barriers or as disposal media. A variety of repository-relevant clay minerals (illite, mixed layer illite/smectite, and montmorillonite), were heated for a range of temperatures between 100-1000 °C. These samples were characterized to determine surface area, mineralogical alteration, and cation exchange capacity (CEC). Our results show that for conditions up to 500 °C, no significant change occurs, so long as the clay mineral remains mineralogically intact. At temperatures above 500 °C, transformation of the layered silicates into silica phases leads to alteration that impacts important clay characteristics. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's Nation Nuclear Security Administration under contract DE-AC04-94AL85000. SAND Number: SAND2015-6524 A

  15. Summary strategy for compliance with postclosure requirements for the waste package for the Salt Repository Project: Final report

    SciTech Connect

    Not Available

    1988-03-01

    This document presents a summary of the strategy of the Salt Repository Project (SRP) to show compliance with the requirements for the waste package after permanent closure of the repository at the site in Deaf Smith County, Texas. The postclosure requirements that govern the performance of the waste package are those in 10 CFR 60.113 for substantially complete containment of the waste and for gradual release of radionuclides after the containment period, and for the postclosure design requirements in 10 CFR 60.135. Also, the waste package plays a role in showing compliance with the total system release requirement in 40 CFR 191.13. 12 refs.

  16. The Storage, Transportation, and Disposal of Nuclear Waste

    NASA Astrophysics Data System (ADS)

    Younker, J. L.

    2002-12-01

    The U.S. Congress established a comprehensive federal policy to dispose of wastes from nuclear reactors and defense facilities, centered on deep geologic disposal of high-level radioactive waste. Site screening led to selection of three potential sites and in 1987, Congress directed the Secretary of Energy to characterize only one site: Yucca Mountain in Nevada. For more than 20 years, teams of scientists and engineers have been evaluating the potential suitability of the site. On the basis of their work, the U.S. Secretary of Energy, Spencer Abraham, concluded in February 2002 that a safe repository can be sited at Yucca Mountain. On July 23, 2002, President Bush signed Joint Resolution 87 approving the site at Yucca Mountain for development of a repository, which allows the U.S. Department of Energy (DOE) to prepare and submit a license application to the U.S. Nuclear Regulatory Commission (NRC). Concerns have been raised relative to the safe transportation of nuclear materials. The U.S. history of transportation of nuclear materials demonstrates that high-level nuclear materials can be safely transported. Since the 1960s, over 1.6 million miles have been traveled by more than 2,700 spent nuclear fuel shipments, and there has never been an accident severe enough to cause a release of radioactive materials. The DOE will use NRC-certified casks that must be able to withstand very stringent tests. The same design features that allow the casks to survive severe accidents also limit their vulnerability to sabotage. In addition, the NRC will approve all shipping routes and security plans. With regard to long-term safety, the Yucca Mountain disposal system has five key attributes. First, the arid climate and geology of Yucca Mountain combine to ensure that limited water will enter the emplacement tunnels. Second, the DOE has designed a waste package and drip shield that are expected to have very long lifetimes in the repository environment. Third, waste form

  17. Socioeconomic studies of high-level nuclear waste disposal.

    PubMed Central

    White, G F; Bronzini, M S; Colglazier, E W; Dohrenwend, B; Erikson, K; Hansen, R; Kneese, A V; Moore, R; Page, E B; Rappaport, R A

    1994-01-01

    The socioeconomic investigations of possible impacts of the proposed repository for high-level nuclear waste at Yucca Mountain, Nevada, have been unprecedented in several respects. They bear on the public decision that sooner or later will be made as to where and how to dispose permanently of the waste presently at military weapons installations and that continues to accumulate at nuclear power stations. No final decision has yet been made. There is no clear precedent from other countries. The organization of state and federal studies is unique. The state studies involve more disciplines than any previous efforts. They have been carried out in parallel to federal studies and have pioneered in defining some problems and appropriate research methods. A recent annotated bibliography provides interested scientists with a compact guide to the 178 published reports, as well as to relevant journal articles and related documents. PMID:7971963

  18. Uranium immobilization and nuclear waste

    SciTech Connect

    Duffy, C.J.; Ogard, A.E.

    1982-02-01

    Considerable information useful in nuclear waste storage can be gained by studying the conditions of uranium ore deposit formation. Further information can be gained by comparing the chemistry of uranium to nuclear fission products and other radionuclides of concern to nuclear waste disposal. Redox state appears to be the most important variable in controlling uranium solubility, especially at near neutral pH, which is characteristic of most ground water. This is probably also true of neptunium, plutonium, and technetium. Further, redox conditions that immobilize uranium should immobilize these elements. The mechanisms that have produced uranium ore bodies in the Earth's crust are somewhat less clear. At the temperatures of hydrothermal uranium deposits, equilibrium models are probably adequate, aqueous uranium (VI) being reduced and precipitated by interaction with ferrous-iron-bearing oxides and silicates. In lower temperature roll-type uranium deposits, overall equilibrium may not have been achieved. The involvement of sulfate-reducing bacteria in ore-body formation has been postulated, but is uncertain. Reduced sulfur species do, however, appear to be involved in much of the low temperature uranium precipitation. Assessment of the possibility of uranium transport in natural ground water is complicated because the system is generally not in overall equilibrium. For this reason, Eh measurements are of limited value. If a ground water is to be capable of reducing uranium, it must contain ions capable of reducing uranium both thermodynamically and kinetically. At present, the best candidates are reduced sulfur species.

  19. Thermodynamic data management system for nuclear waste disposal performance assessment

    SciTech Connect

    Phillips, S.L.; Hale, F.V.; Siegel, M.D.

    1988-04-01

    Thermodynamic property values for use in assessing the performance of a nuclear waste repository are described. More emphasis is on a computerized data base management system which facilitates use of the thermodynamic data in sensitivity analysis and other studies which critically assess the performance of disposal sites. Examples are given of critical evaluation procedures; comparison of apparent equilibrium constants calculated from the data base, with other work; and of correlations useful in estimating missing values of both free energy and enthalpy of formation for aqueous species. 49 refs., 11 figs., 6 tabs.

  20. Geochemistry of Salado Formation brines recovered from the Waste Isolation Pilot Plant (WIPP) repository

    SciTech Connect

    Abitz, R.; Myers, J.; Drez, P.; Deal, D.

    1990-01-01

    Intergranular brines recovered from the repository horizon of the Waste Isolation Pilot Plant (WIPP) have major- and trace-element compositions that reflect seawater evaporation and diagenetic processes. Brines obtained from repository drill holes are heterogenous with respect to composition, but their compositional fields are distinct from those obtained from fluid inclusions in WIPP halite. The heterogeneity of brine compositions within the drill-hole population indicates a lack of mixing and fluid homogenization within the salt at the repository level. Compositional differences between intergranular (drill hole) and intragranular (fluid inclusions) brines is attributed to isolation of the latter from diagenetic fluids that were produced from dehydration reactions involving gypsum and clay minerals. Modeling of brine-rock equilibria indicates that equilibration with evaporite minerals controls the concentrations of major elements in the brine. Drill-hole brines are in equilibrium with the observed repository minerals halite, anhydrite, magnesite, polyhalite and quartz. The equilibrium model supports the derivation of drill-hole brines from near-field fluid, rather than large-scale vertical migration of fluids from the overlying Rustler or underlying Castile Formations. 13 refs., 6 figs., 6 tabs.

  1. Design of a high-level waste repository system for the United States

    SciTech Connect

    Baeza, J.L.; Boerigter, S.T.; Broadbent, G.E.; Cabello, E.D.; Duran, V.B.; Hollaway, W.R.; Karlberg, R.P.; Siegel, M.J.; Simonson, S.A.

    1988-05-12

    This report presents a conceptual design for a High Level Waste disposal system for fuel discharged by US commercial power reactors, using the Yucca Mountain repository site recently designated by federal legislation. Principal features of the resulting conceptual design include use of unit trains for periodic removal of old spent fuel from at-reactor storage facilities, buffer storage at the repository site using dual purpose transportation/storage casks, repackaging of the spent fuel from the dual purpose transportation/storage casks directly into special-alloy disposal canisters as intact fuel assemblies, without rod consolidation, emplacement into a repository of modular design, use of excavation techniques that minimize disturbance, both mechanical and chemical, to the geologic environment, a unit rail mounted vehicle for both the transportation and emplacement of the canister from the surface facilities to the underground repository, and a cost-effectiveness computer model of Yucca Mountain and an independent cost evaluation by members of the design team. 31 refs., 58 figs., 15 tabs.

  2. Innovative Conditioning Procedures for the Generation of Radioactive Waste Products which are Stable for Intermediate Storage or Repository-Independent in Final Storage

    SciTech Connect

    Steinmetz, H.J.; Heimbach, H.; Odoj, R.; Pruesse, R.; Wartenberg, W.

    2006-07-01

    The German Federal Government aims at a future final storage site for all kinds of radioactive waste within 30 years. Existing and newly-produced radioactive waste therefore has to be stored in interim storage facilities over very long periods of time. At present, most German radioactive waste or waste packages are produced and qualified according to the acceptance criteria of the projected final repository KONRAD. [1] Nevertheless, conditioning strategies for crude radioactive waste have to take into account the open question of the future repository site as well as requirements for long-term interim storage. The Quality Control Group for Radioactive Waste (in German: Produktkontrollstelle fuer radioaktive Abfaelle - PKS) works as an independent expert organisation for the quality checking of radioactive waste packages as well as evaluating conditioning procedures for waste containers suitable for final storage on behalf of the Federal Office for Radiation Protection (in German: Bundesamt fuer Strahlenschutz - BfS). The Institute for Safety Research and Reactor Technology (in German: Institut fuer Sicherheitsforschung and Reaktortechnik - ISR) of the Research Centre Juelich investigates scientific/technical problems of nuclear disposal, especially in the field of waste treatment. In this context, ISR and PKS investigated and/or evaluated innovative procedures, by means of which radioactive waste flows may be minimized and rendered inert. QSA Global (formerly: AEA Technology QSA) conditions radioactive waste of German users from the fields of medicine, research and industry as well as from its own radioactive source production and operates an intermediate storage facility for radioactive waste containers. This poster deals with the characteristics and possible applications of new waste fixation media on the basis of organic and inorganic mineral polymers; with the approach of producing inherently safe waste forms for various geological formations. Plasma technology

  3. Deep Geologic Nuclear Waste Disposal - No New Taxes - 12469

    SciTech Connect

    Conca, James; Wright, Judith

    2012-07-01

    To some, the perceived inability of the United States to dispose of high-level nuclear waste justifies a moratorium on expansion of nuclear power in this country. Instead, it is more an example of how science yields to social pressure, even on a subject as technical as nuclear waste. Most of the problems, however, stem from confusion on the part of the public and their elected officials, not from a lack of scientific knowledge. We know where to put nuclear waste, how to put it there, how much it will cost, and how well it will work. And it's all about the geology. The President's Blue Ribbon Commission on America's Nuclear Future has drafted a number of recommendations addressing nuclear energy and waste issues (BRC 2011) and three recommendations, in particular, have set the stage for a new strategy to dispose of high-level nuclear waste and to manage spent nuclear fuel in the United States: 1) interim storage for spent nuclear fuel, 2) resumption of the site selection process for a second repository, and 3) a quasi-government entity to execute the program and take control of the Nuclear Waste Fund in order to do so. The first two recommendations allow removal and storage of spent fuel from reactor sites to be used in the future, and allows permanent disposal of actual waste, while the third controls cost and administration. The Nuclear Waste Policy Act of 1982 (NPWA 1982) provides the second repository different waste criteria, retrievability, and schedule, so massive salt returns as the candidate formation of choice. The cost (in 2007 dollars) of disposing of 83,000 metric tons of heavy metal (MTHM) high-level waste (HLW) is about $ 83 billion (b) in volcanic tuff, $ 29 b in massive salt, and $ 77 b in crystalline rock. Only in salt is the annual revenue stream from the Nuclear Waste Fund more than sufficient to accomplish this program without additional taxes or rate hikes. The cost is determined primarily by the suitability of the geologic formation, i.e., how

  4. Electrochemical determination of the corrosion behavior of candidate alloys proposed for containment of high level nuclear waste in tuff

    SciTech Connect

    Glass, R.S.; Overturf, G.E.; Garrison, R.E.; McCright, R.D.

    1984-06-18

    Long-term geological disposal of nuclear waste requires corrosion-resistant canister materials for encapsulation. Several austenitic stainless steels are under consideration for such purposes for the disposal of high-level waste at the candidate repository site located at Yucca Mountain, Nevada. With regard to corrosion considerations, a worst case scenario at this prospective repository location would result from the intrusion of vadose water. This preliminary study focuses on the electrochemical and corrosion behavior of the candidate canister materials under worst-case repository environments. Electrochemical parameters related to localized attack (e.g., pitting potentials) and the electrochemical corrosion rates have been examined. 15 references, 15 figures, 4 tables.

  5. Two Approaches to the Geologic Disposal of Long-Lived Nuclear Waste: Yucca Mountain, Nevada and the Waste Isolation Pilot Plant, Carlsbad, New Mexico

    SciTech Connect

    Levich, R. A.; Patterson, R. L.; Linden, R. M.

    2002-02-26

    A key component of the US energy program is to provide for the safe and permanent isolation of spent nuclear fuel and long-lived radioactive waste produced through programs related to national defense and the generation of electric power by nuclear utilities. To meet this challenge, the US Department of Energy (DOE) has developed a multi-faceted approach to the geologic disposal of long-lived nuclear wastes. Two sites are being developed or studied as current or potential deep geologic repositories for long lived radioactive wastes, the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico and Yucca Mountain, Nevada.

  6. Estimation of the limitations for surficial water addition above a potential high level radioactive waste repository at Yucca Mountain, Nevada; Yucca Mountain Site Characterization Project

    SciTech Connect

    Fewell, M.E.; Sobolik, S.R.; Gauthier, J.H.

    1992-01-01

    The Yucca Mountain Site Characterization Project is studying Yucca Mountain in southwestern Nevada as a potential site for a high-level nuclear waste repository. Site characterization includes surface-based and underground testing. Analyses have been performed to design site characterization activities with minimal impact on the ability of the site to isolate waste, and on tests performed as part of the characterization process. One activity of site characterization is the construction of an Exploratory Studies Facility, consisting of underground shafts, drifts, and ramps, and the accompanying surface pad facility and roads. The information in this report addresses the following topics: (1) a discussion of the potential effects of surface construction water on repository-performance, and on surface and underground experiments; (2) one-dimensional numerical calculations predicting the maximum allowable amount of water that may infiltrate the surface of the mountain without affecting repository performance; and (3) two-dimensional numerical calculations of the movement of that amount of surface water and how the water may affect repository performance and experiments. The results contained herein should be used with other site data and scientific/engineering judgement in determining controls on water usage at Yucca Mountain. This document contains information that has been used in preparing Appendix I of the Exploratory Studies Facility Design Requirements document for the Yucca Mountain Site Characterization Project.

  7. Degradation and failure susceptibility of carbon steels in simulated Yucca Mountain nuclear repository environments

    NASA Astrophysics Data System (ADS)

    Yilmaz, Ahmet

    Environmental degradation and cracking of medium carbon steel (MCS) rock bolts and low carbon steel (LCS) I-beam have been investigated by experimental methods such as linear polarization, impedance spectroscopy, weight loss measurements, and electro-mechanical dynamic slow strain rate tensile (SSRT) tests, along with potentiostatic in-situ potential-current monitoring techniques. The experiments were conducted in concentrated aqueous environments of various temperatures, which simulated the conditions at the Yucca Mountain (YM) nuclear waste repository site, where the candidate structural materials introduced above, will be used for supporting the waste repository tunnels. MCS corroded at medium general rates approximately around 40 mum/year to 200 mum/year in de-aerated simulated YM waters of various temperatures and concentrations. Increased temperatures increased the corrosion rates in the all de-aerated waters. Increased concentrations of overall species in the simulated waters also increased the corrosion rates, but only slightly. Impedance spectroscopy revealed similar trends for temperature and concentration effects on the rates in both aerated and deaerated environments. Aeration increased corrosion rates significantly in dilute (1X) and ten times concentrated (10X) waters at all temperatures. However, inhibitive precipitates on the specimens formed by oxygen-environment reactions at higher temperatures (up to 85°C) in hundred times concentrated (100X) waters decreased corrosion rates drastically, resulting some localized corrosion and pitting. The average rates were determined to be between approximately 100 mu/year and 1000 mu/year in the entire concentration and temperature range tested. Electrochemical results showed slightly higher rates compared to the other tests because of their much shorter testing period, therefore in general they should be taken as conservative upper bounds. SSRT on LCS under various imposed metal-electrolyte interface

  8. Nuclear waste storage: A legislative issue

    SciTech Connect

    Novak, S.G.

    1995-12-01

    Following an intense legislative battle, the Minnesota Legislature reaches consensus on a plan to authorize limited dry cask storage of nuclear waste at Northern States Power`s Prairie Island nuclear plant.

  9. Global Nuclear Energy Partnership Waste Treatment Baseline

    SciTech Connect

    Dirk Gombert; William Ebert; James Marra; Robert Jubin; John Vienna

    2008-05-01

    The Global Nuclear Energy Partnership program (GNEP) is designed to demonstrate a proliferation-resistant and sustainable integrated nuclear fuel cycle that can be commercialized and used internationally. Alternative stabilization concepts for byproducts and waste streams generated by fuel recycling processes were evaluated and a baseline of waste forms was recommended for the safe disposition of waste streams. Waste forms are recommended based on the demonstrated or expected commercial practicability and technical maturity of the processes needed to make the waste forms, and performance of the waste form materials when disposed. Significant issues remain in developing technologies to process some of the wastes into the recommended waste forms, and a detailed analysis of technology readiness and availability may lead to the choice of a different waste form than what is recommended herein. Evolving regulations could also affect the selection of waste forms.

