Science.gov

Sample records for nuclear waste repositories

  1. Informing future societies about nuclear waste repositories

    SciTech Connect

    Jensen, M.

    1994-04-01

    In 1990 a working group of the NKS (the Nordic nuclear safety program) was formed and give the task of established a basis for a common Nordic view of the need for information conservation for nuclear waste repositories. The Group investigated what tipy of information should be conserved; in what form the information should be kept; the quality of the information; and the problems of future retrieval of information, including retrieval after very long periods of time. Topics covered include the following: scientific aspects including social context of scientific solutions; information management; systems for conservation and retrieval of information including the problems of prediction; archives, markers, archives vs. markers, and continuing processes in society; Archive media including paper documents, microfilm, digital media, media lifetimes; and finally conclusions and recommendations.

  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. 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)

  5. 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.

  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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Nuclear waste repository research at the micro- to nanoscale

    SciTech Connect

    Schaefer, T.; Denecke, M. A.

    2010-04-06

    Micro- and nano-focused synchrotron radiation techniques to investigate determinant processes in contaminant transport in geological media are becoming especially an increasingly used tool in nuclear waste disposal research. There are a number of reasons for this but primarily they are driven by the need to characterize actinide speciation localized in components of heterogeneous natural systems. We summarize some of the recent research conducted by researchers of the Institute of Nuclear Waste Disposal (INE) at the Karlsruhe Institute of Technology using micro- and nano-focused X-ray beams for characterization of colloids and their interaction with minerals and of elemental and phase distributions in potential repository host rocks and actinide speciation in a repository natural analogues sample. Such investigations are prerequisite to ensuring reliable assessment of the long term radiological safety for proposed nuclear waste disposal sites.

  13. Nuclear waste repository transparency technology test bed demonstrations at WIPP

    SciTech Connect

    BETSILL,J. DAVID; ELKINS,NED Z.; WU,CHUAN-FU; MEWHINNEY,JAMES D.; AAMODT,PAUL

    2000-01-27

    Secretary of Energy, Bill Richardson, has stated that one of the nuclear waste legacy issues is ``The challenge of managing the fuel cycle's back end and assuring the safe use of nuclear power.'' Waste management (i.e., the back end) is a domestic and international issue that must be addressed. A key tool in gaining acceptance of nuclear waste repository technologies is transparency. Transparency provides information to outside parties for independent assessment of safety, security, and legitimate use of materials. Transparency is a combination of technologies and processes that apply to all elements of the development, operation, and closure of a repository system. A test bed for nuclear repository transparency technologies has been proposed to develop a broad-based set of concepts and strategies for transparency monitoring of nuclear materials at the back end of the fuel/weapons cycle. WIPP is the world's first complete geologic repository system for nuclear materials at the back end of the cycle. While it is understood that WIPP does not currently require this type of transparency, this repository has been proposed as realistic demonstration site to generate and test ideas, methods, and technologies about what transparency may entail at the back end of the nuclear materials cycle, and which could be applicable to other international repository developments. An integrated set of transparency demonstrations was developed and deployed during the summer, and fall of 1999 as a proof-of-concept of the repository transparency technology concept. These demonstrations also provided valuable experience and insight into the implementation of future transparency technology development and application. These demonstrations included: Container Monitoring Rocky Flats to WIPP; Underground Container Monitoring; Real-Time Radiation and Environmental Monitoring; Integrated level of confidence in the system and information provided. As the world's only operating deep geologic

  14. 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.

  15. 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

  16. 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.

  17. 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.

  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. Preliminary drift design analyses for nuclear waste repository in tuff

    SciTech Connect

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

    1990-01-30

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

  1. 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.

  2. 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.

  3. Migration of radionuclides through backfill in a nuclear waste repository

    SciTech Connect

    Lung, H.

    1986-01-01

    Four models are analyzed to predict the performance of a backfill layer as part of the waste package emplacement in a nuclear waste repository. The corresponding computer code for each model is also developed. The time-dependent mass transfer analysis on a spherical waste-backfill geometry indicates that the radioactive decay effect can enhance the mass transfer rate from the backfill instead of reducing it. The analysis yields the breakthrough time of the backfill layer, which in turn characterizes the backfill performance. A non-linear (Langmuir) sorption isotherm is used to describe the sorption saturation in the backfill. The steady state mass transport analysis through a prolate spheroidal waste-backfill geometry shows that a simple formula can be used to calculate the individual resistances to mass transport in backfill and in host rock. A general, non-recursive analytical solution is derived for a radioactive decay chain of arbitrary length in either a finite or a semi-infinite medium. Numerical examples are given for different boundary conditions and for different decay chains. The results justify that for a backfill layer made of low permeability material, a zero water velocity can be used in the backfill analysis. It is also shown that under normal repository conditions, the mass transfer rate from the backfill is quite small. For the daughter member with a smaller retardation coefficient than that of the mother nuclide, such as /sup 226/Ra in the /sup 234/U ..-->.. /sup 230/Th ..-->.. /sup 226/Ra chain, an interior maximum in the concentration profile appears in the backfill. This phenomenon can be seen only in a chain calculation.

  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. Annular air space effects on nuclear waste canister temperatures in a deep geologic waste repository

    SciTech Connect

    Lowry, W.E.; Cheung, H.; Davis, B.W.

    1980-05-13

    Air spaces in a deep geologic repository for nuclear high level waste will have an important effect on the long-term performance of the waste package. The important temperature effects of an annular air gap surrounding a high level waste canister are determined through 3-D numerical modeling. Air gap properties and parameters specifically analyzed and presented are the air gap size, surfaces emissivity, presence of a sleeve, and initial thermal power generation rate; particular emphasis was placed on determining the effect of these variables have on the canister surface temperature. Finally a discussion based on modeling results is presented which specifically relates the results to NRC regulatory considerations.

  7. Waste package performance evaluations for the proposed high-level nuclear waste repository at Yucca Mountain.

    PubMed

    Mon, Kevin G; Bullard, Bryan E; Mehta, Sunil; Lee, Joon H

    2004-04-01

    The evaluation studies of the proposed repository for long-term storage of spent nuclear fuel and high-level nuclear waste at Yucca Mountain, Nevada, are underway. Fulfillment of the requirements for limiting dose to the public, which includes containment of the radioactive waste emplaced in the proposed repository and subsequent slow release of radionuclides from the Engineered Barrier System (EBS) into the geosphere, will rely on a robust waste container design, among other EBS components. Part of the evaluation process involves sensitivity studies aimed at elucidating which model parameters contribute most to the waste package and overlying drip shield degradation characteristics. The model parameters identified for this study include (1) general corrosion rate parameters and (2) stress corrosion cracking (SCC) parameters. Temperature dependence and parameter uncertainty are evaluated for the general corrosion rate model parameters while for the SCC model parameters, uncertainty treatment of stress intensity factor, crack initiation threshold, and manufacturing flaw orientations are evaluated. Based on these evaluations new uncertainty distributions are generated and recommended for future analyses. Also, early waste package failures due to improper heat treatment were added to the waste package degradation model. The results of these investigations indicate that the waste package failure profiles are governed by the manufacturing flaw orientation model parameters.

  8. Basalt nuclear-waste repository remote sensing using electromagnetic techniques

    SciTech Connect

    Daily, W.D.; Buettner, H.M.

    1984-01-01

    The electromagnetic permittivity and attenuation rate of basalt, from the Near Surface Test Facility of the Basalt Waste Isolation Project at Hanford, Washington, have been measured in the laboratory as a function of water content at frequencies from 25 MHz to 1000 MHz. Both the permittivity and the attenuation rate are strongly related to water content of basalt in this frequency range. Completely dehydrated, the rock has a frequency-independent relative permittivity of about 8 and attenuation rates (inverse skin depths) of 0.04 m/sup -1/ and 3.2 m/sup -1/ at 25 MHz and 1000 MHz, respectively. When completely saturated by tap water to 6% by volume, the relative permittivity ranges from 16.5 to 10.0 and the attenuation ranges from 0.3 m/sup -1/ to 5.5 m/sup -1/ between 25 MHz and 1000 MHz. The data indicate that high-frequency electromagnetic remote sensing techniques, such as those used in radar, cross-borehole tomography, and borehole logging, may be useful in characterizing proposed basalt repositories and monitoring established waste repositories. Electromagnetic methods are particularly suited to delineating water content of the rock and, when completely saturated, crack and pore porosity of the rock mass within a repository. 7 references, 3 figures.

  9. 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).

  10. 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

  11. 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.

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

    NASA Astrophysics Data System (ADS)

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

    1980-10-01

    Activities are described which 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. The reference repository conditions developed are intended to serve as a guide for: (1) scientists conducting material performance tests; (2) engineers preparing the design of repositories; (3) the technically conservative conditions to be used as a basis for DOE license applications; and (4) scientists and engineers developing waste forms.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Potential Biogenic Corrosion of Alloy 22, A Candidate Nuclear Waste Packaging Materials, Under Simulated Repository Conditions

    SciTech Connect

    Horn, J.M.; Martin, S.I.; Rivera, A.J.; Bedrossian, P.J.; Lian, T.

    2000-01-12

    The U.S. Department of Energy has been charged with assessing the suitability of a geologic nuclear waste repository at Yucca Mountain (YM), NV. Microorganisms, both those endogenous to the repository site and those introduced as a result of construction and operational activities, may contribute to the corrosion of metal nuclear waste packaging and thereby decrease their useful lifetime as barrier materials. Evaluation of potential Microbiological Influenced Corrosion (MIC) on candidate waste package materials was undertaken reactor systems incorporating the primary elements of the repository: YM rock (either non-sterile or presterilized), material coupons, and a continual feed of simulated YM groundwater. Periodically, both aqueous reactor efflux and material coupons were analyzed for chemical and surfacial characterization. Alloy 22 coupons exposed for a year at room temperature in reactors containing non-sterile YM rock demonstrated accretion of chromium oxide and silaceous scales, with what appear to be underlying areas of corrosion.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

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

    USGS Publications Warehouse

    Neuzil, Christopher E.

    2014-01-01

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

  5. 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.

  6. Alternative methods of salt disposal at the seven salt sites for a nuclear waste repository

    SciTech Connect

    Not Available

    1987-02-01

    This study discusses the various alternative salt management techniques for the disposal of excess mined salt at seven potentially acceptable nuclear waste repository sites: Deaf Smith and Swisher Counties, Texas; Richton and Cypress Creek Domes, Mississippi; Vacherie Dome, Louisiana; and Davis and Lavender Canyons, Utah. Because the repository development involves the underground excavation of corridors and waste emplacement rooms, in either bedded or domed salt formations, excess salt will be mined and must be disposed of offsite. The salt disposal alternatives examined for all the sites include commercial use, ocean disposal, deep well injection, landfill disposal, and underground mine disposal. These alternatives (and other site-specific disposal methods) are reviewed, using estimated amounts of excavated, backfilled, and excess salt. Methods of transporting the excess salt are discussed, along with possible impacts of each disposal method and potential regulatory requirements. A preferred method of disposal is recommended for each potentially acceptable repository site. 14 refs., 5 tabs.

  7. 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.

  8. 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.

  9. Scenario Analysis for the Safety Assessment of Nuclear Waste Repositories: A Critical Review.

    PubMed

    Tosoni, Edoardo; Salo, Ahti; Zio, Enrico

    2017-09-05

    A major challenge in scenario analysis for the safety assessment of nuclear waste repositories pertains to the comprehensiveness of the set of scenarios selected for assessing the safety of the repository. Motivated by this challenge, we discuss the aspects of scenario analysis relevant to comprehensiveness. Specifically, we note that (1) it is necessary to make it clear why scenarios usually focus on a restricted set of features, events, and processes; (2) there is not yet consensus on the interpretation of comprehensiveness for guiding the generation of scenarios; and (3) there is a need for sound approaches to the treatment of epistemic uncertainties. © 2017 Society for Risk Analysis.

  10. 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.

  11. 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.

  12. 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.

  13. Deep geological isolation of nuclear waste: numerical modeling of repository scale hydrology

    SciTech Connect

    Dettinger, M.D.

    1980-04-01

    The Scope of Work undertaken covers three main tasks, described as follows: (Task 1) CDM provided consulting services to the University on modeling aspects of the study having to do with transport processes involving the local groundwater system near the repository and the flow of fluids and vapors through the various porous media making up the repository system. (Task 2) CDM reviewed literature related to repository design, concentrating on effects of the repository geometry, location and other design factors on the flow of fluids within the repository boundaries, drainage from the repository structure, and the eventual transport of radionucldies away from the repository site. (Task 3) CDM, in a joint effort with LLL personnel, identified generic boundary and initial conditions, identified processes to be modeled, and recommended a modeling approach with suggestions for appropriate simplifications and approximations to the problem and identifiying important parameters necessary to model the processes. This report consists of two chapters and an appendix. The first chapter (Chapter III of the LLL report) presents a detailed description and discussion of the modeling approach developed in this project, its merits and weaknesses, and a brief review of the difficulties anticipated in implementing the approach. The second chapter (Chapter IV of the LLL report) presents a summary of a survey of researchers in the field of repository performance analysis and a discussion of that survey in light of the proposed modeling approach. The appendix is a review of the important physical processes involved in the potential hydrologic transport of radionuclides through, around and away from deep geologic nuclear waste repositories.

  14. 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.

  15. Radioactive waste isolation in salt: peer review of the Office of Nuclear Waste Isolation's report on Functional Design Criteria for a Repository for High-Level Radioactive Waste

    SciTech Connect

    Hambley, D.F.; Russell, J.E.; Busch, J.S.; Harrison, W.; Edgar, D.E.; Tisue, M.W.

    1984-08-01

    This report summarizes Argonne's review of the Office of Nuclear Waste Isolation's (ONWI's) draft report entitled Functional Design Criteria for High-Level Nuclear Waste Repository in Salt, dated January 23, 1984. Recommendations are given for improving the ONWI draft report.

  16. Implications of environmental program planning for siting a nuclear waste repository at Yucca Mountain, Nevada, USA

    NASA Astrophysics Data System (ADS)

    Malone, Charles R.

    1990-01-01

    The US Department of Energy (DOE) plans to conduct site characterization studies at Yucca Mountain, Nevada, to determine if the location is a suitable site for a nuclear waste repository. In lieu of traditional environmental review in accordance with the National Environmental Policy Act of 1969, the DOE is relying on an environmental assessment (EA) mandated by the Nuclear Waste Policy Act of 1982 as the cornerstone of its environmental program for the Yucca Mountain Project. Because of statutory restrictions, the EA is not based on comprehensive baseline information. Neither does it address fundamentals of environmental analysis such as ecological integrity and assessment of cumulative impacts. Consequently, the present environmental program for Yucca Mountain reflects decisions made without complete information and integrated environmental review. The shortcomings of the program risk compromising the natural integrity of Yucca Mountain and invalidating future assessment of the ability of a nuclear waste repository located at the site to protect the environment. Significant improvements are needed in the repository siting program before it can serve as a model of how society can evaluate the long-term environmental consequences of advanced technologies, as has been suggested.

  17. Assessing the performance of geologic repositories for nuclear waste

    SciTech Connect

    Pigford, T.H.

    1984-08-01

    Predictions of the rate of release of radionuclides from waste packages, their rates of dissolution in groundwater, their hydrogeologic transport to the environment, and their ultimate uptake by people are summarized. Both the details of performance assessment and conclusions on performance are affected by what performance criteria are adopted. 9 references, 1 figure, 1 table.

  18. Albedo Neutron Dosimetry in a Deep Geological Disposal Repository for High-Level Nuclear Waste.

    PubMed

    Pang, Bo; Becker, Frank

    2016-06-24

    Albedo neutron dosemeter is the German official personal neutron dosemeter in mixed radiation fields where neutrons contribute to personal dose. In deep geological repositories for high-level nuclear waste, where neutrons can dominate the radiation field, it is of interest to investigate the performance of albedo neutron dosemeter in such facilities. In this study, the deep geological repository is represented by a shielding cask loaded with spent nuclear fuel placed inside a rock salt emplacement drift. Due to the backscattering of neutrons in the drift, issues concerning calibration of the dosemeter arise. Field-specific calibration of the albedo neutron dosemeter was hence performed with Monte Carlo simulations. In order to assess the applicability of the albedo neutron dosemeter in a deep geological repository over a long time scale, spent nuclear fuel with different ages of 50, 100 and 500 years were investigated. It was found out, that the neutron radiation field in a deep geological repository can be assigned to the application area 'N1' of the albedo neutron dosemeter, which is typical in reactors and accelerators with heavy shielding.

  19. 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

  20. 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

  1. Performance Assessment of a Generic Repository in Bedded Salt for DOE-Managed Nuclear Waste

    NASA Astrophysics Data System (ADS)

    Stein, E. R.; Sevougian, S. D.; Hammond, G. E.; Frederick, J. M.; Mariner, P. E.

    2016-12-01

    A mined repository in salt is one of the concepts under consideration for disposal of DOE-managed defense-related spent nuclear fuel (SNF) and high level waste (HLW). Bedded salt is a favorable medium for disposal of nuclear waste due to its low permeability, high thermal conductivity, and ability to self-heal. Sandia's Generic Disposal System Analysis framework is used to assess the ability of a generic repository in bedded salt to isolate radionuclides from the biosphere. The performance assessment considers multiple waste types of varying thermal load and radionuclide inventory, the engineered barrier system comprising the waste packages, backfill, and emplacement drifts, and the natural barrier system formed by a bedded salt deposit and the overlying sedimentary sequence (including an aquifer). The model simulates disposal of nearly the entire inventory of DOE-managed, defense-related SNF (excluding Naval SNF) and HLW in a half-symmetry domain containing approximately 6 million grid cells. Grid refinement captures the detail of 25,200 individual waste packages in 180 disposal panels, associated access halls, and 4 shafts connecting the land surface to the repository. Equations describing coupled heat and fluid flow and reactive transport are solved numerically with PFLOTRAN, a massively parallel flow and transport code. Simulated processes include heat conduction and convection, waste package failure, waste form dissolution, radioactive decay and ingrowth, sorption, solubility limits, advection, dispersion, and diffusion. Simulations are run to 1 million years, and radionuclide concentrations are observed within an aquifer at a point approximately 4 kilometers downgradient of the repository. The software package DAKOTA is used to sample likely ranges of input parameters including waste form dissolution rates and properties of engineered and natural materials in order to quantify uncertainty in predicted concentrations and sensitivity to input parameters. Sandia

  2. Malaysian alternative to international reference bentonite buffer in underground nuclear waste repository

    NASA Astrophysics Data System (ADS)

    Tadza, Mohd Yuhyi Mohd; Azmi, Nor Syafiqah Mohd; Mustapha, Roslanzairi; Desa, Nor Dalilah; Samuding, Kamarudin

    2017-01-01

    The performance of bentonite as buffer material in underground nuclear waste repository has been extensively being investigated all over the world. Over the years, almost exclusively, naturally occurring Wyoming sodium based bentonite (MX80) was tested as a reference buffer material. Other alternatives such as calcium and mixed based bentonites from all over the world were also examined for this specific application in respective countries. In Malaysia, the potential of naturally occurring bentonites have not clearly documented and may be considered for the application of buffer material in underground nuclear waste repository. In the context of underground radioactive waste storage, bentonite from Sabah volcanic formation, namely Andrassy bentonite was characterized in the laboratory and compared with MX80 and Deponit Ca-N bentonites. The geotechnical properties such as Atterberg limits, particle size distribution, specific gravity, cation exchange capacity, specific surface area and swelling potential were carefully determined. In addition, the water retention characteristics were established using a chilled-mirror dew-point potentiometer. Test results indicated that the Andrassy bentonite may be selected as the key component in the country's future development of deep underground radioactive waste facilities.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. Costs and impacts of transporting nuclear waste to candidate repository sites

    SciTech Connect

    McSweeney, T.I.; Peterson, R.W.; Gupta, R.

    1983-12-31

    In this paper, a status report on the current estimated costs and impacts of transporting high-level nuclear wastes to candidate disposal sites is given. Impacts in this analysis are measured in terms of risk to public health and safety. Since it is difficult to project the status of the nuclear industry to the time of repository operation - 20 to 50 years in the future - particular emphasis in the paper is placed on the evaluation of uncertainties. The first part of this paper briefly describes the characteristics of the waste that must be transported to a high-level waste disposal site. This discussion is followed by a section describing the characteristics of the waste transport system. Subsequent sections describe the costs and risk assessments of waste transport. Finally, in a concluding section, the effect of the uncertainties in the definition of the waste disposal system on cost and risk levels is evaluated. This last section also provides some perspectives on the magnitude of the cost and risk levels relative to other comparable costs and risks generally encountered. 13 references, 2 figures, 16 tables.

  9. 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.

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

    SciTech Connect

    Koudelka, Tomáš; Kruis, Jaroslav

    2016-06-08

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

  11. 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.

  12. 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.

  13. Development of permeable reactive barriers to prevent radionuclide migration from the nuclear waste repositories

    SciTech Connect

    Zakharova, E.; Kalmykov, S.; Batuk, O.; Kazakovskaya, T.; Shapovalov, V.; Haire, M.J.

