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Sample records for operations yucca mountain

  1. YUCCA MOUNTAIN SITE DESCRIPTION

    SciTech Connect

    A.M. Simmons

    2004-04-16

    The ''Yucca Mountain Site Description'' summarizes, in a single document, the current state of knowledge and understanding of the natural system at Yucca Mountain. It describes the geology; geochemistry; past, present, and projected future climate; regional hydrologic system; and flow and transport within the unsaturated and saturated zones at the site. In addition, it discusses factors affecting radionuclide transport, the effect of thermal loading on the natural system, and tectonic hazards. The ''Yucca Mountain Site Description'' is broad in nature. It summarizes investigations carried out as part of the Yucca Mountain Project since 1988, but it also includes work done at the site in earlier years, as well as studies performed by others. The document has been prepared under the Office of Civilian Radioactive Waste Management quality assurance program for the Yucca Mountain Project. Yucca Mountain is located in Nye County in southern Nevada. The site lies in the north-central part of the Basin and Range physiographic province, within the northernmost subprovince commonly referred to as the Great Basin. The basin and range physiography reflects the extensional tectonic regime that has affected the region during the middle and late Cenozoic Era. Yucca Mountain was initially selected for characterization, in part, because of its thick unsaturated zone, its arid to semiarid climate, and the existence of a rock type that would support excavation of stable openings. In 1987, the United States Congress directed that Yucca Mountain be the only site characterized to evaluate its suitability for development of a geologic repository for high-level radioactive waste and spent nuclear fuel.

  2. Yearly report, Yucca Mountain project

    SciTech Connect

    Brune, J.N.

    1992-09-30

    We proposed to (1) Develop our data logging and analysis equipment and techniques for analyzing seismic data from the Southern Great Basin Seismic Network (SGBSN), (2) Investigate the SGBSN data for evidence of seismicity patterns, depth distribution patterns, and correlations with geologic features (3) Repair and maintain our three broad band downhole digital seismograph stations at Nelson, nevada, Troy Canyon, Nevada, and Deep Springs, California (4) Install, operate, and log data from a super sensitive microearthquake array at Yucca Mountain (5) Analyze data from micro-earthquakes relative to seismic hazard at Yucca Mountain.

  3. Yucca Mountain tuffs

    SciTech Connect

    1996-08-01

    This is a compilation of petrographic slides detailing the microstructure and petrographic character of the tuff deposits associated with the Yucca Mountain radioactive waste repository. It describes crystal structures, clay alterations, and mineral associations. The paper contains a description of the petrographic thin-sections but contains no narrative or conclusions of what the slides suggest with regards to the facility.

  4. DOE's Yucca Mountain Studies.

    ERIC Educational Resources Information Center

    Department of Energy, Washington, DC.

    This booklet is about the disposal of high-level nuclear waste in the United States with a particular focus on Yucca Mountain, Nevada as a repository site. Intended for readers who do not have a technical background, the booklet discusses why scientists and engineers think high-level nuclear waste may be disposed of safely underground. An…

  5. YUCCA MOUNTAIN PROJECT - A BRIEFING --

    SciTech Connect

    NA

    2003-08-05

    This report has the following articles: Nuclear waste--a long-term national problem; Spent nuclear fuel; High-level radioactive waste; Radioactivity and the environment; Current storage methods; Disposal options; U.S. policy on nuclear waste; The focus on Yucca Mountain; The purpose and scope of the Yucca Mountain Project; The approach for permanently disposing of waste; The scientific studies at Yucca Mountain; The proposed design for a repository at Yucca Mountain; Natural and engineered barriers would work together to isolate waste; Meticulous science and technology to protect people and the environment; Licensing a repository; Transporting waste to a permanent repository; The Environmental Impact Statement for a repository; Current status of the Yucca Mountain Project; and Further information available on the Internet.

  6. Yucca Mountain Milestone

    SciTech Connect

    Hunt, Rod

    1997-06-09

    The Department of Energy project to determine if the Yucca Mountain site in Nevada is suitable for geologic disposal of high-level nuclear waste reached a major milestone in late April when a 25-foot-diameter tunnel boring machine ``holed through'' completing a five-mile-long, horseshoe-shaped excavation through the mountain. When the cutting-head of the giant machine broke through to daylight at the tunnel's south portal, it ended a 2 1/2-year excavation through the mountain that was completed ahead of schedule and with an outstanding safety record. Video of the event was transmitted live by satellite to Washington, DC, where it was watched by Secretary of Energy Frederico Pena and other high-level DOE officials, signifying the importance of the project's mission to find a repository for high-level nuclear waste and spent nuclear fuel produced by nuclear power plants. This critical undertaking is being performed by DOE's Office of Civilian Radioactive Waste Management (OCRWM). The tunnel is the major feature of the Exploratory Studies Facility (ESF), which serves as an underground laboratory for engineers and scientists to help determine if Yucca Mountain is suitable to serve as a repository for the safe disposal of high-level nuclear waste. Morrison Knudsen's Environmental/Government Group is providing design and construction-management services on the project. The MK team is performing final design for the ESF and viability assessment design for the underground waste repository that will be built only if the site is found suitable for such a mission. In fact, if at anytime during the ESF phase, the site is found unsuitable, the studies will be stopped and the site restored to its natural state.

  7. Geology at Yucca Mountain

    SciTech Connect

    1993-05-01

    Both 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. Critics believe that there is sufficient geological evidence to rule the site unsuitable for further investigation. Some advocates claim that there is insufficient data and that investigations are incomplete, while others claim that the site is free of major obstacles. We have expanded our efforts to include both the critical evaluations of existing geological and geochemical data and the collection of field data and samples for the purpose of preparing scientific papers for submittal to journals. Summaries of the critical reviews are presented in this paper.

  8. Yucca Mountain Task 4, Final report FY 1993

    SciTech Connect

    Brune, J.N.

    1993-09-30

    Four major projects at UNRSL have been supported by NWPO-Neotectonics Yucca Mountain Task 4 funds during the last year: (1) Operation and analysis of data from the UNRSL microearthquake network at Yucca Mountain. (2) Continued operation, maintenance, and calibration of three broadband stations. Limited data analysis was also initiated. (3) Continued review by Dr. Brune of documents and literature related to seismic hazard and tectonics of the Yucca Mountain region. (4) Testing of noise levels in boreholes.

  9. Technical bases for Yucca Mountain standards

    SciTech Connect

    1995-12-31

    The United States currently has no place to dispose of the high-level radioactive waste resulting from the production of the nuclear weapons and the operation of nuclear electronic power plants. The only option under formal consideration at this time is to place the waste in an underground geologic respository at Yucca Mountain in Nevada. This book shows the extent to which the authors` scientific knowledge can guide the federal government in developing a standard to protect the health of the public from wastes in such a respository at Yucca Mountain.

  10. Microbial activity at Yucca Mountain

    SciTech Connect

    Horn, J.M.; Meike, A.

    1995-09-25

    The U.S. Department of Energy is engaged in a suitability study for a potential geological repository at Yucca Mountain, Nevada, for the containment and storage of commercially generated spent fuel and defense high-level nuclear waste. There is growing recognition of the role that biotic factors could play in this repository, either directly through microbially induced corrosion (MIC), or indirectly by altering the chemical environment or contributing to the transport of radionuclides. As a first step toward describing and predicting these processes, a workshop was held on April 10-12, 1995, in Lafayette, California. The immediate aims of the workshop were: (1) To identify microbially related processes relevant to the design of a radioactive waste repository under conditions similar to those at Yucca Mountain. (2) To determine parameters that are critical to the evaluation of a disturbed subterranean environment. (3) To define the most effective means of investigating the factors thus identified.

  11. ADVANCES IN YUCCA MOUNTAIN DESIGN

    SciTech Connect

    Harrington, P.G.; Gardiner, J.T.; Russell, P.R.Z.; Lachman, K.D.; McDaniel, P.W.; Boutin, R.J.; Brown, N.R.; Trautner, L.J.

    2003-02-27

    Since site designation of the Yucca Mountain Project by the President, the U.S. Department of Energy (DOE) has begun the transition from the site characterization phase of the project to preparation of the license application. As part of this transition, an increased focus has been applied to the repository design. Several evolution studies were performed to evaluate the repository design and to determine if improvements in the design were possible considering advances in the technology for handling and packaging nuclear materials. The studies' main focus was to reduce and/or eliminate uncertainties in both the pre-closure and post-closure performance of the repository and to optimize operations. The scope and recommendations from these studies are the subjects of this paper and include the following topics: (1) a more phased approach for the surface facility that utilize handling and packaging of the commercial spent nuclear fuel in a dry environment rather than in pools as was presented in the site recommendation; (2) slight adjustment of the repository footprint and a phased approach for construction and emplacement of the repository subsurface; and (3) simplification of the construction, fabrication and installation of the waste package and drip shield.

  12. The hydrology of Yucca Mountain

    SciTech Connect

    Flint, A.L.; Flint, L.E.; Bodvarsson, G.S.; Kwicklis, E.M.; Fabryka-Martin, J.M.

    2000-12-04

    Yucca Mountain, located in southern Nevada in the Mojave Desert, is being considered as a geologic repository for high-level radioactive waste. Although the site is arid, previous studies indicate net infiltration rates of 5-10 mm yr(-1) under current climate conditions. Unsaturated flow of water through the mountain generally is vertical and rapid through the fractures of the welded tuffs and slow through the matrix of the nonwelded tuffs. The vitric-zeolitic boundary of the nonwelded tuffs below the potential repository, where it exists, causes perching and substantial lateral flow that eventually flows through faults near the eastern edge of the potential repository and recharges the underlying groundwater system. Fast pathways are located where water flows relatively quickly through the unsaturated zone to the water table. For the bulk of the water a large part of the travel time from land surface to the potential repository horizon (similar to 300 m below land surface) is through the interlayered, low fracture density, nonwelded tuff where flow is predominantly through the matrix. The unsaturated zone at Yucca Mountain is being modeled using a three-dimensional, dual-continuum numerical model to predict the results of measurements and observations in new boreholes and excavations. The interaction between experimentalists and modelers is providing confidence in the conceptual model and the numerical model and is providing researchers with the ability to plan further testing and to evaluate the usefulness or necessity of further data collection.

  13. Yucca Mountain and The Environment

    SciTech Connect

    NA

    2005-04-12

    The Yucca Mountain Project places a high priority on protecting the environment. To ensure compliance with all state and federal environmental laws and regulations, the Project established an Environmental Management System. Important elements of the Environmental Management System include the following: (1) monitoring air, water, and other natural resources; (2) protecting plant and animal species by minimizing land disturbance; (3) restoring vegetation and wildlife habitat in disturbed areas; (4) protecting cultural resources; (5) minimizing waste, preventing pollution, and promoting environmental awareness; and (6) managing of hazardous and non-hazardous waste. Reducing the impacts of Project activities on the environment will continue for the duration of the Project.

  14. Getting Beyond Yucca Mountain - 12305

    SciTech Connect

    Halstead, Robert J.; Williams, James M.

    2012-07-01

    The U.S. Department of Energy has terminated the Yucca Mountain repository project. The U.S. Nuclear Regulatory Commission has indefinitely suspended the Yucca Mountain licensing proceeding. The presidentially-appointed Blue Ribbon Commission (BRC) on America's Nuclear Future is preparing a report, due in January 2012, to the Secretary of Energy on recommendations for a new national nuclear waste management and disposal program. The BRC Draft Report published in July 2011 provides a compelling critique of the past three decades failed efforts in the United States to site storage and disposal facilities for spent nuclear fuel (SNF) and high-level radioactive waste (HLW). However, the BRC Draft Report fails to provide detailed guidance on how to implement an alternative, successful approach to facility site selection. The comments submitted to the BRC by the State of Nevada Agency for Nuclear Projects provide useful details on how the US national nuclear waste program can get beyond the failed Yucca Mountain repository project. A detailed siting process, consisting of legislative elements, procedural elements, and 'rules' for volunteer sites, could meet the objectives of the BRC and the Western Governors Association (WGA), while promoting and protecting the interests of potential host states. The recent termination of the proposed Yucca Mountain repository provides both an opportunity and a need to re-examine the United States' nuclear waste management program. The BRC Draft Report published in July 2011 provides a compelling critique of the past three decades failed efforts in the United States to site storage and disposal facilities for SNF and HLW. It is anticipated that the BRC Final report in January 2012 will recommend a new general course of action, but there will likely continue to be a need for detailed guidance on how to implement an alternative, successful approach to facility site selection. Getting the nation's nuclear waste program back on track

  15. Robotics Scoping Study to Evaluate Advances in Robotics Technologies that Support Enhanced Efficiencies for Yucca Mountain Repository Operations

    SciTech Connect

    T. Burgess; M. Noakes; P. Spampinato

    2005-03-17

    This paper presents an evaluation of robotics and remote handling technologies that have the potential to increase the efficiency of handling waste packages at the proposed Yucca Mountain High-Level Nuclear Waste Repository. It is expected that increased efficiency will reduce the cost of operations. The goal of this work was to identify technologies for consideration as potential projects that the U.S. Department of Energy Office of Civilian Radioactive Waste Management, Office of Science and Technology International Programs, could support in the near future, and to assess their ''payback'' value. The evaluation took into account the robotics and remote handling capabilities planned for incorporation into the current baseline design for the repository, for both surface and subsurface operations. The evaluation, completed at the end of fiscal year 2004, identified where significant advantages in operating efficiencies could accrue by implementing any given robotics technology or approach, and included a road map for a multiyear R&D program for improvements to remote handling technology that support operating enhancements.

  16. Transport of neptunium through Yucca Mountain tuffs

    SciTech Connect

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

    1993-12-31

    Neptunium has a high solubility in groundwaters from Yucca Mountain. Uranium in nuclear reactors produces {sup 237}Np which has a half-life of 2.14 {times} 10{sup 6} years. Consequently, the transport of {sup 237}Np through tuffs is of major importance in assessing the performance of a high-level nuclear waste repository at Yucca Mountain. The objective of this work is to determine the amount of Np retardation that is provided by the materials in Yucca Mountain tuffs as a function of groundwater chemistry.

  17. Yucca Mountain Site Characterization Project Plan

    SciTech Connect

    Gertz, C.P.; Bartlett, J.

    1992-01-01

    The purpose of this document is to describe the Yucca Mountain Site Characterization Project (YMP) and establish an approved YMP baseline against which overall YMP progress and management effectiveness shall be measured. For the sake of brevity, this document will be referred to as the Project Plan throughout this document. This Project Plan only addresses activities up to the submittal of the repository license application (LA) to the Nuclear Regulatory Commission (NRC). A new Project Plan will be submitted to establish the technical, cost, and schedule baselines for the final design and construction phase of development extending through the start of repository operations, assuming that the site is determined to be suitable.

  18. Evaluating the Potential Impact of Using the Transport, Aging and Disposal (TAD) Canister on Yucca Mountain Pre-Closure Operations

    SciTech Connect

    Spradley, L.; Abkowitz, M.; Clarke, J.H.

    2008-07-01

    The development and preliminary use of an integrated model to explore the impact of various operational scenarios of the pre-closure waste management system of Yucca Mountain (YM) is described. The capabilities of the model are illustrated by applying it to a simplified operational scenario using Transport, Aging, and Disposal (TAD) Canisters. The application uses existing data on spent nuclear fuel to model the effect on above ground aging at YM by varying four parameters: (1) utility loading behavior, (2) thermal limit for transportation casks, (3) thermal limit for emplacement, and (4) emplacement capacity at YM. Results show that the thermal limit for emplacement is the most important parameter with respect to above ground aging demands at YM. Transportation heat limit is also important, but less so if the capacity of YM is expanded or if older fuel is sent first. Easing the constraint of the emplacement limit, if feasible, would be a preferable method of reducing aging demands, especially under an expanded emplacement capacity. Consequently, there may be incentive for Department of Energy (DOE) to either specify a lower transportation limit or a higher emplacement limit if it wishes to reduce the potential demands on the Aging Facility at YM. (authors)

  19. Review of Yucca Mountain Disposal Criticality Studies

    SciTech Connect

    Scaglione, John M; Wagner, John C

    2011-01-01

    The U.S. Department of Energy (DOE), Office of Civilian Radioactive Waste Management, submitted a license application for construction authorization of a deep geologic repository at Yucca Mountain, Nevada, in June of 2008. The license application is currently under review by the U.S. Nuclear Regulatory Commission. However,on March 3, 2010 the DOE filed a motion requesting withdrawal of the license application. With the withdrawal request and the development of the Blue Ribbon Commission to seek alternative strategies for disposing of spent fuel, the status of the proposed repository at Yucca Mountain is uncertain. What is certain is that spent nuclear fuel (SNF) will continue to be generated and some long-lived components of the SNF will eventually need a disposition path(s). Strategies for the back end of the fuel cycle will continue to be developed and need to include the insights from the experience gained during the development of the Yucca Mountain license application. Detailed studies were performed and considerable progress was made in many key areas in terms of increased understanding of relevant phenomena and issues regarding geologic disposal of SNF. This paper reviews selected technical studies performed in support of the disposal criticality analysis licensing basis and the use of burnup credit. Topics include assembly misload analysis, isotopic and criticality validation, commercial reactor critical analyses, loading curves, alternative waste package and criticality control studies, radial burnup data and effects, and implementation of a conservative application model in the criticality probabilistic evaluation as well as other information that is applicable to operations regarding spent fuel outside the reactor. This paper summarizes the work and significant accomplishments in these areas and provides a resource for future, related activities.

  20. Yucca Mountain reveals its secrets to scientists

    SciTech Connect

    Gertz, C.P.; Teitelbaum, S.

    1994-12-31

    US nuclear power plants have generated some 20,000 metric tons of waste, according to Carl P. Gertz, former Department of Energy (DOE) project manager for Yucca Mountain Site Characterization, and Sheldon Teitelbaum, senior writer for the Las Vegas-based Science Application International Corporation. In the search for disposal methods, DOE fixed on Yucca Mountain, Nevada, a {open_quotes}sprawling heap of volcanic tuff{close_quotes} situated on a parcel of federally owned land 90 miles northwest of Las Vegas. The authors maintain that Yucca Mountain`s sparse population, dry climate, deep watertable, and 5,000-foot-thick layer of compressed volcanic rock may make it a suitable long-term storage facility. Nevertheless, Gertz and Teitelbaum say, much research must be done before the site is formally adopted as a repository and begins to receive shipments of high-level nuclear waste.

  1. Viability Assessment of a Repository at Yucca Mountain. Volume 5: Costs to Construct and Operate the Repository

    SciTech Connect

    1998-12-01

    This volume presents a management summary of the cost estimate to complete the design, and to license, construct, operate, monitor, close, and decommission a Monitored Geologic Repository at Yucca Mountain in Nevada. This volume summarizes the scope, estimating methodologies, and assumptions used in development of the Monitored Geologic Repository-VA cost estimate. It identifies the key features necessary to understand the summary costs presented herein. This cost summary derives from a larger body of documented cost analysis. Volume 5 is organized to reflect this structured approach to cost estimation and contains the following sections: Section 1, Cost Elements. This section briefly defines the components of each major repository cost element. Section 2, Project Phases. This section presents the definition, as used in the estimate, of five project phases (Licensing, Pre-emplacement Construction, Emplacement Operations, Monitoring, and Closure and Decommissioning) and the schedule dates for each phase. It also contains major milestone dates and a bar chart schedule. Section 3, Major Assumptions. This section identifies key high-level assumptions for the cost estimate basis. Additional detailed assumptions are included in the appendices. Section 4, Integrated Cost Summary. This section presents a high-level roll-up of the VA costs resulting from the estimating work. The tables and figures contained in this section were compiled from the more detailed cost estimates in the appendices. Section 5, References. This section identifies the references that support this cost volume. Appendices. For each major repository cost element, Appendices B-F [B, C, D, E, F] presents additional information on the scope of cost elements, identifies methodologies used to develop the cost estimates, lists underlying cost assumptions, and tabulates summary results. Appendix A contains a glossary to assist the reader in understanding the terminology in Volume 5. Appendix G presents costs

  2. Transportation cask decontamination and maintenance at the potential Yucca Mountain repository; Yucca Mountain Site characterization project

    SciTech Connect

    Hartman, D.J.; Miller, D.D.; Hill, R.R.

    1992-04-01

    This study investigates spent fuel cask handling experience at existing nuclear facilities to determine appropriate cask decontamination and maintenance operations at the potential Yucca Mountain repository. These operations are categorized as either routine or nonroutine. Routine cask decontamination and maintenance tasks are performed in the cask preparation area at the repository. Casks are taken offline to a separate cask maintenance area for major nonroutine tasks. The study develops conceptual designs of the cask preparation area and cask maintenance area. The functions, layouts, and major features of these areas are also described.

  3. Mechanical excavator performance in Yucca Mountain tuffs

    SciTech Connect

    Ozdemir, L.; Hansen, F.D.

    1991-01-01

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

  4. Mechanical excavator performance in Yucca Mountain tuffs

    SciTech Connect

    Ozdemir, L.; Hansen, F.D.

    1991-12-31

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

  5. Mechanical anisotropy of the Yucca Mountain tuffs

    SciTech Connect

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

    1991-12-31

    Three series of measurements were performed on oriented cores of several Yucca Mountain tuffs to determine the importance of mechanical anisotropy in the intact rock. Outcrop and drillhole samples were tested for acoustic velocities, linear compressibilities, and strengths in different orientations. The present data sets are preliminary, but suggest the tuffs are transversely anisotropic for these mechanical properties. The planar fabric that produces the anisotropy is believed to be predominantly the result of the preferred orientation of shards and pumice fragments. The potential of significant anisotropy has direct relevance to the formulation of constitutive formulation and the analyses of an underground opening within the Yucca Mountain.

  6. Two-dimensional velocity models for paths from Pahute Mesa and Yucca Flat to Yucca Mountain; Yucca Mountain Project

    SciTech Connect

    Walck, M.C.; Phillips, J.S.

    1990-11-01

    Vertical acceleration recordings of 21 underground nuclear explosions recorded at stations at Yucca Mountain provide the data for development of three two-dimensional crystal velocity profiles for portions of the Nevada Test Site. Paths from Area 19, Area 20 (both Pahute Mesa), and Yucca Flat to Yucca Mountain have been modeled using asymptotic ray theory travel time and synthetic seismogram techniques. Significant travel time differences exist between the Yucca Flat and Pahute Mesa source areas; relative amplitude patterns at Yucca Mountain also shift with changing source azimuth. The three models, UNEPM1, UNEPM2, and UNEYF1, successfully predict the travel time and amplitude data for all three paths. 24 refs., 34 figs., 8 tabs.

  7. Characterize Eruptive Processes at Yucca Mountain, Nevada

    SciTech Connect

    D. Krier

    2004-10-04

    The purpose of this scientific analysis report, ''Characterize Eruptive Processes at Yucca Mountain, Nevada'', is to present information about natural volcanic systems and the parameters that can be used to model their behavior. This information is used to develop parameter-value distributions appropriate for analysis of the consequences of volcanic eruptions through a repository at Yucca Mountain. This scientific analysis report provides information to four other reports: ''Number of Waste Packages Hit by Igneous Intrusion'', (BSC 2004 [DIRS 170001]); ''Atmospheric Dispersal and Deposition of Tephra from Potential Volcanic Eruption at Yucca Mountain, Nevada'' (BSC 2004 [DIRS 170026]); ''Dike/Drift Interactions'' (BSC 2004 [DIRS 170028]); ''Development of Earthquake Ground Motion Input for Preclosure Seismic Design and Postclosure Performance Assessment of a Geologic Repository at Yucca Mountain, NV'' (BSC 2004 [DIRS 170027], Section 6.5). This report is organized into seven major sections. This section addresses the purpose of this document. Section 2 addresses quality assurance, Section 3 the use of software, Section 4 identifies the requirements that constrain this work, and Section 5 lists assumptions and their rationale. Section 6 presents the details of the scientific analysis and Section 7 summarizes the conclusions reached.

  8. YUCCA MOUNTAIN WASTE PACKAGE CLOSURE SYSTEM

    SciTech Connect

    G. Housley; C. Shelton-davis; K. Skinner

    2005-08-26

    The method selected for dealing with spent nuclear fuel in the US is to seal the fuel in waste packages and then to place them in an underground repository at the Yucca Mountain Site in Nevada. This article describes the Waste Package Closure System (WPCS) currently being designed for sealing the waste packages.

  9. Fluid geochemistry of Yucca Mountain and vicinity

    USGS Publications Warehouse

    Marshall, Brian D.; Moscati, Richard J.; Patterson, Gary L.

    2012-01-01

    Yucca Mountain, a site in southwest Nevada, has been proposed for a deep underground radioactive waste repository. An extensive database of geochemical and isotopic characteristics has been established for pore waters and gases from the unsaturated zone, perched water, and saturated zone waters in the Yucca Mountain area. The development of this database has been driven by diverse needs of the Yucca Mountain Project, especially those aspects of the project involving process modeling and performance assessment. Water and gas chemistries influence the sorption behavior of radionuclides and the solubility of the radionuclide compounds that form. The chemistry of waters that may infiltrate the proposed repository will be determined in part by that of water present in the unsaturated zone above the proposed repository horizon, whereas pore-water compositions beneath the repository horizon will influence the sorption behavior of the radionuclides transported toward the water table. However, more relevant to the discussion in this chapter, development and testing of conceptual flow and transport models for the Yucca Mountain hydrologic system are strengthened through the incorporation of natural environmental tracer data into the process. Chemical and isotopic data are used to establish bounds on key hydrologic parameters and to provide corroborative evidence for model assumptions and predictions. Examples of specific issues addressed by these data include spatial and temporal variability in net fluxes, the role of faults in controlling flow paths, fracture-matrix interactions, the age and origin of perched water, and the distribution of water traveltimes.

  10. Preparing to Submit a License Application for Yucca Mountain

    SciTech Connect

    W.J. Arthur; M.D. Voegele

    2005-03-14

    In 1982, the U.S. Congress passed the Nuclear Waste Policy Act, a Federal law that established U.S. policy for the permanent disposal of spent nuclear fuel and high-level radioactive waste. Congress amended the Act in 1987, directing the Department of Energy to study only Yucca Mountain, Nevada as the site for a permanent geologic repository. As the law mandated, the Department evaluated Yucca Mountain to determine its suitability as the site for a permanent geologic repository. Decades of scientific studies demonstrated that Yucca Mountain would protect workers, the public, and the environment during the time that a repository would be operating and for tens of thousands of years after closure of the repository. A repository at this remote site would also: preserve the quality of the environment; allow the environmental cleanup of Cold War weapons facilities; provide the nation with additional protection from acts of terrorism; and support a sound energy policy. Throughout the scientific evaluation of Yucca Mountain, there has been no evidence to disqualify Yucca Mountain as a suitable site for the permanent disposal of spent nuclear fuel and high-level radioactive waste. Upon completion of site characterization, the Secretary of Energy considered the results and concluded that a repository at Yucca Mountain would perform in a manner that protects public health and safety. The Secretary recommended the site to the President in February 2002; the President agreed and recommended to Congress that the site be approved. The Governor of Nevada submitted a notice of disapproval, and both houses of Congress acted to override the disapproval. In July 2002, the President's approval allowed the Department to begin the process of submittal of a license application for Yucca Mountain as the site for the nation's first repository for spent nuclear fuel and high-level radioactive waste. Yucca Mountain is located on federal land in Nye County in southern Nevada, an arid region

  11. Geophysical expression of the Ghost Dance fault, Yucca Mountain, Nevada

    USGS Publications Warehouse

    Ponce, D.A.; Langenheim, V.E.

    1995-01-01

    Gravity and ground magnetic data collected along surveyed traverses across Antler and Live Yucca Ridges, on the eastern flank of Yucca Mountain, Nevada, reveal small-scale faulting associated with the Ghost Dance and possibly other faults. These studies are part of an effort to evaluate faulting in the vicinity of a potential nuclear waste repository at Yucca Mountain.

  12. Geophysical expression of the Ghost Dance Fault, Yucca Mountain, Nevada

    SciTech Connect

    Ponce, D.A.; Langenheim, V.E.

    1995-12-01

    Gravity and ground magnetic data collected along surveyed traverses across Antler and Live Yucca Ridges, on the eastern flank of Yucca Mountain, Nevada, reveal small-scale faulting associated with the Ghost Dance and possibly other faults. These studies are part of an effort to evaluate faulting in the vicinity of a potential nuclear waste repository at Yucca Mountain.

  13. Extreme ground motions and Yucca Mountain

    USGS Publications Warehouse

    Hanks, Thomas C.; Abrahamson, Norman A.; Baker, Jack W.; Boore, David M.; Board, Mark; Brune, James N.; Cornell, C. Allin; Whitney, John W.

    2013-01-01

    Yucca Mountain is the designated site of the underground repository for the United States' high-level radioactive waste (HLW), consisting of commercial and military spent nuclear fuel, HLW derived from reprocessing of uranium and plutonium, surplus plutonium, and other nuclear-weapons materials. Yucca Mountain straddles the western boundary of the Nevada Test Site, where the United States has tested nuclear devices since the 1950s, and is situated in an arid, remote, and thinly populated region of Nevada, ~100 miles northwest of Las Vegas. Yucca Mountain was originally considered as a potential underground repository of HLW because of its thick units of unsaturated rocks, with the repository horizon being not only ~300 m above the water table but also ~300 m below the Yucca Mountain crest. The fundamental rationale for a geologic (underground) repository for HLW is to securely isolate these materials from the environment and its inhabitants to the greatest extent possible and for very long periods of time. Given the present climate conditions and what is known about the current hydrologic system and conditions around and in the mountain itself, one would anticipate that the rates of infiltration, corrosion, and transport would be very low—except for the possibility that repository integrity might be compromised by low-probability disruptive events, which include earthquakes, strong ground motion, and (or) a repository-piercing volcanic intrusion/eruption. Extreme ground motions (ExGM), as we use the phrase in this report, refer to the extremely large amplitudes of earthquake ground motion that arise at extremely low probabilities of exceedance (hazard). They first came to our attention when the 1998 probabilistic seismic hazard analysis for Yucca Mountain was extended to a hazard level of 10-8/yr (a 10-4/yr probability for a 104-year repository “lifetime”). The primary purpose of this report is to summarize the principal results of the ExGM research program

  14. Hydrologic characteristics of faults at Yucca Mountain, Nevada

    SciTech Connect

    Dickerson, Robert P.

    2001-04-29

    Yucca Mountain is under study as a potential site for underground storage of high-level radioactive waste, with the principle goal being the safe isolation of the waste from the accessible environment. This paper addresses the hydrogeologic characteristics of the fault zones at Yucca Mountain, focusing primarily on the central part of the mountain where the potential repository block is located.

  15. Academy issues report on Yucca Mountain

    NASA Astrophysics Data System (ADS)

    Bush, Susan

    The National Academy of Sciences released a report on April 13 concluding that Yucca Mountain, the proposed nuclear waste repository site located about 100 miles northwest of Las Vegas, Nev., is not at risk from groundwater infiltration. “There is no evidence to support the assertion that the water table has risen periodically hundreds of meters from deep within the crust,” the report states.According to vice chairman of the NAS panel George A. Thompson of Stanford University, the panel was charged with evaluating whether the water table has risen in the past to the level of the proposed repository or if this might happen in the future. The panel was not responsible for determining whether Yucca Mountain is suitable as a repository site.

  16. Rail Access to Yucca Mountain: Critical Issues

    SciTech Connect

    Halstead, R. J.; Dilger, F.; Moore, R. C.

    2003-02-25

    The proposed Yucca Mountain repository site currently lacks rail access. The nearest mainline railroad is almost 100 miles away. Absence of rail access could result in many thousands of truck shipments of spent nuclear fuel and high-level radioactive waste. Direct rail access to the repository could significantly reduce the number of truck shipments and total shipments. The U.S. Department of Energy (DOE) identified five potential rail access corridors, ranging in length from 98 miles to 323 miles, in the Final Environmental Impact Statement (FEIS) for Yucca Mountain. The FEIS also considers an alternative to rail spur construction, heavy-haul truck (HHT) delivery of rail casks from one of three potential intermodal transfer stations. The authors examine the feasibility and cost of the five rail corridors, and DOE's alternative proposal for HHT transport. The authors also address the potential for rail shipments through the Las Vegas metropolitan area.

  17. DOE`s Yucca Mountain studies

    SciTech Connect

    1992-12-01

    This booklet is about the disposal of high-level nuclear waste in the United States. It is for readers who have a general rather than a technical background. It discusses why scientists and engineers think high-level nuclear waste may be disposed of safely underground. It also describes why Yucca Mountain, Nevada, is being studied as a potential repository site and provides basic information about those studies.

  18. Predicting the Future at Yucca Mountain

    SciTech Connect

    J. R. Wilson

    1999-07-01

    This paper summarizes a climate-prediction model funded by the DOE for the Yucca Mountain nuclear waste repository. Several articles in the open literature attest to the effects of the Global Ocean Conveyor upon paleoclimate, specifically entrance and exit from the ice age. The data shows that these millennial-scale effects are duplicated on the microscale of years to decades. This work also identifies how man may have influenced the Conveyor, affecting global cooling and warming for 2,000 years.

  19. Yucca Mountain Project Surface Facilities Design

    SciTech Connect

    P.W. McDaniel; N.R. Brown; P.G. Harrington; J.T. Gardiner; L.J. Trautner

    2002-11-20

    With the recent designation of the Yucca Mountain site as a proposed repository for the disposal of commercial spent nuclear fuel, DOE spent nuclear fuel and high- level waste, work is proceeding on the design of surface facilities to receive, unload, and package the waste into waste packages for emplacement in the repository. This paper summarizes recent progress in the design of these surface facilities.

  20. Revised mineralogic summary of Yucca Mountain, Nevada

    SciTech Connect

    Bish, D.L.; Chipera, S.J.

    1989-03-01

    We have evaluated three-dimensional mineral distribution at Yucca Mountain, Nevada, using quantitative x-ray powder diffraction analysis. All data were obtained on core cuttings, or sidewall samples obtained from drill holes at and around Yucca Mountain. Previously published data are included with corrections, together with new data for several drill holes. The new data presented in this report used the internal standard method of quantitative analysis, which yields results of high precision for the phases commonly found in Yucca Mountain tuffs including opal-CT and glass. Mineralogical trends with depth previously noted are clearly shown by these new data. Glass occurrence is restricted almost without exception to above the present-day static water level (SWL), although glass has been identified below the SWL in partially zeolitized tuffs. Silica phases undergo well-defined transitions with depth, with tridymite and cristobalite occurring only above the SWL, opal-CT occurring with clinoptilolite-mordenite tuffs, and quartz most abundant below the SWL. Smectite occurs in small amounts in most samples but is enriched in two distinct zones. These zones are at the top of the vitric nonwelded base of the Tiva Canyon Member and at the top of the basal vitrophyre of the Topopah Spring Member. Our data support the presence of several zones of mordenite and clinoptilolite-heulandite as shown previously. New data on several deep clinoptililite-heulandite samples coexisting with analcime show that they are heulandite. Phillipsite has not been found in any Yucca Mountain samples, but erionite and chabazite have been found once in fractures. 21 refs., 17 figs.

  1. Use of thermal data to estimate infiltration, Yucca Mountain, Nevada

    SciTech Connect

    LeCain, Gary D.; Kurzmack, Mark

    2001-04-29

    Temperature and pressure monitoring in a vertical borehole in Pagany Wash, Yucca Mountain, Nevada, measured disruptions of the natural gradients associated with the February, 1998, El Nino precipitation events. The temperature and pressure disruptions indicated infiltration and percolation through the 12.1 m of Pagany Wash alluvium and deep percolation to greater than 35.2 m into the Yucca Mountain Tuff.

  2. The Occurrence of Erionite at Yucca Mountain

    SciTech Connect

    NA

    2004-07-01

    The naturally-occurring zeolite mineral erionite has a fibrous morphology and is a known human carcinogen (inhalation hazard). Erionite has been found typically in very small quantities and restricted occurrences in the course of mineralogic characterization of Yucca Mountain as a host for a high-level nuclear waste repository. The first identification of erionite was made in 1984 on the basis of morphology and chemical composition and later confirmed by X-ray diffraction analysis. It was found in the lower vitrophyre (Tptpv3) of the Topopah Spring Tuff in a borehole sidewall sample. Most erionite occurrences identified at Yucca Mountain are in the Topopah Spring Tuff, within an irregular zone of transition between the lower boundary of devitrified tuff and underlying glassy tuff. This zone is fractured and contains intermingled devitrified and vitric tuff. In 1997, a second host of erionite mineralization was identified in the Exploratory Studies Facility within and adjacent to a high-angle fracture/breccia zone transgressing the boundary between the lowermost devitrified tuff (Tpcplnc) and underlying moderately welded vitric tuff (Tpcpv2) of the Tiva Canyon Tuff. The devitrified-vitric transition zones where erionite is found tend to have complex secondary-mineral assemblages, some of very localized occurrence. Secondary minerals in addition to erionite may include smectite, heulandite-clinoptilolite, chabazite, opal-A, opal-CT, cristobalite, quartz, kenyaite, and moganite. Incipient devitrification within the Topopah Spring Tuff transition zone includes patches that are highly enriched in potassium feldspar relative to the precursor volcanic glass. Geochemical conditions during glass alteration may have led to local evolution of potassium-rich fluids. Thermodynamic modeling of zeolite stability shows that erionite and chabazite stability fields occur only at aqueous K concentrations much higher than in present Yucca Mountain waters. The association of erionite

  3. Mineralogic summary of Yucca Mountain, Nevada

    SciTech Connect

    Bish, D.L.; Vaniman, D.T.

    1985-10-01

    Quantitative x-ray powder diffraction analysis of tuffs and silicic lavas, using matrix-flushing techniques, has been used to obtain a model of three-dimensional mineral distributions at Yucca Mountain, Nevada. This method of analysis is especially useful in tuff, where the most abundant phases are commonly too fine grained for optical determination. The three-dimensional distributions of primary glass and of tridymite are particularly well constrained. Vitric nonwelded glasses occur above and below the welded devitrified Topopah Spring Member, but the glass in the lower nonwelded vitric zone is progressively altered to zeolites to the east where the zone is closer to the static water level. The zeolites clinoptilolite, mordenite, heulandite, and erionite have all been found at Yucca Mountain, but only mordenite and clinoptilolite are abundant and can be mapped between many drill holes and at many depths. Heulandite distribution is also mappable, but only below the densely welded devitrified part of the Topopah Storing Member. Erionite has been confirmed only once, as a fracture coating. There is a fairly continuous smectite-rich interval immediately above the basal vitrophyre of the Topopah Spring Member, but no evidence suggests that the smectites can provide information on the paleogroundwater table. There are at least four mappable zeolitized zones in Yucca Mountain, and the thicker zones tend to coincide with intervals that retained glass following early tuff devitrification. Problems in extrapolation occur where zones of welding pinch out. No phillipsite has been found, and some samples previously reported to contain phillipsite or erionite were reexamined with negative results. The deeper alteration to albite and analcime was not sampled in every drill hole, and the distribution of these phases is difficult to map.

  4. Room at the Mountain: Estimated Maximum Amounts of Commercial Spent Nuclear Fuel Capable of Disposal in a Yucca Mountain Repository

    SciTech Connect

    Kessler, John H.; Kemeny, John; King, Fraser; Ross, Alan M.; Ross, Benjamen

    2006-07-01

    The purpose of this paper is to present an initial analysis of the maximum amount of commercial spent nuclear fuel (CSNF) that could be emplaced into a geological repository at Yucca Mountain. This analysis identifies and uses programmatic, material, and geological constraints and factors that affect this estimation of maximum amount of CSNF for disposal. The conclusion of this initial analysis is that the current legislative limit on Yucca Mountain disposal capacity, 63,000 MTHM of CSNF, is a small fraction of the available physical capacity of the Yucca Mountain system assuming the current high-temperature operating mode (HTOM) design. EPRI is confident that at least four times the legislative limit for CSNF ({approx}260,000 MTHM) can be emplaced in the Yucca Mountain system. It is possible that with additional site characterization, upwards of nine times the legislative limit ({approx}570,000 MTHM) could be emplaced. (authors)

  5. Overview of the Yucca Mountain Licensing Process

    SciTech Connect

    M. Wisenburg

    2004-05-03

    This paper presents an overview of the licensing process for a Yucca Mountain repository for high-level radioactive waste and spent nuclear fuel. The paper discusses the steps in the licensing proceeding, the roles of the participants, the licensing and hearing requirements contained in the Code of Federal Regulations. A description of the Nuclear Regulatory Commission (NRC) staff acceptance and compliance reviews of the Department of Energy (DOE) application for a construction authorization and a license to receive and possess high-level radioactive waste and spent nuclear fuel is provided. The paper also includes a detailed description of the hearing process.

  6. Tunneling progress on the Yucca Mountain Project

    SciTech Connect

    Hansmire, W.H.; Munzer, R.J.

    1996-06-01

    The current status of tunneling progress on the Yucca Mountain Project (YMP) is presented in this paper. The Exploratory Studies Facility (ESF), a key part of the YMP, has been long in development and construction is ongoing. This is a progress report on the tunneling aspects of the ESF as of January 1, 1996. For purposes of discussion in this summary, the tunneling has progressed in four general phases. The paper describes: tunneling in jointed rock under low stress; tunneling through the Bow Ridge Fault and soft rock; tunneling through the Imbricate Fault Zone; and Tunneling into the candidate repository formation.

  7. Magma Dynamics at Yucca Mountain, Nevada

    SciTech Connect

    D. Krier

    2005-08-29

    Small-volume basaltic volcanic activity at Yucca Mountain has been identified as one of the potential events that could lead to release of radioactive material from the U.S. Department of Energy (DOE) designated nuclear waste repository at Yucca Mountain. Release of material could occur indirectly as a result of magmatic dike intrusion into the repository (with no associated surface eruption) by changing groundwater flow paths, or as a result of an eruption (dike intrusion of the repository drifts, followed by surface eruption of contaminated ash) or volcanic ejection of material onto the Earth's surface and the redistribution of contaminated volcanic tephra. Either release method includes interaction between emplacement drifts and a magmatic dike or conduit, and natural (geologic) processes that might interrupt or halt igneous activity. This analysis provides summary information on two approaches to evaluate effects of disruption at the repository by basaltic igneous activity: (1) descriptions of the physical geometry of ascending basaltic dikes and their interaction with silicic host rocks similar in composition to the repository host rocks; and (2) a summary of calculations developed to quantify the response of emplacement drifts that have been flooded with magma and repressurized following blockage of an eruptive conduit. The purpose of these analyses is to explore the potential consequences that could occur during the full duration of an igneous event.

  8. Practical postcalibration uncertainty analysis: Yucca Mountain, Nevada.

    PubMed

    James, Scott C; Doherty, John E; Eddebbarh, Al-Aziz

    2009-01-01

    The values of parameters in a groundwater flow model govern the precision of predictions of future system behavior. Predictive precision, thus, typically depends on an ability to infer values of system properties from historical measurements through calibration. When such data are scarce, or when their information content with respect to parameters that are most relevant to predictions of interest is weak, predictive uncertainty may be high, even if the model is "calibrated." Recent advances help recognize this condition, quantitatively evaluate predictive uncertainty, and suggest a path toward improved predictive accuracy by identifying sources of predictive uncertainty and by determining what observations will most effectively reduce this uncertainty. We demonstrate linear and nonlinear predictive error/uncertainty analyses as applied to a groundwater flow model of Yucca Mountain, Nevada, the United States' proposed site for disposal of high-level radioactive waste. Linear and nonlinear uncertainty analyses are readily implemented as an adjunct to model calibration with medium to high parameterization density. Linear analysis yields contributions made by each parameter to a prediction's uncertainty and the worth of different observations, both existing and yet-to-be-gathered, toward reducing this uncertainty. Nonlinear analysis provides more accurate characterization of the uncertainty of model predictions while yielding their (approximate) probability distribution functions. This article applies the above methods to a prediction of specific discharge and confirms the uncertainty bounds on specific discharge supplied in the Yucca Mountain Project License Application. PMID:19744249

  9. Seismic monitoring of the Yucca Mountain facility

    SciTech Connect

    Garbin, H.D.; Herrington, P.B.; Kromer, R.P.

    1997-08-01

    Questions have arisen regarding the applicability of seismic sensors to detect mining (re-entry) with a tunnel boring machine (TBM). Unlike cut and blast techniques of mining which produce impulsive seismic signals, the TBM produces seismic signals which are of long duration. (There are well established techniques available for detecting and locating the sources of the impulsive signals.) The Yucca Mountain repository offered an opportunity to perform field evaluations of the capabilities of seismic sensors because during much of 1996, mining there was progressing with the use of a TBM. During the mining of the repository`s southern branch, an effort was designed to evaluate whether the TBM could be detected, identified and located using seismic sensors. Three data acquisition stations were established in the Yucca Mountain area to monitor the TBM activity. A ratio of short term average to long term average algorithm was developed for use in signal detection based on the characteristics shown in the time series. For location of the source of detected signals, FK analysis was used on the array data to estimate back azimuths. The back azimuth from the 3 component system was estimated from the horizontal components. Unique features in the timing of the seismic signal were used to identify the source as the TBM.

  10. TBM tunneling on the Yucca Mountain Project

    SciTech Connect

    Morris, J.P.; Hansmire, W.H. |

    1995-03-01

    The US Department of Energy`s (DOE) Yucca Mountain Project (YMP) is a scientific endeavor to determine the suitability of Yucca Mountain for the first long-term, high-level nuclear waste repository in the United States. The current status of this long-term project from the construction perspective is described. A key element is construction of the Exploratory Studies Facility (ESF) Tunnel, which is being excavated with a 7.6 m (25 ft) diameter tunnel boring machine (TBM). Development of the ESF may include the excavation of over 15 km (9.3 mi) of tunnel varying in size from 3.0 to 7.6 m (10 to 25 ft). Prior to construction, extensive constructability reviews were an interactive part of the final design. The intent was to establish a constructable design that met the long-term stability requirements for radiological safety of a future repository, while maintaining flexibility for the scientific investigations and acceptable tunneling productivity.

  11. Using science soundly: The Yucca Mountain standard

    SciTech Connect

    Fri, R.W.

    1995-09-01

    Using sound science to shape government regulation is one of the most hotly argued topics in the ongoing debate about regulatory reform. Even though no one advaocates using unsound science, the belief that even the best science will sweep away regulatory controversy is equally foolish. As chair of a National Research Council (NRC) committee that studied the scientific basis for regulating high-level nuclear waste disposal, the author learned that science alone could resolve few of the key regulatory questions. Developing a standard that specifies a socially acceptable limit on the human health effects of nuclear waste releases involves many decisions. As the NRC committee learned in evaluating the scientific basis for the Yucca Mountain standard, a scientifically best decision rarely exists. More often, science can only offer a useful framework and starting point for policy debates. And sometimes, science`s most helpful contribution is to admit that it has nothing to say. The Yucca mountain study clearly illustrates that excessive faith in the power of science is more likely to produce messy frustration than crisp decisions. A better goal for regulatory reform is the sound use of science to clarify and contain the inevitable policy controversy.

  12. Yucca Mountain drift scale test progress report

    SciTech Connect

    Apps, J.; Birkholzer, J.T.; Peterson,J.E.; Sonnenthal, E.; Spycher, N.; Tsang, Y.W.; Williams, K.H.

    1999-01-01

    The Drift Scale Test (DST) is part of the Exploratory Studies Facility (ESF) Thermal Test being conducted underground at the potential high-level nuclear waste repository at Yucca Mountain, Nevada. The purpose of the ESF Thermal Test is to acquire a more in-depth understanding of the coupled thermal, mechanical, hydrological, and chemical processes likely to be encountered in the rock mass surrounding the potential geological repository at Yucca Mountain. These processes are monitored by a multitude of sensors to measure the temperature, humidity, gas pressure, and mechanical displacement, of the rock formation in response to the heat generated by the heaters. In addition to collecting passive monitoring data, active hydrological and geophysical testing is also being carried out periodically in the DST. These active tests are intended to monitor changes in the moisture redistribution in the rock mass, to collect water and gas samples for chemical and isotopic analysis, and to detect microfiacturing due to heating. On December 3, 1998, the heaters in the DST were activated. The planned heating phase of the DST is 4 years, and the cooling phase following the power shutoff will be of similar duration. The present report summarizes interpretation and analysis of thermal, hydrological, chemical, and geophysical data for the first 6 months; it is the first of many progress reports to be prepared during the DST.

  13. Examining Repository Loading Options to Expand Yucca Mountain Repository Capacity

    SciTech Connect

    Li, Jun; Nicholson, Mark; Proctor, W. Cyrus; Yim, Man-Sung; McNelis, David

    2007-07-01

    researchers. This paper investigates options (3) and (4) for possible expansion of the Yucca Mountain repository capacity. To support the work, a thermal analysis model was needed to describe the temperature changes in the rock around the waste packages against the thermal design limits as a function of spent fuel characteristics and composition. Under the high temperature operating mode (HTOM), the relevant thermal design limits are: (1) the rock temperature midway between adjacent drifts must remain below the local boiling point (96 deg. C); and (2) the rock temperature at drift walls must remain below 200 deg. C. As the work involves a large number of calculations, examining the compliance within thermal design limits, the capability to perform efficient mountain-scale heat-transfer analyses was necessary. A related topic of importance in this investigation was also the effect of uncertainty. As the modeling exercise relies on the use of computational models, uncertainties are unavoidable and understanding the uncertainty in the interpretation of the results is important. The concept of variable drift spacing and variable drift thermal loading was investigated with respect to possible capacity expansion of the Yucca Mountain repository. Also, a computer model was developed for efficient repository heat transfer calculations and sensitivity and uncertainty analyses were performed to identify key parameters and to estimate the uncertainty in the results and understand how the repository capacity estimation would be affected by the uncertainty. (authors)

  14. Selection of Batteries and Fuel Cells for Yucca Mountain Robots

    SciTech Connect

    Upadhye, R S

    2003-12-08

    The Performance Confirmation program of the Yucca Mountain Repository Development Project needs to employ remotely operated robots to work inside the emplacement drifts which will have an environment unsuitable for humans (radiation environment of up to 200 rad/hour (mostly gamma rays, some neutrons)) and maximum temperatures of 180 C. The robots will be required to operate inside the drifts for up to 8 hours per mission. Based on available functional requirements, we have developed the following specifications for the power needed by the robots:

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

    SciTech Connect

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

    1985-11-01

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

  16. Effects of a potential drop of a shipping cask, a waste container, and a bare fuel assembly during waste-handling operations; Yucca Mountain Site Characterization Project

    SciTech Connect

    Wu, C.L.; Lee, J.; Lu, D.L.; Jardine, L.J.