  10. Experimental assessment of non-treated bentonite as the buffer material of a radioactive waste repository.

    PubMed

    Choi, J; Kang, C H; Whang, J

    2001-05-01

    The bentonite-based material being evaluated in several countries as potential barriers and seals for a nuclear waste disposal system is of mostly sodium type, whereas most bentonite available in Korea is known to be of calcium type. In order to investigate whether local Korean bentonite could be useful as a buffer or sealing material in an HLW repository system, raw bentonites sampled from the south-east area of Korea were examined in terms of their physicochemical properties such as surface area, CEC, swelling rate, and distribution coefficient. The diffusion behavior of some radionuclides of interest in compacted bentonite was also investigated. Considering that HLW generates decay heat over a long time, the thermal effect on the physicochemical properties of bentonite was also included. Four local samples were identified as Ca-bentonite through XRD and chemical analysis. Of the measured values of surface area, CEC and swelling rate of the local samples, Sample-A was found to have the greatest properties as the most likely candidate barrier material. The distribution coefficients of Cs-137, Sr-85, Co-60 and Am-241 for Sample-A sample were measured by the batch method. Sorption equilibrium was reached in around 8 to 10 days, but that of Sr was found to be reached earlier. Comparing the results of this study with the reference data, domestic bentonite was found to have a relatively high sorption ability. For the effect of varying concentration on sorption, the values of Kd peaked at 10(-9)-10(-7) mol/l of radionuclide concentration. In XRD analysis, the (001) peak of Sample-A was fully collapsed above 200 degrees C. The shoulder appearing at about 150 degrees C in the DSC curve was found to be evidence that Sample-A is predominated by Ca-montmorillonite. The loss of swelling capacity and CEC of Sample-A started at about 100 degrees C. The swelling data and the (001) peak intensity of the heat-treated sample showed that they were linearly interrelated. The measured

  11. Experimental assessment of non-treated bentonite as the buffer material of a radioactive waste repository.

    PubMed

    Choi, J; Kang, C H; Whang, J

    2001-05-01

    The bentonite-based material being evaluated in several countries as potential barriers and seals for a nuclear waste disposal system is of mostly sodium type, whereas most bentonite available in Korea is known to be of calcium type. In order to investigate whether local Korean bentonite could be useful as a buffer or sealing material in an HLW repository system, raw bentonites sampled from the south-east area of Korea were examined in terms of their physicochemical properties such as surface area, CEC, swelling rate, and distribution coefficient. The diffusion behavior of some radionuclides of interest in compacted bentonite was also investigated. Considering that HLW generates decay heat over a long time, the thermal effect on the physicochemical properties of bentonite was also included. Four local samples were identified as Ca-bentonite through XRD and chemical analysis. Of the measured values of surface area, CEC and swelling rate of the local samples, Sample-A was found to have the greatest properties as the most likely candidate barrier material. The distribution coefficients of Cs-137, Sr-85, Co-60 and Am-241 for Sample-A sample were measured by the batch method. Sorption equilibrium was reached in around 8 to 10 days, but that of Sr was found to be reached earlier. Comparing the results of this study with the reference data, domestic bentonite was found to have a relatively high sorption ability. For the effect of varying concentration on sorption, the values of Kd peaked at 10(-9)-10(-7) mol/l of radionuclide concentration. In XRD analysis, the (001) peak of Sample-A was fully collapsed above 200 degrees C. The shoulder appearing at about 150 degrees C in the DSC curve was found to be evidence that Sample-A is predominated by Ca-montmorillonite. The loss of swelling capacity and CEC of Sample-A started at about 100 degrees C. The swelling data and the (001) peak intensity of the heat-treated sample showed that they were linearly interrelated. The measured

  12. Stress corrosion cracking tests on high-level-waste container materials in simulated tuff repository environments

    SciTech Connect

    Abraham, T.; Jain, H.; Soo, P.

    1986-06-01

    Types 304L, 316L, and 321 austenitic stainless steel and Incoloy 825 are being considered as candidate container materials for emplacing high-level waste in a tuff repository. The stress corrosion cracking susceptibility of these materials under simulated tuff repository conditions was evaluated by using the notched C-ring method. The tests were conducted in boiling synthetic groundwater as well as in the steam/air phase above the boiling solutions. All specimens were in contact with crushed Topopah Spring tuff. The investigation showed that microcracks are frequently observed after testing as a result of stress corrosion cracking or intergranular attack. Results showing changes in water chemistry during test are also presented.

  13. Questioning nuclear waste substitution: a case study.

    PubMed

    Marshall, Alan

    2007-03-01

    This article looks at the ethical quandaries, and their social and political context, which emerge as a result of international nuclear waste substitution. In particular it addresses the dilemmas inherent within the proposed return of nuclear waste owned by Japanese nuclear companies and currently stored in the United Kingdom. The UK company responsible for this waste, British Nuclear Fuels Limited (BNFL), wish to substitute this high volume intermediate-level Japanese-owned radioactive waste for a much lower volume of much more highly radioactive waste. Special focus is given to ethical problems that they, and the UK government, have not wished to address as they move forward with waste substitution. The conclusion is that waste substitution can only be considered an ethical practice if a set of moderating conditions are observed by all parties. These conditions are listed and, as of yet, they are not being observed.

  14. An investigation of the impact of conceptual model uncertainty on the estimated performance of a hypothetical high-level nuclear waste repository site in unsaturated, fractured tuff; Yucca Mountain Site Characterization Project

    SciTech Connect

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

    1992-04-01

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

  15. Reducing the likelihood of future human activities that could affect geologic high-level waste repositories

    SciTech Connect

    Not Available

    1984-05-01

    The disposal of radioactive wastes in deep geologic formations provides a means of isolating the waste from people until the radioactivity has decayed to safe levels. However, isolating people from the wastes is a different problem, since we do not know what the future condition of society will be. The Human Interference Task Force was convened by the US Department of Energy to determine whether reasonable means exist (or could be developed) to reduce the likelihood of future human unintentionally intruding on radioactive waste isolation systems. The task force concluded that significant reductions in the likelihood of human interference could be achieved, for perhaps thousands of years into the future, if appropriate steps are taken to communicate the existence of the repository. Consequently, for two years the task force directed most of its study toward the area of long-term communication. Methods are discussed for achieving long-term communication by using permanent markers and widely disseminated records, with various steps taken to provide multiple levels of protection against loss, destruction, and major language/societal changes. Also developed is the concept of a universal symbol to denote Caution - Biohazardous Waste Buried Here. If used for the thousands of non-radioactive biohazardous waste sites in this country alone, a symbol could transcend generations and language changes, thereby vastly improving the likelihood of successful isolation of all buried biohazardous wastes.

  16. Attenuation of elastic waves in bentonite and monitoring of radioactive waste repositories

    NASA Astrophysics Data System (ADS)

    Biryukov, A.; Tisato, N.; Grasselli, G.

    2016-04-01

    Deep geological repositories, isolated from the geosphere by an engineered bentonite barrier, are currently considered the safest solution for high-level radioactive waste (HLRW) disposal. As the physical conditions and properties of the bentonite barrier are anticipated to change with time, seismic tomography was suggested as a viable technique to monitor the physical state and integrity of the barrier and to timely detect any unforeseen failure. To do so, the seismic monitoring system needs to be optimized, and this can be achieved by conducting numerical simulations of wave propagation in the repository geometry. Previous studies treated bentonite as an elastic medium, whereas recent experimental investigations indicate its pronounced viscoelastic behaviour. The aims of this contribution are (i) to numerically estimate the effective attenuation of bentonite as a function of temperature T and water content Wc, so that synthetic data can accurately reproduce experimental traces and (ii) assess the feasibility and limitation of the HLRW repository monitoring by simulating the propagation of sonic waves in a realistic repository geometry. A finite difference method was utilized to simulate the wave propagation in experimental and repository setups. First, the input of the viscoelastic model was varied to achieve a match between experimental and numerical traces. The routine was repeated for several values of Wc and T, so that quality factors Qp(Wc, T) and Qs(Wc, T) were obtained. Then, the full-scale monitoring procedure was simulated for six scenarios, representing the evolution of bentonite's physical state. The estimated Qp and Qs exhibited a minimum at Wc = 20 per cent and higher sensitivity to Wc, rather than T, suggesting that pronounced inelasticity of the clay has to be taken into account in geophysical modelling and analysis. The repository-model traces confirm that active seismic monitoring is, in principle, capable of depicting physical changes in the

  17. Chemical Environment at Waste Package Surfaces in a High-Level Radioactive Waste Repository

    SciTech Connect

    Carroll, S; Alai, M; Craig, L; Gdowski, G; Hailey, P; Nguyen, Q A; Rard, J; Staggs, K; Sutton, M; Wolery, T

    2005-05-26

    We have conducted a series of deliquescence, boiling point, chemical transformation, and evaporation experiments to determine the composition of waters likely to contact waste package surfaces over the thermal history of the repository as it heats up and cools back down to ambient conditions. In the above-boiling period, brines will be characterized by high nitrate to chloride ratios that are stable to higher temperatures than previously predicted. This is clearly shown for the NaCl-KNO{sub 3} salt system in the deliquescence and boiling point experiments in this report. Our results show that additional thermodynamic data are needed in nitrate systems to accurately predict brine stability and composition due to salt deliquescence in dust deposited on waste package surfaces. Current YMP models capture dry-out conditions but not composition for NaCl-KNO{sub 3} brines, and they fail to predict dry-out conditions for NaCl-KNO{sub 3}-NaNO{sub 3} brines. Boiling point and deliquescence experiments are needed in NaCl-KNO{sub 3}-NaNO{sub 3} and NaCl-KNO{sub 3}-NaNO{sub 3}-Ca(NO{sub 3}){sub 2} systems to directly determine dry-out conditions and composition, because these salt mixtures are also predicted to control brine composition in the above-boiling period. Corrosion experiments are needed in high temperature and high NO{sub 3}:Cl brines to determine if nitrate inhibits corrosion in these concentrated brines at temperatures above 160 C. Chemical transformations appear to be important for pure calcium- and magnesium-chloride brines at temperatures greater than 120 C. This stems from a lack of acid gas volatility in NaCl/KNO{sub 3} based brines and by slow CO{sub 2}(g) diffusion in alkaline brines. This suggests that YMP corrosion models based on bulk solution experiments over the appropriate composition, temperature, and relative humidity range can be used to predict corrosion in thin brine films formed by salt deliquescence. In contrast to the above-boiling period, the

  18. Modeling of radiation effects on nuclear waste package materials

    SciTech Connect

    Simonson, S.A.

    1988-09-01

    A methodology is developed for the assessment of radiation effects on nuclear waste package materials. An assessment of the current status of understanding with regard to waste package materials and their behavior in radiation environments is presented. The methodology is used to make prediction as to the chemically induced changes in the groundwater surrounding nuclear waste packages in a repository in tuff. The predictions indicate that mechanisms not currently being pursued by the Department of Energy may be a factor in the long-term performance of nuclear waste packages. The methodology embodies a physical model of the effects of radiation on aqueous solutions. Coupled to the physical model is a method for analyzing the complex nature of the physical model using adjoint sensitivity analysis. The sensitivity aid in both the physical understanding of the processes involved as well as aiding in eliminating portions of the model that have no bearing on the desired results. A computer implementation of the methodology is provided. 128 refs.

  19. Plasma filtering techniques for nuclear waste remediation

    SciTech Connect

    Gueroult, Renaud; Hobbs, David T.; Fisch, Nathaniel J.

    2015-04-24

    The economical viability of nuclear waste cleanup e orts could, in some cases, be put at risk due to the difficulties faced in handling unknown and complex feedstocks. Plasma filtering, which operates on dissociated elements, offers advantages over chemical techniques for the processing of such wastes. In this context, the economic feasibility of plasma mass filtering for nuclear waste pretreatment before ultimate disposal is analyzed. Results indicate similar costs for chemical and plasma solid-waste pretreatment per unit mass of waste, but suggest significant savings potential as a result of a superior waste mass minimization. This performance improvement is observed over a large range of waste chemical compositions, representative of legacy waste's heterogeneity. Although smaller, additional savings arise from the absence of a secondary liquid waste stream, as typically produced by chemical techniques.

  20. Plasma filtering techniques for nuclear waste remediation

    DOE PAGESBeta

    Gueroult, Renaud; Hobbs, David T.; Fisch, Nathaniel J.

    2015-04-24

    The economical viability of nuclear waste cleanup e orts could, in some cases, be put at risk due to the difficulties faced in handling unknown and complex feedstocks. Plasma filtering, which operates on dissociated elements, offers advantages over chemical techniques for the processing of such wastes. In this context, the economic feasibility of plasma mass filtering for nuclear waste pretreatment before ultimate disposal is analyzed. Results indicate similar costs for chemical and plasma solid-waste pretreatment per unit mass of waste, but suggest significant savings potential as a result of a superior waste mass minimization. This performance improvement is observed overmore » a large range of waste chemical compositions, representative of legacy waste's heterogeneity. Although smaller, additional savings arise from the absence of a secondary liquid waste stream, as typically produced by chemical techniques.« less

  1. Molecular glasses for nuclear waste encapsulation

    SciTech Connect

    Ropp, R.C.

    1982-09-28

    A molecular glass based upon a phosphate of aluminum, or other trivalent metal, provides significant improvement over prior art glasses for encapsulation of high level radioactive nuclear waste. When containing a controlled amount of those elemental oxides found in a typical nuclear waste, the waste-glass would not devitrify under conditions which produced devitrification in the non-nuclear-waste-containing glass, exhibited hydrolysis losses lower by an order of magnitude, had high solvency power for those elemental oxides, exhibited little tendency for internal crystallite formation, and possessed other desirable physical characteristics, all in direct antithesis to the properties of the best prior-known glasses used for this application.

  2. Concept for Underground Disposal of Nuclear Waste

    NASA Technical Reports Server (NTRS)

    Bowyer, J. M.

    1987-01-01

    Packaged waste placed in empty oil-shale mines. Concept for disposal of nuclear waste economically synergistic with earlier proposal concerning backfilling of oil-shale mines. New disposal concept superior to earlier schemes for disposal in hard-rock and salt mines because less uncertainty about ability of oil-shale mine to contain waste safely for millenium.

  3. Effects of transportation of spent nuclear fuel on repository SNF performance

    SciTech Connect

    Quinn, Robert

    2007-07-01

    Available in abstract form only. Full text of publication follows: Spent nuclear fuel (SNF) destined for emplacement in a repository must be transported to the repository. Most worldwide experience with SNF transportation has been with low burnup SNF, Further, since much of the transported SNF was destined for reprocessing, the integrity of the fuel upon arrival was only a minimal concern. For repository emplacement, the long term performance of many of the barriers is crucial to the analytical predictions of overall performance of the repository over the long time spans which must be considered. As a result, the condition of the SNF after transportation is very important. This evaluation looks at the issues associated with SNF performance in a repository, specifically issues associated with high burnup fuel and transportation effects on cladding conditions. The issues associated with high-burnup fuels include hydride formation and post-irradiation temperatures that can lead to hydrogen embrittlement and hydride reorientation which can affect cladding integrity performance. Issues associated with effects of post-irradiation discharge wet and dry storage of SNF and effects on transportation as they relate to the integrity of the SNF cladding materials include the effects of potential oxidation of the fuel, as well as effects of transportation conditions due to vibration. The evaluation also considers how such issues, and the ability to address them, may be affected by the US DOE canister-based repository design approach. Experience in licensing SNF for transportation will be cited in developing suggestions for addressing these issues, and possible future activities which may be needed to further to address these issues will be identified. (author)

  4. Managing the nation`s nuclear waste. Site descriptions: Cypress Creek, Davis Canyon, Deaf Smith, Hanford Reference, Lavender Canyon, Richton Dome, Swisher, Vacherie Dome, and Yucca Mountain

    SciTech Connect

    1985-12-31

    In 1982, the Congress enacted the Nuclear Waste Policy Act (Public Law 97-425), which established a comprehensive national program directed toward siting, constructing, and operating geologic repositories for the permanent disposal of high-level radioactive waste. In February 1983, the United States Department of Energy (DOE) identified the nine referenced repository locations as potentially acceptable sites for a mined geologic repository. These sites have been evaluated in accordance with the DOE`s General Guidelines for the Recommendation of Sites for Nuclear Waste Repositories. The DOE findings and determinations are based on the evaluations contained in the draft Environmental Assessments (EA). A final EA will be prepared after considering the comments received on the draft EA. The purpose of this document is to provide the public with specific site information on each potential repository location.

  5. Interaction Between Hyperalkaline Fluids and Rocks Hosting Repositories for Radioactive Waste: Reactive Transport Simulations

    SciTech Connect

    Soler, Josep M.; Maeder, Urs K.