    2007-07-01

    This paper is focused on three possible materials for permeable reactive barriers (PRB): 1) depleted uranium oxide that is accumulated as a residual product of the natural uranium enrichment process, 2) zero-valent iron and, 3) the composite material based on montmorillonite clay modified with different anion exchangers. The main aim of permeable reactive barriers is to prevent release of radionuclides emerging from a repository waste package containing spent nuclear fuel to outside the control area of the nuclear waste repository sites. The most experimentally developed material is depleted uranium oxide. It can be used both as a component of radiation shielding and as an absorbent for migrating long-lived radionuclides (especially {sup 237}Np and {sup 99}Tc). Experiments demonstrate the high sorption properties of depleted uranium oxide towards Np and Tc both from deionized water and from solution that simulates Yucca Mountain. Zero-valent iron, and the composite based on montmorillonite clay, also seem to be very promising to use in a PRB. Nano-particles of zero-valent iron with high surface will reduce high valency Np and Tc to the tetravalent state and thus immobilize them due to the extremely low solubility of corresponding hydroxides. The composite based on montmorillonite clay modified with different anion exchangers will possess high sorption affinity towards anionic and cationic species. (authors)

  14. Nuclear Waste Facing the Test of Time: The Case of the French Deep Geological Repository Project.

    PubMed

    Poirot-Delpech, Sophie; Raineau, Laurence

    2016-12-01

    The purpose of this article is to consider the socio-anthropological issues raised by the deep geological repository project for high-level, long-lived nuclear waste. It is based on fieldwork at a candidate site for a deep storage project in eastern France, where an underground laboratory has been studying the feasibility of the project since 1999. A project of this nature, based on the possibility of very long containment (hundreds of thousands of years, if not longer), involves a singular form of time. By linking project performance to geology's very long timescale, the project attempts "jump" in time, focusing on a far distant future, without understanding it in terms of generations. But these future generations remain measurements of time on the surface, where the issue of remembering or forgetting the repository comes to the fore. The nuclear waste geological storage project raises questions that neither politicians nor scientists, nor civil society, have ever confronted before. This project attempts to address a problem that exists on a very long timescale, which involves our responsibility toward generations in the far future.

  15. 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.

  16. 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).

  17. 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.

  18. Thermodynamic coupling of heat and matter flows in near-field regions of nuclear waste repositories

    SciTech Connect

    Carnahan, C.L.

    1983-11-01

    In near-field regions of nuclear waste repositories, thermodynamically coupled flows of heat and matter can occur in addition to the independent flows in the presence of gradients of temperature, hydraulic potential, and composition. The following coupled effects can occur: thermal osmosis, thermal diffusion, chemical osmosis, thermal filtration, diffusion thermal effect, ultrafiltration, and coupled diffusion. Flows of heat and matter associated with these effects can modify the flows predictable from the direct effects, which are expressed by Fourier's law, Darcy's law, and Fick's law. The coupled effects can be treated quantitatively together with the direct effects by the methods of the thermodynamics of irreversible processes. The extent of departure of fully coupled flows from predictions based only on consideration of direct effects depends on the strengths of the gradients driving flows, and may be significant at early times in backfills and in near-field geologic environments of repositories. Approximate calculations using data from the literature and reasonable assumptions of repository conditions indicate that thermal-osmotic and chemical-osmotic flows of water in semipermeable backfills may exceed Darcian flows by two to three orders of magnitude, while flows of solutes may be reduced greatly by ultrafiltration and chemical osmosis, relative to the flows predicted by advection and diffusion alone. In permeable materials, thermal diffusion may contribute to solute flows to a smaller, but still significant, extent.

  19. Functions of an engineered barrier system for a nuclear waste repository in basalt

    SciTech Connect

    Coons, W.E.; Moore, E.L.; Smith, M.J.; Kaser, J.D.

    1980-01-01

    Defined in this document are the functions of components selected for an engineered barrier system for a nuclear waste repository in basalt. The definitions provide a focal point for barrier material research and development by delineating the purpose and operative lifetime of each component of the engineered system. A five-component system (comprised of waste form, canister, buffer, overpack, and tailored backfill) is discussed in terms of effective operation throughout the course of repository history, recognizing that the emplacement environment changes with time. While components of the system are mutually supporting, redundancy is provided by subsystems of physical and chemical barriers which act in concert with the geology to provide a formidable barrier to transport of hazardous materials to the biosphere. The operating philosophy of the conceptual engineered barrier system is clarified by examples pertinent to storage in basalt, and a technical approach to barrier design and material selection is proposed. A method for system validation and qualification is also included which considers performance criteria proposed by external agencies in conjunction with site-specific models and risk assessment to define acceptable levels of system performance.

  20. 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)

  1. 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.

  2. Application of integral methods to prediction of heat transfer from a nuclear waste repository

    SciTech Connect

    Blesch, C J; Kulacki, F A; Christensen, R N

    1983-10-01

    Integral methods have been developed and applied to the prediction of the far field thermal impact of a nuclear waste repository. Specifically, the heat balance integral has been applied to a semi-infinite layered domain in which a limited number of sublayers form the repository overburden, and the repository is represented by an infinite plane beneath either one or two sublayers. Calculations for PWR spent fuel with an initial areal thermal loading of 60 kW/acre are carried out for various stratigraphies and overburden compositions. Results of the analyses are temperature distributions and heat fluxes to the surface as a function to time. Based on this study, the thermophysical properties of the individual layers are identified as the most important influence on temperature distributions and maximum temperature rise at any position above the repository. The thicknesses of the sublayers play a secondary role for a given rock composition. Where a comparison to exact or numerical solutions is possible, the method predicts maximum temperature increases in the overburden to within 10 percent. Heat fluxes to the surface are found to be relatively insensitive to overburden composition. For dome salt, a maximum of 1.2 percent to 2.7 percent of the initial areal thermal power of a five-term source reaches the surface. For bedded salt, a maximum of 1 percent to 1.8 percent of the initial areal thermal power reaches the surface over a wide range of sublayer compositions. Similarly, low percentages of initial areal thermal power reach the surface for the other stratigraphies considered in the calculations.

  3. 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)

  4. 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.

  5. 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.

  6. Performance assessments of nuclear waste repositories--A dialogue on their value and limitations

    USGS Publications Warehouse

    Ewing, Rodney C.; Tierney, Martin S.; Konikowe, Leonard F.; Rechard, Rob P.

    1999-01-01

    Performance Assessment (PA) is the use of mathematical models to simulate the long-term behavior of engineered and geologic barriers in a nuclear waste repository; methods of uncertainty analysis are used to assess effects of parametric and conceptual uncertainties associated with the model system upon the uncertainty in outcomes of the simulation. PA is required by the U.S. Environmental Protection Agency as part of its certification process for geologic repositories for nuclear waste. This paper is a dialogue to explore the value and limitations of PA. Two “skeptics” acknowledge the utility of PA in organizing the scientific investigations that are necessary for confident siting and licensing of a repository; however, they maintain that the PA process, at least as it is currently implemented, is an essentially unscientific process with shortcomings that may provide results of limited use in evaluating actual effects on public health and safety. Conceptual uncertainties in a PA analysis can be so great that results can be confidently applied only over short time ranges, the antithesis of the purpose behind long-term, geologic disposal. Two “proponents” of PA agree that performance assessment is unscientific, but only in the sense that PA is an engineering analysis that uses existing scientific knowledge to support public policy decisions, rather than an investigation intended to increase fundamental knowledge of nature; PA has different goals and constraints than a typical scientific study. The “proponents” describe an ideal, sixstep process for conducting generalized PA, here called probabilistic systems analysis (PSA); they note that virtually all scientific content of a PA is introduced during the model-building steps of a PSA, they contend that a PA based on simple but scientifically acceptable mathematical models can provide useful and objective input to regulatory decision makers. The value of the results of any PA must lie between these two

  7. 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

  8. 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.

  9. 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.

  10. 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).

  11. 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

  12. The new Wallula CO2 project may revive the old Columbia River Basalt (western USA) nuclear-waste repository project

    NASA Astrophysics Data System (ADS)

    Schwartz, Michael O.

    2017-07-01

    A novel CO2 sequestration project at Wallula, Washington, USA, makes ample use of the geoscientific data collection of the old nuclear waste repository project at the Hanford Site nearby. Both projects target the Columbia River Basalt (CRB). The new publicity for the old project comes at a time when the approach to high-level nuclear waste disposal has undergone fundamental changes. The emphasis now is on a technical barrier that is chemically compatible with the host rock. In the ideal case, the waste container is in thermodynamic equilibrium with the host-rock groundwater regime. The CRB groundwater has what it takes to represent the ideal case.

  13. 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.

  14. The Microbiology of Subsurface, Salt-Based Nuclear Waste Repositories: Using Microbial Ecology, Bioenergetics, and Projected Conditions to Help Predict Microbial Effects on Repository Performance

    SciTech Connect

    Swanson, Juliet S.; Cherkouk, Andrea; Arnold, Thuro; Meleshyn, Artur; Reed, Donald T.

    2016-11-17

    This report summarizes the potential role of microorganisms in salt-based nuclear waste repositories using available information on the microbial ecology of hypersaline environments, the bioenergetics of survival under high ionic strength conditions, and “repository microbiology” related studies. In areas where microbial activity is in question, there may be a need to shift the research focus toward feasibility studies rather than studies that generate actual input for performance assessments. In areas where activity is not necessary to affect performance (e.g., biocolloid transport), repository-relevant data should be generated. Both approaches will lend a realistic perspective to a safety case/performance scenario that will most likely underscore the conservative value of that case.

  15. 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.

  16. Geotechnical support and topical studies for nuclear waste geologic repositories: Annual report, Fiscal Year 1986

    SciTech Connect

    Not Available

    1986-11-01

    The multidisciplinary project was initiated in fiscal year 1986. It comprises two major interrelated parts: (1) Technical Assistance. This part of the project includes: (a) review of the progress of major projects in the DOE Office of Civilian Radioactive Waste Management Program and advise the Engineering and Geotechnology Division on significant technical issues facing each project; (b) analyze geotechnical data, reports, tests, surveys and plans for the different projects; (c) review and comment on major technical reports and other program documents such as site characterization plans and area characterization plans and (d) provide scientific and technical input at technical meetings. (2) Topical Studies. This activity comprises studies on scientific and technical topics, and issues of significance to in-situ testing, test analysis methods, and performance assessment of nuclear waste geologic repositories. The subjects of study were selected based on discussions with DOE staff. For fiscal year 1986, one minor and one major area of investigation were undertaken. The minor topic is a preliminary consideration and planning exercise for post-closure monitoring studies. The major topic, with subtasks involving various geoscience disciplines, is on the mechanical, hydraulic, geophysical and geochemical properties of fractures in geologic rock masses. The present report lists the technical reviews and comments made during the fiscal year and summarizes the technical progress of the topical studies.

  17. 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.

  18. Crevice Corrosion Behavior of Candidate Nuclear Waste Container Materials in Repository Environment

    SciTech Connect

    F. Hua; J. Sarver; W. Mohn

    2001-11-08

    Alloy 22 (UNS N06022) and Ti Grade 7 (UNS R52400) have been proposed as the corrosion resistant materials for fabricating the waste package outer barrier and the drip shield, respectively for the proposed nuclear waste repository Yucca Mountain Project. In this work, the susceptibility of welded and annealed Alloy 22 (N06022) and Ti Grade 7 (UNS R52400) to crevice corrosion was studied by the Multiple Crevice Assembly (ASTM G78) method combined with surface morphological observation after four and eight weeks of exposure to the Basic Saturated Water (BSW-12) in a temperature range from 60 to 105 C. The susceptibility of the materials to crevice corrosion was evaluated based on the appearance of crevice attack underneath the crevice formers and the weight loss data. The results showed that, after exposed to BSW-12 for four and eight weeks, no obvious crevice attack was observed on these materials. The descaled weight loss increased with the increase in temperature for all materials. The weight loss, however, is believed to be caused by general corrosion, rather than crevice corrosion. There was no significant difference between the annealed and welded materials either. On the other hand, to conclude that these materials are immune to crevice corrosion in BSW-12 will require longer term testing.

  19. 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.

  20. 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.

  1. 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

  2. Performance Prediction for Large-Scale Nuclear Waste Repositories: Final Report

    SciTech Connect

    Glassley, W E; Nitao, J J; Grant, W; Boulos, T N; Gokoffski, M O; Johnson, J W; Kercher, J R; Levatin, J A; Steefel, C I

    2001-02-01

    embodied in the code accurately represents the state-of-the-art in modeling these processes, and that the conceptualization of the models used in the simulations honors the primary processes that are controlling these systems. Application of the code to a wide range of important and strategic problems has been undertaken. Particularly significant are results obtained concerning the evolution of a potential high level nuclear waste repository at Yucca Mountain, Nevada. In these simulations, the results suggest that fluid movement and chemical changes will be such as to encourage solute transport around the sides of the waste emplacement tunnels, thus minimizing the potential for seepage of water and dissolved salts into the tunnels. The results also indicate that the short term response of the geological system to waste emplacement will be complex and rapid, and will be most readily detected below waste emplacement tunnels. A successful monitoring program of repository performance during the early stages of the operational period would thus benefit by coordinating design and execution of sampling strategies with a simulation tool such as NUFT-C. Such an approach would allow efficient and cost-effective sampling strategies, and would facilitate interpretation of what will surely be complex and massive data sets.

  3. 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.

  4. Brine: a computer program to compute brine migration adjacent to a nuclear waste canister in a salt repository

    SciTech Connect

    Duckworth, G.D.; Fuller, M.E.

    1980-06-10

    This report presents a mathematical model used to predict brine migration toward a nuclear waste canister in a bedded salt repository. The mathematical model is implemented in a computer program called BRINE. The program is written in FORTRAN and executes in the batch mode on a CDC 7600. A description of the program input requirements and output available is included. Samples of input and output are given.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Geological repository for nuclear high level waste in France from feasibility to design within a legal framework

    SciTech Connect

    Voizard, Patrice; Mayer, Stefan; Ouzounian, Gerald

    2007-07-01

    Over the past 15 years, the French program on deep geologic disposal of high level and long-lived radioactive waste has benefited from a clear legal framework as the result of the December 30, 1991 French Waste Act. To fulfil its obligations stipulated in this law, ANDRA has submitted the 'Dossier 2005 Argile' (clay) and 'Dossier 2005 Granite' to the French Government. The first of those reports presents a concept for the underground disposal of nuclear waste at a specific clay site and focuses on a feasibility study. Knowledge of the host rock characteristics is based on the investigations carried out at the Meuse/Haute Marne Underground Research Laboratory. The repository concept addresses various issues, the most important of which relates to the large amount of waste, the clay host rock and the reversibility requirement. This phase has ended upon review and evaluation of the 'Dossier 2005' made by different organisations including the National Review Board, the National Safety Authority and the NEA International Review Team. By passing the 'new', June 28, 2006 Planning Act on the sustainable management of radioactive materials and waste, the French parliament has further defined a clear legal framework for future work. This June 28 Planning Act thus sets a schedule and defines the objectives for the next phase of repository design in requesting the submission of a construction authorization application by 2015. The law calls for the repository program to be in a position to commission disposal installations by 2025. (authors)

  10. 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)

  11. 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.

  12. 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.

  13. Coupled Multi-physical Simulations for the Assessment of Nuclear Waste Repository Concepts: Modeling, Software Development and Simulation

    NASA Astrophysics Data System (ADS)

    Massmann, J.; Nagel, T.; Bilke, L.; Böttcher, N.; Heusermann, S.; Fischer, T.; Kumar, V.; Schäfers, A.; Shao, H.; Vogel, P.; Wang, W.; Watanabe, N.; Ziefle, G.; Kolditz, O.

    2016-12-01

    As part of the German site selection process for a high-level nuclear waste repository, different repository concepts in the geological candidate formations rock salt, clay stone and crystalline rock are being discussed. An open assessment of these concepts using numerical simulations requires physical models capturing the individual particularities of each rock type and associated geotechnical barrier concept to a comparable level of sophistication. In a joint work group of the Helmholtz Centre for Environmental Research (UFZ) and the German Federal Institute for Geosciences and Natural Resources (BGR), scientists of the UFZ are developing and implementing multiphysical process models while BGR scientists apply them to large scale analyses. The advances in simulation methods for waste repositories are incorporated into the open-source code OpenGeoSys. Here, recent application-driven progress in this context is highlighted. A robust implementation of visco-plasticity with temperature-dependent properties into a framework for the thermo-mechanical analysis of rock salt will be shown. The model enables the simulation of heat transport along with its consequences on the elastic response as well as on primary and secondary creep or the occurrence of dilatancy in the repository near field. Transverse isotropy, non-isothermal hydraulic processes and their coupling to mechanical stresses are taken into account for the analysis of repositories in clay stone. These processes are also considered in the near field analyses of engineered barrier systems, including the swelling/shrinkage of the bentonite material. The temperature-dependent saturation evolution around the heat-emitting waste container is described by different multiphase flow formulations. For all mentioned applications, we illustrate the workflow from model development and implementation, over verification and validation, to repository-scale application simulations using methods of high performance computing.

  14. 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.

  15. 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.

  16. C-14 release and transport 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.

    1990-06-01

    The release of {sup 14}C as {sup 14}CO{sub 2} from partly failed spent fuel containers has been analyzed by the flow of gases into and out of the containers. This flow of gases is driven by pressure differences, which are in turn caused by heating by the spent fuel. In this analysis, the timing and size of holes in the containers are assumed to be given. A better means of predicting the time distribution and sizes of penetrations in nuclear waste containers is needed. For the purposes of far-field transport calculations, we have adopted release rates that are shown to be bonding for the large range of hole sizes studied. The transport of released {sup 14}CO{sub 2} has been analyzed by transport in equivalent porous medium. The peak {sup 14}CO{sub 2} concentration in pore gas at 350 m above the repository does not depend on the time of hole occurrence, although the time of penetration obviously affects the arrival and duration of exposure to {sup 14}C. Nor does water saturation have much effect on peak concentration. In this analysis we have used a constant gas Darcy velocity. We performed limited sensitivity analysis on gas Darcy velocity by using values one order of magnitude above and below the published value. This probably gives us bounds on the likely gas Darcy velocity. Our calculations show that essentially all the released {sup 14}C will reach the ground surface in less than one half-life of {sup 14}C. However, the quantities of {sup 14}C reaching the ground surface are so small that even if all containers fail at emplacement and conservative dose factors are used, the resultant inhalation dose to the maximally exposed individual is about 0.1% of natural background radiation. 14 refs., 18 figs., 3 tabs.

  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. 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.

  19. Estimation of waste package performance requirements for a nuclear waste repository in basalt

    SciTech Connect

    Wood, B J

    1980-07-01

    A method of developing waste package performance requirements for specific nuclides is described, and based on federal regulations concerning permissible concentrations in solution at the point of discharge to the accessible environment, a simple and conservative transport model, and baseline and potential worst-case release scenarios.

  20. 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.

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

    SciTech Connect

    Blacic, J.D.; Vaniman, D.T.; Bish, D.L.; Duffy, C.J.; Gooley, R.C.

    1986-08-01

    We have performed exploratory tests to investigate the effects of extended exposure of tuffs from Yucca Mountain, Nevada, to temperatures and pressures similar to those that will be encountered in a high-level nuclear waste repository. In a preliminary report we described statistically significant changes in strength properties and generally minor changes in porosity and grain density. In the present report we describe additional measurements that indicate possible changes in permeability (in one tuff type) after exposure for 2 to 6 months at temperatures from 80 to 180 C, confining pressures of 9.7 and 19.7 MPa, and water pore pressures of 0.5 and 19.7 MPa. Mineralogic examinations have established reactions involving dissolution of silica and feldspar minerals and possible conversion of clinoptilolite to mordenite. We conclude that rock properties important to the operation of a nuclear waste repository in tuff are likely to change over time when exposed to simulated repository conditions, and the details of these time-dependent processes should be investigated further.

  2. Nuclear waste repositories in salt mines: a new approach to safety assessment.

    PubMed

    Memmert, G

    1996-08-01

    The long-term safety of radioactive waste repositories in rock-salt mines in the deep underground benefits significantly from the barrier effect of overlying rocks. The concentrations of radioactive substances released from the repository and migrating in the aquifer up to the biosphere are greatly reduced during passage through these rocks. In former safety analyses of waste repositories this transport has generally been modelled as a combination of the involved phenomena, e.g. convection, dispersion, adsorption, etc. The data required for a numerical evaluation of the overall effect are obtained either as (conservative) estimates based on experience or are empirical, based mainly on laboratory experiments. The approach presented here is much simpler and entirely empirical, and therefore more transparent. It makes use of the fact that the groundwater in the overlying rocks always contains dissolved salt from the salt formation and carries it continuously into the receiving channels or the drainage system. The relation between the total amount of dissolved solids present in a certain subsurface catchment area and their steady-state concentration in the receiving channels is assumed to be equivalent to the relation between the given amount of radionuclides released from the repository and their concentration in the receiving channels, the latter leading to a certain radiation exposure of the population. Two versions of this approach are discussed: version (a) assumes a continuous stream of radionuclides released from the repository, and version (b) assumes a pulse release of radionuclides from the repository. A simple calculation using data from the Gorleben exploration leads to the inequality [equation: see text] where Cmax is the maximum radionuclide concentration (with respect to time) in the receiving channels and W (Bq) is the amount of radionuclides released from the respository in a very short time. Cmax obtained from (1), is supposed to be an upper limit of

  3. 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.

  4. 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

  5. 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.

  6. Numerical modeling of gas migration at a proposed repository for low and intermediate level nuclear wastes at Oberbauenstock, Switzerland

    SciTech Connect

    Pruess, K.