    1991-12-01

    This study investigates the effects of potential drops of a typical shipping cask, waste container, and bare fuel assembly during waste-handling operations at the prospective Yucca Mountain Repository. The waste-handling process (one stage, no consolidation configuration) is examined to estimate the maximum loads imposed on typical casks and containers as they are handled by various pieces of equipment during waste-handling operations. Maximum potential drop heights for casks and containers are also evaluated for different operations. A nonlinear finite-element model is employed to represent a hybrid spent fuel container subject to drop heights of up to 30 ft onto a reinforced concrete floor. The impact stress, strain, and deformation are calculated, and compared to the failure criteria to estimate the limiting (maximum permissible) drop height for the waste container. A typical Westinghouse 17 {times} 17 PWR fuel assembly is analyzed by a simplified model to estimate the energy absorption by various parts of the fuel assembly during a 30 ft drop, and to determine the amount of kinetic energy in a fuel pin at impact. A nonlinear finite-element analysis of an individual fuel pin is also performed to estimate the amount of fuel pellet fracture due to impact. This work was completed on May 1990.

  17. Preparing the Yucca Mountain Multimedia Presentation

    SciTech Connect

    Y. Larkin; J. Hartley; J. Scott

    2002-11-14

    In July 2002, the U.S. Congress approved Yucca Mountain in Nevada for development as a geologic repository for spent nuclear fuel and high-level radioactive waste. This major milestone for the country's high-level radioactive waste disposal program comes after more than 20 years of scientific study and intense public interaction and outreach. The U.S. Department of Energy's (DOE) public involvement activities were driven by two federal regulations-the National Environmental Policy Act (NEPA) and the Nuclear Waste Policy Act (NWPA) of 1982, as amended. The NEPA required that DOE hold public hearings at key points in the development of an Environmental Impact Statement (EIS) and the NWPA required the agency to conduct public hearings in the vicinity of the site prior to making a recommendation regarding the site's suitability. The NWPA also provided a roadmap for how DOE would interact with affected units of government, which include the state of Nevada and the counties surrounding the site. As the Project moves into the next phase--applying for a license to construct a repository-the challenge of public interaction and outreach remains. It has become increasingly important to provide tools to communicate to the public the importance of the Yucca Mountain Project. Sharing the science and engineering research with the general public, as well as teachers, students, and industry professionals, is one of the project's most important activities. Discovering ways to translate project information and communicate this information to local governments, agencies, citizens' groups, schools, the news media, and other stakeholders is critical. With these facts in mind, the authors set out to create a presentation that would bring the ''mountain'' to the public.

  18. Statistical analysis of hydrologic data for Yucca Mountain; Yucca Mountain Site Characterization Project

    SciTech Connect

    Rutherford, B.M.; Hall, I.J.; Peters, R.R.; Easterling, R.G.; Klavetter, E.A.

    1992-02-01

    The geologic formations in the unsaturated zone at Yucca Mountain are currently being studied as the host rock for a potential radioactive waste repository. Data from several drill holes have been collected to provide the preliminary information needed for planning site characterization for the Yucca Mountain Project. Hydrologic properties have been measured on the core samples and the variables analyzed here are thought to be important in the determination of groundwater travel times. This report presents a statistical analysis of four hydrologic variables: saturated-matrix hydraulic conductivity, maximum moisture content, suction head, and calculated groundwater travel time. It is important to modelers to have as much information about the distribution of values of these variables as can be obtained from the data. The approach taken in this investigation is to (1) identify regions at the Yucca Mountain site that, according to the data, are distinctly different; (2) estimate the means and variances within these regions; (3) examine the relationships among the variables; and (4) investigate alternative statistical methods that might be applicable when more data become available. The five different functional stratigraphic units at three different locations are compared and grouped into relatively homogeneous regions. Within these regions, the expected values and variances associated with core samples of different sizes are estimated. The results provide a rough estimate of the distribution of hydrologic variables for small core sections within each region.

  19. The Yucca Mountain Project drift scale test

    SciTech Connect

    Finley, R.E.; Blair, S.C.; Boyle, W.J.

    1998-06-01

    The Yucca Mountain Project is currently evaluating the coupled thermal-mechanical-hydrological-chemical (TMHC) response of the potential repository host rock through an in situ thermal testing program. A drift scale test (DST) was constructed during 1997 and heaters were turned on in December 1997. The DST includes nine canister-sized containers with thirty operating heaters each located within the heated drift (HD) and fifty wing heaters located in boreholes in both ribs with a total power output of nominally 210kW. A total of 147 boreholes (combined length of 3.3 km) houses most of the over 3700 TMHC sensors connected with 201 km of cabling to a central data acquisition system. The DST is located in the Exploratory Studies Facility in a 5-m diameter drift approximately 50 m in length. Heating will last up to four years and cooling will last another four years. The rock mass surrounding the DST will experience a harsh thermal environment with rock surface temperatures expected to reach a maximum of about 200 C. This paper describes the process of designing the DST. The first 38 m of the 50-m long Heated Drift (HD) is dedicated to collection of data that will lead to a better understanding of the complex coupled TMHC processes in the host rock of the proposed repository. The final 12 m is dedicated to evaluating the interactions between the heated rock mass and cast-in-place (CIP) concrete ground support systems at elevated temperatures. In addition to a description of the DST design, data from site characterization, and a general description of the analyses and analysis approach used to design the test and make pretest predictions are presented. Test-scoping and pretest numerical predictions of one way thermal-hydrologic, thermal-mechanical, and thermal-chemical behaviors have been completed (TRW, 1997a). These analyses suggest that a dry-out zone will be created around the DST and a 10,000 m{sup 3} volume of rock will experience temperatures above 100 C. The HD

  20. Tectonic and neotectonic framework of the Yucca Mountain Region

    SciTech Connect

    Schweickert, R.A.

    1992-09-30

    Highlights of major research accomplishments concerned with the tectonics and neotectonics of the Yucca Mountain Region include: structural studies in Grapevine Mountains, Bullfrog Hills, and Bare Mountain; recognition of significance of pre-Middle Miocene normal and strike-slip faulting at Bare Mountain; compilation of map of quaternary faulting in Southern Amargosa Valley; and preliminary paleomagnetic analysis of Paleozoic and Cenozoic units at Bare Mountain.

  1. Characterize Eruptive Processes at Yucca Mountain, Nevada

    SciTech Connect

    G. Valentine

    2001-12-20

    This Analysis/Model Report (AMR), ''Characterize Eruptive Processes at Yucca Mountain, Nevada'', presents information about natural volcanic systems and the parameters that can be used to model their behavior. This information is used to develop parameter-value distributions appropriate for analysis of the consequences of volcanic eruptions through a potential repository at Yucca Mountain. Many aspects of this work are aimed at resolution of the Igneous Activity Key Technical Issue (KTI) as identified by the Nuclear Regulatory Commission (NRC 1998, p. 3), Subissues 1 and 2, which address the probability and consequence of igneous activity at the proposed repository site, respectively. Within the framework of the Disruptive Events Process Model Report (PMR), this AMR provides information for the calculations in two other AMRs ; parameters described herein are directly used in calculations in these reports and will be used in Total System Performance Assessment (TSPA). Compilation of this AMR was conducted as defined in the Development Plan, except as noted. The report begins with considerations of the geometry of volcanic feeder systems, which are of primary importance in predicting how much of a potential repository would be affected by an eruption. This discussion is followed by one of the physical and chemical properties of the magmas, which influences both eruptive styles and mechanisms for interaction with radioactive waste packages. Eruptive processes including the ascent velocity of magma at depth, the onset of bubble nucleation and growth in the rising magmas, magma fragmentation, and velocity of the resulting gas-particle mixture are then discussed. The duration of eruptions, their power output, and mass discharge rates are also described. The next section summarizes geologic constraints regarding the interaction between magma and waste packages. Finally, they discuss bulk grain size produced by relevant explosive eruptions and grain shapes.

  2. The Pahrump Valley Museum Yucca Mountain History Exhibit - 12389

    SciTech Connect

    Voegele, Michael; McCracken, Robert; Herrera, Troy

    2012-07-01

    As part of its management of the Yucca Mountain project, the Department of Energy maintained several information centers to provide public access to information about the status of the Yucca Mountain project. Those information centers contained numerous displays, historical information, and served as the location for the Department's outreach activities. As the Department of Energy dealt with reduced budgets in 2009 following the Obama Administration's intent to terminate the program, it shut down its information centers. Nye County considered it important to maintain a public information center where people would be able to find information about what was happening with the Yucca Mountain project. Initially the Nye County assumed responsibility for the information center in Pahrump; eventually the County made a decision to move that information center into an expansion of the existing Pahrump Valley Museum. Nye County undertook an effort to update the information about the Yucca Mountain project and modernize the displays. A parallel effort to create a source of historical information where people could find out about the Yucca Mountain project was undertaken. To accompany the Yucca Mountain exhibits in the Pahrump Valley Museum, Nye County also sponsored a series of interviews to document, through oral histories, as much information about the Yucca Mountain project as could be found in these interviews. The paper presents an overview of the Yucca Mountain exhibits in the Pahrump Valley Museum, and the accompanying oral histories. An important conclusion that can be drawn from the interviews is that construction of a repository in Nevada should have been conceptualized as but the first step in transforming the economy of central Nevada by turning part of the Nevada National Security Site and adjoining area into a world-class energy production and energy research center. (authors)

  3. Preliminary mapping of surficial geology of Midway Valley Yucca Mountain Project, Nye County, Nevada; Yucca Mountain Site Characterization Project

    SciTech Connect

    Wesling, J.R.; Bullard, T.F.; Swan, F.H.; Perman, R.C.; Angell, M.M.; Gibson, J.D.

    1992-04-01

    The tectonics program for the proposed high-level nuclear waste repository at Yucca Mountain in southwestern Nevada must evaluate the potential for surface faulting beneath the prospective surface facilities. To help meet this goal, Quaternary surficial mapping studies and photolineament analyses were conducted to provide data for evaluating the location, recency, and style of faulting with Midway Valley at the eastern base of Yucca Mountain, the preferred location of these surface facilities. This interim report presents the preliminary results of this work.

  4. Transport of radon gas into a tunnel at Yucca Mountain--estimating large-scale fractured tuff hydraulic properties and implications for the operation of the ventilation system.

    PubMed

    Unger, André; Finsterle, Stefan; Bodvarsson, Gudmundur

    2004-06-01

    Radon gas concentrations have been monitored as part of the operation of a tunnel (the Exploratory Studies Facility-ESF) at Yucca Mountain to ensure worker safety. The objective of this study was to examine the potential use of the radon data to estimate large-scale formation properties of fractured tuffs. This objective was examined by developing a numerical model, based upon the characteristics of the ESF and the Topopah Spring welded (TSw) tuff unit, capable of predicting radon concentrations for prescribed ventilation conditions. The model was used to address two specific issues. First, it was used to estimate the permeability and porosity of the fractures in the TSw at the length scale of the ESF and extending tens of meters into the TSw, which surrounds the ESF. Second, the model was used to understand the mechanism leading to radon concentrations exceeding a specified level within the ESF. The mechanism controlling radon concentrations in the ESF is a function of atmospheric barometric fluctuations being propagated down the ESF along with ventilated air flow and the slight suction induced by the ventilation exhaust fans at the South Portal of the ESF. These pressure fluctuations are dampened in the TSw fracture continuum according to its permeability and porosity. Consequently, as the barometric pressure in the ESF drops rapidly, formation gases from the TSw are pulled into the ESF, resulting in an increase in radon concentrations. Model calibration to both radon concentrations measured in the ESF and gas-phase pressure fluctuations in the TSw yielded concurrent estimates of TSw fracture permeability and porosity of 1 x 10(-11) m2 and 0.00034, respectively. The calibrated model was then used as a design tool to predict the effect of adjusting the current ventilation-system operation strategy for reducing the probability of radon gas concentrations exceeding a specified level. PMID:15134873

  5. Transport of Radon Gas into a Tunnel at Yucca Mountain-Estimating Large-Scale Fractured Tuff Hydraulic Properties and Implications for the Operation of the Ventilation System

    SciTech Connect

    A. Unger; S. Finsterle; G. Bodvarsson

    2003-06-06

    Radon gas concentrations have been monitored as part of the operation of a tunnel (the Exploratory Studies Facility-ESF) at Yucca Mountain to ensure worker safety. The objective of this study was to examine the potential use of the radon data to estimate large-scale formation properties of fractured tuffs. This objective was examined by developing a numerical model, based upon the characteristics of the ESF and the Topopah Spring welded (TSw) tuff unit, capable of predicting radon concentrations for prescribed ventilation conditions. The model was used to address two specific issues. First, it was used to estimate the permeability and porosity of the fractures in the TSw at the length scale of the ESF and extending tens of meters into the TSw, which surrounds the ESF. Second, the model was used to understand the mechanism leading to radon concentrations exceeding a specified level within the ESF. The mechanism controlling radon concentrations in the ESF is a function of atmospheric barometric fluctuations being propagated down the ESF along with ventilated air flow and the slight suction induced by the ventilation exhaust fans at the South Portal of the ESF. These pressure fluctuations are dampened in the TSw fracture continuum according to its permeability and porosity. Consequently, as the barometric pressure in the ESF drops rapidly, formation gases from the TSw are pulled into the ESF, resulting in an increase in radon concentrations. Model calibration to both radon concentrations measured in the ESF and gas-phase pressure fluctuations in the TSw yielded concurrent estimates of TSw fracture permeability and porosity of l x 10{sup -11} m{sup 2} and 0.00034, respectively. The calibrated model was then used as a design tool to predict the effect of adjusting the current ventilation-system operation strategy for reducing the probability of radon gas concentrations exceeding a specified level.

  6. Defining the potential repository siting block Yucca Mountain, Nevada

    SciTech Connect

    Elayer, R.W.; Nolting, R.M. III

    1996-12-01

    Siting activities for the potential high-level nuclear waste repository at Yucca Mountain focused on locating a suitable host geologic horizon above the water table. The Topopah Spring Tuff of the Paintbrush Group was identified as the most suitable geologic unit. Sandia National Laboratories (Sandia) identified six areas as potential repository sites. Area known as the Primary Area, is the site of the present characterization and design activities. To support current repository Advanced Conceptual Design, a reevaluation of the Primary Area was conducted by the Yucca Mountain Project`s Management and Operating Contractor (M&O). The purpose of the study was to more precisely define the block volume that would be suitable for siting the repository. The Lynx Geoscience Modeling software (Lynx) was selected to be used in this work because of its three-dimensional modeling and visualization capability for geology and underground excavation design. The Lynx model YMP.MO2 was developed in the study. The model includes surfaces that were constructed to represent each of the following limiting criteria: faults, overburden, repository host horizon, and groundwater. The resulting potential repository siting block is the useable volume within these limiting criteria.

  7. Estimating recharge at Yucca Mountain, Nevada, USA: comparison of methods

    NASA Astrophysics Data System (ADS)

    Flint, Alan L.; Flint, Lorraine E.; Kwicklis, Edward M.; Fabryka-Martin, June T.; Bodvarsson, Gudmundur S.

    2002-02-01

    Obtaining values of net infiltration, groundwater travel time, and recharge is necessary at the Yucca Mountain site, Nevada, USA, in order to evaluate the expected performance of a potential repository as a containment system for high-level radioactive waste. However, the geologic complexities of this site, its low precipitation and net infiltration, with numerous mechanisms operating simultaneously to move water through the system, provide many challenges for the estimation of the spatial distribution of recharge. A variety of methods appropriate for arid environments has been applied, including water-balance techniques, calculations using Darcy's law in the unsaturated zone, a soil-physics method applied to neutron-hole water-content data, inverse modeling of thermal profiles in boreholes extending through the thick unsaturated zone, chloride mass balance, atmospheric radionuclides, and empirical approaches. These methods indicate that near-surface infiltration rates at Yucca Mountain are highly variable in time and space, with local (point) values ranging from zero to several hundred millimeters per year. Spatially distributed net-infiltration values average 5 mm/year, with the highest values approaching 20 mm/year near Yucca Crest. Site-scale recharge estimates range from less than 1 to about 12 mm/year. These results have been incorporated into a site-scale model that has been calibrated using these data sets that reflect infiltration processes acting on highly variable temporal and spatial scales. The modeling study predicts highly non-uniform recharge at the water table, distributed significantly differently from the non-uniform infiltration pattern at the surface.

  8. Estimating recharge at Yucca Mountain, Nevada, USA: Comparison of methods

    USGS Publications Warehouse

    Flint, A.L.; Flint, L.E.; Kwicklis, E.M.; Fabryka-Martin, J. T.; Bodvarsson, G.S.

    2002-01-01

    Obtaining values of net infiltration, groundwater travel time, and recharge is necessary at the Yucca Mountain site, Nevada, USA, in order to evaluate the expected performance of a potential repository as a containment system for high-level radioactive waste. However, the geologic complexities of this site, its low precipitation and net infiltration, with numerous mechanisms operating simultaneously to move water through the system, provide many challenges for the estimation of the spatial distribution of recharge. A variety of methods appropriate for arid environments has been applied, including water-balance techniques, calculations using Darcy's law in the unsaturated zone, a soil-physics method applied to neutron-hole water-content data, inverse modeling of thermal profiles in boreholes extending through the thick unsaturated zone, chloride mass balance, atmospheric radionuclides, and empirical approaches. These methods indicate that near-surface infiltration rates at Yucca Mountain are highly variable in time and space, with local (point) values ranging from zero to several hundred millimeters per year. Spatially distributed net-infiltration values average 5 mm/year, with the highest values approaching 20 mm/year near Yucca Crest. Site-scale recharge estimates range from less than 1 to about 12 mm/year. These results have been incorporated into a site-scale model that has been calibrated using these data sets that reflect infiltration processes acting on highly variable temporal and spatial scales. The modeling study predicts highly non-uniform recharge at the water table, distributed significantly differently from the non-uniform infiltration pattern at the surface.

  9. Estimating recharge at yucca mountain, nevada, usa: comparison of methods

    SciTech Connect

    Flint, A. L.; Flint, L. E.; Kwicklis, E. M.; Fabryka-Martin, J. T.; Bodvarsson, G. S.

    2001-11-01

    Obtaining values of net infiltration, groundwater travel time, and recharge is necessary at the Yucca Mountain site, Nevada, USA, in order to evaluate the expected performance of a potential repository as a containment system for high-level radioactive waste. However, the geologic complexities of this site, its low precipitation and net infiltration, with numerous mechanisms operating simultaneously to move water through the system, provide many challenges for the estimation of the spatial distribution of recharge. A variety of methods appropriate for and environments has been applied, including water-balance techniques, calculations using Darcy's law in the unsaturated zone, a soil-physics method applied to neutron-hole water-content data, inverse modeling of thermal profiles in boreholes extending through the thick unsaturated zone, chloride mass balance, atmospheric radionuclides, and empirical approaches. These methods indicate that near-surface infiltration rates at Yucca Mountain are highly variable in time and space, with local (point) values ranging from zero to several hundred millimeters per year. Spatially distributed net-infiltration values average 5 mm/year, with the highest values approaching 20 nun/year near Yucca Crest. Site-scale recharge estimates range from less than I to about 12 mm/year. These results have been incorporated into a site-scale model that has been calibrated using these data sets that reflect infiltration processes acting on highly variable temporal and spatial scales. The modeling study predicts highly non-uniform recharge at the water table, distributed significantly differently from the non-uniform infiltration pattern at the surface. [References: 57

  10. Estimating recharge at Yucca Mountain, Nevada: A case study

    SciTech Connect

    Flint, A.; Flint, L.; Kwicklis, E.; Fabryka-Martin, J.; Bodvarsson, G.S.

    2001-05-13

    Obtaining values of net infiltration, groundwater travel time, and recharge is necessary at the Yucca Mountain site, Nevada, USA, in order to evaluate the expected performance of a potential repository as a containment system for high-level radioactive waste. However, the geologic complexities of this site, its low precipitation and net infiltration, with numerous mechanisms operating simultaneously to move water through the system, provide many challenges for the estimation of the spatial distribution of recharge. A variety of methods appropriate for arid environments has been applied, including water-balance techniques, calculations using Darcy's law in the unsaturated zone, a soil-physics method applied to neutron-hole water-content data, inverse modeling of thermal profiles in boreholes extending through the thick unsaturated zone, chloride mass balance, atmospheric radionuclides, and empirical approaches. These methods indicate that near-surface infiltration rates at Yucca Mountain are highly variable in time and space, with local (point) values ranging from zero to several hundred millimeters per year. Spatially distributed net-infiltration values average 5 mm/year, with the highest values approaching 20 mm/year near Yucca Crest. Site-scale recharge estimates range from less than 1 to about 12 mm/year. These results have been incorporated into a site-scale model that has been calibrated using these data sets that reflect infiltration processes acting on highly variable temporal and spatial scales. The modeling study predicts highly non-uniform recharge at the water table, distributed significantly differently from the non-uniform infiltration pattern at the surface.

  11. Prelimary methodology for design of stable drifts for the Yucca Mountain Project

    SciTech Connect

    Bauer, S.J.; Ehgartner, B.L.; Hardy, M.P.

    1990-10-01

    This paper discusses the Yucca Mountain Project which is investigating the feasibility of locating a high-level radioactive nuclear waste repository at Yucca Mountain, Nevada. The conceptual design of the repository is described. The design methodology is presented.

  12. Preliminary conceptual model for mineral evolution in Yucca Mountain

    SciTech Connect

    Duffy, C.J.

    1993-12-01

    A model is presented for mineral alteration in Yucca Mountain, Nevada, that suggests that the mineral transformations observed there are primarily controlled by the activity of aqueous silica. The rate of these reactions is related to the rate of evolution of the metastable silica polymorphs opal-CT and cristobalite assuming that a{sub SiO{sub 2(aq)}} is fixed at the equilibrium solubility of the most soluble silica polymorph present. The rate equations accurately predict the present depths of disappearance of opal-CT and cristobalite. The rate equations have also been used to predict the extent of future mineral alteration that may result from emplacement of a high-level nuclear waste repository in Yucca Mountain. Relatively small changes in mineralogy are predicted, but these predictions are based on the assumption that emplacement of a repository would not increase the pH of water in Yucca Mountain nor increase its carbonate content. Such changes may significantly increase mineral alteration. Some of the reactions currently occurring in Yucca Mountain consume H{sup +} and CO{sub 3}{sup 2{minus}}. Combining reaction rate models for these reactions with water chemistry data may make it possible to estimate water flux through the basal vitrophyre of the Topopah Spring Member and to help confirm the direction and rate of flow of groundwater in Yucca Mountain.

  13. Geophysical borehole logging in the unsaturated zone, Yucca Mountain, Nevada

    USGS Publications Warehouse

    Schimschal, Ulrich; Nelson, Philip H.

    1991-01-01

    Borehole geophysical logging for site characterization in the volcanic rocks at the proposed nuclear waste repository at Yucca Mountain, Nevada, requires data collection under rather unusual conditions. Logging tools must operate in rugose, dry holes above the water table in the unsaturated zone. Not all logging tools will operate in this environment, therefore; careful consideration must be given to selection and calibration. A sample suite of logs is presented that demonstrates correlation of geological formations from borehole to borehole, the definition of zones of altered mineralogy, and the quantitative estimates of rock properties. We show the results of an exploratory calculation of porosity and water saturation based upon density and epithermal neutron logs. Comparison of the results with a few core samples is encouraging, particularly because the logs can provide continuous data in boreholes where core samples are not available.

  14. Analysis of thermohydrologic behavior for above-boiling and below-boiling thermal-operating modes for a repository at Yucca Mountain.

    PubMed

    Buscheck, T A; Rosenberg, N D; Blink, J A; Sun, Y; Gansemer, J

    2003-01-01

    We report results from a multi-scale thermohydrologic modeling study for two alternative thermal-operating modes for the potential repository system recently analyzed by the Yucca Mountain Project. These include a Higher-Temperature Operating Mode (HTOM), which results in a localized boiling zone around each emplacement drift, and a Lower-Temperature Operating Mode (LTOM), which always maintains sub-boiling temperatures throughout the repository. The HTOM places all waste packages nearly end to end, making the lineal power density greater than in the LTOM. The lower lineal power density in the LTOM was achieved by placing some waste packages farther apart (which results in a larger repository footprint), and through an increased reliance on pre-closure ventilation to remove the waste-package-generated heat. We focus on temperature T and relative humidity RH at the waste-package and drift-wall surfaces, and on in-drift evaporation. In general, HTOM temperatures are greater than corresponding LTOM temperatures, exhibit similar spatial variability and have a stronger dependence on infiltration flux. The duration of RH reduction on waste packages is similar for the LTOM and HTOM. A major difference between the LTOM and HTOM is the lower waste-package temperature at any given value of waste-package RH for the LTOM. Waste-package temperatures in the LTOM, by design, remain below approximately 85 degrees C; the absence of RH reduction arising from host-rock dryout causes waste-package RH to remain above about 40%. The HTOM waste packages experience higher temperatures and correspondingly lower RH conditions as a result of RH reduction arising from host-rock dryout. For most of the repository area, the HTOM delays the potential onset of gravity-driven seepage compared to the LTOM (as indicated by the duration of boiling at the drift wall). Boiling conditions in the HTOM also delays the onset of capillary-driven seepage into the granular invert, causing the HTOM to have

  15. Potentiometric-surface map, 1993, Yucca Mountain and vicinity, Nevada

    SciTech Connect

    Tucci, P.; Burkhardt, D.J.

    1995-12-31

    The revised potentiometric surface map here, using mainly 1993 average water levels, updates earlier maps of this area. Water levels are contoured with 20-m intervals, with additional 0.5-m contours in the small-gradient area SE of Yucca Mountain. Water levels range from 728 m above sea level SE of Yucca to 1,034 m above sea level north of Yucca. Potentiometric levels in the deeper parts of the volcanic rock aquifer range from 730 to 785 m above sea level. The potentiometric surface can be divided into 3 regions: A small gradient area E and SE of Yucca, a moderate-gradient area on the west side of Yucca, and a large-gradient area to the N-NE of Yucca. Water levels from wells at Yucca were examined for yearly trends (1986-93) using linear least-squares regression. Of the 22 wells, three had significant positive trends. The trend in well UE-25 WT-3 may be influenced by monitoring equipment problems. Tends in USW WT-7 and USW WTS-10 are similar; both are located near a fault west of Yucca; however another well near that fault exhibited no significant trend.

  16. Yucca Mountain Area Saturated Zone Dissolved Organic Carbon Isotopic Data

    SciTech Connect

    Thomas, James; Decker, David; Patterson, Gary; Peterman, Zell; Mihevc, Todd; Larsen, Jessica; Hershey, Ronald

    2007-06-25

    Groundwater samples in the Yucca Mountain area were collected for chemical and isotopic analyses and measurements of water temperature, pH, specific conductivity, and alkalinity were obtained at the well or spring at the time of sampling. For this project, groundwater samples were analyzed for major-ion chemistry, deuterium, oxygen-18, and carbon isotopes of dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC). The U.S. Geological Survey (USGS) performed all the fieldwork on this project including measurement of water chemistry field parameters and sample collection. The major ions dissolved in the groundwater, deuterium, oxygen-18, and carbon isotopes of dissolved inorganic carbon (DIC) were analyzed by the USGS. All preparation and processing of samples for DOC carbon isotopic analyses and geochemical modeling were performed by the Desert Research Institute (DRI). Analysis of the DOC carbon dioxide gas produced at DRI to obtain carbon-13 and carbon-14 values was conducted at the University of Arizona Accelerator Facility (a NSHE Yucca Mountain project QA qualified contract facility). The major-ion chemistry, deuterium, oxygen-18, and carbon isotopes of DIC were used in geochemical modeling (NETPATH) to determine groundwater sources, flow paths, mixing, and ages. The carbon isotopes of DOC were used to calculate groundwater ages that are independent of DIC model corrected carbon-14 ages. The DIC model corrected carbon-14 calculated ages were used to evaluate groundwater travel times for mixtures of water including water beneath Yucca Mountain. When possible, groundwater travel times were calculated for groundwater flow from beneath Yucca Mountain to down gradient sample sites. DOC carbon-14 groundwater ages were also calculated for groundwaters in the Yucca Mountain area. When possible, groundwater travel times were estimated for groundwater flow from beneath Yucca Mountain to down gradient groundwater sample sites using the DOC calculated

  17. Tunnel boring machine applications; Yucca Mountain Exploratory Studies Facility

    SciTech Connect

    Bhattacharyya, K.K.; McDonald, R.; Saunders, R.S.

    1992-11-01

    This paper reports that characterization of Yucca Mountain for a potential repository requires construction of an underground Exploratory Studies Facility (ESF). Mechanical excavating methods have been proposed for construction of the ESF as they offer a number of advantages over drilling and blasting at the Yucca Mountain site, including; less ground disturbance and therefore a potential for less adverse effects on the integrity of the site, creation of a more stable excavation cross section requiring less ground support, and an inherently safer and cleaner working environment. The tunnel boring machine (TBM) provides a proven technology for excavating the welded and unwelded Yucca Mountain tuffs. The access ramps and main underground tunnels form the largest part of the ESF underground construction work, and have been designed for excavation by TBM.

  18. Paleoclimatic and paleohydrologic records from secondary calcite: Yucca Mountain, Nevada

    SciTech Connect

    Whelan, J.F.; Stuckless, J.S.; Moscati, R.J.; Vaniman, D.T.

    1994-12-31

    Stable isotope analyses of calcite and opal, fluid inclusion formation conditions and gas compositions, Sr isotope ratios, and REE compositions all support formation of secondary calcite in the unsaturated zone of Yucca Mountain from infiltration of surface-derived (and soil zone buffered) waters of meteoric origin. Detailed sampling of growth-banding preserved by the secondary calcite should provide a record of past variations in the stable isotope chemistry of these infiltrating waters, and, hence, of precipitation at Yucca Mountain, i.e., a proxy of past climate at Yucca Mountain. The precision of this record depends on how well it can be dated. The distribution and texture of secondary calcite occurrences, if mapped in careful detail from existing bore hole samples and underground workings (as exposures become accessible), could provide a time/space map of fracture and fault unsaturated-zone ground water flow-paths during past wetter climates which might prevail in the future with change in climate.

  19. Characterization of a desert soil sequence at Yucca Mountain, NV

    SciTech Connect

    Guertal, W.R.; Hofmann, L.L. Hudson, D.B.; Flint, A.L.

    1994-12-31

    Yucca Mountain, Nevada, is currently being evaluated as a potential site for a geologic repository for high level radioactive waste. Hydrologic evaluation of the unsaturated zone of Yucca Mountain is being conducted as an integrated set of surface and subsurface-based activities with a common objective to characterize the temporal and spatial distribution of water flux through the potential repository. Yucca Mountain is covered with a thin to thick layer of colluvial/alluvial materials, where there are not bedrock outcrops. It is across this surface boundary that all infiltration and all exfiltration occurs. This surface boundary effects water movement through the unsaturated zone. Characterization of the hydrologic properties of surficial materials is then a necessary step for short term characterization goals and for long term modeling.

  20. The vegetation of Yucca Mountain: Description and ecology

    SciTech Connect

    1996-03-29

    Vegetation at Yucca Mountain, Nevada, was monitored over a six-year period, from 1989 through 1994. Yucca Mountain is located at the northern limit of the Mojave Desert and is the only location being studied as a potential repository for high-level nuclear waste. Site characterization consists of a series of multidisciplinary, scientific investigations designed to provide detailed information necessary to assess the suitability of the Yucca Mountain Site as a repository. This vegetation description establishes a baseline for determining the ecological impact of site characterization activities; it porvides input for site characterization research and modeling; and it clarifies vegetation community dynamics and relationships to the physical environment. A companion study will describe the impact of site characterization of vegetation. Cover, density, production, and species composition of vascular plants were monitored at 48 Ecological Study Plots (ESPs) stratified in four vegetation associations. Precipitation, soil moisture, and maximum and minimum temperatures also were measured at each study plot.

  1. The terrestrial ecosystem program for the Yucca Mountain Project

    SciTech Connect

    Ostler, W.K.; O`Farrell, T.P.

    1994-06-01

    DOE has implemented a program to monitor and mitigate impacts associated with site Characterization Activities at Yucca Mountain on the environment. This program has a sound experimental and statistical base. Monitoring data has been collected for parts of the program since 1989. There have been numerous changes in the Terrestrial Ecosystems Program since 1989 that reflect changes in the design and locations of Site Characterization Activities. There have also been changes made in the mitigation techniques implemented to protect important environmental resources based on results from the research efforts at Yucca Mountain. These changes have strengthened DOE efforts to ensure protection of the environmental during Site Characterization. DOE,has developed and implemented an integrated environmental program that protects the biotic environment and will restore environmental quality at Yucca Mountain.

  2. Yucca Mountain Biological Resources Monitoring Program; Annual report, FY91

    SciTech Connect

    1992-01-01

    The US Department of Energy (DOE) is required by the Nuclear Waste Policy Act of 1982 (as amended in 1987) to study and characterize Yucca Mountain as a possible site for a geologic repository for high-level nuclear waste. During site characterization, the DOE will conduct a variety of geotechnical, geochemical, geological, and hydrological studies to determine the suitability of Yucca Mountain as a repository. To ensure that site characterization activities (SCA) do not adversely affect the Yucca Mountain area, an environmental program has been implemented to monitor and mitigate potential impacts and to ensure that activities comply with applicable environmental regulations. This report describes the activities and accomplishments during fiscal year 1991 (FY91) for six program areas within the Terrestrial Ecosystem component of the YMP environmental program. The six program areas are Site Characterization Activities Effects, Desert Tortoises, Habitat Reclamation, Monitoring and Mitigation, Radiological Monitoring, and Biological Support.

  3. Yucca Mountain biological resources monitoring program; Annual report FY92

    SciTech Connect

    1993-02-01

    The US Department of Energy (DOE) is required by the Nuclear Waste Policy Act of 1982 (as amended in 1987) to study and characterize Yucca Mountain as a potential site for a geologic repository for high-level nuclear waste. During site characterization, the DOE will conduct a variety of geotechnical, geochemical, geological, and hydrological studies to determine the suitability of Yucca Mountain as a potential repository. To ensure that site characterization activities (SCA) do not adversely affect the environment at Yucca Mountain, an environmental program has been implemented to monitor and mitigate potential impacts and ensure activities comply with applicable environmental regulations. This report describes the activities and accomplishments of EG&G Energy Measurements, Inc. (EG&G/EM) during fiscal year 1992 (FY92) for six program areas within the Terrestrial Ecosystem component of the YMP environmental program. The six program areas are Site Characterization Effects, Desert Tortoises, Habitat Reclamation, Monitoring and Mitigation, Radiological Monitoring, and Biological Support.

  4. Tectonic stability and expected ground motion at Yucca Mountain

    SciTech Connect

    1984-10-02

    A workshop was convened on August 7-8, 1984 at the direction of DOE to discuss effects of natural and artificial earthquakes and associated ground motion as related to siting of a high-level radioactive waste (HLW) repository at Yucca Mountain, Nevada. A panel of experts in seismology and tectonics was assembled to review available data and analyses and to assess conflicting opinions on geological and seismologic data. The objective of the meeting was to advise the Nevada Nuclear Waste Storage Investigations (NNWSI) Project about how to present a technically balanced and scientifically credible evaluation of Yucca Mountain for the NNWSI Project EA. The group considered two central issues: the magnitude of ground motion at Yucca Mountain due to the largest expected earthquake, and the overall tectonic stability of the site given the current geologic and seismologic data base. 44 refs.

  5. Preliminary LIBS analysis of Yucca Mountain manganese oxide minerals

    SciTech Connect

    Blacic, J.; Pettit, D.; Cremers, D.

    1996-01-01

    The licensing and performance of a potential repository at Yucca Mountain will require the characterization of radionuclide sorptive capacity of the host rock, which in turn calls for hundreds of analyses based on extensive sampling or in situ measurements. A rapid method specifically for characterizing the manganese oxide minerals occurring heterogeneously throughout the Yucca Mountain block as fracture surface coatings is needed. Our unique solution is a laser-induced breakdown spectroscopy (LIBS) surface-analysis technique that is usable in the field to produce high-resolution atomic emission spectra. In tests with manganese oxide minerals and fracture surface coatings from a few Yucca Mountain core samples, we used four spectral bands to show that qualitative measurement of all constituent elements except K and Na (in the presence of Mn) is possible with LIBS. Detailed calibration of final hardware will make the system quantitative.

  6. HYDROLOGIC CHARACTERISTICS OF FAULTS AT YUCCA MOUNTAIN, NEVADA

    SciTech Connect

    R.P. Dickerson

    2000-10-19

    Yucca Mountain comprises a series of north-trending ridges composed of tuffs within the southwest Nevada volcanic field, 120 km northwest of Las Vegas, Nevada. These ridges are formed of east-dipping blocks of interbedded welded and nonwelded tuff that are offset along steep, mostly west-dipping faults that have tens to hundreds of meters of vertical separation. Yucca Mountain is currently under study as a potential site for underground storage of high-level radioactive waste, with the principle goal being the safe isolation of the waste from the accessible environment. To this end, an understanding of the behavior of ground-water flow through the mountain in the unsaturated zone and beneath the mountain in the saturated zone is critical. The percolation of water through the mountain and into the ground-water flow system beneath the potential repository site is predicated on: (1) the amount of water available at the surface as a result of the climatic conditions, (2) the hydrogeologic characteristics of the volcanic strata that compose the mountain. and (3) the hydrogeologic characteristics of the structures, particularly fault zones and fracture networks, that disrupt these strata. This paper addresses the hydrogeologic characteristics of the fault zones at Yucca Mountain, focusing primarily on the central part of the mountain where the potential repository block is located.

  7. Basaltic volcanic episodes of the Yucca Mountain region

    SciTech Connect

    Crowe, B.M.

    1990-03-01

    The purpose of this paper is to summarize briefly the distribution and geologic characteristics of basaltic volcanism in the Yucca Mountain region during the last 10--12 Ma. This interval largely postdates the major period of silicic volcanism and coincides with and postdates the timing of major extensional faulting in the region. Field and geochronologic data for the basaltic rocks define two distinct episodes. The patterns in the volume and spatial distribution of these basaltic volcanic episodes in the central and southern part of the SNVF are used as a basis for forecasting potential future volcanic activity in vicinity of Yucca Mountain. 33 refs., 2 figs.

  8. The Proposed Yucca Mountain Repository From A Corrosion Perspective

    SciTech Connect

    J.H. Payer

    2005-03-10

    Corrosion is a primary determinant of waste package performance at the proposed Yucca Mountain Repository and will control the delay time for radionuclide transport from the waste package. Corrosion is the most probable and most likely degradation process that will determine when packages will be penetrated and the shape size and distribution of those penetrations. The general issues in corrosion science, materials science and electrochemistry are well defined, and the knowledge base is substantial for understanding corrosion processes. In this paper, the Yucca Mountain Repository is viewed from a corrosion perspective.

  9. Estimating the consequences of significant fracture flow at Yucca Mountain

    SciTech Connect

    Gauthier, J.H.; Wilson, M.L.; Lauffer, F.C.

    1991-12-11

    A simple model is proposed for investigating the possibility of significant fracture flow at Yucca Mountain, Nevada. The model allows an estimate of the number of flowing fractures at Yucca Mountain based on the size of the fractures and the yearly volume of infiltrating water. Given the number of flowing fractures, the number of waste containers they contact is estimated by a geometric argument. Preliminary results indicate that the larger the flowing fractures, the lower the releases of radionuclides. Also, even with significant fracture flow, releases could be well below the limits set by the Environmental Protection Agency.

  10. Scenarios constructed for basaltic igneous activity at Yucca Mountain and vicinity; Yucca Mountain Site Characterization Project

    SciTech Connect

    Barr, G.E.; Dunn, E.; Dockery, H.; Barnard, R.; Valentine, G.; Crowe, B.

    1993-08-01

    Basaltic volcanism has been identified as a possible future event initiating a release of radionuclides from a potential repository at the proposed Yucca Mountain high-level waste repository site. The performance assessment method set forth in the Site Characterization Plan (DOE, 1988) requires that a set of scenarios encompassing all significant radionuclide release paths to the accessible environment be described. This report attempts to catalogue the details of the interactions between the features and processes produced by basaltic volcanism in the presence of the presumed groundwater flow system and a repository structure, the engineered barrier system (EBS), and waste. This catalogue is developed in the form of scenarios. We define a scenario as a well-posed problem, starting from an initiating event or process and proceeding through a logically connected and physically possible combination or sequence of features, events, and processes (FEPs) to the release of contaminants.

  11. Performance predictions for mechanical excavators in Yucca Mountain tuffs; Yucca Mountain Site Characterization Project

    SciTech Connect

    Ozdemir, L.; Gertsch, L.; Neil, D.; Friant, J.

    1992-09-01

    The performances of several mechanical excavators are predicted for use in the tuffs at Yucca Mountain: Tunnel boring machines, the Mobile Miner, a roadheader, a blind shaft borer, a vertical wheel shaft boring machine, raise drills, and V-Moles. Work summarized is comprised of three parts: Initial prediction using existing rock physical property information; Measurement of additional rock physical properties; and Revision of the initial predictions using the enhanced database. The performance predictions are based on theoretical and empirical relationships between rock properties and the forces-experienced by rock cutters and bits during excavation. Machine backup systems and excavation design aspects, such as curves and grades, are considered in determining excavator utilization factors. Instanteous penetration rate, advance rate, and cutter costs are the fundamental performance indicators.

  12. Constructing the Exploratory Studies Facility at Yucca Mountain

    SciTech Connect

    Kalia, H.N.; Replogle, J.M.

    1996-05-01

    Yucca Mountain Site Characterization Office of the US Department of Energy (DOE) is constructing an underground Exploratory Studies Facility (ESF), approximately 160 km (100 miles) northwest of Las Vegas, Nevada. This facility is being used to obtain geological, hydrological, geomechanical, thermomechanical and geochemical information to characterize, Yucca Mountain as a potential site to isolate High-Level Radioactive Waste from the accessible environment. The ESF, when completed, will consist of two ramps from surface (North and South ramp) to the potential repository horizon formations, a drift connecting the two ramps, test alcoves, and above and below ground operational support facilities. The ramps and connecting drift are being mined by a 7.62 m (25 ft) diameter, fully shielded, Tunnel Boring Machine (TBM). This paper describes the current status of the construction of the ESF and test alcoves. At the time of this writing, the following has been accomplished: North Ramp excavation is complete; four test alcoves have been excavated and are in use for scientific experiments; the excavation has reached the potential repository horizon; the drift connecting the two ramps is being excavated, and the excavation of a test alcove for thermal testing is in progress. The mining operations are ahead of schedule, and to date March 26, 1996, the TBM has excavated over 4623 m(15,160 ft.) without any major breakdowns or accidents. The average advance for a three shift (two mining shifts) production day has been 33.46 m (110 ft.). Maximum advance for a week was 218.3 m (716 ft.). An Alpine Miner (AM 75) roadheader is being used to excavate test alcoves. The major ground support system consists of Supper Swellex rock bolts, steel sets as required, Williams rock bolts and channels, and welded wire fabric. Various sections of the tunnel have been instrumented, and the entire excavation has been geologically mapped. To date, the site conditions have been those predicted.

  13. Geologic map of the Paintbrush Canyon Area, Yucca Mountain, Nevada

    SciTech Connect

    Dickerson, R.P.; Drake, R.M. II

    1998-11-01

    This geologic map is produced to support site characterization studies of Yucca Mountain, Nevada, site of a potential nuclear waste storage facility. The area encompassed by this map lies between Yucca Wash and Fortymile Canyon, northeast of Yucca Mountain. It is on the southern flank of the Timber Mountain caldera complex within the southwest Nevada volcanic field. Miocene tuffs and lavas of the Calico Hills Formation, the Paintbrush Group, and the Timber Mountain Group crop out in the area of this map. The source vents of the tuff cones and lava domes commonly are located beneath the thickest deposits of pyroclastic ejecta and lava flows. The rocks within the mapped area have been deformed by north- and northwest-striking, dominantly west-dipping normal faults and a few east-dipping normal faults. Faults commonly are characterized by well developed fault scarps, thick breccia zones, and hanging-wall grabens. Latest movement as preserved by slickensides on west-dipping fault scarps is oblique down towards the southwest. Two of these faults, the Paintbrush Canyon fault and the Bow Ridge fault, are major block-bounding faults here and to the south at Yucca Mountain. Offset of stratigraphic units across faults indicates that faulting occurred throughout the time these volcanic units were deposited.

  14. Volcanism Studies: Final Report for the Yucca Mountain Project

    SciTech Connect

    Bruce M. Crowe; Frank V. Perry; Greg A. Valentine; Lynn M. Bowker

    1998-12-01

    This report synthesizes the results of volcanism studies conducted by scientists at the Los Alamos National Laboratory and collaborating institutions on behalf of the Department of Energy's Yucca Mountain Project. An assessment of the risk of future volcanic activity is one of many site characterization studies that must be completed to evaluate the Yucca Mountain site for potential long-term storage of high-level radioactive waste. The presence of several basaltic volcanic centers in the Yucca Mountain region of Pliocene and Quaternary age indicates that there is a finite risk of a future volcanic event occurring during the 10,000-year isolation period of a potential repository. Chapter 1 introduces the volcanism issue for the Yucca Mountain site and provides the reader with an overview of the organization, content, and significant conclusions of this report. The risk of future basaltic volcanism is the primary topic of concern including both events that intersect a potential repository and events that occur near or within the waste isolation system of a repository. Future volcanic events cannot be predicted with certainty but instead are estimated using formal methods of probabilistic volcanic hazard assessment (PVHA). Chapter 2 describes the volcanic history of the Yucca Mountain region (YMR) and emphasizes the Pliocene and Quaternary volcanic record, the interval of primary concern for volcanic risk assessment. The distribution, eruptive history, and geochronology of Plio-Quaternary basalt centers are described by individual center emphasizing the younger postcaldera basalt (<5 Ma). The Lathrop Wells volcanic center is described in detail because it is the youngest basalt center in the YMR. The age of the Lathrop Wells center is now confidently determined to be about 75 thousand years old. Chapter 3 describes the tectonic setting of the YMR and presents and assesses the significance of multiple alternative tectonic models. The Crater Flat volcanic zone is

  15. Geologic and geophysical characterization studies of Yucca Mountain, Nevada, a potential high-level radioactive-waste repository

    USGS Publications Warehouse

    Whitney, J.W.; Keefer, W.R.

    2000-01-01

    In recognition of a critical national need for permanent radioactive-waste storage, Yucca Mountain in southwestern Nevada has been investigated by Federal agencies since the 1970's, as a potential geologic disposal site. In 1987, Congress selected Yucca Mountain for an expanded and more detailed site characterization effort. As an integral part of this program, the U.S. Geological Survey began a series of detailed geologic, geophysical, and related investigations designed to characterize the tectonic setting, fault behavior, and seismicity of the Yucca Mountain area. This document presents the results of 13 studies of the tectonic environment of Yucca Mountain, in support of a broad goal to assess the effects of future seismic and fault activity in the area on design, long-term performance, and safe operation of the potential surface and subsurface repository facilities.

  16. Uranium and Neptunium Desorption from Yucca Mountain Alluvium

    SciTech Connect

    C.D. Scism; P.W. Reimus; M. Ding; S.J. Chipera

    2006-03-16

    Uranium and neptunium were used as reactive tracers in long-term laboratory desorption studies using saturated alluvium collected from south of Yucca Mountain, Nevada. The objective of these long-term experiments is to make detailed observations of the desorption behavior of uranium and neptunium to provide Yucca Mountain with technical bases for a more realistic and potentially less conservative approach to predicting the transport of adsorbing radionuclides in the saturated alluvium. This paper describes several long-term desorption experiments using a flow-through experimental method and groundwater and alluvium obtained from boreholes along a potential groundwater flow path from the proposed repository site. In the long term desorption experiments, the percentages of uranium and neptunium sorbed as a function of time after different durations of sorption was determined. In addition, the desorbed activity as a function of time was fit using a multi-site, multi-rate model to demonstrate that different desorption rate constants ranging over several orders of magnitude exist for the desorption of uranium from Yucca Mountain saturated alluvium. This information will be used to support the development of a conceptual model that ultimately results in effective K{sub d} values much larger than those currently in use for predicting radionuclide transport at Yucca Mountain.

  17. 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.

  18. Understanding the Potential for Volcanoes at Yucca Mountain

    SciTech Connect

    NA

    2002-08-01

    By studying the rocks and geologic features of an area, experts can assess whether it is vulnerable to future volcanic eruptions. Scientists have performed extensive studies at and near Yucca Mountain to determine whether future volcanoes could possibly affect the proposed repository for nuclear waste.

  19. Nature and continuity of the Sundance Fault, Yucca Mountain, Nevada

    SciTech Connect

    Potter, Christopher J.; Dickerson, Robert P.; Day, Warren C.

    2000-01-12

    This report describes the detailed geologic mapping (1:2,400 scale) that was performed in the northern part of the potential nuclear waste repository area at Yucca Mountain, Nevada, to determine the nature and extent of the Sundance Fault zone and to evaluate structural relations between the Sundance and other faults.

  20. Geodesy and contemporary strain in the Yucca Mountain region, Nevada

    SciTech Connect

    Keefer, W.R.; Coe, J.A.; Pezzopane, S.K.; Hunter, W.C.

    1997-10-01

    Geodetic surveys provide important information for estimating recent ground movement in support of seismotectonic investigations of the potential nuclear-waste storage site at Yucca Mountain, Nevada. Resurveys of established level lines document up to 22 millimeters of local subsidence related to the 1992 Little Skull Mountain earthquake, which is consistent with seismic data that show normal-slip rupture and with data from a regional trilateration network. Comparison of more recent surveys with a level line first established in 1907 suggests 3 to 13 centimeters of subsidence in the Crater Flat-Yucca Mountain structural depression that coincides with the Bare Mountain fault; small uplifts also were recorded near normal faults at Yucca Mountain. No significant deformation was recorded by a trilateration network over a 10-year period, except for coseismic deformation associated with the Little Skull Mountain earthquake, but meaningful results are limited by the short temporal period of that data set and the small rate of movement. Very long baseline interferometry that is capable of measuring direction and rates of deformation is likewise limited by a short history of observation, but rates of deformation between 8 and 13 millimeters per year across the basin and Range province are indicated by the available data.

