Creep, a potential degradation mechanism of Zircaloy cladding after repository disposal of spent nuclear fuel, has been investigated. The deformation and fracture map methodology has been used to predict maximum allowable initial storage temperatures to achieve a thousand year life without rupture as a function of spent-fuel history. Maximum allowable temperatures are 340{degree}C (613 K) for typically stressed rods (70--100 MPa) and 300{degree}C (573 K) for highly stressed rods (140--160 MPa). 10 refs., 2 figs.

Consumer and producer services, the latter in particular, are expected to become an important means of diversification and employment growth to the economy of Nevada. It has been suggested that the siting of the nuclear waste repository at Yucca Mountain, Nevada, will lead to a significant reduction in the amenity value of the state and, consequently, the ability of the state to attract these nonmanufacturing industries. This report reviews the literature dealing with factors important to the location of services, with an emphasis on producer services, to determine whether amenities, which have been shown to be an important locational consideration for some manufacturing firms, similarly affect the location of services. The report finds little substantive evidence to link amenities with the location of service firms, although the process by which these firms` locations are chosen is not well understood. Research in this area is comparatively recent, and although a number of theories of service location have been developed, the majority of research is exploratory in scope.

The disposal of the Nation`s spent nuclear fuel and high-level waste has been studied for many years. The Nuclear Waste Policy Act of 1982 and the subsequent Nuclear Waste Policy Amendments Act (NWPAA) of 1987 provide the legislative framework under which the Department of Energy (DOE) must operate when evaluating potential sites for the geologic disposal of spent nuclear fuel and high-level waste. Additionally, the DOE must comply with regulations published by the Environmental Protection Agency (EPA) in 40 CFR 191, ``Environmental Radiation Protection Standards for Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes`` and the Nuclear Regulatory Commission (NRC) in 10 CFR 60. ``Disposal of High-Level Radioactive Wastes in Geologic Repositories.`` The DOE also operates under its own regulation, 10 CFR 960. ``General Guidelines for the Recommendation of Sites for Nuclear Waste Repositories.`` The DOE has devoted considerable resources to this pro gram, which is managed by the Office of Civilian Radioactive Waste Management (OCRWM). Disposal of spent nuclear fuel and high-level waste in a geologic repository has never before been done anywhere in the world. Since this is a first-of-a-kind facility, extreme care must be taken to ensure that all environmental and public health …

The Chemical Technology Division of Argonne National Laboratory is performing experiments in support of the waste package development of the Yucca Mountain Project (formerly the Nevada Nuclear Waste Storage Investigations Project). Experiments in progress include (1) the development and performance of a durability test in unsaturated conditions, (2) studies of waste form behavior in an irradiated atmosphere, (3) studies of behavior in water vapor, and (4) studies of naturally occurring glasses to be used as analogues for waste glass behavior. This report documents progress made during the period of January--June 1988. 21 refs., 37 figs., 12 tabs.

Volcanic rock samples collected from the Nevada Test Site, Nye County, Nevada, between 1960 and 1985 were analyzed by thin section to obtain petrographic mode data. In order to provide rapid accessibility to the entire database, all data from the cards were entered into a computerized database. This computer format will enable workers involved in stratigraphic studies in the Nevada Test Site area and other locations in southern Nevada to perform independent analyses of the data. The data were compiled from the mode cards into two separate computer files. The first file consists of data collected from core samples taken from drill holes in the Yucca Mountain area. The second group of samples were collected from measured sections and surface mapping traverses in the Nevada Test Site area. Each data file is composed of computer printouts of tables with mode data from thin section point counts, comments on additional data, and location data. Tremendous care was taken in transferring the data from the cards to computer, in order to preserve the original information and interpretations provided by the analyzer. In addition to the data files above, a file is included that consists of Nevada Test Site petrographic data published in …

A number of cores, taken from within and near Walker Lake, Nevada are being studied by various investigators in order to evaluate the late-Pleistocene paleoclimate of the west-central Great Basin. In particular, the cores provide records that can be interpreted in terms of past climate and compared to proposed numerical models of the region`s climate. All of these studies are being carried out as part of an evaluation of the regional paleoclimatic setting of a proposed high-level nuclear waste storage facility at Yucca Mountain, Nevada. Changes in past climate often manifest themselves in changes in sedimentary processes or in changes in the volume of sediment transported by those processes. One fundamental sediment property that can be related to depositional processes is grain size. Grain size effects other physical properties of sediment such as porosity and permeability which, in turn, affect the movement and chemistry of fluids. The purposes of this report are: (1) to document procedures of sample preparation and analysis, and (2) to summarize grain-size statistics for 659 samples from Walker Lake cores 84-4, 84-5, 84-8 and 85-2. Plots of mean particle diameter, percent sand, and the ratio of silt to clay are illustrated for various depth intervals within …

Packages of high-level waste are to be emplaced in unsaturated tuff at the proposed Yucca Mountain repository. Each cylindrical waste package is separated from surrounding rock by a 2-cm air gap. A possible mechanism for release of radionuclides is the dripping of ground water onto waste packages. Drips are assumed to penetrate cracks in failed container and to dissolve radionuclides as the partly failed container fills and overflows. For this wet-drip scenario, with assumed constant drip rate, we have developed analytical solutions for the time-dependent release rates of radionuclides to the surrounding rock. Release rates have been calculated for key radionuclides. 7 refs., 3 figs.