    2005-09-15

    Reactive transport calculations simulating the interaction between hyperalkaline solutions derived from the degradation of cement and potential host rocks for repositories for low- and intermediate-level radioactive waste have been performed. Two different cases are shown: (a) The example of the planned repository at Wellenberg and (b) the modeling of the GTS-HPF experiment at the Grimsel Test Site. The GIMRT code has been used for the simulations. Mineral reactions are described by kinetic rate laws. The reaction rates for the primary minerals are based on experimentally determined rates published in the literature and geometric considerations combined with measurements regarding mineral surface areas. Relatively fast rates for the secondary minerals have been used, so the results resemble the local equilibrium solution for these minerals. In both cases, the alteration of the rock and the precipitation of secondary phases cause a reduction in the permeability of the system, which would actually be beneficial for the performance of a repository. Mineral surface area controls, to a large extent, the amount of mineral alteration and the change in permeability.

  6. Feasibility assessment of copper-base waste package container materials in a tuff repository

    SciTech Connect

    Acton, C.F.; McCright, R.D.

    1986-09-30

    This report discussed progress made during the second year of a two-year study on the feasibility of using copper or a copper-base alloy as a container material for a waste package in a potential repository in tuff rock at the Yucca Mountain site in Nevada. Corrosion testing in potentially corrosive irradiated environments received emphasis during the feasibility study. Results of experiments to evaluate the effect of a radiation field on the uniform corrosion rate of the copper-base materials in repository-relevant aqueous environments are given as well as results of an electrochemical study of the copper-base materials in normal and concentrated J-13 water. Results of tests on the irradiation of J-13 water and on the subsequent formation of hydrogen peroxide are given. A theoretical study was initiated to predict the long-term corrosion behavior of copper in the repository. Tests were conducted to determine whether copper would adversely affect release rates of radionuclides to the environment because of degradation of the Zircaloy cladding. A manufacturing survey to determine the feasibility of producing copper containers utilizing existing equipment and processes was completed. The cost and availability of copper was also evaluated and predicted to the year 2000. Results of this feasibility assessment are summarized.

  7. Conceptual waste package interim product specifications and data requirements for disposal of borosilicate glass defense high-level waste forms in salt geologic repositories

    SciTech Connect

    Not Available

    1983-06-01

    The conceptual waste package interim product specifications and data requirements presented are applicable specifically to the normal borosilicate glass product of the Defense Waste Processing Facility (DWPF). They provide preliminary numerical values for the defense high-level waste form parameters and properties identified in the waste form performance specification for geologic isolation in salt repositories. Subject areas treated include containment and isolation, operational period safety, criticality control, waste form/production canister identification, and waste package performance testing requirements. This document was generated for use in the development of conceptual waste package designs in salt. It will be revised as additional data, analyses, and regulatory requirements become available.

  8. Nevada nuclear waste storage investigations. Quarterly report, October-December 1981

    SciTech Connect

    1982-03-01

    The Nevada Nuclear Waste Storage Investigations (NNWSI) are investigating and determining whether specific underground rock masses are suitable for permanently disposing of highly radioactive wastes, studying and determining whether the Nevada Test Site (NTS) would qualify as a suitable repository site, and developing and demonstrating the capability to safely handle and store commercial spent reactor fuel and high-level waste. This document is a compilation of the technical progress of the principal project participants of the NNWSI in meeting the objectives described in the draft FY 1982 NNWSI Project Plan and revised planning documentation during the first quarter of FY 1982. The NNWSI Project Work Breakdown Structure (WBS) for FY 1982 is comprised of eight tasks which form the main sections of this document. They are: systems; waste package; site; repository; regulatory and institutional; test facilities; land acquisition; and program management. Scenarios for the release of radionuclide from a repository in alternate rock types occuring in the southwest NTS area were ranked by probabilities. Analysis of data from 60 wells in and around NTS are nearing completion. A computerized data recording and earthquake detection system that is more efficient was made operational. A series of 55 evaluations of repository locations in the screening area was performed. A review has been completed covering the likelihood of creep failure in a tuff repository. (DMC)

  9. Nuclear waste disposal educational forum

    SciTech Connect

    Not Available

    1982-10-18

    In keeping with a mandate from the US Congress to provide opportunities for consumer education and information and to seek consumer input on national issues, the Department of Energy's Office of Consumer Affairs held a three-hour educational forum on the proposed nuclear waste disposal legislation. Nearly one hundred representatives of consumer, public interest, civic and environmental organizations were invited to attend. Consumer affairs professionals of utility companies across the country were also invited to attend the forum. The following six papers were presented: historical perspectives; status of legislation (Senate); status of legislation (House of Representatives); impact on the legislation on electric utilities; impact of the legislation on consumers; implementing the legislation. All six papers have been abstracted and indexed for the Energy Data Base.

  10. Nuclear waste storage in Gabon

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    The geological record of Oklo, Republic of Gabon, may provide clues to the best and safest methods of storing radioactive waste products. A group of isotope geochemists from the Los Alamos National Laboratory has begun a field and laboratory study of natural geologic nuclear reactors in equatorial Africa to assess the distribution of radioactive products in the ground. The project requires a good deal of study, and the early results must be considered preliminary; nonetheless, they are very promising. T. Benjamin of Los Alamos reported recently at a meeting of the Geological Society of Washington that radionuclides did not appear to migrate great distances from several of the natural reactors at the Oklo deposit.

  11. Summary report of first and foreign high-level waste repository concepts; Technical report, working draft 001

    SciTech Connect

    Hanke, P.M.

    1987-11-04

    Reference repository concepts designs adopted by domestic and foreign waste disposal programs are reviewed. Designs fall into three basic categories: deep borehole from the surface; disposal in boreholes drilled from underground excavations; and disposal in horizontal tunnels or drifts. The repository concepts developed in Sweden, Switzerland, Finland, Canada, France, Japan, United Kingdom, Belgium, Italy, Holland, Denmark, West Germany and the United States are described. 140 refs., 315 figs., 19 tabs.

  12. Death Valley Lower Carbonate Aquifer Monitoring Program Wells Down Gradient of the Proposed Yucca Mountain Nuclear Waste Repository, U. S. Department of Energy Grant DE-RW0000233 2010 Project Report, prepared by The Hydrodynamics Group, LLC for Inyo County Yucca Mountain Repository Assessment Office

    SciTech Connect

    King, Michael J; Bredehoeft, John D., Dr.

    2010-09-03

    Inyo County completed the first year of the U.S. Department of Energy Grant Agreement No. DE-RW0000233. This report presents the results of research conducted within this Grant agreement in the context of Inyo County's Yucca Mountain oversight program goals and objectives. The Hydrodynamics Group, LLC prepared this report for Inyo County Yucca Mountain Repository Assessment Office. The overall goal of Inyo County's Yucca Mountain research program is the evaluation of far-field issues related to potential transport, by ground water, of radionuclide into Inyo County, including Death Valley, and the evaluation of a connection between the Lower Carbonate Aquifer (LCA) and the biosphere. Data collected within the Grant is included in interpretive illustrations and discussions of the results of our analysis. The centeral elements of this Grant prgoram was the drilling of exploratory wells, geophysical surveys, geological mapping of the Southern Funeral Mountain Range. The cullimination of this research was 1) a numerical ground water model of the Southern Funeral Mountain Range demonstrating the potential of a hydraulic connection between the LCA and the major springs in the Furnace Creek area of Death Valley, and 2) a numerical ground water model of the Amargosa Valley to evaluate the potential for radionuclide transport from Yucca Mountain to Inyo County, California. The report provides a description of research and activities performed by The Hydrodynamics Group, LLC on behalf of Inyo County, and copies of key work products in attachments to this report.

  13. Nuclear Waste Management. Semiannual progress report, October 1984-March 1985

    SciTech Connect

    McElroy, J.L.; Powell, J.A.

    1985-06-01

    Progress reports are presented for the following studies on radioactive waste management: defense waste technology; nuclear waste materials characterization center; and supporting studies. 19 figs., 29 tabs.

  14. Characteristics of potential repository wastes. Peer review report for revision 1 of DOE/RW-0184

    SciTech Connect

    Cowart, C.G.; Notz, K.J.

    1992-10-01

    This report presents the results of a fully documented peer review of DOE/RW-0184, Rev. 1, ``Characteristics of Potential Repository Wastes``. The peer review was chaired and administered by oak Ridge National Laboratory (ORNL) for the Department of Energy (DOE), Office of Civilian Radioactive Waste Management (OCRWM) and was conducted in accordance with OCRWM QA procedure QAAP 3.3 ``Peer Review`` for the purpose of quailing the document for use in OCRWM quality-affecting work. The peer reviewers selected represent a wide range of experience and knowledge particularly suitable for evaluating the subject matter. A total of 596 formal comments were documented by the seven peer review panels, and all were successfully resolved. The peers reached the conclusion that DOE/RW-0184, Rev. 1, is quality determined and suitable for use in quality-affecting work.

  15. The degradation of cellulose in the near field of a radioactive waste repository

    SciTech Connect

    Greenfield, B.F.; Hurdus, M.H.; Pilkington, N.J.; Spindler, M.W.; Williams, S.J.

    1994-12-31

    UK Nirex Ltd is seeking to develop a deep underground repository for the disposal of solid low- and intermediate-level radioactive wastes in the UK. The Nirex Safety Assessment Research Programme (NSARP) comprises scientific research to support the post-closure performance assessment of the repository. One of the investigations carried out by AEA Technology under the NSARP is the investigation of the formation of water-soluble complexants from the degradation of the solid organic polymers and cellulosic materials present in such wastes. The influence of these complexants on the solubility and sorption of a number of radionuclides is also being investigated by a combination of experimental measurements and thermodynamic modelling. Under the alkaline, anaerobic conditions representative of the near field of the repository, cellulose has previously been shown to degrade to yield soluble products which enhance the solubilities and reduce the sorption of several radionuclides. As part of this investigation, cellulose was chemically degraded under conditions similar to those expected in the near field and the leachate analysed. Separation of the products by HPLC gave direct identification of 2-C- (hydroxymethyl)-3-deoxy-D-erythro-pentonic (isosaccharinic) acid as one of the degradation products. More tentative assignments were made for glycolic, formic, lactic and acetic acids. A comparison was made with the degradation products suggested in the literature. The possible mechanisms and extent of cellulose degradation are discussed, as well as the factors affecting its degradation in the near field. The sorption of plutonium on to cement from a leachate produced under alkaline, anaerobic conditions is reported.

  16. Preliminary characterization of risks in the nuclear waste management system based on information in the literature

    SciTech Connect

    Daling, P.M.; Rhoads, R.E.; Van Luick, A.E.; Fecht, B.A.; Nilson, S.A.; Sevigny, N.L.; Armstrong, G.R.; Hill, D.H.; Rowe, M.; Stern, E.

    1992-01-01

    This document presents preliminary information on the radiological and nonradiological risks in the nuclear waste management system. The objective of the study was to (1) review the literature containing information on risks in the nuclear waste management system and (2) use this information to develop preliminary estimates of the potential magnitude of these risks. Information was collected on a broad range of risk categories to assist the US Department of Energy (DOE) in communicating information about the risks in the waste management systems. The study examined all of the portions of the nuclear waste management system currently expected to be developed by the DOE. The scope of this document includes the potential repository, the integral MRS facility, and the transportation system that supports the potential repository and the MRS facility. Relevant literature was reviewed for several potential repository sites and geologic media. A wide range of ``risk categories`` are addressed in this report: (1) public and occupational risks from accidents that could release radiological materials, (2) public and occupational radiation exposure resulting from routine operations, (3) public and occupational risks from accidents involving hazards other than radioactive materials, and (4) public and occupational risks from exposure to nonradioactive hazardous materials during routine operations. The report is intended to provide a broad spectrum of risk-related information about the waste management system. This information is intended to be helpful for planning future studies.

  17. Reference repository design concept for bedded salt

    SciTech Connect

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

    1980-10-08

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

  18. Geochemical properties of bentonite pore water in high-level-waste repository condition

    SciTech Connect

    Ohe, Toshiaki; Tsukamoto, Masaki

    1997-04-01

    The chemically favorable nature of bentonite pore water is clarified by the PHREEQE geochemical simulation code. Bentonite is viewed as a candidate buffer material for a high-level-waste repository, and bentonite`s pore water chemistry is expected to result in a reduced Eh and weak alkaline pH region. Pyrite (Fe{sub 2}S), initially contained in bentonite, alters to magnetite (Fe{sub 3}O{sub 4}), and this redox couple reaction controls the oxidation reduction potential. A mild alkaline pH condition is produced mainly by an ion exchange reaction between the sodium in bentonite and the protons in the solution. A geochemical simulation of the ion exchange reactions and the pyrite-magnetite alteration suggests that a favorable chemical condition would exist during the waste glass dissolution and indicates that the Ph and the Eh values are {minus}7.5 to {minus}9.4 and {minus}450 to {minus}320 mV, respectively, when the granitic groundwater intrudes into the compacted bentonite in the repository.

  19. Aspects of possible magmatic disruption of a high-level radioactive waste repository in southern Nevada

    SciTech Connect

    Crowe, B.; Amos, R.; Perry, F.; Self, S.; Vaniman, D.

    1982-10-01

    The Nevada Test Site (NTS) region is located within the central section of a north-northeast-trending basaltic volcanic belt of late Cenozoic age, a part of the Quaternary volcanic province of the Great Basin. Future volcanism within the belt represents a potential hazard to storage of high-level radioactive waste within a buried repository located in the southwestern NTS. The hazards of future volcanism in the region are being characterized through a combination of volcanic hazards studies, probability determinations, and consequence analyses. Basaltic activity within the NTS regions is divided into two age groups consisting of relatively large-volume silicic cycle basalts (8 to 10 Myr) and rift basalts (< 8 to 0.3 Myr). This paper describes the processes of basaltic magmatism ranging from derivation of basalt melts at depth, through ascent through the upper mantle and crust, to surface eruption. Each stage in the evolution and dispersal of basaltic magma is described, and the disruption and potential dispersal of stored radioactive waste is evaluated. These data document areas of knowns and unknowns in the processes of basaltic volcanisms and provide background data necessary to assist calculations of radiation release levels due to disruption of a repository. 9 figures, 11 tables.

  20. Management of Salt Waste from Electrochemical Processing of Used Nuclear Fuel

    SciTech Connect

    Michael F. Simpson; Michael N. Patterson; Joon Lee; Yifeng Wang; Joshua Versey; Ammon Williams; Supathorn Phongikaroon; James Allensworth; Man-Sung Yim

    2013-10-01

    Electrochemical processing of used nuclear fuel involves operation of one or more cells containing molten salt electrolyte. Processing of the fuel results in contamination of the salt via accumulation of fission products and transuranic (TRU) actinides. Upon reaching contamination limits, the salt must be removed and either disposed or treated to remove the contaminants and recycled back to the process. During development of the Experimental Breeder Reactor-II spent fuel treatment process, waste salt from the electrorefiner was to be stabilized in a ceramic waste form and disposed of in a high-level waste repository. With the cancellation of the Yucca Mountain high-level waste repository, other options are now being considered. One approach that involves direct disposal of the salt in a geologic salt formation has been evaluated. While waste forms such as the ceramic provide near-term resistance to corrosion, they may not be necessary to ensure adequate performance of the repository. To improve the feasibility of direct disposal, recycling a substantial fraction of the useful salt back to the process equipment could minimize the volume of the waste. Experiments have been run in which a cold finger is used for this purpose to crystallize LiCl from LiCl/CsCl. If it is found to be unsuitable for transportation, the salt waste could also be immobilized in zeolite without conversion to the ceramic waste form.

  1. Management of salt waste from electrochemical processing of used nuclear fuel

    SciTech Connect

    Simpson, M.F.; Patterson, M.N.; Lee, J.; Wang, Y.; Versey, J.; Phongikaroon, S.

    2013-07-01

    Electrochemical processing of used nuclear fuel involves operation of one or more cells containing molten salt electrolyte. Processing of the fuel results in contamination of the salt via accumulation of fission products and transuranic (TRU) actinides. Upon reaching contamination limits, the salt must be removed and either disposed or treated to remove the contaminants and recycled back to the process. During development of the Experimental Breeder Reactor-II spent fuel treatment process, waste salt from the electro-refiner was to be stabilized in a ceramic waste form and disposed of in a high-level waste repository. With the cancellation of the Yucca Mountain high-level waste repository, other options are now being considered. One approach that involves direct disposal of the salt in a geologic salt formation has been evaluated. While waste forms such as the ceramic provide near-term resistance to corrosion, they may not be necessary to ensure adequate performance of the repository. To improve the feasibility of direct disposal, recycling a substantial fraction of the useful salt back to the process equipment could minimize the volume of the waste. Experiments have been run in which a cold finger is used for this purpose to crystallize LiCl from LiCl/CsCl. If it is found to be unsuitable for transportation, the salt waste could also be immobilized in zeolite without conversion to the ceramic waste form. (authors)

  2. Plasma Mass Filters For Nuclear Waste Reprocessing

    SciTech Connect

    Abraham J. Fetterman and Nathaniel J. Fisch

    2011-05-25

    Practical disposal of nuclear waste requires high-throughput separation techniques. The most dangerous part of nuclear waste is the fission product, which contains the most active and mobile radioisotopes and produces most of the heat. We suggest that the fission products could be separated as a group from nuclear waste using plasma mass filters. Plasmabased processes are well suited to separating nuclear waste, because mass rather than chemical properties are used for separation. A single plasma stage can replace several stages of chemical separation, producing separate streams of bulk elements, fission products, and actinoids. The plasma mass filters may have lower cost and produce less auxiliary waste than chemical processing plants. Three rotating plasma configurations are considered that act as mass filters: the plasma centrifuge, the Ohkawa filter, and the asymmetric centrifugal trap.