  1. Dialogs on the Yucca Mountain controversy. Special report No. 10

    SciTech Connect

    Schluter, C.M.; Szymanski, J.S.

    1993-08-01

    In an attempt to resolve the controversial issue of tectonic and hydrologic stability of the Yucca Mountain region, the National Academy of Sciences established a Panel on Coupled Hydrologic/Tectonic/HydrothermaI Systems. The Panel has recently released it`s findings in a report entitled Ground Water at Yucca Mountain: How High Can It Rise? The representation of data and the scientific validity of this report was the subject of comprehensive evaluations and reviews which has led to correspondence between Dr. Charles Archarnbeau and Dr. Frank Press, the President of the National Academy of Sciences. All such correspondence prior to April 9, 1993 is covered by TRAC Special Report No. 5, {open_quotes}Dialogs on the Yucca Mountain Controversy.{close_quotes} The present report represents a continuation of the dialog between Dr. Archambeau and Dr. Press; specifically the letter from Dr. Press to Dr. Archambeau dated April 9, 1993 and Archambeau`s response to Press, dated August 19, 1993. In addition to the correspondence between Press and Archambeau, a series of recent reports by other investigators, referred to in the correspondence from Archambeau, are included in this report and document new data and inferences of importance for resolution of the question of suitability of the Yucca Mountain site as a high level nuclear waste repository. These reports also demonstrate that other scientists, not previously associated with the government`s program at Yucca Mountain or the National Academy review of an aspect of that program, have arrived at conclusions that are different than those stated by the Academy review and DOE program scientists.

  2. Age constraints on fluid inclusions in calcite at Yucca Mountain

    SciTech Connect

    Neymark, Leonid A.; Amelin, Yuri V.; Paces, James B.; Peterman, Zell E.; Whelan, Joseph F.

    2001-04-29

    The {sup 207}Pb/{sup 235}U ages for 14 subsamples of opal or chalcedony layers younger than calcite formed at elevated temperature range between 1.88 {+-} 0.05 and 9.7 {+-} 1.5 Ma with most values older than 6-8 Ma. These data indicate that fluids with elevated temperatures have not been present in the unsaturated zone at Yucca Mountain since about 1.9 Ma and most likely since 6-8 Ma. Discordant U-Pb isotope data for chalcedony subsamples representing the massive silica stage in the formation of the coatings are interpreted using a model of the diffusive loss of U decay products. The model gives an age estimate for the time of chalcedony formation around 10-11 Ma, which overlaps ages of clay minerals formed in tuffs below the water table at Yucca Mountain during the Timber Mountain thermal event.

  3. REMOTE MATERIAL HANDLING IN THE YUCCA MOUNTAIN WASTE PACKAGE CLOSURE CELL AND SUPPORT AREA GLOVEBOX

    SciTech Connect

    K.M. Croft; S.M. Allen; M.W. Borland

    2005-08-02

    The Yucca Mountain Waste Package Closure System (WPCS) cells provide for shielding of highly radioactive materials contained in unsealed waste packages. The purpose of the cells is to provide safe environments for package handling and sealing operations. Once sealed, the packages are placed in the Yucca Mountain Repository. Closure of a typical waste package involves a number of remote operations. Those involved typically include the placement of matched lids onto the waste package. The lids are then individually sealed to the waste package by welding. Currently, the waste package includes three lids. One lid is placed before movement of the waste package to the closure cell; the final two are placed inside the closure cell, where they are welded to the waste package. These and other important operations require considerable remote material handling within the cell environment. This paper discusses the remote material handling equipment, designs, functions, operations, and maintenance, relative to waste package closure.

  4. Task 5 -- Tectonic and neotectonic framework of the Yucca Mountain region

    SciTech Connect

    Schweickert, R.A.

    1994-12-31

    Progress on the tectonics of the Yucca Mountain region is described. Results are reported in the following: regional overview of structure and geometry of Meozoic thrust faults and folds in the area around Yucca Mountain; Evaluation of pre-middle Miocecne structure of Grapevine Mountains and it`s relation to Bare Mountain; Kinematic analysis of low and high angle normal faults in the Bare Mountain area, and comparison of structures with the Grapevine Mountains; and Evaluation of paleomagnetic character of tertiary and pre-tertiary units in the Yucca Mountain region.

  5. Development of the Performance Confirmation Program at Yucca Mountain, Nevada

    SciTech Connect

    G.D. LeCain; R. Snell; D. Barr; S.W. Goodin; D. Weaver; F.D. Hansen

    2006-03-17

    The Yucca Mountain Performance Confirmation program consists of tests, monitoring activities, experiments, and analyses to evaluate the adequacy of assumptions, data, and analyses that form the basis of the conceptual and numerical models of flow and transport associated with a proposed radioactive waste repository at Yucca Mountain, Nevada. The Performance Confirmation program uses an eight-stage risk-informed, performance-based approach. Selection of the Performance Confirmation activities (a parameter and a test method) for inclusion in the Performance Confirmation program was done using a risk-informed performance-based decision analysis. The result of this analysis and review was a Performance Confirmation base portfolio that consists of 20 activities. The 20 Performance Confirmation activities include geologic, hydrologic, and construction/engineering testing. Several of the activities were initiated during site characterization and are ongoing. Others activities will commence during construction and/or post emplacement and will continue until repository closure.

  6. Development of the performance confirmation program at YUCCA mountain, nevada

    USGS Publications Warehouse

    LeCain, G.D.; Barr, D.; Weaver, D.; Snell, R.; Goodin, S.W.; Hansen, F.D.

    2006-01-01

    The Yucca Mountain Performance Confirmation program consists of tests, monitoring activities, experiments, and analyses to evaluate the adequacy of assumptions, data, and analyses that form the basis of the conceptual and numerical models of flow and transport associated with a proposed radioactive waste repository at Yucca Mountain, Nevada. The Performance Confirmation program uses an eight-stage risk-informed, performance-based approach. Selection of the Performance Confirmation activities for inclusion in the Performance Confirmation program was done using a risk-informed performance-based decision analysis. The result of this analysis was a Performance Confirmation base portfolio that consists of 20 activities. The 20 Performance Confirmation activities include geologic, hydrologie, and construction/engineering testing. Some of the activities began during site characterization, and others will begin during construction, or post emplacement, and continue until repository closure.

  7. THE PROPOSED YUCCA MOUNTAIN REPOSITORY FROM A CORROSION PERSPECTIVE

    SciTech Connect

    J.H. Payer

    2005-07-29

    In this paper, the proposed Yucca Mountain Repository is viewed from a corrosion perspective. A major component of the long-term strategy for safe disposal of nuclear waste at the Yucca Mountain Repository is first to completely isolate the radionuclides in the waste packages for long times and to greatly retard the egress and transport of radionuclides from penetrated packages. Therefore, long-lived waste packages are important. The corrosion resistance of the waste package outer canister is reviewed, and a framework for the analysis of localized corrosion processes is presented. An overview is presented of the Materials Performance targeted thrust of the U.S. Department of Energy/Office of Civilian Radioactive Waste Management's Office of Science and Technology and International. The thrust program strives for increased scientific understanding, enhanced process models and advanced technologies for corrosion control.

  8. TBM tunneling on the Yucca Mountain Project: Proceedings

    SciTech Connect

    Williamson, G.E.; Gowring, I.M.

    1995-07-01

    The US Department of Energy`s (DOE) Yucca Mountain Project (YMP) is a scientific endeavor to determine the suitability of Yucca Mountain for the first long term, high level nuclear waste repository in the United States. Status of this long-term project form the construction perspective is described. A key element is construction of the Exploratory Studies Facility (ESF), which is being excavated with a 7. 6 m(25 ft) diameter tunnel boring machine (TBM). Development of the ESF may include the excavation of over 15 km (9.3 mi) of tunnel varying in size from 3 to 7.6 m(10 to 25 ft). Prior to construction, extensive constructibility reviews were an interactive part of the final design. Intent was to establish a constructible design that met the long-term stability requirements for radiological safety of a future repository while maintaining flexibility for the scientific investigations and acceptable tunneling productivity.

  9. Preliminary geochemical/geophysical model of Yucca Mountain

    SciTech Connect

    Greenwade, L.E.; Cederberg, G.A.

    1987-12-31

    A comprehensive geochemical/geophysical model incorporates the current and relevant stratigraphic, petrologic, hydrogeologic, geochemical, and material data associated with a candidate repository at Yucca Mountain, Nevada. A geochemical/geophysical model will provide support and confidence to the Systems Performance calculations, determine whether the data collected as part of the site characterization provide the information needed by the design and performance assessment task, and provide the most accurate and referenced foundation on which to base the radionuclide transport calculations. In this report, the known repository data are compiled and unknown parameter values are estimated based on the available data. It is concluded that more data are needed before the geochemical/geophysical model of Yucca Mountain can be regarded as satisfactory and suitable base for multidimensional predicative flow and transport simulations. Recommendations for future studies concerning site characterization and data acquisition are presented. 36 refs., 1 fig., 2 tabs.

  10. Hydration and dehydration of zeolitic tuff from Yucca Mountain, Nevada

    SciTech Connect

    Kranz, R.L.; Bish, D.L.; Blacic, J.D. )

    1989-10-01

    Naturally occurring zeolites expand and contract when hydrated or dehydrated. In tuffaceous rock composed largely of such zeolites, the entire rock may swell or contract significantly as the rock becomes saturated or dries out. If such rock is constrained, significant stresses may develop as a result of hydration or dehydration. We present experimental results that substantiates this. In a zeolitized, non-welded tuff from Yucca Mountain, NV, rock permeability governs the swelling rate since the major constituent, clinoptilolite, hydrates as fast as it can be exposed to water. At Yucca Mountain, where a nuclear waste repository is proposed, strata of welded, devitrified tuff overlie non-welded, zeolitic tuff. Should the hydration state of the units change significantly over the repository lifetime, additional stresses on the same order of magnitude as now exist may develop. {copyright} American Geophysical Union 1989

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

    SciTech Connect

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

    2000-02-17

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

  12. The Yucca Mountain Project Prototype Testing Program; 1989 Status report

    SciTech Connect

    1989-10-01

    The Yucca Mountain Project is conducting a Prototype Testing Program to ensure that the Exploratory Shaft Facility (ESF) tests can be completed in the time available and to develop instruments, equipment, and procedures so the ESF tests can collect reliable and representative site characterization data. This report summarizes the prototype tests and their status and location and emphasizes prototype ESF and surface tests, which are required in the early stages of the ESF site characterization tests. 14 figs.

  13. Determination of HEat Capacity of Yucca Mountain Strtigraphic Layers

    SciTech Connect

    T. Hadgu; C. Lum; J.E. Bean

    2006-06-20

    The heat generated from the radioactive waste to be placed in the proposed geologic repository at Yucca Mountain, Nevada, will affect the thermal-hydrology of the Yucca Mountain stratigraphic layers. In order to assess the effect of the movement of repository heat into the fractured rocks accurate determination of thermodynamic and hydraulic properties is important. Heat capacity is one of the properties that are required to evaluate energy storage in the fractured rock. Rock-grain heat capacity, the subject of this study, is the heat capacity of the solid part of the rock. Yucca Mountain consists of alternating lithostratigraphic units of welded and non-welded ash-flow tuff, mainly rhyolitic in composition and displaying varying degrees of vitrification and alteration. A number of methods exist that can be used to evaluate heat capacity of the stratigraphic layers that consist of different compositions. In this study, the mineral summation method has been used to quantify the heat capacity of the stratigraphic layers based on Kopp's rule. The mineral summation method is an addition of the weighted heat capacity of each mineral found in a specific layer. For this study the weighting was done based on the mass percentage of each mineral in the layer. The method utilized a mineralogic map of the rocks at the Yucca Mountain repository site. The Calico Hills formation and adjacent bedded tuff layers display a bimodal mineral distribution of vitric and zeolitic zones with differing mineralogies. Based on this bimodal distribution in zeolite abundance, the boundary between the vitric and zeolitic zones was selected to be 15% zeolitic abundance. Thus, based on the zeolite abundance, subdivisions have been introduced to these layers into ''vitric'' and ''zeolitic'' zones. Heat capacity values have been calculated for these layers both as ''layer average'' and ''zone average''. The heat capacity determination method presented in this report did not account for spatial

  14. Thermal stability of zeolitic tuff from Yucca Mountain, Nevada

    SciTech Connect

    Bish, D.L.

    1990-04-01

    Thermal models of the proposed repository at Yucca Mountain, Nevada, suggest that rocks near the proposed host rock will experience elevated temperatures for at least 1000 yrs. In order to assess the effects of elevated temperatures on zeolites clinoptilolite and mordenite were investigated using a combination of high-temperature X-ray powder diffraction, thermogravimetric and differential scanning calorimetric analysis, and long-term heating experiments. 13 refs., 7 figs.

  15. Early evaluation of the suitability of the Yucca Mountain site

    SciTech Connect

    Younker, J.L.; Rickertsen, L.D.; Judd, B.R.

    1992-10-01

    This paper evaluates the technical suitability of Yucca Mountain, Nevada, as a potential site for a geologic repository for radioactive waste. The result of this early site-suitability evaluation is that, in the judgment of the Evaluation Team that conducted the evaluation, the evidence supports a conclusion that the site is not unsuitable. Additional information is needed, however, in specific areas before a recommendation on repository development can be made.

  16. Hydrotectonic environment at Yucca Mountain & evidence for recurrent invasions by hydrothermal fluids. Special Report No. 3

    SciTech Connect

    1993-03-01

    This document contains four technical presentations regarding the hydrotectonic environment at Yucca Mountain, Nevada and evidence for recurrent invasions by hydrothermal fluids. These papers by Dr. Gerald Frazier, Dr. Donald Livingston, and Dr. Malcolm Somerville present field evidence for polygenic metasomatic alterations of volcanic rocks at Yucca Mountain. This series of papers is used in conjunction with a set of comments to contradict conclusions in the NAS/NRC Report on Hydrotectonic Conditions at Yucca Mountain.

  17. Alternate conceptual model of ground water flow at Yucca Mountain

    SciTech Connect

    1993-12-31

    Attempts to predict the performance of a high-level nuclear waste repository in the United States have lead to the development of alternative conceptual models of the ground watre flow field in which the repository will be located. This step has come about because of the lage uncertainties involved in predicting the movement of water and radionuclides through an unsaturated fractured rock. Further, one of the standards to which we are comparing performance is probabilistic, so we are forced to try to conceive of all credible scenarios by which ground water may intersect the repository horizon and perhaps transport radionuclides to a given compliance boundary. To simplify this task, the DOE set about identifying alternative conceptual models of ground water flow which are consistent with existing data. Modeling these concepts necessitates the use of simplifying assumptions. Among the modeling assumptions commonly utilized by analysts of the Yucca Mountain site are those of uniformly distributed, small volumes of recharge and matrix or porous media flow. Most scientists would agree that recharge at Yucca Mountain does not occur in this ideal and simplified fashion, yet modeling endeavors continue to commonly utilize this approach. In this paper, we examine the potential effects of focused recharge on the flow field at Yucca Mountain in concert with a fractured matrix and non-equilibrium view of ground water flow.

  18. Yucca Mountain Project Site characterization and exploratory shaft program

    SciTech Connect

    Gertz, C.P.

    1989-01-01

    The Yucca Mountain Project site characterization phase officially began May 28, 1986, when President Reagan recommended Yucca Mountain be studied as a potential site for a high-level nuclear repository. Site characterization activities are defined in the NWPA as those research activities, whether in the field or in the laboratory, that are undertaken to establish the geologic condition and the range of parameters relevant to an evaluation of the suitability of a candidate site. In December 1988, a major program milestone was achieved when the statutory site characterization plan (SCP) was released on schedule to the NRC, State of Nevada, and the public. The SCP describes the studies necessary to determine the suitability of Yucca Mountain for isolating high-level nuclear waste. The site characterization testing program includes activities to establish the geologic conditions and history of the site. New site characterization activities include surface-based tests and exploratory shaft tests. Tests conducted in the exploratory shaft facility (ESF) will study the processes and phenomena contributing to waste isolation performance and the effects of ESF construction and underground conditions at the ESF location. The surface-based tests will extend the results of the ESF test to the entire site area.

  19. Water levels in the Yucca Mountain area, Nevada, 1993

    SciTech Connect

    Tucci, P.; Goemaat, R.L.; Burkhardt, D.J.

    1996-07-01

    Water levels were monitored in 28 wells in the Yucca Mountain area, Nevada, during 1993. Seventeen wells were monitored periodically, generally on a monthly basis, and 11 wells representing 18 intervals were monitored hourly. All wells monitor water levels in Tertiary volcanic rocks, except one that monitors water levels in Paleozoic carbonate rocks. Water levels were measured using calibrated steel tapes and pressure transducers; steel-tape measurements were corrected for mechanical stretch, thermal expansion, and borehole deviation to obtain precise water-level altitudes. Water-level altitudes in the Tertiary volcanic rocks ranged from about 728 meters above sea level east of Yucca Mountain to about 1,034 meters above sea level north of Yucca Mountain. Water-level altitudes in the well monitoring the Paleozoic carbonate rocks varied between 752 and 753 meters above sea level during 1993. Water levels were an average of about 0.04 meter lower than 1992 water levels. All data were acquired in accordance with a quality-assurance program to support the reliability of the data.

  20. Vertical Variability in Saturated Zone Hydrochemistry Near Yucca Mountain, Nevada

    SciTech Connect

    G. Patterson; P. Striffler

    2007-02-17

    The differences in the saturated zone hydrochemistry with depth at borehole NC-EWDP-22PC reflect the addition of recharge along Fortymile Wash. The differences in water chemistry with depth at borehole NC-EWDP-19PB appear to indicate that other processes are involved. Water from the lower part of NC-EWDP-19PB possesses chemical characteristics that clearly indicate that it has undergone cation exchange that resulted in the removal of calcium and magnesium and the addition of sodium. This water is very similar to water from the Western Yucca Mountain facies that has previously been thought to flow west of NC-EWDP-19PB. Water from the lower zone in NC-EWDP-19PB also could represent water from the Eastern Yucca Mountain facies that has moved through clay-bearing or zeolitized aquifer material resulting in the altered chemistry. Water chemistry from the upper part of the saturated zone at NC-EWDP-19PB, both zones at NC-EWDP-22PC, and wells in the Fortymile Wash facies appears to be the result of recharge through the alluvium south of Yucca Mountain and within the Fortymile Wash channel.

  1. The Proposed Yucca Mountain Repository From A Corrosion Perspective

    SciTech Connect

    J.H. Payer

    2005-04-12

    Corrosion is a primary determinant of waste package performance at the proposed Yucca Mountain Repository and will control the delay time for radionuclide transport from the waste package. Corrosion is the most probable and most likely degradation process that will determine when packages will be penetrated and the shape, size, and distribution of those penetrations. The general issues in corrosion science, materials science and electrochemistry are well defined, and the knowledge base is substantial for understanding corrosion processes. In this paper, the Yucca Mountain Repository is viewed from a corrosion perspective. A major component of the long-term strategy for safe disposal of nuclear waste at the Yucca Mountain Repository is first to completely isolate the radionuclides in the waste packages for long times and to greatly retard the egress and transport of radionuclides from penetrated packages. Therefore, long-lived waste packages are important. The corrosion resistance of the waste package outer canister is reviewed, and a framework for the analysis of localized corrosion processes is presented. An overview is presented of the Materials Performance targeted thrust of the U.S. Department of Energy/Office of Civilian Radioactive Waste Management's Office of Science and Technology and International. The thrust program strives for increased scientific understanding, enhanced process models and advanced technologies for corrosion control.

  2. Vertical variability in saturated zone hydrochemistry near Yucca Mountain, Nevada

    USGS Publications Warehouse

    Patterson, G.L.; Striffler, P.S.

    2006-01-01

    The differences in the saturated zone hydrochemistry with depth at borehole NC-EWDP-22PC reflect the addition of recharge along Fortymile Wash. The differences in water chemistry with depth at borehole NC-EWDP-19PB appear to indicate that other processes are involved. Water from the lower part of NC-EWDP-19PB possesses chemical characteristics that clearly indicate that it has undergone cation exchange that resulted in the removal of calcium and magnesium and the addition of sodium. This water is very similar to water from the Western Yucca Mountain facies that has previously been thought to flow west of NC-EWDP-19PB. Water from the lower zone in NC-EWDP-19PB also could represent water from the Eastern Yucca Mountain fades that has moved through day-bearing or zeolitized aquifer material resulting in the altered chemistry. Water chemistry from the upper part of the saturated zone at NC-EWDP-19PB, both zones at NC-EWDP-22PC, and wells in the Fortymile Wash facies appears to be the result of recharge through the alluvium south of Yucca Mountain and within the Fortymile Wash channel.

  3. Selenite transport in unsaturated tuff from Yucca Mountain

    SciTech Connect

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

    1994-04-01

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

  4. Groundwater chemistry at Yucca Mountain, Nevada, and vicinity

    SciTech Connect

    Kerrisk, J.F.

    1987-02-01

    The chemistry of groundwater at Yucca Mountain and vicinity has been reviewed and compared with the chemistry of water from the Nevada Test Site and surrounding areas such as the Amargosa Desert and Oasis Valley. Sodium is the primary cation and carbonate is the primary anion in water from the saturated zone of the tuffaceous aquifer at Yucca Mountain. Other major cations present are calcium, potassium, and magnesium; other major anions are sulfate and chloride, with lesser quantities of fluoride and nitrate. Aqueous silica is also present. The primary purpose of this review was to survey water-composition data and look for relations among the compositional variables that could provide insight into the processes that control the composition and would ultimately affect radionuclide transport. The following conclusions were inferred from the review. Major cation concentrations are controlled by rock dissolution and mineral precipitation reactions as well as by cation exchange with existing minerals. Aqueous carbonate initially comes from atmospheric and soil-zone carbon dioxide, but there is evidence at Yucca Mountain that carbon dioxide in the gas phase of the unsaturated zone supplies additional carbonate to saturated-zone water in the tuffaceous aquifer as mineral dissolution and precipitation reactions raise the pH of the water. This combination is effectively mineral dissolution and precipitation in a system that is open with respect to carbon dioxide. A carbon model for this process is discussed.

  5. Modeling a ponded infiltration experiment at Yucca Mountain, NV

    SciTech Connect

    Hudson, D.B.; Guertal, W.R.; Flint, A.L.

    1994-12-31

    Yucca Mountain, Nevada is being evaluated as a potential site for a geologic repository for high level radioactive waste. As part of the site characterization activities at Yucca Mountain, a field-scale ponded infiltration experiment was done to help characterize the hydraulic and infiltration properties of a layered dessert alluvium deposit. Calcium carbonate accumulation and cementation, heterogeneous layered profiles, high evapotranspiration, low precipitation, and rocky soil make the surface difficult to characterize.The effects of the strong morphological horizonation on the infiltration processes, the suitability of measured hydraulic properties, and the usefulness of ponded infiltration experiments in site characterization work were of interest. One-dimensional and two-dimensional radial flow numerical models were used to help interpret the results of the ponding experiment. The objective of this study was to evaluate the results of a ponded infiltration experiment done around borehole UE25 UZN {number_sign}85 (N85) at Yucca Mountain, NV. The effects of morphological horizons on the infiltration processes, lateral flow, and measured soil hydaulic properties were studied. The evaluation was done by numerically modeling the results of a field ponded infiltration experiment. A comparison the experimental results and the modeled results was used to qualitatively indicate the degree to which infiltration processes and the hydaulic properties are understood. Results of the field characterization, soil characterization, borehole geophysics, and the ponding experiment are presented in a companion paper.

  6. The occurrence and distribution of erionite at Yucca Mountain, Nevada

    SciTech Connect

    Chipera, S.J.; Bish, D.L.

    1989-09-01

    We have conducted an investigation to determine the occurrence and distribution of erionite, a potential carcinogen, at Yucca Mountain, Nevada. Using x-ray powder diffraction techniques yielding detection limits to below 0.05 wt %, we positively identified erionite in only 3 out of 76 bulk and 12 fracture samples investigated. The three erionite-bearing samples (J12-620/630, UE-25aNo.1-1296.2, and USW G4-1314) all occur above the static water level in clay/zeolite-rich horizons near the top of vitrophyres. Erionite occurs as trace amounts of less than 1 wt % in the whole rock, although it may occur locally in significant amounts as fracture fillings (e.g., UE-25aNo.1-1296.2 where it comprises approximately 45 wt % of the fracture filling material). All three occurrences appear to be extremely isolated cases since erionite was not detected in neighboring samples. Erionite at Yucca Mountain apparently formed only in localized microenvironments, possibly restricted to fractures. Since erionite occurs in trace amounts only in extremely isolated instances, it should pose little or no health hazard to workers in the potential repository at Yucca Mountain or to the public. The amounts of erionite liberated to the biosphere should be negligible, particularly when compared with the amounts of erionite occurring naturally at the surface in Nevada and surrounding states. 24 refs., 7 figs., 2 tabs.

  7. TBM performance prediction in Yucca Mountain welded tuff from linear cutter tests

    SciTech Connect

    Gertsch, R.; Ozdemir, L.; Gertsch, L.

    1992-11-01

    This paper discusses performance prediction which were developed for tunnel boring machines operating in welded tuff for the construction of the experimental study facility and the potential nuclear waste repository at Yucca Mountain. The predictions were based on test data obtained from an extensive series of linear cutting tests performed on samples of Topopah String welded tuff from the Yucca Mountain Project site. Using the cutter force, spacing, and penetration data from the experimental program, the thrust, torque, power, and rate of penetration were estimated for a 25 ft diameter tunnel boring machine (TBM) operating in welded tuff. The result show that the Topopah Spring welded tuff (TSw2) can be excavated at relatively high rates of advance with state-of-the-art TBMs. The result also show, however, that the TBM torque and power requirements will be higher than estimated based on rock physical properties and past tunneling experience in rock formations of similar strength.

  8. Movement of shaft and drift construction water in Yucca Mountain, Nevada: An extended study; Yucca Mountain Site Characterization Project

    SciTech Connect

    Sobolik, S.R.; Fewell, M.E.; Eaton, R.R.

    1991-12-01

    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, for which many design options are being considered, including shafts, drifts, and ramps. The information in this report pertains to: (1) engineering calculations of the potential distribution of residual water from constructing the shafts and drifts; (2) numerical calculations predicting the movement of residual construction water from the shaft and drift walls into the rock; and (3) numerical calculations of the movement of residual water and how the movement is affected by ventilation. This document contains information that has been used in preparing Appendix 1 of the Exploratory Studies Facility Design Requirements document for the Yucca Mountain Project.

  9. Potential Future Igneous Activity at Yucca Mountain, Nevada

    SciTech Connect

    M. Cline; F. Perry; G. Valentine; E. Smistad

    2005-05-26

    Location, timing, and volumes of post-Miocene volcanic activity, along with expert judgment, provide the basis for assessing the probability of future volcanism intersecting a proposed repository for nuclear waste at Yucca Mountain, Nevada. Analog studies of eruptive centers in the region that may represent the style and extent of possible future igneous activity at Yucca Mountain have aided in defining the consequence scenarios for intrusion into and eruption through a proposed repository. Modeling of magmatic processes related to magma/proposed repository interactions has been used to assess the potential consequences of a future igneous event through a proposed repository at Yucca Mountain. Results of work to date indicate future igneous activity in the Yucca Mountain region has a very low probability of intersecting the proposed repository. Probability of a future event intersecting a proposed repository at Yucca Mountain is approximately 1.7 x 10{sup -8} per year. Since completion of the Probabilistic Volcanic Hazard Assessment (PVHA) in 1996, anomalies representing potential buried volcanic centers have been identified from aeromagnetic surveys. A re-assessment of the hazard is currently underway to evaluate the probability of intersection in light of new information and to estimate the probability of one or more volcanic conduits located in the proposed repository along a dike that intersects the proposed repository. US Nuclear Regulatory Commission regulations for siting and licensing a proposed repository require that the consequences of a disruptive event (igneous event) with annual probability greater than 1 x 10{sup -8} be evaluated. Two consequence scenarios are considered: (1) igneous intrusion-poundwater transport case and (2) volcanic eruptive case. These scenarios equate to a dike or dike swarm intersecting repository drifts containing waste packages, formation of a conduit leading to a volcanic eruption through the repository that carries the

  10. Final report on feasibility of real-time geochemical analysis at Yucca Mountain, Nevada, using LIBS technology

    SciTech Connect

    Blacic, J.D.; Pettit, D.R.; Cremers, D.A.

    1996-12-01

    Laser-induced breakdown spectroscopy (LIBS) is an analytic method whereby an intense laser pulse is used to vaporize and excite a small volume of material into atomic emission. Calibrated spectral analysis of the laser spark light provides detection and quantification of the elemental composition of the target material. We performed laboratory and field tests to assess the feasibility of developing field-portable LIBS-based instruments for real-time analyses of Yucca Mountain rocks in conjunction with Yucca Mountain Project drilling, coring, sampling, and characterization tasks. We developed one prototype instrument designed to analyze air core drilling dust and another prototype instrument designed to analyze rock and fracture surfaces. In realistic field tests at the Exploratory Studies Facility at Yucca Mountain, Nevada, we demonstrated that the LIBS prototypes are capable of measuring major, minor, and some trace elements in real time. Laboratory LIBS analyses show that we can identify characteristic element ratios in a range of manganese oxide minerals present at Yucca Mountain as fracture surface coatings and matrix grains. Preliminary LIBS analyses also indicate that the U/Na ratio may distinguish tuffs containing the hazardous zeolite mineral erionite from non-erionite bearing tuffs, and that a LIBS-based instrument may be useful to detect in real time the probable presence of erionite encountered in core drilling and other operations at Yucca Mountain.

  11. Construction features of the exploratory shaft at Yucca Mountain

    SciTech Connect

    Adair, G.W.; Fiore, J.N.

    1984-12-31

    The Exploratory Shaft (ES) at Yucca Mountain is planned to be constructed during 1985 and 1986 as part of the detailed site characterization for one of three sites which may be selected as candidates for location of a high-level radioactive waste repository. Conventional mining methods will be used for the shaft sinking phase of the ES project. The ES will be comprised of surface support facilities, a 1480-ft-deep circular shaft lined with concrete to a finished inside diameter of 12 ft, lateral excavations and test installations extending up to 200 ft from the shaft, and long lateral borings extending up to 2300 ft from the shaft. The estimated time for sinking the shaft to a total depth of about 1480 ft and completing the lateral excavations and borings is about two years. The major underground development planned for the primary test level at a depth of 1200 ft consists of the equivalent of 1150 ft of 15- by 15-ft drift. The total volume of rock to be removed from the shaft proper and the lateral excavations totals about 1/2 million cubic feet. Construction equipment for the shaft and underground excavation phases consists of conventional mine hoisting equipment, shot hole and rock bolt drilling jumbos, mucking machines, and hauling machines. The desire to maintain relatively uniform and even walls in selected shaft and drift intervals will require that controlled blasting techniques be employed. Certain lateral boring operations associated with tests to be conducted in the underground development may pose some unusual problems or require specialized equipment. One of the operations is boring and lining a 30-in.-diam by 600-ft-long horizontal hole with a boring machine being developed under the direction of Sandia National Laboratories. Another special operation is coring long lateral holes (500 to 2000 ft) with minimum use of liquid circulating fluids. 8 figures.

  12. Ventilation design for Yucca Mountain Exploratory Studies Facility

    SciTech Connect

    Jurani, R.S.

    1995-12-31

    Yucca Mountain, located in Southern Nevada approximately 160 km northwest of Las Vegas, is currently the site of intensive surface-based and underground investigations. The investigations are required to determine if the site is suitable for long term isolation of the Nation`s high level nuclear waste inventory. A major component of the program is the Exploratory Studies Facility, or ESF. The ESF, when completed, will consist of approximately 25,600 meters of tunnels and drifts. The network of tunnels and drifts will house and support a wide array of testing programs conceived to provide physical information about the site. Information on geologic, geomechanical, and hydrologic data will be used in the repository design if the site is found suitable. Besides a few special requirements, the general ESF ventilation criteria during construction are similar to that of commercial tunneling and mining operations. The minimum air velocity at the Tunnel Boring Machine (TBM) and other active mining faces is 0.51 meter per second (m/s) (100 feet per minute [fpm]). Airways, estimated leakages and ventilation controls are converted into equivalent resistances for input to mine ventilation network computer simulations. VNETPC Version 3.1 computer software is used to generate the ventilation models for optimized system design and component selection. Subsequently, actual performance of the ventilation system will be verified and validated to comply with applicable nuclear regulatory quality assurance requirements. Dust control in the ESF is dependent on effective dust collection, enclosure, and airflow dilution. Minimum use of water, as feasible, is necessary to avoid adding moisture to the potential repository horizon. The limitation of water use for test drilling and TBM operation, and the rigid compliance with applicable federal and state regulations, make the ESF a ventilation design challenge.

  13. Products of an Artificially Induced Hydrothermal System at Yucca Mountain

    SciTech Connect

    S. Levy

    2000-08-07

    Studies of mineral deposition in the recent geologic past at Yucca Mountain, Nevada, address competing hypotheses of hydrothermal alteration and deposition from percolating groundwater. The secondary minerals being studied are calcite-opal deposits in fractures and lithophysal cavities of ash-flow tuffs exposed in the Exploratory Studies Facility (ESF), a 7.7-km tunnel excavated by the Yucca Mountain Site Characterization Project within Yucca Mountain. An underground field test in the ESF provided information about the minerals deposited by a short-lived artificial hydrothermal system and an opportunity for comparison of test products with the natural secondary minerals. The heating phase lasted nine months, followed by a nine-month cooling period. Natural pore fluids were the only source of water during the thermal test. Condensation and reflux of water driven away from the heater produced fluid flow in certain fractures and intersecting boreholes. The mineralogic products of the thermal test are calcite-gypsum aggregates of less than 4-micrometer crystals and amorphous silica as glassy scale less than 0.2 mm thick and as mounds of tubules with diameters less than 0.7 micrometers. The minute crystal sizes of calcite and gypsum from the field test are very different from the predominantly coarser calcite crystals (up to cm scale) in natural secondary-mineral deposits at the site. The complex micrometer-scale textures of the amorphous silica differ from the simple forms of opal spherules and coatings in the natural deposits, even though some natural spherules are as small as 1 micrometer. These differences suggest that the natural minerals, especially if they were of hydrothermal origin, may have developed coarser or simpler forms during subsequent episodes of dissolution and redeposition. The presence of gypsum among the test products and its absence from the natural secondary-mineral assemblage may indicate a higher degree of evaporation during the test than

  14. Pyritic ash-flow tuff, Yucca Mountain, Nevada -- A discussion

    SciTech Connect

    Weiss, S.I.; Larson, L.T.; Noble, D.C.

    1994-12-31

    Textural and mineralogic evidence exists for at least one episode of widespread hydrothermal alteration of volcanic rocks deep in Yucca Mountain, Nevada. Despite this evidence, Castor et al. infer that most of the pyrite found in tuffs at Yucca Mountain was introduced as ejecta (lithic fragments) incorporated during the eruptions of the tuffs, rather than by in-situ hydrothermal activity. Their conclusions appear to be based on their observation that most of the pyrite resides in unaltered to variably altered and veined lithic fragments, whereas pyrite-bearing veins are absent in the tuff matrix, titanomagnetite and mafic phenocrysts in the matrix are generally not replaced by pyrite, and feldspar phenocrysts in the pyritic tuff matrix are generally unaltered. Castor et al. dismiss the much smaller quantities of pyrite disseminated in the tuff matrix, including relatively rare pyritized hornblende and biotite grains, as xenolithic as well. The pyritic tuffs belong to large-volume, subalkaline rhyolite ash-flow units (ca. > 150 to 250 km{sup 3} each). The interpretation of Castor et al. has broad implications for the temperature, fO{sub 2} and fS{sub 2} of major ash flow eruptions. Pyrite origin also bears on the nature of past fluid flow and water-rock reactions at Yucca Mountain, which in turn are important factors in assessing the potential for currently undiscovered mineral resources in the area of the proposed nuclear waste repository. We have studied core and cuttings from the same drill holes studied by Castor et al., as well as other drill holes. It is our contention that the inconsistent lateral and stratigraphic distribution of the pyrite, textural features of the pyrite, and phase stability considerations are incompatible with the {open_quotes}lithic{close_quotes} origin of Castor et al., and are more reasonably explained by in-situ formation from hydrothermal fluids containing low, but geochemically significant, concentrations of reduced sulfur.

  15. Calculations supporting evaluation of potential environmental standards for Yucca Mountain

    SciTech Connect

    Duguid, J.O.; Andrews, R.W.; Brandstetter, E.; Dale, T.F.; Reeves, M.

    1994-04-01

    The Energy Policy Act of 1992, Section 801 (US Congress, 1992) provides for the US Environmental Protection Agency (EPA) to contract the National Academy of Sciences (NAS) to conduct a study and provide findings and recommendations on reasonable standards for the disposal of high-level wastes at the Yucca Mountain site. The NAS study is to provide findings and recommendations which include, among other things, whether a health-based standard based on dose to individual members of the public from releases to the accessible environment will provide a reasonable standard for the protection of the health and safety of the public. The EPA, based upon and consistent with the findings and recommendations of the NAS, is required to promulgate standards for protection of the public from releases from radioactive materials stored or disposed of in a repository at the Yucca Mountain site. This document presents a number of different ``simple`` analyses of undisturbed repository performance that are intended to provide input to those responsible for setting appropriate environmental standards for a potential repository at the Yucca Mountain site in Nevada. Each of the processes included in the analyses has been simplified to capture the primary significance of that process in containing or isolating the waste from the biosphere. In these simplified analyses, the complex waste package interactions were approximated by a simple waste package ``failure`` distribution which is defined by the initiation and rate of waste package ``failures``. Similarly, releases from the waste package and the engineered barrier system are controlled by the very near field environment and the presence and rate of advective and diffusive release processes. Release was approximated by either a simple alteration-controlled release for the high solubility radionuclides and either a diffusive or advective-controlled release for the solubility-limited radionuclides.

  16. Geothermal resource assessment of the Yucca Mountain Area, Nye County, Nevada. Final report

    SciTech Connect

    Flynn, T.; Buchanan, P.; Trexler, D.; Shevenell, L., Garside, L.

    1995-12-01

    An assessment of the geothermal resources within a fifty-mile radius of the Yucca Mountain Project area was conducted to determine the potential for commercial development. The assessment includes collection, evaluation, and quantification of existing geological, geochemical, hydrological, and geophysical data within the Yucca Mountain area as they pertain to geothermal phenomena. Selected geologic, geochemical, and geophysical data were reduced to a set of common-scale digital maps using Geographic Information Systems (GIS) for systematic analysis and evaluation. Available data from the Yucca Mountain area were compared to similar data from developed and undeveloped geothermal areas in other parts of the Great Basin to assess the resource potential for future geothermal development at Yucca Mountain. This information will be used in the Yucca Mountain Site Characterization Project to determine the potential suitability of the site as a permanent underground repository for high-level nuclear waste.

  17. The Application of CFD to Ventilation Calculations at Yucca Mountain

    SciTech Connect

    Danko, G.; Bahrami, D.

    2002-02-27

    This paper presents the results of the application of CFD to ventilation calculations at Yucca Mountain using MULTIFLUX. Seven cases were selected to study the effect of the heat transport coefficient on the drift wall temperature distribution. It was concluded that variable heat transport coefficients such as those given by the differential-parameter CFD used in MULTIFLUX are considered the most appropriate approach of all cases presented. This CFD model agrees well with FLUENT results and produces the lowest temperature results, which is favorable to ventilation performance.

  18. Probable maximum floods at the Yucca Mountain exploration shafts

    SciTech Connect

    Cardle, J.A.; Lim, S.T.

    1990-10-01

    This paper presents an analysis of flood flows in the Coyote Wash at the proposed high level nuclear waste repository site at Yucca Mountain, Nevada. Estimates of the hydrographs at various points in this wash resulting from the 100 year storm and from the probable maximum storms are developed and compared with other results. Flows in this particular wash are particularly critical due to the adjacent location of the proposed exploratory shafts. The resulting hydrographs at the site of the exploratory shaft pad are delineated.

  19. Evidence for ground-water stratification near Yucca Mountain, Nevada

    USGS Publications Warehouse

    Futa, K.; Marshall, B.D.; Peterman, Z.E.

    2006-01-01

    Major- and trace-element concentrations and strontium isotope ratios (strontium-87/strontium-86) in samples of ground water potentially can be useful in delineating flow paths in the complex ground-water system in the vicinity of Yucca Mountain, Nevada. Water samples were collected from boreholes to characterize the lateral and vertical variability in the composition of water in the saturated zone. Discrete sampling of water-producing intervals in the saturated zone includes isolating borehole sections with packers and extracting pore water from core obtained by sonic drilling. Chemical and isotopic stratification was identified in the saturated zone beneath southern Fortymile Wash.

  20. ERMYN: Environmental Radiation Model for the Yucca Mountain, Nevada

    SciTech Connect

    D.W. Wu; M.A. Wasiolek; J.J. Tappen; K.R. Rautenstrauch; A.J. Smith

    2002-11-18

    This paper briefly describes a new biosphere model, ERMYN, that was developed to characterize biosphere processes for radionuclides released from the proposed high-level radioactive waste geologic repository at Yucca Mountain (YM). Biosphere modeling for YM is conducted independently for two radionuclide release modes and resulting exposure scenarios, groundwater release and volcanic release. This paper focuses on the model for groundwater release. The groundwater release exposure scenario addresses the case in which the geosphere-biosphere interface is well extraction of contaminated groundwater.

  1. System safety analysis of the Yucca Mountain tunnel boring machine

    SciTech Connect

    Smith, M.G.; Booth, L.; Eisler, L.

    1995-12-01

    The purpose of this analysis was to systematically identify and evaluate hazards related to the tunnel boring machine to be used at Yucca Mountain. This analysis required three steps to complete the risk evaluation: hazard/scenario identification, consequence assessment, and frequency assessment. The result was a `risk evaluation` of the scenarios identified in this analysis in accordance with MIL-STD-882C. The risk assessment in this analysis characterized the accident scenarios associated with the TBM in terms of relative risk and included recommendations for mitigating all identified risks.

  2. Natural Barriers of the Geosphere at Yucca Mountain, Nevada

    NASA Astrophysics Data System (ADS)

    Arlt, H.; Kotra, J.; Mohanty, S.; Winterle, J.

    2005-05-01

    Geological repositories designed to isolate high-level radioactive waste need natural and engineered barriers that prevent or slow the release of radioactive elements into the accessible environment to acceptable regulatory limits. Under the U.S. Nuclear Regulatory Commission's (NRC's) regulations, a barrier is any material, structure, or feature that prevents or substantially reduces the rate of movement of water or radionuclides from the repository to the accessible environment. In 1982, Congress passed the Nuclear Waste Policy Act which directed the NRC to include multiple barriers in regulating geologic disposal of high-level radioactive waste. Accordingly, as provided in 10 CFR Part 63, the NRC's regulations for Yucca Mountain require a repository to include multiple barriers to ensure the system is robust and not wholly dependent on any single barrier. Any potential license application to construct a repository at Yucca Mountain must identify the multiple barriers (both natural and engineered), describe the capabilities of each barrier, and provide the technical bases for the capabilities of the barriers. The NRC believes that understanding the capability of the repository's component barriers improves understanding of the overall system. The objective of this paper is to discuss potential natural barriers of the geosphere at Yucca Mountain and describe the NRC regulatory requirements for such barriers. To better understand the natural barriers of the geosphere, it helps to divide the barriers into groups of features and their associated processes. Natural barriers, i.e., barriers not constructed by man, ideally include processes that delay the transport of radionuclides from reaching the accessible environment or limit the amount of water that can seep from a ground surface to the depth of an underground repository. Natural barriers at Yucca Mountain may include: topographic influences on precipitation runoff; soil and plants influences on evaporation and

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

    SciTech Connect

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

    1995-05-01

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

  4. The exploratory studies facility (ESF) at Yucca Mountain - Description and status

    SciTech Connect

    Simecka, W.B.; Replogle, J.M.; Mckenzie, D.G.

    1994-12-31

    The Exploratory Studies Facility (ESF) at Yucca Mountain, Nevada will be a 25 kilometer underground network of inclined ramps, tunnels, and test alcoves. It will serve as an underground laboratory for the execution of a testing program conceived to assess the suitability of Yucca Mountain as a site to host a potential high level nuclear waste repository. This paper contains a description of the ESF, a summary of the major types of tests currently planned, and a report on the current status of the ongoing design and construction activities. The ESF is being designed and constructed in phases. Currently, the Detailed Design, or {open_quotes}Title II Design{close_quotes} is centered on the second of ten major design packages. Construction has begun on excavation of the {open_quotes}starter tunnel{close_quotes} for a Tunnel Boring Machine (TBM) expected to begin operation in late FY 1994. The EFS program will provide information critical to the evaluation of Yucca Mountain as a potential repository site, and will house a suite of state-of-the-art tests designed to gather this information. The ESF is a one of a kind opportunity to examine, in minute detail, all facets of a sites` geology; its thermal, mechanical, and hydrologic properties; and to study the linkages between these properties.

  5. Construction of the exploratory studies facility at Yucca Mountain - North Ramp

    SciTech Connect

    Kalia, H.N.; Repogle, J.M.; McNeely, J.E.

    1995-05-01

    Yucca Mountain Site Characterization Office of the US Department of Energy is constructing an Exploratory Studies Facility, approximately 160 km (100 miles) northwest of Las Vegas, Nevada. This facility will be used to gather geological, hydrological, geomechanical, thermomechanical, and geochemical information to characterize Yucca Mountain as a potential site to isolate High-Level Radioactive Waste from the accessible environment. The Exploratory Studies Facility, when completed shall consist of two ramps from the surface, a connecting drift, underground test areas and below ground operational support facilities. The ramps and connecting drift are being mined by a 7.62 m (25 ft) diameter Tunnel Boring Machine. This machine was fabricated for the Department of Energy by Construction Tunneling Services, Inc; of Kent, Washington. This paper describes the current status of the concentration of the North Ramp at Yucca Mountain. At the time of this writing, the North Ramp had advanced to a distance of about 517 m (1700 ft). With the exception of some minor problems through Bow Ridge fault, the excavation has progressed as expected.

  6. GENISES: A GIS Database for the Yucca Mountain Site Characterization Project

    SciTech Connect

    Beckett, J.

    1991-12-31

    This paper provides a general description of the Geographic Nodal Information Study and Evaluation System (GENISES) database design. The GENISES database is the Geographic Information System (GIS) component of the Yucca Mountain Site Characterization Project Technical Database (TDB). The GENISES database has been developed and is maintained by EG & G Energy Measurements, Inc., Las Vegas, NV (EG & G/EM). As part of the Yucca Mountain Project (YMP) Site Characterization Technical Data Management System, GENISES provides a repository for geographically oriented technical data. The primary objective of the GENISES database is to support the Yucca Mountain Site Characterization Project with an effective tool for describing, analyzing, and archiving geo-referenced data. The database design provides the maximum efficiency in input/output, data analysis, data management and information display. This paper provides the systematic approach or plan for the GENISES database design and operation. The paper also discusses the techniques used for data normalization or the decomposition of complex data structures as they apply to GIS database. ARC/INFO and INGRES files are linked or joined by establishing ``relate`` fields through the common attribute names. Thus, through these keys, ARC can allow access to normalized INGRES files greatly reducing redundancy and the size of the database.

  7. Geology of the ECRB Cross Drift-Exploratory Studies Facility, Yucca Mountain Project, Yucca Mountain, Nevada

    SciTech Connect

    DOE,

    1999-01-01

    The Enhanced Characterization of the Repository Block Cross Drift (Cross Drift) excavated at Yucca Mountain is being studied to determine its suitability as a permanent high-level nuclear waste repository. This report presents a summary of data collected by the U.S. Bureau of Reclamation (USBR) personnel on behalf of the U.S. Geological Survey (USGS) for the Department of Energy in the Cross Drift from Sta. 00+00 to 26+64. This report includes descriptions of lithostratigraphic units, an analysis of data from full-periphery geologic maps (FPGM) and detailed line survey (DLS) data, a detailed description of the Solitario Canyon Fault zone (SCFZ), and an analysis of geotechnical and engineering characteristics. The Cross Drift is excavated entirely within the Topopah Spring Tuff formation of the Paintbrush Group. Units exposed in the crystal-poor member of the Topopah Spring Tuff, include the Topopah Spring crystal-poor upper lithophysal zone (Tptpul) (Sta. 0+00 to 10+15), the Topopah Spring crystal-poor middle nonlithophysal zone (Tptpmn) (Sta. 10+15 to 14+44), the Topopah Spring crystal-poor lower lithophysal zone (Tptpll) (Sta. 14+44 to 23+26), and the Topopah Spring crystal-poor lower nonlithophysal zone (Tptpln) (Sta. 23+26 to 25+85). The lower portion of the Topopah Spring crystal-rich lithophysal transition subzone (Tptrl1) is exposed on the west side of the Solitario Canyon fault from Sta. 26+57.5 to 26+64. Lithologically, the units exposed in the Cross Drift are similar in comparable stratigraphic intervals of the Exploratory Studies Facility (ESF), particularly in terms of welding, secondary crystallization, fracturing, and type, size, color, and abundance of pumice and lithic clasts. The most notable difference is the lack of the intensely fractured zone (IFZ) in the Cross Drift. The as-built cross section and the pre-construction cross section compare favorably. Lithostratigraphic contacts and structures on the pre-construction cross section were

  8. Passive Seismic Monitoring for Rockfall at Yucca Mountain: Concept Tests

    SciTech Connect

    Cheng, J; Twilley, K; Murvosh, H; Tu, Y; Luke, B; Yfantis, A; Harris, D B

    2003-03-03

    For the purpose of proof-testing a system intended to remotely monitor rockfall inside a potential radioactive waste repository at Yucca Mountain, a system of seismic sub-arrays will be deployed and tested on the surface of the mountain. The goal is to identify and locate rockfall events remotely using automated data collecting and processing techniques. We install seismometers on the ground surface, generate seismic energy to simulate rockfall in underground space beneath the array, and interpret the surface response to discriminate and locate the event. Data will be analyzed using matched-field processing, a generalized beam forming method for localizing discrete signals. Software is being developed to facilitate the processing. To date, a three-component sub-array has been installed and successfully tested.