The Department of Energy`s Office of Civilian Radioactive Waste Management (OCRWM) Program is studying Yucca Mountain, Nevada as a suitable site for the first US high-level nuclear waste repository. Lawrence Livermore National Laboratory (LLNL) has the responsibility for designing and developing the waste package for the permanent storage of high-level nuclear waste. This report is a summary of the technical activities for the LLNL/YMP Nuclear Waste Disposal Container Fabrication and Closure Development Project. Candidate welding closure processes were identified in the Phase 1 report. This report discusses Phase 2. Phase 2 of this effort involved laboratory studies to determine the optimum fabrication and closure processes. Because of budget limitations, LLNL narrowed the materials for evaluation in Phase 2 from the original six to four: Alloy 825, CDA 715, CDA 102 (or CDA 122) and CDA 952. Phase 2 studies focused on evaluation of candidate material in conjunction with fabrication and closure processes.

The analytical expression used to model glass reaction in computer simulations such as EQ6 is compared to experiments used to support the simulations. The expression correctly predicts the acceleration observed in experiments performed at high glass surface area/leachant volume ratios (SA/V) upon the formation of secondary phases. High resolution microscopal analysis of reacted glass samples suggests that the accelerated nature of the reaction after secondary phase formation is due to changes in the reaction affinity (i.e., is a solution affect) and not a change in the glass reaction mechanism. Solutions generated on samples reacted in steam are consistent with the effects of the secondary phases predicted in the model. Experiments which lead to the generation of secondary phases within short reaction times can be used to identify important secondary phases which must be included in the data base of computer simulations to correctly project long-term glass reaction behavior. 6 refs., 1 fig., 1 tab.

A repository excavated within the unsaturated zone may release carbon (C)-14 dioxide in amounts that exceed limits imposed by the Environmental Protection Agency (EPA) and the Nuclear Regulatory Commission (NRC). The release would not threaten the general population, but may expose some hypothetical maximally exposed individual to 0.0005 millirems/year. Yet a repository`s releases of C-14 dioxide are strictly regulated, perhaps unintentionally. The EPA and NRC regulations could force the Department of Energy to design and fabricate an expensive 10,000-year waste package solely for the sake of controlling releases of C-14 dioxide. This paper argues that the repository regulations should exempt releases of C-14 dioxide or at least impose more equitable limits. 21 refs., 1 tab.

A brief description of the Exploratory Shaft based site characterization testing program for the Yucca Mountain Project of the permanent disposal of high level radioactive waste is briefly described in this paper. Details of the testing program are presented in the DOE-issued Site Characterization Plan. Overview of the current planning process and status of various activities is briefly described. This study will reevaluate the mining method, ESF location and any changes in the ESF testing program. 2 refs., 2 figs., 1 tab.

Benchmarking calculations using the code LLUVIA have been performed in support of the code verification activity (COVE 2A) for the Yucca Mountain Project (YMP). LLUVIA is a program designed for the efficient solution of one-dimensional, steady flow through multiple layers of saturated or partially saturated, fractured, porous media. The benchmarking calculations involve six steady-state and six time-dependent infiltration problems. For the time-dependent analyses, LLUVIA reported only the final steady-state results. This report documents preliminary calculations, resulting code modifications and final calculations for the COVE 2A study. 7 refs., 79 figs., 3 tabs.

The chemical interactions of dissolved radionuclides with mineral surfaces along flowpaths from the proposed repository to the accessible environment around Yucca Mountain constitute one of the potential barriers to radionuclide migration at the site. Our limited understanding of these interactions suggests their details will be complex and will involve control by numerous chemical and physical parameters. It appears unlikely that we will understand all the details of these reactions or obtain all the site data required to evaluate each of them in the time available for site characterization. Yet, performance assessment calculations will require some form of coupling of chemical interaction models will hydrologic flow models for the site. Clearly, strategies will be needed to bound the problem without compromising the reliability of the performance assessment calculations required for site suitability analysis. The main purpose of this paper is to describe such a strategy. 39 refs., 7 figs., 5 tabs.