  3. Plasma Mass Filters For Nuclear Waste Reprocessing

    SciTech Connect

    Abraham J. Fetterman and Nathaniel J. Fisch

    2011-05-26

    Practical disposal of nuclear waste requires high-throughput separation techniques. The most dangerous part of nuclear waste is the fission product, which contains the most active and mobile radioisotopes and produces most of the heat. We suggest that the fission products could be separated as a group from nuclear waste using plasma mass filters. Plasmabased processes are well suited to separating nuclear waste, because mass rather than chemical properties are used for separation. A single plasma stage can replace several stages of chemical separation, producing separate streams of bulk elements, fission products, and actinoids. The plasma mass filters may have lower cost and produce less auxiliary waste than chemical processing plants. Three rotating plasma configurations are considered that act as mass filters: the plasma centrifuge, the Ohkawa filter, and the asymmetric centrifugal trap.

  4. Science, Society, and America's Nuclear Waste: Nuclear Waste, Unit 1. Teacher Guide. Second Edition.

    ERIC Educational Resources Information Center

    Department of Energy, Washington, DC. Office of Civilian Radioactive Waste Management, Washington, DC.

    This guide is Unit 1 of the four-part series Science, Society, and America's Nuclear Waste produced by the U.S. Department of Energy's Office of Civilian Radioactive Waste Management. The goal of this unit is to help students establish the relevance of the topic of nuclear waste to their everyday lives and activities. Particular attention is…

  5. Coupling Legacy and Contemporary Deterministic Codes to Goldsim for Probabilistic Assessments of Potential Low-Level Waste Repository Sites

    NASA Astrophysics Data System (ADS)

    Mattie, P. D.; Knowlton, R. G.; Arnold, B. W.; Tien, N.; Kuo, M.

    2006-12-01

    project between Sandia National Laboratories and Taiwan's Institute of Nuclear Energy Research (INER) for the preliminary assessment of several candidate low-level waste repository sites. Sandia National Laboratories is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract DE AC04 94AL85000.

  6. Groundwater chemistry of a nuclear waste reposoitory in granite bedrock

    SciTech Connect

    Rydberg, J.

    1981-09-01

    This report concerns the prediction of the maximum dissolution rate for nuclear waste stored in the ground. That information is essential in judging the safety of a nuclear waste repository. With a limited groundwater flow, the maximum dissolution rate coincides with the maximum solubility. After considering the formation and composition of deep granite bedrock groundwater, the report discusses the maximum solubility in such groundwater of canister materials, matrix materials and waste elements. The parameters considered are pH, Eh and complex formation. The use of potential-pH (Pourbaix) diagrams is stressed; several appendixes are included to help in analyzing such diagrams. It is repeatedly found that desirable basic information on solution chemistry is lacking, and an international cooperative research effort is recommended. The report particularly stresses the lack of reliable data about complex formation and hydrolysis of the actinides. The Swedish Nuclear Fuel Safety (KBS) study has been used as a reference model. Notwithstanding the lack of reliable chemical data, particularly for the actinides and some fission products, a number of essential conclusions can be drawn about the waste handling model chosen by KBS. (1) Copper seems to be highly resistant to groundwater corrosion. (2) Lead and titanium are also resistant to groundwater, but inferior to copper. (3) Iron is not a suitable canister material. (4) Alumina (Al/sub 2/O/sub 3/) is not a suitable canister material if groundwater pH goes up to or above 10. Alumina is superior to copper at pH < 9, if there is a risk of the groundwater becoming oxidizing. (5) The addition of vivianite (ferrous phosphate) to the clay backfill around the waste canisters improves the corrosion resistance of the metal canisters, and reduces the solubility of many important waste elements. This report does not treat the migration of dissolved species through the rock.

  7. State-of-the-art for evaluating the potential impact of flooding on a radioactive waste repository

    SciTech Connect

    Not Available

    1980-07-16

    This report is a review of the state-of-the-art for evaluating the potential impact of flooding on a deep radioactive-waste repository, namely, for predicting the future occurrence of catastrophic flooding and for estimating the effect of such flooding on waste containment characteristics. Several detrimental effects are identified: flooding can increase groundwater seepage velocities through a repository within the framework of the existing hydrologic system and thus increase the rate of radioactive-waste leakage to the biosphere; flooding may alter repository hydrology by reversing flow gradients, relocating sources of groundwater recharge and discharge, or shortening seepage paths, thereby producing unpredictable leakage; saturation of a vadose-zone repository during flooding can increase groundwater seepage velocities by several orders of magnitude; and flooding can damage repository-media containment properties by inducing seismic or chemical instability or increasing fracture permeability in relatively shallow repository rock as a result of redistributing in-situ stresses. Short-term flooding frequency and magnitude can be predicted statistically by analyzing historical records of flooding. However, long-term flooding events that could damage a permanent repository cannot be predicted with confidence because the geologic record is neither unique nor sufficienly complete for statistical analysis. It is more important to identify parameters characterizing containment properties (such as permeability, groundwater gradient, and shortest seepage path length to the biosphere) that could be affected by future flooding, estimate the maximum magnitude of flooding that could occur within the life of the repository by examining the geologic record, and determine the impact such flooding could have on the parameter values.

  8. Crystallization behavior of nuclear waste forms

    SciTech Connect

    Rusin, J.M.; Lokken, R.O.; May, R.P.; Wald, J.W.

    1981-09-01

    Several waste form options have been or are being developed for the immobilization of high-level wastes. The final selection of a waste form must take into consideration both waste form product as well as process factors. Crystallization behavior has an important role in nuclear waste form technology. For glass or vitreous waste forms, crystallization is generally controlled to a minimum by appropriate glass formulation and heat treatment schedules. With glass ceramic waste forms, crystallization is essential to convert glass products to highly crystalline waste forms with a minimum residual glass content. In the case of ceramic waste forms, additives and controlled sintering schedules are used to contain the radionuclides in specific tailored crystalline phases.

  9. Site characterization plan: Yucca Mountain site, Nevada research and development area, Nevada: Consultation draft, Nuclear Waste Policy Act: Volume 4

    SciTech Connect

    1988-01-01

    The Yucca Mountain site in Nevada is one of three candidate sites for the first geologic repository for radioactive waste. On May 28, 1986, it was recommended and approved by the President for detailed study in a program of site characterization. This site characterization plan (SCP) has been prepared in accordance with the requirements of the Nuclear Waste Policy Act to summarize the information collected to date about the geologic conditions at the site; to describe the conceptual designs for the repository and the waste package; and to present the plans for obtaining the geologic information necessary to demonstate the suitability of the site for a repository, to desin the repository and the waste package, to prepare an environmental impact statement, and to obtain from the US Nuclear Regulatory Commission (NRC) an authorization to construct the repository. This introduction begins with a brief section on the process for siting and developing a repository, followed by a discussion of the pertinent legislation and regulations. A description of site characterization is presented next; it describes the facilities to be constructed for the site characterization program and explains the principal activities to be conducted during the program. Finally, the purpose, content, organizing principles, and organization of this site characterization plan are outlined, and compliance with applicable regulations is discussed.

  10. Site characterization plan: Yucca Mountain site, Nevada research and development area, Nevada: Consultation draft, Nuclear Waste Policy Act: Volume 7

    SciTech Connect

    1988-01-01

    The Yucca Mountain site in Neavada is one of three candidate sites for the first geologic repository for radioactive waste. On May 28, 1986, it was recommended and approved for detailed study in a program of site characterization. This site characterization plan (SCP) has been prepared in accordance with the requirements of the Nuclear Waste Policy Act to summarize the information collected to date about the geologic conditions at the site;to describe the conceptual designs for the repository and the waste package;and to present the plans for obtaining hte geologic information necessary to demonstrate the suitability of the site for a repository, to design the repository and the waste package, to prepare and environmental impact statement, and to obtain from the US Nuclear Regulatory Commission (NRC) an authorization to construct the repository. This introduction begins with a brief section on the process for siting and developing a repository, followed by a discussion of the pertinent legislation and regulations. A description of site characterization is presented next;it describes the facilities to be constructed for the site characterization program and explains the principal activities to be conducted during the program. Finally, the purpose, content, organizing principles, and organization of this site characterization plan are outlined, and compliance with applicable regulations is discussed.

  11. Site characterization plan: Yucca Mountain site, Nevada research and development area, Nevada: Consultation draft, Nuclear Waste Policy Act: Volume 1

    SciTech Connect

    1988-01-01

    The Yucca Mountain site in Nevada is one of three candidate sites for the first geologic repository for radioactive waste. On May 28, 1986, it was recommended for detailed study in a program of site characterization. This site characterization plan (SCP) has been prepared in acordance with the requirements of the Nuclear Waste Policy Act to summarize the information collected to date about the geologic conditions at the site;to describe the conceptual designs for the repository and the waste package and to present the plans for obtaining the geologic information necessary to demonstrate the suitability of the site for a repository, to design the repository and the waste package, to prepare an environmental impact statement, and to obtain from the US Nuclear Regulatory Commission (NRC) an authorization to construct the repository. This introduction begins with a brief section on the process for siting and eveloping a repository, followed by a discussion of the pertinent legislation and regulations. A description of site characterization is presented next;it describes the facilities to be constructed for the site characterization program and explains the principal activities to be conducted during the program. Finally, the purpose, content, organizing prinicples, and organization of this site characterization plan are outlined, and compliance with applicable regulations is discussed. 880 refs., 130 figs., 25 tabs.

  12. Site characterization plan: Yucca Mountain site, Nevada research and development area, Nevada: Consultation draft, Nuclear Waste Policy Act: Volume 6

    SciTech Connect

    1988-01-01

    The Yucca Mountain site in Nevada is one of three candidate sites for the first geologic repository for radioactive waste. On May 28, 1986, it was recommended for detailed study in a program of site characterization. This site characterization plan (SCP) has been prepared in accordance with the requirements of the Nuclear Waste Policy Act to summarize the information collected to date about the geologic conditions at the site;to describe the conceptual designs for the repository and the waste package;and to present the plans for obtaining the geologic information necessary to demonstrate the suitability of the site for repository, to design the repository and the waste package, to prepare an environmental impact statement, and to obtain from the US Nuclear Regulatory Commission (NRC) an authorization to construct the repository. This introduction begins with a brief section on the process for siting and developing a repository, followed by a discussion of the pertinent legislation and regulations. A description of site characterization is presented next;it describes the facilities to be constructed for the site characterization program and explains the principal activities to be conducted during the program. Finally, the purpose, content, organizing principles, and organization of this site characterization plan are outlined, and compliance with applicable regulations is discussed.

  13. Corrosion behavior of Alloy 22 in heated surface test conditions in simulated Yucca Mountain Nuclear Repository environment

    NASA Astrophysics Data System (ADS)

    Badwe, Sunil

    In the nuclear repository conditions, the nuclear waste package wall surfaces will be at elevated temperatures because of the heat generated by fission reactions within the waste. It is anticipated that the ground water may contain varying levels of anions such as chloride, nitrate, sulfate picked up from the rocks. The ground waters could seep through the rock faults and drip on to the waste packages. The dripped water will evaporate due to the heat from the nuclear waste leaving behind concentrated brine which eventually becomes dry salt deposit. The multi-ionic salts in the ground water are expected to be hygroscopic in nature. The next drop of water falling at the same place or the humidity in the repository will transform the hygroscopic salt deposit into a more concentrated brine. This cycle will continue for years and eventually a potentially corrosive brine will be formed on the waste package surface. Hence the waste package surface goes through the alternate wet-dry cycles. These conditions indicate that the concentration and pH of the environment in the repository vary considerably. The conventional corrosion tests hardly simulate these varying environmental conditions. Hence there has been a need to develop an electrochemical test that could closely simulate the anticipated repository conditions stated above. In this research, a new electrochemical method, called as Heated Surface Corrosion testing (HSCT) has been devised and tested. In the conventional testing the electrolyte is heated and in HSCT the working electrode is heated. The present study employs the temperature of 80°C which may be one of the temperatures of the waste package surface. The new HSCT was validated by testing stainless steel type 304. The HSCT was observed to be more aggressive than the conventional tests. Initiation of pitting of SS 304 in chloride solution (pH 3) occurred at much shorter exposure times in the HSCT condition than the exposure time required for pitting in

  14. Initial performance assessment of the disposal of spent nuclear fuel and high-level waste stored at Idaho National Engineering Laboratory. Volume 2: Appendices

    SciTech Connect

    Rechard, R.P.

    1993-12-01

    This performance assessment characterized plausible treatment options conceived by the Idaho National Engineering Laboratory (INEL) for its spent fuel and high-level radioactive waste and then modeled the performance of the resulting waste forms in two hypothetical, deep, geologic repositories: one in bedded salt and the other in granite. The results of the performance assessment are intended to help guide INEL in its study of how to prepare wastes and spent fuel for eventual permanent disposal. This assessment was part of the Waste Management Technology Development Program designed to help the US Department of Energy develop and demonstrate the capability to dispose of its nuclear waste, as mandated by the Nuclear Waste Policy Act of 1982. The waste forms comprised about 700 metric tons of initial heavy metal (or equivalent units) stored at the INEL: graphite spent fuel, experimental low enriched and highly enriched spent fuel, and high-level waste generated during reprocessing of some spent fuel. Five different waste treatment options were studied; in the analysis, the options and resulting waste forms were analyzed separately and in combination as five waste disposal groups. When the waste forms were studied in combination, the repository was assumed to also contain vitrified high-level waste from three DOE sites for a common basis of comparison and to simulate the impact of the INEL waste forms on a moderate-sized repository, The performance of the waste form was assessed within the context of a whole disposal system, using the U.S. Environmental Protection Agency`s Environmental Radiation Protection Standards for Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes, 40 CFR 191, promulgated in 1985. Though the waste form behavior depended upon the repository type, all current and proposed waste forms provided acceptable behavior in the salt and granite repositories.

  15. Approach to resolution of geologic uncertainty in the licensing of a high-level-waste repository in tuff

    SciTech Connect

    Neal, J.T.

    1983-12-31

    Resolution of uncertainty in geological information is an essential element in the licensing process for a geologic repository. Evaluation of these uncertainties within the licensing framework established by the Nuclear Regulatory Commission (NRC) is required. The Nevada Nuclear Waste Storage Investigations (NNWSI), in focusing its site characterization program on unsaturated tuff, has developed a logic hierarchy of technical issues, including key issues, issues, and information needs. Key issues are statements of major requirements whose lack could be disqualifying. An example of a key issue is the demonstration of radionuclide containment and isolation within the required release limits and transport time set by the EPA and NRC. Key issues are broken down into issues, such as the groundwater flow time to the accessible environment. Resolving uncertainty ultimately comes back to satisfying individual information needs that collectively form issues. Hydraulic conductivity is an example of an information need required to determine groundwater flow rate. Sources of uncertainty often arise in either amount, quality, or other limitations in geological data. The hierarchical structuring of geological information needs provides a perspective that allows proportionate attention to be placed on various site characterization activities, and to view them within the whole range of licensing issues that must be satisfied to ensure public health and safety. However, it may not prevent an issue from being contentious, as some geological questions are known to be emotion-laden. The mitigation of uncertainty in geological information ultimately will depend on the validity and credibility of the information presented during the licensing process.

  16. Monitor for detecting nuclear waste leakage in a subsurface repository

    SciTech Connect

    Klainer, S.; Hirschfeld, T.; Bowman, H.; Milanovich, F.; Perry, D.; Johnson, D.

    1980-11-05

    The remote fiber fluorimetric portion of the program is slightly ahead of schedule and proceeding well technically. Proof of principle has been demonstrated over a 0.2 km path length using an organic tracer material. Performance and design calculations have been made for the fiber optic components of the system. Optimized fibers have been ordered and special jigs and optical couplings are presently being fabricated. Progress on the high-sensitivity analyzer using coprecipitation techniques has proceeded well ahead of schedule with technical results far above expectations. Preliminary measurements in the UO/sub 2//sup 2 +//CaF/sub 2/ detection system has proved sensitivities well beyond the natural background limit. While further improvement of sensitivity (to 10/sup -15/ g) already is planned, emphasis will now be placed on locating and dealing with possible interferences and on determining how to improve and optimize quantitative accuracy. In addition, simplication of the sample preparation procedure and downscaling to use very small (< 1 ml) groundwater samples is planned. In the longer time frame, work on maximum chemical speciation and the possibility of isotopic speciation will be undertaken. Once the coprecipitation procedures, instrumentation, and spectroscopy have been fully refined for uranium, then the process will be repeated for plutonium and perhaps americium and thorium.

  17. Nuclear waste repository characterization: a spatial estimation/identification approach

    SciTech Connect

    Candy, J.V.; Mao, N.

    1981-03-01

    This paper considers the application of spatial estimation techniques to a groundwater aquifer and geological borehole data. It investigates the adequacy of these techniques to reliably develop contour maps from various data sets. The practice of spatial estimation is discussed and the estimator is then applied to a groundwater aquifer system and a deep geological formation. It is shown that the various statistical models must first be identified from the data and evaluated before reasonable results can be expected.