  9. DEGRADATION MODES OF ALLOY 22 IN YUCCA MOUNTAIN REPOSITORY CONDITIONS

    SciTech Connect

    F. Hua; G.M. Gordon; R.B. Rebak

    2005-10-13

    The nuclear waste package design for Yucca Mountain (Nevada, USA), in its current configuration, consists of a double wall cylindrical container fabricated using a highly corrosion resistant Ni-based Alloy 22 for the outer barrier and type 316 stainless steel for the inner structural vessel. A mailbox-shaped drip shield fabricated primarily using Ti Grade 7 will cover the waste packages. The environmental degradation of the relevant materials have been extensively studied and modeled for over ten years. This paper reviews the state-of-the-art understanding of the degradation modes of Alloy 22 (N06022) due to its interaction with the predicted in-drift mountain conditions including temperature and types of electrolytes. Subjects discussed include thermal aging and phase stability, dry oxidation, general and localized corrosion, stress corrosion cracking and hydrogen induced cracking.

  10. Degradation Modes of Alloy 22 in Yucca Mountain Repository Conditions

    SciTech Connect

    Hua, F; Gordon, G M; Mon, K G; Rebak, R B

    2005-11-05

    The nuclear waste package design for Yucca Mountain (Nevada, USA), in its current configuration, consists of a double wall cylindrical container fabricated using a highly corrosion resistant Ni-based Alloy 22 for the outer barrier and type 316 stainless steel for the inner structural vessel. A mailbox-shaped drip shield fabricated primarily using Ti Grade 7 will cover the waste packages. The environmental degradation of the relevant materials have been extensively studied and modeled for over ten years. This paper reviews the state-of-the-art understanding of the degradation modes of Alloy 22 (N06022) due to its interaction with the predicted in-drift mountain conditions including temperature and types of electrolytes. Subjects discussed include thermal aging and phase stability, dry oxidation, general and localized corrosion, stress corrosion cracking and hydrogen induced cracking.

  11. Groundwater Oxidizing and Reducing Conditions Near Yucca Mountain

    NASA Astrophysics Data System (ADS)

    Al-Qudah, O. M.; Woocay, A.; Walton, J. C.

    2008-12-01

    Groundwater data from 73 wells in Yucca Mountain region were analyzed to better understand geochemical conditions and to make reducing/oxidizing (Redox) environment comparisons. Major ion chemistry, silica, fluoride and associated saturation indices, determined with PHREEQC, were sequentially examined using the multivariate statistical methods of principal component factor analysis and k means cluster analysis. Analysis of both major ion concentration data and their saturation indices allow simultaneous consideration of arithmetic (raw concentrations) and logarithmic (saturation indices) variables that describe the hydrochemical system and therefore can provide further insight into the system's behavior. The factor analysis of the major ion and saturation indices transforms the variables into a tractable number of descriptive factors that are rotated to summarize the chemical groundwater system and better interpret system variation. Results obtained from these analyses show a good agreement with literatures results. Literature indicates that the saturated zone (SZ) located to the east and south of the Yucca Mountain has reducing conditions, and oxidizing conditions are found elsewhere in the SZ flow system.

  12. Isotopic discontinuities in ground water beneath Yucca Mountain, Nevada

    USGS Publications Warehouse

    Stuckless, J.S.; Whelan, J.F.; Steinkampf, W.C.

    1991-01-01

    Analytical data for stable isotopes in ground water from beneath Yucca Mountain, when examined in map view, show areal patterns of heterogeneity that can be interpreted in terms of mixing of at least three end members. One end member must be isotopically heavy in terms of hydrogen and oxygen and have a young apparent 14C age such as water found at the north end of Yucca Mountain beneath Fortymile Wash. A second end member must contain isotopically heavy carbon and have an old apparent 14C age such as water from the Paleozoic aquifer. The third end member cannot be tightly defined. It must be isotopically lighter than the first with respect of hydrogen and oxygen and be intermediate to the first and second end members with respect to both apparent 14C age and ?? 13C. The variable isotopic compositions of hydrogen and oxygen indicate that two of the end members are waters, but the variable carbon isotopic composition could represent either a third water end member or reaction of water with a carbon-bearing solids such as calcite.

  13. Erosional decay of the Yucca Mountain crest, Nevada

    NASA Astrophysics Data System (ADS)

    Stüwe, K.; Robl, J.; Matthai, S.

    2009-07-01

    A simple numerical landscape evolution model is used to investigate the rate of erosional decay of the Yucca Mountain crest in Nevada, USA — a location proposed as a permanent repository for high level radioactive waste. The model is based on a stream power approach in which we assume that the rate of erosion is proportional to the size of the catchment as a proxy for water flux and to the square of the topographic gradient. The proportionality constants in the model are determined using the structural history of the region: extensional tectonics has dissected the region into a series of well-defined tilt blocks in the last 11 my and the ratio of fault displacement and gully incision during this time is used to scale the model. Forward predictions of our model into the future show that the crest will denude to the level of the proposed site between 500,000 years and 5 my. This prediction is based on conservative estimates for all involved parameters. Erosion may be more rapid if other processes are involved. For example, our model does not consider continuing uplift or catastrophic surface processes as they have been recorded in the region. We conclude that any "total system performance analysis" (TSPA — as has been performed for the Yucca Mountain region to predict geological events inside the ridge) must consider erosion as an integral part of its predictions.

  14. Tunneling on the Yucca Mountain Project: Progress and lessons learned

    SciTech Connect

    Hansmire, W.H.; Rogers, D.J.; Wightman, W.D.

    1996-06-01

    The Yucca Mountain Site Characterization Project is the US`s effort to confirm the technical acceptability of Yucca Mountain as a repository for high-level nuclear waste. A key part of the site characterization project is the construction of a 7.8-km-long, 7.6-m-diameter tunnel for in-depth geologic and other scientific investigations. The work is governed in varying degrees by the special requirements for nuclear quality assurance, which imposes uncommon and often stringent limitations on the materials which can be used in construction, the tunneling methods and procedures used, and record-keeping for many activities. This paper presents the current status of what has been learned, how construction has adapted to meet the requirements, and how the requirements were interpreted in a mitigating way to meet the legal obligations, yet build the tunnel as rapidly as possible. With regard to design methodologies and the realities of tunnel construction, ground support with a shielded Tunnel Boring Machine is discussed. Notable lessons learned include the need for broad design analyses for a wide variety of conditions and how construction procedures affect ground support.

  15. Sorption Charecterization of Radonuclides on Clays in Yucca Mountain Alluvium

    SciTech Connect

    M. Ding; P.W. Reimus; S. Chipera; C. Scism

    2006-03-17

    Sorption of {sup 237}Np(V) and {sup 233}U(VI) was measured on clays separated from Yucca Mountain alluvium as a function of solution pH and aqueous actinide concentrations. The results indicate that sorption of U and Np on the separated clay fraction depends strongly on solution pH. Np sorption on clays increases slowly with increasing pH from 3 to 7. Above pH 7, Np sorption on clays increases rapidly up to a pH of about 10. On the other hand, U sorption on clays reaches it maximum at a pH of about 6, with sorption decreasing as pH increases from 6 to 8 and then increasing again as pH increases further from 8 to about 10. The results suggest that a Freundlich isotherm can be used to describe U and Np sorption on clays at pH above 5.5. The results of this study indicate that clay minerals play a very important role in the sorption of U and Np on Yucca Mountain alluvium. Indeed, the clay content of the alluvium is probably considerably more important than water chemistry in predicting the ability of the alluvium to attenuate the transport of these radionuclides.

  16. Isotopic studies of Yucca Mountain soil fluids and carbonate pedogenesis

    SciTech Connect

    McConnaughey, T.A.; Whelan, J.F.; Wickland, K.P.; Moscati, R.J.

    1994-12-31

    Secondary carbonates occurring within the soils, faults, and subsurface fractures of Yucca Mountain contain some of the best available records of paleoclimate and palehydrology for the potential radioactive waste repository site. This article discusses conceptual and analytical advances being made with regard to the interpretation of stable isotope data from pedogenic carbonates, specifically related to the {sup 13}C content of soil CO{sub 2}, CaCO{sub 3}, precipitation mechanisms, and isotopic fractionations between parent fluids and precipitating carbonates. The {sup 13}C content of soil carbon dioxide from Yucca Mountain and vicinity shows most of the usual patterns expected in such contexts: Decreasing {sup 13}C content with depth decreasing {sup 13}C with altitude and reduced {sup 13}C during spring. These patterns exist within the domain of a noisy data set; soil and vegetational heterogeneities, weather, and other factors apparently contribute to isotopic variability in the system. Several soil calcification mechanisms appear to be important, involving characteristic physical and chemical environments and isotopic fractionations. When CO{sub 2} loss from thin soil solutions is an important driving factor, carbonates may contain excess heavy isotopes, compared to equilibrium precipitation with soil fluids. When root calcification serves as a proton generator for plant absorption of soil nutrients, heavy isotope deficiencies are likely. Successive cycles of dissolution and reprecipitation mix and redistribute pedogenic carbonates, and tend to isotopically homogenize and equilibrate pedogenic carbonates with soil fluids.

  17. Technical data management at the Yucca Mountain Site Characterization Project

    SciTech Connect

    Statler, J.; Newbury, C.M.; Heitland, G.W.

    1992-09-01

    The Department of Energy/Office of Civilian Radioactive waste Management (DOE/OCRWM) is responsible for the characterization of Yucca Mountain, Nevada, to determine its potential as a site of a high-level radioactive waste repository. The characterization of Yucca Mountain encompasses many diverse investigations, both onsite and in laboratories across the country. Investigations are being conducted of the geology, hydrology, mineralogy, paleoclimate, geotechnical properties, and archeology of the area, to name a few. Effective program management requires that data from site investigations be processed, interpreted and disseminated in a timely manner to support model development and validation, repository design, and performance assessment. The Program must also meet regulatory requirements for making the technical data accessible to a variety of external users throughout the life of the Project. Finally, the DOE/OCRWM must make available the data or its description and access location available for use in support of the license application and supporting documentation. To accomplish these objectives, scientific and engineering data, generated by site characterization activities, and technical data, generated by environmental and socioeconomic impact assessment activities, must be systematically identified, cataloged, stored and disseminated in a controlled manner.

  18. Inquiring minds want to know about Yucca Mountain

    SciTech Connect

    Volek, S.M.; Reilly, B.E.

    1989-12-31

    This paper presents a review of the Yucca Mountain Project`s public affairs activities during the past year. The selection of Yucca Mountain as the first site to be characterized as a potential high-level nuclear waste repository has generated additional public interest in an already controversial program. To meet this increased level of concern by Nevada residents and media, the project office has stepped up its public affairs program. In addition to presentations in response to invitations by business, civic and service groups, an information office, exhibit showings and other standard public information activities, this effort includes a new direction in planning major project update meetings. This approach focuses on what the public wants to know, rather than on how scientists and engineers describe their work. Agendas are structured around informal discussions with Nevada residents in different parts of the state. The State of Nevada is invited to share the podium. Controversial issues are addressed head-on, and maximum time is allotted for audience participation.

  19. THE DRIFT SCALE HEATER TEST AT YUCCA MOUNTAIN, NEVADA

    SciTech Connect

    Peters, Mark T.; Boyle, William J.; Datta, Robin N.; Elkins, Ned Z.; Yasek, Robert N.; Wagner, Ralph A.; Weaver, Douglas J.

    1998-01-30

    The Drift Scale Heater Test (DST) is an integral part of the program of testing and studies being conducted by the U.S. Department of Energy to evaluate the suitability of Yucca Mountain, Nevada as a site of a deep geologic repository for the permanent disposal of spent nuclear fuel and high-level nuclear waste. The DST is a large-scale, in situ thermal test to be conducted over nearly a decade in the Exploratory Studies Facility at Yucca Mountain (Figure 1). The overall objective of the DST is to acquire a more indepth understanding of the physical processes that will occur in the rock surrounding the emplaced waste. There are four principal processes of concern: thermal, mechanical, hydrological, and chemical. These processes will be intensified because of the decay heat from the emplaced waste and their interaction or coupling. An understanding of these coupled processes is essential for the assessment of the long-term (over thousands of years) performance of the repository.

  20. Aeromagnetic map of Yucca Mountain and surrounding regions, southwest Nevada

    USGS Publications Warehouse

    Kane, Martin Francis; Bracken, Robert E.

    1983-01-01

    Magnetic anomalies over Yucca Mountain and surrounding areas are largely caused by variations in magnetic properties and shapes, including structural offsets, of the extensive volcanic units that underlie the region. In a few places the anomalies are caused by intrusions. Correlation between magnetic properties measured from rock samples and those derived from rock unit-magnetic anomaly associations is excellent. Anomaly characteristics, extensive magnetic gradients, and marked changes in the regional magnetic field can be coupled with the magnetic properties of the rock units to delineate structural boundaries. Three major boundaries are indicated by contrasts in regional magnetic expressions. Less extensive but more clearly indicated boundaries in the immediate vicinity of Yucca Mountain are interpreted from a distinctive pairing of northerly-trending linear positive and negative anomalies which are caused by vertical displacement in generally gently dipping volcanic beds. The displacement between beds is located approximately along the border line between the linear anomaly pairs. One series of pairs of more northeasterly trend lies over the general location of a change from moderately thick to very thick volcanic units that was interpreted from gravity data. Several low amplitude but distinctively shaped anomalies in areas underlain primarily by sedimentary strata indicate the presence of intrusions and faults.

  1. Report of early site suitability evaluation of the potential repository site at Yucca Mountain, Nevada; Yucca Mountain Site Characterization Project

    SciTech Connect

    Younker, J.L.; Andrews, W.B.; Fasano, G.A.; Herrington, C.C.; Mattson, S.R.; Murray, R.C.; Ballou, L.B.; Revelli, M.A.; Ducharme, A.R.; Shephard, L.E.; Dudley, W.W.; Hoxie, D.T.; Herbst, R.J.; Patera, E.A.; Judd, B.R.; Docka, J.A.; Rickertsen, L.D.

    1992-01-01

    This study evaluated the technical suitability of Yucca Mountain, Nevada, as a potential site for a mined geologic repository for the permanent disposal of radioactive waste. The evaluation was conducted primarily to determine early in the site characterization program if there are any features or conditions at the site that indicate it is unsuitable for repository development. A secondary purpose was to determine the status of knowledge in the major technical areas that affect the suitability of the site. This early site suitability evaluation (ESSE) was conducted by a team of technical personnel at the request of the Associate Director of the US Department of Energy (DOE) Office of Geologic Disposal, a unit within the DOE`s Office of Civilian Radioactive Waste Management. The Yucca Mountain site has been the subject of such evaluations for over a decade. In 1983, the site was evaluated as part of a screening process to identify potentially acceptable sites. The site was evaluated in greater detail and found suitable for site characterization as part of the Environmental Assessment (EA) (DOE, 1986) required by the Nuclear Waste Policy Act of 1982 (NWPA). Additional site data were compiled during the preparation of the Site Characterization Plan (SCP) (DOE, 1988a). This early site suitability evaluation has considered information that was used in preparing both-documents, along with recent information obtained since the EA and SCP were published. This body of information is referred to in this report as ``current information`` or ``available evidence.``

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

    SciTech Connect

    J.S. Stuckless; D. O'Leary

    2006-09-25

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

  3. Evaluation of geographic information systems for three-dimensional ground-water modeling, Yucca Mountain, Nevada

    USGS Publications Warehouse

    Turner, A. Keith; Ervin, Elisabeth M.; Downey, Joe S.

    1991-01-01

    Fully three-dimensional representations of the geologic system at Yucca Mountain have been developed using a Geoscientific Information System, which is an expansion of a traditional Geographic Information Systems. These advanced, three dimensional, representations of Yucca Mountain are required to adequately evaluate the complex geologic and hydrologic conditions surrounding the site. This Geoscientific Information System will be used to store, analyze, and display site data. The system also will provide a link between geologic and hydrologic data and the numerical ground-water-flow model resulting in more easy testing of hypotheses concerning the conceptual model of the geohydrologic system at Yucca Mountain.

  4. COVE 2A Benchmarking calculations using NORIA; Yucca Mountain Site Characterization Project

    SciTech Connect

    Carrigan, C.R.; Bixler, N.E.; Hopkins, P.L.; Eaton, R.R.

    1991-10-01

    Six steady-state and six transient benchmarking calculations have been performed, using the finite element code NORIA, to simulate one-dimensional infiltration into Yucca Mountain. These calculations were made to support the code verification (COVE 2A) activity for the Yucca Mountain Site Characterization Project. COVE 2A evaluates the usefulness of numerical codes for analyzing the hydrology of the potential Yucca Mountain site. Numerical solutions for all cases were found to be stable. As expected, the difficulties and computer-time requirements associated with obtaining solutions increased with infiltration rate. 10 refs., 128 figs., 5 tabs.

  5. 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.

  6. Public Interaction and Educational Outreach on the Yucca Mountain Project

    SciTech Connect

    A. Benson; Y. Riding

    2002-11-14

    In July 2002, the U.S. Congress approved Yucca Mountain in Nevada as the nation's first long-term geologic repository site for spent nuclear fuel and high-level radioactive waste. This major milestone for the country's high-level radioactive waste disposal program comes after more than twenty years of scientific study and intense public interaction and outreach. This paper describes public interaction and outreach challenges faced by the U.S. Department of Energy's (DOE) Yucca Mountain Project in the past and what additional communication strategies may be instituted following the July 2002 approval by the U.S. Congress to develop the site as the nation's first long-term geologic repository for spent nuclear fuel and high-level radioactive waste. The DOE public involvement activities were driven by two federal regulations--the National Environmental Policy Act (NEPA) and the Nuclear Waste Policy Act (NWPA) of 1982, as amended. The NEPA required that DOE hold public hearings at key points in the development of an Environmental Impact Statement (EIS) and the NWPA required the agency to conduct public hearings in the vicinity of the site prior to making a recommendation regarding the site's suitability. The NWPA also provided a roadmap for how DOE would interact with affected units of government, which include the state of Nevada and the counties surrounding the site. Because the Department anticipated and later received much public interest in this high-profile project, the agency decided to go beyond regulatory-required public involvement activities and created a broad-based program that implemented far-reaching public interaction and outreach tactics. Over the last two decades, DOE informed, educated, and engaged a myriad of interested local, national, and international parties using various traditional and innovative approaches. The Yucca Mountain Project's intensive public affairs initiatives were instrumental in involving the public, which in turn resulted in

  7. Seismicity in the Vicinity of Yucca Mountain, Nevada, for the Period October 1, 2003 to September 30, 2004

    SciTech Connect

    von Seggern, David; Smith, Ken

    2007-10-15

    This report describes the seismicity and earthquake monitoring activities within the Yucca Mountain region during fiscal year 2004 (FY2004 - October 1, 2003, through September 30, 2004) based on operation of the Southern Great Basin Digital Seismic Network (SGBDSN). Network practices and earthquake monitoring conducted at the Nevada Seismological Laboratory (NSL) under DOE directives for prior fiscal years are covered in similar yearly reports (see references). Real-time systems, including regional data telemetry and data management at NSL, provide for the automatic determination of earthquake locations and magnitudes and notification of important earthquakes in the region to UNR staff and DOE management. All waveform and meta-data, including automatic locations, phase arrival information, and analyst reviewed information, are managed through a relational database system allowing quick and reliable evaluation and analysis of ongoing earthquake activity near Yucca Mountain. This network, which contains weak-motion and strong-motion instrumentation, addresses the seismic hazard of the Yucca Mountain area by providing accurate earthquake magnitudes for earthquake recurrence estimates, spatial hypocentral control to very low magnitudes for identifying and assessing active faults and verifying tectonic models, true ground motions over the complete range of expected earthquake amplitudes for developing predictive models, and earthquake source information for characterizing active faulting. The Nevada Seismological Laboratory operated a 30-station monitoring network within a ring of approximately 50 km radius around Yucca Mountain during FY2004. This year showed the second-lowest seismic moment rate in the NTS and Yucca Mountain region for any fiscal year reporting period since prior to the 1992 M 5.6 Little Skull Mountain (LSM) earthquake. A total of 2180 earthquakes were located for FY2004. The largest event during FY2004 was M 2.99 and there were only 12 earthquakes

  8. Smelters as Analogs for a Volcanic Eruption at Yucca Mountain

    SciTech Connect

    Ross, Benjamin

    2004-11-15

    The distribution of trace radionuclides in secondary metal smelters provides an analog for spent fuel released from packages during a volcanic eruption. The fraction of the inventory of a radionuclide that would be released into the air in a volcanic eruption is called the dust partitioning factor. In consequence analyses of a volcanic eruption at Yucca Mountain, a value of one has been used for this parameter for all elements. This value is too high for the refractory elements. Reducing the dust partitioning factor for refractory elements to a value equal to the fraction of the magma that becomes ash would still yield conservative estimates of how much radioactivity would be released in an eruption.

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

    SciTech Connect

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

    1989-12-31

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

  10. Evolution of the unsaturated zone testing at Yucca Mountain.

    PubMed

    Wang, J S Y; Bodvarsson, G S

    2003-01-01

    The evaluation of the Yucca Mountain site has evolved from intensive surface-based investigations in the early 1980s to current focus on testing in underground drifts. Different periods of site characterization activities and prominent issues concerning the unsaturated zone (UZ) are summarized. Data collection activities have evolved from mapping of faults and fractures to estimation of percolation through tuff layers, and to quantification of seepage into drifts. Evaluation of discrete flow paths in drifts has led to fracture-matrix interaction and matrix diffusion tests over different scales. The effects of tuff interfaces and local faults are evaluated in fractured-welded and porous-nonwelded units. Mobilization of matrix water and redistribution of moisture are measured in thermal tests. Lessons learned from underground tests are used to focus on processes needed for additional quantification. Migration through the drift shadow zone and liquid flow through faults are two important issues that have evolved from current knowledge. PMID:12714299

  11. Thermally induced natural convection effects in Yucca Mountain drifts.

    PubMed

    Webb, Stephen W; Francis, Nicholas D; Dunn, Sandra Dalvit; Itamura, Michael T; James, Darryl L

    2003-01-01

    Thermally induced natural convection from the heat produced by emplaced waste packages is an important heat and mass transfer mechanism within the Yucca Mountain Project (YMP) drifts. Various models for analyzing natural convection have been employed. The equivalent porous medium approach using Darcy's law has been used in many YMP applications. However, this approach has questionable fidelity, especially for turbulent flow conditions. Computational fluid dynamics (CFD), which is based on the fundamental Navier-Stokes equations, is currently being evaluated as a technique to calculate thermally induced natural convection in YMP. Data-model comparisons for turbulent flow conditions show good agreement of CFD predictions with existing experiments including YMP-specific data. PMID:12714318

  12. Summary report on the geochemistry of Yucca Mountain and environs

    SciTech Connect

    Daniels, W.R.; Wolfsberg, K.; Rundberg, R.S.

    1982-12-01

    This report gives a detailed description of work at Los Alamos that will help resolve geochemical issues pertinent to siting a high-level nuclear waste repository in tuff at Yucca Mountain, Nevada. It is necessary to understand the properties and setting of the host tuff because this rock provides the first natural barrier to migration of waste elements from a repository. The geochemistry of tuff is being investigated with particular emphasis on retardation processes. This report addresses the various aspects of sorption by tuff, physical and chemical makeup of tuff, diffusion processes, tuff/groundwater chemistry, waste element chemistry under expected repository conditions, transport processes involved in porous and fracture flow, and geochemical and transport modeling.

  13. Total-System Performance Assessment for the Yucca Mountain Site

    SciTech Connect

    M.L. Wilson

    2001-12-13

    Yucca Mountain, Nevada, is under consideration as a potential site for a repository for high-level radioactive waste. Total-system performance-assessment simulations are performed to evaluate the safety of the site. Features, events, and processes have been systematically evaluated to determine which ones are significant to the safety assessment. Computer models of the disposal system have been developed within a probabilistic framework, including both engineered and natural components. Selected results are presented for three different total-system simulations, and the behavior of the disposal system is discussed. The results show that risk is dominated by igneous activity at early times, because the robust waste-package design prevents significant nominal (non-disruptive) releases for tens of thousands of years or longer. The uncertainty in the nominal performance is dominated by uncertainties related to waste-package corrosion at early times and by uncertainties in the natural system, most significantly infiltration, at late times.

  14. Factors limiting microbial activity in volcanic tuff at Yucca Mountain

    SciTech Connect

    Kieft, T.L.; Kovacik, W.P.; Taylor, J.

    1996-09-01

    Samples of tuff aseptically collected from 10 locations in the Exploratory Shaft Facility at the site of the proposed high-level nuclear waste repository at Yucca Mountain, Nevada Test Site were analyzed for microbiological populations, activities, and factors limiting microbial activity. Radiotracer assays ({sup 14}C-labeled organic substrate mineralization), direct microscopic counts, and plate counts were used. Radiolabeled substrates were glucose, acetate, and glutamate. Radiotracer experiments were carried out with and without moisture and inorganic nutrient amendments to determine factors limiting to microbial activities. Nearly all samples showed the presence of microorganisms with the potential to mineralize organic substrates. Addition of inorganic nutrients stimulated activities in a small number of samples. The presence of viable microbial communities within the tuff has implications for transport of contaminants.

  15. Evolution of the unsaturated zone testing at Yucca Mountain

    SciTech Connect

    Wang, J.S.Y.; Bodvarsson, G.S.

    2002-09-01

    The evaluation of the Yucca Mountain site has evolved from intensive surface based investigations in the early 1980s to current focus on testing in underground drifts. Different periods of site-characterization activities and prominent issues concerning the unsaturated zone are summarized. Data-collection activities have evolved from mapping of faults and fractures, to estimation of percolation through tuff layers, and to quantification of seepage into drifts. Evaluation of discrete flow paths in drifts has led to fracture-matrix interaction and matrix diffusion tests over different scales. The effects of tuff interfaces and local faults are evaluated in fractured-welded and porous-nonwelded units. Mobilization of matrix water and redistribution of moisture are measured in thermal tests. Lessons learned from underground tests are used to focus on processes needed for additional quantification. Migration through the drift shadow zone and liquid flow through faults are two important issues that have evolved from current knowledge.

  16. A tunnel boring system for the Yucca Mountain Project

    SciTech Connect

    Short, S.N.

    1994-12-31

    Design of the Yucca Mountain Project (YMP) tunnel boring machine (TBM) and backup began in June of 1993, with fabrication, machining and light assembly proceeding through to the end of the year. The original specifications for the project were contained in the request for quote for the YMP TBM and in Construction & Tunneling Services proposal document. As with all complex custom assignments, much of the finer details of the definition of the final scope of delivery was concurrent with the design effort itself. The summation of this effort is described in this paper. The major technical scope of the machine delivery is defined by the parameters listed in TABLE 1. Within the confines of the installed power and design excavation rates, the final product has been tailored to suit the particular needs of the project.

  17. Infiltration at yucca mountain, nevada, traced by 36Cl

    NASA Astrophysics Data System (ADS)

    Norris, A. E.; Wolfsberg, K.; Gifford, S. K.; Bentley, H. W.; Elmore, D.

    1987-11-01

    Measurements of chloride and 36Cl in soils from two locations near Yucca Mountain, Nevada, have been used to trace the infiltration of precipitation in this arid region. The results show that the 36Cl fallout from nuclear-weapons testing formed a well-defined peak at one location, with a maximum 36Cl/Cl ratio 0.5 m below the surface. The structure of the 36Cl bomb pulse at the other location was much more complex, and the quantity of 36Cl in the bomb pulse was < 1% of the 6 × 10 12 atoms {36Cl }/{m 2} in the bomb pulse at the first location. The data indicate hydrologic activity subsequent to the 36Cl bomb-pulse fallout at one location, but none at the other location.

  18. Infiltration at Yucca Mountain, Nevada, traced by {sup 36}Cl

    SciTech Connect

    Norris, A.E.; Wolfsberg, K.; Gifford, S.K.; Bentley, H.W.; Elmore, D.

    1987-04-01

    Measurements of chloride and {sup 36}Cl in soils from two locations near Yucca Mountain, Nevada, have been used to trace the infiltration of precipitation in this arid region. The results show that the {sup 36}Cl fallout from nuclear weapons testing formed a well-defined peak at one location, with a maximum 0.5m below the surface. The structure of the {sup 36}Cl bomb pulse at the other location was much more complex, and quantity of {sup 36}Cl in the bomb pulse was <1% of the 6 x 10{sup 12} atoms {sup 36}Cl/m{sup 2} in the bomb pulse at the first location. The data indicate hydrologic activity subsequent to the {sup 36}Cl bomb pulse fallout at one location, but none at the other location. 11 refs.

  19. [Paleoclimatology studies for Yucca Mountain site characterization]. Final report

    SciTech Connect

    1996-05-03

    This report consists of two separate papers: Fernley Basin studies; and Influence of sediment supply and climate change on late Quaternary eolian accumulation patterns in the Mojave Desert. The first study involved geologic mapping of late Quaternary sediments and lacustrine features combined with precise control of elevations and descriptions of sediments for each of the major sedimentary units. The second paper documents the response of a major eolian sediment transport system in the east-central Mojave Desert: that which feeds the Kelso Dune field. Information from geomorphic, stratigraphic, and sedimentologic studies of eolian deposits and landforms is combined with luminescence dating of these deposits to develop a chronology of periods of eolian deposition. Both studies are related to site characterization studies of Yucca Mountain and the forecasting of rainfall patterns possible for the high-level radioactive waste repository lifetime.

  20. Illuminating the Decision Path: The Yucca Mountain Site Recommendation

    SciTech Connect

    Knox, E.; Slothouber, L.

    2003-02-25

    On February 14, 2002, U.S. Secretary of Energy Spencer Abraham provided to the President the ''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.'' This Recommendation, along with supporting materials, complied with statutory requirements for communicating a site recommendation to the President, and it did more: in 49 pages, the Recommendation also spoke directly to the Nation, illuminating the methodology and considerations that led toward the decision to recommend the site. Addressing technical suitability, national interests, and public concerns, the Recommendation helped the public understand the potential risks and benefits of repository development and placed those risks and benefits in a meaningful national context.

  1. Geotechnical Issues in Total System Performance Assessments of Yucca Mountain

    SciTech Connect

    HO,CLIFFORD K.; HOUSEWORTH,JIM; WILSON,MICHAEL L.

    1999-12-21

    A Total System Performance Assessment (TSPA) of Yucca Mountain consists of integrated sub-models and analyses of natural and engineered systems. Examples of subsystem models include unsaturated-zone flow and transport, seepage into drifts, coupled thermal hydrologic processes, transport through the engineered barrier system, and saturated-zone flow and transport. The TSPA evaluates the interaction of important processes among these subsystems, and it determines the impact of these processes on the overall performance measures (e.g., dose rate to humans). This paper summarizes the evaluation, abstraction, and combination of these subsystem models in a TSPA calculation, and it provides background on the individual TSPA subsystem components that are most directly impacted by geotechnical issues. The potential impact that geologic features, events, and processes have on the overall performance is presented, and an evaluation of the sensitivity of TSPA calculations to these issues is also provided.

  2. Technical Data Catalog: Yucca Mountain Site Characterization Project. Quarterly supplement

    SciTech Connect

    1995-06-30

    This report presents reference information contained in the Yucca Mountain Project Automated Technical Data Tracking System. The Department of Energy is seeking to design and maintain a geologic repository for the disposal of high-level radioactive wastes. However, before this repository can be built, the DOE must first do a comprehensive site evaluation. This evaluation is subject to many regulations. This report fulfills the reporting requirements of the Site-Specific Procedural Agreement for Geologic Repository to develop and maintain a catalog of data which will be updated and provided to the Nuclear Regulatory Commission on a quarterly basis. This catalog contains: description of data; time, place, and method of acquisition; and where data may be examined.

  3. Aeromagnetic Expression of Buried Basaltic Volcanoes Near Yucca Mountain, Nevada

    USGS Publications Warehouse

    O'Leary, D. W.; Mankinen, E.A.; Blakely, R.J.; Langenheim, V.E.; Ponce, D.A.

    2002-01-01

    A high-resolution aeromagnetic survey has defined a number of small dipolar anomalies indicating the presence of magnetic bodies buried beneath the surface of Crater Flat and the Amargosa Desert. Results of potential-field modeling indicate that isolated, small-volume, highly magnetic bodies embedded within the alluvial deposits of both areas produce the anomalies. Their physical characteristics and the fact that they tend to be aligned along major structural trends provide strong support for the hypothesis that the anomalies reflect buried basaltic volcanic centers. Other, similar anomalies are identified as possible targets for further investigation. High-resolution gravity and ground-magnetic surveys, perhaps along with drilling sources of selected anomalies and radiometric age determinations, can provide valuable constraints in estimating potential volcanic hazard to the potential nuclear waste repository at Yucca Mountain.

  4. Hydrologic property alterations due to elevated temperatures at Yucca Mountain

    SciTech Connect

    Flint, A.L.; Nash, M.H.; Nash, M.S.

    1994-12-31

    Yucca Mountain is currently being evaluated as a potential site for a high level nuclear waste repository. The pre-emplacement hydrologic properties of the rock are important in determining the suitability of the site; however, post emplacement thermal loads and associated drying may permanently alter the character of the rock. A preliminary study was undertaken to determine the effects of elevated temperatures on hydrologic properties of the welded Topopah Spring member of the Paintbrush Tuff and a zeolitic, nonwelded tuff from the Tuffaceous Beds of Calico Hills. Rock outcrop samples were collected and dried in the laboratory at different temperatures (up to 400 degrees C). Hydrologic and physical properties -were tested before and after each of the drying cycles.

  5. Saturated Zone Plumes in Volcanic Rock: Implications for Yucca Mountain

    SciTech Connect

    S. Kelkar; R. Roback; B. Robinson; G. Srinivasan; C. Jones; P. Reimus

    2006-02-14

    This paper presents a literature survey of the occurrences of radionuclide plumes in saturated, fractured rocks. Three sites, Idaho National laboratory, Hanford, and Oak Ridge are discussed in detail. Results of a modeling study are also presented showing that the length to width ratio of a plume starting within the repository footprint at the Yucca Mountain Project site, decreases from about 20:1 for the base case to about 4:1 for a higher value of transverse dispersivity, indicating enhanced lateral spreading of the plume. Due to the definition of regulatory requirements, this lateral spreading does not directly impact breakthrough curves at the 18 km compliance boundary, however it increases the potential that a plume will encounter reducing conditions, thus significantly retarding the transport of sorbing radionuclides.

  6. Yucca Mountain Waste Package Closure System Robotic Welding and Inspection System

    SciTech Connect

    C. I. Nichol; D. P. Pace; E. D. Larsen; T. R. McJunkin; D. E. Clark; M. L. Clark; K. L. Skinner; A. D. Watkins; H. B. Smartt

    2011-10-01

    The Waste Package Closure System (WPCS), for the closure of radioactive waste in canisters for permanent storage of spent nuclear fuel (SNF) and high-level waste in the Yucca Mountain Repository was designed, fabricated, and successfully demonstrated at the Idaho National Laboratory (INL). This article focuses on the robotic hardware and tools necessary to remotely weld and inspect the closure lid welds. The system was operated remotely and designed for use in a radiation field, due to the SNF contained in the waste packages being closed.

  7. Site environmental report for calendar year 1994, Yucca Mountain Site, Nye County, Nevada.

    SciTech Connect

    1995-06-01

    The Yucca Mountain Site Characterization office has established an environmental program to ensure that facilities are operated in order to protect, maintain, and restore environmental quality, minimize potential threats to the environment and the public, and comply with environmental policies and US DOE orders. The status of the environmental program has been summarized in this annual report to characterize performance, confirm compliance with environmental requirements, and highlight significant programs and efforts during CY 1994. Monitoring, archaeology, groundwater, ecosystems, tortoise conservation, waste minimization, etc., are covered.

  8. A comparison of two potential repositories: The Waste Isolation Pilot Plant and Yucca Mountain

    SciTech Connect

    Pflum, C.G.

    1994-07-11

    Two repositories in the same country, yet Congress and the DOE manage them differently. While Congress encumbers WIPP with unanticipated oversight and inappropriate regulations, Congress streamlines the commercial repository program and promises improved regulations for Yucca Mountain. While DOE encouraged science at the expense of the WIPP infrastructure, DOE postponed its scientific investigations at Yucca Mountain and constructed an infrastructure, large enough to support an ambitious program that was never realized. Somewhere between WIPP and Yucca Mountain lies an ideal repository program. A program where consistent national policy promotes progress; where lucid regulations inspire confidence; where science and infrastructure are balanced; and where oversight groups do not become the tail that wags the dog. Neither WIPP nor Yucca Mountain are ideal programs, but each has its advantages that approach the ideal. Consistent national policy would steer the ideal repository program in a predictable direction. Here Yucca Mountain has the advantage. Successive legislation has streamlined the siting process and promises better regulations. From the beginning, the ideal program would know its regulators and regulations. Again, Yucca Mountain has the advantage. More familiar with regulators and regulations, the Yucca Mountain program had the foresight not to declare HLW to be hazardous and subject to dual regulations. The ideal program would equitably balance its science and infrastructure. Here neither program has the advantage and could possibly represent extremes. The WIPP`s emphasis on scientific investigations left it with little or no infrastructure to deal with regulations and oversight. A regulatory infrastructure, for example, could have forewarned WIPP that its in situ tests were not relevant to the regulations. On the opposite extreme, the Yucca Mountain`s emphasis on infrastructure left it with less money for scientific investigations.

  9. Practical post-calibration uncertainty analysis: Yucca Mountain, Nevada, USA

    NASA Astrophysics Data System (ADS)

    James, S. C.; Doherty, J.; Eddebbarh, A.

    2009-12-01

    The values of parameters in a groundwater flow model govern the precision of predictions of future system behavior. Predictive precision, thus, typically depends on an ability to infer values of system properties from historical measurements through calibration. When such data are scarce, or when their information content with respect to parameters that are most relevant to predictions of interest is weak, predictive uncertainty may be high, even if the model is “calibrated.” Recent advances help recognize this condition, quantitatively evaluate predictive uncertainty, and suggest a path toward improved predictive accuracy by identifying sources of predictive uncertainty and by determining what observations will most effectively reduce this uncertainty. We demonstrate linear and nonlinear predictive error/uncertainty analyses as applied to a groundwater flow model of Yucca Mountain, Nevada, the US’s proposed site for disposal of high-level radioactive waste. Both of these types uncertainty analysis are readily implemented as an adjunct to model calibration with medium to high parameterization density. Linear analysis yields contributions made by each parameter to a prediction’s uncertainty and the worth of different observations, both existing and yet-to-be-gathered, toward reducing this uncertainty. Nonlinear analysis provides more accurate characterization of the uncertainty of model predictions while yielding their (approximate) probability distribution functions. This paper applies the above methods to a prediction of specific discharge and confirms the uncertainty bounds on specific discharge supplied in the Yucca Mountain Project License Application. Furthermore, Monte Carlo simulations confirm that hydrogeologic units thought to be flow barriers have probability distributions skewed toward lower permeabilities.

  10. Yucca Mountain site characterization project: Site atlas 1997. Part 1

    SciTech Connect

    1997-12-31

    The US Department of Energy (DOE) is conducting site characterization studies at Yucca Mountain, Nevada, to determine if the site is suitable for an underground repository for the permanent disposal of high-level radioactive waste. The Yucca Mountain Project (YMP) Site Atlas is a tool used to cartographically display some of the Geographic Information System (GIS) data in the form of thematic map products. Essentially, the Site Atlas is a compilation of map products that are designed to illustrate the location and extent of site characterization studies. Additionally, the Site Atlas provides maps showing project administrative boundaries and basemaps in the vicinity of the project. The data are current through September 1997. The Atlas is divided into two parts: Part 1 contains GIS maps and supporting characteristic data for geology; stratigraphy; tectonics; volcanism; hydrology; geochemistry; environmental issues; paleontology; repository design; YMP boreholes, trenches, pits, pavements, and exposures; basemap features; and surface-based testing activities, and Part 2 contains 1:6,000- and 1:12,000-scale orthophotography basemaps and orthophotography-based hypsography maps (topographic data). This data is shown at a 50% reduction. The maps and orthophotographs in this Site Atlas are provided to YMP participants as an informational source only and are not for making precise measurements. The Quality Assurance Requirements and Description statement on each map identifies the quality status of the thematic data presented. The Site Atlas is not a comprehensive guide; it does not include all scientific features or studies undertaken for the YMP. The features presented are a small subset of the total work being conducted for the project.

  11. Characterization of hydrogeologic units using matrix properties, Yucca Mountain, Nevada

    USGS Publications Warehouse

    Flint, L.E.

    1998-01-01

    Determination of the suitability of Yucca Mountain, in southern Nevada, as a geologic repository for high-level radioactive waste requires the use of numerical flow and transport models. Input for these models includes parameters that describe hydrologic properties and the initial and boundary conditions for all rock materials within the unsaturated zone, as well as some of the upper rocks in the saturated zone. There are 30 hydrogeologic units in the unsaturated zone, and each unit is defined by limited ranges where a discrete volume of rock contains similar hydrogeologic properties. These hydrogeologic units can be easily located in space by using three-dimensional lithostratigraphic models based on relation- ships of the properties with the lithostratigraphy. Physical properties of bulk density, porosity, and particle density; flow properties of saturated hydraulic conductivity and moisture-retention characteristics; and the state variables (variables describing the current state of field conditions) of saturation and water potential were determined for each unit. Units were defined using (1) a data base developed from 4,892 rock samples collected from the coring of 23 shallow and 8 deep boreholes, (2) described lithostratigraphic boundaries and corresponding relations to porosity, (3) recognition of transition zones with pronounced changes in properties over short vertical distances, (4) characterization of the influence of mineral alteration on hydrologic properties such as permeability and moisture-retention characteristics, and (5) a statistical analysis to evaluate where boundaries should be adjusted to minimize the variance within layers. This study describes the correlation of hydrologic properties to porosity, a property that is well related to the lithostratigraphy and depositional and cooling history of the volcanic deposits and can, therefore, be modeled to be distributed laterally. Parameters of the hydrogeologic units developed in this study and the

  12. Dialogs on the Yucca Mountain controversy. Special report No. 5

    SciTech Connect

    Archambeau, C.B.; Szymanski, J.S.

    1993-03-01

    The recent, 1992, report prepared by the Panel on Coupled Hydrologic/Tectonic/Hydrothermal Systems at Yucca Mountain for the National Research Council of the National Academy of Sciences, entitled Ground Water at Yucca Mountain: How High Can It Rise? has generated critical reviews by Somerville et al. (1992) and by Archambeau (1992). These reviews were submitted as reports to the Nuclear Waste Project Office, State of Nevada by Technology and Resource Assessment Corporation under Contract No. 92/94.0004. A copy of the review report by C. B. Archambeau was also sent to Dr. Frank Press, President of the National Academy of Sciences, along with a cover letter from Dr. Archambeau expressing his concerns with the NRC report and his suggestion that the Academy President consider a re-evaluation of the issues covered by the NRC report. Dr. Press responded in a letter to Dr. Archambeau in February of this year which stated that, based on his staff recommendations and a review report by Dr. J. F. Evernden of the United States Geological Survey, he declined to initiate any further investigations and that, in his view, the NRC report was a valid scientific evaluation which was corroborated by Evernden`s report. He also enclosed, with his letter, a copy of the report he received from his staff. In March of this year Dr. Archambeau replied to the letter and NRC staff report sent by Dr. Press with a detailed point-by-point rebuttal of the NRC staff report to Press. Also, in March, a critical review of Dr. Evernden`s report by M. Somerville was submitted to the Nuclear Waste Project Office of the State of Nevada and this report, along with the earlier review of the NRC report by Somerville et al., was included as attachments to the letter sent to Dr. Press.

  13. Viability assessment of a repository at Yucca Mountain: Overview

    SciTech Connect

    none,

    1998-12-01

    Based on the viability assessment, DOE believes that Yucca Mountain remains a promising site for a geologic repository and that work should proceed to support a decision in 2001 on whether to recommend the site to the President for development as a repository. Over 15 years, extensive research has validated many of the expectations of the scientists who first suggested that remote, desert regions of the Southwest are well-suited for a geologic repository. Engineered barriers can be designed to contain waste for thousands of years, and the natural barriers can delay and dilute any radioactive material that migrates from the waste packages. Current models indicate that the possible radiation exposure to future populations living nearby could be comparable to present-day exposure levels from natural background radiation. Design alternatives that may improve performance and reduce remaining uncertainties are now being evaluated. The performance of a geologic repository over such long time periods--longer than recorded human history--cannot be proven beyond all doubt. Forecasts about future geologic and climatic conditions and engineering estimates of how long the waste packages will remain intact cannot be directly validated. The mathematical models used in the performance assessment are subject to uncertainties that can be reduced but never completely eliminated. The Nuclear Regulatory Commission's general standard for meeting geologic repository regulatory criteria and objectives is reasonable assurance. While considerable uncertainties remain today, DOE believes that reasonable assurance should be achievable in the licensing process after the planned work is completed. The DOE believes, therefore, that ongoing work at Yucca Mountain should proceed as planned.

  14. Results of Chemical Analyses in Support of Yucca Mountain Studies

    SciTech Connect

    Daniels, Jeanette

    2007-12-11

    Ground water monitoring for the Nye County Early Warning Drilling Program (NCEWDP) was established to monitor underground water sources of the area and to protect communities surrounding the Nevada Test Site (NTS) from potential radionuclide contamination of these water sources. It provides hydrological information pertaining to groundwater flow patterns and recharge issues in the vicinity of Yucca Mountain. The Harry Reid Center for Environmental Studies (HRC) obtained groundwater samples from select NCEWDP wells shown in Figure 1. These samples were analyzed for major cations, major anions, trace elements, rare earth elements, alkalinity, pH and conductivity. These geochemical results can be used to evaluate the degree of interaction between the aquifers sampled, leading to a thorough mapping of the aquifer system. With increased analysis down gradient of the Yucca Mountain area, evaluations can identify viable groundwater flow paths and establish mixing of the groundwater systems. Tracer tests provide insight into groundwater flow characteristics and transport processes of potential contaminants. These tests are important for contaminant migration issues including safe disposal of hazardous and radioactive materials and remediation of potentially released contaminants. At a minimum, two conservative (non-sorbing) tracers with different diffusion coefficients are used for each tracer test. The tracer test performed under this cooperative agreement utilized fluorinated benzoic acids and halides as conservative tracers. The tracers are of differing size and have differing rates of diffusion into the rock. Larger molecules can not enter the pore spaces that are penetrated by the smaller molecules, therefore larger tracers will travel faster through thegroundwater system. Identical responses of the two tracers indicate no appreciable diffusion into pores of the aquifer system tuff. For the Nye County Tracer Tests, the HRC provided chemical analysis for the tracer

  15. Hydrogeology of the unsaturated zone, Yucca Mountain, Nevada

    SciTech Connect

    Montazer, P.; Wilson, W.E.

    1985-12-31

    The unsaturated volcanic tuff beneath Yucca Mountain, Nevada, is being evaluated by the US Department of Energy as a host rock for a potential mined geologic repository for high-level radioactive waste. Assessment of site suitability needs an efficient and focused investigative program. A conceptual hydrogeologic model that simulates the flow of fluids through the unsaturated zone at Yucca Mountain was developed to guide the program and to provide a basis for preliminary assessment of site suitability. The study was made as part of the Nevada Nuclear Waste Storage Investigations Project of the US Department of Energy. Thickness of the unsaturated zone is about 1640 to 2460 feet (500 to 750 meters). Based on physical properties, the rocks in the unsaturated zone are grouped for the purpose of this paper into five informal hydrogeologic units. From top to bottom these units are: Tiva Canyon welded unit, Paintbrush nonwelded unit. Topopah Spring welded unit, Calico Hills nonwelded unit, and Crater Flat unit. Welded units have a mean fracture density of 8 to 40 fractures per unit cubic meter, mean matrix porosities of 12 to 23%, matrix hydraulic conductivities with geometric means ranging from 6.5 x 10{sup -6} to 9.8 x 10{sup -6} foot per day (2 x 10{sup -6} to 3 x 10{sup -6} meter per day), and bulk hydraulic conductivities of 0.33 to 33 feet per day (0.1 to 10 meters per day). The nonwelded units have a mean fracture density of 1 to 3 fractures per unit cubic meter, mean matrix porosities of 31 to 46%, and saturated hydraulic conductivities with geometric means ranging from 2.6 x 10{sup -5} to 2.9 x 10{sup -2} foot per day (8 x 10{sup -6} to 9 x 10{sup -3} meter per day). 15 refs., 4 figs., 1 tab.

  16. Word images as policy instruments: Lessons from the Yucca Mountain Controversey

    SciTech Connect

    Conary, J.S.; Soden, D.L.; Carns, D.E.

    1993-08-01

    A study is described which explores word images which have developed about nuclear issues by Nevadans. The study is based on results of a survey conducted regarding issues related to the Yucca Mountain repository.

  17. Environmental assessment overview, Yucca Mountain site, Nevada Research and Development Area, Nevada

    SciTech Connect

    1986-05-01

    In February 1983, the US Department of Energy (DOE) identified the Yucca Mountain site in Nevada as one of nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. The site is in the Great Basin, which is one of five distinct geohydrologic settings considered for the first repository. To determine their suitability, the Yucca Mountain site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE`s General Guidelines for the Recommendations of Sites for the Nuclear Waste Repositories. On the basis of the evaluations reported in this EA, the DOE has found that the Yucca Mountain site is not disqualified under the guidelines. On the basis of these findings, the DOE is nominating the Yucca Mountain site as one of five sites suitable for characterization. 3 figs.

  18. Gravity and magnetic investigations of the Ghost Dance and Solitario Canyon faults, Yucca Mountain, Nevada

    SciTech Connect

    Ponce, D.A.; Langenheim, V.E.

    1995-12-31

    Ground magnetic and gravity data collected along traverses across the Ghost Dance and Solitario Canyon faults on the eastern and western flanks, respectively, of Yucca Mountain in southwest Nevada are interpreted. These data were collected as part of an effort to evaluate faulting in the vicinity of a potential nuclear waste repository at Yucca Mountain. Gravity and magnetic data and models along traverses across the Ghost Dance and Solitario Canyon faults show prominent anomalies associated with known faults and reveal a number of possible concealed faults beneath the eastern flank of Yucca Mountain. The central part of the eastern flank of Yucca Mountain is characterized by several small amplitude anomalies that probably reflect small scale faulting.