    1990-03-01

    Hydrologic impacts of corrosive gas release from a hypothetical L/ILW nuclear waste repository at Oberbauenstock are explored by means of numerical simulation. A schematic two dimensional vertical section through the mountain is modeled with the simulator TOUGH, which describes two-phase flow of water and gas in porous and fractured media. Two reference cases are considered which represent the formations as a porous and as a fractured-porous (dual permeability) medium, respectively. Both cases predict similar and rather modest pressure increases, from ambient 10 bars to near 25 bars at the repository level. These results are to be considered preliminary because important parameters affecting two-phase flow, such as relative permeabilities of a fractured medium, are not well known at present. 24 refs., 15 figs., 5 tabs.

  7. The Analytical Repository Source-Term (AREST) model: Analysis of spent fuel as a nuclear waste form

    SciTech Connect

    Apted, M.J.; Liebetrau, A.M.; Engel, D.W.

    1989-02-01

    The purpose of this report is to assess the performance of spent fuel as a final waste form. The release of radionuclides from spent nuclear fuel has been simulated for the three repository sites that were nominated for site characterization in accordance with the Nuclear Waste Policy Act of 1982. The simulation is based on waste package designs that were presented in the environmental assessments prepared for each site. Five distinct distributions for containment failure have been considered, and the release for nuclides from the UO/sub 2/ matrix, gap (including grain boundary), crud/surface layer, and cladding has been calculated with the Analytic Repository Source-Term (AREST) code. Separate scenarios involving incongruent and congruent release from the UO/sub 2/ matrix have also been examined using the AREST code. Congruent release is defined here as the condition in which the relative mass release rates of a given nuclide and uranium from the UO/sub 2/ matrix are equal to their mass ratios in the matrix. Incongruent release refers to release of a given nuclide from the UO/sub 2/ matrix controlled by its own solubility-limiting solid phase. Release of nuclides from other sources within the spent fuel (e.g., cladding, fuel/cladding gap) is evaluated separately from either incongruent or congruent matrix release. 51 refs., 200 figs., 9 tabs.

  8. 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.

  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.

  10. Methodology Used for Total System Performance Assessment of the Potential Nuclear Waste Repository at Yucca Mountain (USA)

    SciTech Connect

    E. Devibec; S.D. Sevougian; P.D. Mattie; J.A. McNeish; S. Mishra

    2001-03-15

    The U.S. Department of Energy and its contractors are currently evaluating a site in Nevada (Yucca Mountain) for disposal of high-level radioactive waste from U.S. commercial nuclear plants and U.S. government-owned facilities. The suitability of the potential geologic repository is assessed, based on its performance in isolating the nuclear waste from the environment. Experimental data and models representing the natural and engineered barriers are combined into a Total System Performance Assessment (TSPA) model [1]. Process models included in the TSPA model are unsaturated zone flow and transport, thermal hydrology, in-drift geochemistry, waste package degradation, waste form degradation, engineered barrier system transport, saturated zone flow and transport, and biosphere transport. Because of the uncertainty in the current data and in the future evolution of the total system, simulations follow a probabilistic approach. Multiple realization simulations using Monte Carlo analysis are conducted over time periods of up to one million years, which estimates a range of possible behaviors of the repository. The environmental impact is measured primarily by the annual dose received by an average member of a critical population group residing 20 km down-gradient of the potential repository. In addition to the nominal scenario, other exposure scenarios include the possibility of disruptive events such as volcanic eruption or intrusion, or accidental human intrusion. Sensitivity to key uncertain processes is analyzed. The influence of stochastic variables on the TSPA model output is assessed by ''uncertainty importance analysis'', e.g., regression analysis and classification tree analysis. Further investigation of the impact of parameters and assumptions is conducted through ''one-off analysis'', which consists in fixing a parameter at a particular value, using an alternative conceptual model, or in making a different assumption. Finally, robustness analysis evaluates

  11. 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.

  12. 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.

  13. 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.

  14. Modelling rock joint behavior from in situ block tests: implications for nuclear waste repository design

    SciTech Connect

    Barton, N.

    1982-09-01

    Simple, inexpensive index tests suitable for application to jointed core or jointed blocks of rock are described. These provide quantitative data on joint roughness, joint wall strength and residual friction angle, suitable for waste repository characterization. These three parameters form the basis of a new constitutive law of rock joint behavior which will enable numerical modellers to simulate the complete shear strength-displacement, dilation and closure of joints, including shear reversal and unloading cycles. Size effects are reviewed in detail and methods are developed for correcting the results of small scale tests to allow for limited sample size. The effects of shear displacement and dilation, normal closure and joint opening on permeability are modelled, so that fully coupled hydromechanical modelling can be achieved. The effects of extremely slow stress perturbations, periods of stick, and thermal loading on joint properties are also evaluated. The numerical modelling techniques are illustrated with numerous examples, and are validated against a large body of experimental data.

  15. 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.

  16. 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.

  17. Radiation effects on materials in the near-field of a nuclear waste repository. 1997 annual progress report

    SciTech Connect

    Wang, L.M.; Ewing, R.C.

    1997-11-25

    'Sheet silicates (e.g. micas and clays) are important constituents of a wide variety of geological formations such as granite, basalt, and sandstone. Sheet silicates, particularly clays such as bentonite are common materials in near-field engineered barriers in high-level nuclear waste (HLW) repositories. This is because migration of radionuclides from an underground HLW repository to the geosphere may be significantly reduced by sorption of radionuclides (e.g., Pu, U and Np) onto sheet silicates (e.g., clays and micas) that line the fractures and pores of the rocks along groundwater flowpaths. In addition to surface sorption, it has been suggested that some sheet silicates may also be able to incorporate many radionuclides, such as Cs and Sr, in the inter-layer sites of the sheet structure. However, theability of the sheet silicates to incorporate radionuclides and retard release and migration of radionuclides may be significantly affected by the near-field radiation due to the decay of fission products and actinides. for example, the unique properties of the sheet structures will be lost completely if the structure becomes amorphous due to irradiation effects. Thus, the study of irradiation effects on sheet-structures, such as structural damage and modification of chemical properties, are critical to the performance assessment of long-term repository behavior.'

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

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

    SciTech Connect

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

    1982-02-01

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

  4. Hydrothermal conditions and resaturation times in underground openings for a nuclear waste repository in the Umtanum flow at the Basalt Waste Isolation Project

    SciTech Connect

    Pruess, K.; Bodvarsson, G.

    1982-07-01

    Numerical simulation techniques have been used to study heat flow and pore fluid migration in the near field of storage tunnels and canister storage holes in a proposed high-level nuclear waste repository in the Umtanum Basalt at the Basalt Waste Isolation Project site at Hanford, Washington. Particular emphasis was placed on evaluating boiling conditions in the host rock. Sensitivity studies were performed to determine the influence of variations in critical site-specific parameters which are not presently accurately known. The results indicate that, even when rather extreme values are assumed for key hydrothermal parameters, the volume of rock dried by boiling of pore fluids is negligible compared to the volume of excavated openings. The time required for saturation of backfilling materials is thus controlled by the volume of the mined excavations. When realistic values for the parameters of the natural and man-made systems are used resaturation is predicted to occur within less than two years after backfilling is placed. The approximations used in the analyses, and their limitations, are discussed in the body of the report. Recommendations are made for additional studies of the thermohydrological behavior of a high-level nuclear waste repository. 31 references, 76 figures, 7 tables.

  5. 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.

  6. 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.

  7. Radio Active Waste Management: Underground Repository Method

    SciTech Connect

    Rudrapati Sandesh Kumar; Payal Shirvastava

    2002-07-01

    Finding a solution for nuclear waste is a key issue, not only for the protection of the environment but also for the future of the nuclear industry. Ten years from now, when the first decisions for the replacement of existing nuclear power plants will have to be made, The general public will require to know the solution for nuclear waste before accepting new nuclear plants. In other words, an acceptable solution for the management of nuclear waste is a prerequisite for a renewal of nuclear power. Most existing wastes are being stored in safe conditions waiting for permanent solution, with some exceptions in the former Eastern Bloc. Temporary surface or shallow storage is a well known technique widely used all over the world. A significant research effort has been made by the author of this paper in the direction of underground repository. The underground repository appears to be a good solution. Trying to transform dangerous long lived radionuclides into less harmful short lived or stable elements is a logical idea. It is indeed possible to incinerate or transmute heavy atoms of long lived elements in fast breeder reactors or even in pressurised or boiling water reactors. There are also new types of reactors which could be used, namely accelerator driven systems. High level and long lived wastes (spent fuel and vitrified waste) contain a mixture of high activity (heat producing) short lived nuclides and low activity long lived alpha emitting nuclides. To avoid any alteration due to temperature of the engineered or geological barrier surrounding the waste underground, it is necessary to store the packages on the surface for several decades (50 years or more) to allow a sufficient temperature decrease before disposing of them underground. In all cases, surface (or shallow) storage is needed as a temporary solution. This paper gives a detailed and comprehensive view of the Deep Geological Repository, providing a pragmatic picture of the means to make this method, a

  8. 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.

  9. Radiation effects on materials in the near-field of nuclear waste repository. 1998 annual progress report

    SciTech Connect

    Wang, L.M.; Ewing, R.C.

    1998-06-01

    'Site restoration activities at DOE facilities and the permanent disposal of nuclear waste generated at DOE facilities involve working with and within various types and levels of radiation fields. Once the nuclear waste is incorporated into a final form, radioactive decay will decrease the radiation field over geologic time scales, but the alpha-decay dose for these solids will still reach values as high as 10{sup 18} alpha-decay events/gm in periods as short as 1,000 years. This dose is well within the range for which important chemical (e.g., increased leach rate) and physical (e.g., volume expansion) changes may occur in crystalline ceramics. Release and sorption of long-lived actinides (e.g., {sup 237}Np) can provide a radiation exposure to backfill materials, and changes in important properties (e.g., cation exchange capacity) may occur. The objective of this research program is to evaluate the long term radiation effects in the materials in the near-field of a nuclear waste repository with accelerated experiments in the laboratory using energetic particles (electrons, ions and neutrons). Experiments on the microstructural evolution during irradiation of two important groups of materials, sheet silicates (e.g., clays) and zeolites (analcime), have been conducted; and studies of radiation-induced changes in chemical properties (e.g. cation exchange capacity) are underway. As of the mid-2nd year of the 3-year project, experiments on the microstructural evolution during irradiation of two important group of materials, sheet silicates (mica) and zeolites (analcime), have been conducted; and studies of radiation-induced changes in chemical properties (e.g., cation exchange capacity) are underway.'

  10. 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.

  11. SYNTHESIS AND PERFORMANCE OF FE-BASED AMORPHOUS ALLOYS FOR NUCLEAR WASTE REPOSITORY APPLICATIONS

    SciTech Connect

    Kaufman, L; Perepezko, J; Hildal, K

    2007-02-08

    In several Fe-based alloy systems it is possible to produce glasses with cooling rates as low as 100 K/s that exhibit outstanding corrosion resistance compared to typical crystalline alloys such as high-performance stainless steels and Ni-based C-22 alloy. Moreover, novel alloy compositions can be synthesized to maximize corrosion resistance (i.e. adding Cr and Mo) and to improve radiation compatibility (adding B) and still maintain glass forming ability. The applicability of Fe-based amorphous coatings in typical environments where corrosion resistance and thermal stability are critical issues has been examined in terms of amorphous phase stability and glass-forming ability through a coordinated computational analysis and experimental validation. Similarly, a novel computational thermodynamics approach has been developed to explore the compositional sensitivity of glass-forming ability and thermal stability. Also, the synthesis and characterization of alloys with increased cross-section for thermal neutron capture will be outlined to demonstrate that through careful design of alloy composition it is possible to tailor the material properties of the thermally spray-formed amorphous coating to accommodate the challenges anticipated in typical nuclear waste storage applications over tens of thousands of years in a variety of corrosive environments.

  12. 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.

  13. 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.

  14. 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.

  15. 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).

  16. 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.

  17. 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

  18. Application of Non-Human Biota Assessment Methodologies to the Assessment of Potential Impacts from a Nuclear Waste Repository

    SciTech Connect

    Smith, K.L.; Robinson, C.A.; Ikonen, A.T.K.

    2007-07-01

    The protection of the environment from the effects of ionising radiation has become increasingly more topical over the last few years as the intentions enshrined in international principles and agreements have become more binding through national and international law. For example, the Directive on impact of certain projects on the environment (EIA Directive 85/337/EEC) [CEC, 1985], amended in 1997 [CEC, 1997], places a mandatory requirement on all EU Member States to conduct environmental impact assessments for a range of project having potential impact on the environment, including radioactive waste disposal. Such assessments must consider humans, fauna and flora, the abiotic environment (soil, water, air), material assets and cultural heritage as well as the interactions between these factors. In Finland, Posiva Oy are responsible for the overall repository programme for spent nuclear fuel and, as such, are conducting the Safety Case Assessment for a proposed geological repository for nuclear waste. Within the European legislation framework, the Finnish regulatory body requires that the repository safety case assessment should include not only human radiological safety, but also an assessment of the potential impact upon populations of non-human biota. Specifically, the Safety Case should demonstrate that there will be: - no decline in the biodiversity of currently living populations; - no significant detriment to populations of fauna and flora; and, - no detrimental effects on individuals of domestic animals and rare plants and animals. At present, there are no internationally agreed criteria that explicitly address protection of the environment from ionising radiation. However, over recent years a number of assessment methodologies have been developed including, at a European level, the Framework for the Assessment of Environmental impact (FASSET) and Environmental Risks from Ionising Contaminants (ERICA). The International Committee on Radiation Protection

  19. 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.

  20. Geologic uncertainty in a regulatory environment: An example from the potential Yucca Mountain nuclear waste repository site

    NASA Astrophysics Data System (ADS)

    Rautman, C. A.; Treadway, A. H.

    1991-11-01

    Regulatory geologists are concerned with predicting the performance of sites proposed for waste disposal or for remediation of existing pollution problems. Geologic modeling of these sites requires large-scale expansion of knowledge obtained from very limited sampling. This expansion induces considerable uncertainty into the geologic models of rock properties that are required for modeling the predicted performance of the site. One method for assessing this uncertainty is through nonparametric geostatistical simulation. Simulation can produce a series of equiprobable models of a rock property of interest. Each model honors measured values at sampled locations, and each can be constructed to emulate both the univariate histogram and the spatial covariance structure of the measured data. Computing a performance model for a number of geologic simulations allows evaluation of the effects of geologic uncertainty. A site may be judged acceptable if the number of failures to meet a particular performance criterion produced by these computations is sufficiently low. A site that produces too many failures may be either unacceptable or simply inadequately described. The simulation approach to addressing geologic uncertainty is being applied to the potential high-level nuclear waste repository site at Yucca Mountain, Nevada, U.S.A. Preliminary geologic models of unsaturated permeability have been created that reproduce observed statistical properties reasonably well. A spread of unsaturated groundwater travel times has been computed that reflects the variability of those geologic models. Regions within the simulated models exhibiting the greatest variability among multiple runs are candidates for obtaining the greatest reduction in uncertainty through additional site characterization.

  1. 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.

  2. 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.

  3. 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.

  4. Performance assessments of nuclear waste repositories: A dialogue on their value and limitations

    SciTech Connect

    Ewing, R.C.; Tierney, M.S.; Konikow, L.F.; Rechard, R.P.

    1999-10-01

    This paper is a dialogue to explore the value and limitations of PA. Two skeptics acknowledge the utility of PA in organizing the scientific investigations that are necessary for confident siting and licensing of a repository; however, they maintain that the PA process, at least as it is currently implemented, is an essentially unscientific process with shortcomings that may provide results of limited use in evaluating actual effects on public health and safety. Conceptual uncertainties in a PA analysis can be so great that results can be confidently applied only over short time ranges, the antithesis of the purpose behind long-term, geologic disposal. Two proponents of PA agree that performance assessment is unscientific, but only in the sense that PA is an engineering analysis that uses existing scientific knowledge to support public policy decisions, rather than an investigation intended to increase fundamental knowledge of nature; PA has different goals and constraints than a typical scientific study. The proponents describe an ideal, six-step process for conducting generalized PA, here called probabilistic systems analysis (PSA); they note that virtually all scientific content of a PA is introduced during the model-building steps of a PSA; they content that a PA based on simple but scientifically acceptable mathematical models can provide useful and objective input to regulatory decision makers.

  5. 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.

  6. 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.

  7. Estimation of underground cavities stability for long-term safety of nuclear waste repository

    NASA Astrophysics Data System (ADS)

    Rogojnikov, O.; Mansurov, V.

    2003-04-01

    There is the increased interest to a problem of storages of radioactive waste creation in geological structures in present. Such projects are developed and the construction of these objects is conducted in many countries. This is caused by real, safety and economically acceptable character of radioactive waste underground isolation from human environment. Exploitation term of this objects is tens, hundreds and more years. The rock massif is the long acting natural barrier on a way of radionuclides distribution so the problem of ecological safety is long-term stability of storages and surrounding rock. Therefore one of the main problems is the development of evaluation and forecasting methods of underground structures supporting constructions long stability. The regularities of roof of cameras and pillars deformation and failure in time, depending on its geometric sizes, physical-mechanical properties of rocks, stress state and massif structure are obtained as result of mine research. On basis of kinetic theory of rock failure, creep theory and statistical analysis of experimental datas, which was obtained in mine conditions, the model of supporting constructions long-term strength is developed. This model allows to make an estimation and forecasting of underground structures current state evolution in time.

  8. 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.

  9. Interpretation by numerical modeling of data monitored at a cover for a nuclear waste repository

    NASA Astrophysics Data System (ADS)

    Gran, M.; Carrera, J.; Saaltink, M. W.

    2012-04-01

    Two pilot covers have been set up at the Spanish facility for disposal of low and intermediate-level radioactive waste located at El Cabril (southern Spain). Their objective is to test the effectiveness in reducing or preventing surface erosion and runoff, infiltration and biointrusion. They consist of multilayer systems that profit from capillary barrier concepts. A complete monitoring system involving more than 200 sensors has been installed. At the same time, a complete meteorological station records meteorological data. This information is used to define initial and boundary conditions of a numerical model and also to test its validity. Here we discuss results of a preliminary 1D non isothermal multiphase flow model with an atmospheric boundary (whose fluxes depend on meteorological data) at the top. Furthermore a sink-source term has been developed to simulate the effect of lateral flow caused by the steep slope (40%) of the cover. Joint analysis of numerical simulation results together with field data allows us to study the behaviour of the liquid, gas and energy fluxes in a layered slope and to study the effects of different hydraulic properties, capillary pressures and degrees of saturation of the materials on the magnitude and direction of these flows.

  10. Locating a Radioactive Waste Repository in the Ring of Fire

    NASA Astrophysics Data System (ADS)

    Apted, Mick; Berryman, Kelvin; Chapman, Neil; Cloos, Mark; Connor, Chuck; Kitayama, Kazumi; Sparks, Steve; Tsuchi, Hiroyuki

    2004-11-01

    The scientific, technical, and sociopolitical challenges of finding a secure site for a geological repository for radioactive wastes have created a long and stony path for many countries. Japan carried out many years of research and development before taking its first steps in site selection. The Nuclear Waste Management Organization of Japan (NUMO) began looking for a high-level waste repository site (HLW, vitrified residue from reprocessing power reactor fuel) 2 years ago. Over the next 10-20 years, NUMO hopes to find a site to dispose of ~20,000 tons of HLW in a robustly engineered repository constructed at a depth of several hundred meters.

  11. 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.

  12. Assessing materials (''Getters'') to immobilize or retard the transport of technetium through the engineered barrier system at the potential Yucca Mountain nuclear waste repository

    SciTech Connect

    Viani, B E

    1999-03-15

    Current performance assessment calculations show that technetium (Tc) and neptunium (Np) will deliver the major fraction of the radiation dose to the accessible environment from the potential Yucca Mountain nuclear waste repository. Therefore, materials that can immobilize or delay the transport of Tc or Np (getters) are being considered for addition to either the waste-package or the backfill adjacent to the waste-package. Of the two radionuclides, Tc presents the greater challenge in identifying a suitable getter material. This report identifies several materials that warrant further consideration for immobilizing and/or sorbing Tc as additives to the backfill, and recommends active carbon and an inorganic oxide for initial testing. Other materials, such as zero valent iron, might be useful as getters if they were placed in the waste package itself, a subject that merits further investigation.

  13. Effects of silica redistribution on performance of high-level nuclear waste repositories in saturated geologic formations

    SciTech Connect

    Verma, A.; Pruess, K.

    1985-11-01

    Evaluation of the thermohydrological conditions near high-level waste packages is needed for the design of the waste canister and for overall repository design and performance assessment. Most available studies in this area have assumed that the hydrologic properties of the host rock do not change in response to the thermal, mechanical or chemical effects caused by waste emplacement. However, the ramifications of this simplifying assumption have not been substantiated. We have studied dissolution and precipitation of silica in thermally driven flow systems, including changes in formation porosity and permeability. Using numerical simulation, we compare predictions of thermohydrological conditions with and without inclusion of silica redistribution effects. Two cases were studied, namely, a canister-scale problem, a repository-wide thermal convection problem, and different pore models were employed for the permeable medium (fractures with uniform or non-uniform cross sections). We find that silica redistribution generally has insignificant effects on host rock and canister temperatures, pore pressures, or flow velocites.

  14. 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.