The OCRWM Bulletin is published by the Department of Energy, Office of Civilian Radioactive Waste Management to provide current information about the national program for managing spent fuel and high-level radioactive waste. This document is a compilation of issues from the 1989 calendar year. A table of contents and one index have been provided to assist in finding information contained in this year`s Bulletins. The pages have been numbered consecutively at the bottom for easy reference. 7 figs.

The Nuclear Energy Agency of the organization for Economic Cooperation and Development (OECD/NEA) sponsors the International Stripa Project. The objectives of the Stripa Project are to develop techniques for characterizing sites located deep in rock formations that are potentially suitable for the geologic disposal of high-level radioactive wastes and to evaluate particular engineering design considerations that could enhance the long-term safety of a high-level radioactive waste repository in a geologic medium. The purpose of this paper is to briefly summarize the research conducted at Stripa and discuss the ways in which the technology developed for the Stripa Project has been and will be transfered to the United States Civilian Radioactive Waste Management Program`s Yucca Mountain Project. 3 refs., 2 figs.

This report discusses the scope of risk assessment strategies in the management of the transport of high-level radioactive wastes. In spite of the shortcomings of probabilistic risk assessment(PRA), the Transportation Needs Assessment recommended this as the preferred methodology to assess the risks of high level nuclear waste (HLNW) transportation. A PRA also will need to heed the lessons learned from the development and application of PRA elsewhere, such as in the nuclear power industry. A set of guidelines will aid this endeavor by outlining the appropriate scope, content, and use of a risk assessment which is more responsive to the uncertainties, human-technical interactions, social forces, and iterative relationship with risk management strategies, than traditional PRAS. This more expansive definition, which encompasses but is not totally reliant on rigorous data requirements and quantitative probability estimates, we term Comprehensive Risk Assessment (CRA) Guidelines will be developed in three areas: the limitations of existing methodologies and suggested modifications; CRA as part of a flexible, effective, adaptive risk management system for HLNW transportation; and, the use of CRA in risk communication.

Solubility and speciation data are important in understanding aqueous radionuclide transport through the geosphere. They define the source term for transport retardation processes such as sorption and colloid formation. Solubility and speciation data are useful in verifying the validity of geochemical codes that are part of the predictive transport models. Radionuclide solubility studies in groundwaters from a repository region will provide limits on radionuclide concentrations in these waters. Meaningful thermodynamically defined solubility studies must satisfy four criteria: (1) solution equilibrium conditions, (2) effective and complete phase separation, (3) a well-defined solid phase, and (4) knowledge of the speciation/oxidation state of the soluble species at equilibrium. Results from solubility and speciation experiments of {sup 237}NpO{sub 2}{sup +}, {sup 239}Pu{sup 4+}, and {sup 241}Am{sup 3+}/Nd{sup 3+} in J-13 groundwater (from the Yucca Mountain region, Nevada, which is being investigated as a potential high-level nuclear waste disposal site) at three different temperatures (25{degrees}, 60{degrees}, and 90{degrees}C) and pH values (6, 7, and 8.5) are presented.

The Modal Study (NUREG/CR-4829) attempts to upgrade the analysis of spent nuclear fuel transportation accidents, and to verify the validity of the present regulatory scheme of cask performance standards as a means to minimize risk. While an improvement over many prior efforts in this area (such as NUREG-0170), it unfortunately fails to create a realistic simulation either of a shipping cask, the severe conditions to which it could be subjected, or the potential damage to the spent fuel cargo during an accident. There are too many deficiencies in its analysis to allow acceptance of its results for the presumed cask design, and many pending changes in new containers, cargoes and shipping patterns will limit applicability of the Modal Study to future shipments. In essence, the Modal Study is a good start, but is too simplistic, incomplete, outdated and open to serious question to be used as the basis for any present-day environmental or risk assessment of spent fuel transportation. It needs to be redone, with peer review during its production and experimental verification of its assumptions, before it has any relevance to the shipments planned to Yucca Mountain. Finally, it must be expanded into a full risk assessment by inputing …

This third biennial Report of the Nevada Commission on Nuclear Projects has been prepared in fulfillment of the requirements of NRS 459.0092, which stipulates that the Commission shall report to the Governor and Legislature on any matter relating to radioactive waste disposal the Commission deems appropriate and advise and make recommendations on the policy of the State concerning nuclear waste disposal projects. Chapter One of the Report presents a brief overview of the Commission`s functions and statutory charges. It also contains a summary of developments which have affected the overall nuclear waste disposl issue since the last Commission Report was published in November, 1988. Chapter Two contains a synthesis of Commission activities and reports on the findings of the Commission relative to the geotechnical, environmental, socioeconomic, transportation, intergovernmental and legal aspects of federal and State nuclear waste program efforts.