  18. ``Recycling'' Nuclear Power Plant Waste: Technical Difficulties and Proliferation Concerns

    NASA Astrophysics Data System (ADS)

    Lyman, Edwin

    2007-04-01

    One of the most vexing problems associated with nuclear energy is the inability to find a technically and politically viable solution for the disposal of long-lived radioactive waste. The U.S. plan to develop a geologic repository for spent nuclear fuel at Yucca Mountain in Nevada is in jeopardy, as a result of managerial incompetence, political opposition and regulatory standards that may be impossible to meet. As a result, there is growing interest in technologies that are claimed to have the potential to drastically reduce the amount of waste that would require geologic burial and the length of time that the waste would require containment. A scenario for such a vision was presented in the December 2005 Scientific American. While details differ, these technologies share a common approach: they require chemical processing of spent fuel to extract plutonium and other long-lived actinide elements, which would then be ``recycled'' into fresh fuel for advanced reactors and ``transmuted'' into shorter-lived fission products. Such a scheme is the basis for the ``Global Nuclear Energy Partnership,'' a major program unveiled by the Department of Energy (DOE) in early 2006. This concept is not new, but has been studied for decades. Major obstacles include fundamental safety issues, engineering feasibility and cost. Perhaps the most important consideration in the post-9/11 era is that these technologies involve the separation of plutonium and other nuclear weapon-usable materials from highly radioactive fission products, providing opportunities for terrorists seeking to obtain nuclear weapons. While DOE claims that it will only utilize processes that do not produce ``separated plutonium,'' it has offered no evidence that such technologies would effectively deter theft. It is doubtful that DOE's scheme can be implemented without an unacceptable increase in the risk of nuclear terrorism.

  19. Development of models for use in the assessment of waste repository performance

    SciTech Connect

    Dickson, A.G.; Weare, J.H. )

    1989-09-01

    The work outlined in this proposal is intended both to provide thermodynamic data that is needed to assist in the assessment of waste repository performance and the modeling necessary to ascertain to what extent the data produced is consistent, both with itself and with other published data on related systems. During this stage of the research we shall endeavor to develop a model of the chemistry of aluminum in aqueous solution which is consistent with a wide variety of experimental data including data generated as part of this project together with data that has been published previously in the research literature. We propose a program of research designed to enable us to model the interaction of canister materials (e.g. copper and iron) with natural waters. Both experimental work and a modeling program are outlined. In the experimental program e.m.f. measurements and spectroscopic measurements will be made so as to determine the various association equilibria of iron and copper with the anions OH{minus}, HCO{sub 3}{sup {minus}}, and CO{sub 3}{sup 2{minus}}. The initial stages of the modeling program will concentrate on the identification and use of existing experimental data to produce a preliminary model. This will allow us to identify those areas where special emphasis should be placed to meet the needs of the waste disposal program objectives. The objective of this research is to produce thermodynamic data for use in the assessment of waste repository performance that has been measured using experimental procedures performed in accord with the Level 1 quality assurance requirements detailed in the L.L.N.L. Yucca Mountain Project Quality Procedures Manual. The modeling approach used in experimental planning and data assessment is a Level 3 activity. In addition to the establishment of the thermodynamic data base proposed here, results should lead to improved consistency in the overall modeling effort. 29 refs., 2 tabs.

  20. Scientific studies in support of the Waste Isolation Pilot Plant (WIPP) repository

    SciTech Connect

    Chu, M.S.Y.; Weart, W.D.

    1996-12-31

    The DOE submitted a Compliance Certification Application for WIPP in october, 1996. A critical part of this application was a Performance Assessment which predicts the cumulative radioactive release to the accessible environment over a time period of 10,000 years. Comparison of this predicted release to the EPA standard shows a comfortable margin of compliance. The scientific understanding that was critical to developing this assessment spans a broad range of geotechnical disciplines, and required a thorough understanding of the site`s geology and hydrology. Evaluation of the geologic processes which are active in the site region establishes that there will be no natural breach of site integrity for millions of years, far longer than the 10,000 year regulatory period. Inadvertent human intrusion is, therefore, the only credible scenario to lead to potential radioactive release to the accessible environment. To substantiate this conclusion and to quantify these potential releases from human intrusion, it has been necessary to develop an understanding of the following processes: salt creep and shaft seal efficacy; gas generation from organic decomposition of waste materials and anoxic corrosion of metals in the waste and waste packages; solubilities for actinides in brine; fluid flow in Salado formation rocks, and hydrologic transport of actinides in the overlying dolomite aquifers. Other issues which had to be evaluated to allow definition of breach scenarios were brine reservoir occurrences and their associated reservoir parameters, consequences of mining over the repository, and drilling for natural resources in the vicinity of the repository. Results of all these studies will be briefly summarized in this paper.

  1. Nuclear Energy Advanced Modeling and Simulation Waste Integrated Performance and Safety Codes (NEAMS Waste IPSC).

    SciTech Connect

    Schultz, Peter Andrew

    2011-12-01

    The objective of the U.S. Department of Energy Office of Nuclear Energy Advanced Modeling and Simulation Waste Integrated Performance and Safety Codes (NEAMS Waste IPSC) is to provide an integrated suite of computational modeling and simulation (M&S) capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive-waste storage facility or disposal repository. Achieving the objective of modeling the performance of a disposal scenario requires describing processes involved in waste form degradation and radionuclide release at the subcontinuum scale, beginning with mechanistic descriptions of chemical reactions and chemical kinetics at the atomic scale, and upscaling into effective, validated constitutive models for input to high-fidelity continuum scale codes for coupled multiphysics simulations of release and transport. Verification and validation (V&V) is required throughout the system to establish evidence-based metrics for the level of confidence in M&S codes and capabilities, including at the subcontiunuum scale and the constitutive models they inform or generate. This Report outlines the nature of the V&V challenge at the subcontinuum scale, an approach to incorporate V&V concepts into subcontinuum scale modeling and simulation (M&S), and a plan to incrementally incorporate effective V&V into subcontinuum scale M&S destined for use in the NEAMS Waste IPSC work flow to meet requirements of quantitative confidence in the constitutive models informed by subcontinuum scale phenomena.

  2. Commercial nuclear reactors and waste: the current status

    SciTech Connect

    Platt, A.M.; Robinson, J.V.

    1980-04-01

    During the last five years, the declared size of the commercial light water reactor (LWR) nuclear power industry in the US has steadily decreased. As of January 1980, the total number of power plants had dropped to 191 from the 226 in December 31, 1974. At least another nine were cancelled in the last few months. This report was developed as the first of a series to track implications to waste management due to such changes in the declared size of the industry. For the presently declared size, key conclusions are: the declared reactors will peak at a capacity of 162 GWe and consume about 10/sup 6/ MTU as enrichment feed. As few as two repositories of about 100,000 MTHM capacity each would hold the waste. Predisposal storage (reactor basins and AFRs) would peak at less than 100,000 MTHM (in the year 2020) with one repository opening in the year 1997 and the other in the year 2020. Most of the 100,000 MTHM would have to be in AFR storage unless current practice regarding reactor basin size was radically changed.

  3. Nuclear waste disposal: The technical challenges

    SciTech Connect

    Crowley, K.D.

    1997-06-01

    Public safety and billions of taxpayer dollars are at stake in the efforts to solve formidable technical problems associated with the disposal of spent nuclear fuel and defense waste.{copyright} {ital 1997 American Institute of Physics.}

  4. 10 CFR 1.18 - Advisory Committee on Nuclear Waste.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Advisory Committee on Nuclear Waste. 1.18 Section 1.18... Panels, Boards, and Committees § 1.18 Advisory Committee on Nuclear Waste. The Advisory Committee on Nuclear Waste (ACNW) provides advice to the Commission on all aspects of nuclear waste management,...

  5. Source term evaluation model for high-level radioactive waste repository with decay chain build-up.

    PubMed

    Chopra, Manish; Sunny, Faby; Oza, R B

    2016-09-18

    A source term model based on two-component leach flux concept is developed for a high-level radioactive waste repository. The long-lived radionuclides associated with high-level waste may give rise to the build-up of activity because of radioactive decay chains. The ingrowths of progeny are incorporated in the model using Bateman decay chain build-up equations. The model is applied to different radionuclides present in the high-level radioactive waste, which form a part of decay chains (4n to 4n + 3 series), and the activity of the parent and daughter radionuclides leaching out of the waste matrix is estimated. Two cases are considered: one when only parent is present initially in the waste and another where daughters are also initially present in the waste matrix. The incorporation of in situ production of daughter radionuclides in the source is important to carry out realistic estimates. It is shown that the inclusion of decay chain build-up is essential to avoid underestimation of the radiological impact assessment of the repository. The model can be a useful tool for evaluating the source term of the radionuclide transport models used for the radiological impact assessment of high-level radioactive waste repositories. PMID:27337157

  6. Source term evaluation model for high-level radioactive waste repository with decay chain build-up.

    PubMed

    Chopra, Manish; Sunny, Faby; Oza, R B

    2016-09-18

    A source term model based on two-component leach flux concept is developed for a high-level radioactive waste repository. The long-lived radionuclides associated with high-level waste may give rise to the build-up of activity because of radioactive decay chains. The ingrowths of progeny are incorporated in the model using Bateman decay chain build-up equations. The model is applied to different radionuclides present in the high-level radioactive waste, which form a part of decay chains (4n to 4n + 3 series), and the activity of the parent and daughter radionuclides leaching out of the waste matrix is estimated. Two cases are considered: one when only parent is present initially in the waste and another where daughters are also initially present in the waste matrix. The incorporation of in situ production of daughter radionuclides in the source is important to carry out realistic estimates. It is shown that the inclusion of decay chain build-up is essential to avoid underestimation of the radiological impact assessment of the repository. The model can be a useful tool for evaluating the source term of the radionuclide transport models used for the radiological impact assessment of high-level radioactive waste repositories.

  7. Robotics and remote handling concepts for disposal of high-level nuclear waste

    SciTech Connect

    McAffee, Douglas; Raczka, Norman; Schwartztrauber, Keith

    1997-04-27

    This paper summarizes preliminary remote handling and robotic concepts being developed as part of the US Department of Energy's (DOE) Yucca Mountain Project. The DOE is currently evaluating the Yucca Mountain Nevada site for suitability as a possible underground geologic repository for the disposal of high level nuclear waste. The current advanced conceptual design calls for the disposal of more than 12,000 high level nuclear waste packages within a 225 km underground network of tunnels and emplacement drifts. Many of the waste packages may weigh as much as 66 tonnes and measure 1.8 m in diameter and 5.6 m long. The waste packages will emit significant levels of radiation and heat. Therefore, remote handling is a cornerstone of the repository design and operating concepts. This paper discusses potential applications areas for robotics and remote handling technologies within the subsurface repository. It also summarizes the findings of a preliminary technology survey which reviewed available robotic and remote handling technologies developed within the nuclear, mining, rail and industrial robotics and automation industries, and at national laboratories, universities, and related research institutions and government agencies.

  8. Solid wastes from nuclear power production.

    PubMed Central

    Soule, H F

    1978-01-01

    Radioactivity in nuclear power effluents is negligible compared to that in retained wastes to be disposed of as solids. Two basic waste categories are those for which shallow disposal is accepted and those for which more extreme isolation is desired. The latter includes "high level" wastes and others contaminated with radionuclides with the unusual combined properties of long radioactive half-life and high specific radiotoxicity. The favored method for extreme isolation is emplacement in a deep stable geologic formation. Necessary technologies for waste treatment and disposal are considered available. The present program to implement these technologies is discussed, including the waste management significance of current policy on spent nuclear fuel reprocessing. Recent difficulties with shallow disposal of waste are summarized. PMID:738244

  9. Challenges in Uncertainty and the Science of Nuclear Waste Disposal (Invited)

    NASA Astrophysics Data System (ADS)

    Alley, W. M.; Alley, R.

    2013-12-01

    Disposal of high-level nuclear waste is a first-of-a-kind endeavor, further saddled by the ambitious goal to achieve containment over periods well beyond human experience. In the United States, as well as other countries, the time period for performance assessment to provide a safety case for deep geologic repositories has gone from 10,000 years in the 1990s to one million years today. Even when the standard was established for 10,000 years, the National Academy of Sciences Board on Radioactive Waste Management warned of the 'scientific trap' set by encouraging the public to expect certainty about repository safety well beyond what science can provide. Paradoxically, the emphasis on predicting repository behavior thousands of centuries into the future stands in stark contrast to a lack of risk assessment of indefinite aboveground storage for the next several generations. We review the uncertainties and technical basis for a geologic repository at Yucca Mountain compared to extended onsite and interim storage. In order to make progress with geologic disposal of nuclear waste, it is important to evaluate any option in the context of the relative merits and limitations of alternative geologic settings, interim storage, and the status quo of extended onsite storage.

  10. Nevada Nuclear-Waste-Storage Investigations. Quarterly report, April-June 1982

    SciTech Connect

    1982-09-01

    The Nevada Nuclear Waste Storage Investigations (NNWSI) are studying the Nevada Test Site (NTS) area to establish whether it would qualify as a licensable location for a commercial nuclear waste repository; determining whether specific underground rock masses in the NTS area are technically acceptable for permanently disposing of highly radioactive solid wastes; and developing and demonstrating the capability to safely handle and store commercial spent reactor fuel and high-level waste. Progress reports for the following eight tasks are presented: systems; waste package; site; repository; regulatory and institutional; test facilities; land acquisition; and program management. Some of the highlights are: A code library was established to provide a central location for documentation of repository performance assessment codes. A two-dimensional finite element code, SAGUARO, was developed for modeling saturated/unsaturated groundwater flow. The results of an initial experiment to determine canister penetration rates due to corrosion indicate the expected strong effect of toxic environmental conditions on the corrosion rate of carbon steel in tuff-conditioned water. Wells USW-H3 and USW-H4 at Yucca Mountain have been sampled for groundwater analysis. A summary characterizing and relating the mineralogy and petrology of Yucca Mountain tuffs was compiled from the findings of studies of core samples from five drill holes.

  11. Nuclear waste: distant and expensive mirage

    SciTech Connect

    2008-08-15

    The situation in the U.S. regarding the disposal of nuclear waste is briefly summarized. Current estimates are that the site will not begin operation before 2020, and that the cost will be $96 billion, which includes construction, waste transport, operation through 2133, and closure of the facility. The Department of Energy is also considering whether more disposal sites might be needed.

  12. Nuclear Waste Primer: A Handbook for Citizens.

    ERIC Educational Resources Information Center

    Weber, Isabelle P.; Wiltshire, Susan D.

    This publication was developed with the intention of offering the nonexpert a concise, balanced introduction to nuclear waste. It outlines the dimensions of the problem, discussing the types and quantities of waste. Included are the sources, types, and hazards of radiation, and some of the history, major legislation, and current status of both…

  13. Statistical process control: An approach to quality assurance in the production of vitrified nuclear waste

    SciTech Connect

    Pulsipher, B.A.; Kuhn, W.L.

    1987-02-01

    Current planning for liquid high-level nuclear wastes existing in the US includes processing in a liquid-fed ceramic melter to incorporate it into a high-quality glass, and placement in a deep geologic repository. The nuclear waste vitrification process requires assurance of a quality product with little or no final inspection. Statistical process control (SPC) is a quantitative approach to one quality assurance aspect of vitrified nuclear waste. This method for monitoring and controlling a process in the presence of uncertainties provides a statistical basis for decisions concerning product quality improvement. Statistical process control is shown to be a feasible and beneficial tool to help the waste glass producers demonstrate that the vitrification process can be controlled sufficiently to produce an acceptable product. This quantitative aspect of quality assurance could be an effective means of establishing confidence in the claims to a quality product. 2 refs., 4 figs.

  14. Handling glacially induced faults in the assessment of the long term safety of a repository for spent nuclear fuel at Forsmark, Sweden

    NASA Astrophysics Data System (ADS)

    Munier, R.

    2011-12-01

    Located deep into the Baltic shield, far from active plate boundaries and volcanism, Swedish bedrock is characterised by a low frequency of earthquakes of small magnitudes. Yet, faults, predominantly in the Lapland region, offsetting the quarternary regolith ten meters or more, reveal that Swedish bedrock suffered from substantial earthquake activity in connection to the retreat of the latest continental glacier, Weichsel. Storage of nuclear wastes, hazardous for hundreds of thousand years, requires, firstly, isolation of radionuclides and, secondly, retardation of the nuclides should the barriers fail. Swedish regulations require that safety is demonstrated for a period of a million years. Consequently, the repository must be designed to resist the impact of several continental glaciers. Large, glacially induced, earthquakes near the repository have the potential of triggering slip along fractures across the canisters containing the nuclear wastes, thereby simultaneously jeopardising isolation, retardation and, hence, long term safety. It has therefore been crucial to assess the impact of such intraplate earthquake upon the primary functions of the repository. We conclude that, by appropriate design of the repository, the negative impact of earthquakes on long term safety can be considerably lessened. We were, additionally, able to demonstrate compliance with Swedish regulations in our safety assessment, SR-Site, submitted to the authorities earlier this year. However, the assessment required a number of critical assumptions, e.g. concerning the strain rate and the fracture properties of the rock, many of which are subject of current research in the geoscientific community. By a conservative approach, though, we judge to have adequately propagated critical uncertainties through the assessment and bound the uncertainty space.

  15. Project characteristics monitoring report: BWIP (Basalt Waste Isolation Program) repository project

    SciTech Connect

    Friedli, E.A.; Herborn, D.I.; Taylor, C.D.; Tomlinson, K.M.