  15. 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.

  16. 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).

  17. Progress in evaluation of radionuclide geochemical information developed by DOE high-level nuclear waste repository site projects. Annual report, October 1984-September 1985. Volume 4

    SciTech Connect

    Meyer, R.E.; Arnold, W.D.; Blencoe, J.G.; Jacobs, G.K.; Kelmers, A.D.; Seeley, F.G.; Whatley, S.K.

    1986-05-01

    Information pertaining to the potential geochemical behavior of radionuclides at candidate sites for a high-level radioactive waste repository, which is being developed by projects within the Department of Energy (DOE), is being evaluated by Oak Ridge National Laboratory for the Nuclear Regulatory Commission (NRC). During this report period, emphasis was placed on the evaluation of information pertinent to the Hanford site in southeastern Washington. Results on the sorption/solubility behavior of technetium, neptunium, and uranium in the basalt/water geochemical system are summarized and compared to the results of DOE. Also, summaries of results are reported from two geochemical modeling studies: (1) an evaluation of the information developed by DOE on the native copper deposits of Michigan as a natural analog for the emplacement of copper canisters in a repository in basalt, and (2) calculation of the solubility and speciation of radionuclides for representative groundwaters from the Yucca Mountain site in Nevada.

  18. 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.

  19. 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

  20. 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.

  1. A review of the available technologies for sealing a potential underground nuclear waste repository at Yucca Mountain, Nevada

    SciTech Connect

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

    1994-11-01

    The purpose of this report is to assess the availability of technologies to seal underground openings. The technologies are needed to seal the potential high-level radioactive waste repository at Yucca Mountain. Technologies are evaluated for three basic categories of seal components: backfill (general fill and graded fill), bulkheads, and grout curtains. Not only is placement of seal components assessed, but also preconditioning of the placement area and seal component durability. The approach taken was: First, review selected sealing case histories (literature searches and site visits) from the mining, civil, and defense industries; second, determine whether reasonably available technologies to seal the potential repository exist; and finally, identify deficiencies in existing technologies. It is concluded that reasonably available technologies do exist to place backfill, bulkheads, and grout curtains. Technologies also exist to precondition areas where seal components are to be placed. However, if final performance requirements are stringent for these engineered structures, some existing technologies may need to be developed. Deficiencies currently do exist in technologies that demonstrate the long-term durability and performance of seal components. Case histories do not currently exist that demonstrate the placement of seal components in greatly elevated thermal and high-radiation environments and in areas where ground support (rock bolts and concrete liners) has been removed. The as-placed, in situ material properties for sealing materials appropriate to Yucca Mountain are not available.

  2. 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.

  3. 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

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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)

  10. 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.

  11. 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.

  12. Progress in evaluation of radionuclide geochemical information developed by DOE high-level nuclear waste repository site projects: report for January-March 1985. Volume 2

    SciTech Connect

    Kelmers, A.D.; Seeley, F.G.; Arnold, W.D.; Blencoe, J.G.; Meyer, R.E.; Jacobs, G.K.; Whatley, S.K.

    1985-09-01

    Geochemical information relevant to the retention of radionuclides by the Hanford Site (in basalt) and the Yucca Mountain site (in tuff), candidate high-level nuclear waste geologic repositories being developed by US Department of Energy (DOE) projects, is being evaluated by Oak Ridge National Laboratory (ORNL) for the US Nuclear Regulatory Commission (NRC). Our evaluation of the sorption of technetium by basalt/groundwater systems was essentially completed this quarter and the results summarized; we conclude that the experimental methodology and results reported by the DOE for the Hanford Site have not conclusively established that significant retardation of technetium migration may be provided by phases present in the basalts of the Hanford Site. We have shown that sodium boltwoodite is the saturating uranium solid phase in two basalt/groundwater systems. Because thermodynamic data are not available for sodium boltwoodite, calculated solubilities for uranium are erroneous in these systems. Results of radionuclide solubility/speciation calculations, published by the DOE for the Yucca Mountain site, were evaluated this quarter under our geochemical modeling task. We express concerns relative to the inherent limitations of such calculations. Samples of Yucca Mountain tuff and J-13 well water were received for use in our planned radionuclide sorption/solubility experiments. These Yucca Mountain materials will be used to evaluate radionuclide sorption and apparent concentration limit values published by the Nevada Nuclear Waste Storage Investigations (NNWSI) project. 40 refs., 5 figs., 16 tabs.

  13. 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

  14. Role of U.S. Nuclear Regulatory Commission`s On-Site Representatives in pre-licensing activities for a high-level radioactive waste repository

    SciTech Connect

    Justus, P.S.; Gilray, J.

    1994-12-31

    Under the Nuclear Waste Policy Act, the US Department of Energy and the US Nuclear Regulatory Commission are required to consult with each other prior to DOE`s submittal of a license application to construct a high-level radioactive waste repository. DOE entered into an agreement which, in part, enabled NRC On-Site Representatives to be stationed at a high-level waste candidate site {open_quotes}principally to serve as a point of prompt informational exchange and consultation and to preliminary identify concerns about such investigations relating to potential licensing issues.{close_quotes} On-Site Representatives` direct observation of site characterization activities including construction of an underground studies facility (at Yucca Mountain, NV candidate site) provides NRC staff opportunities to help ensure that DOE will develop data which are appropriate to determine if the site will safely isolate waste and which will be defensible in a License Application. The On-Site Representatives, through supervision and input from the Division of High-Level Waste Management, may consult with the DOE site project office and its contractor staff on items pertaining to management and program controls necessary to satisfy NRC licensing needs, such as demonstrated application of procedural controls and technical data that will support a License Application. The On-Site Representatives interact with DOE through consultations with project staff, quality assurance workshops, observations of reviews of computer software and Q-List considerations, responses to audit and surveillance observations and day-to-day contact with DOE site management, QA staff, and technical investigators.

  15. 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

  16. 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.

  17. 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.

  18. 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)

  19. Military nuclear waste disposal

    NASA Astrophysics Data System (ADS)

    Robb, David W.

    1984-04-01

    A National Research Council (NRC) panel has endorsed a plan for a proposed underground military nuclear waste disposal facility located on a site near Carlsbad, N.M. The Department of Energy (DOE) asked NRC to evaluate the geologic suitability of the site.The NRC panel, chaired by Frank L. Parker of Vanderbilt University, concluded in its final report that “the important issues about the geology of the site have been resolved…” Those issues include the purity and volume of salt, the absence of brine pockets at the repository horizon in the areas excavated, the absence of breccia pipes and of toxic gases, and the nearly horizontal bedding of the salt. Thick underground salt beds have long been considered prime candidates for nuclear waste repositories. The existence of salt beds is believed to indicate long-term stability. In addition, the salt is flexible and will seal cracks and discontinuities over time.

  20. Progress in evaluation of radionuclide geochemical information developed by DOE high-level nuclear waste repository site projects. Report for April-June 1985. Volume 3

    SciTech Connect

    Kelmers, A.D.; Arnold, W.D.; Blencoe, J.G.; Meyer, R.E.; Jacobs, G.K.; Whatley, S.K.

    1986-02-01

    Geochemical information relevant to the potential mobility of radionuclides at the Hanford Site and the Yucca Mountain site, candidate sites for high-level nuclear waste geologic repositories being developed by Department of Energy projects, is being evaluated by Oak Ridge National Laboratory (ORNL) for the US Nuclear Regulatory Commission. Neptunium(V) sorption isotherms in three different basalt/synthetic groundwater systems were initiated this quarter. Uranium(VI) sorption isotherms were completed with McCoy Canyon basalt and synthetic groundwater GR-2. The control of U(VI) solutions at a level of {similar_to}10{sup -4} mol/L is apparently dominated by the precipitation of sodium boltwoodite. Different apparent concentration limits for uranium were obtained with GR-2 and GR-4 solutions. The results suggest that uranium sorption/solubility behavior could be substantially different in the various basalt units likely to be encountered by groundwater during migration from the waste package to the accessible environment. The EQ3/6 software package was implemented and tested on the ORNL computer system. 13 refs., 2 figs., 1 tab.

  1. Progress in evaluation of radionuclide geochemical information developed by DOE high-level nuclear waste repository site projects; Report for October 1987--June 1989

    SciTech Connect

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

    1989-08-01

    Information that is being developed by projects within the Department of Energy (DOE) pertinent to the potential geochemical behavior of radionuclides at candidate sites for a high-level radioactive waste repository is being evaluated by Oak Ridge National Laboratory (ORNL) for the Nuclear Regulatory Commission (NRC). During this report period, all experiments were conducted with tuff from the proposed high-level nuclear waste site at Yucca Mountain, Nevada. The principal emphasis in this report period was on column studies of migration of uranium and technetium in water from well J-13 at the Yucca Mountain site. Columns 1 cm in diameter and about 5 cm long were constructed and carefully packed with ground tuff. The characteristics of the columns were tested by determination of elution curves of tritium and TcO{sub 4}{sup {minus}}. Elution peaks obtained in past studies with uranium were asymmetrical and the shapes were often complex, observations that suggested irreversibilities in the sorption reaction. To try to understand these observations, the effects of flow rate and temperature on uranium migration were studied in detail. Sorption ratios calculated from the elution peaks became larger as the flow rate decreased and as the temperature increased. These observations support the conclusion that the sorption of uranium is kinetically hindered. To confirm this, batch sorption ratio experiments were completed for uranium as a function of time for a variety of conditions.

  2. Review and analysis of hydrogeologic conditions near the site of a potential nuclear-waste repository, Eddy and Lea counties, New Mexico

    USGS Publications Warehouse

    Mercer, Jerry W.; Orr, Brennon R.

    1977-01-01

    This interim report reviews and summarizes the hydrogeology of rocks associated with the Permian salt beds (Castile and Salado Formations) of Los Medanos area in southeastern New Mexico. The information will be considered, together with other factors, in the preparation of an analysis of the impact of a potential nuclear-waste repository on the environment. Most of the geologic units in and adjacent to the Permian salt deposits are characterized by low permeabilities and highly mineralized water. Sandstone of the Delaware Mountain Group, which underlies the salt, has an average hydraulic conductivity of 0.16 ft/d and an average porosity of 15.65 percent. Flow is north-northeastward toward the margin of the Capitan Limestone, at velocities ranging from 0.0005 to 0.0008 ft/d. The Capitan Limestone, a relatively high yielding limestone-reef aquifer adjacent to the study area, has transmissivity values ranging from 500 sq ft/d to 10,000 sq ft/d and an average hydraulic conductivity of about 5 ft/d. Water movement west of the Pecos River is northeastward in the reef, with discharge at Carlsbad Springs. East of the Pecos River, water moves at very low rates and the direction of movement is uncertain. The Castile and Salado Formations, which might be used to contain the nuclear waste, have a few isolated pockets of brine and gas, but generally transmit little or no ground water. (Woodard-USGS)

  3. 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.

  4. Nuclear Waste Management under Approaching Disaster: A Comparison of Decommissioning Strategies for the German Repository Asse II.

    PubMed

    Ilg, Patrick; Gabbert, Silke; Weikard, Hans-Peter

    2016-06-14

    This article compares different strategies for handling low- and medium-level nuclear waste buried in a retired potassium mine in Germany (Asse II) that faces significant risk of uncontrollable brine intrusion and, hence, long-term groundwater contamination. We survey the policy process that has resulted in the identification of three possible so-called decommissioning options: complete backfilling, relocation of the waste to deeper levels in the mine, and retrieval. The selection of a decommissioning strategy must compare expected investment costs with expected social damage costs (economic, environmental, and health damage costs) caused by flooding and subsequent groundwater contamination. We apply a cost minimization approach that accounts for the uncertainty regarding the stability of the rock formation and the risk of an uncontrollable brine intrusion. Since economic and health impacts stretch out into the far future, we examine the impact of different discounting methods and rates. Due to parameter uncertainty, we conduct a sensitivity analysis concerning key assumptions. We find that retrieval, the currently preferred option by policymakers, has the lowest expected social damage costs for low discount rates. However, this advantage is overcompensated by higher expected investment costs. Considering all costs, backfilling is the best option for all discounting scenarios considered.

  5. Cost analysis of German waste repositories

    SciTech Connect

    Berg, H.P.; Debski, H.J.

    1993-12-31

    In forecasting costs of final disposal for radioactive waste, the determined disposal concept and operational aspects such as the necessary amount for personnel to operate the repository are important. Even for the German deep geological concept, there are large differences resulting from the assessment to select an already existing mine or a completely new formation as a disposal site. Based on actual planning, the expected total costs of the running waste repository projects in the Federal Republic of Germany are presented including their distribution to single aspects like project management, underground investigation, licensing work and construction. Moreover, the actual expenditures for the different waste repositories are given and as far as possible the prices per m{sup 3}.

  6. 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.

  7. 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.

  8. 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.

  9. Use of a Dual-Structure Constitutive Model for Predicting the Long-Term Behavior of an Expansive Clay Buffer in a Nuclear Waste Repository

    DOE PAGES

    Vilarrasa, Víctor; Rutqvist, Jonny; Blanco Martin, Laura; ...

    2015-12-31

    Expansive soils are suitable as backfill and buffer materials in engineered barrier systems to isolate heat-generating nuclear waste in deep geological formations. The canisters containing nuclear waste would be placed in tunnels excavated at a depth of several hundred meters. The expansive soil should provide enough swelling capacity to support the tunnel walls, thereby reducing the impact of the excavation-damaged zone on the long-term mechanical and flow-barrier performance. In addition to their swelling capacity, expansive soils are characterized by accumulating irreversible strain on suction cycles and by effects of microstructural swelling on water permeability that for backfill or buffer materialsmore » can significantly delay the time it takes to reach full saturation. In order to simulate these characteristics of expansive soils, a dual-structure constitutive model that includes two porosity levels is necessary. The authors present the formulation of a dual-structure model and describe its implementation into a coupled fluid flow and geomechanical numerical simulator. The authors use the Barcelona Basic Model (BBM), which is an elastoplastic constitutive model for unsaturated soils, to model the macrostructure, and it is assumed that the strains of the microstructure, which are volumetric and elastic, induce plastic strain to the macrostructure. The authors tested and demonstrated the capabilities of the implemented dual-structure model by modeling and reproducing observed behavior in two laboratory tests of expansive clay. As observed in the experiments, the simulations yielded nonreversible strain accumulation with suction cycles and a decreasing swelling capacity with increasing confining stress. Finally, the authors modeled, for the first time using a dual-structure model, the long-term (100,000 years) performance of a generic heat-generating nuclear waste repository with waste emplacement in horizontal tunnels backfilled with expansive clay and

  10. Use of a Dual-Structure Constitutive Model for Predicting the Long-Term Behavior of an Expansive Clay Buffer in a Nuclear Waste Repository

    SciTech Connect

    Vilarrasa, Víctor; Rutqvist, Jonny; Blanco Martin, Laura; Birkholzer, Jens

    2015-12-31

    Expansive soils are suitable as backfill and buffer materials in engineered barrier systems to isolate heat-generating nuclear waste in deep geological formations. The canisters containing nuclear waste would be placed in tunnels excavated at a depth of several hundred meters. The expansive soil should provide enough swelling capacity to support the tunnel walls, thereby reducing the impact of the excavation-damaged zone on the long-term mechanical and flow-barrier performance. In addition to their swelling capacity, expansive soils are characterized by accumulating irreversible strain on suction cycles and by effects of microstructural swelling on water permeability that for backfill or buffer materials can significantly delay the time it takes to reach full saturation. In order to simulate these characteristics of expansive soils, a dual-structure constitutive model that includes two porosity levels is necessary. The authors present the formulation of a dual-structure model and describe its implementation into a coupled fluid flow and geomechanical numerical simulator. The authors use the Barcelona Basic Model (BBM), which is an elastoplastic constitutive model for unsaturated soils, to model the macrostructure, and it is assumed that the strains of the microstructure, which are volumetric and elastic, induce plastic strain to the macrostructure. The authors tested and demonstrated the capabilities of the implemented dual-structure model by modeling and reproducing observed behavior in two laboratory tests of expansive clay. As observed in the experiments, the simulations yielded nonreversible strain accumulation with suction cycles and a decreasing swelling capacity with increasing confining stress. Finally, the authors modeled, for the first time using a dual-structure model, the long-term (100,000 years) performance of a generic heat-generating nuclear waste repository with waste emplacement in horizontal tunnels backfilled with expansive clay and hosted in a

  11. 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

  12. 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.

  13. Modeling of Coupled Thermo-Hydro-Mechanical-Chemical Processes for Bentonite in a Clay-rock Repository for Heat-generating Nuclear Waste

    NASA Astrophysics Data System (ADS)

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

    2016-12-01

    Engineered Barrier Systems (EBS) that include a bentonite-based buffer are designed to isolate the high-level radioactive waste emplaced in tunnels in deep geological formations. The heat emanated from the waste can drive the moisture flow transport and induce strongly coupled Thermal (T), Hydrological (H), Mechanical (M) and Chemical (C) processes within the bentonite buffer and may also impact the evolution of the excavation disturbed zone and the sealing between the buffer and walls of an emplacement tunnel The flow and contaminant transport potential along the disturbed zone can be minimized by backfilling the tunnels with bentonite, if it provides enough swelling stress when hydrated by the host rock. The swelling capability of clay minerals within the bentonite is important for sealing gaps between bentonite block, and between the EBS and the surrounding host rock. However, a high temperature could result in chemical alteration of bentonite-based buffer and backfill materials through illitization, which may compromise the function of these EBS components by reducing their plasticity and capability to swell under wetting. Therefore, an adequate THMC coupling scheme is required to understand and to predict the changes of bentonite for identifying whether EBS bentonite can sustain higher temperatures. More comprehensive links between chemistry and mechanics, taking advantage of the framework provided by a dual-structure model, named Barcelona Expansive Model (BExM), was implemented in TOUGHREACT-FLAC3D and is used to simulate the response of EBS bentonite in in clay formation for a generic case. The current work is to evaluate the chemical changes in EBS bentonite and the effects on the bentonite swelling stress under high temperature. This work sheds light on the interaction between THMC processes, evaluates the potential deterioration of EBS bentonite and supports the decision making in the design of a nuclear waste repository in light of the maximum allowance

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Neutron transmutation of nuclear waste

    NASA Astrophysics Data System (ADS)

    Hoffman, Edward Albert

    Two metal fueled sub-critical fast reactor concepts, cooled by PbLi and PbBi, respectively, for a Fusion Transmutation of Waste Reactor (FTWR) were developed. Heat removal, radiation damage, etc. design constraints were applied to the FTWR to ensure a realistic and credible design. The standard linear stability model for critical systems was extended for evaluation of the linear stability of sub-critical systems, and the FTWR was shown to be stable to power excursions even when substantial positive fuel and coolant temperature coefficients exist. The reactor design concepts were calculated to remain subcritical for a wide range of off-normal conditions. Fuel cycle analyses were performed to evaluate the impacts of further transmutation of spent nuclear fuel on high-level and low-level waste mass flows into repositories, on the composition and toxicity of the high-level waste, on the capacity of high-level waste repositories, and on the proliferation-resistance of the high-level waste. Storage intact of LWR spent nuclear fuel, a single recycle in a LWR of the plutonium as MOX fuel, and the repeated recycle of the transuranics in critical and sub-critical fast reactors are compared. Sub-critical reactors based on both accelerator and fusion neutron sources were considered. The overall conclusions are that repeated recycling of the transuranics from spent nuclear fuel would significantly increase the capacity of high-level waste repositories per unit of nuclear energy produced, significantly increase the nuclear energy production per unit mass of uranium ore mined, significantly reduce the radio-toxicity of the waste streams per unit of nuclear energy produced, and significantly enhance the proliferation-resistance of the material stored in high-level waste repositories.

  1. Progress in evaluation of radionuclide geochemical information developed by DOE high-level nuclear waste repository site projects: Report for April 1986-September 1987

    SciTech Connect

    Meyer, R.E.; Arnold, W.D.; Blencoe, J.G.; O`Kelley, G.D.; Land, J.F.

    1988-02-01

    Experiments were conducted with tuff from the proposed high-level nuclear waste site at Yucca Mountain, Nevada. Batch sorption ratio determinations were conducted for strontium, cesium, uranium, and technetium onto samples of tuff using real and synthetic groundwater J-13. There were no significant differences in sorption ratios in experiments with real and synthetic groundwater. Columns 1 cm in diameter and about 5 cm long were constructed, and experiments were conducted with the objective of correlating the results of batch and the column experiments. The characteristics of the columns were tested by determination of elution curves in J-13 containing tritium and technetium as the TcO{sub 4}{sup -} ion. For strontium and cesium, fairly good correlation between values of the sorption ratio obtained by the two methods was observed. Little or no technetium sorption was observed with either method. The elution peaks obtained with neptunium and uranium were asymmetrical and the shapes were often complex, observations which suggest irreversibilities in the sorption reaction. An experiment was performed to provide information on the compositions of the first groundwaters that will contact waste canisters in a tuff-hosted repository after very near field temperatures have cooled to below 100{degree}C. Synthetic groundwater J-13 was slowly dripped onto a slab of tuff maintained at 95-100{degree}C, and the result was a thin encrustation of solids on the slab as the water evaporated. Fresh J-13 groundwater was then allowed to contact the encrustation in a vessel maintained at 90{degree}C. The principal result of the experiment was a significant loss of calcium and magnesium from the fresh J-13 groundwater.

  2. 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.