  19. Ecology, ethics, and professional environmental practice: The Yucca Mountain, Nevada, project as a case study

    SciTech Connect

    Malone, C.R.

    1995-09-01

    The US Department of Energy (DOE) is proposing to develop a geologic repository for disposing of high-level nuclear waste at Yucca Mountain, Nevada. In this commentary, the ecology program for the DOE`s Yucca Mountain Project is discussed from the perspective of state-of-the-art ecosystem analysis, environmental ethics, and standards of professional practice. Specifically at issue is the need by the Yucca Mountain ecology program to adopt an ecosystem approach that encompasses the current strategy based on population biology and community ecology alone. The premise here is that an ecosystem approach is essential for assessing the long-term potential environmental impacts at Yucca Mountain in light of the thermal effects expected to be associated with heat from radioactive decay.

  20. Late Quaternary geomorphology and soils in Crater Flat, Yucca mountain area, southern Nevada

    SciTech Connect

    Peterson, F.F.; Bell, J.W.; Ramelli, A.R.; Dorn, R.I.; Ku, T.L.

    1995-04-01

    Crater Flat is an alluvium-filled structural basin on the west side of Yucca Mountain, Nevada, which is under consideration for a high-level nuclear waste repository. North-trending, late Quaternary faults offset alluvium in Crater Flat both along the canyons of the western flanks of Yucca Mountain and out on the piedmont slope. We believe the initial lack of young offsets at Yucca Mountain was in part due to unrecognized late Quaternary stratigraphy. We hypothesize that alluviation in the Yucca Mountain region was more active during the late Quaternary than previously thought. Several techniques were tried to test this hypothesis. Results are compared with previous soils and surface-exposure dating studies, and correlated to stratigraphy of other late Quaternary units in the southern Nevada, Death Valley, and Mojave Desert areas, and provide new stratigraphic data relevant to understanding climatic-alluvial processes in the Basin and Range Province during the late Quaternary. 76 refs., 7 figs., 6 tabs.

  1. Yucca Mountain Biological Resources Monitoring Program; Progress report, October 1992--December 1993

    SciTech Connect

    1994-05-01

    The US Department of Energy (DOE) is required by the Nuclear Waste Policy Act of (as amended in 1987) to study and characterize the suitability of Yucca Mountain as a potential geologic repository for high-level nuclear waste. During site characterization, the DOE will conduct a variety of geotechnical, geochemical, geological, and hydrological studies to determine the suitability of Yucca Mountain as a potential repository. To ensure that site characterization activities do not adversely affect the environment at Yucca Mountain, a program has been implemented to monitor and mitigate potential impacts and ensure activities comply with applicable environmental regulations. This report describes the activities and accomplishments of EG&G Energy Measurements, Inc. (EG&G/EM) from October 1992 through December 1993 for six program areas within the Terrestrial Ecosystem component of the environmental program for the Yucca Mountain Site Characterization Project (YMP): Site Characterization Effects, Desert Tortoises (Gopherus agassizii), Habitat Reclamation, Monitoring and Mitigation, Radiological Monitoring, and Biological Support.

  2. Preclosure radiological safety analysis for accident conditions of the potential Yucca Mountain Repository: Underground facilities; Yucca Mountain Site Characterization Project

    SciTech Connect

    Ma, C.W.; Sit, R.C.; Zavoshy, S.J.; Jardine, L.J.; Laub, T.W.

    1992-06-01

    This preliminary preclosure radiological safety analysis assesses the scenarios, probabilities, and potential radiological consequences associated with postulated accidents in the underground facility of the potential Yucca Mountain repository. The analysis follows a probabilistic-risk-assessment approach. Twenty-one event trees resulting in 129 accident scenarios are developed. Most of the scenarios have estimated annual probabilities ranging from 10{sup {minus}11}/yr to 10{sup {minus}5}/yr. The study identifies 33 scenarios that could result in offsite doses over 50 mrem and that have annual probabilities greater than 10{sup {minus}9}/yr. The largest offsite dose is calculated to be 220 mrem, which is less than the 500 mrem value used to define items important to safety in 10 CFR 60. The study does not address an estimate of uncertainties, therefore conclusions or decisions made as a result of this report should be made with caution.

  3. Rock mass mechanical property estimations for the Yucca Mountain Site Characterization Project; Yucca Mountain Site Characterization Project

    SciTech Connect

    Lin, M.; Hardy, M.P.; Bauer, S.J.

    1993-06-01

    Rock mass mechanical properties are important in the design of drifts and ramps. These properties are used in evaluations of the impacts of thermomechanical loading of potential host rock within the Yucca Mountain Site Characterization Project. Representative intact rock and joint mechanical properties were selected for welded and nonwelded tuffs from the currently available data sources. Rock mass qualities were then estimated using both the Norwegian Geotechnical Institute (Q) and Geomechanics Rating (RMR) systems. Rock mass mechanical properties were developed based on estimates of rock mass quality, the current knowledge of intact properties, and fracture/joint characteristics. Empirical relationships developed to correlate the rock mass quality indices and the rock mass mechanical properties were then used to estimate the range of rock mass mechanical properties.

  4. Linear thermal expansion data for tuffs from the unsaturated zone at Yucca Mountain, Nevada; Yucca Mountain Site Characterization Project

    SciTech Connect

    Schwartz, B.M.; Chocas, C.S.

    1992-07-01

    Experiment results are presented for linear thermal expansion measurements on tuffaceous rocks from the unsaturated Yucca Mountain, Nevada. Data were obtained both with and without confining pressure. The accuracy of the unconfined data collected between 50 and 250{degrees}C is better than 1.8 percent, with the precision better than 4.5 ;percent. The accuracy of the unconfined data collected between ambient temperature and 50{degrees}C and is approximately 11 percent deviation from the true value, with a precision of 12 percent of the mean value. Because of experiment design and the lack of information related calibrations, the accuracy and precision of the confined thermal expansion measurements could not be determined.

  5. MISTY ECHO tunnel dynamics experiment data report; Volume 2, Appendices: Yucca Mountain Site Characterization Project

    SciTech Connect

    Phillips, J.S.; Luke, B.A.; Long, J.W.; Lee, J.G.

    1992-04-01

    Tunnel damage resulting from seismic loading is an important issue for the Yucca Mountain nuclear waste repository. The tunnel dynamics experiment was designed to obtain and document ground motions, permanent displacements, observable changes in fracture patterns, and visible damage at ground motion levels of interest to the Yucca Mountain Project. Even though the maximum free-field loading on this tunnel was 28 g, the damage observed was minor. Fielding details, data obtained, and supporting documentation are reported.

  6. MISTY ECHO Tunnel Dynamics Experiment--Data report: Volume 1; Yucca Mountain Site Characterization Project

    SciTech Connect

    Phillips, J.S.; Luke, B.A.; Long, J.W.; Lee, J.G.

    1992-04-01

    Tunnel damage resulting from seismic loading is an important issue for the Yucca Mountain nuclear waste repository. The tunnel dynamics experiment was designed to obtain and document ground motions, permanent displacements, observable changes in fracture patterns, and visible damage at ground motion levels of interest to the Yucca Mountain Project. Even though the maximum free-field loading on this tunnel was 28 g, the damage observed was minor. Fielding details, data obtained, and supporting documentation are reported.

  7. Three-year movement patterns of adult desert tortoises at Yucca Mountain

    SciTech Connect

    Holt, E.A.; Rautenstrauch, K.R.

    1995-12-31

    We studied the home-range size and site fidelity of adult desert tortoises (Gopherus agassizii) at Yucca Mountain, Nevada, during 1992-1994. Of 67 adult tortoises monitored at Yucca Mountain during this period, we evaluated the movements of 22 female and 16 male radiomarked tortoises that were located >50 times during each of the 1992, 1993, and 1994 activity seasons. We measured annual and three-year home range sizes by either 100% minimum convex polygon (MCP) or by 95% cluster.

  8. Thermal analysis of Yucca Mountain commercial high-level waste packages

    SciTech Connect

    Altenhofen, M.K.; Eslinger, P.W.

    1992-10-01

    The thermal performance of commercial high-level waste packages was evaluated on a preliminary basis for the candidate Yucca Mountain repository site. The purpose of this study is to provide an estimate for waste package component temperatures as a function of isolation time in tuff. Several recommendations are made concerning the additional information and modeling needed to evaluate the thermal performance of the Yucca Mountain repository system.

  9. Seismicity in the Vicinity of Yucca Mountain, Nevada, for the Period October 1, 2002, to September 30, 2003

    SciTech Connect

    Smith, Ken; von Seggern, David

    2007-12-04

    Earthquake activity in the Yucca Mountain from October 1, 2002 through September 30, 2003 (FY03) is assessed and compared with previous activity in the region. FY03 is the first reporting year since the 1992 M 5.6 Little Skull Mountain earthquake with no earthquakes greater than M 3.0 within 65 km of Yucca Mountain. In addition, FY03 includes the fewest number of earthquakes greater than M 2.0 in any reporting year since the LSM event. With 3075 earthquakes in the catalog, FY03 represents the second largest number of earthquakes (second to FY02) since FY96 when digital seismic network operations began. The largest event during FY03 was M 2.78 in eastern NTS and there were only 8 earthquakes greater than M 2.0.

  10. Geologic and hydrologic investigations of a potential nuclear waste disposal site at Yucca Mountain, southern Nevada

    SciTech Connect

    Carr, M.D.; Yount, J.C.

    1988-12-31

    Yucca Mountain in southern Nye County, Nevada, has been selected by the United States Department of Energy as one of three potential sites for the nation`s first high-level nuclear waste repository. Its deep water table, closed-basin ground-water flow, potentially favorable host rock, and sparse population have made the Yucca Mountain area a viable candidate during the search for a nuclear waste disposal site. Yucca Mountain, however, lies within the southern Great Basin, a region of known contemporary tectonism and young volcanic activity, and the characterization of tectonism and volcanism remains as a fundamental problem for the Yucca Mountain site. The United States Geological Survey has been conducting extensive studies to evaluate the geologic setting of Yucca Mountain, as well as the timing and rates of tectonic and volcanic activity in the region. A workshop was convened by the Geologic Survey in Denver, Colorado, on August 19, 20, and 21, 1985, to review the scientific progress and direction of these studies. Considerable debate resulted. This collection of papers represents the results of some of the studies presented at the workshop, but by no means covers all of the scientific results and viewpoints presented. Rather, the volume is meant to serve as a progress report on some of the studies within the Geological Survey`s continuing research program toward characterizing the tectonic framework of Yucca Mountain. Individual papers were processed separately for the data base.

  11. Yucca Mountain project canister material corrosion studies as applied to the electrometallurgical treatment metallic waste form

    SciTech Connect

    Keiser, D.D.

    1996-11-01

    Yucca Mountain, Nevada is currently being evaluated as a potential site for a geologic repository. As part of the repository assessment activities, candidate materials are being tested for possible use as construction materials for waste package containers. A large portion of this testing effort is focused on determining the long range corrosion properties, in a Yucca Mountain environment, for those materials being considered. Along similar lines, Argonne National Laboratory is testing a metallic alloy waste form that also is scheduled for disposal in a geologic repository, like Yucca Mountain. Due to the fact that Argonne`s waste form will require performance testing for an environment similar to what Yucca Mountain canister materials will require, this report was constructed to focus on the types of tests that have been conducted on candidate Yucca Mountain canister materials along with some of the results from these tests. Additionally, this report will discuss testing of Argonne`s metal waste form in light of the Yucca Mountain activities.

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

    SciTech Connect

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

    1986-10-01

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

  13. PRESERVATION OF ARCHAEOLOGICAL MATERIALS IN ARID ENVIRONMENTS RELEVANT TO YUCCA MOUNTAIN

    SciTech Connect

    N. Chapman, A. Dansie, C. McCombie

    2006-02-24

    The objective of this study was to evaluate archaeological materials from underground openings or shallow burial in arid environments relevant to Yucca Mountain and to draw conclusions about how their state and their environment of preservation could be of relevance to design and operational aspects of the high-level waste repository. The study has evaluated materials from cultures in the arid regions of the ancient Middle East and compared them with the preservation of ancient materials in dry cave sites in the Great Basin desert area of Nevada. The emphasis has been on materials found in undisturbed underground openings such as caves and un-backfilled tombs. Long-term preservation of such materials in underground openings and the stability of the openings themselves provide useful analogue information that serves as a reference point for considering the operation and evolution of the Yucca Mountain repository. Being able to shed light, by close physical and environmental analogy, on what happens in underground openings over many thousands of years provides valuable underpinning to illustrations of expected system performance and offers pointers towards optimizing repository system and operational design.

  14. 1983 biotic studies of Yucca Mountain, Nevada Test Site, Nye County, Nevada

    SciTech Connect

    O`Farrell, T.P.; Collins, E.

    1984-04-01

    A 27.5-square-mile portion of Yucca Mountain on and adjacent to the US Department of Energy`s Nevada Test Site, Nye County, Nevada, is being considered as a potential location for a national high-level radioactive waste repository. Preliminary geologic and environmental characterization studies have been supported and more extensive studies are planned. Goals of the biotic surveys were to identify species of concern, describe major floral and faunal associations, and assess possible impacts of characterization and operational activities. Floral associations observed were characteristic of either the Mojave or Transition deserts that are widely distributed in southern Nevada. Diversity, in terms of total number of perennial species represented, was higher in Transition Desert associations than in Mojave Desert associations. Canopy coverage of associations fell within the range of reported values, but tended to be more homogeneous than expected. Annual vegetation was found to be diverse only where the frequency of Bromus rubens was low. Ground cover of winter annuals, especially annual grasses, was observed to be very dense in 1983. The threat of range fires on Yucca Mountain was high because of the increased amount of dead litter and the decreased amount of bare ground. Significant variability was observed in the distribution and relative abundance of several small mammal species between 1982 and 1983. Desert tortoise were found in low densities comparable with those observed in 1982. Evidence of recent activity, which included sighting of two live tortoises, was found in five areas on Yucca Mountain. Two of these areas have a high probability of sustaining significant impacts if a repository is constructed. Regeneration of aboveground shrub parts from root crowns was observed in areas damaged in 1982 by seismic testing with Vibroseis machines. These areas, which had been cleared to bare dirt by passage of the machines, also supported lush stands of winter annuals.

  15. Areal power density: A preliminary examination of underground heat transfer in a potential Yucca Mountain repository and recommendations for thermal design approaches; Yucca Mountain Site Characterization Project

    SciTech Connect

    Hertel, E.S. Jr.; Ryder, E.E.

    1991-11-01

    The design of the potential Yucca Mountain repository is subject to many thermal goals related to the compliance of the site with federal regulations. This report summarizes a series of sensitivity studies that determined the expected temperatures near the potential repository. These sensitivity studies were used to establish an efficient loading scheme for the spent fuel canisters and a maximum areal power density based strictly on thermal goals. Given the current knowledge of the site, a design-basis areal power density of 80 kW/acre can be justified based on thermal goals only. Further analyses to investigate the impacts of this design-basis APD on mechanical and operational aspects of the potential repository must be undertaken before a final decision is made.

  16. Magnetic investigations along selected high-resolution seismic traverses in the central block of Yucca Mountain, Nevada

    SciTech Connect

    Ponce, D.A.; Sikora, R.F.; Roberts, C.W.; Morin, R.L.; Halvorson, P.F.

    1995-12-31

    Ground magnetic data collected along several traverses across the central block of Yucca Mountain in southwest Nevada are interpreted. These data were collected as part of an effort to evaluate faulting in the vicinity of a potential nuclear waste repository at Yucca Mountain. Magnetic data and models along traverses across the central block of Yucca Mountain reveal anomalies associated with known faults and indicate a number of possible concealed faults beneath the eastern flank of Yucca Mountain. The central part of the eastern flank of Yucca Mountain is characterized by numerous small-amplitude anomalies that probably reflect small-scale faulting. Magnetic modeling of the terrain along the eastern flank of Yucca Mountain indicates that terrain induced magnetic anomalies of about 100 to 150 nT are present along some profiles where steep terrain exists above the magnetometer.

  17. 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.

  18. Environmental Radiation Protection Standards for Yucca Mountain, Nevada

    SciTech Connect

    Clark, R. L.

    2002-02-27

    The Environmental Protection Agency (EPA) has issued radiation protection standards for the potential spent nuclear fuel and high-level radioactive waste disposal system in Yucca Mountain, Nevada. These standards are found in Part 197 of Title 40 of the Code of Federal Regulations (40 CFR Part 197). The Energy Policy Act of 1992 directed, and gave the authority to, EPA to take this action based upon input from the National Academy of Sciences (NAS). The final standards were published in the Federal Register (66 FR 32073) on 13 June 2001. The 40 CFR Part 197 standards have four major parts: (1) individual-protection during storage activities; (2) individual-protection following closure of the repository; (3) human-intrusion; and (4) ground-water protection. The storage standard is 150 microsieverts (Sv) annual committed effective dose equivalent (CEDE) to any member of the general public. The disposal standards are: (1) 150 Sv annual CEDE for the reasonably maximally exposed individual (RMEI) for 10,000 years after disposal; (2) 150 Sv received by the RMEI within 10,000 years after disposal as a result of human intrusion; and (3) the levels of radionuclides in the ground water cannot exceed 40 Sv from beta and gamma emitters, 5 picocuries per liter (pCi/L) of radium-226 and -228, and 15 pCi/L of gross alpha activity. There are also requirements related to the post-10,000-year period, the basis of compliance judgments, and performance assessments. The Agency has published its responses to the comments received, its technical background document, and its economic impact analysis. In addition to printed form, the documents are available on the World Wide Web at http://www.epa.gov/radiation/yucca/index.html.

  19. Tectonic and neotectonic framwork of the Yucca Mountain region, Task 5

    SciTech Connect

    Schweickert, R.A.

    1993-09-30

    Research continued on the tectonic and neotectonics of the Yucca Mountain region. Highlights from projects include: structural studies in Grapevine Mountains, Funeral Mountains, Bullfrog Hills, and Bare Mountain; development of structural models for pre-Middle Miocene normal and strike-slip faulting at Bare Mountain; Paleomagnetic analysis of Paleozoic and Cenozoic units at Bare Mountain; sampling of pegmatites in Bullfrog Hills and Funeral Mountains for U-Pb isotopic analysis; and review and analysis of Mesozoic structure between eastern sierra and Nevada test Site.

  20. Communicating A Controversial and Complex Project to the Public: Yucca Mountain Tours - Real and Virtual Communication

    SciTech Connect

    A.B. Benson; P.V. Nelson; M. d'Ouville

    2000-03-01

    Since 1983, under the Nuclear Waste Policy Act of 1982, as amended (42 U.S.C. 10101 et seq.), the U.S. Department of Energy (the Department) has been investigating a site at Yucca Mountain, Nevada, to determine whether it is suitable for development as the nation's first repository for permanent geologic disposal of spent nuclear fuel and high-level radioactive waste. By far, the largest quantity of waste destined for geologic disposal is spent nuclear fuel from 118 commercial nuclear power reactors at 72 power plant sites and 1 commercial storage site across the United States. Currently, 104 of these reactors are still in operation and generate about 20 percent of the country's electricity. Under standard contracts that DOE executed with the utilities, DOE is to accept spent nuclear fuel from the utilities for disposal. Until that happens, the utilities must safely store their spent nuclear fuel in compliance with Nuclear Regulatory Commission regulations. As of December 1998, commercial spent nuclear fuel containing approximately 38,500 metric tons of heavy metal (MTHM) was stored in 33 states. The balance of the waste destined for geologic disposal in a repository is Department-owned spent nuclear fuel and high-level radioactive waste. The Department's spent nuclear fuel includes naval spent nuclear fuel and irradiated fuel from weapons production, domestic research reactors, and foreign research reactors. For disposal in a geologic repository, high-level radioactive waste would be processed into a solid glass form and placed into approximately 20,000 canisters. No liquid or hazardous wastes regulated under the Resource Conservation and Recovery Act of 1976 would be disposed of in a geologic repository. The difficulty in siting new facilities, particularly those designed as nuclear or nuclear-related facilities, is well documented. In this context, national boundaries are not significant distinguishing barriers. As one publication observed, ''Environmental

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

    SciTech Connect

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

    2002-02-26

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

  2. The Site-Scale Saturated Zone Flow Model for Yucca Mountain

    NASA Astrophysics Data System (ADS)

    Al-Aziz, E.; James, S. C.; Arnold, B. W.; Zyvoloski, G. A.

    2006-12-01

    previous model calibration. Specific discharge at a point 5~km from the repository is also examined and found to be within acceptable uncertainty. The results show that updated model yields a calibration with smaller residuals than the previous model revision while ensuring that flowpaths follow measured gradients and paths derived from hydrochemical analyses. This work was supported by the Yucca Mountain Site Characterization Office as part of the Civilian Radioactive Waste Management Program, which is managed by the U.S. Department of Energy, Yucca Mountain Site Characterization Project. Sandia National Laboratories is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract DE AC04 94AL85000.

  3. TRM performance prediction in Yucca Mountain welded tuff from linear cutter tests

    SciTech Connect

    Gertsch, R.; Ozdemir, L.; Gertsch, L.

    1992-12-31

    Performance predictions were developed for tunnel boring machines operating in welded tuff for the construction of the experimental study facility and the potential nuclear waste repository at Yucca Mountain. The predictions were based on test data obtained from an extensive series of linear cutting tests performed on samples of Topopah Spring welded tuff from the Yucca Mountain Project site. Using the cutter force, spacing, and penetration data from the experimental program, the thrust, torque, power, and rate of penetration were estimated for a 25 ft diameter tunnel boring machine (TBM) operating in welded tuff. Guidelines were developed for the optimal design of the TBM cutterhead to achieve high production rates at the lowest possible excavation costs. The results show that the Topopah Spring welded tuff (TSw2) can be excavated at relatively high rates of advance with state-of-the-art TBMs. The results also show, however, that the TBM torque and power requirements will be higher than estimated based on rock physical properties and past tunneling experience in rock formations of similar strength.

  4. A seismic study of Yucca Mountain and vicinity, southern Nevada; data report and preliminary results

    USGS Publications Warehouse

    Hoffman, L.R.; Mooney, W.D.

    1983-01-01

    From 1980 to 1982, the U.S. Geological Survey conducted seismic refraction studies at the Nevada Test Site to aid in an investigation of the regional crustal structure at a possible nuclear waste repository site near Yucca Mountain. Two regionally distributed deployments and one north-south deployment recorded nuclear events. First arrival times from these deployments were plotted on a location map and contoured to determine traveltime delays. The results indicate delays as large as 0.5 s in the Yucca Mountain and Crater Flat areas relative to the Jackass Flats area. A fourth east-west deployment recorded a chemical explosion and was interpreted using a two-dimensional computer raytracing technique. Delays as high as 0.7 s were observed over Crater Flat and Yucca Mountain. The crustal model derived from this profile indicates that Paleozoic rocks, which outcrop to the east at Skull Mountain and the Calico Hills, and to the west at Bare Mountain, lie at a minimum depth of 3 km beneath part of Yucca Mountain. These results confirm earlier estimates based on the modeling of detailed gravity data. A mid-crustal boundary at 15 ? 2 km beneath Yucca Mountain is evidenced by a prominent reflection recorded beyond 43 km range at 1.5 s reduced time. Other mid-crustal boundaries have been identified at 24 and 30 km and the total crustal thickness is 35 km.

  5. Interpretive geophysical fault map across the central block of Yucca Mountain, Nevada

    SciTech Connect

    Ponce, D.A.

    1996-12-31

    Geophysical data collected along 29 traverses across the central block of Yucca Mountain in southwest Nevada reveal anomalies associated with known fault sand indicate a number of possible concealed faults beneath the eastern flank of Yucca Mountain. Geophysical interpretations indicate that Midway Valley is characterized by several known and previously unknown faults, that the existence of the Yucca Wash fault is equivocal, and that the central part of the eastern flank of Yucca Mountain is characterized by numerous low-amplitude anomalies that probably reflect numerous small-scale faults. Gravity and magnetic data also reveal several large-amplitude anomalies that reflect larger-scale faulting along the margins of the central block.

  6. Igneous Activity at Yucca Mountain: Technical Basis for Decision Making

    NASA Astrophysics Data System (ADS)

    Hinze, W.; Marsh, B.; Weiner, R.; Coleman, N.

    2007-12-01

    Eighty thousand years ago a small-volume basaltic volcano erupted 20 km south of the Department of Energy's (DOE) proposed high-level radioactive waste repository at Yucca Mountain, Nevada. Lathrop Wells is one of the infrequent basaltic volcanoes that have occurred near Yucca Mountain during the past 10 million years. The Advisory Committee on Nuclear Waste and Materials (ACNW&M) has prepared a summary and analysis of the technical views on the nature, likelihood and potential consequences of future igneous activity at the proposed repository. The technical views have been abstracted from public literature and agency reports. Alternate views reflect uncertainties of the igneous processes that have occurred in the region and those that are likely to occur, as well as the interaction of these processes with the proposed repository. There is general agreement that either extrusive or intrusive igneous activity may occur. The extrusive scenario is likely to cause a larger risk and the effect is greatest within the first thousand years. The nature of igneous activity that could occur will probably be similar in composition, structure, and style to the Lathrop Wells volcano. Certain styles of volcanism, like explosive phreatic eruptions (maar volcanism) are not expected because conditions necessary for these do not exist at Yucca Mountain. The volcanic record, particularly during the past 5 million years, suggests a variety of models for evaluating the probability of future igneous activity. The anticipated range of probability of an igneous event intersecting the proposed repository is low, between 1E-9 and 1E-7/yr. An ongoing DOE expert elicitation incorporating the latest geophysical and drilling data will provide an up-to-date, credible estimate of the probability of volcanic intersection. An understanding of the processes involved in interaction between magma and drifts, waste packages, and waste is evolving and providing new insights. As a result, there is limited

  7. Bedrock geologic Map of the Central Block Area, Yucca Mountain, Nye County, Nevada

    SciTech Connect

    W.C. Day; C. Potter; D. Sweetkind; R.P. Dickerson; C.A. San Juan

    1998-09-29

    Bedrock geologic maps form the foundation for investigations that characterize and assess the viability of the potential high-level radioactive waste repository at Yucca Mountain, Nevada. As such, this map focuses on the central block at Yucca Mountain, which contains the potential repository site. The central block is a structural block of Tertiary volcanic rocks bound on the west by the Solitario Canyon Fault, on the east by the Bow Ridge Fault, to the north by the northwest-striking Drill Hole Wash Fault, and on the south by Abandoned Wash. Earlier reconnaissance mapping by Lipman and McKay (1965) provided an overview of the structural setting of Yucca Mountain and formed the foundation for selecting Yucca Mountain as a site for further investigation. They delineated the main block-bounding faults and some of the intrablock faults and outlined the zoned compositional nature of the tuff units that underlie Yucca Mountain. Scott and Bonk (1984) provided a detailed reconnaissance geologic map of favorable area at Yucca Mountain in which to conduct further site-characterization studies. Of their many contributions, they presented a detailed stratigraphy for the volcanic units, defined several other block-bounding faults, and outlined numerous intrablock faults. This study was funded by the U.S. Department of Energy Yucca Mountain Project to provide a detailed (1:6,000-scale) bedrock geologic map for the area within and adjacent to the potential repository area at Yucca Mountain, Nye County, Nevada. Prior to this study, the 1:12,000-scale map of Scott and Bonk (1984) was the primary source of bedrock geologic data for the Yucca Mountain Project. However, targeted detailed mapping within the central block at Yucca Mountain revealed structural complexities along some of the intrablock faults that were not evident at 1:12,000 (Scott and Bonk, 1984). As a result, this study was undertaken to define the character and extent of the dominant structural features in the

  8. Calcite deposits in drill cores USW G-2 and USW GU-3/G-3 at Yucca Mountain, Nevada: Preliminary report

    SciTech Connect

    Vaniman, D.T.

    1994-04-01

    Yucca Mountain is being studied as a potential site for deep geologic disposal of high-level radioactive waste. Should a repository be developed at Yucca Mountain, the preferred location is within the upper unsaturated tuffaceous volcanic rocks. In this location, one factor of concern is the amount and rate of aqueous transport through the unsaturated rocks toward the underlying saturated intervals. Calcite, one of the most recently-formed minerals at Yucca Mountain, is of minor abundance in the unsaturated rocks but is widely distributed. Studies of calcite ages, isotopic systematics, chemistry and petrography could lead to a better understanding of transport processes at Yucca Mountain.

  9. Characterize Framework for Igneous Activity at Yucca Mountain, Nevada

    SciTech Connect

    F. Perry; B. Youngs

    2000-11-06

    The purpose of this Analysis/Model (AMR) report is twofold. (1) The first is to present a conceptual framework of igneous activity in the Yucca Mountain region (YMR) consistent with the volcanic and tectonic history of this region and the assessment of this history by experts who participated in the Probabilistic Volcanic Hazard Analysis (PVHA) (CRWMS M&O 1996). Conceptual models presented in the PVHA are summarized and extended in areas in which new information has been presented. Alternative conceptual models are discussed as well as their impact on probability models. The relationship between volcanic source zones defined in the PVHA and structural features of the YMR are described based on discussions in the PVHA and studies presented since the PVHA. (2) The second purpose of the AMR is to present probability calculations based on PVHA outputs. Probability distributions are presented for the length and orientation of volcanic dikes within the repository footprint and for the number of eruptive centers located within the repository footprint (conditional on the dike intersecting the repository). The probability of intersection of a basaltic dike within the repository footprint was calculated in the AMR ''Characterize Framework for Igneous Activity at Yucca Mountain, Nevada'' (CRWMS M&O 2000g) based on the repository footprint known as the Enhanced Design Alternative [EDA II, Design B (CRWMS M&O 1999a; Wilkins and Heath 1999)]. Then, the ''Site Recommendation Design Baseline'' (CRWMS M&O 2000a) initiated a change in the repository design, which is described in the ''Site Recommendation Subsurface Layout'' (CRWMS M&O 2000b). Consequently, the probability of intersection of a basaltic dike within the repository footprint has also been calculated for the current repository footprint, which is called the 70,000 Metric Tons of Uranium (MTU) No-Backfill Layout (CRWMS M&O 2000b). The calculations for both footprints are presented in this AMR. In addition, the

  10. Modeling Potential Tephra Dispersal at Yucca Mountain, Nevada

    NASA Astrophysics Data System (ADS)

    Hooper, D.; Franklin, N.; Adams, N.; Basu, D.

    2006-12-01

    Quaternary basaltic volcanoes exist within 20 km [12 mi] of the potential radioactive waste repository at Yucca Mountain, Nevada, and future basaltic volcanism at the repository is considered a low-probability, potentially high-consequence event. If radioactive waste was entrained in the conduit of a future volcanic event, tephra and waste could be transported in the resulting eruption plume. During an eruption, basaltic tephra would be dispersed primarily according to the height of the eruption column, particle-size distribution, and structure of the winds aloft. Following an eruption, contaminated tephra-fall deposits would be affected by surface redistribution processes. The Center for Nuclear Waste Regulatory Analyses developed the computer code TEPHRA to calculate atmospheric dispersion and subsequent deposition of tephra and spent nuclear fuel from a potential eruption at Yucca Mountain and to help prepare the U.S. Nuclear Regulatory Commission to review a potential U.S. Department of Energy license application. The TEPHRA transport code uses the Suzuki model to simulate the thermo-fluid dynamics of atmospheric tephra dispersion. TEPHRA models the transport of airborne pyroclasts based on particle diffusion from an eruption column, horizontal diffusion of particles by atmospheric and plume turbulence, horizontal advection by atmospheric circulation, and particle settling by gravity. More recently, TEPHRA was modified to calculate potential tephra deposit distributions using stratified wind fields based on upper atmosphere data from the Nevada Test Site. Wind data are binned into 1-km [0.62-mi]-high intervals with coupled distributions of wind speed and direction produced for each interval. Using this stratified wind field and discretization with respect to height, TEPHRA calculates particle fall and lateral displacement for each interval. This implementation permits modeling of split wind fields. We use a parallel version of the code to calculate expected

  11. Archaelogy of Arid Environment Points to Management Options for Yucca Mountain

    SciTech Connect

    N. Chapman; A. Dansie; C. McCombie

    2006-08-29

    As with all planned repositories for spent fuel, the critical period over which Yucca Mountain needs to provide isolation is the first hundreds to thousands of years after the fuel is emplaced, when it is at its most hazardous. Both the original and the proposed new EPA standards highlight the central importance of this performance period by focusing on repository behavior during the first 10,000 years. Archaeology has a lot to tell us about the behavior of materials and structures over this time period. There have been numerous studies of archaeological artifacts in conditions relevant to the groundwater saturated environments that are a feature of most international geological disposal concepts, but relatively few in arid environments like that of the Nevada desert. However, there is much information to be gleaned, not only from classic archaeological areas in the Middle East and around the Mediterranean but also, perhaps surprisingly to some, from Nevada itself. Our recent study evaluated archaeological materials from underground openings and shallow burial in arid environments relevant to Yucca Mountain, drawing conclusions about how their state and their environment of preservation could help to assess design and operational options for the high-level waste repository.

  12. Evaluation of the Corrosivity of Dust Deposited on Waste Packages at Yucca Mountain, Nevada

    SciTech Connect

    C. Bryan; R. Jarek; T. Wolery; D. Shields; M. Sutton; E. Hardin; D. Barr

    2005-03-18

    Small amounts of dust will be deposited on the surfaces of waste packages in drifts at Yucca Mountain during the operational and the preclosure ventilation periods. Salts present in the dust will deliquesce as the waste packages cool and relative humidity in the drifts increases. In this paper, we evaluate the potential for brines formed by dust deliquescence to initiate and sustain localized corrosion that results in failure of the waste package outer barrier and early failure of the waste package. These arguments have been used to show that dust deliquescence-induced localized or crevice corrosion of the waste package outer barrier (Alloy 22) is of low consequence with respect to repository performance. Measured atmospheric and underground dust compositions are the basis of thermodynamic modeling and experimental studies to evaluate the likelihood of brine formation and persistence, the volume of brines that may form, and the relative corrosivity of the initial deliquescent brines and of brines modified by processes on the waste package surface. In addition, we evaluate several mechanisms that could inhibit or stifle localized corrosion should it initiate. The dust compositions considered include both tunnel dust samples from Yucca Mountain, National Airfall Deposition Program rainout data, and collected windblown dust samples. Also considered is sublimation of ammonium salts, a process that could affect dust composition prior to deliquescence. Ammonium chlorides, nitrates, and even sulfates sublimate readily into ammonia and acid gases, and will be lost from the surface of the waste package prior to deliquescence.

  13. Field trip report: Observations made at Yucca Mountain, Nye County, Nevada. Special report No. 2

    SciTech Connect

    Hill, C.A.

    1993-03-01

    A field trip was made to the Yucca Mountain area on December 5-9, 1992 by Jerry Frazier, Don Livingston, Christine Schluter, Russell Harmon, and Carol Hill. Forty-three separate stops were made and 275 lbs. of rocks were collected during the five days of the field trip. Key localities visited were the Bare Mountains, Yucca Mountain, Calico Hills, Busted Butte, Harper Valley, Red Cliff Gulch, Wahmonie Hills, Crater Flat, and Lathrop Wells Cone. This report only describes field observations made by Carol Hill. Drawings are used rather than photographs because cameras were not permitted on the Nevada Test Site during this trip.

  14. Volcanic hazard studies for the Yucca Mountain project

    SciTech Connect

    Crowe, B.; Harrington, C.; Turrin, B.; Champion, D.; Wells, S.; Perry, F.; McFadden, L.; Renault, C.

    1989-12-31

    Volcanic hazard studies are ongoing to evaluate the risk of future volcanism with respect to siting of a repository for disposal of high-level radioactive waste at the Yucca Mountain site. Seven Quaternary basaltic volcanic centers are located between 8 and 47 km from the outer boundary of the exploration block. The conditional probability of disruption of a repository by future basaltic volcanism is bounded by the range of 10-8 to 10-10 yr-1. These bounds are currently being reexamined based on new developments in the understanding of the evolution of small volume, basaltic volcanic centers including: Many of the volcanic centers exhibit brief periods of eruptive activity separated by longer periods of inactivity, The centers may be active for time spans exceeding 105 yrs, There is a decline in the volume of eruptions of the centers through time, and Small volume eruptions occurred at two of the Quaternary centers during latest Pleistocene or Holocene. The authors classify the basalt centers as polycyclic, and distinguish them from polygenetic volcanoes. Polycyclic volcanism is characterized by small volume, episodic eruptions of magma of uniform composition over time spans of 103 to 105 yrs. magma eruption rates are low and the time between eruptions exceeds the cooling time of the magma volumes.

  15. Testing the Concept of Drift Shadow at Yucca Mountain, Nevada

    SciTech Connect

    J.B. Paces; L.A. Neymark; T. Ghezzehei; P.F. Dobson

    2006-03-10

    If proven, the concept of drift shadow, a zone of reduced water content and slower ground-water travel time beneath openings in fractured rock of the unsaturated zone, may increase performance of a proposed geologic repository for high-level radioactive waste at Yucca Mountain. To test this concept under natural-flow conditions present in the proposed repository horizon, isotopes within the uranium-series decay chain (uranium-238, uranium-234, and thorium-230, or {sup 238}U-{sup 234}U-{sup 230}Th) have been analyzed in samples of rock from beneath four naturally occurring lithophysal cavities. All samples show {sup 234}U depletion relative to parent {sup 238}U, indicating varying degrees of water-rock interaction over the past million years. Variations in {sup 234}U/{sup 238}U activity ratios indicate that depletion of {sup 234}U relative to {sup 238}U can be either smaller or greater in rock beneath cavity floors relative to rock near cavity margins. These results are consistent with the concept of drift shadow and with numerical simulations of meter-scale spherical cavities in fractured tuff. Differences in distribution patterns of {sup 234}U/{sup 238}U activity ratios in rock beneath the cavity floors are interpreted to reflect differences in the amount of past seepage into lithophysal cavities, as indicated by the abundance of secondary mineral deposits present on the cavity floors.

  16. Impact of Quaternary Climate on Seepage at Yucca Mountain, Nevada

    SciTech Connect

    J.F. Whelan; J.B. Paces; L.A. Neymark; A.K. Schmitt; M. Grove

    2006-03-17

    Uranium-series ages, oxygen-isotopic compositions, and uranium contents were determined in outer growth layers of opal and calcite from 0.5- to 3-centimeter-thick mineral coatings hosted by lithophysal cavities in the unsaturated zone at Yucca Mountain, Nevada, the proposed site of a permanent repository for high-level radioactive waste. Micrometer-scale growth layering in the minerals was imaged using a cathodoluminescence detector on a scanning electron microscope. Determinations of the chemistry, ages, and delta oxygen-18 values of the growth layers were conducted by electron microprobe analysis and secondary ion mass spectrometry techniques at spatial resolutions of 1 to about 20 micrometers ({micro}m) and 25 to 40 micrometers, respectively. Growth rates for the last 300 thousand years (k.y.) calculated from about 300 new high-resolution uranium-series ages range from approximately 0.5 to 1.5 {micro}m/k.y. for 1- to 3-centimeter-thick coatings, whereas coatings less than about I-centimeter-thick have growth rates less than 0.5 {micro}m/k.y. At the depth of the proposed repository, correlations of uranium concentration and delta oxygen-18 values with regional climate records indicate that unsaturated zone percolation and seepage water chemistries have responded to changes in climate during the last several hundred thousand years.

  17. Effects of actinide burning on waste disposal at Yucca Mountain

    SciTech Connect

    Hirschfelder, J.

    1992-07-01

    Release rates of 15 radionuclides from waste packages expected to result from partitioning and transmutation of Light-Water Reactor (LWR) and Actinide-Burning Liquid-Metal Reactor (ALMR) spent fuel are calculated and compared to release rates from standard LWR spent fuel packages. The release rates are input to a model for radionuclide transport from the proposed geologic repository at Yucca Mountain to the water table. Discharge rates at the water table are calculated and used in a model for transport to the accessible environment, defined to be five kilometers from the repository edge. Concentrations and dose rates at the accessible environment from spent fuel and wastes from reprocessing, with partitioning and transmutation, are calculated. Partitioning and transmutation of LWR and ALMR spent fuel reduces the inventories of uranium, neptunium, plutonium, americium and curium in the high-level waste by factors of 40 to 500. However, because release rates of all of the actinides except curium are limited by solubility and are independent of package inventory, they are not reduced correspondingly. Only for curium is the repository release rate much lower for reprocessing wastes.

  18. Yucca Mountain Site Characterization Project: Technical Data Catalog quarterly supplement

    SciTech Connect

    1994-03-31

    The March 21, 1993, Department of Energy (DOE)/Nuclear Regulatory Commission (NRC) Site-Specific Procedural Agreement for Geologic Repository Site Investigation and Characterization Program requires the DOE to develop and maintain a catalog of data which will be updated and provided to the NRC at least quarterly. This catalog is to include a description of the data; the time (date), place, and method of acquisition; and where it may be examined. The Yucca Mountain Site Characterization Project (YMP) Technical Data Catalog is published and distributed in accordance with the requirements of the Site-Specific Agreement. The YMP Technical Data Catalog is a report based on reference information contained in the YMP Automated Technical Data Tracking System (ATDT). The reference information is provided by Participants for data acquired or developed in support of the YMP. The Technical Data Catalog is updated quarterly and published in the month following the end of each quarter. A complete revision to the Catalog is published at the end of each fiscal year. Supplements to the end-of-year edition are published each quarter. These supplements provide information related to new data items not included in previous quarterly updates and data items affected by changes to previously published reference information. The Technical Data Catalog, dated September 30, 1993, should be retained as the baseline document for the supplements until the end-of-year revision is published and distributed in October 1994.

  19. Drift natural convection and seepage at the Yucca Mountain repository

    NASA Astrophysics Data System (ADS)

    Halecky, Nicholaus Eugene

    The decay heat from radioactive waste that is to be disposed in the once proposed geologic repository at Yucca Mountain (YM) will significantly influence the moisture conditions in the fractured rock near emplacement tunnels (drifts). Additionally, large-scale convective cells will form in the open-air drifts and will serve as an important mechanism for the transport of vaporized pore water from the fractured rock, from the hot drift center to the cool drift end. Such convective processes would also impact drift seepage, as evaporation could reduce the build up of liquid water at the tunnel wall. Characterizing and understanding these liquid water and vapor transport processes is critical for evaluating the performance of the repository, in terms of water- induced canister corrosion and subsequent radionuclide containment. To study such processes, we previously developed and applied an enhanced version of TOUGH2 that solves for natural convection in the drift. We then used the results from this previous study as a time-dependent boundary condition in a high-resolution seepage model, allowing for a computationally efficient means for simulating these processes. The results from the seepage model show that cases with strong natural convection effects are expected to improve the performance of the repository, since smaller relative humidity values, with reduced local seepage, form a more desirable waste package environment.

  20. Volcanic hazard studies for the Yucca Mountain project

    SciTech Connect

    Crowe, B.; Turrin, B.; Wells, S.; Perry, F.; McFadden, L.; Renault, C.E.; Champion, D.; Harrington, C.

    1989-05-01

    Volcanic hazard studies are ongoing to evaluate the risk of future volcanism with respect to siting of a repository for disposal of high-level radioactive waste at the Yucca Mountain site. Seven Quaternary basaltic volcanic centers are located a minimum distance of 12 km and a maximum distance of 47 km from the outer boundary of the exploration block. The conditional probability of disruption of a repository by future basaltic volcanism is bounded by the range of 10{sup {minus}8} to 10{sup {minus}10} yr{sup {minus}1}. These values are currently being reexamined based on new developments in the understanding of the evaluation of small volume, basaltic volcanic centers including: (1) Many, perhaps most, of the volcanic centers exhibit brief periods of eruptive activity separated by longer periods of inactivity. (2) The centers may be active for time spans exceeding 10{sup 5} yrs, (3) There is a decline in the volume of eruptions of the centers through time, and (4) Small volume eruptions occurred at two of the Quaternary centers during latest Pleistocene or Holocene time. We classify the basalt centers as polycyclic, and distinguish them from polygenetic volcanoes. Polycyclic volcanism is characterized by small volume, episodic eruptions of magma of uniform composition over time spans of 10{sup 3} to 10{sup 5} yrs. Magma eruption rates are low and the time between eruptions exceeds the cooling time of the magma volumes. 25 refs., 2 figs.

  1. Yucca Mountain Site Characterization Project technical data catalog quarterly supplement

    SciTech Connect

    1995-03-31

    The Department of Energy (DOE)/Nuclear Regulatory Commission (NRC) Site-Specific Procedural Agreement for Geologic Repository Site Investigation and Characterization Program requires the DOE to develop and maintain a catalog of data which will be updated and provided to the NRC at least quarterly. This catalog is to include a description of the data; the time (date), place, and method of acquisition; and where the data may be examined. The Yucca Mountain Site Characterization Project (YMP) Technical Data Catalog is published and distributed in accordance with t requirements of the Site-Specific Agreement. The YMP Technical Data Catalog is a report based on reference information contained in the YMP Automated Technical Data Tracking System (ATDT). The reference information is provided by Participants for data acquired or developed in support of the YMP. The Technical Data Catalog is updated quarterly and distributed in the month following the end of each quarter. A complete revision to the catalog is published at the end of each fiscal year. Supplements to the end-of-year edition are published each quarter. These supplements provide information related to new data items not included in previous quarterly updates and data items affected by changes to@ previously published reference information. The Technical Data Catalog, dated September 30, 1994, should be retained as the baseline document for the supplements until the end-of-year revision is published and distributed in October 1995.

  2. Testing the concept of drift shadow at Yucca Mountain, Nevada

    USGS Publications Warehouse

    Paces, J.B.; Neymark, L.A.; Ghezzehei, T.; Dobson, P.F.

    2006-01-01

    If proven, the concept of drift shadow, a zone of reduced water content and slower ground-water travel time beneath openings in fractured rock of the unsaturated zone, may increase performance of a proposed geologic repository for high-level radioactive waste at Yucca Mountain, To test this concept under natural-flow conditions present in the proposed repository horizon, isotopes within the uranium-series decay chain (uranium-238, uranium-234, and thorium-230, or 238U-234U-230Th) have been analyzed in samples of rock from beneath four naturally occurring lithophysal cavities. All rock samples show 234U depletion relative to parent 238U indicating varying degrees of water-rock interaction over the past million years. Variations in 234U/238U activity ratios indicate that depletion of 234U relative to 238U can be either smaller or greater in rock beneath cavity floors relative to rock near cavity margins. These results are consistent with the concept of drift shadow and with numerical simulations of meter-scale spherical cavities in fractured tuff. Differences in distribution patterns of 234U/ 238U activity ratios in rock beneath the cavity floors are interpreted to reflect differences in the amount of past seepage into lithophysal cavities, as indicated by the abundance of secondary mineral deposits present on the cavity floors.

  3. Preliminary capillary hysteresis simulations in fractured rocks, Yucca Mountain, Nevada

    NASA Astrophysics Data System (ADS)

    Niemi, A.; Bodvarsson, G. S.

    1988-12-01

    Preliminary simulations have been carried out to address the question of how hysteretic (history-dependent) capillary pressure-liquid saturation relation may affect the flow and liquid saturation distribution in a fractured rock system. Using a hysteresis model modified from the theoretically based dependent domain model of Mualem (1984), a system consisting of discrete fractures and rock matrix parts was simulated under periodically occurring infiltration pulses. Comparisons were made between the hysteretic case and the non-hysteretic case using the main drying curve alone. Material properties used represent values reported for the densely welded tuffs at Yucca Mountain, Nevada. Since no actual hysteresis measurements were available for the welded tuffs, the necessary data was derived based on information available in the soils literature The strongly hysteretic behavior in the uppermost layer of the matrix along with the overall lower matrix capillary suctions, generated higher fracture flows and a more "smeared" matrix liquid saturation vs. depth distribution for the hysteretic case. While the actual amounts of water being absorbed into the matrix were very similar, the distributions of this absorbed water were different and the matrix was affected up to greater depths in the hysteretic case in comparison to the non-hysteretic case.

  4. Yucca Mountain Site Characterization Project technical data catalog: Quarterly supplement

    SciTech Connect

    1994-12-31

    The Department of Energy (DOE)/Nuclear Regulatory Commission (NRC) Site-Specific Procedural Agreement for Geologic Repository Site Investigation and Characterization Program requires the DOE to develop and maintain a catalog of data which will be updated and provided to the NRC at least quarterly. This catalog is to include a description of the data; the time (date), place, and method of acquisition; and where the data may be examined. The Yucca Mountain Site Characterization Project (YMP) Technical Data Catalog is published and distributed-in accordance with the requirements of the Site-Specific Agreement. The YMP Technical Data Catalog is a report based on reference information contained in the YMP Automated Technical Data Tracking System (ATDT). The reference information is provided by Participants for data acquired or developed in support of the YMP. The Technical Data Catalog is updated quarterly and distributed in the month following the end of each quarter. A complete revision to the catalog is published at the end of each fiscal year. Supplements to the end-of-year edition are published each quarter. These supplements provide information related to new data items not included in previous quarterly updates and data items affected by changes to previously published reference information. The Technical Data Catalog, dated September 30, 1994, should be retained as the baseline document for the supplements until the end-of-year revision is published and distributed in October 1995.

  5. Yucca Mountain Transportation Security Issues: overview and update

    SciTech Connect

    Ballard, J.D.; Halstead, R.J.; Dilger, F.; Collins, H.