    1988-03-01

    This monitoring report has been prepared to show compliance with provisions of the Nuclear Waste Policy Act of 1982 (NWPA) and to provide local and state government agencies with information concerning the Basalt Waste Isolation Program (BWIP). This report contains data for the time period May 26, 1986 to February 1988. The data include employment figures, salaries, project purchases, taxes and fees paid, worker survey results, and project closedown personal interview summaries. This information has become particularly important since the decision in December 1987 to stop all BWIP activities except those for site reclamation. The Nuclear Waste Policy Amendments Act of 1987 requires nonreclamation work at the Hanford Site to stop as of March 22, 1988. 7 refs., 6 figs., 28 tabs.

  16. Calcine Waste Storage at the Idaho Nuclear Technology and Engineering Center

    SciTech Connect

    Staiger, Merle Daniel; M. C. Swenson

    2005-01-01

    This report documents an inventory of calcined waste produced at the Idaho Nuclear Technology and Engineering Center during the period from December 1963 to May 2000. The report was prepared based on calciner runs, operation of the calcined solids storage facilities, and miscellaneous operational information that establishes the range of chemical compositions of calcined waste stored at Idaho Nuclear Technology and Engineering Center. The report will be used to support obtaining permits for the calcined solids storage facilities, possible treatment of the calcined waste at the Idaho National Engineering and Environmental Laboratory, and to ship the waste to an off-site facility including a geologic repository. The information in this report was compiled from calciner operating data, waste solution analyses and volumes calcined, calciner operating schedules, calcine temperature monitoring records, and facility design of the calcined solids storage facilities. A compact disk copy of this report is provided to facilitate future data manipulations and analysis.

  17. Natural analogues of nuclear waste glass corrosion.

    SciTech Connect

    Abrajano, T.A. Jr.; Ebert, W.L.; Luo, J.S.

    1999-01-06

    This report reviews and summarizes studies performed to characterize the products and processes involved in the corrosion of natural glasses. Studies are also reviewed and evaluated on how well the corrosion of natural glasses in natural environments serves as an analogue for the corrosion of high-level radioactive waste glasses in an engineered geologic disposal system. A wide range of natural and experimental corrosion studies has been performed on three major groups of natural glasses: tektite, obsidian, and basalt. Studies of the corrosion of natural glass attempt to characterize both the nature of alteration products and the reaction kinetics. Information available on natural glass was then compared to corresponding information on the corrosion of nuclear waste glasses, specifically to resolve two key questions: (1) whether one or more natural glasses behave similarly to nuclear waste glasses in laboratory tests, and (2) how these similarities can be used to support projections of the long-term corrosion of nuclear waste glasses. The corrosion behavior of basaltic glasses was most similar to that of nuclear waste glasses, but the corrosion of tektite and obsidian glasses involves certain processes that also occur during the corrosion of nuclear waste glasses. The reactions and processes that control basalt glass dissolution are similar to those that are important in nuclear waste glass dissolution. The key reaction of the overall corrosion mechanism is network hydrolysis, which eventually breaks down the glass network structure that remains after the initial ion-exchange and diffusion processes. This review also highlights some unresolved issues related to the application of an analogue approach to predicting long-term behavior of nuclear waste glass corrosion, such as discrepancies between experimental and field-based estimates of kinetic parameters for basaltic glasses.

  18. Radiation Effects in Nuclear Waste Materials

    SciTech Connect

    Weber, William J.

    2005-09-30

    The objective of this project is to develop a fundamental understanding of radiation effects in glasses and ceramics, as well as the influence of solid-state radiation effects on aqueous dissolution kinetics, which may impact the performance of nuclear waste forms and stabilized nuclear materials. This work provides the underpinning science to develop improved glass and ceramic waste forms for the immobilization and disposition of high-level tank waste, excess plutonium, plutonium residues and scrap, other actinides, and other nuclear waste streams. Furthermore, this work is developing develop predictive models for the performance of nuclear waste forms and stabilized nuclear materials. Thus, the research performed under this project has significant implications for the immobilization of High-Level Waste (HLW) and Nuclear Materials, two mission areas within the Office of Environmental Management (EM). With regard to the HLW mission, this research will lead to improved understanding of radiation-induced degradation mechanisms and their effects on dissolution kinetics, as well as development of predictive models for waste form performance. In the Nuclear Materials mission, this research will lead to improvements in the understanding of radiation effects on the chemical and structural properties of materials for the stabilization and long-term storage of plutonium, highly-enriched uranium, and other actinides. The research uses plutonium incorporation, ion-beam irradiation, and electron-beam irradiation to simulate the effects of alpha decay and beta decay on relevant glasses and ceramics. The research under this project has the potential to result in improved glass and ceramic materials for the stabilization and immobilization of high-level tank waste, plutonium residues and scraps, surplus weapons plutonium, highly-enriched uranium, other actinides, and other radioactive materials.

  19. Radiation Effects in Nuclear Waste Materials

    SciTech Connect

    Weber, William J.

    2005-06-01

    The objective of this project is to develop a fundamental understanding of radiation effects in glasses and ceramics, as well as the influence of solid-state radiation effects on aqueous dissolution kinetics, which may impact the performance of nuclear waste forms and stabilized nuclear materials. This work provides the underpinning science to develop improved glass and ceramic waste forms for the immobilization and disposition of high-level tank waste, excess plutonium, plutonium residues and scrap, other actinides, and other nuclear waste streams. Furthermore, this work is developing develop predictive models for the performance of nuclear waste forms and stabilized nuclear materials. Thus, the research performed under this project has significant implications for the immobilization of High-Level Waste (HLW) and Nuclear Materials, two mission areas within the Office of Environmental Management (EM). With regard to the HLW mission, this research will lead to improved understanding of radiation-induced degradation mechanisms and their effects on dissolution kinetics, as well as development of predictive models for waste form performance. In the Nuclear Materials mission, this research will lead to improvements in the understanding of radiation effects on the chemical and structural properties of materials for the stabilization and long-term storage of plutonium, highly-enriched uranium, and other actinides. The research uses plutonium incorporation, ion-beam irradiation, and electron-beam irradiation to simulate the effects of alpha decay and beta decay on relevant glasses and ceramics. The research under this project has the potential to result in improved glass and ceramic materials for the stabilization and immobilization of high-level tank waste, plutonium residues and scraps, surplus weapons plutonium, highly-enriched uranium, other actinides, and other radioactive materials.

  20. Underground collocation of nuclear power plant reactors and repository to facilitate the post-renaissance expansion of nuclear power

    SciTech Connect

    Myers, Carl W; Elkins, Ned Z

    2008-01-01

    Underground collocation of nuclear power reactors and the nuclear waste management facilities supporting those reactors, termed an underground nuclear park (UNP), appears to have several advantages compared to the conventional approach to siting reactors and waste management facilities. These advantages include the potential to lower reactor capital and operating cost, lower nuclear waste management cost, and increase margins of physical security and safety. Envirorunental impacts related to worker health, facility accidents, waste transportation, and sabotage and terrorism appear to be lower for UNPs compared to the current approach. In-place decommissioning ofUNP reactors appears to have cost, safety, envirorunental and waste disposal advantages. The UNP approach has the potential to lead to greater public acceptance for the deployment of new power reactors. Use of the UNP during the post-nuclear renaissance time frame has the potential to enable a greater expansion of U.S. nuclear power generation than might otherwise result. Technical and economic aspects of the UNP concept need more study to determine the viability of the concept.

  1. Initial performance assessment of the disposal of spent nuclear fuel and high-level waste stored at Idaho National Engineering Laboratory. Volume 1, Methodology and results

    SciTech Connect

    Rechard, R.P.

    1993-12-01

    This performance assessment characterized plausible treatment options conceived by the Idaho National Engineering Laboratory (INEL) for its spent fuel and high-level radioactive waste and then modeled the performance of the resulting waste forms in two hypothetical, deep, geologic repositories: one in bedded salt and the other in granite. The results of the performance assessment are intended to help guide INEL in its study of how to prepare wastes and spent fuel for eventual permanent disposal. This assessment was part of the Waste Management Technology Development Program designed to help the US Department of Energy develop and demonstrate the capability to dispose of its nuclear waste. Although numerous caveats must be placed on the results, the general findings were as follows: Though the waste form behavior depended upon the repository type, all current and proposed waste forms provided acceptable behavior in the salt and granite repositories.

  2. Doing the impossible: Recycling nuclear waste

    ScienceCinema

    None

    2016-07-12

    A Science Channel feature explores how Argonne techniques could be used to safely reduce the amount of radioactive waste generated by nuclear power—the most plentiful carbon-neutral energy source. Read more at http://www.anl.gov/Media_Center/ArgonneNow/Fall_2009/nuclear.html

  3. Radiation Effects in Nuclear Waste Materials

    SciTech Connect

    William j. Weber; Lumin Wang; Jonathan Icenhower

    2004-07-09

    The objective of this project is to develop a fundamental understanding of radiation effects in glasses and ceramics, as well as the influence of solid-state radiation effects on aqueous dissolution kinetics, which may impact the performance of nuclear waste forms and stabilized nuclear materials.

  4. A report on the status of hydrothermal testing of fully radioactive waste forms and basalt repository waste package components

    SciTech Connect

    Schramke, J.A.; Simonson, S.A.; Coles, D.G.

    1984-09-01

    Initial experiments to investigate the hydrothermal behavior to basalt repository constitutents including fully radioactive waste forms have been terminated. Solutions from these three experiments have been analyzed to gather data on the concentrations of radionuclides carried in solution as a function of time through the duration of each run. Two runs contained ATM-6 glass with groundwater; one of these with basalt, one without. Turkey Point spent fuel and groundwater comprised the third experiment. In the glass experiments, which allow comparison to demonstrate the effect of basalt, several trends were noted. Dissolved silica was lower with basalt than without; pH increased slightly in the presence of basalt; concentrations in the water of {sup 99}T{sub c}, {sup 75}{sub Se}, {sup 137}Cs were less with basalt than without, actinide concentration in water was lower than the calculated value. The latter two imply that these radionuclides were either adsorbed or precipitated in secondary phases. The experiment using spent fuel also demonstrates that radionuclide concentrations in solution are much less than calculated by the amount of the waste form dissolved. Again this implies that radionuclides released from the waste form are removed from the water and immobilized.

  5. Proceedings of the symposium on Scientific Basis for Nuclear Waste Management XXX

    SciTech Connect

    Dunn, Darrell; Poinssot, Christophe; Begg, Bruce

    2007-07-01

    Management of nuclear waste remains an important international topic that includes reprocessing of commercial nuclear fuel, waste-form design and development, storage and disposal packaging, the process of repository site selection, system design, and performance assessment. Requirements to manage and dispose of materials from the production of nuclear weapons, and the renewed interest in nuclear power, in particular through the Generation IV Forum and the Advanced Fuel Cycle Initiative, can be expected to increase the need for scientific advances in waste management. A broad range of scientific and engineering disciplines is necessary to provide safe and effective solutions and address complex issues. This volume offers an interdisciplinary perspective on materials-related issues associated with nuclear waste management programs. Invited and contributed papers cover a wide range of topics including studies on: spent fuel; performance assessment and models; waste forms for low- and intermediate-level waste; ceramic and glass waste forms for plutonium and high-level waste; radionuclides; containers and engineered barriers; disposal environments and site characteristics; and partitioning and transmutation.

  6. Technology of high-level nuclear waste disposal. Advances in the science and engineering of the management of high-level nuclear wastes. Volume 1

    SciTech Connect

    Hofmann, P.L.; Breslin, J.J.

    1981-01-01

    The papers in this volume cover the following subjects: waste isolation and the natural geohydrologic system; repository perturbations of the natural system; radionuclide migration through the natural system; and repository design technology. Individual papers are abstracted.

  7. Site characterization plan: Yucca Mountain site, Nevada research and development area, Nevada: Consultation draft, Nuclear Waste Policy Act

    SciTech Connect

    1988-01-01

    The Yucca Mountain site in Nevada is one of three candidate sites for the first geologic repository for radioactive waste. On May 28, 1986, it was recommended by the Secretary of Energy and approved by the President for detailed study in a program of site characterization. This site characterization plan (SCP) has been prepared by the US Department of Energy (DOE) in accordance with the requirements of the Nulcear Waste Policy Act to summarize the information collected to date about the geologic conditions at the site;to describe the conceptual designs for the repository and the waste package;and to present the plans for obtaining the geologic information necessary to demonstrate the suitability of the site for a repository, to design the repository and the waste package, to prepare an environmental impact statement, and to obtain from the US Nuclear Regulatory Commission (NRC) an authorization to construct the repository. This introduction begins with a brief section on the process for siting and developing a repository, followed by a discussion of the pertinent legislation and regulations. A description of site characterization is presented next;it describes the facilities to be constructed for the site characterization program and explains the principal activities to be conducted during the program. Finally, the purpose, content, organizing principles, and organization of the site characterization plan are oulined, and compliance with applicable regulations is discussed.

  8. Nuclear waste incineration technology status

    SciTech Connect

    Ziegler, D.L.; Lehmkuhl, G.D.; Meile, L.J.

    1981-07-15

    The incinerators developed and/or used for radioactive waste combustion are discussed and suggestions are made for uses of incineration in radioactive waste management programs and for incinerators best suited for specific applications. Information on the amounts and types of radioactive wastes are included to indicate the scope of combustible wastes being generated and in existence. An analysis of recently developed radwaste incinerators is given to help those interested in choosing incinerators for specific applications. Operating information on US and foreign incinerators is also included to provide additional background information. Development needs are identified for extending incinerator applications and for establishing commercial acceptance.

  9. Significance of 14C and 228Ra in terms of the proposed Yucca Mountain high-level radioactive waste repository.

    PubMed

    Moeller, Dade W; Ryan, Michael T; Cherry, Robert N; Sun, Lin-Shen C

    2006-09-01

    C and Ra are two of the radionuclides that have either been identified as being potentially significant in terms of releases from the proposed Yucca Mountain high-level radioactive waste repository, or are specifically cited for consideration and evaluation in the regulations promulgated by the U.S. Nuclear Regulatory Commission. The purpose of this study was to estimate the concentrations and associated doses for these two radionuclides, if released under conditions of a scenario assumed to apply to a repository containing some of the features of the one proposed at Yucca Mountain, NV, and to compare these estimates to the regulatory limits for that facility. For C, the postulated condition was that an annual fractional release of 10 of its total remaining inventory occurs beginning at 10,000 y after repository closure. For Ra, the same fractional release rate was assumed, but in this case it was presumed to occur when the Ra inventory was projected to reach a maximum at more than 10 y after repository closure. The estimated concentrations and doses were, in turn, compared to the concentration limit, specified in the Ground Water Protection Standards (GWPSs) in the case of Ra, or derived, in the case of C, on the basis of the regulatory dose rate limit. Due to the small inventory of C in the waste, and its short half-life relative to the performance period evaluated, its estimated concentration in the ground water would be slightly more than 4% of the derived GWPS. Due to the relatively small initial inventory of Th, the precursor of Ra, and the correspondingly small quantities of higher atomic number actinides that could, through decay, produce additional quantities of Th, its estimated concentration in the ground water would be less than 3% of the GWPS, leaving the remaining portion of the limit for potential contributions from Ra. At the same time, however, it must be recognized that, in this case, the regulations require that any contributions of naturally

  10. Significance of 14C and 228Ra in terms of the proposed Yucca Mountain high-level radioactive waste repository.

    PubMed

    Moeller, Dade W; Ryan, Michael T; Cherry, Robert N; Sun, Lin-Shen C

    2006-09-01

    C and Ra are two of the radionuclides that have either been identified as being potentially significant in terms of releases from the proposed Yucca Mountain high-level radioactive waste repository, or are specifically cited for consideration and evaluation in the regulations promulgated by the U.S. Nuclear Regulatory Commission. The purpose of this study was to estimate the concentrations and associated doses for these two radionuclides, if released under conditions of a scenario assumed to apply to a repository containing some of the features of the one proposed at Yucca Mountain, NV, and to compare these estimates to the regulatory limits for that facility. For C, the postulated condition was that an annual fractional release of 10 of its total remaining inventory occurs beginning at 10,000 y after repository closure. For Ra, the same fractional release rate was assumed, but in this case it was presumed to occur when the Ra inventory was projected to reach a maximum at more than 10 y after repository closure. The estimated concentrations and doses were, in turn, compared to the concentration limit, specified in the Ground Water Protection Standards (GWPSs) in the case of Ra, or derived, in the case of C, on the basis of the regulatory dose rate limit. Due to the small inventory of C in the waste, and its short half-life relative to the performance period evaluated, its estimated concentration in the ground water would be slightly more than 4% of the derived GWPS. Due to the relatively small initial inventory of Th, the precursor of Ra, and the correspondingly small quantities of higher atomic number actinides that could, through decay, produce additional quantities of Th, its estimated concentration in the ground water would be less than 3% of the GWPS, leaving the remaining portion of the limit for potential contributions from Ra. At the same time, however, it must be recognized that, in this case, the regulations require that any contributions of naturally

  11. The disposal of nuclear waste in space

    NASA Technical Reports Server (NTRS)

    Burns, R. E.

    1978-01-01

    The important problem of disposal of nuclear waste in space is addressed. A prior study proposed carrying only actinide wastes to space, but the present study assumes that all actinides and all fission products are to be carried to space. It is shown that nuclear waste in the calcine (oxide) form can be packaged in a container designed to provide thermal control, radiation shielding, mechanical containment, and an abort reentry thermal protection system. This package can be transported to orbit via the Space Shuttle. A second Space Shuttle delivers an oxygen-hydrogen orbit transfer vehicle to a rendezvous compatible orbit and the mated OTV and waste package are sent to the preferred destination. Preferred locations are either a lunar crater or a solar orbit. Shuttle traffic densities (which vary in time) are given and the safety of space disposal of wastes discussed.