  3. 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.

  4. 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.

  5. Managing nuclear waste from power plants

    SciTech Connect

    Keeney, R.L.; Winterfeldt, D. von

    1994-02-01

    National strategies to manage nuclear waste from commercial nuclear power plants are analyzed and compared. The current strategy is to try to operate a repository at Yucca Mountain, Nevada, to dispose storage at a centralized facility or next to nuclear power plants. If either of these is pursued now, the analysis assumes that a repository will be built in 2100 for waste not subsequently put to use. The analysis treats various uncertainties: whether a repository at Yucca Mountain would be licensed, possible theft and misuse of the waste, innovations in repository design and waste management, the potential availability of a cancer cure by 2100, and possible future uses of nuclear waste. The objectives used to compare alternatives include concerns for health and safety, environmental and socioeconomic impacts, and direct economic costs, as well as equity concerns (geographical, intergenerational, and procedural), indirect economic costs, as well as equity concerns (geographical, intergenerational, and procedural), indirect economic costs to electricity ratepayers, federal government responsibility to manage nuclear waste, and implications of theft and misuse of nuclear waste. The analysis shows that currently building an underground repository at Yucca Mountain is inferior to other available strategies by the equivalent of $10,000 million to $50,000 million. This strongly suggests that this policy should be reconsidered. A more detailed analysis using the framework presented would help to define a new national policy to manage nuclear waste. 36 refs., 3 figs., 17 tabs.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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.

    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 through 2009 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 . 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) Regulatory requirements and related federal policy in laws and court decisions, (c) Presidential and agency directives, (c) technical milestones of implementing institutions, and (d) critiques of the Yucca Mountain Project 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 Safety on the performance assessment for the Yucca Mountain license

  12. Nuclear Waste Disposal: Alternatives to Yucca Mountain

    DTIC Science & Technology

    2009-02-06

    permanent high-level nuclear waste repository in 1987, following years of controversy over the site -selection process. Over the strenuous objections of...contending in an issue statement that he and now-Vice President Biden “do not believe that Yucca Mountain is a suitable site .” Under the current nuclear ...to Yucca Mountain would be indefinite on- site storage of nuclear waste at reactor sites and other nuclear facilities. Private central storage

  13. Development and application of a quality assurance system for waste repositories

    SciTech Connect

    Beckmerhagen, I.; Berg, H.P.

    1996-09-01

    A large set of requirements are developed for the structures, systems and components of a waste repository. These requirements cover different regulations concerning planning, design, construction, operation and decommissioning of a waste repository as well as nuclear-specific requirements on the design of the plant. The implementation of a quality assurance (QA) system is an essential task in order to ensure that the requirements are fulfilled by systematic means. The QA system for the German repositories for radioactive waste is built up as a hierarchic system and described in more detail in particular covering aspects like maintenance of QA relevant systems, structures and components as well as the procedure in case of changes. For the operational phase of a repository a separate site-specific manual had to be developed. Such a manual has been elaborated for the operation of the Morsleben repository; main topics of this manual are presented.

  14. 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)

  15. 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)

  16. Nuclear waste forms for actinides.

    PubMed

    Ewing, R C

    1999-03-30

    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.

  17. 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.

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

    SciTech Connect

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

    1984-12-01

    The Nuclear Waste Policy Act of 1982 (Public Law 97-425) provides for the development of repositories for the disposal of high-level radioactive waste and spent nuclear fuel and requires the Secretary of Energy to evaluate five potential repository sites. One factor that is to be examined is transportation of radioactive materials to such a repository and whether transportation might be affected by shipments to a defense-only repository, or to one that accepts both defense and commercial waste. In response to this requirement, The Department of Energy has undertaken an evaluation of the cost and risk associated with the potential shipments. Two waste-flow scenarios are considered which are related to the total quantity of defense high-level waste which will be placed in a repository. The low-flow case is based on a total of 6700 canisters being transported from one site, while the high-flow case assumes that a total of 20,000 canisters will be transported from three sites. For the scenarios considered, the estimated shipping costs range from $105 million to $257 million depending upon the mode of transport and the repository location. The total risks associated with shipping defense high-level waste to a repository are estimated to be significantly smaller than predicted for other transportation activities. In addition, the cost of shipping defense high-level waste to a repository does not depend on whether the site is a defense-only or a commercial repository. Therefore, the transportation considerations are not a basis for the selection of one of the two disposal options.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Total system performance predictions (TSPA-1995) for the potential high-level waste repository at Yucca Mountain

    SciTech Connect

    Sevougian, S.D.; Andrews, R.W.; McNeish, J.A.

    1996-06-01

    The management and operating contractor for the potential high-level nuclear waste repository at Yucca Mountain, Nevada, has been recently completed a new performance assessment of the ability of the repository to isolate and contain nuclear waste for long time periods (up to 1,000,000 years). Sensitivity analyses determine the most important physical parameters and processes, using the most current information and models.

  8. 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.

  9. Insights to Repository Performance Through Study of a Nuclear Test Site

    SciTech Connect

    Smith, D K; Kersting, A B; Thompson, J L; Finnegan, D L

    2000-01-14

    United States high-level nuclear waste from nuclear weapons production, naval propulsion programs, and the processing of commercial spent nuclear fuels is scheduled for immobilization in glass waste forms prior to permanent disposal in a mined geologic repository. Considerable attention has been directed to assessments of the subsequent long-term release of radionuclides from a repository under saturated and partially saturated conditions. Credible predictions of dose from a repository rely on insights to radionuclide sequestration in the glass, mechanisms of glass degradation, and radionuclide solubility and transport in the near-field. Underground nuclear test sites offer an unprecedented opportunity to evaluate processes relevant to repository performance in the absence of engineered barriers. Radionuclide migration programs at the Nevada Test Site represent a twenty-five year investment in the systematic investigation of the diverse radiologic source term from weapons testing and the evolution of the hydrologic source term which includes radionuclides dissolved in or otherwise available for transport by groundwater. The geology, hydrology, and geochemistry of the Nevada Test Site which includes the proposed Yucca Mountain repository provides an ideal natural laboratory to assess long-term radionuclide transport in the near and far-field. The Yucca Mountain repository shares with adjacent testing areas the following features: correlative volcanic geology, an identical tectonic and structural setting, similar recharge and climate, and a thick fractured unsaturated zone. In many cases nuclear tests are more than thirty years old and the hydrologic source term has geochemically evolved toward equilibrium during this time.

  10. 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

  11. 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.

  12. The Morsleben repository -- Waste acceptance requirements and radioactive wastes to be disposed of

    SciTech Connect

    Noack, W.; Kugel, K.; Brennecke, P.

    1995-12-31

    In the Federal Republic of Germany it is intended to dispose of all kinds of radioactive waste in deep geological formations. The Morsleben repository is used for the disposal of low and intermediate level radioactive waste mainly containing radionuclides with short half lives. This facility constructed and operated in the days of the former GDR is operated by the Federal Office for Radiation Protection. New safety assessments have been performed with regard to further operation since 1990. The safety assessment concerning normal operation and assumed incidents, radiological long-term safety and nuclear critically safety, was based on a broader data base and more realistic scenarios and models compared to previous safety assessments. Consequently, the existing waste acceptance requirements being a part of the operation license were specified in detail. On the basis of the effective waste acceptance requirements about 15,800 m{sup 3} radioactive wastes have been emplaced in the Morsleben repository corresponding to a total activity of 6.5 {times} 10{sup 14}Bq. During the validity of the existing license for continuous operation up to June 2000 it is planned to dispose of 40,000 m{sup 3} radioactive waste.

  13. Numerical study of the thm effects on the near-field safety of a hypothetical nuclear waste repository - bmt1 of the decovalex iii project. part 1: conceptualization and characterization of the problems and summary of results

    SciTech Connect

    Chijimatsu, M.; Nguyen, T.S.; Jing, L.; De Jonge, J.; Kohlmeier, M.; Millard, A.; Rejeb, A.; Rutqvist, J.; Souley, M.; Sugita, Y.

    2004-06-30

    Geological disposal of the spent nuclear fuel uses often the concept of multiple barrier systems. In order to predict the performance of these barriers, mathematical models have been developed, verified and validated against analytical solutions, laboratory tests and field experiments within the international DECOVALEX III project. These models in general consider the full coupling of thermal (T), hydraulic (H) and mechanical (M) processes that would prevail in the geological media around the repository. For Bench Mark Test no. 1 (BMT1) of the DECOVALEX III project, seven multinational research teams studied the implications of coupled THM processes on the safety of a hypothetical nuclear waste repository at the near-field and are presented in three accompany papers in this issue. This paper is the first of the three companion papers, which provides the conceptualization and characterization of the BMT1 as well as some general conclusions based on the findings of the numerical studies. It also shows the process of building confidence in the mathematical models by calibration with a reference T-H-M experiment with realistic rock mass conditions and bentonite properties and measured outputs of thermal, hydraulic and mechanical variables.

  14. 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.

  15. A Multi-Parametric Device with Innovative Solid Electrodes for Long-Term Monitoring of pH, Redox-Potential and Conductivity in a Nuclear Waste Repository.

    PubMed

    Daoudi, Jordan; Betelu, Stephanie; Tzedakis, Theodore; Bertrand, Johan; Ignatiadis, Ioannis

    2017-06-13

    We present an innovative electrochemical probe for the monitoring of pH, redox potential and conductivity in near-field rocks of deep geological radioactive waste repositories. The probe is composed of a monocrystalline antimony electrode for pH sensing, four AgCl/Ag-based reference or Cl(-) selective electrodes, one Ag₂S/Ag-based reference or S(2-) selective electrode, as well as four platinum electrodes, a gold electrode and a glassy-carbon electrode for redox potential measurements. Galvanostatic electrochemistry impedance spectroscopy using AgCl/Ag-based and platinum electrodes measure conductivity. The use of such a multi-parameter probe provides redundant information, based as it is on the simultaneous behaviour under identical conditions of different electrodes of the same material, as well as on that of electrodes made of different materials. This identifies the changes in physical and chemical parameters in a solution, as well as the redox reactions controlling the measured potential, both in the solution and/or at the electrode/solution interface. Understanding the electrochemical behaviour of selected materials thus is a key point of our research, as provides the basis for constructing the abacuses needed for developing robust and reliable field sensors.

  16. A Multi-Parametric Device with Innovative Solid Electrodes for Long-Term Monitoring of pH, Redox-Potential and Conductivity in a Nuclear Waste Repository

    PubMed Central

    Daoudi, Jordan; Betelu, Stephanie; Tzedakis, Theodore; Bertrand, Johan; Ignatiadis, Ioannis

    2017-01-01

    We present an innovative electrochemical probe for the monitoring of pH, redox potential and conductivity in near-field rocks of deep geological radioactive waste repositories. The probe is composed of a monocrystalline antimony electrode for pH sensing, four AgCl/Ag-based reference or Cl− selective electrodes, one Ag2S/Ag-based reference or S2− selective electrode, as well as four platinum electrodes, a gold electrode and a glassy-carbon electrode for redox potential measurements. Galvanostatic electrochemistry impedance spectroscopy using AgCl/Ag-based and platinum electrodes measure conductivity. The use of such a multi-parameter probe provides redundant information, based as it is on the simultaneous behaviour under identical conditions of different electrodes of the same material, as well as on that of electrodes made of different materials. This identifies the changes in physical and chemical parameters in a solution, as well as the redox reactions controlling the measured potential, both in the solution and/or at the electrode/solution interface. Understanding the electrochemical behaviour of selected materials thus is a key point of our research, as provides the basis for constructing the abacuses needed for developing robust and reliable field sensors. PMID:28608820

  17. 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.

  18. 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.

  19. 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

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

    SciTech Connect

    Berwald, D.; Favale, A.; Myers, T.

    1995-10-01

    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

    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.

  2. 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.

  3. 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.

  4. Application of the Scoping of Options and Analyzing Risk Model (SOAR) in the Modeling of Radionuclide Movement and Dose Calculation for a Hypothetical Deep Geological Repository for Nuclear Fuel Wastes

    NASA Astrophysics Data System (ADS)

    Lei, S.; Osborne, P.

    2016-12-01

    The Scoping of Options and Analyzing Risk (SOAR) model was developed by the U.S. Nuclear Regulatory Commission staff to assist in their evaluation of potential high-level radioactive waste disposal options. It is a 1-D contaminant transport code that contains a biosphere module to calculate mass fluxes and radiation dose to humans. As part of the Canadian Nuclear Safety Commission (CNSC)'s Coordinated Assessment Program to assist with the review of proposals for deep geological repositories (DGR's) for nuclear fuel wastes, CNSC conducted a research project to find out whether SOAR can be used by CNSC staff as an independent scoping tool to assist review of proponents' submissions related to safety assessment for DGRs. In the research, SOAR was applied to the post-closure safety assessment for a hypothetical DGR in sedimentary rock, as described in the 5th Case Study report by the Nuclear Waste Management Organization (NWMO) of Canada (2011). The report contains, among others, modeling of transport and releases of radionuclides at various locations within the geosphere and the radiation dose to humans over a period of one million years. One aspect covered was 1-D modeling of various scenarios and sensitivity cases with both deterministic and probabilistic approaches using SYVAC3-CC4, which stands for Systems Variability Analysis Code (generation 3, Canadian Concept generation 4), developed by Atomic Energy of Canada Limited (Kitson et al., 2000). Radionuclide fluxes and radiation dose to the humans calculated using SOAR were compared with that from NWMO's modeling. Overall, the results from the two models were similar, although SOAR gave lower mass fluxes and peak dose, mainly due to differences in modeling the waste package configurations. Sensitivity analyses indicate that both models are most sensitive to the diffusion coefficient of the geological media. The research leads to the conclusion that SOAR is a robust, user friendly, and flexible scoping tool that

  5. 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.

  6. 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. © 2014, National Ground Water Association.

  7. The impact of new data on an expert elicitation of the probability of volcanic intersection of the nuclear waste repository at Yucca Mountain

    NASA Astrophysics Data System (ADS)

    Perry, F. V.; Jenni, K. E.; Neiman, T.; Coppersmith, K.

    2008-12-01

    An expert elicitation completed in 1996 estimated the frequency of intersection by a dike of the proposed high-level radioactive waste repository at Yucca Mountain. That assessment resulted in a mean annual frequency of intersection of 1.7e -8, or about 1 chance in 60 million per year. The expert panel primarily considered the past 5 million years of volcanic history when estimating the probability of intersection, and included in their assessment the possibility that at least a few volcanic centers were buried in alluvial basins near Yucca Mountain. The results of a regional aeromagnetic survey completed in 1999 suggested the potential for a higher number of buried volcanic centers than previously considered in the 1996 elicitation. Therefore, a new expert elicitation was convened in 2004 with the primary purpose of assessing the impact of buried volcanic centers on probability estimates. A major data-gathering effort completed in 2006 provided high-resolution aeromagnetic, drilling, and geochronology results that provided information on the number, location and age of buried basaltic centers near Yucca Mountain. Most buried basalt was determined to be of Miocene age. The youngest group of buried volcanic centers, 20-25 km south of Yucca Mountain, has an age of about 3.9 Ma. These results indicate that post-Miocene basaltic volcanism only occurred to the south and west of Yucca Mountain and not to the east, an important constraint in models that forecast the potential location of future volcanism. Other new data considered included the characteristics of dike swarms based on analog volcanoes, variations in crustal extension across the region, mantle tomography, and differences in calculated lithostatic pressure between basins and ranges. The new distribution for the annual frequency of intersection (5th and 95th percentiles of ~6e -10 and 1e -7) overlaps the 1996 distribution but is broader with more weight at both higher and lower values. This results in a

  8. 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.

  9. 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.

  10. 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.

  11. Southern Nevada residents` views about the Yucca Mountain high-level nuclear waste repository and related issues: A comparative analysis of urban and rural survey data

    SciTech Connect

    Krannich, R.S.; Little, R.L.; Mushkatel, A.; Pijawka, K.D.; Jones, P.

    1991-10-01

    two separate surveys were undertaken in 1988 to ascertain southern Nevadans` views about the Yucca Mountain repository and related issues. The first of these studies focused on the attitudes and perceptions of residents in the Las Vegas metropolitan area. The second study addressed similar issues, but focused on the views of residents in six rural communities in three counties adjacent to the Yucca Mountain site. However, parallel findings from the two data sets have not been jointly analyzed in order to identify ways in which the views and orientations of residents in the rural and urban study areas may be similar or different. The purpose of this report is to develop and present a comparative assessment of selected issues addressed in the rural and urban surveys. Because both urban and rural populations would potentially be impacted by the Yucca Mountain repository, such an analysis will provide important insights into possible repository impacts on the well-being of residents throughout southern Nevada.

  12. 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

  13. 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.

  14. Progress in evaluation of radionuclide geochemical information developed by DOE high-level nuclear waste repository site projects: Report for April 1986--September 1987

    SciTech Connect

    Meyer, R.E.; Arnold, W.D.; Blencoe, J.G.; O`Kelley, G.D.; Land, J.F.

    1988-07-01

    During this report period, all experiments were conducted with tuff from the proposed high-level nuclear waste site at Yucca Mountain, Nevada. Batch sorption ratio determinations were conducted for strontium, cesium, uranium, and technetium onto samples of tuff using real and synthetic groundwater J-13. There were no significant differences in sorption ratios in experiments with real and synthetic groundwater. Columns were tested by determination of elution curves in J-13 containing tritium and technetium as the TcO{sub 4}/sup {minus}/ ion. For strontium and cesium, fairly good correlation between values of the sorption ratio obtained by the two methods was observed. Little technetium sorption was observed with either method. The elution peaks obtained with neptunium and uranium were asymmetrical and the shapes were often complex, observations which suggest irreversibilities in the sorption reaction. Synthetic groundwater J-13 was slowly dripped onto a slab of tuff maintained at 95--100{degree}C, and the result was a thin encrustation of solids on the slab as the water evaporated. Fresh J-13 groundwater was then allowed to contact the encrustation in a vessel maintained at 90{degree}C. The principal result of the experiment was a significant loss of calcium and magnesium from the fresh J-13 groundwater. 13 refs. 25 figs., 9 tabs.

  15. 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.

  16. Precipitation-Front Modeling: Issues Relating to Nucleation and Metastable Precipitation in the Planned Nuclear Waste Repository at Yucca Mountain, Nevada

    SciTech Connect

    Apps, J.A.; Sonnenthal, E.L.

    2004-04-01

    The focus of the presentation is on certain aspects concerning the kinetics of heterogeneous reactions involving the dissolution and precipitation of unstable and metastable phases under conditions departing from thermodynamic equilibrium. These aspects are particularly relevant to transient thermal-hydrological-chemical (THC) processes that will occur as a result of the emplacement of radioactive waste within the Yucca Mountain Repository. Most important of these is a phenomenon commonly observed in altering soils, sediments and rocks, where less stable minerals precipitate in preference to those that are more stable, referred to as the Ostwald Rule of Stages, or the Ostwald Step Rule. W. Ostwald (1897) described the phenomenon characterizing his rule (as cited in Schmeltzer et al., 1998), thus: ''...in the course of transformation of an unstable (or metastable) state into a stable one the system does not go directly to the most stable conformation (corresponding to the modification with the lowest free energy) but prefers to reach intermediate stages (corresponding to other metastable modifications) having the closest free energy to the initial state''. This phenomenon is so widespread in natural geochemical systems, particularly under hydrothermal or low temperature conditions, that few geochemical parageneses involving the subcritical aqueous phase can be described without invoking the Ostwald Rule of Stages. Commonly observed systems where this phenomenon occurs include carbonates, silica, clay minerals, iron and manganese oxides, iron sulfides and zeolites (Morse and Casey, 1988). Simulations involving natural or anthropogenically modified reactive chemical transport must therefore be consistent with field observations describable by the Ostwald Rule. Geochemists have long been familiar with the Ostwald Rule, but, with one exception (Steefel and Van Cappellen, 1990), have not incorporated the underlying chemical principles justifying the Rule in reactive

  17. Evaluation of Incident Risks in a Repository for Radioactive Waste

    SciTech Connect

    Grundler, D.; Mariae, D.; Muller, W.; Boetsch, W.; Thiel, J.

    2008-07-01

    A probabilistic safety assessment of the operation phase of a repository for radioactive waste requires the knowledge of incident risks. These are evaluated from generic observations. The present method accounts for the uncertainty (1) of whether an incident occurs, (2) of the incident rate, (3) of the duration of generic observation, and (4) of the duration of operation phase of the repository. It yields a mean risk and its standard deviation from a minimum of generic data, comprising only the number of observed incidents and the duration of the observation, as more comprehensive generic data are seldom available. It was shown that incidents sharing a common generic observation must be either merged together to a total incident or the generic observation must be split up in sub-observations, one for each such incident. The method was tested on the example of the German Konrad repository for low-level waste in a deep geological formation. (authors)

  18. 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.