In this report we summarize the analyses of the time-dependent mass transfer of radionuclides from a waste solid into surrounding porous or fractured media that have been developed at the University of California, Berkeley. For each analysis we describe the conceptual model, we present the governing equations and the resulting analytic solutions, and we illustrate the results. Designers of geologic disposal systems for solid waste must predict the long-term time-dependent rate of dissolution of toxic contaminants in ground water, to provide the source term for predicting the later transport of these contaminants to the environment. Mass-transfer analysis is being used to predict rates of dissolution and release of radioactive constituents in future repositories for high-level radioactive waste, and it has been applied to predict the life of a copper container for high-level radioactive waste. Mechanistic analysis of mass-transfer is based on well-established theory of diffusive-convective transport. Its application requires experimental measurement of well-defined parameters such as porosity, solubility, diffusion coefficient, and pore velocity. Our first analysis assumed a waste solid in direct contact with porous rock. Subsequently we analyzed the more realistic situations of backfill between the waste and rock, rock with discrete fractures as well as pores, and the …

Specimens of three copper-base materials were corrosion tested with gamma radiation exposure dose rates in the range of 1.9 {times} 10{sup 3} R/h to 4.9 {times} 10{sup 5} R/h. Materials used were pure copper, 7% aluminum bronze and 30% copper-nickel. Exposures were performed in moist air at 95{degree}C and 150{degree}C and liquid Well J-13 water at 95{degree}C, for periods of up to 16 months. Specimens were monitored for uniform weight loss, stress-induced corrosion and crevice corrosion. Specimen surfaces were examined visually at 10X magnification as well as by Auger Electron Spectroscopy, x-ray diffraction and metallography. Corrosion was not severe in any of the cases. In general, the pure copper was corroded most uniformly while the copper-nickel was the least reproducibly corroded. 11 refs, 40 figs., 15 tabs.

Computer graphics systems that provide interactive display and manipulation of three-dimensional data are powerful tools for the analysis and communication of technical information required for characterization and design of a geologic repository for nuclear waste. Greater understanding of site performance and repository design information is possible when performance-assessment modeling results can be visually analyzed in relation to site geologic and hydrologic information and engineering data for surface and subsurface facilities. In turn, this enhanced visualization capability provides better communication between technical staff and program management with respect to analysis of available information and prioritization of program planning. A commercially-available computer system was used to demonstrate some of the current technology for three-dimensional visualization within the architecture of systems for nuclear waste management. This computer system was used to interactively visualize and analyze the information for two examples: (1) site-characterization and engineering data for a potential geologic repository at Yucca Mountain, Nevada; and (2) three-dimensional simulations of a hypothetical release and transport of contaminants from a source of radionuclides to the vadose zone. Users may assess the three-dimensional distribution of data and modeling results by interactive zooming, rotating, slicing, and peeling operations. For those parts of the database where information is …

The total-system life-cycle cost (TSLCC) analysis for the Department of Energy`s (DOE) Civilian Radioactive Waste Management Program is an ongoing activity that helps determine whether the revenue-producing mechanism established by the Nuclear Waste Policy Act of 1982 - a fee levied on electricity generated and sold by commercial nuclear power plants - is sufficient to cover the cost of the program. This report provides cost estimates for the sixth annual evaluation of the adequacy of the fee. The costs contained in this report represent a preliminary analysis of the cost impacts associated with the Secretary of Energy`s Report to Congress on Reassessment of the Civilian Radioactive Waste Management Program issued in November 1989. The major elements of the restructured program announced in this report which pertain to the program`s life-cycle costs are: a prioritization of the scientific investigations program at the Yucca Mountain candidate site to focus on identification of potentially adverse conditions, a delay in the start of repository operations until 2010, the start of limited waste acceptance at the monitored retrievable storage (MRS) facility in 1998, and the start of waste acceptance at the full-capability MRS facility in 2,000. Based on the restructured program, the total-system cost for …

The Hydrologic Code Intercomparison Project (HYDROCOIN) was formed to evaluate hydrogeologic models and computer codes and their use in performance assessment for high-level radioactive-waste repositories. This report describes the results of a study for HYDROCOIN of model sensitivity for isothermal, unsaturated flow through layered, fractured tuffs. We investigated both the types of flow behavior that dominate the performance measures and the conditions and model parameters that control flow behavior. We also examined the effect of different conceptual models and modeling approaches on our understanding of system behavior. The analyses included single- and multiple-parameter variations about base cases in one-dimensional steady and transient flow and in two-dimensional steady flow. The flow behavior is complex even for the highly simplified and constrained system modeled here. The response of the performance measures is both nonlinear and nonmonotonic. System behavior is dominated by abrupt transitions from matrix to fracture flow and by lateral diversion of flow. The observed behaviors are strongly influenced by the imposed boundary conditions and model constraints. Applied flux plays a critical role in determining the flow type but interacts strongly with the composite-conductivity curves of individual hydrologic units and with the stratigraphy. One-dimensional modeling yields conservative estimates of distributions of …