  12. Systems engineering programs for geologic nuclear waste disposal

    SciTech Connect

    Klett, R. D.; Hertel, Jr., E. S.; Ellis, M. A.

    1980-06-01

    The design sequence and system programs presented begin with general approximate solutions that permit inexpensive analysis of a multitude of possible wastes, disposal media, and disposal process properties and configurations. It then continues through progressively more precise solutions as parts of the design become fixed, and ends with repository and waste form optimization studies. The programs cover both solid and gaseous waste forms. The analytical development, a program listing, a users guide, and examples are presented for each program. Sensitivity studies showing the effects of disposal media and waste form thermophysical properties and repository layouts are presented as examples.

  13. Reversing nuclear opposition: evolving public acceptance of a permanent nuclear waste disposal facility.

    PubMed

    Jenkins-Smith, Hank C; Silva, Carol L; Nowlin, Matthew C; deLozier, Grant

    2011-04-01

    Nuclear facilities have long been seen as the top of the list of locally unwanted land uses (LULUs), with nuclear waste repositories generating the greatest opposition. Focusing on the case of the Waste Isolation Pilot Plant (WIPP) in southern New Mexico, we test competing hypotheses concerning the sources of opposition and support for siting the facility, including demographics, proximity, political ideology, and partisanship, and the unfolding policy process over time. This study tracks the changes of risk perception and acceptance of WIPP over a decade, using measures taken from 35 statewide surveys of New Mexico citizens spanning an 11-year period from fall 1990 to summer 2001. This time span includes periods before and after WIPP became operational. We find that acceptance of WIPP is greater among those whose residences are closest to the WIPP facility. Surprisingly, and contrary to expectations drawn from the broader literature, acceptance is also greater among those who live closest to the nuclear waste transportation route. We also find that ideology, partisanship, government approval, and broader environmental concerns influence support for WIPP acceptance. Finally, the sequence of procedural steps taken toward formal approval of WIPP by government agencies proved to be important to gaining public acceptance, the most significant being the opening of the WIPP facility itself.

  14. Experimental Simulation of the Radionuclide Behaviour in the Process of Creating Additional Safety Barriers in Solid Radioactive Waste Repositories Containing Irradiated Graphite

    NASA Astrophysics Data System (ADS)

    Pavliuk, A. O.; Kotlyarevskiy, S. G.; Bespala, E. V.; Zakarova, E. V.; Rodygina, N. I.; Ermolaev, V. M.; Proshin, I. M.; Volkova, A.

    2016-08-01

    Results of the experimental modeling of radionuclide behavior when creating additional safety barriers in solid radioactive waste repositories are presented. The experiments were run on the repository mockup containing solid radioactive waste fragments including irradiated graphite. The repository mockup layout is given; the processes with radionuclides that occur during the barrier creation with a clayey solution and during the following barrier operation are investigated. The results obtained confirm high anti-migration and anti-filtration properties of clay used for the barrier creation even under the long-term excessive water saturation of rocks confining the repository.

  15. Scientific Basis for Nuclear Waste Management

    NASA Astrophysics Data System (ADS)

    Trask, Newell J.

    As a result of the Reagan administration's commitment to nuclear energy as a significant future energy source and of attempts by the 97th Congress to grapple with legislative aspects of the problem, increased attention has focused recently on the problem of safely disposing of nuclear waste. These proceedings of the Third Symposium on Nuclear Waste Management of the Materials Research Society provide insight into the status of investigations on the subject as of late 1980. As with volumes 1 and 2 of this series, the 77 contributions are all short progress reports of ongoing research with the emphasis fittingly on materials science. Readers who wish extensive background material on the problems of nuclear-waste management and disposal, details of specific sites, or overviews of the programs of research in this country and abroad will have to look elsewhere.

  16. Repository environmental parameters and models/methodologies relevant to assessing the performance of high-level waste packages in basalt, tuff, and salt

    SciTech Connect

    Claiborne, H.C.; Croff, A.G.; Griess, J.C.; Smith, F.J.

    1987-09-01

    This document provides specifications for models/methodologies that could be employed in determining postclosure repository environmental parameters relevant to the performance of high-level waste packages for the Basalt Waste Isolation Project (BWIP) at Richland, Washington, the tuff at Yucca Mountain by the Nevada Test Site, and the bedded salt in Deaf Smith County, Texas. Guidance is provided on the identify of the relevant repository environmental parameters; the models/methodologies employed to determine the parameters, and the input data base for the models/methodologies. Supporting studies included are an analysis of potential waste package failure modes leading to identification of the relevant repository environmental parameters, an evaluation of the credible range of the repository environmental parameters, and a summary of the review of existing models/methodologies currently employed in determining repository environmental parameters relevant to waste package performance. 327 refs., 26 figs., 19 tabs.

  17. Site characterization plan: Yucca Mountain site, Nevada research and development area, Nevada: Consultation draft, Nuclear Waste Policy Act: Volume 2

    SciTech Connect

    1988-01-01

    The Yucca Mountain site in Nevada is one of three candidate sites for the first geologic repository for radioactive waste. On May 28, 1986, it was recommended for detailed study in a program of site characterization. This site characterization plan (SCP) has been prepared in accordance with the requirements of the Nuclear Waste Policy Act to summarize the information collected to date about the geologic conditions at the site; to describe the conceptual designs for the repository and the waste package and to present the plans for obtaining the geologic information necessary to demonstrate the suitability of the site for a repository, to design the repository and the waste package, to prepare an environmental impact statement, and to obtain from the US Nuclear Regulatory Commission (NRC) an authorization to construct the repository. Chapter 3 summarizes present knowledge of the regional and site hydrologic systems. The purpose of the information presented is to (1) describe the hydrology based on available literature and preliminary site-exploration activities that have been or are being performed and (2) provide information to be used to develop the hydrologic aspects of the planned site characterization program. Chapter 4 contains geochemical information about the Yucca Mountain site. The chapter references plan for continued collection of geochemical data as a part of the site characterization program. Chapter 4 describes and evaluates data on the existing climate and site meterology, and outlines the suggested procedures to be used in developing and validating methods to predict future climatic variation. 534 refs., 100 figs., 72 tabs.

  18. Using Single-Camera 3-D Imaging to Guide Material Handling Robots in a Nuclear Waste Package Closure System

    SciTech Connect

    Rodney M. Shurtliff

    2005-09-01

    Nuclear reactors for generating energy and conducting research have been in operation for more than 50 years, and spent nuclear fuel and associated high-level waste have accumulated in temporary storage. Preparing this spent fuel and nuclear waste for safe and permanent storage in a geological repository involves developing a robotic packaging system—a system that can accommodate waste packages of various sizes and high levels of nuclear radiation. During repository operation, commercial and government-owned spent nuclear fuel and high-level waste will be loaded into casks and shipped to the repository, where these materials will be transferred from the casks into a waste package, sealed, and placed into an underground facility. The waste packages range from 12 to 20 feet in height and four and a half to seven feet in diameter. Closure operations include sealing the waste package and all its associated functions, such as welding lids onto the container, filling the inner container with an inert gas, performing nondestructive examinations on welds, and conducting stress mitigation. The Idaho National Laboratory is designing and constructing a prototype Waste Package Closure System (WPCS). Control of the automated material handling is an important part of the overall design. Waste package lids, welding equipment, and other tools must be moved in and around the closure cell during the closure process. These objects are typically moved from tool racks to a specific position on the waste package to perform a specific function. Periodically, these objects are moved from a tool rack or the waste package to the adjacent glovebox for repair or maintenance. Locating and attaching to these objects with the remote handling system, a gantry robot, in a loosely fixtured environment is necessary for the operation of the closure cell. Reliably directing the remote handling system to pick and place the closure cell equipment within the cell is the major challenge.

  19. ACCOUNTING FOR A VITRIFIED PLUTONIUM WASTE FORM IN THE YUCCA MOUNTAIN REPOSITORY TOTAL SYSTEM PERFORMANCE ASSESSMENT (TSPA)

    SciTech Connect

    Marra, J

    2007-02-12

    A vitrification technology utilizing a lanthanide borosilicate (LaBS) glass appears to be a viable option for dispositioning excess weapons-useable plutonium that is not suitable for processing into mixed oxide (MOX) fuel. A significant effort to develop a glass formulation and vitrification process to immobilize plutonium was completed in the mid-1990s to support the Plutonium Immobilization Program (PIP). Further refinement of the vitrification process was accomplished as part of the Am/Cm solution vitrification project. The LaBS glass formulation was found to be capable of immobilizing in excess of 10 wt% Pu and to be very tolerant of the impurities accompanying the plutonium material streams. Thus, this waste form would be suitable for dispositioning plutonium owned by the Department of Energy-Office of Environmental Management (DOE-EM) that may not be well characterized and may contain high levels of impurities. The can-in-canister technology demonstrated in the PIP could be utilized to dispose of the vitrified plutonium in the federal radioactive waste repository. The can-in-canister technology involves placing small cans of the immobilized Pu form into a high level waste (HLW) glass canister fitted with a rack to hold the cans and then filling the canister with HLW glass. Testing was completed to demonstrate that this technology could be successfully employed with little or no impact to current Defense Waste Processing Facility (DWPF) operation and that the resulting canisters were essentially equivalent to the present HLW glass canisters to be dispositioned in the federal repository. The performance of wastes in the repository and, moreover, the performance of the entire repository system is being evaluated by the Department of Energy-Office of Civilian Radioactive Waste Management (DOE-RW) using a Total System Performance Assessment (TSPA) methodology. Technical bases documents (e.g., Analysis/Modeling Reports (AMR)) that address specific issues regarding

  20. Nuclear energy and radioactive waste disposal in the age of recycling

    SciTech Connect

    Conca, James L.; Apted, Michael

    2007-07-01

    The magnitude of humanity's energy needs requires that we embrace a multitude of various energy sources and applications. For a variety of reasons, nuclear energy must be a major portion of the distribution, at least one third. The often-cited strategic hurdle to this approach is nuclear waste disposal. Present strategies concerning disposal of nuclear waste need to be changed if the world is to achieve both a sustainable energy distribution by 2040 and solve the largest environmental issue of the 21. century - global warming. It is hoped that ambitious proposals to replace fossil fuel power generation by alternatives will drop the percentage of fossil fuel use substantially, but the absolute amount of fossil fuel produced electricity must be kept at or below its present 10 trillion kW-hrs/year. Unfortunately, the rapid growth in consumption to over 30 trillion kW-hrs/year by 2040, means that 20 trillion kW-hrs/yr of non-fossil fuel generated power has to come from other sources. If half of that comes from alternative non-nuclear, non-hydroelectric sources (an increase of 3000%), then nuclear still needs to increase by a factor of four worldwide to compensate. Many of the reasons nuclear energy did not expand after 1970 in North America (proliferation, capital costs, operational risks, waste disposal, and public fear) are no longer a problem. The WIPP site in New Mexico, an example of a solution to the nuclear waste disposal issue, and also to public fear, is an operating deep geologic nuclear waste repository in the massive bedded salt of the Salado Formation. WIPP has been operating for eight years, and as of this writing, has disposed of over 50,000 m{sup 3} of transuranic waste (>100 nCi/g but <23 Curie/liter) including high activity waste. The Salado Formation is an ideal host for any type of nuclear waste, especially waste from recycled spent fuel. (authors)

  1. Vermont's involvement with the DOE's high-level radioactive waste disposal crystalline repository project. Final technical report, January 1-September 30, 1986

    SciTech Connect

    1986-09-01

    The US Department of Energy (DOE) is charged with siting a second repository for the disposal of highly radioactive nuclear wastes. Because of this siting process, the DOE has looked to localities in 17 states in the eastern US for possible sites in crystalline rock. During the beginning of the progress report period, crystalline rocks in Vermont were under consideration as sites for further study. Vermont, through the Vermont State Geologist's Office, was closely involved with the DOE program during this period. Our main function has been to review DOE reports; attend DOE workshops and meetings; and inform the Vermont public, with the help of the DOE, about the high-level nuclear waste repository siting process. Nine sites in Vermont were under consideration during the Regional Characterization Phase until January 16, 1986. Because of this fact, there was considerable public interest in this program. Upon release of the Draft Area Recommendation Report, Vermont crystalline rock bodies were dropped from consideration. A site in New Hampshire and two sites in Maine remained on the list. Because of the draft status of the report and the possibility that a site 20 miles from the Vermont border in New Hampshire could remain as a selected site, Vermont has stayed active and interested. Two briefings and hearings were held in the State during the comment period January 16 through April 16, 1986. A thorough review of the Draft Area Recommendation Report was completed using reviewers from our Office, State agencies, outside experts, and citizen groups. With the announcement on May 28, 1986 of the suspension of the second repository siting process in crystalline rocks, our Office has worked toward closing out our active involvement.

  2. [Distribution and activity of microorganisms in the deep repository for liquid radioactive waste at the Siberian Chemical Combine].

    PubMed

    Nazina, T N; Luk'ianova, E A; Zakharova, E V; Ivoĭlov, V S; Poltaraus, A B; Kalmykov, S N; Beliaev, S S; Zubkov, A A

    2006-01-01

    The physicochemical conditions, composition of microbial communities, and the rates of anaerobic processes in the deep sandy horizons used as a repository for liquid radioactive wastes (LRW) at the Siberian Chemical Combine (Seversk, Tomsk oblast), were studied. Formation waters from the observation wells drilled into the production horizons of the radioactive waste disposal site were found to be inhabited by microorganisms of different physiological groups, including aerobic organotrophs, anaerobic fermentative, denitrifying, sulfate-reducing, and methanogenic bacteria. The density of microbial population, as determined by cultural methods, was low and usually did not exceed 10(4) cells/ml. Enrichment cultures of microorganisms producing gases (hydrogen, methane, carbon dioxide, and hydrogen sulfide) and capable of participation in the precipitation of metal sulfides were obtained from the waters of production horizons. The contemporary processes of sulfate reduction and methanogenesis were assayed; the rates of these terminal processes of organic matter destruction were found to be low. The denitrifying bacteria from the underground repository were capable of reducing the nitrates contained in the wastes, provided sources of energy and biogenic elements were available. Biosorption of radionuclides by the biomass of aerobic bacteria isolated from groundwater was demonstrated. The results obtained give us insight into the functional structure of the microbial community inhabiting the waters of repository production horizons. This study indicates that the numbers and activity of microbial cells are low both inside and outside the zone of radioactive waste dispersion, in spite of the long period of waste discharge.

  3. [Distribution and activity of microorganisms in the deep repository for liquid radioactive waste at the Siberian Chemical Combine].

    PubMed

    Nazina, T N; Luk'ianova, E A; Zakharova, E V; Ivoĭlov, V S; Poltaraus, A B; Kalmykov, S N; Beliaev, S S; Zubkov, A A

    2006-01-01

    The physicochemical conditions, composition of microbial communities, and the rates of anaerobic processes in the deep sandy horizons used as a repository for liquid radioactive wastes (LRW) at the Siberian Chemical Combine (Seversk, Tomsk oblast), were studied. Formation waters from the observation wells drilled into the production horizons of the radioactive waste disposal site were found to be inhabited by microorganisms of different physiological groups, including aerobic organotrophs, anaerobic fermentative, denitrifying, sulfate-reducing, and methanogenic bacteria. The density of microbial population, as determined by cultural methods, was low and usually did not exceed 10(4) cells/ml. Enrichment cultures of microorganisms producing gases (hydrogen, methane, carbon dioxide, and hydrogen sulfide) and capable of participation in the precipitation of metal sulfides were obtained from the waters of production horizons. The contemporary processes of sulfate reduction and methanogenesis were assayed; the rates of these terminal processes of organic matter destruction were found to be low. The denitrifying bacteria from the underground repository were capable of reducing the nitrates contained in the wastes, provided sources of energy and biogenic elements were available. Biosorption of radionuclides by the biomass of aerobic bacteria isolated from groundwater was demonstrated. The results obtained give us insight into the functional structure of the microbial community inhabiting the waters of repository production horizons. This study indicates that the numbers and activity of microbial cells are low both inside and outside the zone of radioactive waste dispersion, in spite of the long period of waste discharge. PMID:17205810

  4. Icelandic basaltic geothermal field: A natural analog for nuclear waste isolation in basalt

    SciTech Connect

    Ulmer, G.C.; Grandstaff, D.E. . Dept. of Geology)

    1984-11-21

    Analog studies of Icelandic geothermal fields have shown that the design of nuclear waste repositories in basalt can benefit by comparison to the data base already available from the development of these geothermal fields. A high degree of similarity exists between these two systems: their petrology, groundwater geochemistry, mineral solubilities, hydrologic parameters, temperature ranges, water-rock redox equilibria, hydrothermal pH values, and secondary mineralogies all show considerable overlap in the range of values. The experimentally-simulated hydrothermal studies of the basaltic nuclear waste repository rocks have, at this time, produced a data base that receives a strong confirmation from the Icelandic analog. Furthermore, the Icelandic analog should eventually be employed to extrapolate into higher and lower temperatures, into longer time-base chemical comparisons, and into more realistic mineral deposition studies, than have been possible in the laboratory evaluations of the nuclear waste repository designs. This eventual use of the Icelandic analog will require cooperative work with the Icelandic Geological Survey. 46 refs., 4 figs., 2 tabs.