  19. 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

    NA

    2001-02-15

    The Yucca Mountain Draft Environmental Impact Statement (DEIS) analysis addressed the potential for transporting spent nuclear fuel and high-level radioactive waste from 77 origins for 34 types of spent fuel and high-level radioactive waste, 49,914 legal weight truck shipments, and 10,911 rail shipments. The analysis evaluated transportation over 59,250 unique shipment links for travel outside Nevada (shipment segments in urban, suburban or rural zones by state), and 22,611 links in Nevada. In addition, the analysis modeled the behavior of 41 isotopes, 1091 source terms, and used 8850 food transfer factors (distinct factors by isotope for each state). The analysis also used mode-specific accident rates for legal weight truck, rail, and heavy haul truck by state, and barge by waterway. This complex mix of data and information required an innovative approach to assess the transportation impacts. The approach employed a Microsoft{reg_sign} Access database tool that incorporated data from many sources, including unit risk factors calculated using the RADTRAN IV transportation risk assessment computer program. Using Microsoft{reg_sign} Access, the analysts organized data (such as state-specific accident and fatality rates) into tables and developed queries to obtain the overall transportation impacts. Queries are instructions to the database describing how to use data contained in the database tables. While a query might be applied to thousands of table entries, there is only one sequence of queries that is used to calculate a particular transportation impact. For example, the incident-free dose to off-link populations in a state is calculated by a query that uses route segment lengths for each route in a state that could be used by shipments, populations for each segment, number of shipments on each segment, and an incident-free unit risk factor calculated using RADTRAN IV. In addition to providing a method for using large volumes of data in the calculations, the

  20. Permanent Disposal of Nuclear Waste in Salt

    NASA Astrophysics Data System (ADS)

    Hansen, F. D.

    2016-12-01

    Salt formations hold promise for eternal removal of nuclear waste from our biosphere. Germany and the United States have ample salt formations for this purpose, ranging from flat-bedded formations to geologically mature dome structures. Both nations are revisiting nuclear waste disposal options, accompanied by extensive collaboration on applied salt repository research, design, and operation. Salt formations provide isolation while geotechnical barriers reestablish impermeability after waste is placed in the geology. Between excavation and closure, physical, mechanical, thermal, chemical, and hydrological processes ensue. Salt response over a range of stress and temperature has been characterized for decades. Research practices employ refined test techniques and controls, which improve parameter assessment for features of the constitutive models. Extraordinary computational capabilities require exacting understanding of laboratory measurements and objective interpretation of modeling results. A repository for heat-generative nuclear waste provides an engineering challenge beyond common experience. Long-term evolution of the underground setting is precluded from direct observation or measurement. Therefore, analogues and modeling predictions are necessary to establish enduring safety functions. A strong case for granular salt reconsolidation and a focused research agenda support salt repository concepts that include safety-by-design. 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 National Nuclear Security Administration under contract DE-AC04-94AL85000. Author: F. D. Hansen, Sandia National Laboratories

  1. 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

  2. Insights to repository performance through study of a nuclear test site

    SciTech Connect

    Smith, D K; Kersting, A B; Thompson, J L; Finnegan, D L

    2000-07-12

    Underground nuclear test sites offer an unprecedented opportunity to evaluate processes relevant to high-level waste repository performance in the absence of engineered barriers. Radionuclide migration programs at the Nevada Test Site represent a twenty-five year systematic investigation of the diverse radiologic source terms residual from weapons testing and the evolution of the hydrologic source term which comprises those radionuclides dissolved in or otherwise available for transport by groundwater. The Nevada Test Site shares actinide source terms, correlative geology, an identical tectonic setting, similar climate, and a thick unsaturated zone with the adjacent proposed Yucca Mountain high-level waste repository and provides a natural laboratory to assess long-term radionuclide transport in the near field. Analog studies may ultimately help validate predictions of radionuclide transport from the Yucca Mountain repository.

  3. 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.

  4. 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.

  5. 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.

    1988-12-01

    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. 91 refs., 14 figs., 15 tabs.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Alternative waste package designs and storage concepts for disposal of high level wastes at the Yucca Mountain Repository

    NASA Astrophysics Data System (ADS)

    Kar, Piyush

    This dissertation presents and analyzes alternative waste package (WP) designs and operating concept for the Yucca Mountain repository. A 2 nd generation WP design as well as an operating concept are introduced to reduce the risk of corrosion and to lower the repository costs. The concept permits major reductions in repository costs by increasing the WP thermal loading, by eliminating the need for titanium drip shields and by fabricating the outer container from corrosion resistant low alloy carbon steel. The 2 nd generation concept utilizes the benefits of hot dry storage to minimize the potential for corrosion of the WP by liquid electrolytes. On similar lines to the second generation WP design and operating concept, four different WP designs are introduced for the PWR and BWR WPs that support the perspective of a generally drier emplacement drift due to increase in heat load and resulting higher temperatures. The designs are modifications of current US Department of Energy WPs. Nuclear waste was configured in the Cartesian as well as the radial manner with and without increase in the overall size of the WPs. The alternative designs would help cutting down nuclear waste disposal cost without sacrificing the containment standards. WP internal thermal analysis was performed for all the configurations types to demonstrate safety of the designs in terms of maximum attainable temperatures. The thermal analysis addresses heat transfer issues inside the waste packages.

  11. 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)

  12. 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.

  13. Progress in site selection for China`s high-level radioactive waste repository

    SciTech Connect

    Xu, G.; Wang, J.; Jin, Y.; Chen, W.

    1995-12-31

    In 1985, the China National Nuclear Corporation (CNNC) worked out an R and D program called DG program for the deep geological disposal of high-level radioactive waste in China. The site selection process for China`s HLW repository has been carried out since then according to this program. Granite is considered as the candidate host rock for the repository. The general siting criteria are based on the principle that, under the effect of natural and human activities, the long term (100,000 years) safety of the repository can be reasonably obtained and the disposed radioactive waste can be avoided from entering the biosphere and harming human beings. During siting, two types of factors are considered: (1) social factors, including the nuclear industry distribution population, economic potential and environmental protection etc.; (2) natural factors, including geographic, meteorological and geological (crustal stability, host rocks, hydrogeology, engineering geology). The site selection process is divided into 4 stages: (1) nationwide screening, (2) regional screening; (3) district screening; and (4) site screening. During the first stage (1985--1986) the following were considered as potential regions: (1) southwest China, (2) Guangdong area, (3) Inner Mongolia, (4) east China and (5) northwest China. During the second stage (1986--1988), 21 districts were selected for further investigation. Since 1989 most efforts have been focused on the Beishan area, Gansu province, northwest China, which is considered as the most potential district for the repository.

  14. Enlargement of the Baldone near-surface radioactive waste repository

    SciTech Connect

    Dreimanis, A.

    2007-07-01

    A unified analysis of the enlargement of the Baldone near-surface radioactive waste (RW) repository RADONS considers the interplay of the existing engineering, safety and infrastructure premises, with the foreseen newly socio-technical features. This enlargement consists in construction of two additional RW disposal vaults and in building a long-term storage facility for spent sealed sources at the RADONS territory. Our approach is based on consecutive analysis of following basic elements: - the origin of enlargement - the RADONS safety analysis and a set of optimal socio-technical solutions of Salaspils research reactor decommissioning waste management; - the enlargement - a keystone of the national RW management concept, including the long-term approach; - the enlargement concept - the result of international co-operation and obligations; - arrangement optimization of new disposal and storage space; - environmental impact assessment for the repository enlargement - the update of socio-technical studies. The study of the public opinion revealed: negative attitude to repository enlargement is caused mainly due to missing information on radiation level and on the RADONS previous operations. These results indicate: basic measures to improve the public attitude to repository enlargement: the safety upgrade, public education and compensation mechanisms. A detailed stakeholders engagement and public education plan is elaborated. (author)

  15. 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.

  16. Nuclear Waste Fund fee adequacy: An assessment

    SciTech Connect

    1990-11-01

    The purpose of this report is to present the Department of Energy`s (the Department) analysis of the adequacy of the 1.00 mill per kilowatt-hour (kWh) fee being paid by the utilities generating nuclear power for the permanent disposal of their spent nuclear fuel (SNF). In accordance with the Nuclear Waste Policy Act (NWPA), the SNF would be disposed of in a geologic repository to be developed by the Department. An annual analysis of the fee`s adequacy is required by the NWPA.

  17. 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)

  18. 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)

  19. 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.

  20. 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]."

  1. 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.

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

    SciTech Connect

    Forsberg, Charles W.

    1997-12-01

    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 isotonically-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.

  3. 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.

  4. Nuclear characteristics of vitrified high-level waste at the West Valley Demonstration Project

    SciTech Connect

    Arakali, V.S.; Barnes, S.M. )

    1991-11-01

    High-level liquid nuclear waste stored in underground tanks at West Valley, New York, will be vitrified as borosilicate glass and stored in stainless steel canisters prior to disposal at a waste repository. The nuclear characteristics of the vitrified waste must meet certain repository design specifications. This paper presents an evaluation of the waste form produced at West Valley with respect to its compliance to the repository specifications of heat and gas generation rates and neutron and gamma dose rates. The method consists of analyzing the composition of liquid nuclear waste in underground tanks and estimating the amount of other chemicals needed to encapsulate radionuclides in glass matrices. The number of waste canisters and the composition of each batch of canistered waste are determined from the vitrification process flow sheet. This data is used in computer codes to evaluate the waste form against repository specifications.

  5. 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.

  6. 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%.

  7. Radiation Effects in a Model Ceramic for Nuclear Waste Disposal

    SciTech Connect

    Devanathan, Ram; Weber, William J.

    2007-04-02

    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. In this paper, we discuss the atomistic details of radiation damage in a model ceramic, zircon.

  8. 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.

  9. New Design for an HLW Repository (for Spent Fuel and Waste from Reprocessing) in a Salt Formation in Germany - 12213

    SciTech Connect

    Bollingerfehr, Wilhelm; Filbert, Wolfgang; Lerch, Christian; Mueller-Hoeppe, Nina; Charlier, Frank

    2012-07-01

    In autumn 2010, after a 10-year moratorium, exploration was resumed in Gorleben, the potential site for a German HLW repository. At the same time, the Federal Government launched a two-year preliminary safety analysis to assess whether the salt dome at Gorleben is suitable to host all heat-generating radioactive waste generated by German NPPs based on the waste amounts expected at that time. The revised Atomic Energy Act of June 2011 now stipulates a gradual phase-out of nuclear energy production by 2022, which is 13 years earlier than expected in 2010. A repository design was developed which took into account an updated set of data on the amounts and types of expected heat-generating waste, the documented results of the exploration of the Gorleben salt dome, and the new 'Safety Requirements Governing the Final Disposal of Heat-Generating Radioactive Waste' of 30 September, 2010. The latter has a strong influence on the conceptual designs as it requires that retrievability of all waste containers is possible within the repository lifetime. One design considered that all waste containers will be disposed of in horizontal drifts of a geologic repository, while the other design considered that all waste containers will be disposed of in deep vertical boreholes. For both options (emplacement in drifts/emplacement in vertical boreholes), the respective design includes a selection of waste containers, the layout of drifts, respectively lined boreholes, a description of emplacement fields, and backfilling and sealing measures. The design results were described and displayed and the differences between the two main concepts were elaborated and discussed. For the first time in both repository designs the requirement was implemented to retrieve waste canisters during the operational phase. The measures to fulfill this requirement and eventually the consequences were highlighted. It was pointed out that there arises the need to keep transport- and storage casks in adequate

  10. Devising a groundwater monitoring strategy for a geologic repository for radioactive waste

    NASA Astrophysics Data System (ADS)

    Leonhart, L. S.; Deluca, F. A.; Sheahan, N. T.; West, L. M.

    A topical treatment of the subject of groundwater monitoring as it relates to the particular needs of high-level nuclear waste disposal facilities using the Basalt Waste Isolation Project (BWIP) as a specific reference is presented. While the involvement with management of high-level radioactive wastes and the design and operation of repository facilities is presently parochial to the federal government and certain prime contractors, it is believed that the technical aspects involved with this groundwater monitoring example provide an interesting comparison with those encountered at near-surface and underground-injection, hazardous waste disposal operations. In particular, the integration of several program facets ranging from baselining parameters to validation of predictive models into a comprehensive strategy may be of interest. It is hoped that this type of conceptual exchange will be beneficial to all concerned.

  11. Simulated geophysical monitoring of radioactive waste repository barriers

    NASA Astrophysics Data System (ADS)

    Biryukov, Anton

    Estimation of attenuation of the elastic waves in clays and high clay-content rocks is important for the quality of geophysical methods relying on processing the recorded waveforms. Time-lapse imaging is planned to be employed for monitoring of the condition of high-radioactive waste repositories. Engineers can analyze and optimize configuration of the monitoring system using numerical modelling tools. The reliability of modeling requires proper calibration. The purpose of this thesis is threefold: (i) propose a calibration methodology for the wave propagation tools based on the experimental data, (ii) estimate the attenuation in bentonite as a function of temperature and water content, and (iii) investigate the feasibility of active sonic monitoring of the engineered barriers. The results suggest that pronounced inelastic behavior of bentonite has to be taken into account in geophysical modeling and analysis. The repository--scale models confirm that active sonic monitoring is capable of depicting physical changes in the bentonite barrier.

  12. 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…

  13. Evaluation of a potential nuclear fuel repository criticality: Lessons learned

    SciTech Connect

    Wilson, J.R.; Evans, D.

    1995-10-01

    This paper presents lessons learned from a Probabilistic Risk Assessment (PRA) of the potential for a criticality in a repository containing spent nuclear fuel with high enriched uranium. The insights gained consisted of remarkably detailed conclusions about design issues, failure mechanisms, frequencies and source terms for events up to 10,000 years in the future. Also discussed are the approaches taken by the analysts in presenting this very technical report to a nontechnical and possibly antagonistic audience.

  14. 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.

  15. 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

  16. Magma flow and interaction with waste packages in a geologic repository at Yucca Mountain, Nevada

    NASA Astrophysics Data System (ADS)

    Marsh, Bruce D.; Coleman, Neil M.

    2009-05-01

    The likelihood that a nuclear waste repository at Yucca Mountain could be intersected by igneous activity is very low, but its potential consequences are nevertheless important to performance assessments. An ongoing critical area of concern is the nature and magnitude of the thermal interaction of magma with tunnel walls, high-level nuclear waste packages, and waste forms. Previous assessments consider a variety of dynamic scenarios, but large uncertainties remain in understanding the rheological nature of the magma likely to be involved and its behavior within a repository drift. Here we specifically address the issue of magma rheology during degassing, cooling, and solidification as basaltic magma approaches Earth's surface and enters a drift. Magma containing significant amounts (> ~ 2 wt.%) of dissolved water (Wet Magma), as is anticipated for this region, at or near its liquidus temperature and saturated with water at 200 MPa is at a temperature near or below the 1-atm solidus temperature. Isentropic ascent from this near liquidus temperature promotes extensive solidification and/or glassification. Exsolving water with approach to the surface promotes rapid vesiculation leading to fragmentation and tephra production. With continued ascent the still water-saturated magma traverses the solidification phase field and undergoes a combination of rapid crystallization and quenching, becoming a glassy highly viscous (~ 10 8 Pa s) mass of greatly reduced mobility. This immobility is reflected in the high effective viscosity regulating flows from nearby cinder cones associated with wet basalt. This also matches well with the experimentally determined rheology of dry basalt glass. This rheology greatly restricts the mobility of basalt within repository drifts, amounting to < 10 m per day. Magma in this state quenches rapidly (~ 10 cm/min) on waste packages. Wet basalt is explosive, but relatively immobile as lava. Dry Magma is not explosive, but highly mobile as lava

  17. 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.

  18. 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

  19. Nuclear waste management: a perspective

    SciTech Connect

    Leuze, R.E.

    1980-01-01

    The scope of our problems with nuclear waste management is outlined. Present and future inventories of nuclear wastes are assessed for risk. A discussion of what is presently being done to solve waste management problems and what might be done in the future are presented. (DC)

  20. 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.

  1. 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.

  2. 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.

  3. Hazards of managing and disposing of nuclear waste

    SciTech Connect

    Kastenberg, W.E.; Gratton, L.J.

    1997-06-01

    When we bury long-lived nuclear wastes in geologic repositories, we have to worry about what may happen ten thousand{emdash}or even a million{emdash}years in the future.{copyright} {ital 1997 American Institute of Physics.}

  4. Public acceptance and real testing of a nuclear repository

    SciTech Connect

    Brotzen, O.

    1995-12-31

    A local referendum and national polls show predominant distrust of the current disposal concept for spent nuclear fuel in Sweden. Plain neglect of in-place testing and monitoring of repository performance may be a contributing factor. The long periods of time involved in safe disposal call for thorough study of the potential and limitations of accelerated tests. The variation in some time involved in safe disposal call for thorough study of the potential and limitations of accelerated tests. The variation in some rate-determining factors attainable in an open repository suggests that results may be obtained which after backfilling would need periods of time comparable to those required for decay of the most harmful, strongly sorbed radionuclides. Focus should be on the isolation and containment of radionuclides in the accessible nearfield, rather than on nuclide release and transport through the inaccessible farfield. Tentative approaches are outlined, regarding nearfield groundwater control and barrier performance, and the local geochemical record, for decisions before excavations start, before development of disposal areas in a repository, and before emplacement of spent fuel, and also for monitoring performance thereafter. All tests should provide input to a strict and public licensing procedure, which ensures that no phase in disposal can be seen as a point of no return endangering future generations.

  5. Nuclear Waste Management - A Need to Ensure that the Waste Decays While the Knowledge Does Not

    SciTech Connect

    Biedscheid, J.; Devarakonda, M.

    2006-07-01

    The unique time scales associated with nuclear waste management require active work to preserve the knowledge associated with programs that can often span long time frames. For example, repository programs are designed and developed for the safe containment of radionuclides with half-lives on the order of 24,000 years (for Pu-239). Performance assessment studies are required to show, by predictive modeling, that these repositories can safely contain the waste for tens of thousands of years, with one million years a reality in the debate. Development of successful repository programs can span several decades. Once operational, a repository is expected to function until closure for a period of 30 to 40 years. Yet, the decision makers at all levels in such a repository program exert influence and authority over much shorter periods of time (e.g., four years for executive appointments). A discontinuous decision-making process and the associated potential for loss of critical program knowledge are challenges that nuclear waste management programs face in various countries. Due to the disparity of the time frames for the project and associated decision-making, a proactive program to preserve original and developing knowledge for technical and programmatic decisions is vital to the success of any nuclear waste management program. While the mechanisms for knowledge preservation may be program specific, the need for programs to acknowledge and implement a methodology for maintaining program intelligence is collectively shared. (authors)

  6. 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.

  7. 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.

  8. 76 FR 3678 - Board Meeting: February 16, 2011-Las Vegas, NV, the U.S. Nuclear Waste Technical Review Board...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-20

    ... Radioactive Waste Pursuant to its authority under section 5051 of Public Law 100-203, Nuclear Waste Policy...) activities related to managing and disposing of spent nuclear fuel and high-level radioactive waste. The... repository for spent fuel and high-level radioactive waste over the last two decades. The Board also will...

  9. Numerical Modeling of Thermal-Hydrology in the Near Field of a Generic High-Level Waste Repository

    NASA Astrophysics Data System (ADS)

    Matteo, E. N.; Hadgu, T.; Park, H.

    2016-12-01

    Disposal in a deep geologic repository is one of the preferred option for long term isolation of high-level nuclear waste. Coupled thermal-hydrologic processes induced by decay heat from the radioactive waste may impact fluid flow and the associated migration of radionuclides. This study looked at the effects of those processes in simulations of thermal-hydrology for the emplacement of U. S. Department of Energy managed high-level waste and spent nuclear fuel. Most of the high-level waste sources have lower thermal output which would reduce the impact of thermal propagation. In order to quantify the thermal limits this study concentrated on the higher thermal output sources and on spent nuclear fuel. The study assumed a generic nuclear waste repository at 500 m depth. For the modeling a representative domain was selected representing a portion of the repository layout in order to conduct a detailed thermal analysis. A highly refined unstructured mesh was utilized with refinements near heat sources and at intersections of different materials. Simulations looked at different values for properties of components of the engineered barrier system (i.e. buffer, disturbed rock zone and the host rock). The simulations also looked at the effects of different durations of surface aging of the waste to reduce thermal perturbations. The PFLOTRAN code (Hammond et al., 2014) was used for the simulations. Modeling results for the different options are reported and include temperature and fluid flow profiles in the near field at different simulation times. References:G. E. Hammond, P.C. Lichtner and R.T. Mills, "Evaluating the Performance of Parallel Subsurface Simulators: An Illustrative Example with PFLOTRAN", Water Resources Research, 50, doi:10.1002/2012WR013483 (2014). Sandia National Laboratories 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

  10. 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.

  11. 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)

  12. 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)

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Nuclear-waste disposal: Technical issues and status

    NASA Astrophysics Data System (ADS)

    Hunter, T. O.

    The nuclear waste from the defense programs of the United States and the commercial nuclear fuel cycle are planned for disposal in mined geologic repositories. High-level waste will require the development of one to three repositories. A number of technical issues are associated with the selection and characterization of a suitable site, the design of surface and underground facilities, development of an appropriate waste package, and methods to assess the performance of the system relative to regulatory requirements. These issues are being addressed by four major projects to evaluate salt, basalt, volcanic tuff, and other crystalline rocks such as granite. The key technical issues and the status of activities to resolve those issues are reviewed.

  1. Preliminary safety evaluation of an aircraft impact on a near-surface radioactive waste repository

    SciTech Connect

    Lo Frano, R.; Forasassi, G.; Pugliese, G.