    2007-07-01

    This paper examines four aspects of transportation security planning for the proposed geologic repository at Yucca Mountain, Nevada. The authors review the transportation sabotage consequence assessments prepared over the past five years by the United States Department of Energy (DOE), and the State of Nevada Agency for Nuclear Projects (NANP). The authors identify five critical uncertainties in the repository transportation system being developed by DOE, and assess the implications of these uncertainties for shipment security. The authors compare the security findings and recommendations of the recent National Academy of Sciences study of high-level nuclear waste transportation, with the State of Nevada petition for rulemaking (PRM 73-10) filed with the United States Nuclear Regulatory Commission (NRC) in 1999. The authors summarize recent trends in global terrorism and recommend research on alternative assumptions for threat assessments, and recommend that Federal agencies consider social-science based counter-terrorism strategies, such as precursor analysis, and the 'Day After' methodology developed by the Rand Corporation. (authors)

  6. ELECTRICAL IMAGING AT THE LARGE BLOCK TEST YUCCA MOUNTAIN, NEVADA

    SciTech Connect

    A. Ramirez

    2000-10-01

    A monolithic block of densely welded tuff was excavated from a site on Fran Ridge near Yucca Mountain, Nevada so that coupled thermohydrological processes could be studied in a controlled, in situ experiment. A series of heaters were placed in a horizontal plane about 3 m from the top of the 3 m by 3 m by 4.5 m high block. Temperatures were measured at many points within and on the block surface and a suite of other measurements were taken to define the thermal and hydrologic response. Electrical resistance tomography (ERT) was used to map 2 dimensional images of moisture content changes along four planes in the block. The ERT images clearly delineate the drying and wetting of the rockmass during the 13 months of heating and subsequent six months of cool down. The main feature is a prominent dry zone that forms around the heaters then gradually disappears as the rock cools down. Other features include linear anomalies of decreasing moisture content which are fractures dehydrating as the block heats up. There are also examples of compact anomalies of wetting. Some of these appear to be water accumulation in fractures which are draining condensate from the block. Others may be rain water entering a fracture at the top of the block. During cooldown a general rewetting is observed although this is less certain because of poor data quality during this stage of the experiment.

  7. Characterization of a desert soil sequence at Yucca Mountain, NV

    SciTech Connect

    Guertal, W.R.; Hofmann, L.L.; Hudson, D.B.; Flint, A.L.

    1994-12-31

    Morphological descriptions, borehole geophysics, hydraulic properties from samples, and a ponding experiment were used to characterize a layered, heterogeneous, desert soil sequence at Yucca Mountain, Nevada. Nine major horizon units were identified using standard morphologic techniques and borehole geophysics. The borehole geophysical logging data correlated well with the observed horizons from the exposure and/or the corresponding washout zones. In addition, the geophysical logs provide a quantitative estimate of porosity for the horizons with porosity ranging from 25 to 55 percent. As part of an infiltration experiment, over 50,000 liters of water were applied to a 3.5 m diameter ring during a 14 day period. The final wetting depth was 5 meters. When water application was stopped, redistribution allowed water to continue downward to a maximum depth of 7.4 meters in the next several months. Water content measurements made over time indicate that the horizons had a major influence on the flow of water in the soil and may have caused over 80 percent of the water applied to move laterally.

  8. Shallow infiltration processes in arid watersheds at Yucca Mountain, Nevada

    SciTech Connect

    Flint, L.E.; Flint, A.L.; Hevesi, J.A.

    1994-12-31

    A conceptual model of shallow infiltration processes at Yucca Mountain, Nevada, was developed for use in hydrologic flow models to characterize net infiltration (the penetration of the wetting front below the zone influenced by evapotranspiration). The model categorizes the surface of the site into four infiltration zones. These zones were identified as ridgetops, sideslopes, terraces, and active channels on the basis of water-content changes with depth and time. The maximum depth of measured water-content change at a specific site is a function of surface storage capacity, the timing and magnitude of precipitation, evapotranspiration, and the degree of saturation of surficial materials overlying fractured bedrock. Measured water-content profiles for the four zones indicated that the potential for net infiltration is higher when evapotranspiration is low (i.e. winter, cloudy periods), where surface concentration of water is likely to occur (i.e. depressions, channels), where surface storage capacity is low, and where fractured bedrock is close to the surface.

  9. Yucca Mountain Project - Science & Technology Radionuclide Absorbers Development Program Overview

    SciTech Connect

    Hong-Nian Jow; R.C. Moore; K.B. Helean; S. Mattigod; M. Hochella; A.R. Felmy; J. Liu; K. Rosso; G. Fryxell; J. Krumhansl; Y. Wang

    2005-01-14

    The proposed Yucca Mountain repository is anticipated to be the first facility for long-term disposal of commercial spent nuclear fuel and high-level radioactive waste in the United States. The facility, located in the southern Nevada desert, is currently in the planning stages with initial exploratory excavations completed. It is an underground facility mined into the tuffaceous volcanic rocks that sit above the local water table. The focus of the work described in this paper is the development of radionuclide absorbers or ''getter'' materials for neptunium (Np), iodine (I), and technetium (Tc) for potential deployment in the repository. ''Getter'' materials retard the migration of radionuclides through sorption, reduction, or other chemical and physical processes, thereby slowing or preventing the release and transport of radionuclides. An overview of the objectives and approaches utilized in this work with respect to materials selection and modeling of ion ''getters'' is presented. The benefits of the ''getter'' development program to the United States Department of Energy (US DOE) are outlined.

  10. Yucca Mountain Site Characterization Project Technical Data Catalog (Quarterly supplement)

    SciTech Connect

    1993-12-31

    The March 21, 1993, Department of Energy (DOE)/Nuclear Regulatory Commission (NRC) Site-Specific Procedural Agreement for Geologic Repository Site Investigation and Characterization Program requires the DOE to develop and maintain a catalog of data which will be updated and provided to the NRC at least quarterly. This catalog is to include a description of the data; the time (date), place, and method of acquisition; and where it may be examined. The Yucca Mountain Site Characterization Project (YMP) Technical Data Catalog is published and distributed in accordance with the requirements of the Site-Specific Agreement. The YMP Technical Data Catalog is a report based on reference information contained in the YMP Automated Technical Data Tracking System (ATDT). The reference information is provided by Participants for data acquired or developed in support of the YMP. The Technical Data Catalog is updated quarterly and published in the month following the end of each quarter. A complete revision to the Catalog is published at the end of each fiscal year. Supplements to the end-of-year edition are published each quarter. These supplements provide information related to new data items not included in previous quarterly updates and data items affected by changes to previously published reference information. The Technical Data Catalog, dated September 30, 1993, should be retained as the baseline document for the supplements until the end-of-year revision is published and distributed in October 1994.

  11. Shallow infiltration processes in arid watersheds at Yucca Mountain, Nevada

    SciTech Connect

    Flint, L.E.; Flint, A.L. Hevesi, J.A.

    1994-12-31

    A conceptual model of shallow infiltration processes at Yucca Mountain, Nevada, was developed for use in hydrologic flow models to characterize net infiltration (the penetration of the wetting front below the zone influenced by evapotranspiration). The model categorizes the surface of the site into four infiltration zones. These zones were identified as ridgetops, sideslopes, terraces, and active channels on the basis of water-content changes with depth and time. The maximum depth of measured water-content change at a specific site is a function of surface storage capacity, the timing and magnitude of precipitation, evapotranspiration, and the degree of saturation of surficial materials overlying fractured bedrock. Measured water-content profiles for the four zones indicated that the potential for net infiltration is higher when evapotranspiration is low (i.e winter, cloudy periods), where surface concentration of water is likely to occur (i.e. depressions, channels), where surface storage capacity is low, and where fractured bedrock is close to the surface.

  12. Flow calculations for Yucca Mountain groundwater travel time (GWTT-95)

    SciTech Connect

    Altman, S.J.; Arnold, B.W.; Barnard, R.W.; Barr, G.E.; Ho, C.K.; McKenna, S.A.; Eaton, R.R.

    1996-09-01

    In 1983, high-level radioactive waste repository performance requirements related to groundwater travel time were defined by NRC subsystem regulation 10 CFR 60.113. Although DOE is not presently attempting to demonstrate compliance with that regulation, understanding of the prevalence of fast paths in the groundwater flow system remains a critical element of any safety analyses for a potential repository system at Yucca Mountain, Nevada. Therefore, this analysis was performed to allow comparison of fast-path flow against the criteria set forth in the regulation. Models developed to describe the conditions for initiation, propagation, and sustainability of rapid groundwater movement in both the unsaturated and saturated zones will form part of the technical basis for total- system analyses to assess site viability and site licensability. One of the most significant findings is that the fastest travel times in both unsaturated and saturated zones are in the southern portion of the potential repository, so it is recommended that site characterization studies concentrate on this area. Results support the assumptions regarding the importance of an appropriate conceptual model of groundwater flow and the incorporation of heterogeneous material properties into the analyses. Groundwater travel times are sensitive to variation/uncertainty in hydrologic parameters and in infiltration flux at upper boundary of the problem domain. Simulated travel times are also sensitive to poorly constrained parameters of the interaction between flow in fractures and in the matrix.

  13. Yucca Mountain Site Characterization Project Technical Data Catalog (quarterly supplement)

    SciTech Connect

    1993-06-30

    The June 1, 1985, Department of Energy (DOE)/Nuclear Regulatory Commission (NRC) Site-Specific Procedural Agreement for Geologic Repository Site Investigation and Characterization Program requires the DOE to develop and maintain a catalog of data which will be updated and provided to the NRC at least quarterly. This catalog is to include a description of the data; the time (date), place, and method of acquisition; and where it may be examined. The Yucca Mountain Site Characterization Project (YMP) Technical Data Catalog is published and distributed in accordance with the requirements of the Site-Specific Agreement. The YMP Technical Data Catalog is a report based on reference information contained in the YMP Automated Technical Data Tracking System (ATDT). The reference information is provided by Participants for data acquired or developed in support of the YMP. The Technical Data Catalog is updated quarterly and published in the month following the end of each quarter. A complete revision to the Catalog is published at the end of each fiscal year. Supplements to the end-of-year edition are published each quarter. These supplements provide information related to new data items not included in previous quarterly updates and data items affected by changes to previously published reference information. The Technical Data Catalog, dated December 31, 1992, should be retained as the baseline document for the supplements until the end-of-year revision is published and distributed in October 1993.

  14. MRS system study for the repository: Yucca Mountain Site Characterization Project; Volume 1

    SciTech Connect

    Sinagra, T.A.; Harig, R.

    1990-12-01

    The US Department of Energy (DOE), Office of Civilian Radioactive Waste Management (OCRWM), has initiated a waste management system study to identify the impacts of the presence or absence of a monitored retrievable storage facility (hereinafter referred to as ``MRS``) on system costs and program schedules. To support this study, life-cycle cost estimates and construction schedules have been prepared for the surface and underground facilities and operations of a geologic nuclear waste repository at Yucca Mountain, Nye County, Nevada. Nine different operating scenarios (cases) have been identified by OCRWM for inclusion in this study. For each case, the following items are determined: the repository design and construction costs, operating costs, closure and decommissioning costs, required staffing, construction schedules, uncertainties associated with the costs and schedules, and shipping cask and disposal container throughputs. 6 refs., 83 figs., 57 tabs.

  15. MRS system study for the repository: Yucca Mountain Site Characterization Project; Volume 2

    SciTech Connect

    Sinagra, T.A.; Harig, R.

    1990-12-01

    The US Department of Energy (DOE), Office of Civilian Radioactive Waste Management (OCRWM), has initiated a waste management system study to identify the impacts of the presence or absence of a monitored retrievable storage facility (hereinafter referred to as ``MRS``) on system costs and program schedules. To support this study, life-cycle cost estimates and construction schedules have been prepared for the surface and underground facilities and operations geologic nuclear waste repository at Yucca Mountain, Nye County, Nevada. Nine different operating scenarios (cases) have been identified by OCRWM for inclusion in this study. For each case, the following items are determined: the repository design and construction costs, operating costs, closure and decommissioning costs, required staffing, construction schedules, uncertainties associated with the costs and schedules, and shipping cask and disposal container throughputs. This document contains A-D.

  16. Nye County Nevada Perspectives on the State of the Yucca Mountain Project - 12388

    SciTech Connect

    Lacy, Darrell; Voegele, Michael; Jaszczak, Casmier

    2012-07-01

    Responding to the Department of Energy decision to try to withdraw the Yucca Mountain license application and the Administration actions to close down the Yucca Mountain project, Nye County undertook a number of activities to articulate its support for continuing the Yucca Mountain project. The activities included responding to inquiries from federal agencies, including investigations undertaken by the Government Accountability Office addressing other potential uses for the Yucca Mountain site, responding to a Draft Environmental Impact Statement on the possible use of Yucca Mountain for disposal of Greater than Class C wastes, testifying in hearings, and interacting with the President's Blue Ribbon Commission on America's Nuclear Future. The paper summarizes Nye County's position on the Yucca Mountain repository, Nye County's perspectives on the various activities that were developed and considered by the Government Accountability Office, Nye County's concerns with the use of the Nevada National Security Site for Disposal of Greater than Class C Low-Level Radioactive Wastes, testimony of Nye County officials expressing local community support for the Yucca Mountain project, and Nye County's perspectives on recommendations provided by the Blue Ribbon Commission to move the nation's high-level radioactive waste disposal programs forward without consideration of the role Yucca Mountain could have served in those recommendations. Nye County believes that every effort should be made to, at a minimum, fund the Nuclear Regulatory Commission to complete the license application review. Then, if Congress does decide to change the Nuclear Waste Policy Act, there will be valuable information available to support new policy development. This administration contends that Congressional language associated with the FY2010 and FY2011 appropriations and authorization process is sufficient evidence of its intent to terminate the Yucca Mountain repository program. The appropriation

  17. THE DEVELOPMENT OF THE YUCCA MOUNTAIN PROJECT FEATURE, EVENT, AND PROCESS (FEP) DATABASE

    SciTech Connect

    G. Freeze; P. Swift; N. Brodsky

    2000-10-11

    A Total System Performance Assessment for Site Recommendation (TSPA-SR) has recently been completed (CRWMS M&O, 2000b) for the potential high-level waste repository at the Yucca Mountain site. The TSPA-SR is an integrated model of scenarios and processes relevant to the postclosure performance of the potential repository. The TSPA-SR scenarios and model components in turn include representations of all features, events, and processes (FEPs) identified as being relevant (i.e., screened in) for analysis. The process of identifying, classifying, and screening potentially relevant FEPs thus provides a critical foundation for scenario development and TSPA analyses for the Yucca Mountain site (Swift et al., 1999). The objectives of this paper are to describe (a) the identification and classification of the comprehensive list of FEPs potentially relevant to the postclosure performance of the potential Yucca Mountain repository, and (b) the development, structure, and use of an electronic database for storing and retrieving screening information about the inclusion and/or exclusion of these Yucca Mountain FEPs in TSPA-SR. The FEPs approach to scenario development is not unique to the Yucca Mountain Project (YMP). General systematic approaches are summarized in NEA (1992). The application of the FEPs approach in several other international radioactive waste disposal programs is summarized in NEA ( 1999).

  18. Management and research of desert tortoises for the Yucca Mountain Project

    SciTech Connect

    Rautenstrauch, K.R.; Cox, M.K.; Doerr, T.B.; Green, R.A.; Mueller, J.M.; O`Farrell, T.P.; Rakestraw, D.L.

    1991-12-31

    A program has been developed for the Yucca Mountain Project (YMP) to manage and study the desert tortoise (Gopherus agassizi), a threatened species that occurs at low densities at Yucca Mountain. The goals of this program are to better understand the biology and status of the desert tortoise population at Yucca Mountain, assess impacts on tortoises of site characterization (SC) activities, and minimize those impacts. The first steps we took to develop this program were to compile the available information on the biology of tortoises at Yucca Mountain, ascertain what information was lacking, and identify the potential impacts on tortoises of SC. We then developed a technical design that can be used to identify and mitigate direct and cumulative impacts and provide information on tortoise biology. Interrelated studies were developed to achieve these objectives. The primary sampling unit for the impact monitoring studies is radiomarked tortoises. Three populations of tortoises will be sampled: Individuals isolated from disturbances (control), individuals near major SC activities (direct effects treatment and worst-case cumulative effects treatment), and individuals from throughout Yucca Mountain (cumulative effects treatment). Impacts will be studied by measuring and comparing survival, reproduction, movements, habitat use, health, and diet of these tortoises. A habitat quality model also will be developed and the efficacy of mitigation techniques, such as relocating tortoises, will be evaluated.

  19. Management and research of desert tortoises for the Yucca Mountain Project

    SciTech Connect

    Rautenstrauch, K.R.; Cox, M.K.; Doerr, T.B.; Green, R.A.; Mueller, J.M.; O`Farrell, T.P.; Rakestraw, D.L.

    1991-04-01

    A program has been developed for the Yucca Mountain Project (YMP) to manage and study the desert tortoise (Gopherus agassizi), a threatened species that occurs at low densities at Yucca Mountain. The goals of this program are to better understand the biology and status of the desert tortoise population at Yucca Mountain, assess impacts on tortoises of site characterization (SC) activities, and minimize those impacts. The first steps we took to develop this program were to compile the available information on tortoise biology at Yucca Mountain, ascertain what information was lacking, and identify the potential impacts on tortoises of SC. We then developed a technical design for identifying and mitigating direct and cumulative impacts and providing information on tortoise biology. Interrelated studies were developed to achieve these objectives. The primary sampling unit for the impact monitoring studies is radiomarked tortoises. Three populations of tortoises will be sampled: individuals isolated from disturbances (control), individuals near major SC activities (direct effects treatment and worst-case cumulative effects treatment), and individuals from throughout Yucca Mountain (cumulative effects treatment). Impacts will be studied by measuring and comparing survival, reproduction, movements, habitat use, health, and diet of these tortoises. A habitat quality model also will be developed and the efficacy of mitigation techniques, such as relocating tortoises, will be evaluated. 29 refs.

  20. PORE-WATER ISOTOPIC COMPOSITION AND UNSATURATED-ZONE FLOW, YUCCA MOUNTAIN, NEVADA

    SciTech Connect

    C. Yang

    2000-10-23

    Site characterization at Yucca Mountain, Nevada, the site of a potential high-level radioactive waste repository, has included studies of recharge, flow paths, percolation flux, perched water bodies, and chemical compositions of the water in the thick unsaturated zone (UZ). Samples of pore water from cores of two recently drilled boreholes, USW SD-6 near the ridge top of Yucca Mountain and USW WT-24 north of Yucca mountain, were analyzed for isotopic compositions as part of a study by the US Geological Survey (USGS), in cooperation with the US Department of Energy, under Interagency Agreement DE-AI08-97NV12033. The purpose of this report is to interpret {sup 14}C, {delta}{sup 13}C, {sup 3}H, {delta}D and {delta}{sup 18}O isotopic compositions of pore water from the core of boreholes USW SD-6 and USW WT-24 in relation to sources of recharge and flow paths in the UZ at Yucca Mountain. Borehole designation USW SD-6 and USW WT-24 subsequently will be referred to as SD-6 and WT-24. The sources of recharge and flow paths are important parameters that can be used in a UZ flow model, total system performance assessment (TSPA), and the license application (LA) for the potential repository at Yucca Mountain.

  1. Bedrock geologic map of the central block area, Yucca Mountain, Nye County, Nevada

    SciTech Connect

    Day, W.C.; Potter, C.J.; Sweetkind, D.S.; Dickerson, R.P.; San Juan, C.A.

    1998-11-01

    Bedrock geologic maps form the foundation for investigations that characterize and assess the viability of the potential high-level radioactive waste repository at Yucca Mountain, Nevada. This study was funded by the US Department of Energy Yucca Mountain Project to provide a detailed (1:6,000-scale) bedrock geologic map for the area within and adjacent to the potential repository area at Yucca Mountain, Nye County, Nevada. Prior to this study, the 1:12,000-scale map of Scott and Bon, (1984) was the primary source of bedrock geologic data for the Yucca Mountain Project. However, targeted detailed mapping within the central block at Yucca Mountain revealed structural complexities along some of the intrablock faults that were not evident at 1:12,000 (Scott and Bonk, 1984). As a result, this study was undertaken to define the character and extent of the dominant structural features in the vicinity of the potential repository. In addition to structural considerations, ongoing subsurface excavation and geologic mapping within the exploratory Studies Facility (ESF), development of a three-dimensional-framework geologic model, and borehole investigations required use of a constituent stratigraphic system to facilitate surface to underground comparisons. The map units depicted in this report correspond as closely as possible to the proposed stratigraphic nomenclature by Buesch and others (1996), as described here.

  2. Major results of geophysical investigations at Yucca Mountain and vicinity, southern Nevada

    SciTech Connect

    Oliver, H.W.; Ponce, D.A.; Hunter, W.C.

    1995-12-31

    In the consideration of Yucca Mountain as a possible site for storing high level nuclear waste, a number of geologic concerns have been suggested for study by the National Academy of Sciences which include: (1) natural geologic and geochemical barriers, (2) possible future fluctuations in the water table that might flood a mined underground repository, (3) tectonic stability, and (4) considerations of shaking such as might be caused by nearby earthquakes or possible volcanic eruptions. This volume represents the third part of an overall plan of geophysical investigation of Yucca Mountain, preceded by the Site Characterization Plan (SCP; dated 1988) and the report referred to as the Geophysical White Paper, Phase 1, entitled Status of Data, Major Results, and Plans for Geophysical Activities, Yucca Mountain Project (Oliver and others, 1990). The SCP necessarily contained uncertainty about applicability and accuracy of methods then untried in the Yucca Mountain volcano-tectonic setting, and the White Paper, Phase 1, focused on summarization of survey coverage, data quality, and applicability of results. For the most part, it did not present data or interpretation. The important distinction of the current volume lies in presentation of data, results, and interpretations of selected geophysical methods used in characterization activities at Yucca Mountain. Chapters are included on the following: gravity investigations; magnetic investigations; regional magnetotelluric investigations; seismic refraction investigations; seismic reflection investigations; teleseismic investigations; regional thermal setting; stress measurements; and integration of methods and conclusions. 8 refs., 60 figs., 2 tabs.

  3. Expert judgment in assessing radwaste risks: What Nevadans should know about Yucca Mountain; [Final report

    SciTech Connect

    Shrader-Frechette, K.

    1992-06-01

    For phenomena characterized by accurate and largely complete data, quantitative risk assessment (QRA) provides extraordinarily valuable and objective information. However, with phenomena for which the data, models, or probabilities are incomplete or uncertain, QRA may be less useful and more questionable, because its conclusions are typically empirically and theoretically underdetermined. In the face of empirical or theoretical underdetermination, scientists often are forced to make a number of methodological value judgments and inferences about how to estimate and evaluate the associated risks. The purpose of this project is to evaluate instances of methodological value judgments and invalid or imprecise inferences that have occurred in the QRA done for the proposed Yucca Mountain high-level radioactive waste facility. We shall show (1) that questionable methodological value judgments and inferences have occurred in some Yucca Mountain QRA`S; (2) that questionable judgments and inferences, similar to those in the Yucca Mountain studies, have occurred in previous QRA`s done for other radiation-related facilities and have likely caused earlier QRA`s to err in specific ways; and (3) that, because the value judgments and problems associated with some Yucca Mountain QRA`s include repetitions of similar difficulties in earlier studies, therefore the QRA conclusions of some Yucca Mountain analyses are, at best, uncertain.

  4. Mineralogic variation in drill core UE-25 UZ{number_sign}16, Yucca Mountain, Nevada

    SciTech Connect

    Chipera, S.J.; Vaniman, D.T.; Carlos, B.A.; Bish, D.L.

    1995-02-01

    Quantitative X-ray powder diffraction methods have been used to analyze 108 samples from drill core UE-25 UZ{number_sign}16 at Yucca Mountain, Nevada. This drill hole, located within the imbricate fault zone east of the potential Yucca Mountain repository site, confirms the authors` previous knowledge of gross-scale mineral distributions at Yucca Mountain and provides insight into possible shallow pathways for hydrologic recharge into the potential host rock. Analyses of samples from UE-25 UZ{number_sign}16 have shown that the distribution of major zeolitized horizons, of silica phases, and of glassy tuffs are similar to those noted in nearby drill cores. However, the continuous core and closer sample spacing in UE-25 UZ{number_sign}16 provide a more exact determination of mineral stratigraphy, particularly in hydrologically important units such as the Paintbrush bedded tuffs above the Topopah Spring Tuff and in the upper vitrophyre of the Topopah Spring Tuff. The discovery of matrix zeolitization in the devitrified Topopah Spring Tuff of UE25 UZ{number_sign}16 shows that some unexpected mineralogic features can still be encountered in the exploration of Yucca Mountain and emphasizes the importance of obtaining a more complete three-dimensional model of Yucca Mountain mineralogy.

  5. TSPA 1991: An initial total-system performance assessment for Yucca Mountain; Yucca Mountain Site Characterization Project

    SciTech Connect

    Barnard, R.W.; Wilson, M.L.; Dockery, H.A.; Kaplan, P.G.; Eaton, R.R.; Bingham, F.W.; Gauthier, J.H.; Robey, T.H.

    1992-07-01

    This report describes an assessment of the long-term performance of a repository system that contains deeply buried highly radioactive waste; the system is assumed to be located at the potential site at Yucca Mountain, Nevada. The study includes an identification of features, events, and processes that might affect the potential repository, a construction of scenarios based on this identification, a selection of models describing these scenarios (including abstraction of appropriate models from detailed models), a selection of probability distributions for the parameters in the models, a stochastic calculation of radionuclide releases for the scenarios, and a derivation of complementary cumulative distribution functions (CCDFs) for the releases. Releases and CCDFs are calculated for four categories of scenarios: aqueous flow (modeling primarily the existing conditions at the site, with allowances for climate change), gaseous flow, basaltic igneous activity, and human intrusion. The study shows that models of complex processes can be abstracted into more simplified representations that preserve the understanding of the processes and produce results consistent with those of more complex models.

  6. Batch sorption results for neptunium transport through Yucca Mountain tuffs. Yucca Mountain Site Characterization Program milestone 3349

    SciTech Connect

    Triay, I.R.; Cotter, C.R.; Huddleston, M.H.; Leonard, D.E.

    1996-09-01

    We studied the sorption of neptunium onto tuffs characteristic of the proposed nuclear waste repository at Yucca Mountain, Nevada. The neptunium was in the Np(V) oxidation state under oxidizing conditions in groundwaters from two wells located close to the repository site (J-13 and UE-25 p No.1). We used devitrified, vitric, zeolitic (with emphasis on clinoptilolite-rich samples), and calcite-rich tuffs characteristic of the geology of the site. Neptunium sorbed well onto calcite and calcite-rich tuffs, indicating that a significant amount of neptunium retardation can be expected under fractured-flow scenarios because of calcite coating of the fractures. Neptunium sorption onto clinoptilolite-rich zeolitic tuffs in J-13 well water (pH from 7 to 8.5) was moderate, increased with decreasing pH, and correlated to surface area and amount of clinoptilolite. Neptunium sorbed poorly onto zeolitic tuffs from UE-25 p No.1 groundwater (pH from 7 to 9) and onto devitrified and vitric tuffs from J-13 and UE-25 p No.1 waters (pH from 7 to 9). Iron oxides appeared to be passivated in tuffs, not seeming to contribute to the observed neptunium sorption, even though neptunium sorption onto synthetic iron oxide is significant.

  7. Progress report on colloid-facilitated transport at Yucca Mountain: Yucca Mountain site characterization program milestone 3383

    SciTech Connect

    Triay, I.R.; Degueldre, C.; Wistrom, A.O.; Cotter, C.R.; Lemons, W.W.

    1996-06-01

    To assess colloid-facilitated radionuclide transport in groundwaters at the potential nuclear waste repository at Yucca Mountain, it is very important to understand the generation and stability of colloids, including naturally occurring colloids. To this end, we measured the colloid concentration in waters from Well J-13, which is on the order of 106 particles per milliliter (for particle sizes larger than 100 manometers). At this low particle loading, the sorption of radionuclides to colloids would have to be extremely high before the colloids could carry a significant amount of radionuclides from the repository to the accessible environment. We also performed aggregation experiments to evaluate the stability of silica (particle diameter: 85 nm) and clay colloids (particle diameter: 140 nm) as a function of ionic strength in a carbonate-rich synthetic groundwater. When the concentration of electrolyte is increased to induce aggregation, the aggregation is irreversible and the rate of aggregation increases with increasing electrolyte strength. We used autocorrelation photon spectroscopy to estimate the rate of particle aggregation for both types of colloids. By relating the measured aggregation rate to the Smoluchowski rate expression, we determined the stability ratio, W. Aggregation of silica particles and kaolinite clay particles decreased dramatically for an electrolyte concentration, C{sub NaCl}, below 300 mM and 200 mM, respectively.

  8. Environmental Impacts of Transportation to the Potential Repository at Yucca Mountain

    SciTech Connect

    R.L. Sweeney; R. Best; P. Bolton; P. Adams

    2002-01-03

    The 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 analyzes a Proposed Action to construct, operate, monitor, and eventually close a geologic repository for the disposal of spent nuclear fuel and high-level radioactive waste. As part of the Proposed Action, the EIS analyzes the potential impacts of transporting commercial and DOE spent nuclear fuel and high-level radioactive waste to Yucca Mountain from 77 sites across the United States. The analysis includes information on the comparative impacts of transporting these materials by truck and rail and discusses the impacts of building a rail line or using heavy-haul trucks to move rail casks from a mainline railroad in Nevada to the site. This paper provides an overview of the analyses and the potential impacts of these transportation activities. The potential transportation impacts were looked at from two perspectives: transportation of spent nuclear fuel and high-level radioactive waste by legal-weight truck or by rail on a national scale and impacts specific to Nevada from the transportation of these materials from the State borders to the Yucca Mountain site. In order to address the range of impacts that could result from the most likely modes, legal-weight truck and rail, the EIS employed two analytical scenarios--mostly legal-weight truck and mostly rail. Estimated national transportation impacts were based on 24 years of transportation activities. Approximately 8 fatalities could occur from all causes in the nationwide general population from incident-free transportation activities of the mostly legal-weight truck scenario and about 4 from the mostly rail scenario. The analysis examined the radiological consequences under the maximum foreseeable accident scenario and also overall accident risk. The overall accident risk over the 24 year period would be about 0.0002 latent cancer fatality for

  9. Estimation of the impact of water movement from sewage and settling ponds near a potential high level radioactive waste repository in Yucca Mountain, Nevada; Yucca Mountain Site Characterization Project

    SciTech Connect

    Sobolik, S.R.; Fewell, M.E.

    1992-02-01

    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, which may include underground shafts, drifts, and ramps, and the accompanying ponds used for the storage of sewage water and muck water removed from construction operations. The information in this report pertains to the two-dimensional numerical calculations modelling the movement of sewage and settling pond water, and the potential effects of that water on repository performance and underground experiments. This document contains information that has been used in preparing Appendix I of the Exploratory Studies Facility Design Requirements document (ESF DR) for the Yucca Mountain Site Characterization Project.

  10. Making the Postclosure Safety Case for the Proposed Yucca Mountain Repository

    SciTech Connect

    P. Swift; A.V. Luik

    2006-08-28

    The International Atomic Energy Agency (IAEA), in its advisory standard for geological repositories promulgated jointly with the Nuclear Energy Agency (NEA) of the Organization for Economic Co-operation and Development, explicitly distinguishes between the concepts of a safety case and a safety assessment. As defined in the advisory standard, the safety case is a broader set of arguments that provide confidence and substantiate the formal analyses of system safety made through the process of safety assessment. Although the IAEAYs definitions include both preclosure (i.e., operational) safety and post-closure performance in the overall safety assessment and safety case, the emphasis in here is on long-term performance after waste has been emplaced and the repository has been closed. This distinction between pre- and postclosure aspects of the repository is consistent with the U.S. regulatory framework defined by the U.S. Environmental Protection Agency (Chapter 40 of the Code of Federal Regulations, Part 197, or 40 CFR 197) [2] and implemented by the U.S. Nuclear Regulatory Commission (Chapter 10 of the Code of Federal Regulations, Part 63, or 10 CFR 63) [3]. The separation of the pre- and postclosure safety cases is also consistent with the way in which the U.S. Department of Energy has assigned responsibilities for developing the safety case. Bechtel SAIC Company is the Management and Operating contractor responsible for the design and operation of the Yucca Mountain facility and is therefore responsible for the preparation of the preclosure aspects of the safety case. Sandia National Laboratories has lead responsibility for scientific work evaluating post-closure performance, and therefore is responsible for developing the post-closure aspects of the safety case. In the context of the IAEA definitions, both preclosure and postclosure safety, including safety assessment and the safety case, will be documented in the license application being prepared for the

  11. Survey of Yucca Mountain, Forty-Mile Canyon, and Jackass Flats in Nye County, Nevada for desert tortoise, Gopherus agassizii

    SciTech Connect

    Medica, P.A.; O`Farrell, T.P.; Collins, E.

    1981-10-01

    The objective of this brief survey was to determine if G. agassizii is present west of Forty-Mile Canyon in the Yucca Mountain.. area, or along the major access roads which lead through Jackass Flats to Forty-Mile Canyon and Yucca Mountain

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

    SciTech Connect

    N /A

    2002-10-25

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

  13. Repository relevant testing applied to the Yucca Mountain Project

    SciTech Connect

    Bates, J.K.; Woodland, A.B.; Wronkiewicz, D.J.; Cunnane, J.C.

    1990-10-01

    The tuff beds of Yucca Mountain, Nevada, are currently being investigated as a site for the disposal of high-level nuclear waste in an underground repository. If this site is found suitable, the repository would be located in the unsaturated zone above the water table, and a description of the site and the methodology of assessing the performance of the repository are described in the Site Characterization Plan (SCP). While many factors are accounted for during performance assessment, an important input parameter is the degradation behavior of the waste forms, which may be either spent fuel or reprocessed waste contained in a borosilicate glass matrix. To develop the necessary waste form degradation input, the waste package environment needs to be identified. This environment will change as the waste decays and also is a function of the repository design which has not yet been finalized. At the present time, an exact description of the waste package environment is not available. The SCP does provide an initial description of conditions that can be used to guide waste form evaluation. However, considerable uncertainty exists concerning the conditions under which waste form degradation and radionuclide release may occur after the waste package containment barriers are finally breached. The release conditions that are considered to be plausible include (1) a {open_quotes}bathtub{close_quotes} condition in which the waste becomes fully or partially submerged in water that enters the breached container and accumulates to fill the container up to the level of the breach opening, (2) a {open_quotes}wet drip{close_quotes} or {open_quotes}trickle through{close_quotes} condition in which the waste form is exposed to dripping water that enters through the top and exits the bottom of a container with multiple holes, and (3) a {open_quotes}dry{close_quotes} condition in which the waste form is exposed to a humid air environment.

  14. Characterize Framework for Igneous Activity at Yucca Mountain, Nevada

    SciTech Connect

    F. Perry; R. Youngs

    2004-10-14

    The purpose of this scientific analysis report is threefold: (1) Present a conceptual framework of igneous activity in the Yucca Mountain region (YMR) consistent with the volcanic and tectonic history of this region and the assessment of this history by experts who participated in the probabilistic volcanic hazard analysis (PVHA) (CRWMS M&O 1996 [DIRS 100116]). Conceptual models presented in the PVHA are summarized and applied in areas in which new information has been presented. Alternative conceptual models are discussed, as well as their impact on probability models. The relationship between volcanic source zones defined in the PVHA and structural features of the YMR are described based on discussions in the PVHA and studies presented since the PVHA. (2) Present revised probability calculations based on PVHA outputs for a repository footprint proposed in 2003 (BSC 2003 [DIRS 162289]), rather than the footprint used at the time of the PVHA. This analysis report also calculates the probability of an eruptive center(s) forming within the repository footprint using information developed in the PVHA. Probability distributions are presented for the length and orientation of volcanic dikes located within the repository footprint and for the number of eruptive centers (conditional on a dike intersecting the repository) located within the repository footprint. (3) Document sensitivity studies that analyze how the presence of potentially buried basaltic volcanoes may affect the computed frequency of intersection of the repository footprint by a basaltic dike. These sensitivity studies are prompted by aeromagnetic data collected in 1999, indicating the possible presence of previously unrecognized buried volcanoes in the YMR (Blakely et al. 2000 [DIRS 151881]; O'Leary et al. 2002 [DIRS 158468]). The results of the sensitivity studies are for informational purposes only and are not to be used for purposes of assessing repository performance.

  15. Construction monitoring activities in the Yucca Mountain ESF Starter Tunnel

    SciTech Connect

    Pott, J.; Costin, L.S.; Brechtel, C.E

    1993-12-31

    An underground test facility known as the Exploratory Studies Facility (ESF) is planned as part of the characterization of a site for a potential high-level nuclear waste repository at Yucca Mountain, NV. The first part of the ESF that will be constructed is the North Ramp Starter Tunnel (NRST), which will provide a facility for launching the tunnel-boring machine to be used in the construction of the ESF. Geotechnical monitoring activities are planned for the NRST to provide for the collection of data to confirm design concepts and to enhance safety during construction. This paper describes the activities to be conducted and their objectives. The construction monitoring activities are part of a study defined in the In Situ Design Verification Study Plan. The objectives of this study are to (1) monitor and observe the long-term behavior of openings in a range of ground conditions in the repository host rock, and (2) to observe and evaluate the construction of the ESF with respect to implications for repository construction and performance. Initiating geotechnical monitoring activities in the NRST will allow geotechnical data required to confirm adequate design, construction and long term performance to be collected from the very beginning of underground construction. In addition, the planned monitoring is consistent with standard practice for assuring quality and safety during similar rock excavation for civil construction. The geotechnical monitoring activities addressed by this experiment plan are grouped into three tasks: (1) evaluation of mining methods, (2) monitoring of ground support systems and (3) monitoring drift stability. A general description of each of the tasks is presented below.

  16. Characterization of hydrogeologic units using matrix properties, Yucca Mountain, Nevada

    SciTech Connect

    Flint, L.E.

    1998-09-01

    Determination of the suitability of Yucca Mountain, in southern Nevada, as a geologic repository for high-level radioactive waste requires the use of numerical flow and transport models. Input for these models includes parameters that describe hydrologic properties and the initial and boundary conditions for all rock materials within the unsaturated zone, as well as some of the upper rocks in the saturated zone. There are 30 hydrogeologic units in the unsaturated zone, and each unit is defined by limited ranges where a discrete volume of rock contains similar hydrogeologic properties. These hydrogeologic units can be easily located in space by using three-dimensional lithostratigraphic models based on relationships of the properties with the lithostratigraphy. Physical properties of bulk density, porosity, and particle density; flow properties of saturated hydraulic conductivity and moisture-retention characteristics; and the state variables (variables describing the current state of field conditions) of saturation and water potential were determined for each unit. Units were defined using (1) a data base developed from 4,892 rock samples collected from the coring of 23 shallow and 8 deep boreholes, (2) described lithostratigraphic boundaries and corresponding relations to porosity, (3) recognition of transition zones with pronounced changes in properties over short vertical distances, (4) characterization of the influence of mineral alteration on hydrologic properties such as permeability and moisture-retention characteristics, and (5) a statistical analysis to evaluate where boundaries should be adjusted to minimize the variance within layers. This study describes the correlation of hydrologic properties to porosity, a property that is well related to the lithostratigraphy and depositional and cooling history of the volcanic deposits and can, therefore, be modeled to be distributed laterally.

  17. Secondary plant succession on disturbed sites at Yucca Mountain, Nevada

    SciTech Connect

    Angerer, J.P.; Ostler, W.K.; Gabbert, W.D.; Schultz, B.W.

    1994-12-01

    This report presents the results of a study of secondary plant succession on disturbed sites created during initial site investigations in the late 1970s and early 1980s at Yucca Mountain, NV. Specific study objectives were to determine the rate and success of secondary plant succession, identify plant species found in disturbances that may be suitable for site-specific reclamation, and to identify environmental variables that influence succession on disturbed sites. During 1991 and 1992, fifty seven disturbed sites were located. Vegetation parameters, disturbance characteristics and environmental variables were measured at each site. Disturbed site vegetation parameters were compared to that of undisturbed sites to determine the status of disturbed site plant succession. Vegetation on disturbed sites, after an average of ten years, was different from undisturbed areas. Ambrosia dumosa, Chrysothamnus teretifolius, Hymenoclea salsola, Gutierrezia sarothrae, Atriplex confertifolia, Atriplex canescens, and Stephanomeria pauciflora were the most dominant species across all disturbed sites. With the exception of A. dumosa, these species were generally minor components of the undisturbed vegetation. Elevation, soil compaction, soil potassium, and amounts of sand and gravel in the soil were found to be significant environmental variables influencing the species composition and abundance of perennial plants on disturbed sites. The recovery rate for disturbed site secondary succession was estimated. Using a linear function (which would represent optimal conditions), the recovery rate for perennial plant cover, regardless of which species comprised the cover, was estimated to be 20 years. However, when a logarithmic function (which would represent probable conditions) was used, the recovery rate was estimated to be 845 years. Recommendations for future studies and site-specific reclamation of disturbances are presented.

  18. The origin and history of alteration and carbonatization of the Yucca Mountain ignimbrites. Volume I

    SciTech Connect

    Szymanski, J.S.

    1992-04-01

    This document contains Volume I of the report entitled The Origin and History of Alteration and Carbonatization of the Yucca Mountain Ignimbrites by Jerry S. Szymanski and a related correspondence with comments by Donald E. Livingston. In the Great Basin, the flow of terrestrial heat through the crust is affected in part by the flow of fluids. At Yucca Mountain, the role of fluids in crustal heat transport is manifested at the surface by youthful calcretes, sinters, bedrock veins, hydrothermal eruption breccias and hydrothermal alteration. This report discusses evidence for recent metasomatism high in the stratigraphic section at Yucca Mountain. Over the last several hundred years, episodes of calcite emplacement contemporaneous with local mafic volcanism have occurred at intervals that are not long in comparison with the isolation time required for a High-Level Radioactive Waste repository.

  19. Yucca Mountain Site Characterization Project bibliography, January--June 1995. Supplement 4, Add.3: An update

    SciTech Connect

    Stephan, P.M.

    1996-01-01

    Following a reorganization of the Office of Civilian Radioactive Waste Management in 1990, the Yucca Mountain Project was renamed Yucca Mountain Site Characterization Project. The title of this bibliography was also changed to Yucca Mountain Site Characterization Project Bibliography. Prior to August 5, 1988, this project was called the Nevada Nuclear Waste Storage Investigations. This bibliography contains information on this ongoing project that was added to the Department of Energy`s Energy Science and Technology Database from January 1, 1995, through June 30, 1995. The bibliography is categorized by principal project participating organization. Participant-sponsored subcontractor reports, papers, and articles are included in the sponsoring organization`s list. Another section contains information about publications on the Energy Science and Technology Database that were not sponsored by the project but have some relevance to it.

  20. Yucca Mountain site characteriztion project bibliography. Progress Report, 1994--1995

    SciTech Connect

    1996-08-01

    Following a reorganization of the Office of Civilian Radioactive Waste Management in 1990, the Yucca Mountain Project was renamed Yucca Mountain Site Characterization Project. The title of this bibliography was also changed to Yucca Mountain Site Characterization Project Bibliography. Prior to August 5, 1988, this project was called the Nevada Nuclear Waste Storage Investigations. This bibliography contains information on this ongoing project which was added to the Department of Energy`s Energy Science and Technology Database from January 1, 1994, through December 31, 1995. The bibliography is categorized by principal project participating organization. Participant-sponsored subcontractor reports, papers, and articles are included in the sponsoring organization`s list. Another section contains information about publications on the Energy Science and Technology database which were not sponsored by the project but have some relevance to it.

  1. Yucca Mountain Site Characterization Project Bibliography, July--December 1994: An update

    SciTech Connect

    1995-03-01

    Following a reorganization of the Office of Civilian Radioactive Waste Management in 1990, the Yucca Mountain Project was renamed Yucca Mountain Site Charactrization Project. The title of this bibliography was also changed to Yucca Mountain Site Characterization Project Bibliography. Prior to August 5, 1988, this project was called the Nevada Nuclear Waste Storage Investigations. This bibliography contains information on this ongoing project that was added to the Department of Energy`s Science and Technology Database from July 1, 1994 through December 31, 1994. The bibliography is categorized by principal project participating organization. Participant-sponsored subcontractor reports, papers, and articles are included in the sponsoring organization`s list. Another section contains information about publications on the Energy Science and Technology Database that were not sponsored by the project but have some relevance to it.

  2. Site characterization progress report: Yucca Mountain, Nevada, April 1, 1993--September 30, 1993, No. 9

    SciTech Connect

    1994-02-01

    In accordance with requirements of Section 113(b)(3) of the Nuclear Waste Policy Act of 1982, as amended, and 10 CFR 60.18(g), the U.S. Department of Energy has prepared this report on the progress of site characterization activities at Yucca Mountain, Nevada, for the period April 1, 1993, through September 30, 1993. This report is the ninth in a series issued at intervals of approximately six months during site characterization of Yucca Mountain as a possible site for a geologic repository for the permanent disposal of high-level radioactive waste. Also included in this report are activities such as public outreach and international programs that are not formally part of the site characterization process. Information on these activities is provided to report on all aspects of the Yucca Mountain studies.

  3. Yucca Mountain Biological resources monitoring program; Annual report FY89 and FY90

    SciTech Connect

    1991-01-01

    The US Department of Energy (US DOE) is required by the Nuclear Waste Policy Act of 1982 (as amended in 1987) to study and characterize Yucca Mountain as a possible site for a geological repository for high-level radioactive waste. To ensure site characterization activities do not adversely affect the Yucca Mountain area, an environmental program, the Yucca Mountain Biological Resources Monitoring Program, has been implemented monitor and mitigate environmental impacts and to ensure activities comply with applicable environmental laws. Potential impacts to vegetation, small mammals, and the desert tortoise (an indigenous threatened species) are addressed, as are habitat reclamation, radiological monitoring, and compilation of baseline data. This report describes the program in Fiscal Years 1989 and 1990. 12 refs., 4 figs., 17 tabs. (MHB)

  4. Geohydrologic data and models of Rainier Mesa and their implications to Yucca Mountain

    SciTech Connect

    Wang, J.S.Y.; Cook, N.G.W.; Wollenberg, H.A.; Carnahan, C.L.; Javandel, I.; Tsang, C.F.

    1993-01-01

    The geohydrologic data collected at Rainier Mesa provide the only extensive observations in tunnels presently available on flow and transport in tuff units similar to those of a potential nuclear waste repository at Yucca Mountain. This information can, therefore, be of great value in planning the Exploratory Studies Facility (ESF) testing in underground drifts at Yucca Mountain. In this paper, we compare the geohydrologic characteristics of tuff units of these two sites and summarize the hydrochemical data indicating the presence of nearly meteoric water in Rainier Mesa tunnels. A simple analytic model is used to evaluate the possibility of propagating transient pulses of water along fractures or faults through the Paintbrush nonwelded tuff unit to reach the tunnel beds below. The results suggest that fast flow could occur without significant mixing between meteoric fracture water and matrix pore water. The implications of these findings on planning for the ESF Calico Hills study at Yucca Mountain are discussed.

  5. Status of data, major results, and plans for geophysical activities, Yucca Mountain Project

    SciTech Connect

    Oliver, H.W.; Hardin, E.L.; Nelson, P.H.

    1990-07-01

    This report describes past and planned geophysical activities associated with the Yucca Mountain Project and is intended to serve as a starting point for integration of geophysical activities. This report relates past results to site characterization plans, as presented in the Yucca Mountain Site Characterization Plan (SCP). This report discusses seismic exploration, potential field methods, geoelectrical methods, teleseismic data collection and velocity structural modeling, and remote sensing. This report discusses surface-based, airborne, borehole, surface-to-borehole, crosshole, and Exploratory Shaft Facility-related activities. The data described in this paper, and the publications discussed, have been selected based on several considerations; location with respect to Yucca Mountain, whether the success or failure of geophysical data is important to future activities, elucidation of features of interest, and judgment as to the likelihood that the method will produce information that is important for site characterization. 65 refs., 19 figs., 12 tabs.

  6. 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.

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

    SciTech Connect

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

    1996-08-01

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

  8. Department of Energy perspective on high-level waste standards for Yucca Mountain

    SciTech Connect

    Brocoum, S.J.; Gil, A.V.; Van Luik, A.E.; Lugo, M.A.

    1996-07-01

    This paper provides a regulatory perspective from the viewpoint of the potential licensee, the U.S. Department of Energy (DOE), on the National Academy of Sciences (NAS) report on Yucca Mountain standards issued in August 1995, and on how the recommendations in that report should be considered in the development of high-level radioactive waste standards applicable to Yucca Mountain. The paper first provides an overview of the DOE perspective and then discusses several of the issues that are of most importance in the development of the regulatory framework for Yucca Mountain, including both the U.S. Environmental Protection Agency (EPA) standard and the U.S. Nuclear Regulatory Commission (NRC) implementing regulation. These issues include: the regulatory time frame, the risk/dose limit, the definition of the reference biosphere, human intrusion, and natural processes and events.

  9. K/AR dating of clinoptilolite, mordenite, and associated clays from Yucca Mountains, Nevada

    SciTech Connect

    WoldeGabriel, G.

    1993-07-01

    Zeolites are abundant in the geologic record in both continental and marine environments. The purpose of the present study is to evaluate the utility of K-bearing zeolites for dating by the K/Ar method to determine the time of zeolite diagenesis at Yucca Mountain, Nevada (Fig. 1). At Yucca Mountain, K-rich clinoptilolite and possibly mordenite are the only potentially K/Ar dateable secondary minerals present in the zeolite-rich tuffs except for some illite/smectites ({ge}10% illite layers) associated with these minerals. Direct dating of K-rich clinoptilolite, the most abundant zeolite in the altered tuffs, is important to delineate zeolite chronology as part of the site characterization of Yucca Mountain.

  10. Yucca Mountain Site Characterization Project Bibliography, January--June 1993. An update: Supplement 4, Addendum 1

    SciTech Connect

    Stephan, P.M.

    1995-01-01

    Following a reorganization of the Office of Civilian Radioactive Waste Management in 1990, the Yucca Mountain Project was renamed Yucca Mountain Site Characterization Project. The title of this bibliography was also changed to Yucca Mountain Site Characterization Project Bibliography. Prior to August 5, 1988, this project was called the Nevada Nuclear Waste Storage Investigations. This bibliography contains information on this ongoing project that was added to the Department of Energy`s Energy Science and Technology Database from January 1, 1994 through June 30, 1994. The bibliography is categorized by principal project participating organization. Participant-sponsored subcontractor reports, papers,and articles are included in the sponsoring organization`s list. Another section contains information about publications on the Energy Science and Technology Database that were not sponsored by the project but have some relevance to it.

  11. Three dimensional visualization in support of Yucca Mountain Site characterization activities

    SciTech Connect

    Brickey, D.W.