  5. Conditions inside Water Pooled in a Failed Nuclear Waste Container and its Effect on Radionuclide Release

    NASA Astrophysics Data System (ADS)

    Hamdan, L. K.; Walton, J. C.; Woocay, A.

    2009-12-01

    Nuclear power use is expected to expand in the future, as part of the global clean energy initiative, to meet the world’s surging energy demand, and attenuate greenhouse gas emissions, which are mainly caused by fossil fuels. As a result, it is estimated that hundreds of thousands of metric tons of spent nuclear fuel (SNF) will accumulate. SNF disposal has major environmental (radiation exposure) and security (nuclear proliferation) concerns. Storage in unsaturated zone geological repositories is a reasonable solution for dealing with SNF. One of the key factors that determine the performance of the geological repository is the release of radionuclides from the engineered barrier system. Over time, the nuclear waste containers are expected to fail gradually due to general and localized corrosions and eventually infiltrating water will have access to the nuclear waste. Once radionuclides are released, they will be transported by water, and make their way to the accessible environment. Physical and chemical disturbances in the environment over the container will lead to different corrosion rates, causing different times and locations of penetration. One possible scenario for waste packages failure is the bathtub model, where penetrations occur on the top of the waste package and water pools inside it. In this paper the bathtub-type failed waste container is considered. We shed some light on chemical and physical processes that take place in the pooled water inside a partially failed waste container (bathtub category), and the effects of these processes on radionuclide release. Our study considers two possibilities: temperature stratification of the pooled water versus mixing process. Our calculations show that temperature stratification of the pooled water is expected when the waste package is half (or less) filled with water. On the other hand, when the waste package is fully filled (or above half) there will be mixing in the upper part of water. The effect of

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

    SciTech Connect

    Apps, J.A.

    1987-01-01

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

  7. Illustration of sampling-based approaches to the calculation of expected dose in performance assessments for the proposed high level radioactive waste repository at Yucca Mountain, Nevada.

    SciTech Connect

    Helton, Jon Craig; Sallaberry, Cedric J. PhD.

    2007-04-01

    A deep geologic repository for high level radioactive waste is under development by the U.S. Department of Energy at Yucca Mountain (YM), Nevada. As mandated in the Energy Policy Act of 1992, the U.S. Environmental Protection Agency (EPA) has promulgated public health and safety standards (i.e., 40 CFR Part 197) for the YM repository, and the U.S. Nuclear Regulatory Commission has promulgated licensing standards (i.e., 10 CFR Parts 2, 19, 20, etc.) consistent with 40 CFR Part 197 that the DOE must establish are met in order for the YM repository to be licensed for operation. Important requirements in 40 CFR Part 197 and 10 CFR Parts 2, 19, 20, etc. relate to the determination of expected (i.e., mean) dose to a reasonably maximally exposed individual (RMEI) and the incorporation of uncertainty into this determination. This presentation describes and illustrates how general and typically nonquantitive statements in 40 CFR Part 197 and 10 CFR Parts 2, 19, 20, etc. can be given a formal mathematical structure that facilitates both the calculation of expected dose to the RMEI and the appropriate separation in this calculation of aleatory uncertainty (i.e., randomness in the properties of future occurrences such as igneous and seismic events) and epistemic uncertainty (i.e., lack of knowledge about quantities that are poorly known but assumed to have constant values in the calculation of expected dose to the RMEI).

  8. High Resolution 3d Imaging during the Construction of National Radioactive Waste Repository from BÁTAAPÁTI, Hungary

    NASA Astrophysics Data System (ADS)

    Gaich, A.; Deák, F.; Pötsch, M.

    2012-12-01

    The Hungarian National Radioactive Waste Repository is being built in the neighborhood of the village called Bátaapáti. The program of the new disposal facility for the low- and intermediate-level wastes (L/ILW) is conducted by PURAM (Public Limited Company for Radioactive Waste Management). The Bátaapáti underground research program began in February 2005, with the excavation of the two inclined exploratory tunnels. These tunnels have 30 m distance between their axes, 10% inclination and 1.7 km length, and have reached the 0 m Baltic sea-level in the Mórágy Granite Formation. The safety of nuclear repository mainly is influenced by the ground behaviour and its fracturing hence mapping of the geological features has a great importance. Because of the less stable ground, the cavern walls were shotcreted after every tunnelling advance. The site geologists were required to make the tunnel mapping after every drill and blast cycle. The time interval was short and the documenting work was unrepeatable due to the shotcrete supported walls, so it was very important to use a modern, precise system to create 3D photorealistic models of the rock surfaces on the excavated tunnel walls. We have chosen the photogrammetric method, because it has adequate resolution and quality for the photo combined 3D models. At the beginning, we had used the JointMetriX3D (JMX) system and subsequently ShapeMetriX3D (SMX) in the repository chamber excavation phase. From the acquired 3D images through geological mapping is performed as the system allows directly measuring geometric information on visible discontinuities such as dip and dip direction. Descriptive rock mass parameters such as spacing, area, roughness are instantly available. In this article we would like to continue that research having made by JMX model of a tunnel face of "TSZV" access tunnel and using SMX model of a tunnel face from "DEK" Chamber. Our studies were carried out by field engineering geologists on further

  9. Expected Behavior of Basaltic Magma with the Proposed High Level Nuclear Repository at Yucca Mountain, Nevada

    NASA Astrophysics Data System (ADS)

    Apted, M.; Morrissey, M.

    2007-12-01

    The expected series of eruptive events for a future igneous event in Yucca Mountain within the next 1 MY is comparable to that at Lathrop Wells basalt center and other Crater Flats Quaternary volcanoes. Lathrop Wells and Crater Flats Quaternary volcanoes are, in general, comprised of a single scoria cone with one or two lava flow fields extending from the base. The lava flow fields associated with scoria cones all appear to extend from the base of a scoria cone and to be comprised of lava terraces. A three-dimensional model of the plumbing system for a possible future igneous event is presented in this paper, based on the characteristic features of eruptive deposits at Lathrop Wells and other Crater Flats Quaternary volcanoes. Also described in the model are consequences related to the interaction between magma and the repository. The repository is expected to be 200-300 m below the surface and comprised of parallel drifts 5 m in diameter, 0.5-1.0 km in length and spaced 85 m. Each drift is to be filled with a series of 1.8 m diameter waste packages made of Alloy 22 stainless steel. The conceptual model of the plumbing system and related consequences are described in six stages. Stage 1 Intersection of dike with drift: One dike will intersect the repository. The width of a future dike in YMR is expected to vary along the length with a maximum value of < 4.0 m at repository depths. The number of drifts that will be intersected by the dike will be 6-24 depending on the lateral extent of the dike through the repository. Stage 2 Initial stage magma-drift interaction: The lateral variation in magma properties will produce, in general, two different styles of expected activity upon entering a drift: a mixture of gas and fragments of magma characteristic of a lava fountain at wide portions of the dike, and crystallizing magma relatively depleted in volatiles at the narrowest part of the dike. A spray of pyroclastics is expected inside a drift from a lava fountain that

  10. Bentonite Clay Evolution at Elevated Pressures and Temperatures: An experimental study for generic nuclear repositories

    NASA Astrophysics Data System (ADS)

    Caporuscio, F. A.; Cheshire, M.; McCarney, M.

    2012-12-01

    The Used Fuel Disposition Campaign is presently engaged in looking at various generic repository options for disposal of used fuel. Of interest are the disposal of high heat load canisters ,which may allow for a reduced repository footprint. The focus of this experimental work is to characterize Engineered Barrier Systems (EBS) conditions in repositories. Clay minerals - as backfill or buffer materials - are critical to the performance of the EBS. Experiments were performed in Dickson cells at 150 bar and sequentially stepped from 125 oC to 300 oC over a period of ~1 month. An unprocessed bentonite from Colony, Wyoming was used as the buffer material in each experiment. An K-Ca-Na-Cl-rich brine (replicating deep Stripa groundwater) was used at a 9:1 water:rock ratio. The baseline experiment contained brine + clay, while three other experiments contained metals that could be used as waste form canisters (brine +clay+304SS, brine+clay+316SS, brine+clay+Cu). All experiments were buffered at the Mt-Fe oxygen fugacity univarient line. As experiment temperature increased and time progressed, pH, K and Ca ion concentrations dropped, while Si, Na, and SO4 concentrations increased. Silicon was liberated into the fluid phase (>1000 ppm) and precipitated during the quenching of the experiment. The precipitated silica transformed to cristobalite as cooling progressed. Potassium was mobilized and exchanged with interlayer Na, transitioning the clay from Na-montmorillonite to K-smectite. Though illitization was not observed in these experiments, its formation may be kinetically limited and longer-term experiments are underway to evaluate the equilibrium point in this reaction. Clinoptilolite present in the starting bentonite mixture is unstable above 150 oC. Hence, the zeolite broke down at high temperatures but recrystallized as the quench event occurred. This was borne out in SEM images that showed clinoptilolite as a very late stage growth mineral. Both experimental runs

  11. Four themes that underlie the high-level nuclear waste management program

    SciTech Connect

    Sprecher, W.M.

    1989-01-01

    In 1982, after years of deliberation and in response to mounting pressures from environmental, industrial, and other groups, the US Congress enacted the Nuclear Waste Policy Act (NWPA) of 1982, which was signed into law by the President in January 1983. That legislation signified a major milestone in the nation's management of high-level nuclear waste, since it represented a consensus among the nation's lawmakers to tackle a problem that had evaded solution for decades. Implementation of the NWPA has proven to be exceedingly difficult, as attested by the discord generated by the US Department of Energy's (DOE's) geologic repository and monitored retrievable storage (MRS) facility siting activities. The vision that motivated the crafters of the 1982 act became blurred as opposition to the law increased. After many hearings that underscored the public's concern with the waste management program, the Congress enacted the Nuclear Waste Policy Amendments Act of 1987 (Amendments Act), which steamlined and focused the program, while establishing three independent bodies: the MRS Review Commission, the Nuclear Waste Technical Review Board, and the Office of the Nuclear Waste Negotiator. Yet, even as the program evolves, several themes characterizing the nation's effort to solve the waste management problem continue to prevail. The first of these themes has to do with social consciousness, and the others that follow deal with technical leadership, public involvement and risk perceptions, and program conservatism.

  12. Nuclear waste isolation activities report

    SciTech Connect

    1980-12-01

    Included are: a report from the Deputy Assistant Secretary, a summary of recent events, new literature, a list of upcoming waste management meetings, and background information on DOE`s radwaste management programs. (DLC)

  13. Analysis by simulation of the disposition of nuclear fuel waste

    SciTech Connect

    Turek, J.L.

    1980-09-01

    A descriptive simulation model is developed which includes all aspects of nuclear waste disposition. The model is comprised of two systems, the second system orchestrated by GASP IV. A spent fuel generation prediction module is interfaced with the AFR Program Management Information System and a repository scheduling information module. The user is permitted a wide range of options with which to tailor the simulation to any desired storage scenario. The model projects storage requirements through the year 2020. The outputs are evaluations of the impact that alternative decision policies and milestone date changes have on the demand for, the availability of, and the utilization of spent fuel storage capacities. Both graphs and detailed listings are available. These outputs give a comprehensive view of the particular scenario under observation, including the tracking, by year, of each discharge from every reactor. Included within the work is a review of the status of spent fuel disposition based on input data accurate as of August 1980. The results indicate that some temporary storage techniques (e.g., transshipment of fuel and/or additional at-reactor storage pools) must be utilized to prevent reactor shutdowns. These techniques will be required until the 1990's when several AFR facilities, and possibly one repository, can become operational.

  14. Science, Society, and America's Nuclear Waste: The Nuclear Waste Policy Act, Unit 3. Teacher Guide. Second Edition.

    ERIC Educational Resources Information Center

    Department of Energy, Washington, DC. Office of Civilian Radioactive Waste Management, Washington, DC.

    This guide is Unit 3 of the four-part series, Science, Society, and America's Nuclear Waste, produced by the U.S. Department of Energy's Office of Civilian Radioactive Waste Management. The goal of this unit is to identify the key elements of the United States' nuclear waste dilemma and introduce the Nuclear Waste Policy Act and the role of the…

  15. Stress-corrosion cracking of low-strength carbon steels in candidate high-level waste repository environments

    SciTech Connect

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

    1987-02-01

    A survey of the literature was performed to identify potential stress-corrosion cracking agents for low-strength carbon and low alloy steels in repository environments. It was found that a number of potent cracking agents are present, but stress-corrosion cracking is relatively unlikely in the bulk repository environments because of their low concentration. On the other hand, concentration of these species may occur by a number of mechanisms, and thus it is conceivable that the waste package could fail prematurely by stress corrosion. Accordingly, it is recommended that the lower concentration limits for potential cracking agents be identified under typical repository environments, in conjunction with modeling studies to assess the likelihood that the concentrating mechanisms will operate and to bound the upper limits of concentration for each mechanism. 82 refs.

  16. How to Shape a Successful Repository Program: Staged Development of Geologic Repositories for High-Level Waste

    SciTech Connect

    Isaacs, T.

    2004-10-03

    Programs to manage and ultimately dispose of high-level radioactive wastes are unique from scientific and technological as well as socio-political aspects. From a scientific and technological perspective, high-level radioactive wastes remain potentially hazardous for geological time periods--many millennia--and scientific and technological programs must be put in place that result in a system that provides high confidence that the wastes will be isolated from the accessible environment for these many thousands of years. Of course, ''proof'' in the classical sense is not possible at the outset, since the performance of the system can only be known with assurance, if ever, after the waste has been emplaced for those geological time periods. Adding to this challenge, many uncertainties exist in both the natural and engineered systems that are intended to isolate the wastes, and some of the uncertainties will remain regardless of the time and expense in attempting to characterize the system and assess its performance.

  17. Disposition of nuclear waste using subcritical accelerator-driven systems

    SciTech Connect

    Venneri, F.; Li, N.; Williamson, M.; Houts, M.; Lawrence, G.

    1998-12-31

    Spent fuel from nuclear power plants contains large quantities of Pu, other actinides, and fission products (FP). This creates challenges for permanent disposal because of the long half-lives of some isotopes and the potential for diversion of the fissile material. Two issues of concern for the US repository concept are: (1) long-term radiological risk peaking tens-of-thousands of years in the future; and (2) short-term thermal loading (decay heat) that limits capacity. An accelerator-driven neutron source can destroy actinides through fission, and can convert long-lived fission products to shorter-lived or stable isotopes. Studies over the past decade have established that accelerator transmutation of waste (ATW) can have a major beneficial impact on the nuclear waste problem. Specifically, the ATW concept the authors are evaluating: (1) destroys over 99.9% of the actinides; (2) destroys over 99.9% of the Tc and I; (3) separates Sr-90 and Cs-137; (4) separates uranium from the spent fuel; (5) produces electric power.

  18. Microstructural characterization of nuclear-waste ceramics

    SciTech Connect

    Ryerson, F.J.; Clarke, D.R.

    1982-09-22

    Characterization of nuclear waste ceramics requires techniques possessing high spatial and x-ray resolution. XRD, SEM, electron microprobe, TEM and analytical EM techniques are applied to ceramic formulations designed to immobilize both commercial and defense-related reactor wastes. These materials are used to address the strengths and limitations of the techniques above. An iterative approach combining all these techniques is suggested. 16 figures, 2 tables.

  19. Status of Proposed Repository for Latin-American Spent Fuel

    SciTech Connect

    Ferrada, J.J.

    2004-10-04

    This report compiles preliminary information that supports the premise that a repository is needed in Latin America and analyzes the nuclear situation (mainly in Argentina and Brazil) in terms of nuclear capabilities, inventories, and regional spent-fuel repositories. The report is based on several sources and summarizes (1) the nuclear capabilities in Latin America and establishes the framework for the need of a permanent repository, (2) the International Atomic Energy Agency (IAEA) approach for a regional spent-fuel repository and describes the support that international institutions are lending to this issue, (3) the current situation in Argentina in order to analyze the Argentinean willingness to find a location for a deep geological repository, and (4) the issues involved in selecting a location for the repository and identifies a potential location. This report then draws conclusions based on an analysis of this information. The focus of this report is mainly on spent fuel and does not elaborate on other radiological waste sources.

  20. The Economic, repository and proliferation implications of advanced nuclear fuel cycle

    SciTech Connect

    Deinert, Mark; Cady, K B

    2011-09-04

    The goal of this project was to compare the effects of recycling actinides using fast burner reactors, with recycle that would be done using inert matrix fuel burned in conventional light water reactors. In the fast reactor option, actinides from both spent light water and fast reactor fuel would be recycled. In the inert matrix fuel option, actinides from spent light water fuel would be recycled, but the spent inert matrix fuel would not be reprocessed. The comparison was done over a limited 100-year time horizon. The economic, repository and proliferation implications of these options all hinge on the composition of isotopic byproducts of power production. We took the perspective that back-end economics would be affected by the cost of spent fuel reprocessing (whether conventional uranium dioxide fuel, or fast reactor fuel), fuel manufacture, and ultimate disposal of high level waste in a Yucca Mountain like geological repository. Central to understanding these costs was determining the overall amount of reprocessing needed to implement a fast burner, or inert matrix fuel, recycle program. The total quantity of high level waste requiring geological disposal (along with its thermal output), and the cost of reprocessing were also analyzed. A major advantage of the inert matrix fuel option is that it could in principle be implemented using the existing fleet of commercial power reactors. A central finding of this project was that recycling actinides using an inert matrix fuel could achieve reductions in overall actinide production that are nearly very close to those that could be achieved by recycling the actinides using a fast burner reactor.