    2013-07-01

    The aircraft impact accident has become very significant in the design of a nuclear facilities, particularly, after the tragic September 2001 event, that raised the public concern about the potential damaging effects that the impact of a large civilian airplane could bring in safety relevant structures. The aim of this study is therefore to preliminarily evaluate the global response and the structural effects induced by the impact of a military or commercial airplane (actually considered as a 'beyond design basis' event) into a near surface radioactive waste (RWs) disposal facility. The safety evaluation was carried out according to the International safety and design guidelines and in agreement with the stress tests requirements for the security track. To achieve the purpose, a lay out and a scheme of a possible near surface repository, like for example those of the El Cabril one, were taken into account. In order to preliminarily perform a reliable analysis of such a large-scale structure and to determine the structural effects induced by such a types of impulsive loads, a realistic, but still operable, numerical model with suitable materials characteristics was implemented by means of FEM codes. In the carried out structural analyses, the RWs repository was considered a 'robust' target, due to its thicker walls and main constitutive materials (steel and reinforced concrete). In addition to adequately represent the dynamic response of repository under crashing, relevant physical phenomena (i.e. penetration, spalling, etc.) were simulated and analysed. The preliminary assessment of the effects induced by the dynamic/impulsive loads allowed generally to verify the residual strength capability of the repository considered. The obtained preliminary results highlighted a remarkable potential to withstand the impact of military/large commercial aircraft, even in presence of ongoing concrete progressive failure (some penetration and spalling of the concrete wall) of the

  2. Irradiated Nuclear Fuel Management: Resource Versus Waste

    SciTech Connect

    Nash, Kenneth L.; Lumetta, Gregg J.; Vienna, John D.

    2013-01-01

    Management of irradiated fuel is an important component of commercial nuclear power production. Although it is broadly agreed that the disposition of some fraction of the fuel in geological repositories will be necessary, there is a range of options that can be considered that affect exactly what fraction of material will be disposed in that manner. Furthermore, until geological repositories are available to accept commercial irradiated fuel, these materials must be safely stored. Temporary storage of irradiated fuel has traditionally been conducted in storage pools, and this is still true for freshly discharged fuel. Criticality control technologies have led to greater efficiencies in packing of irradiated fuel into storage pools. With continued delays in establishing permanent repositories, utilities have begun to move some of the irradiated fuel inventory into dry storage. Fuel cycle options being considered worldwide include the once-through fuel cycle, limited recycle in which U and Pu are recycled back to power reactors as mixed oxide fuel, and advance partitioning and transmutation schemes designed to reduce the long term hazards associated with geological disposal from millions of years to a few hundred years. Each of these options introduces specific challenges in terms of the waste forms required to safely immobilize the hazardous components of irradiated fuel.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. Prediction of contaminant migration around radioactive waste repositories in salt formations in Germany

    SciTech Connect

    Wollrath, J.

    1995-12-31

    With rock salt as host formation of a radioactive waste repository density effects on the groundwater movement have to be considered. Therefore, the assumptions, results and difficulties of modelling groundwater movement and taking into account density effects are presented and discussed with reference to the calculations performed for the Gorleben repository. The results are compared to results obtained in the safety analyses for the Konrad repository. It is shown that the consideration of variable groundwater density increases groundwater travel times and hence slows down the transport of contaminants from the repository location to the ground surface.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. Thermal–hydraulic–mechanical modeling of a large-scale heater test to investigate rock salt and crushed salt behavior under repository conditions for heat-generating nuclear waste

    DOE PAGES

    Blanco-Martín, Laura; Wolters, Ralf; Rutqvist, Jonny; ...

    2016-04-28

    The Thermal Simulation for Drift Emplacement heater test is modeled with two simulators for coupled thermal-hydraulic-mechanical processes. Results from the two simulators are in very good agreement. The comparison between measurements and numerical results is also very satisfactory, regarding temperature, drift closure and rock deformation. Concerning backfill compaction, a parameter calibration through inverse modeling was performed due to insufficient data on crushed salt reconsolidation, particularly at high temperatures. We conclude that the two simulators investigated have the capabilities to reproduce the data available, which increases confidence in their use to reliably investigate disposal of heat-generating nuclear waste in saliferous geosystems.

  15. 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)

  16. Salt Disposal Investigations to Study Thermally Hot Radioactive Waste In A Deep Geologic Repository in Bedded Rock Salt - 12488

    SciTech Connect

    Nelson, Roger A.; Buschman, Nancy

    2012-07-01

    A research program is proposed to investigate the behavior of salt when subjected to thermal loads like those that would be present in a high-level waste repository. This research would build upon results of decades of previous salt repository program efforts in the US and Germany and the successful licensing and operation of a repository in salt for disposal of defense transuranic waste. The proposal includes a combination of laboratory-scale investigations, numerical simulations conducted to develop validated models that could be used for future repository design and safety case development, and a thermal field test in an underground salt formation with a configuration that replicates a small portion of a conceptual repository design. Laboratory tests are proposed to measure salt and brine properties across and beyond the range of possible repository conditions. Coupled numerical models will seek to describe phenomenology (thermal, mechanical, and hydrological) observed in the laboratory tests. Finally, the field test will investigate many phenomena that have been variously cited as potential issues for disposal of thermally hot waste in salt, including buoyancy effects and migration of pre-existing trapped brine up the thermal gradient (including vapor phase migration). These studies are proposed to be coordinated and managed by the Carlsbad Field Office of DOE, which is also responsible for the operation of the Waste Isolation Pilot Plant (WIPP) within the Office of Environmental Management. The field test portion of the proposed research would be conducted in experimental areas of the WIPP underground, far from disposal operations. It is believed that such tests may be accomplished using the existing infrastructure of the WIPP repository at a lower cost than if such research were conducted at a commercial salt mine at another location. The phased field test is proposed to be performed over almost a decade, including instrumentation development, several years

  17. Public attitudes about nuclear waste

    SciTech Connect

    Bisconti, A.S.

    1991-12-01

    There is general agreement that nuclear waste is an important national issue. It certainly is important to the industry. congress, too, gives high priority to nuclear waste disposal. In a recent pool by Reichman, Karten, Sword, 300 congressional staffers named nuclear waste disposal as the top nuclear energy-related legislative issue for Congress to address. In this paper most of the data the author discusses are from national polls that statistically represent the opinions of all American adults all across the country, as well as polls conducted in Nevada that statistically represent the opinions of all adults in that state. All the polls were by Cambridge Reports and have a margin of error of {plus_minus} 3%.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Waste package for Yucca Mountain repository: Strategy for regulatory compliance

    SciTech Connect

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

    1989-02-01

    This document summarizes the strategy given in the Site Characterization Plan (1) 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. 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. In implementing the strategy, DOE recognizes four fundamental goals: (1) protect public health and safety; (2) minimize financial and other resource commitments; (3) comply with applicable laws and regulations; and (4) maintain an aggressive schedule. The strategy is intended to be a reasonable balance of these competing goals. 7 refs., 3 figs., 1 tab.

  4. Initial demonstration of the NRC`s capability to conduct a performance assessment for a High-Level Waste Repository

    SciTech Connect

    Codell, R.; Eisenberg, N.; Fehringer, D.; Ford, W.; Margulies, T.; McCartin, T.; Park, J.; Randall, J.

    1992-05-01

    In order to better review licensing submittals for a High-Level Waste Repository, the US Nuclear Regulatory Commission staff has expanded and improved its capability to conduct performance assessments. This report documents an initial demonstration of this capability. The demonstration made use of the limited data from Yucca Mountain, Nevada to investigate a small set of scenario classes. Models of release and transport of radionuclides from a repository via the groundwater and direct release pathways provided preliminary estimates of releases to the accessible environment for a 10,000 year simulation time. Latin hypercube sampling of input parameters was used to express results as distributions and to investigate model sensitivities. This methodology demonstration should not be interpreted as an estimate of performance of the proposed repository at Yucca Mountain, Nevada. By expanding and developing the NRC staff capability to conduct such analyses, NRC would be better able to conduct an independent technical review of the US Department of Energy (DOE) licensing submittals for a high-level waste (HLW) repository. These activities were divided initially into Phase 1 and Phase 2 activities. Additional phases may follow as part of a program of iterative performance assessment at the NRC. The NRC staff conducted Phase 1 activities primarily in CY 1989 with minimal participation from NRC contractors. The Phase 2 activities were to involve NRC contractors actively and to provide for the transfer of technology. The Phase 2 activities are scheduled to start in CY 1990, to allow Sandia National Laboratories to complete development and transfer of computer codes and the Center for Nuclear Waste Regulatory Analyses (CNWRA) to be in a position to assist in the acquisition of the codes.

  5. 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

  6. 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.

  7. Geological Repository Layout for Radioactive High Level Long Lived Waste in Argilite

    SciTech Connect

    Gaussen, J.L.

    2006-07-01

    In the framework of the 1991 French radioactive waste act, ANDRA has studied the feasibility of a geological repository in the argillite layer of the Bure site for high-level long-lived waste. This presentation is focused on the underground facilities that constitute the specific component of this project. The preliminary underground layout, which has been elaborated, is based on four categories of data: - the waste characteristics and inventory; - the geological properties of the host argillite; - the long term performance objectives of the repository; - the specifications in term of operation and reversibility. The underground facilities consist of two types of works: the access works (shafts and drifts) and the disposal cells. The function of the access works is to permit the implementation of two concurrent activities: the nuclear operations (transfer and emplacement of the disposal packages into the disposal cells) and the construction of the next disposal cells. The design of the drifts network which matches up to this function is also influenced by two other specifications: the minimisation of the drift dimensions in order to limit their influence on the integrity of the geological formation and the necessity of a safe ventilation in case of fire. The resulting layout is a network of 4 parallel drifts (2 of them being dedicated to the operation, the other two being dedicated to the construction activities). The average diameter of these access drifts is 7 meters. 4 shafts ensure the link between the surface and the underground. The most important function of the disposal cells is to contribute to the long-term performance of the repository. In this regard, the thermal and geotechnical considerations play an important role. The B wastes (intermediate level wastes) are not (or not very) exothermic. Consequently, the design of their disposal cells result mainly from geotechnical considerations. The disposal packages (made of concrete) are piled up in big

  8. 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.

  9. 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.

  10. 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)

  11. 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)

  12. 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.

  13. 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.

  14. 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.

  15. 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)

  16. 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)

  17. The USNRC's Final Regulations for Disposal of High-Level Radioactive Wastes in a Potential Geologic Repository at Yucca Mountain

    SciTech Connect

    McCartin, T.; Kotra, J.; Pohle, J.; Wittmeyer, G.

    2002-02-27

    On February 22, 1999, the U.S. Nuclear Regulatory Commission (NRC) proposed licensing criteria in a new, separate part of its regulations, at 10 CFR Part 63 (hereafter referred to as Part 63), for disposal of high-level radioactive waste (HLW) in a potential geologic repository at Yucca Mountain, Nevada (1). After publication of the proposed Part 63, the staff provided members of the public and other stakeholders multiple opportunities to discuss the proposed requirements. On June 13, 2001, the U.S. Environmental Protection Agency (EPA) issued final environmental standards for a potential geologic repository at Yucca Mountain, Nevada at 40 CFR Part 197 (2), as mandated by the Energy Policy Act of 1992 (EnPA)(3). The NRC has prepared its final regulations based on careful review and consideration of the public comments received on its proposed rule and the statutory direction for NRC to adopt technical criteria consistent with final EPA standards.

  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. 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.

  20. 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.

  1. 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.

  2. Effects of Heat Generation on Nuclear Waste Disposal in Salt

    NASA Astrophysics Data System (ADS)

    Clayton, D. J.

    2008-12-01

    Disposal of nuclear waste in salt is an established technology, as evidenced by the successful operations of the Waste Isolation Pilot Plant (WIPP) since 1999. The WIPP is located in bedded salt in southeastern New Mexico and is a deep underground facility for transuranic (TRU) nuclear waste disposal. There are many advantages for placing radioactive wastes in a geologic bedded-salt environment. One desirable mechanical characteristic of salt is that it flows plastically with time ("creeps"). The rate of salt creep is a strong function of temperature and stress differences. Higher temperatures and deviatoric stresses increase the creep rate. As the salt creeps, induced fractures may be closed and eventually healed, which then effectively seals the waste in place. With a backfill of crushed salt emplaced around the waste, the salt creep can cause the crushed salt to reconsolidate and heal to a state similar to intact salt, serving as an efficient seal. Experiments in the WIPP were conducted to investigate the effects of heat generation on the important phenomena and processes in and around the repository (Munson et al. 1987; 1990; 1992a; 1992b). Brine migration towards the heaters was induced from the thermal gradient, while salt creep rates showed an exponential dependence on temperature. The project "Backfill and Material Behavior in Underground Salt Repositories, Phase II" (BAMBUS II) studied the crushed salt backfill and material behavior with heat generation at the Asse mine located near Remlingen, Germany (Bechthold et al. 2004). Increased salt creep rates and significant reconsolidation of the crushed salt were observed at the termination of the experiment. Using the data provided from both projects, exploratory modeling of the thermal-mechanical response of salt has been conducted with varying thermal loading and waste spacing. Increased thermal loading and decreased waste spacing drive the system to higher temperatures, while both factors are desired to

  3. 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.

  4. 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.

  5. Anticipating Potential Waste Acceptance Criteria for Defense Spent Nuclear Fuel

    SciTech Connect

    Rechard, R.P.; Lord, M.E.; Stockman, C.T.; McCurley, R.D.

    1997-12-31

    The Office of Environmental Management of the U.S. Department of Energy is responsible for the safe management and disposal of DOE owned defense spent nuclear fuel and high level waste (DSNF/DHLW). A desirable option, direct disposal of the waste in the potential repository at Yucca Mountain, depends on the final waste acceptance criteria, which will be set by DOE`s Office of Civilian Radioactive Waste Management (OCRWM). However, evolving regulations make it difficult to determine what the final acceptance criteria will be. A method of anticipating waste acceptance criteria is to gain an understanding of the DOE owned waste types and their behavior in a disposal system through a performance assessment and contrast such behavior with characteristics of commercial spent fuel. Preliminary results from such an analysis indicate that releases of 99Tc and 237Np from commercial spent fuel exceed those of the DSNF/DHLW; thus, if commercial spent fuel can meet the waste acceptance criteria, then DSNF can also meet the criteria. In large part, these results are caused by the small percentage of total activity of the DSNF in the repository (1.5%) and regulatory mass (4%), and also because commercial fuel cladding was assumed to provide no protection.

  6. 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.

  7. 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.

  8. Case histories of EA documents for nuclear waste

    SciTech Connect

    Vocke, R.W.

    1985-01-01

    Nuclear power programs and policies in the United States have been subject to environmental assessment under the National Environmental Policy Act (NEPA) since 1971. NEPA documentation prepared for programmatic policy decision-making within the nuclear fuel cycle and concurrent federal policy are examined as they relate to radioactive waste management in this paper. Key programmatic environmental impact statements that address radioactive waste management include: the Atomic Energy Commission document on management of commercial high-level and transuranium-contaminated radioactive waste, which focussed on development of engineered retrievable surface storage facilities (RSSF); the Nuclear Regulatory Commission (NRC) document on use of recycled plutonium in mixed oxide fuel in light water cooled reactors, which focussed on plutonium recycle and RSSF; the NRC statement on handling of spent light water power reactor fuel, which focussed on spent fuel storage; and the Department of Energy (DOE) statement on management of commercially generated radioactive wastes, which focussed on development of deep geologic repositories. DOE is currently pursuing the deep geologic repository option, with monitored retrievable storage as a secondary option.

  9. 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.

  10. 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.

  11. 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.”

  12. Radioactive waste repository site selection in the Republic of Slovenia

    SciTech Connect

    Jeran, M.; Duhovnik, B.

    1993-12-31

    The report shows the procedure for the low and intermediate level radwaste (LLW and ILW) repository site selection and the work performed up to the present. The procedure for the repository site selection is divided into four steps. In the first step the unsuitable areas are excluded by taking into consideration the rough exclusion criteria. In the second step, the remaining suitable areas are screened to identify the potential sites with respect to preference criteria. In the third step three to five candidate sites were assessed and selected among the potential sites. In the final, the fourth step, detailed site investigation and confirmation of one or two most suitable sites will follow. In Slovenia the 1st, the 2nd and the 3rd step of site selection have been completed, while step 4 is now in progress.

  13. 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.

  14. 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

  15. 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.

  16. Microbiology in nuclear waste disposal: interfaces and reaction fronts.

    PubMed

    McKinley, I G; Hagenlocher, I; Alexander, W R; Schwyn, B

    1997-07-01

    It is now generally acknowledged that microbial populations will be present within nuclear waste repositories and that the consequences of such activity on repository performance must be assessed. Various modelling approaches--based either on mass balance/thermodynamics or on kinetics--have been developed to provide scoping estimates of the possible development of these populations. Past work has focused on particular areas of the repository which can be considered relatively homogeneous and hence can be represented by some kind of 'box' or 'mixing tank'. In reality, however, waste repositories include a range of engineering materials (steel, concrete, etc.) which are emplaced at depth in a rock formation. Strong chemical gradients--of the type which may be exploited by lithoautotrophic microbial populations--are likely to be found at the contacts between different materials and at the interface between the engineered structures and the host rock. Over the long timescales considered, solute transport processes will cause the locations of strong chemical gradients to move, forming reaction fronts. The high-pH plume resulting from the leaching of cement/concrete in some repository types is a particularly important example of such a reaction front. Redox fronts, which may occur in different areas of all kinds of repositories, also play an important role and would be locations where microbial activity is likely to be significant. In this paper, the key microbial processes expected at (or around) interfaces and fronts will be discussed, with particular emphasis on the development of quantitative models. The applicability of the models used wil be tested by considering similar fronts which can be found in natural systems.

  17. 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

  18. 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].

  19. 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.

  20. The Nuclear Waste Policy Act, as amended, with appropriations acts appended. Revision 1

    SciTech Connect

    1995-02-01

    This act provides for the development of repositories for the disposal of high-level radioactive wastes, low-level radioactive wastes, and spent nuclear fuels. In addition, it establishes research and development programs, as well as demonstration programs regarding the disposal of these wastes. This Act consists of the Act of Jan. 7, 1983 (Public Law 97-425; 96 Stat. 2201), as amended by Public Law 100-203 and Public Law 102-486.

  1. Feasibility of Lateral Emplacement in Very Deep Borehole Disposal of High Level Nuclear Waste

    DTIC Science & Technology

    2010-06-01

    Boiling Water Reactor (BWR) assemblies. 1.3 Overview of the Deep Borehole Concept 1.3.1 Nuclear Waste Any national nuclear waste repository must be...Dept. of Nuclear Science and Engineering, September 2004. 2 “Light-Water Reactor Fuel,” Nuclear Fuel Industries, 2010, Accessed 7 May 2010 at http...Report TM- 63 Jer 010 at 1965, pg. 352. d, pg. 354. 62 Charles W. Fo System for Spent- Nuclear Fuel (SNF) and its Applicability to Lightwater Reactor

  2. Plasma filtering techniques for nuclear waste remediation

    DOE PAGES

    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.

  3. 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. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Ramifications of risk measures in implementing quantitative performance assessment for the proposed radioactive waste repository at Yucca Mountain, Nevada, USA.

    PubMed

    Mohanty, Sitakanta; Codell, Richard B

    2004-06-01

    As part of its preparation to review a potential license application from the U.S. Department of Energy (DOE), the U.S. Nuclear Regulatory Commission (NRC) is examining the performance of the proposed Yucca Mountain nuclear waste repository. In this regard, we evaluated postclosure repository performance using Monte Carlo analyses with an NRC-developed system model that has 950 input parameters, of which 330 are sampled to represent system uncertainties. The quantitative compliance criterion for dose was established by NRC to protect inhabitants who might be exposed to any releases from the repository. The NRC criterion limits the peak-of-the-mean dose, which in our analysis is estimated by averaging the potential exposure at any instant in time for all Monte Carlo realizations, and then determining the maximum value of the mean curve within 10000 years, the compliance period. This procedure contrasts in important ways with a more common measure of risk based on the mean of the ensemble of peaks from each Monte Carlo realization. The NRC chose the former (peak-of-the-mean) because it more correctly represents the risk to an exposed individual. Procedures for calculating risk in the expected case of slow repository degradation differ from those for low-probability cases of disruption by external forces such as volcanism. We also explored the possibility of risk dilution (i.e., lower calculated risk) that could result from arbitrarily defining wide probability distributions for certain parameters. Finally, our sensitivity analyses to identify influential parameters used two approaches: (1). the ensemble of doses from each Monte Carlo realization at the time of the peak risk (i.e., peak-of-the-mean) and (2). the ensemble of peak doses calculated from each realization within 10000 years. The latter measure appears to have more discriminatory power than the former for many parameters (based on the greater magnitude of the sensitivity coefficient), but can yield

  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. Nuclear waste management. Semiannual progress report, October 1983-March 1984

    SciTech Connect

    McElroy, J.L.; Powell, J.A.

    1984-06-01

    Progress in the following studies on radioactive waste management is reported: defense waste technology; Nuclear Waste Materials Characterization Center; waste isolation; and supporting studies. 58 figures, 22 tables.

  7. 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.

  8. 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

  9. 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.

  10. The French Programme A development plan for a geological repository for high level and long-lived waste

    SciTech Connect

    Ouzounian, G.; Labalette, T.; Hoorelbeke, J.M.; Krieguer, J.M.