    1992-02-01

    An understanding of the geologic and hydrologic environment for the proposed high-level nuclear waste repository at Yucca Mountain, NV is a critical component of site characterization activities. Conventional methods allow visualization of geologic data in only two or two and a half dimensions. Recent advances in computer workstation hardware and software now make it possible to create interactive three dimensional visualizations. Visualization software has been used to create preliminary two-, two-and-a-half-, and three-dimensional visualizations of Yucca Mountain structure and stratigraphy. The three dimensional models can also display lithologically dependent or independent parametric data. Yucca Mountain site characterization studies that will be supported by this capability include structural, lithologic, and hydrologic modeling, and repository design.

  12. Site characterization progress report: Yucca Mountain, Nevada, October 1, 1992--March 31, 1993, No. 8

    SciTech Connect

    1993-08-01

    In accordance with requirements of Section 113(b)(3) of the Nuclear Waste Policy Act of 1982, as amended, and 10 CFR 60.18(g), the US Department of Energy has prepared this report on the progress of site characterization activities at Yucca Mountain, Nevada, for the period October 1, 1992, through March 31, 1993. This report is the eighth in a series issued at intervals of approximately six months during site characterization of Yucca Mountain as a possible site for a geologic repository for the permanent disposal of high-level radioactive waste. Also included in this report are activities such as public outreach and international programs that are not formally part of the site characterization process. Information on these activities is provided to report on all aspects of the Yucca Mountain studies.

  13. Independent management and financial review, Yucca Mountain Project, Nevada. Final report

    SciTech Connect

    1995-07-15

    The Yucca Mountain Project is one part of the Department of Energy`s Office of Civilian Radioactive Waste Management Program (the Program) which was established by the Nuclear Waste Policy Act of 1982, and as amended in 1987. The Program`s goal is to site the nation`s first geologic repository for the permanent disposal of high-level nuclear waste, in the form of spent fuel rod assemblies, generated by the nuclear power industry and a smaller quantity of Government radioactive waste. The Program, which also encompasses the transportation system and the multipurpose canister system was not the subject of this Report. The subject of this Review was only the Yucca Mountain Project in Nevada. While the Review was directed toward the Yucca Mountain Project rather than the Program as a whole, there are certain elements of the Project which cannot be addressed except through discussion of some Program issues. An example is the Total System Life Cycle Cost addressed in Section 7 of this report. Where Program issues are discussed in this Report, the reader is reminded of the scope limitations of the National Association of Regulatory Utility Commissioners (NARUC) contract to review only the Yucca Mountain Project. The primary scope of the Review was to respond to the specific criteria contained in the NARUC scope of work. In responding to these criteria, the Review Team understood that some interested parties have expressed concern over the requirements of the Nuclear Waste Policy Act relative to the Yucca Mountain Project and the nature of activities currently being carried out by the Department of Energy at the Yucca Mountain Project site. The Review Team has attempted to analyze relevant portions of the Nuclear Waste Policy Act as Amended, but has not conducted a thorough analysis of this legislation that could lead to any specific legal conclusions about all aspects of it.

  14. Calcite/opal deposits at Yucca Mountain, Nevada: Pedogenic or hypogene?

    SciTech Connect

    Hill, C.A.; Schluter, C.M.; Harmon, R.S.

    1994-01-01

    This study is part of the research program of the Yucca Mountain Project intended to provide the State of Nevada with a detailed assessment of the geology and geochemistry of Yucca Mountain and adjacent regions. The purpose of this paper is to consider all of the geological and geochemical data available for the calcite/opal deposits at Yucca Mountain and to ascertain whether this data favors a pedogenic or hyogene origin for these deposits. Far from being of esoteric concern, this subject is of paramount importance to the debate which rages around the suitability of Yucca Mountain as a high-level radioactive waste repository site. It is also the purpose of this paper to serve as a foundation for a lengthy feature article to be submitted for publication in 1994. In addition, a stand has been taken by the National Research Council of the National Academy of Sciences against the upwelling-water model (a vote of 17 to 0 against), and this same panel report has concluded that {open_quotes}there is no compelling evidence for the repetitive flooding of the environment by expulsion of groundwater{close_quotes} and that {open_quotes}instead, the evidence strongly supports the idea that the near-surface mineral deposits resulted from percolating rainwater, which carried soil minerals down into rock fractures{close_quotes}. Based on such information the Department of Energy has stated that it {open_quotes}finds no basis to continue to study the origin of these specific deposits{close_quotes}. This study, based upon many different independent lines of evidence, reaches the opposite conclusion and instead favors a hypogene spring-travertine origin for the controversial calcite/opal deposits at Yucca Mountain. This study recognizes a pedogenic carbonate component at Yucca Mountain, but argues that this component is distinct from, and sometimes intermixed with, the calcite/opal deposits.

  15. Modeling fluid-rock interaction at Yucca Mountain, Nevada; A progress report, April 15, 1992

    SciTech Connect

    Viani, B.E.; Bruton, C.J.

    1992-08-01

    Volcanic rocks at Yucca Mountain, Nevada aie being assessed for their suitability as a potential repository for high-level nuclear waste. Recent progress in modeling fluid-rock interactions, in particular the mineralogical and chemical changes that may accompany waste disposal at Yucca Mountain, will be reviewed in this publication. In Part 1 of this publication, ``Geochemical Modeling of Clinoptilolite-Water Interactions,`` solid-solution and cation-exchange models for the zeolite clinoptilolite are developed and compared to experimental and field observations. At Yucca Mountain, clinoptilolite which is found lining fractures and as a major component of zeolitized tuffs, is expected to play an important role in sequestering radionuclides that may escape from a potential nuclear waste repository. The solid-solution and ion-exchange models were evaluated by comparing predicted stabilities and exchangeable cation distributions of clinoptilolites with: (1) published binary exchange data; (2) compositions of coexisting clinoptilolites and formation waters at Yucca Mountain; (3) experimental sorption isotherms of Cs and Sr on zeolitized tuff, and (4) high temperature experimental data. Good agreement was found between predictions and expertmental data, especially for binary exchange and Cs and Sr sorption on clinoptilolite. Part 2 of this publication, ``Geochemical Simulation of Fluid-Rock Interactions at Yucca Mountain,`` describes preliminary numerical simulations of fluid-rock interactions at Yucca Mountain. The solid-solution model developed in the first part of the paper is used to evaluate the stability and composition of clinciptilolite and other minerals in the host rock under ambient conditions and after waste emplacement.

  16. Engineered materials characterization report for the Yucca Mountain Site Characterization Project. Volume 1, Introduction, history, and current candidates

    SciTech Connect

    Van Konynenburg, R.A.; McCright, R.D.; Roy, A.K.; Jones, D.A.

    1995-08-01

    The purpose of the Yucca Mountain Site Characterization Project is to evaluate Yucca Mountain for its suitability as a potential site for the nation`s first high-level nuclear waste repository. As part of this effort, Lawrence Livermore National Laboratory (LLNL) has been occupied for a number of years with developing and evaluating the performance of waste packages for the potential repository. In recent years this work has been carried out under the guidance of and in collaboration with the Management and Operating contractor for the Civilian Radioactive Waste Management System, TRW Environmental Safety Systems, Inc., which in turn reports to the Office of Civilian Radioactive Waste Management of the US Department of Energy. This report summarizes the history of the selection and characterization of materials to be used in the engineered barrier system for the potential repository at Yucca Mountain, describes the current candidate materials, presents a compilation of their properties, and summarizes available corrosion data and modeling. The term ``engineered materials`` is intended to distinguish those materials that are used as part of the engineered barrier system from the natural, geologic materials of the site.

  17. Evaluation of copper, aluminum bronze, and copper-nickel for YMP [Yucca Mountain Project] container material

    SciTech Connect

    Kass, J.N.

    1989-05-01

    In this presentation, I will discuss our evaluation of the materials copper, 7% aluminum bronze, and 70/30 copper-nickel. These are three of the six materials currently under consideration as potential waste-packaging materials. I should mention that we are also considering alternatives to these six materials. This work is part of the Yucca Mountain Project (YMP), formerly known as the Nevada Nuclear Waste Storage Investigations (NNWSI) Project. The expected-case environment in our proposed vault is quite different from that encountered at the WIPP site or that expected in a Canadian vault. Our proposed site is under a desert mountain, Yucca Mountain, in southern Nevada. The repository itself will be located approximately 700 feet above the water table and 300 to 1200 feet below the surface of the mountain. The variations in these numbers are due to the variations in mountain topography.

  18. Influence of seasonal climatic variability on shallow infiltration at Yucca Mountain

    USGS Publications Warehouse

    Hevesi, Joseph A.; Flint, Alan L.

    1993-01-01

    To analyze infiltration and the redistribution of moisture in alluvial deposits at Yucca Mountain, water content profiles at a 13.5 m deep borehole were measured at monthly intervals using a neutron moisture probe. Increases in water content to a maximum depth of 1.8 m in response to winter season precipitation were noted. Below a depth of 1.8 m, a gradual drying trend was indicated. A simulation study showed that, although small amounts of water may be percolating through the deep nonwetted ones of the profile, the influence of climatic variability on infiltration through thick alluvial deposits at Yucca Mountain is greatly mitigated by evapotranspiration.

  19. Yucca Mountain, Nevada - A Proposed Geologic Repository for High-Level Radioactive Waste (Volume 1) Introduction

    SciTech Connect

    R.A. Levich; J.S. Stuckless

    2006-09-25

    Yucca Mountain in Nevada represents the proposed solution to what has been a lengthy national effort to dispose of high-level radioactive waste, waste which must be isolated from the biosphere for tens of thousands of years. This chapter reviews the background of that national effort and includes some discussion of international work in order to provide a more complete framework for the problem of waste disposal. Other chapters provide the regional geologic setting, the geology of the Yucca Mountain site, the tectonics, and climate (past, present, and future). These last two chapters are integral to prediction of long-term waste isolation.

  20. U and Sr Isotopes in ground water and calcite, Yucca Mountain, Nevada: Evidence against upwelling water

    USGS Publications Warehouse

    Stuckless, J.S.; Peterman, Z.E.; Muhs, D.R.

    1991-01-01

    Hydrogenic calcite and opaline silica deposits in fault zones at Yucca Mountain, Nevada, have created considerable public and scientific controversy because of the possible development of a high-level nuclear waste repository at this location. Strontium and uranium isotopic compositions of hydrogenic materials were used to test whether the veins could have formed by upwelling of deep-seated waters. The vein deposits are isotopically distinct from ground water in the two aquifers that underlie Yucca Mountain, indicating that the calcite could not have precipitated from ground water. The data are consistent with a surficial origin for the hydrogenic deposits.

  1. Yucca Mountain, Nevada - A proposed geologic repository for high-level radioactive waste

    USGS Publications Warehouse

    Levich, R.A.; Stuckless, J.S.

    2006-01-01

    Yucca Mountain in Nevada represents the proposed solution to what has been a lengthy national effort to dispose of high-level radioactive waste, waste which must be isolated from the biosphere for tens of thousands of years. This chapter reviews the background of that national effort and includes some discussion of international work in order to provide a more complete framework for the problem of waste disposal. Other chapters provide the regional geologic setting, the geology of the Yucca Mountain site, the tectonics, and climate (past, present, and future). These last two chapters are integral to prediction of long-term waste isolation. ?? 2007 Geological Society of America. All rights reserved.

  2. Los Alamos National Laboratory Yucca Mountain Project Publications (1979-1996)

    SciTech Connect

    Ruhala, E.R.; Klein, S.H.

    1997-06-01

    This over-350 title publication list reflects the accomplishments of Los Alamos Yucca Mountain Site Characterization Project researchers, who, since 1979, have been conducting multidisciplinary research to help determine if Yucca Mountain, Nevada, is a suitable site for a high-level waste repository. The titles can be accessed in two ways: by year, beginning with 1996 and working back to 1979, and by subject area: mineralogy/petrology/geology, volcanism, radionuclide solubility/ground-water chemistry; radionuclide sorption and transport; modeling/validation/field studies; summary/status reports, and quality assurance.

  3. Applications of in situ cosmogenic nuclides in the geologic site characterization of Yucca Mountain, Nevada

    SciTech Connect

    Gosse, J.C.; Harrington, C.D.; Whitney, J.W.

    1995-12-31

    The gradual buildup of rare isotopes from interactions between cosmic rays and atoms in an exposed rock provides a new method of directly determining the exposure age of rock surfaces. The cosmogenic nuclide method can also provide constraints on erosion rates and the length of time surface exposure was interrupted by burial. Numerous successful applications of the technique have been imperative to the complete surface geologic characterization of Yucca Mountain, Nevada, a potential high level nuclear waste repository. In this short paper, we summarize the cosmogenic nuclide method and describe with examples some the utility of the technique in geologic site characterization. We report preliminary results from our ongoing work at Yucca Mountain.

  4. Los Alamos National Laboratory Yucca Mountain Project publications (1979--1994)

    SciTech Connect

    Bowker, L.M.; Espinosa, M.L.; Klein, S.H.

    1995-11-01

    This over-300 title publication list reflects the accomplishments of Los Alamos Yucca Mountain Site Characterization Project researchers, who, since 1979, have been conducting multidisciplinary research to help determine if Yucca Mountain, Nevada, is a suitable site for a high-level waste repository. The titles can be accessed in two ways: by year, beginning with 1994 and working back to 1979, and by subject area: mineralogy/petrology/geology, volcanism, radionuclide solubility/groundwater chemistry; radionuclide sorption and transport; modeling/validation/field studies; summary/status reports, and quality assurance.

  5. Geophysical characterization of mineral and energy resources at Yucca Mountain and vicinity, Nevada

    SciTech Connect

    Langenheim, V.E.; Oliver, H.W.; Hoover, D.B.

    1991-12-31

    This report was prepared for the Yucca Mountain Project (Department of Energy) as part of the study of the mineral and energy resource potential of the site (Activity 8.3.1.9.2.1.5) under the Human Interference part of the program. Most of the 1991 geophysical scoping activities in the Mineral Resources Study were involved with the acquisition and evaluation of existing data. This report presents an overview of how geophysical data (existing and planned) will aid in the evaluation of the potential for mineral and energy resource potential at Yucca Mountain and vicinity.

  6. Site environmental report for calendar year 1996: Yucca Mountain site, Nye County, Nevada

    SciTech Connect

    1997-11-01

    The environmental program established by the Yucca Mountain Site Characterization Office (YMSCO) has been designed and implemented to protect, maintain, and restore environmental quality, minimize potential threats to the environment and the public, and comply with environmental policies and US Department of Energy (DOE) Orders. In accordance with DOE Order 5400.1, General Environmental Protection Program (DOE, 1990a), to be superseded by DOE Order 231.1 (under review), the status of the Yucca Mountain Site Characterization Project (YMP) environmental program has been summarized in this annual Site Environmental Report (SER) to characterize performance, document compliance with environmental requirements, and highlight significant programs and efforts during calendar year 1996.

  7. Characterization and Prediction of Subsurface Pneumatic PressureVariations at Yucca Mountain, Nevada

    SciTech Connect

    Ahlers, C. Fredrik; Finsterle, Stefan; Bodvarsson, Gudmundur S.

    1998-01-02

    Yucca Mountain, Nevada is being investigated as the proposed site for geologic disposal of high level nuclear waste. A massive data collection effort for characterization of the unsaturated zone is being carried out at the site. The USGS is monitoring the subsurface pressure variations due to barometric pumping in several boreholes. Numerical models are used to simulate the observed subsurface pressure variations. Data inversion is used to characterize the unsaturated system and estimate the pneumatic diffusivity of important geologic features. Blind predictions of subsurface response and subsequent comparison to recorded data have built confidence in the models of Yucca Mountain.

  8. 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.

  9. Burnup Credit Approach Used in the Yucca Mountain License Application

    SciTech Connect

    Scaglione, John M; Wagner, John C

    2010-01-01

    The United States Department of Energy has submitted a license application (LA) for construction authorization of a deep geologic repository at Yucca Mountain, Nevada. The license application is currently under review by the United States Nuclear Regulatory Commission (NRC). This paper will describe the methodology and approach used in the LA to address the issue of criticality and the role of burnup credit during the postclosure period. The most significant and effective measures for prevention of criticality in the repository include multiple redundant barriers that act to isolate fissionable material from water (which can act as a moderator, corrosive agent, and transporter of fissile material); inherent geometry of waste package internals and waste forms; presence of fixed neutron absorbers in waste package internals; and fuel burnup for commercial spent nuclear fuel. A probabilistic approach has been used to screen criticality from the total system performance assessment. Within the probabilistic approach, criticality is considered an event, and the total probability of a criticality event occurring within 10,000 years of disposal is calculated and compared against the regulatory criterion. The total probability of criticality includes contributions associated with both internal (within waste packages) and external (external to waste packages) criticality for each of the initiating events that could lead to waste package breach. The occurrence of and conditions necessary for criticality in the repository have been thoroughly evaluated using a comprehensive range of parameter distributions. A simplified design-basis modeling approach has been used to evaluate the probability of criticality by using numerous significant and conservative assumptions. Burnup credit is used only for evaluations of in-package configurations and uses a combination of conservative and bounding modeling approximations to ensure conservatism. This paper will review the NRC regulatory

  10. Moisture Observations in Sealed Tunnels at Yucca Mountain, Nevada

    NASA Astrophysics Data System (ADS)

    Coleman, N. M.; Winterle, J.; Arlt, H.; Dinwiddie, C.; Fedors, R.

    2002-12-01

    assessments of deep percolation and seepage. The NRC staff believes that long-term empirical observations in sealed tunnels could be an element of a performance confirmation plan for Yucca Mountain.

  11. ASH REDISTRIBUTION FOLLOWING A POTENTIAL VOLCANIC ERUPTION AT YUCCA MOUNTAIN

    SciTech Connect

    J. Pelletier; S. deLong; M.L. Cline; C. Harrington; G. Keating

    2005-08-29

    The redistribution of contaminated tephra by hillslope, fluvial, and pedologic processes is a poorly-constrained but important aspect of evaluating the radiological dose from an unlikely volcanic eruption at Yucca Mountain (YM). To better evaluate this hazard, we developed a spatially distributed, numerical model of tephra redistribution that integrates contaminated tephra from hill slopes and active channels, mixes it with clean sediment in the channel system, distributes it on the fan, and migrates it into the soil column. The model is coupled with an atmospheric dispersion model that predicts the deposition of radioactive waste-contaminated tephra at specified grid points. The redistribution model begins in the upper Fortymile Wash drainage basin where it integrates the tephra deposited on steep slopes and active channel beds within a GIS framework. The Fortymile Wash drainage basin is the focus of this model because tephra from only this basin reaches the Fortymile Wash alluvial fan by fluvial processes, and it is on this fan where the radiological dose to a hypothetical individual is compared to the regulatory standard (via additional biosphere models). The dilution effect of flood scour, mixing, and re-deposition within the upper basin is modeled using a dilution-mixing model widely used in the contaminant-transport literature. The accuracy of this model is established by comparing the model prediction with tephra concentrations measured in channels draining the Lathrop Wells volcanic center. The model combines the contaminated tephra transported from the upper basin with the tephra deposited directly on the fan as primary fallout. On the Fortymile Wash fan, channels and interchannel-divide areas are divided on the basis of soil-geomorphic mapping according to whether they are Holocene or Pleistocene in age. This approach allows the model to incorporate the effects of channel migration on the fan within the past 10,000 yr. The model treats the redistribution

  12. Chlorine-36 alidation Study at Yucca Mountain, Nevada

    SciTech Connect

    J. Paces

    2006-08-28

    The amount, spatial distribution, and velocity of water percolating through the unsaturated zone (UZ) at Yucca Mountain, Nevada, are important issues for assessing the performance of the proposed deep geologic repository for spent nuclear fuel and high-level radioactive waste. To help characterize the nature and history of UZ flow, isotopic studies were initiated in 1995, using rock samples collected from the Miocene ash-flow tuffs in the Exploratory Studies Facility (ESF), an 8-km-long tunnel constructed along the north-south extent of the repository block, and the Enhanced Characterization of the Repository Block (ECRB) Cross Drift, a 2.5-km-long tunnel constructed across the repository block (Figure 1-1, Sources: Modified from DOE 2002 [Figure 1-14] and USBR 1996). Scientists from Los Alamos National Laboratory (LANL) analyzed for chlorine-36 ({sup 36}Cl) in salts leached from whole-rock samples collected from tunnel walls and subsurface boreholes, and scientists from the U.S. Geological Survey (USGS) analyzed for isotopes of oxygen, carbon, uranium, lead, thorium, and strontium in secondary minerals collected from subsurface fractures and lithophysal cavities. Elevated values for ratios of {sup 36}Cl to total chloride ({sup 36}Cl/CL) at the level of the proposed repository indicated that small amounts of water carrying bomb-pulse {sup 36}Cl (i.e., {sup 36}Cl/Cl ratios greater than 1250 x 10{sup -15} resulting from {sup 36}Cl produced by atmospheric testing of nuclear devices during the 1950s and early 1960s) had percolated through welded and nonwelded tuffs to depths of 200 to 300 meters (m) beneath the land surface over the past 50 years. Because of the implications of short travel times to the performance of the proposed repository, the U.S. Department of Energy (DOE)/Office of Civilian Radioactive Waste Management (OCRWM), Office of Repository Development (ORD), decided to verify the {sup 36}Cl/Cl data with an independent validation study. DOE asked the USGS

  13. Ash Redistribution Following a Potential Volcanic Eruption at Yucca Mountain

    NASA Astrophysics Data System (ADS)

    Pelletier, J. D.; Delong, S. B.; Cline, M. L.; Harrington, C. D.; Keating, G.

    2005-12-01

    The redistribution of contaminated tephra by hillslope, fluvial, and pedologic processes is a poorly-constrained but important aspect of evaluating the radiological dose from an unlikely volcanic eruption at Yucca Mountain (YM). To better evaluate this hazard, we developed a spatially-distributed numerical model of tephra redistribution that integrates contaminated tephra from hill slopes and active channels, mixes it with clean sediment in the channel system, distributes it on the fan, and migrates it into the soil column. The model is coupled with an atmospheric dispersion model that predicts the deposition of radioactive waste-contaminated tephra at specified grid points. The redistribution model begins in the upper Fortymile Wash drainage basin where it integrates the tephra deposited on steep slopes and active channel beds within a spatially-distributed framework. The Fortymile Wash drainage basin is the focus of this model because tephra from only this basin reaches the Fortymile Wash alluvial fan by fluvial processes, and it is on this fan where the radiological dose to a hypothetical individual is compared to the regulatory standard (via additional biosphere models). The dilution effect of flood scour, mixing, and re-deposition within the upper basin is modeled using a dilution-mixing model widely used in the contaminant-transport literature. The accuracy of this model is established by comparing the model prediction with tephra concentrations measured in channels draining the Lathrop Wells volcanic center. The model combines the contaminated tephra transported from the upper basin with the tephra deposited directly on the fan as primary fallout. On the Fortymile Wash fan, channels and interchannel-divide areas are divided on the basis of soil-geomorphic mapping according to whether they are Holocene or Pleistocene in age. This approach allows the model to incorporate the effects of channel migration on the fan within the past 10,000 yr. The model treats

  14. Thrust faults of southern Diamond Mountains, central Nevada: Implications for hydrocarbons in Diamond Valley and at Yucca Mountain

    SciTech Connect

    French, D.E.

    1993-04-01

    Overmature Mississippian hydrocarbon source rocks in the southern Diamond Mountains have been interpreted to be a klippe overlying less mature source rocks and represented as an analogy to similar conditions near Yucca Mountain (Chamberlain, 1991). Geologic evidence indicates an alternative interpretation. Paleogeologic mapping indicates the presence of a thrust fault, referred to here as the Moritz Nager Thrust Fault, with Devonian rocks emplaced over Permian to Mississippian strata folded into an upright to overturned syncline, and that the overmature rocks of the Diamond Mountains are in the footwall of this thrust. The upper plate has been eroded from most of the Diamond Mountains but remnants are present at the head of Moritz Nager Canyon and at Sentinel Mountain. Devonian rocks of the upper plate comprised the earliest landslide megabreccia. Later, megabreccias of Pennsylvanian and Permian rocks of the overturned syncline of the lower plate were deposited. By this interpretation the maturity of lower-plate source rocks in the southern Diamond Mountains, which have been increased by tectonic burial, is not indicative of conditions in Diamond Valley, adjacent to the west, where upper-plate source rocks might be present in generating conditions. The interpretation that overmature source rocks of the Diamond Mountains are in a lower plate rather than in a klippe means that this area is an inappropriate model for the Eleana Range near Yucca Mountain.

  15. Seismicity in the Vicinity of Yucca Mountain, Nevada, for the Period October 1, 2004 to September 30, 2006

    SciTech Connect

    Smith, Ken

    2007-11-26

    This report describes earthquake activity within approximately 65 km of Yucca Mountain site during the October 1, 2004 to September 30, 2006 time period (FY05-06). The FY05-06 earthquake activity will be compared with the historical and more recent period of seismic activity in the Yucca Mountain region. The relationship between the distribution of seismicity and active faults, historical patterns of activity, and rates of earthquakes (number of events and their magnitudes) are important components in the assessment of the seismic hazard for the Yucca Mountain site. Since October 1992 the University of Nevada has compiled a catalog of earthquakes in the Yucca Mountain area. Seismicity reports have identified notable earthquake activity, provided interpretations of the seismotectonics of the region, and documented changes in the character of earthquake activity based on nearly 30 years of site-characterization monitoring. Data from stations in the seismic network in the vicinity of Yucca Mountain is collected and managed at the Nevada Seismological Laboratory (NSL) at the University of Nevada Reno (UNR). Earthquake events are systematically identified and cataloged under Implementing Procedures developed in compliance with the Nevada System of Higher Education (NSHE) Quality Assurance Program. The earthquake catalog for FY05-06 in the Yucca Mountain region submitted to the Yucca Mountain Technical Data Management System (TDMS) forms the basis of this report.

  16. Environmental assessment: Yucca Mountain site, Nevada research and development area, Nevada; Volume 1

    SciTech Connect

    1986-05-01

    In February 1983, the US Department of Energy (DOE) identified the Yucca Mountain site in Nevada as one of nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high- level radioactive waste. The site is in the Great Basin, which is one of five distinct geohydrologic settings considered for the first repository. To determine their suitability, the Yucca Mountain site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE`s General Guideline for the Recommendation of Sites for the Nuclear Waste Repositories. These evaluations were reported in draft environmental assessments (EA), which were issued for public review and comment. After considering the comments received on the draft EAs, the DOE prepared the final EAs. On the basis of the evaluations reported in this EA, the DOE found that the Yucca Mountain site is not disqualified under the guidelines. The DOE has also found that it is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is nominating the Yucca Mountain site as of five sites suitable for characterization.

  17. Modeling Temporal-Spatial Earthquake and Volcano Clustering at Yucca Mountain, Nevada

    SciTech Connect

    T. Parsons; G.A. Thompson; A.H. Cogbill

    2006-05-31

    The proposed national high-level nuclear repository at Yucca Mountain is close to Quaternary faults and cinder cones. The frequency of these events is low, with indications of spatial and temporal clustering, making probabilistic assessments difficult. In an effort to identify the most likely intrusion sites, we based a 3D finite element model on the expectation that faulting and basalt intrusions are primarily sensitive to the magnitude and orientation of the least principal stress in extensional terranes. We found that in the absence of fault slip, variation in overburden pressure caused a stress state that preferentially favored intrusions at Crater Flat. However, when we allowed central Yucca Mountain faults to slip in the model, we found that magmatic clustering was not favored at Crater Flat or in the central Yucca Mountain block. Instead, we calculated that the stress field was most encouraging to intrusions near fault terminations, consistent with the location of the most recent volcanism at Yucca Mountain, the Lathrop Wells cone. We found this linked fault and magmatic system to be mutually reinforcing in the model in that dike inflation favored renewed fault slip.

  18. Environmental assessment: Yucca Mountain Site, Nevada Research and Development Area, Nevada; Volume 2

    SciTech Connect

    1986-05-01

    In February 1983, the US Department of Energy (DOE) identified the Yucca Mountain site in Nevada as one of nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. The site is in the Great Basin, which is one of five distinct geohydrologic settings considered for the first repository. To determine their suitability, the Yucca Mountain site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE`s General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. These evaluations were reported in draft environmental assessments (EAs), which were issued for public review and comment. After considering the comments received on the draft EAs, the DOE prepared the final EAs. On the basis of the evaluations reported in this EA, the DOE has found that the Yucca Mountain site is not disqualified under the guidelines. The DOE has also found that is is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is nominating the Yucca Mountain site as one of five sites suitable for characterization.

  19. Viability Assessment of a Repository at Yucca Mountain. Volume 1: Introduction and Site Characteristics

    SciTech Connect

    1998-12-01

    This first volume contains an introduction to the viability assessment, including the purpose, scope, waste forms, technical challenges, an historical perspective, regulatory framework, management of the repository, technical components, preparations for the license application, and repository milestones after the assessment. The second part of this first volume addresses characteristics of the Yucca Mountain site.

  20. Earthquake and volcano clustering via stress transfer at Yucca Mountain, Nevada

    USGS Publications Warehouse

    Parsons, T.; Thompson, G.A.; Cogbill, A.H.

    2006-01-01

    The proposed national high-level nuclear waste repository at Yucca Mountain is close to Quaternary cinder cones and faults with Quaternary slip. Volcano eruption and earthquake frequencies are low, with indications of spatial and temporal clustering, making probabilistic assessments difficult. In an effort to identify the most likely intrusion sites, we based a three-dimensional finite-element model on the expectation that faulting and basalt intrusions are sensitive to the magnitude and orientation of the least principal stress in extensional terranes. We found that in the absence of fault slip, variation in overburden pressure caused a stress state that preferentially favored intrusions at Crater Flat. However, when we allowed central Yucca Mountain faults to slip in the model, we found that magmatic clustering was not favored at Crater Flat or in the central Yucca Mountain block. Instead, we calculated that the stress field was most encouraging to intrusions near fault terminations, consistent with the location of the most recent volcanism at Yucca Mountain, the Lathrop Wells cone. We found this linked fault and magmatic system to be mutually reinforcing in the model in that Lathrop Wells feeder dike inflation favored renewed fault slip. ?? 2006 Geological Society of America.

  1. Environmental assessment: Yucca Mountain site, Nevada research and development area, Nevada; Volume 3

    SciTech Connect

    1986-05-01

    In February 1983, the US Department of Energy (DOE) identified the Yucca Mountain site in Nevada as one of nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. The site is in the Great Basin, which is one of five distinct geohydrologic settings considered for the first repository. To determine their suitability, the Yucca Mountain site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE`s General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. These evaluations were reported in draft environmental assessments (EAs), which were issued for public review and comment. After considering the comments received on the draft EAs, the DOE prepared the final EAs. On the basis of the evaluations reported in this EA, the DOE has found that the Yucca Mountain site is not disqualified under the guidelines. The DOE has also found that it is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is nominating the Yucca Mountain site as one of five sites suitable for characterization.

  2. Los Alamos National Laboratory Yucca Mountain Site Characterization Project 1995 quality program status report

    SciTech Connect

    Bolivar, S.L.

    1996-07-01

    This status report summarizes the activities and accomplishments of the Los Alamos National Laboratory Yucca Mountain Site Characterization Project`s (YMP`s) quality assurance program for January 1 to September 30, 1995. The report includes major sections on program activities and trend analysis.

  3. Two-phase unsaturated flow at Yucca Mountain, Nevada: A report on current understanding

    NASA Astrophysics Data System (ADS)

    Pruess, Karsten

    Thick unsaturated zones in semi-arid regions have some unique attributes that are favorable for long-term isolation of hazardous wastes. The disposal concept at Yucca Mountain takes advantage of low ambient water fluxes. Evaluation of site suitability must be based on an understanding of two-phase (liquid-gas) fluid flow and heat transfer processes in a heterogeneous, fractured rock mass. A large body of relevant knowledge has been accumulated in various fields, including petroleum and geothermal reservoir engineering, chemical engineering, civil engineering, and soil science. Complications at Yucca Mountain arise from the partly episodic and localized nature of water seepage in fracture networks. This limits the applicability of spatial and temporal averaging, and poses great challenges for numerical modeling. Significant flow and heat transfer effects may occur in the gas phase. Observations of natural and man-made chemical tracers as well as controlled field experiments have provided much useful information on mass transport at Yucca Mountain, including the occurrence of fast preferential flow. It is now clear that fracture-matrix interactions are considerably weaker than would be expected from a concept of water flowing in fractures as areally extensive sheets. The Yucca Mountain system is expected to be quite robust in coping with larger seepage rates, as may occur under future more pluvial climatic conditions.

  4. DOE`s Yucca Mountain studies: What are they? Why are they being done?

    SciTech Connect

    1990-12-01

    This booklet is about the disposal of high-level nuclear waste in the United States. It is intended for readers who do not have a technical background. It discusses why scientists and engineers think high-level nuclear waste may be disposed of safely underground. It also describes why Yucca Mountain, Nevada, is being studied and provides basic information about those studies.

  5. ENVIRONMENTAL ASSESSMENT OVERVIEW YUCCA MOUNTAIN SITE, NEVADA RESEARCH AND DEVELOPMENT AREA, NEVADA

    SciTech Connect

    DOE

    1986-05-01

    In February 1983, the U.S. Department of Energy (DOE) identified the Yucca Mountain site in Nevada as one of nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. The site is in the Great Basin, which is one of five distinct geohydrologic settings considered for the first repository. To determine their suitability, the Yucca Mountain site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. These evaluations were reported in draft environmental assessments (EAs), which were issued for public review and comment. After considering the comments received on the draft EAs, the DOE prepared the final EAs. On the basis of the evaluations reported in this EA, the DOE has found that the Yucca Mountain site is not disqualified under the guidelines. The DOE has also found that it is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is nominating the Yucca Mountain site as one of five sites suitable for characterization.

  6. A preliminary characterization of the spatial variability of precipitation at Yucca Mountain, Nevada

    SciTech Connect

    Hevesi, J.A.; Flint, A.L.; Ambos, D.S.

    1994-12-31

    Isohyetal maps of precipitation and numerical models for simulating precipitation are needed to characterize natural infiltration at Yucca Mountain, Nevada. The objective of this study was to characterize the spatial variability of precipitation within the domain of the natural catchments overlying the potential repository, and to define preliminary geostatistical models based on differences in storm type for the numerical simulation of precipitation.

  7. Yucca Mountain Biological Resources Monitoring Program. Progress report, January 1994--December 1994

    SciTech Connect

    1995-07-01

    The US Department of Energy (DOE) is required by the Nuclear Waste Policy Act of 1982 (as amended in 1987) to study and characterize the suitability of Yucca Mountain as a potential geological repository for high-level nuclear waste. During site characterization, the DOE will conduct a variety of geotechnical, geochemical, geological, and hydrological studies to determine the suitability of Yucca Mountain as a potential repository. To ensure that site characterization activities do not adversely affect the environment at Yucca Mountain, a program has been implemented to monitor and mitigate potential impacts and ensure activities comply with applicable environmental regulations. This report describes the activities and accomplishments of EG and G Energy Measurements, Inc. (EG and G/EM) from January 1994 through December 1994 for six program areas within the Terrestrial Ecosystem component of the environmental program for the Yucca Mountain Site Characterization Project (YMP): Site Characterization Effects, Desert Tortoises (Gopherus agassizii), Habitat Reclamation, Monitoring and Mitigation, Radiological Monitoring, and Biological Support.

  8. Equilibrium modeling of the formation of zeolites in fractures at Yucca Mountain, Nevada

    SciTech Connect

    Chipera, S.J.; Bish, D.L.; Carlos, B.A.

    1993-08-01

    Yucca Mountain, in southern Nevada, is currently being investigated to determine its suitability to host the first US high-level nuclear waste repository. One of the reasons that Yucca Mountain was chosen for study is the presence of thick sequences of zeolite-rich horizons. In as much as fractures may serve as potential pathways for aqueous transport, the minerals that line fractures are of particular interest. Zeolites are common in fractures at Yucca Mountain and consist mainly of clinoptilolite/heulandite and mordenite although sporadic occurrences of chabazite, erionite, phillipsite, and stellrite have been identified using X-ray powder diffraction. To understand better the conditions under which the observed zeolite species were formed, thermodynamic data were estimated and calculations of log a((K{sup +}){sup 2}/Ca{sup ++}) versus log a((Na{sup +}){sup 2}/Ca{sup ++}) were conducted at various temperatures and silica activities. Using present-day Yucca Mountain water chemistries as a lower constraint on silica activity, clinoptilolite/heulandite and mordenite are still the zeolite species that would form under present conditions.

  9. Potential contaminant transport in the regional Carbonate Aquifer beneath Yucca Mountain, Nevada, USA

    NASA Astrophysics Data System (ADS)

    Bredehoeft, John; King, Michael

    2010-05-01

    Yucca Mountain, Nevada is the site of the proposed US geologic repository for spent nuclear fuel and high-level radioactive waste. The repository is to be a mine, sited approximately 300 m below the crest of the mountain, in a sequence of variably welded and fractured mid-Miocene rhylolite tuffs, in the unsaturated zone, approximately 300 m above the water table. Beneath the proposed repository, at a depth of 2 km, is a thick sequence of Paleozoic carbonate rocks that contain the highly transmissive Lower Carbonate Aquifer. In the area of Yucca Mountain the Carbonate Aquifer integrates groundwater flow from north of the mountain, through the Amargosa Valley, through the Funeral Mountains to Furnace Creek in Death Valley, California where the groundwater discharges in a set of large springs. Data that describe the Carbonate Aquifer suggest a concept for flow through the aquifer, and based upon the conceptual model, a one-layer numerical model was constructed to simulate groundwater flow in the Carbonate Aquifer. Advective transport analyses suggest that the predicted travel time of a particle from Yucca Mountain to Death Valley through the Carbonate Aquifer might be as short as 100 years to as long 2,000 years, depending upon the porosity.

  10. Regulatory compliance for a Yucca Mountain Repository: A performance assessment perspective

    SciTech Connect

    Dyer, J.R.; Van Luik, A.E.; Gil, A.V.; Brocoum, S.J.

    1997-02-01

    The U.S. Department of Energy`s Yucca Mountain Site Characterization Project is scheduled to submit a License Application in the year 2002. The License Application is to show compliance with the regulations promulgated by the U.S. Nuclear Regulatory Commission which implement standards promulgated by the U.S. Environmental Protection Agency. These standards are being revised, and it is not certain what their exact nature will be in term of either the performance measure(s) or the time frames that are to be addressed. This paper provides some insights pertaining to this regulatory history, an update on Yucca Mountain performance assessments, and a Yucca Mountain Site Characterization Project perspective on proper standards based on Project experience in performance assessment for its proposed Yucca Mountain Repository system. The Project`s performance assessment based perspective on a proper standard applicable to Yucca Mountain may be summarized as follows: a proper standard should be straight forward and understandable; should be consistent with other standards and regulations; and should require a degree of proof that is scientifically supportable in a licensing setting. A proper standard should have several attributes: (1) propose a reasonable risk level as its basis, whatever the quantitative performance measure is chosen to be, (2) state a definite regulatory time frame for showing compliance with quantitative requirements, (3) explicitly recognize that the compliance calculations are not predictions of actual future risks, (4) define the biosphere to which risk needs to be calculated in such a way as to constrain potentially endless speculation about future societies and future human actions, and (5) have as its only quantitative requirement the risk limit (or surrogate performance measure keyed to risk) for the total system.

  11. Site characterization progress report: Yucca Mountain, Nevada, April 1, 1992--September 30, 1992, Number 7

    SciTech Connect

    1992-12-01

    In accordance with section 113(b)(3) of the Nuclear Waste Policy Act of 1982, as amended (NWPA), the Department has prepared the seventh in a series of reports on the progress of site characterization at the Yucca Mountain candidate site. The Civilian Radioactive Waste Management Program made significant progress during the reporting period at the Yucca Mountain Site Characterization Project. Several important advances were made in the surface-based testing program including: initiation of borehole drilling utilizing the new, state-of-the-art LM-300 drill rig which employs dry drilling and coring techniques; neutron access borehole drilling to evaluate infiltration processes; excavations to aid geologic mapping; and trenching in Midway Valley to study Quaternary faulting. A Floodplain Assessment and Statement of Findings was published in the Federal Register which concluded there would be no significant impact nor cumulative impacts on floodplains resulting from Exploratory Studies Facility activities. The National Academy of Sciences` National Research Council released its report entitled ``Ground Water at Yucca Mountain: How High Can It Rise?`` which concluded that none of the evidence cited as proof of groundwater upwelling in and around Yucca Mountain could be reasonably attributed to that process and that significant water table excursions to the repository design level are not shown by the geologic record. The June 29, 1992, earthquake near Yucca Mountain provided scientists with a wealth of information relevant to understanding the neotectonics of the area and the geometry of faults at depth. Early findings suggest that accelerations recorded were well within proposed design limits for the surface waste handling facilities.

  12. Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada

    SciTech Connect

    K. Coppersmith; R. Quittmeyer

    2005-02-16

    This report describes a scientific analysis to bound credible horizontal peak ground velocities (PGV) for the repository waste emplacement level at Yucca Mountain. Results are presented as a probability distribution for horizontal PGV to represent uncertainties in the analysis. The analysis also combines the bound to horizontal PGV with results of ground motion site-response modeling (BSC 2004 [DIRS 170027]) to develop a composite hazard curve for horizontal PGV at the waste emplacement level. This result provides input to an abstraction of seismic consequences (BSC 2004 [DIRS 169183]). The seismic consequence abstraction, in turn, defines the input data and computational algorithms for the seismic scenario class of the total system performance assessment (TSPA). Planning for the analysis is documented in Technical Work Plan TWP-MGR-GS-000001 (BSC 2004 [DIRS 171850]). The bound on horizontal PGV at the repository waste emplacement level developed in this analysis complements ground motions developed on the basis of PSHA results. In the PSHA, ground motion experts characterized the epistemic uncertainty and aleatory variability in their ground motion interpretations. To characterize the aleatory variability they used unbounded lognormal distributions. As a consequence of these characterizations, as seismic hazard calculations are extended to lower and lower annual frequencies of being exceeded, the ground motion level increases without bound, eventually reaching levels that are not credible (Corradini 2003 [DIRS 171191]). To provide credible seismic inputs for TSPA, in accordance with 10 Code of Federal Regulations (CFR) 63.102(j) [DIRS 156605], this complementary analysis is carried out to determine reasonable bounding values of horizontal PGV at the waste emplacement level for annual frequencies of exceedance as low as 10{sup -8}. For each realization of the TSPA seismic scenario, the results of this analysis provide a constraint on the values sampled from the

  13. Science and students; Yucca Mountain Project`s educational outreach and public tour programs

    SciTech Connect

    Gil, A.V.; Larkin, E.L.; Harle, E.

    1992-11-01

    Decisions regarding the use of energy, technology, and the environment require a well-educated and science-literate public. This paper reports that one of these decisions involves the problem of nuclear waste disposal. Many Nevadans are uninformed or misinformed about the Yucca Mountain Site Characterization Project (YMP). Mountain Site Characterization Project (YMP). The U.S. Department of Energy (DOE) has an active public outreach program in place that includes educational presentations for schools and a tour program for the public. Results of surveys taken after the tours to Yucca Mountain indicate that participants have learned about the site and the characterization program. In many cases, negative opinions about the YMP have changed.

  14. Simulating the Thermal History of the Unsaturated Zone at Yucca Mountain, Nevada

    SciTech Connect

    B.D. Marshal; J.F. Whelan

    2001-07-23

    Heat transfer within Earth's upper crust is primarily by conduction, and conductive thermal models adequately explain the cooling history of deep, batholith-scale intrusions and surrounding wall rocks, as confirmed by numerous thermochronometric studies. However, caldera magmatic systems require consideration of the small and localized component of hydrothermal convection and numerical models to simulate additional boundary conditions, irregular magma chamber shapes, and complex intrusive histories. At Yucca Mountain, Nevada, the site of a potential high-level nuclear waste repository, simulating the detailed thermal history at any location in the unsaturated zone requires knowledge of the shape of the magma chamber and its proximity to Yucca Mountain (the southern margin of the Timber Mountain caldera complex is approximately 8 km north of the potential repository site), the temporal and spatial extent of hydrothermal convection, the erosional history of the area, and past levels of the water table.

  15. Approach to developing a ground-motion design basis for facilities important to safety at Yucca Mountain

    SciTech Connect

    King, J.L.

    1990-04-01

    The Department of Energy has proposed a methodology for developing a ground-motion design basis for prospective facilities at Yucca Mountain that are important to safety. The methodology utilizes a quasi-deterministic construct that is designed to provide a conservative, robust, and reproducible estimate of ground motion that has a one-in-ten chance of occurring during the preclosure period. This estimate is intended to define a ground-motion level for which the seismic design would ensure minimal disruption to operations; engineering analyses to ensure safe performance in the unlikely event that the design basis is exceeded are a part of the proposed methodology. 8 refs.

  16. Characterization and prediction of subsurface pneumatic response at Yucca Mountain, Nevada

    NASA Astrophysics Data System (ADS)

    Ahlers, C. Fredrik; Finsterle, Stefan; Bodvarsson, Gudmundur S.

    1999-05-01

    Yucca Mountain, Nevada is being investigated as the proposed site for geologic disposal of the United States' high level nuclear waste. A massive effort to collect data for characterization of the thermo-hydrologic behavior of the unsaturated zone is being conducted at the site. Several boreholes have been instrumented by the United States Geological Survey and the Nye County Nuclear Waste Repository Project Office for passive pneumatic monitoring of the subsurface. One-, two- and three-dimensional numerical models are used to simulate the observed subsurface pressure variations. The data are inverted using these models in order to characterize the unsaturated system and estimate the pneumatic diffusivity of important geologic features. Blind predictions of subsurface response and subsequent comparison to recorded data have built confidence in the models of Yucca Mountain. Inversions show that the pneumatic response of the system is dominated by the Paintbrush non-welded unit (PTn). Faults are shown to be fast pathways for gas flow but affect subsurface response only on a relatively local scale. Estimates of the diffusivity of the tuffs that comprise Yucca Mountain range from a low of 0.008 m 2/s in the non-welded pre-Yucca bedded tuff layer to a high of 4 m 2/s in the densely welded, fractured Topopah Spring tuff. Estimates of diffusivity in fault zones at Yucca Mountain range between 0.03 m 2/s and 1500 m 2/s with the highest being in the Drill Hole Wash fault where it intersects the Topopah Spring tuff.

  17. TECHNICAL PEER REVIEW REPORT - YUCCA MOUNTAIN: WASTE PACKAGE CLOSURE CONTROL SYSTEM

    SciTech Connect

    NA

    2005-10-25

    The objective of the Waste Package Closure System (WPCS) project is to assist in the disposal of spent nuclear fuel (SNF) and associated high-level wastes (HLW) at the Yucca Mountain site in Nevada. Materials will be transferred from the casks into a waste package (WP), sealed, and placed into the underground facility. The SNF/HLW transfer and closure operations will be performed in an aboveground facility. The objective of the Control System is to bring together major components of the entire WPCS ensuring that unit operations correctly receive, and respond to, commands and requests for data. Integrated control systems will be provided to ensure that all operations can be performed remotely. Maintenance on equipment may be done using hands-on or remote methods, depending on complexity, exposure, and ease of access. Operating parameters and nondestructive examination results will be collected and stored as permanent electronic records. Minor weld repairs must be performed within the closure cell if the welds do not meet the inspection acceptance requirements. Any WP with extensive weld defects that require lids to be removed will be moved to the remediation facility for repair.

  18. SYSTHESIS OF VOLCANISM STUDIES FOR THE YUCCA MOUNTAIN SITE CHARACTERIZATION PROJECT

    SciTech Connect

    Perry, F. V.; Crowe, G. A.; Valentine, G. A.; Bowker, L. M.

    1997-09-23

    This report synthesizes the results of volcanism studies conducted by scientists at the Los Alamos National Laboratory and collaborating institutions on behalf of the Department of Energy's Yucca Mountain Project. Chapter 1 introduces the volcanism issue for the Yucca Mountain site and provides the reader with an overview of the organization, content, and significant conclusions of this report. The hazard of future basaltic volcanism is the primary topic of concern including both events that intersect a potential repository and events that occur near or within the waste isolation system of a repository. Future volcanic events cannot be predicted with certainty but instead are estimated using formal methods of probabilistic volcanic hazard assessment (PVHA). Chapter 2 describes the volcanic history of the Yucca Mountain region (YMR) and emphasizes the Pliocene and Quaternary volcanic record, the interval of primary concern for volcanic risk assessment. The distribution, eruptive history, and geochronology of Plio-Quaternary basalt centers are described by individual center emphasizing the younger postcaldera basalt (<5 Ma). The Lathrop Wells volcanic center is described in detail because it is the youngest basalt center in the YMR. The age of the Lathrop Wells center is now confidently determined to be about 75 thousand years old. Chapter 3 describes the tectonic setting of the YMR and presents and assesses the significance of multiple alternative tectonic models. The distribution of Pliocene and Quaternary basaltic volcanic centers is evaluated with respect to tectonic models for detachment, caldera, regional and local rifting, and the Walker Lane structural zone. Geophysical data are described for the YMR and are used as an aid to understand the distribution of past basaltic volcanic centers and possible future magmatic processes. Chapter 4 discusses the petrologic and geochemical features of basaltic volcanism in the YMR, the southern Great Basin and the Basin

  19. Water levels in periodically measured wells in the Yucca Mountain area, Nye County, Nevada, 1981-87

    USGS Publications Warehouse

    Robison, J.H.; Stephens, D.M.; Luckey, R.R.; Baldwin, D.A.

    1988-01-01

    This report contains data on groundwater levels beneath Yucca Mountain and adjacent areas, Nye County, Nevada. In addition to new data collected since 1983, the report contains data that has been updated from previous reports, including added explanations of the data. The data was collected in cooperation with the U.S. Department of Energy to help that agency evaluate the suitability of the area of storing high-level nuclear waste. The water table in the Yucca Mountain area occurs in ash-flow and air-fall tuff of Tertiary age. West of the crest of Yucca Mountain, water level altitudes are about 775 m above sea level. Along the eastern edge and southern end of Yucca Mountain, the potentiometric surface generally is nearly flat, ranging from about 730 to 728 m above sea level. (USGS)

  20. Aspects of igneous activity significant to a repository at Yucca Mountain, Nevada

    SciTech Connect

    Krier, D. J.; Perry, F. V.