    2008-07-01

    On completion of the research required under the Waste Act of 30 December 1991, the 'Dossier 2005 Argile' submitted by ANDRA concluded that high-level and intermediate-level long-lived waste (HLW) geological disposal in the Callovo-Oxfordian clay formation is basically feasible. During 2005 this report received several assessments the conclusions of which were reported during January and February 2006: (i) the global scientific and technical report of the National Review Board (CNE), (ii) the opinion of the Nuclear Safety Authority (ASN), (iii) the report of the International Review Team conducted in the framework of an International Peer Review under the aegis of the Nuclear Energy Agency of the OECD at the request of Andra's supervisory ministries (Industry and Research). On the basis of all these elements, the results of other ways of research set up in 1991, and the reports of the public debate on management of radioactive waste, a Planning Act on sustainable waste management was publicised on 28 June 2006 (Act no. 2006-739). This Act stipulates that 'after surface storage, the ultimate radioactive waste that, for reasons of nuclear safety and radiological protection, cannot be disposed of above ground or at limited depth, shall be disposed of in a deep geological repository'. It also confers on ANDRA the task of 'conducting or contracting research and studies on storage and deep geological disposal and coordinating this research'. With regard to the reversible deep geological disposal, the Act states that 'appropriate studies and research shall be conducted for siting and designing a waste disposal facility so that on obtaining the study results, the licence application provided for can be examined in 2015, and if this licence is granted, the facility can be commissioned in 2025. The purpose of the development plan which main tasks are introduced in this paper is to present Andra's research and study strategy for meeting the objectives of the Planning Act

  11. 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.

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

    SciTech Connect

    Whitfield, M.S.

    1985-12-31

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

  13. 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.

  14. Magnetic fusion driventransmutation of nuclear waste (FTW)

    SciTech Connect

    Peng, Yueng Kay Martin; Cheng, E.T.

    1993-01-01

    The possibility of magnetic Fusion driven Transmutation of Waste (FTW) was revisted and discussed recently. Nuclear wastes include all transuranium elements: Pu isotopes, minor actinides separated from the spent fission fuel, and fissile products. Elimination of thse long-life nuclear wastes is necessary for the long-term viability of fission power. A Small Business Innovative Research program has been initiated under the leadership of TSI Research to examine the efficacy of fusion transmutation of waste utilizing small fusion drivers.

  15. 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

  16. Repository seals requirements study

    SciTech Connect

    1997-11-03

    The Yucca Mountain Site Characterization Project, managed by the Civilian Radioactive Waste Management System (CRWMS) Management and Operating Contractor (M and O) is conducting investigations to support the Viability Assessment and the License Application for a high-level nuclear waste repository at Yucca Mountain, Nevada. The sealing subsystem is part of the Yucca Mountain Waste Isolation System. The Yucca Mountain Site Characterization Project is currently evaluating the role of the sealing subsystem (shaft, ramp and exploratory borehole seals) in achieving the overall performance objectives for the Waste Isolation System. This report documents the results of those evaluations. This report presents the results of a repository sealing requirements study. Sealing is defined as the permanent closure of the shafts, ramps, and exploratory boreholes. Sealing includes those components that would reduce potential inflows above the repository, or that would divert flow near the repository horizon to allow vertical infiltration to below the repository. Sealing of such features as emplacement drifts was not done in this study because the current capability to calculate fracture flow into the drifts is not sufficiently mature. The objective of the study is to provide water or air flow performance based requirements for shafts, ramps, and exploratory boreholes located near the repository. Recommendations, as appropriate, are provided for developing plans, seals component testing, and other studies relating to sealing.

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. Gas generation and gas migration in deep geological repositories for radioactive waste

    SciTech Connect

    Haijtink, B.

    1996-12-31

    It is generally accepted that there will be some degree of gas generation in deep geological repositories for radioactive waste. This gas generation will depend on a number of factors such as the nature of the waste, the waste container, the buffer material and the near field host rock. In an ideal situation the gas generated would all dissolve in the groundwater and/or be transported away from the deep repository by the mechanisms of advection, diffusion and dispersion. However the sought-after characteristic of a repository host medium of very low permeability, e.g. bentonite buffer material and argillaceous geological media can be problematic when considering gas migration. High gas pressures might be build-up which could lead to potential fracturing of engineered barriers in the near field and enhancing groundwater flow and radionuclide migration. Various theoretical as well as experimental research activities have been undertaken to investigate the different phenomena. Within the framework of R&D programmes on Management and Storage of Radioactive Waste, conducted by the European Commission, some of the research activities are grouped together in a coordinated project named PEGASUS (Project on the Effects of GAS in an Underground Storage facility). In this project a total of about twenty research institutes and laboratories from seven different European countries are involved. This PEGASUS project will be followed up by a new project named PROGRESS (PROject of Research into Gas generation and migration in radioactive waste REpository SystemS). In this paper, an overview is given of the various research activities carried out and results obtained so far.

  2. A comparative study of discrete fracture network and equivalent continuum models for simulating flow and transport in the far field of a hypothetical nuclear waste repository in crystalline host rock

    DOE PAGES

    Hadgu, Teklu; Karra, Satish; Kalinina, Elena; ...

    2017-07-28

    One of the major challenges of simulating flow and transport in the far field of a geologic repository in crystalline host rock is related to reproducing the properties of the fracture network over the large volume of rock with sparse fracture characterization data. Various approaches have been developed to simulate flow and transport through the fractured rock. The approaches can be broadly divided into Discrete Fracture Network (DFN) and Equivalent Continuum Model (ECM). The DFN explicitly represents individual fractures, while the ECM uses fracture properties to determine equivalent continuum parameters. In this paper, we compare DFN and ECM in termsmore » of upscaled observed transport properties through generic fracture networks. The major effort was directed on making the DFN and ECM approaches similar in their conceptual representations. This allows for separating differences related to the interpretation of the test conditions and parameters from the differences between the DFN and ECM approaches. The two models are compared using a benchmark test problem that is constructed to represent the far field (1 × 1 × 1 km3) of a hypothetical repository in fractured crystalline rock. The test problem setting uses generic fracture properties that can be expected in crystalline rocks. The models are compared in terms of the: 1) effective permeability of the domain, and 2) nonreactive solute breakthrough curves through the domain. The principal differences between the models are mesh size, network connectivity, matrix diffusion and anisotropy. We demonstrate how these differences affect the flow and transport. Finally, we identify the factors that should be taken in consideration when selecting an approach most suitable for the site-specific conditions.« less

  3. A comparative study of discrete fracture network and equivalent continuum models for simulating flow and transport in the far field of a hypothetical nuclear waste repository in crystalline host rock

    NASA Astrophysics Data System (ADS)

    Hadgu, Teklu; Karra, Satish; Kalinina, Elena; Makedonska, Nataliia; Hyman, Jeffrey D.; Klise, Katherine; Viswanathan, Hari S.; Wang, Yifeng

    2017-10-01

    One of the major challenges of simulating flow and transport in the far field of a geologic repository in crystalline host rock is related to reproducing the properties of the fracture network over the large volume of rock with sparse fracture characterization data. Various approaches have been developed to simulate flow and transport through the fractured rock. The approaches can be broadly divided into Discrete Fracture Network (DFN) and Equivalent Continuum Model (ECM). The DFN explicitly represents individual fractures, while the ECM uses fracture properties to determine equivalent continuum parameters. We compare DFN and ECM in terms of upscaled observed transport properties through generic fracture networks. The major effort was directed on making the DFN and ECM approaches similar in their conceptual representations. This allows for separating differences related to the interpretation of the test conditions and parameters from the differences between the DFN and ECM approaches. The two models are compared using a benchmark test problem that is constructed to represent the far field (1 × 1 × 1 km3) of a hypothetical repository in fractured crystalline rock. The test problem setting uses generic fracture properties that can be expected in crystalline rocks. The models are compared in terms of the: 1) effective permeability of the domain, and 2) nonreactive solute breakthrough curves through the domain. The principal differences between the models are mesh size, network connectivity, matrix diffusion and anisotropy. We demonstrate how these differences affect the flow and transport. We identify the factors that should be taken in consideration when selecting an approach most suitable for the site-specific conditions.

  4. 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.

  5. Control of Nepheline Crystallization in Nuclear Waste Glass

    SciTech Connect

    Fox, Kevin

    2008-07-01

    Glass frits with a high B{sub 2}O{sub 3} concentration have been designed which, when combined with high-alumina concentration nuclear waste streams, will form glasses with durabilities that are acceptable for repository disposal and predictable using a free energy of hydration model. Two glasses with nepheline discriminator values closest to 0.62 showed significant differences in normalized boron release between the quenched and heat treated versions of each glass. X-ray diffraction confirmed that nepheline crystallized in the glass with the lowest nepheline discriminator value, and nepheline may also exist in the second glass as small nanocrystals. The high-B{sub 2}O{sub 3} frit was successful in producing simulated waste glasses with no detectable nepheline crystallization at waste loadings of up to 45 wt%. The melt rate of this frit was also considerably better than other frits with increased concentrations of Na{sub 2}O.

  6. 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

  7. Initial studies to assess microbial impacts on nuclear waste disposal

    SciTech Connect

    Horn, J.M.; Meike, A.; McCright, R.D.; Economides, B.

    1996-02-20

    The impacts of the native and introduced bacteria on the performance of geologic nuclear waste disposal facilities should be evaluated because these bacteria could promote corrosion of repository components and alteration of chemical and hydrological properties of the surrounding engineered and rock barriers. As a first step towards investigating these potentialities, native and introduced bacteria obtained from post-construction Yucca Mountain (YM) rock were isolated under varying conditions, including elevated temperature, low nutrient availability, and the absence of available oxygen. Individual isolates are being screened for activities associated with microbially induced corrosion of metals (MIC). Preliminary determination of growth rates of whole YM microbial communities under varying conditions was also undertaken.

  8. 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.

  9. 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

  10. 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.

  11. Comparison of risks due to HLW and SURF repositories in bedded salt

    SciTech Connect

    Chu, M.S.Y.; Ortiz, N.R.; Wahi, K.K.

    1983-01-01

    A methodology was developed for use in the analysis of risks from geologic disposal of nuclear wastes. This methodology is applied to two conceptual nuclear waste repositories in bedded salt containing High-Level Waste (HLW) and Spent Un-Reprocessed Fuel (SURF), respectively. A comparison of the risk estimated from the HLW and SURF repositories is presented.

  12. Uncertainty and sensitivity analysis in the 2008 performance assessment for the proposed repository for high-level radioactive waste at Yucca Mountain, Nevada.

    SciTech Connect

    Helton, Jon Craig; Sallaberry, Cedric M.; Hansen, Clifford W.

    2010-05-01

    Extensive work has been carried out by the U.S. Department of Energy (DOE) in the development of a proposed geologic repository at Yucca Mountain (YM), Nevada, for the disposal of high-level radioactive waste. As part of this development, an extensive performance assessment (PA) for the YM repository was completed in 2008 [1] and supported a license application by the DOE to the U.S. Nuclear Regulatory Commission (NRC) for the construction of the YM repository [2]. This presentation provides an overview of the conceptual and computational structure of the indicated PA (hereafter referred to as the 2008 YM PA) and the roles that uncertainty analysis and sensitivity analysis play in this structure.

  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. Environmental impact of radionuclide migration in groundwater from a low-intermediate level radioactive waste repository.

    PubMed

    Wang, J S; Yang, Z F; Li, S S; Wang, Z M

    2001-04-01

    The radionuclide migration from a certain Chinese repository with low-intermediate level radioactive solid waste is studied. The migration in groundwater is analyzed and computed in detail. Under presumption of normal releasing, or the bottom of the repository has been marinated for one month with precipitation reaching 600 mm once and a 6 m aerated zone exists, a prediction for 7 radionuclides is conducted. It shows that the aerated zone is the primary barrier for migration. The migration for radionuclides 60Co, 137Cs, 90Sr, 63Ni, etc. will be retarded in it within 500 years. The concentration of 239Pu will be decreased by amount of 6 order. Only 3H and 14C can migrate through the aerated zone. The radionuclides that go through the aerated zone and enter the aquifer will exist in spring, stream and sea. Based on this, the intake dose by residents in different age group resulting from drinking contaminated spring water, eating seafood is calculated. The results showed that the impact of the repository to the key resident group is lower than the limit in national repository regulation standard. This complies with the repository management target.

  15. Draft environmental assessment: Lavender Canyon site, Utah. Nuclear Waste Policy Act (Section 112). [Contains glossary

    SciTech Connect

    Not Available

    1984-12-01

    In February 1983, the US Department of Energy (DOE) identified the Lavender Canyon site in Utah, as one of nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the Lavender Canyon site and the eight other potentially acceptable sites h

  16. 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.

  17. 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

  18. Review: Waste-Pretreatment Technologies for Remediation of Legacy Defense Nuclear Wastes

    SciTech Connect

    Wilmarth, William R.; Lumetta, Gregg J.; Johnson, Michael E.; Poirier, Micheal R.; Thompson, Major C.; Suggs, Patricia C.; Machara, N.

    2011-01-13

    The U.S. Department of Energy (DOE) is responsible for retrieving, immobilizing, and disposing of radioactive waste that has been generated during the production of nuclear weapons in the United States. The vast bulk of this waste material is stored in underground tanks at the Savannah River Site in South Carolina and the Hanford Site in Washington State. The general strategy for treating the radioactive tank waste consists of first separating the waste into high-level and low-activity fractions. This initial partitioning of the waste is referred to as pretreatment. Following pretreatment, the high-level fraction will be immobilized in a glass form suitable for disposal in a geologic repository. The low-activity waste will be immobilized in a waste form suitable for disposal at the respective site. This paper provides a review of recent developments in the application of pretreatment technologies to the processing of the Hanford and Savannah River radioactive tank wastes. Included in the review are discussions of 1) solid/liquid separations methods, 2) cesium separation technologies, and 3) other separations critical to the success of the DOE tank waste remediation effort. Also included is a brief discussion of the different requirements and circumstances at the two DOE sites that have in some cases led to different choices in pretreatment technologies.

  19. 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.

  20. 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.

  1. 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.

  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. 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.

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Safety assessment for a potential SNF repository and its implication to the proliferation resistance nuclear fuel cycle

    SciTech Connect

    Hwang, Y.; Jeong, M.S.; Seo, C.S.

    2007-07-01

    decay of I-129. Also, Sr-90 and Cs-137 shares 89 % of the total decay heat. In this sense, the pyro-processing contributes significantly to reduce the risks and doses of disposal. Also, the separation of decay heat generating nuclides significantly reduces the disposal areas. Results indicate the followings: (1) To minimize the annual dose, it is important to properly manage the release mechanism of I-129 by pyro-processing. (2) To minimize the underground repository area, it is important to remove the decay heat sources, Cs-137 and Sr-90. (3) To minimize the burden to monitor a repository, it i s important to control long lived radionuclides such as I-129 and TRU's. If instantaneous release is gone, the source term controlled by congruent release will diminish quite significantly. Also, if heat sources are safety stored after removal above the ground for a certain period of time, then the underground repository area will be shrunken quite significantly also. These two factors are clear advantages of the pyro-processing to preserve environment and a future generation without significant worry over nuclear proliferation. The electro refining processes in combination with winning technologies will give additional benefits to the environment by removing and recycling long lived TRU's. To fully analyze the benefits of these two processes for environmental protection more detailed researches are needed: (1) To identify the accurate inventories from these processes. (2) To understand the dissolution mechanism of solidified wastes. Also, the new management concept development is recommended to effectively dispose of solidified wastes and possibly metal ingots and store heat generating waste above the ground. (authors)

  12. Unsaturated flow and transport through fractured rock related to high-level waste repositories; Final report, Phase 3

    SciTech Connect

    Evans, D.D.; Rasmussen, T.C.

    1991-01-01

    Research results are summarized for a US Nuclear Regulatory Commission contract with the University of Arizona focusing on field and laboratory methods for characterizing unsaturated fluid flow and solute transport related to high-level radioactive waste repositories. Characterization activities are presented for the Apache Leap Tuff field site. The field site is located in unsaturated, fractured tuff in central Arizona. Hydraulic, pneumatic, and thermal characteristics of the tuff are summarized, along with methodologies employed to monitor and sample hydrologic and geochemical processes at the field site. Thermohydrologic experiments are reported which provide laboratory and field data related to the effects conditions and flow and transport in unsaturated, fractured rock. 29 refs., 17 figs., 21 tabs.

  13. 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.

  14. 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.

  15. 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.

  16. Nuclear Waste Management. Semiannual progress report, April 1984-September 1984

    SciTech Connect

    McElroy, J.L.; Powell, J.A.

    1984-12-01

    Progress in the following studies on radioactive waste management is reported: defense waste technology; Nuclear Waste Materials Characterization Center; and supporting studies. 33 figures, 13 tables.

  17. Nuclear Waste Disposal: Can Government Cope?

    DTIC Science & Technology

    1983-12-01

    Codes December 1983Avlardo Dist Special The original version of this study was prepared by the author, Jackie L. Braitman, as a dissertation in partial...disposal, are to be met. The work originates from a supposition that the failure, thus far, S S of the Department of Energy (DOE) to site and develop...develop the capabilities needed to site a high-level radioactive waste repository. Lester Salamon (1981) advances a similar question in his critique of

  18. 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.

  19. Plasma Mass Filters For Nuclear Waste Reprocessing

    SciTech Connect

    Fetterman, Abraham J.; Fisch, Nathaniel J.

    2011-05-01

    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.

  20. 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.

  1. 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…

  2. 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

  3. 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.

  4. 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.

  5. 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)

  6. Repository seals requirement study

    SciTech Connect

    1997-11-03

    The Yucca Mountain Site Characterization Project, managed by the Civilian Radioactive Waste Management System (CRWMS) Management and Operating Contractor (M and O) is conducting investigations to support the Viability Assessment and the License Application for a high-level nuclear waste repository at Yucca Mountain, Nevada. The sealing subsystem is part of the Yucca Mountain Waste Isolation System. The Yucca Mountain Site Characterization Project is currently evaluating the role of the sealing subsystem (shaft, ramp and exploratory borehole seals) in achieving the overall performance objectives for the Waste Isolation System. This report documents the results of those evaluations. The objective of the study is to provide water or air flow performance based requirements for shafts, ramps, and exploratory boreholes located near the repository. Recommendations, as appropriate, are provided for developing plans, seals component testing, and other studies relating to sealing.

  7. 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.

  8. 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.

  9. 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

  10. Neural network analysis of nuclear waste glass composition vs durability

    SciTech Connect

    Seibel, C.K.

    1994-04-01

    The relationship between the chemical composition of oxide glasses and their physical properties is poorly understood, but it is becoming more important as vitrification (transformation into glass) of high-level nuclear waste becomes the favored method for long-term storage. The vitrified waste will be stored deep in geologic repositories where it must remain intact for at least 10,000 years. A strong resistance to groundwater exposure; i.c. a slow rate of glass dissolution, is of great importance. This project deals specifically with glass samples developed and tested for the nuclear fuel reprocessing facility near West Valley, New York. This facility needs to dispose of approximately 2.2 million liters of high-level radioactive liquid waste currently stored in stainless steel tanks. A self-organizing, artificial neural network was used to analyze the trends in the glass dissolution data for the effects of composition and the resulting durability of borosilicate glasses in an aqueous environment. This durability data can be used to systematically optimize the properties of the complex nuclear glasses and slow the dissolution rate of radionuclides into the environment.

  11. Yucca Mountain and High-Level Nuclear Waste Disposal: Contributions of Mineralogy to Policy

    NASA Astrophysics Data System (ADS)

    Macfarlane, A.

    2006-05-01

    High-level nuclear waste from the nuclear power industry and the nuclear weapons complex requires a geologic repository for disposal. The United States has identified a site at Yucca Mountain, Nevada for this purpose. Site selection and characterization have relied on input from earth scientists, including information about waste form behavior in a repository environment. The question of waste forms is central to the issue of reducing uncertainties in predicting the performance of a geologic repository over thousands to hundreds of thousands of years, the periods covered by standards that govern the release of radioactivity into the environment. The repository characterized by the U.S. Department of Energy at Yucca Mountain will be located in the unsaturated zone and will consequently provide an oxidizing environment for the waste emplaced there. The geochemical environment will have a large impact on the behavior of the waste, the majority of which will be spent nuclear fuel from nuclear power plants. Spent fuel is largely composed of UO2, in addition to a small fraction of fission products and actinides. Studies of natural analogues have shown that UO2 is not stable in an oxidizing environment in the presence of water and will alter to other phases. The ability of these alteration phases to contain radioactivity is still a subject of analysis. Other countries have addressed the issue of waste form stability by selecting a reducing environment in a location below the water table for their repositories. Such a choice increases the durability of spent fuel by orders of magnitude and thus reduces the uncertainties associated with predicting the performance of the repository. In the United States, the emphasis has turned away from the selection of appropriate natural barriers to transport of radioactivity and towards improvement of engineered barriers. This shift reflects a decision to abandon the natural barriers in favor of engineered ones, resulting in the

  12. 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.

  13. 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

  14. 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.

  15. 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)

  16. 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.

  17. 10 CFR 1.18 - Advisory Committee on Nuclear Waste.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 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, as...

  18. 10 CFR 1.18 - Advisory Committee on Nuclear Waste.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 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, as...

  19. 10 CFR 1.18 - Advisory Committee on Nuclear Waste.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 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, as...

  20. 10 CFR 1.18 - Advisory Committee on Nuclear Waste.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 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, as...

  1. ``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.

  2. 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

  3. 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.

  4. 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.

  5. 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,