    2004-01-01

    Location, timing, volume, and eruptive style of post-Miocene volcanoes have defined the volcanic hazard significant to a proposed high-level radioactive waste (HLW) and spent nuclear fuel (SNF) repository at Yucca Mountain, Nevada, as a low-probability, high-consequence event. Examination of eruptive centers in the region that may be analogueues to possible future volcanic activity at Yucca Mountain have aided in defining and evaluating the consequence scenarios for intrusion into and eruption above a repository. The probability of a future event intersecting a repository at Yucca Mountain has a mean value of 1.7 x 10{sup -8} per year. This probability comes from the Probabilistic Volcanic Hazard Assessment (PVHA) completed in 1996 and updated to reflect change in repository layout. Since that time, magnetic anomalies representing potential buried volcanic centers have been identified fiom magnetic surveys; however these potential buried centers only slightly increase the probability of an event intersecting the repository. The proposed repository will be located in its central portion of Yucca Mountain at approximately 300m depth. The process for assessing performance of a repository at Yucca Mountain has identified two scenarios for igneous activity that, although having a very low probability of occurrence, could have a significant consequence should an igneous event occur. Either a dike swarm intersecting repository drifts containing waste packages, or a volcanic eruption through the repository could result in release of radioactive material to the accessible environment. Ongoing investigations are assessing the mechanisms and significance of the consequence scenarios. Lathrop Wells Cone ({approx}80,000 yrs), a key analogue for estimating potential future volcanic activity, is the youngest surface expression of apparent waning basaltic volcanism in the region. Cone internal structure, lavas, and ash-fall tephra have been examined to estimate eruptive volume

  1. Uranium-series dating of secondary carbonates near Yucca Mountain, Nevada. Applications to tectonic, paleoclimatic, and paleohydrologic problems

    USGS Publications Warehouse

    Muhs, D.R.; Whitney, J.W.; Shroba, R.R.; Taylor, E.M.; Bush, C.A.

    1990-01-01

    Near-surface accumulations of secondary carbonates are common in the soils and sediments of the Yucca Mountain area. These carbonates contain small amounts of uranium that allow dating by the uranium-series disequilibrium method. Preliminary results from the Yucca Mountain area indicate that the U-series methods can (1) identify multiple episodes of tectonic fracturing, (2) provide a chronologic framework for paleoclimatically significant eolian deposits, and (3) place constraints on the probable source of waters from which the carbonates precipitated.

  2. The Effects of Site Characterization Activities on the Abundance of Ravens (Corvus corax) in the Yucca Mountain Area

    SciTech Connect

    P.E. Lederle

    1998-05-08

    In response to the Nuclear Waste Policy Act of 1982 and the Nuclear Waste Policy Amendments Act of 1987, the U.S. Department of Energy (DOE) developed and is implementing the Yucca Mountain Site Characterization Project. Raven abundance was measured from August 1991 through August 1995 along treatment and control routes to evaluate whether site characterization activities resulted in increased raven abundance at Yucca Mountain. This study fulfills the requirement set forth in the incidental take provisions of the Biological Opinion that DOE monitor the abundance of ravens at Yucca Mountain. Ravens were more abundant at Yucca Mountain than in the control area, and raven abundance in both areas increased over time. However, the magnitude of differences between Yucca Mountain and control surveys did not change over time, indicating that the increase in raven abundance observed during this study was not related to site characterization activities. Increases over time on both Yucca Mountain and control routes are consistent with increases in raven abundance in the Mojave Desert reported by the annual Breeding Bird Survey of the US. Fish and Wildlife Service. Evidence from the Desert Tortoise Monitoring Program at Yucca Mountain suggests that ravens are not a significant predator of small tortoises in this locale. Carcasses of small tortoises (less than 110 mm in length) collected during the study showed little evidence of raven predation, and 59 radiomarked hatchlings that were monitored on a regular basis were not preyed upon by ravens. Overall, no direct evidence of raven predation on tortoises was observed during this study. Small tortoises are probably encountered so infrequently by ravens that they are rarely exploited as a food source. This is likely due to the relatively low abundance of both desert tortoises and ravens in the Yucca Mountain area.

  3. A revised Litostragraphic Framework for the Southern Yucca Mountain Area, Nye County, Nevada

    SciTech Connect

    R.W. Spengler; F.M. Byers; R.P. Dickerson

    2006-03-24

    An informal, revised lithostratigraphic framework for the southern Yucca Mountain area, Nevada has been developed to accommodate new information derived from subsurface investigations of the Nye County Early Warning Drilling Program. Lithologies penetrated by recently drilled boreholes at locations between Stagecoach Road and Highway 95 in southern Nye County include Quaternary and Pliocene alluvium and alluvial breccia, Miocene pyroclastic flow deposits and intercalated lacustrine siltstone and claystone sequences, early Miocene to Oligocene pre-volcanic sedimentary rocks, and Paleozoic strata. Of the 37 boreholes currently drilled, 21 boreholes have sufficient depth, spatial distribution, or traceable pyroclastic flow, pyroclastic fall, and reworked tuff deposits to aid in the lateral correlation of lithostrata. Medial and distal parts of regional pyroclastic flow deposits of Miocene age can be correlated with the Timber Mountain, Paintbrush, Crater Flat, and Tram Ridge Groups. Rocks intercalated between these regional pyroclastic flow deposits are substantially thicker than in the central part of Yucca Mountain, particularly near the downthrown side of major faults and along the southern extent of exposures at Yucca Mountain.

  4. A revised lithostratigraphic framework for the southern Yucca Mountain area, Nye County, Nevada

    USGS Publications Warehouse

    Spengler, R.W.; Byers, F.M.; Dickerson, R.P.

    2006-01-01

    An informal, revised lithostratigraphic framework for the southern Yucca Mountain area, Nevada has been developed to accommodate new information derived from subsurface investigations of the Nye County Early Warning Drilling Program. Lithologies penetrated by recently drilled boreholes at locations between Stagecoach Road and Highway 95 in southern Nye County include Quaternary and Pliocene alluvium and alluvial breccia, Miocene pyroclastic flow deposits, Miocene intercalated lacustrine siltstone and claystone sequences, early Miocene to Oligocene pre-volcanic sedimentary rocks, and Paleozoic strata. Of the 37 boreholes currently drilled, 21 boreholes have sufficient depth, spatial distribution, or traceable pyroclastic flow, pyroclastic fall, and reworked tuff deposits to aid in the lateral correlation of lithostrata. Medial and distal parts of regional pyroclastic flow deposits of Miocene age can be correlated with the Timber Mountain, Paintbrush, Crater Flat, and Tram Ridge Groups. Rocks intercalated between these regional pyroclastic flow deposits are substantially thicker than in the central part of Yucca Mountain, particularly near the downthrown side of major faults and along the southern extent of exposures at Yucca Mountain.

  5. Distribution and chemistry of fracture-lining minerals at Yucca Mountain, Nevada

    SciTech Connect

    Carlos, B.A.; Chipera, S.J.; Bish, D.L.

    1995-12-01

    Yucca Mountain, a >1.5-km-thick sequence of tuffs and subordinate lavas in southwest Nevada, is being investigated as a potential high-level nuclear waste repository site. Fracture-lining minerals have been studied because they may provide information on past fluid transport and because they may act as natural barriers to radionuclide migration within the fractures. Cores from seven drill holes have been studied to determine the distribution and chemistry of minerals lining fractures at Yucca Mountain. Fracture-lining minerals in tuffs of the Paintbrush Group, which is above the static water level at Yucca Mountain, are highly variable in distribution, both vertically and laterally across the mountain, with the zeolites mordenite, heulandite, and stellerite widespread in fractures even though the tuff matrix is generally devitrified and nonzeolitic. Where heulandite occurs as both tabular and prismatic crystals in the same fracture, the two morphologies have different compositions, suggesting multiple episodes of zeolite formation within the fractures. Manganese-oxide minerals within the Paintbrush Group are rancieite and lithiophorite. The silica polymorphs (quartz, tridymite, and cristobalite) generally exist in fractures where they exist in the matrix, suggesting that they formed in the fractures at the same time they formed in the matrix. Fluorite, calcite, and opal occur over tridymite in some lithophysal cavities. Calcite also occurs over zeolites in fractures unrelated to lithophysal cavities and is often the youngest mineral in a given fracture. The clays smectite, palygorskite, and sepiolite are common in fractures in the Paintbrush Group in drill core USW GU-3; smectite is an abundant fracture-coating mineral in all drill cores at Yucca Mountain.

  6. Pre-waste-emplacement ground-water travel time sensitivity and uncertainty analyses for Yucca Mountain, Nevada; Yucca Mountain Site Characterization Project

    SciTech Connect

    Kaplan, P.G.

    1993-01-01

    Yucca Mountain, Nevada is a potential site for a high-level radioactive-waste repository. Uncertainty and sensitivity analyses were performed to estimate critical factors in the performance of the site with respect to a criterion in terms of pre-waste-emplacement ground-water travel time. The degree of failure in the analytical model to meet the criterion is sensitive to the estimate of fracture porosity in the upper welded unit of the problem domain. Fracture porosity is derived from a number of more fundamental measurements including fracture frequency, fracture orientation, and the moisture-retention characteristic inferred for the fracture domain.

  7. Mineralogy, petrology and whole-rock chemistry of selected mechanical test samples of Yucca Mountain tuffs; Yucca Mountain Site Characterization Project

    SciTech Connect

    Connolly, J.R.

    1991-12-01

    Petrologic, bulk chemical and mineralogic data are presented for 19 samples of tuffaceous rocks from core holes UE-25a{number_sign}1, USW G-1, USW GU-3, and USW G-4 at Yucca Mountain, Nevada. The suite of samples contains a wide variety of petrologic types, including zeolitized, glassy, and devitrified tuffs. Data include hand sample and thin section descriptions (with modal analyses for which uncertainties are estimated), and major element analyses with uncertainty estimates. No uncertainties were estimated for qualitative mineral identifications by X-ray diffraction. 5 refs., 1 fig., 4 tabs.

  8. Thermal and mechanical codes first benchmark exercise: Part 1, Thermal analysis; Yucca Mountain Project

    SciTech Connect

    Costin, L.S.; Bauer, S.J.

    1990-06-01

    Thermal and mechanical models for intact and jointed rock mass behavior are being developed, verified, and validated at Sandia National Laboratories for the Yucca Mountain Project. Benchmarking is an essential part of this effort and is the primary tool used to demonstrate verification of engineering software used to solve thermomechanical problems. This report presents the results of the first phase of the first thermomechanical benchmark exercise. In the first phase of this exercise, three finite element codes for nonlinear heat conduction and one coupled thermoelastic boundary element code were used to solve the thermal portion of the benchmark problem. The codes used by the participants in this study were DOT, COYOTE, SPECTROM-41, and HEFF. The problem solved by each code was a two-dimensional idealization of a series of drifts whose dimensions approximate those of the underground layout in the conceptual design of a prospective repository for high-level radioactive waste at Yucca Mountain. 20 refs., 50 figs., 3 tabs.

  9. Estimation of percolation flux from borehole temperature data at Yucca Mountain, Nevada.

    PubMed

    Bodvarsson, G S; Kwicklis, E; Shan, C; Wu, Y S

    2003-01-01

    Temperature data from the unsaturated zone (UZ) at Yucca Mountain are analyzed to estimate percolation-flux rates and overall heat flux. A multilayer, one-dimensional analytical solution is presented for determining percolation flux from temperature data. Case studies have shown that the analytical solution agrees very well with results from the numerical code, TOUGH2. The results of the analysis yield percolation fluxes in the range from 0 to 20 mm/year for most of the deep boreholes. This range is in good agreement with the results of infiltration studies at Yucca Mountain. Percolation flux for the shallower boreholes, however, cannot be accurately determined from temperature data alone because large gas flow in the shallow system alters the temperature profiles. Percolation-flux estimates for boreholes located near or intersecting major faults are significantly higher than those for other boreholes. These estimates may be affected by gas flow in the faults. PMID:12714282

  10. Parallel computing simulation of fluid flow in the unsaturated zone of Yucca Mountain, Nevada.

    PubMed

    Zhang, Keni; Wu, Yu-Shu; Bodvarsson, G S

    2003-01-01

    This paper presents the application of parallel computing techniques to large-scale modeling of fluid flow in the unsaturated zone (UZ) at Yucca Mountain, Nevada. In this study, parallel computing techniques, as implemented into the TOUGH2 code, are applied in large-scale numerical simulations on a distributed-memory parallel computer. The modeling study has been conducted using an over-1-million-cell three-dimensional numerical model, which incorporates a wide variety of field data for the highly heterogeneous fractured formation at Yucca Mountain. The objective of this study is to analyze the impact of various surface infiltration scenarios (under current and possible future climates) on flow through the UZ system, using various hydrogeological conceptual models with refined grids. The results indicate that the 1-million-cell models produce better resolution results and reveal some flow patterns that cannot be obtained using coarse-grid modeling models. PMID:12714301

  11. Multiscale Thermohydrologic Model Supporting the Licence Application for the Yucca Mountain Repository

    SciTech Connect

    T.A> Buscheck; Y. Sun; Y. Hao

    2006-03-28

    The MultiScale ThermoHydrologic Model (MSTHM) predicts thermal-hydrologic (TH) conditions within emplacement tunnels (drifts) and in the adjoining host rock at Yucca Mountain, Nevada, which is the proposed site for a radioactive waste repository in the US. Because these predictions are used in the performance assessment of the Yucca Mountain repository, they must address the influence of variability and uncertainty of the engineered- and natural-system parameters that significantly influence those predictions. Parameter-sensitivity studies show that the MSTHM predictions adequately propagate the influence of parametric variability and uncertainty. Model-validation studies show that the influence of conceptual-model uncertainty on the MSTHM predictions is insignificant compared to that of parametric uncertainty, which is propagated through the MSTHM.

  12. Massively parallel computing simulation of fluid flow in the unsaturated zone of Yucca Mountain, Nevada

    SciTech Connect

    Zhang, Keni; Wu, Yu-Shu; Bodvarsson, G.S.

    2001-08-31

    This paper presents the application of parallel computing techniques to large-scale modeling of fluid flow in the unsaturated zone (UZ) at Yucca Mountain, Nevada. In this study, parallel computing techniques, as implemented into the TOUGH2 code, are applied in large-scale numerical simulations on a distributed-memory parallel computer. The modeling study has been conducted using an over-one-million-cell three-dimensional numerical model, which incorporates a wide variety of field data for the highly heterogeneous fractured formation at Yucca Mountain. The objective of this study is to analyze the impact of various surface infiltration scenarios (under current and possible future climates) on flow through the UZ system, using various hydrogeological conceptual models with refined grids. The results indicate that the one-million-cell models produce better resolution results and reveal some flow patterns that cannot be obtained using coarse-grid modeling models.

  13. CORROSION RELIABILITY PREDICTION: LONG TERM NUCLEAR WASTE STORAGE IN YUCCA MOUNTAIN

    SciTech Connect

    G.S. Frankel; E. Tada; B. Maier

    2005-08-18

    The US. Department of Energy has proposed the disposal of high level nuclear waste from commercial and defense reactors in a mined geologic repository under Yucca Mountain, Nevada. The waste will be stored in metallic canisters. The barrier against corrosion will be an Alloy 22 canister and a Ti Grade 7 drip shield. Both of these materials are extremely corrosion resistant. The environment inside Yucca Mountain is relatively benign, but the long time period over which these materials must resist penetration makes corrosion a concern. This paper presents a background of the corrosion issues and shows some recent results regarding measurements of localized corrosion under thin aqueous layers and layers that simulate wet dust deposits.

  14. Evaluating the Long-Term Safety of a Repository at Yucca Mountain 

    SciTech Connect

    Van Luik, Abe

    2009-07-17

    Regulations require that the repository be evaluated for its health and safety effects for 10,000 years for the Site Recommendation process. Regulations also require potential impacts to be evaluated for up to a million years in an Environmental Impact Statement. The Yucca Mountain Project is in the midst of the Site Recommendation process. The Total System Performance Assessment (TSPA) that supports the Site Recommendation evaluated safety for these required periods of time. Results showed it likely that a repository at this site could meet the licensing requirements promulgated by the Nuclear Regulatory Commission. The TSPA is the tool that integrates the results of many years of scientific investigations with design information to allow evaluations of potential far-future impacts of building a Yucca Mountain repository. Knowledge created in several branches of physics is part of the scientific basis of the TSPA that supports the Site Recommendation process.

  15. Mineralogical Charecteristics of Yucca Mountain Alluvium and Effects on Neptunium (V) Sorption

    SciTech Connect

    M. Ding; S.J. Chipera; P.W. Reimus

    2006-09-05

    Saturated alluvium is expected to serve as an important natural barrier to radionuclide transport at Yucca Mountain, the proposed geological repository for disposal of high-level nuclear wastes. {sup 237}Np(V) (half-life = 2.4 x 10{sup 5} years) has been identified as one of the radionuclides that could potentially contribute the greatest dose to humans because of its relatively high solubility and weak adsorption to volcanic tuffs under oxidizing conditions. The previous studies suggested that the mineralogical characteristics of the alluvium play an important role in the interaction between Np(V) and the alluvium. The purpose of this study is to further evaluate the mineralogical basis for Neptunium (V) sorption by saturated alluvium located down-gradient of Yucca Mountain.

  16. Site characterization progress report, Yucca Mountain, Nevada: Number 19, April 1, 1998--September 30, 1998

    SciTech Connect

    1999-06-01

    The nineteenth semiannual report of the Yucca Mountain Site Characterization Project (YMP) summarizes activities during the period from April 1, 1998, through September 30, 1998. Project activities are aimed at evaluating Yucca Mountain as a potential location for permanent geologic disposal of nuclear materials, as directed by the Nuclear Waste Policy Act of 1982, as amended (NWPA). The progress report documents activities this period that contribute to completing the Project`s near-term programmatic and statutory objectives. These objectives include completing the Viability Assessment, the Environmental Impact Statement (EIS), a possible US Department of Energy (DOE) Secretarial Site Recommendation to the President, and, if the site is suitable, submittal of a license application to the US Nuclear Regulatory Commission (NRC). Project work this period continued to be concentrated in three integrated activities: site characterization, engineering design and construction, and performance assessment. Accomplishments this period and their relation to near-term objectives are briefly summarized.

  17. Meteorological data for water years 1988-94 from five weather stations at Yucca Mountain, Nevada

    SciTech Connect

    Flint, A.L.; Davies, W.J.

    1997-11-01

    This report describes meteorological data collected from five weather stations at Yucca Mountain, Nevada, from as early as April 1987 through September 1994. The measurements include solar radiation, temperature, relative humidity, wind speed, wind vector magnitude, wind direction, wind vector direction, barometric pressure, and precipitation. Measurements were made very 10 seconds and averaged every 15 minutes. The data were collected as part of the geologic and hydrologic site-characterization studies of Yucca Mountain, a potential repository for high-level radioactive waste. Precipitation at the site ranged from a low of 12 millimeters total for water year 1989 to a high of 312 millimeters total for water year 1993. Air temperature ranged from a low of 15.1 degrees Celsius in December 1990 (water year 1991) to a high of 41.9 degrees Celsius in July 1989 (water year 1989). The weather station network also provides information on the spatial variability of precipitation and temperature.

  18. Geochemistry of outcrop samples from the Raven Canyon and Paintbrush Canyon reference sections, Yucca Mountain, Nevada

    SciTech Connect

    Peterman, Z.E.; Spengler, R.W.; Singer, F.R.; Dickerson, R.P.

    1996-11-01

    The Yucca Mountain area in southern Nevada is being evaluated for its suitability as a potential site for the construction of an underground, high-level nuclear waste repository. With support from the Department of Energy, the US Geological Survey is conducting detailed petrographic, geochemical, and isotopic analyses of samples collected from drill cores and from outcrops. The geochemical and isotopic compositions of the volcanic rocks of Yucca Mountain derive from those of their parental magmas, from changes resulting from the eruptive processes and from post-depositional alteration. In this study, geochemical and isotopic data were acquired on samples from reference sections selected in areas where the effects of the post-depositional alteration has been minimal. These data will be used as baseline information for delineating and correlating zonal features in the volcanic rock alteration that may occur in the thermal aureole of the potential repository after it has been loaded with nuclear waste.

  19. Selection criteria for container materials at the proposed Yucca Mountain high level nuclear waste repository

    SciTech Connect

    Halsey, W.G.

    1989-11-01

    A geological repository has been proposed for the permanent disposal of the nation`s high level nuclear waste at Yucca Mountain in the Nevada desert. The containers for this waste must remain intact for the unprecedented service lifetime of 1000 years. A combination of engineering, regulatory, and licensing requirements complicate the container material selection. In parallel to gathering information regarding the Yucca Mountain service environment and material performance data, a set of selection criteria have been established which compare candidate materials to the performance requirements, and allow a quantitative comparison of candidates. These criteria assign relative weighting to varied topic areas such as mechanical properties, corrosion resistance, fabricability, and cost. Considering the long service life of the waste containers, it is not surprising that the corrosion behavior of the material is a dominant factor. 7 refs.

  20. Three-dimensional hydrological and thermal property models of Yucca Mountain, Nevada

    SciTech Connect

    Rautman, C.A.; McKenna, S.A.

    1997-11-01

    This report describes the creation of three-dimensional numerical models of selected rock-matrix properties for the region of the potential high-level nuclear waste repository site at Yucca Mountain, which is located in southern Nevada. The models have been generated for a majority of the unsaturated and shallow saturated zone within an area referred to within the Yucca Mountain Site Characterization project as the site area. They comprise a number of material properties of importance both to detailed process-level modeling activities and to more summary-style performance assessment modeling. The material properties within these models are both spatially variable (heterogeneous) and spatially correlated, as the rocks are understood from data obtained from site-characterization drill holes widely scattered across the site area.

  1. Analyzing flow patterns in unsaturated fractured rock of YuccaMountain using an integrated modeling approach

    SciTech Connect

    Wu, Yu-Shu; Lu, Guoping; Zhang, Keni; Pan, Lehua; Bodvarsson,Gudmundur S.

    2003-11-03

    This paper presents a series of modeling investigations to characterize percolation patterns in the unsaturated zone of Yucca Mountain, Nevada, a proposed underground repository site for storing high-level radioactive waste. The investigations are conducted using a modeling approach that integrates a wide variety of moisture, pneumatic, thermal, and isotopic geochemical field data into a comprehensive three-dimensional numerical model through model calibration. This integrated modeling approach, based on a dual-continuum formulation, takes into account the coupled processes of fluid and heat flow and chemical isotopic transport in Yucca Mountain's highly heterogeneous, unsaturated fractured tuffs. In particular, the model results are examined against different types of field-measured data and used to evaluate different hydrogeological conceptual models and their effects on flow patterns in the unsaturated zone. The objective of this work to provide understanding of percolation patterns and flow behavior through the unsaturated zone, which is a crucial issue in assessing repository performance.

  2. Multiscale Thermohydrologic Model Supporting the License Application for the Yucca Mountain Repository

    SciTech Connect

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

    2006-01-31

    The MultiScale ThermoHydrologic Model (MSTHM) predicts thermal-hydrologic (TH) conditions within emplacement tunnels (drifts) and in the adjoining host rock at Yucca Mountain, Nevada, which is the proposed site for a radioactive waste repository in the U.S. Because these predictions are used in the performance assessment of the Yucca Mountain repository, they must address the influence of variability and uncertainty of the engineered- and natural-system parameters that significantly influence those predictions. Parameter-sensitivity studies show that the MSTHM predictions adequately propagate the influence of parametric variability and uncertainty. Model-validation studies show that the influence of conceptual-model uncertainty on the MSTHM predictions is insignificant compared to that of parametric uncertainty, which is propagated through the MSTHM.

  3. Site characterization plan: Yucca Mountain Site, Nevada Research and Development Area, Nevada: Volume 9, Index

    SciTech Connect

    1988-12-01

    This site characterization plan (SCP) has been developed for the candidate repository site at Yucca Mountain in the State of Nevada. The SCP includes a description of the Yucca Mountain site (Chapters 1-5), a conceptual design for the repository (Chapter 6), a description of the packaging to be used for the waste to be emplaced in the repository (Chapter 7), and a description of the planned site characterization activities (Chapter 8). The schedules and milestones presented in Sections 8.3 and 8.5 of the SCP were developed to be consistent with the June 1988 draft Amendment to the DOE`s Mission Plan for the Civilian Radioactive Waste Management Program. The five month delay in the scheduled start of exploratory shaft construction that was announced recently is not reflected in these schedules.

  4. Welding Robot and Remote Handling System for the Yucca Mountain Waste Package Closure System

    SciTech Connect

    Barker, M.E.; Holt, T.E.; LaValle, D.R.; Pace, D.P.; Croft, K.M.; Shelton-Davis, C.V.

    2008-07-01

    In preparation for the license application and construction of a repository for housing the nation's spent nuclear fuel and high-level waste in Yucca Mountain, the Idaho National Laboratory (INL) has been charged with preparing a mock-up of a full-scale prototype system for sealing the waste packages (WP). Three critical pieces of the closure room include two PaR Systems TR4350 Telerobotic Manipulators and a PaR Systems XR100 Remote Handling System (RHS). The TR4350 Manipulators are 6-axis programmable robots that will be used to weld the WP lids and purge port cap as well as conduct nondestructive examinations. The XR100 Remote Handling System is a 4-axis programmable robot that will be used to transport the WP lids and process tools to the WP for operations and remove equipment for maintenance. The welding and RHS robots will be controlled using separate PaR 5/21 CIMROC Controllers capable of complex motion control tasks. A tele-operated PaR 4350 Manipulator will also be provided with the XR100 Remote Handling System. It will be used for maintenance and associated activities within the closure room. (authors)

  5. Total System Performance Assessment, 1993: An evaluation of the potential Yucca Mountain repository

    SciTech Connect

    Andrews, R.W.; Dale, T.F.; McNeish, J.A.

    1994-03-01

    Total System Performance Assessments are an important component in the evaluation of the suitability of Yucca Mountain, Nevada as a potential site for a mined geologic repository for the permanent disposal of high-level radioactive wastes in the United States. The Total System Performance Assessments are conducted iteratively during site characterization to identify issues which should be addressed by the characterization and design activities as well as providing input to regulatory/licensing and programmatic decisions. During fiscal years 1991 and 1992, the first iteration of Total System Performance Assessment (hereafter referred to as TSPA 1991) was completed by Sandia National Laboratories and Pacific Northwest Laboratory. Beginning in fiscal year 1993, the Civilian Radioactive Waste Management System Management and Operating Contractor was assigned the responsibility to plan, coordinate, and contribute to the second iteration of Total System Performance Assessment (hereafter referred to as TSPA 1993). This document presents the objectives, approach, assumptions, input, results, conclusions, and recommendations associated with the Management and Operating Contractor contribution to TSPA 1993. The new information incorporated in TSPA 1993 includes (1) revised estimates of radionuclide solubilities (and their thermal and geochemical dependency), (2) thermal and geochemical dependency of spent fuel waste alteration and glass dissolution rates, (3) new distribution coefficient (k{sub d}) estimates, (4) revised estimates of gas-phase velocities and travel times, and (5) revised hydrologic modeling of the saturated zone which provides updated estimates of the advective flux through the saturated zone.

  6. Interpretation of chemical and isotopic data from boreholes in the unsaturated zone at Yucca Mountain, Nevada

    SciTech Connect

    Yang, I.C.; Rattray, G.W.; Yu, P.

    1996-12-31

    Analyses of pore water from boreholes at Yucca Mountain indicate that unsaturated-zone pore water has significantly larger concentrations of chloride and dissolved solids than the saturated-zone water or perched-water bodies. Chemical compositions are of the calcium sulfate or calcium chloride types in the Paintbrush Group (Tiva Canyon, Yucca Mountain, Pah Canyon, and bedded tuffs), and sodium carbonate or bicarbonate type water in the Calico Hills Formation. Tritium profiles from boreholes at Yucca Mountain indicate tritium-concentration inversions (larger tritium concentrations are located below the smaller tritium concentration in a vertical profile) occur in many places. These inversions indicate preferential flow through fractures. Rock-gas compositions are similar to that of atmospheric air except that carbon dioxide concentrations are generally larger than those in the air. The delta carbon-13 values of gas are fairly constant from surface to 365.8 meters, indicating little interaction between the gas CO{sub 2} and caliche in the soil. Model calculations indicate that the gas transport in the unsaturated zone at Yucca Mountain agrees well with the gas-diffusion process. Tritium-modeling results indicate that the high tritium value of about 100 tritium units in the Calico Hills Formation of UZ-16 is within limits of a piston-flow model with a water residence time of 32 to 35 years. The large variations in tritium concentrations with narrow peaks imply piston flow or preferential fracture flow rather than matrix flow. In reality, the aqueous-phase flow in the unsaturated zone is between piston and well-mixed flows but is closer to a piston flow.

  7. MODELING FLOW AND TRANSPORT PATHWAYS TO THE POTENTIAL REPOSITORY HORIZON AT YUCCA MOUNTAIN

    SciTech Connect

    Wolfsberg, A. V.; Fabryka-Martin, J. T.; Roemer, G. J.C.; Robinson, B. A.

    1998-03-04

    The isotopic ratios of {sup 36}Cl/Cl are used in conjunction with geologic interpretation and numerical modeling to evaluate flow and transport pathways, processes, and model parameters in the unsaturated zone at Yucca Mountain. By synthesizing geochemical and geologic data, the numerical model results provide insight into the validity of alternative hydrologic parameter sets, flow and transport processes in and away from fault zones, and the applicability of {sup 36}Cl/Cl. ratios for evaluating alternative conceptual models.

  8. Determination of Rock Mass Modulus Using the Plate Loading Method at Yucca Mountain, Nevada

    SciTech Connect

    Finley, R.E.; George, J.T.; Riggins, M.

    1999-08-02

    A suite of plate loading tests has recently been conducted by Sandia National Laboratories at the Exploratory Studies Facility at Yucca Mountain, Nevada. Fielding of these in situ tests as well as other approaches undertaken for the determination of rock mass modulus are described. The various methodologies are evaluated and their data compared. Calculation by existing empirical methods and numerical modeling are compared to each other as well as to field data.

  9. Calculation of Post-Closure Natural Convection Heat and Mass Transfer in Yucca Mountain Drifts

    SciTech Connect

    S. Webb; M. Itamura

    2004-03-16

    Natural convection heat and mass transfer under post-closure conditions has been calculated for Yucca Mountain drifts using the computational fluid dynamics (CFD) code FLUENT. Calculations have been performed for 300, 1000, 3000, and 10,000 years after repository closure. Effective dispersion coefficients that can be used to calculate mass transfer in the drift have been evaluated as a function of time and boundary temperature tilt.

  10. Independent management and financial review, Yucca Mountain Project, Nevada. Final report, Appendix

    SciTech Connect

    1995-07-15

    The Nuclear Waste Policy Act of 1982 (Public Law 97-425), as amended by Public Law 100-203, December 22, 1987, established the Office of Civilian Radioactive Waste Management (OCRWM) within the Department of Energy (DOE), and directed the Office to investigate a site at Yucca Mountain, Nevada, to determine if this site is suitable for the construction of a repository for the disposal of high level nuclear waste. Work on site characterization has been under way for several years. Thus far, about $1.47 billion have been spent on Yucca Mountain programs. This work has been funded by Congressional appropriations from a Nuclear Waste Fund to which contributions have been made by electric utility ratepayers through electric utilities generating power from nuclear power stations. The Secretary of Energy and the Governor of the State of Nevada have appointed one person each to a panel to oversee an objective, independent financial and management evaluation of the Yucca Mountain Project. The Requirements for the work will include an analysis of (1) the Yucca Mountain financial and, contract management techniques and controls; (2) Project schedules and credibility of the proposed milestones; (3) Project organizational effectiveness and internal planning processes, and (4) adequacy of funding levels and funding priorities, including the cost of infrastructure and scientific studies. The recipient will provide monthly progress report and the following reports/documents will be presented as deliverables under the contract: (1) Financial and Contract Management Preliminary Report; (2) Project Scheduling Preliminary Report; (3)Project Organizational Effectiveness Preliminary Report; (4) Project Funding Levels and Funding Priorities Preliminary Report; and (5) Final Report.

  11. Los Alamos National Laboratory Yucca Mountain Site Characterization Project 1994 quality program status report

    SciTech Connect

    Bolivar, S.L.

    1996-03-01

    This status report is for calendar year 1994. It summarizes the annual activities and accomplishments of the Los Alamos National Laboratory Yucca Mountain Site Characterization Project (YMP or Project) quality assurance program. By identifying the accomplishments of the quality program, a baseline is established that will assist in decision making, improve administrative controls and predictability, and allow us to annually identify adverse trends and to evaluate improvements. This is the fourth annual status report.

  12. Chemical variability of zeolites at a potential nuclear waste repository, Yucca Mountain, Nevada

    SciTech Connect

    Broxton, D.E.

    1985-12-31

    The compositions of clinoptilolites and their host tuffs have been examined by electron microprobe and x-ray fluorescence, respectively, to determine their variability at a potential nuclear waste repository, Yucca Mountain, Nevada. Because of their sorptive properties, these zeolites could provide important geologic barriers to radionuclide migration. Variations in clinoptilolite composition can strongly affect the mineral`s thermal and ion-exchange properties, thus influencing its behavior in the repository environment. Clinoptilolites and heulandites closest to the proposed repository have calcium-rich compositions (60 to 90 mol. % Ca) and silica-to-aluminum ratios that concentrate between 4.0 and 4.6. In contrast, clinoptilolites and their host tuffs deeper in the volcanic sequence have highly variable compositions that vary vertically and laterally. Deeper-occurring clinoptilolites in the eastern part of Yucca Mountain are characterized by calcic-potassic compositions and tend to become more calcium-rich with depth. Clinoptilolites at equivalent stratigraphic levels on the western side of Yucca Mountain have sodic-potassic compositions and tend to become more sodium-rich with depth. Despite their differences in exchangeable cation compositions these two deeper-occurring compositional suites have similar silica-to-aluminum ratios, concentrating between 4.4 and 5.0. The chemical variability of clinoptilolites and their host tuffs at Yucca Mountain suggest that their physical and chemical properties will also vary. Compositionally-dependent clinoptilolite properties important for repository performance assessment include expansion/contraction behavior, hydration/dehydration behavior, and ion-exchange properties.

  13. Surface-discharging hydrothermal systems at Yucca Mountain: Examining the evidence

    SciTech Connect

    Levy, S.S.

    1992-12-01

    This paper discusses exposures of altered rock that have been thought to form by recent discharge of water from depth. They were examined to address a concern that hydrothermal processes could compromise the isolation capability of a potential high-level nuclear waste repository at Yucca Mountain. Suspected hot-spring and hydrothermal-vent deposits are more likely the products of infiltration of meteoric water into newly deposited and still-hot pyroclastic flows >12 Myr ago.

  14. Data Qualification Report: PRecipitation and Surface Geology Data for Use on the Yucca Mountain Project

    SciTech Connect

    C. Wilson

    2000-11-30

    The unqualified data addressed in this qualification report have been cited in an Analysis Model Report (AMR) to support the Site Recommendation in determining the suitability of Yucca Mountain as a repository for high-level radioactive waste. The unqualified data include precipitation volumes and surface geology maps The precipitation data consist of daily precipitation volumes measured at Yucca Mountain. The surface geology data include identification of the types and surface expressions of geologic units and associated structural features such as faults. These data were directly used in AMR U0010, Simulation of Net Infiltration for Modern and Potential Future Climates, ANL-NBS-HS-000032 (Hevesi et al. 2000), to estimate net infiltration into Yucca Mountain. This report evaluates the unqualified data within the context of supporting studies of this type for the Yucca Mountain Site Characterization Project (YMP). The purpose of this report is to identify data that can be cited as qualified for use in technical products to support the YMP Site Recommendation and that may also be used to support the License Application. The qualified data may either be retained in the original Data Tracking Number (DTN) or placed in new DTNs generated as a result of the evaluation. The appropriateness and limitations (if any) of the data with respect to intended use are addressed in this report. In accordance with Attachment 1 of procedure AP-3.15Q, Rev. 02, Managing Technical Product Inputs, it has been determined that the unqualified precipitation and surface geology data are not used in the direct calculation of Principal Factors for postclosure safety or disruptive events. References to tables, figures, and sections from Hevesi et al. (2000) are based on Rev. 00 of that document.

  15. Major results of gravity and magnetic studies at Yucca Mountain, Nevada

    USGS Publications Warehouse

    Oliver, H.W.; Ponce, D.A.; Sikora, R.F.

    1991-01-01

    About 4,000 gravity stations have been obtained at Yucca Mountain and vicinity since the beginning of radioactive-waste studies there in 1978. These data have been integrated with data from about 29,000 stations previously obtained in the surrounding region to produce a series of Bouguer and isostatic-residual-gravity maps of the Nevada Test Site and southeastern Nevada. Yucca Mountain is characterized by a WNW-dipping gravity gradient whereby residual values of -10 mGal along the east edge of Yucca Mountain decrease to about -38 mGal over Crater Flat. Using these gravity data, two-dimensional modeling predicted the depth to pre-Cenozoic rocks near the proposed repository to be about 1,220??150 m, an estimate that was subsequently confirmed by drilling to be 1,244 m. Three-dimensional modeling of the gravity low over Crater Flat indicates the thickness of Cenozoic volcanic rocks and alluvial cover to be about 3,000 m. Gravity interpretations also identified the Silent Canyon caldera before geologic mapping of Pahute Mesa and provided an estimate of the thickness of the volcanic section there of nearly 5 km.

  16. Independent Analysis of Seismicity and Rock fall Scenarios for the Yucca Mountain Repository

    SciTech Connect

    Apted, M.J.; Kemeny, J.M.; Martin, C.D.; James, R.J.

    2006-07-01

    Yucca Mountain is located in the somewhat seismically active Basin and Range province. Future seismic activity is identified by the US Nuclear Regulatory Commission and the US National Academy of Sciences as a key scenario for safety assessment of a proposed repository at Yucca Mountain. As part of its on-going program of conducting independent analyses of scientific and technical issues that could be important to the licensing of the Yucca Mountain repository, EPRI has conducted an analysis of the combined scenarios of seismic activity and stability of emplacement drifts with respect to the long-term repository safety. In this paper we present the results of 3D finite element simulations of both static and dynamic loading of a degraded waste package. For the static case, the expected maximum static load is determined by utilizing relationships between cave height and the bulking factor. A static load representing 30 meters of broken rock was simulated using the finite element model. For the dynamic case, block size and velocity data from the most recent Drift Degradation AMR are used. Based on this, a rock block with a volume of 3.11 m{sup 3} and with an impact velocity of 4.81 m/s was simulated using the finite element model. In both cases, the results indicate that the waste package remains intact. (authors)

  17. Yucca Mountain Site Characterization Project bibliography, 1992--1994. Supplement 4

    SciTech Connect

    1992-06-01

    Following a reorganization of the Office of Civilian Radioactive Waste Management in 1990, the Yucca Mountain Project was renamed Yucca Mountain Site Characterization Project. The title of this bibliography was also changed to Yucca Mountain Site Characterization Project Bibliography. Prior to August 5, 1988, this project was called the Nevada Nuclear Waste Storage Investigations. This bibliography contains information on this ongoing project that was added to the Department of Energy`s Energy Science and Technology Database from January 1, 1992, through December 31, 1993. The bibliography is categorized by principal project participating organization. Participant-sponsored subcontractor reports, papers, and articles are included in the sponsoring organization`s list. Another section contains information about publications on the Energy Science and Technology Database that were not sponsored by the project but have some relevance to it. Earlier information on this project can be found in the first bibliography DOE/TIC-3406, which covers 1977--1985, and its three supplements DOE/OSTI-3406(Suppl.1), DOE/OSTI-3406(Suppl.2), and DOE/OSTI-3406(Suppl.3), which cover information obtained during 1986--1987, 1988--1989, and 1990--1991, respectively. All entries in the bibliographies are searchable online on the NNW database file. This file can be accessed through the Integrated Technical Information System (ITIS) of the US Department of Energy (DOE).

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

    SciTech Connect

    Price, R. H.

    1983-08-01

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

  19. Shallow infiltration processes at Yucca Mountain, Nevada : neutron logging data 1984-93

    USGS Publications Warehouse

    Flint, Lorraine E.; Flint, Alan L.

    1995-01-01

    To determine site suitability of Yucca Mountain, Nevada, as a potential high-level radioactive waste repository, a study was devised to characterize net infiltration. This study involves a detailed data set produced from 99 neutron boreholes that consisted of volumetric water-content readings with depth from 1984 through 1993 at Yucca Mountain. Boreholes were drilled with minimal disturbance to the surrounding soil or rock in order to best represent field conditions. Boreholes were located in topographic positions representing infiltration zones identified as ridgetops, sideslopes, terraces, and active channels. Through careful field calibration, neutron moisture logs, collected on a monthly basis and representing most of the areal locations at Yucca Mountain, illustrated that the depth of penetration of seasonal moisture, important for escaping loss to evapotranspiration, was influenced by several factors. It was increased (1) by thin soil cover, especially in locations where thin soil is underlain by fractured bedrock; (2) on ridgetops; and (3) during the winter when evapotranspiration is low and runoff is less frequent. This data set helps to provide a seasonal and areal distribution of changes in volumetric water content with which to assess hydrologic processes contributing to net infiltration.

  20. Plutonium oxidation and subsequent reduction by Mn(IV) minerals in Yucca Mountain tuff.

    PubMed

    Powell, Brian A; Duff, Martine C; Kaplan, Daniel I; Fjeld, Robert A; Newville, Matthew; Hunter, Douglas B; Bertsch, Paul M; Coates, John T; Eng, Peter; Rivers, Mark L; Serkiz, Steven M; Sutton, Stephen R; Triay, Ines R; Vaniman, David T

    2006-06-01

    Plutonium oxidation state distribution on Yucca Mountain tuff and synthetic pyrolusite (beta-MnO2) suspensions was measured using synchrotron X-ray micro-spectroscopy and microimaging techniques as well as ultrafiltration/solventextraction techniques. Plutonium sorbed to the tuff was preferentially associated with manganese oxides. For both Yucca Mountain tuff and synthetic pyrolusite, Pu(IV) or Pu(V) was initially oxidized to more mobile Pu(V/VI), but over time, the less mobile Pu(IV) became the predominant oxidation state of the sorbed Pu. The observed stability of Pu(IV) on oxidizing surfaces (e.g., pyrolusite), is proposed to be due to the formation of a stable hydrolyzed Pu(IV) surface species. These findings have important implications in estimating the risk associated with the geological burial of radiological waste in areas containing Mn-bearing minerals, such as at the Yucca Mountain or the Hanford Sites, because plutonium will be predominantly in a much less mobile oxidation state (i.e., Pu(IV)) than previously suggested (i.e., Pu(V/VI). PMID:16786687

  1. Colloid transport and deposition in water-saturated Yucca Mountain tuff as determined by ionic strength.

    PubMed

    Gamerdinger, A P; Kaplan, D I

    2001-08-15

    Colloid mobility and deposition were determined in model systems consisting of quartz sand or crushed Yucca Mountain tuff, latex microspheres (colloidal particles), and simulated groundwater. Ionic strength (I) was manipulated as a first step in defining limiting conditions for colloid transport in a system modeled after geochemical conditions at the Yucca Mountain site. Solutions of deionized water (DI), 0.1x, 1x, and 10x (the ionic strength of simulated groundwater) (I = 0.0116 M) were used in saturated columns under steady-state flow conditions. Separate experiments with conservative tracers indicated stable hydrodynamic conditions that were independent of I. Colloids were completely mobile (no deposition) in the DI and 0.1x solutions; deposition increased to 11-13% for 1x and to 89-97% for 10x treatments with similar results for sand and tuff. Deposition was described as a pseudo-first-order process; however, a decreasing rate of deposition was apparent for colloid transport at the 10x condition through the tuff. A linear dependence of colloid removal (extent and deposition rate coefficient) on I is illustrated for the model Yucca Mountain system and for a glass-KCl system reported in the literature. This simple relationship for saturated systems may be useful for predicting deposition efficiencies under conditions of varying ionic strength. PMID:11529572

  2. Transport of uranium and technetium through the unsaturated tuffs, Yucca Mountain, Nevada

    SciTech Connect

    Cederberg, G.A.; Greenwade, L.E.; Travis, B.J.

    1987-12-31

    An area containing unsaturated fractured tuffs at Yucca Mountain, Nevada, is one of the potential sites for geologic storage of high-level radioactive waste. The Environmental Protection Agency (EPA) 40 CFR 191 Regulation limits the cumulative releases of many radionuclides from the repository to the accessible environment for 10,000 years after disposal [1]. Numerical models can be used to determine if the EPA containment requirement is met. In this paper a preliminary set of transport calculations for uranium and technetium is discussed. First, a foundation for the calculations, a comprehensive, referenced geochemical/geophysical model containing the current stratigraphic, petrologic, hydrogeologic, geochemical, and material data for the Yucca Mountain site was compiled. Second, the integrated transport of uranium and technetium from the repository to the water table was modeled. An expected-case flow scenario and a worse-case flow scenario were used in the calculations. The sorption of technetium was neglected in the worse-case scenario. Results show that in the case of uranium, the estimated transport was only moderately sensitive to the magnitude of the flow because sorption had a significant effect on the retardation. In the case of technetium, when sorption was neglected, the flow dominated the transport. The EPA containment requirements were met for all cases. These preliminary calculations will be used as a basis to investigate the effects of physical and geochemical processes on the long-term transport of radionuclides at Yucca Mountain. 18 references, 4 figures, 3 tables.

  3. The transport of uranium and technetium through the unsaturated tuffs, Yucca Mountain, Nevada

    SciTech Connect

    Cederberg, G.A.; Greenwade, L.E.; Travis, B.J.

    1986-12-31

    An area containing unsaturated fractured tuffs at Yucca Mountain, Nevada, is one of the potential sites for geologic storage of high-level radioactive waste. The Environmental Protection Agency (EPA) 40 CFR 191 Regulation limits the cumulative releases of many radionuclides from the repository to the accessible environment for 10,000 years after disposal. Numerical models can be used to determine if the EPA containment requirement is met. In this paper a preliminary set of transport calculations for uranium and technetium is discussed. A foundation for the calculations, a comprehensive, referenced geochemical/geophysical model containing the current stratigraphic, petrologic, hydrogeologic, geochemical, and material data for the Yucca Mountain site was compiled. The integrated transport of uranium and technetium from the repository to the water table was modeled. An expected-case flow scenario and a worse-case flow scenario were used in the calculations. The sorption of technetium was neglected in the worse-case scenario. Results show that in the case of uranium, the estimated transport was only moderately sensitive to the magnitude of the flow because sorption had a significant effect on the retardation. In the case of technetium, when sorption was neglected, the flow dominated the transport. The EPA containment requirements were met for all cases. These preliminary calculations will be used as a basis to investigate the effects of physical and geochemical processes on the long-term transport of radionuclides at Yucca Mountain. 18 refs., 4 figs., 3 tabs.

  4. Strontium isotope geochemistry of soil and playa deposits near Yucca Mountain, Nevada

    SciTech Connect

    Marshall, B.D.; Mahan, S.A.

    1994-12-31

    The isotopic composition of strontium contained in the carbonate fractions of soils provides an excellent tracer which can be used to test models for their origin. This paper reports data on surface coatings and cements, eolian sediments, playas and alluvial fan soils which help to constrain a model for formation of the extensive calcretes and fault infilling in the Yucca Mountain region. The playas contain carbonate with a wide range of strontium compositions; further work will be required to fully understand their possible contributions to the pedogenic carbonate system. Soils from an alluvial fan to the west of Yucca Mountain show that only small amounts of strontium are derived from weathering of silicate detritus. However, calcretes from a fan draining a carbonate terrane have strontium compositions dominated locally by the limestone strontium component. Although much evidence points to an eolian source for at least some of the strontium in the pedogenic carbonates near Yucca Mountain, an additional component or past variation of strontium composition in the eolian source is required to model the pedogenic carbonate system.

  5. Paleoseismic investigations of Stagecoach Road fault, southeastern Yucca Mountain, Nye County, Nevada

    SciTech Connect

    Menges, C.M.; Oswald, J.A.; Coe, J.A.; Lundstrom, S.C.; Paces, J.B.; Mahan, S.A.; Widmann, B.; Murray, M.

    1998-04-01

    This report summarizes the results of paleoseismic investigations at two trenches (SCR-T1 and SCR-T3) excavated across the Stagecoach Road (SCR) fault at the southeastern margin of Yucca Mountain. The results of these studies are based on detailed mapping or logging of geologic and structural relationships exposed in trench walls, combined with descriptions of lithologic units, associated soils, and fault-related deformation. The ages of trench deposits are determined directly from geochronologic dating of selected units and soils, supplemented by stratigraphic and soil correlations with other surficial deposits in the Yucca Mountain area. The time boundaries used in this report for subdivision of the Quaternary period are listed in a table. These data and interpretations are used to identify the number, amounts, timing, and approximately lengths of late to middle Quaternary (less than 200 ka) surface-faulting events associated with paleoearthquakes at the trench sites. This displacement history forms the basis for calculating paleoearthquake recurrence intervals and fault-slip rates for the Stagecoach Road fault and allows comparison with fault behavior on other Quaternary faults at or near Yucca Mountain.

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

    SciTech Connect

    Broxton, D.E.

    1987-12-31

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

  7. The role of fault zone in affecting multiphase flow at Yucca Mountain

    SciTech Connect

    Tsang, Y.W.; Pruess, K.; Wang, J.S.Y.

    1993-12-31

    Within Yucca Mountain, the potential High Level Nuclear-Waste Repository site, there are large scale fault zones, most notably the Ghost Dance Fault. The effect of such high-permeability, large-scale discontinuities on the flow and transport is a question of concern in assessing the ability of the site to isolate radio-nuclides from the biosphere. In this paper, we present a numerical study to investigate the role of the fault in affecting both the liquid and gas phase flows in the natural state at Yucca Mountain prior to waste emplacement, as well as after the waste emplacement when the fluid flow is strongly heat-driven. Our study shows that if the characteristic curves of the Ghost Dance Fault obey the same relationship between saturated permeability and capillary scaling parameter, is as observed from the measured data of Yucca Mountain welded and nonwelded tuffs, Apache Leap tuffs, and Las Cruces soil, then a large saturated permeability of the Ghost Dance Fault will play little role in channeling water into the fault, or in enhancing the flow of water down the fault. However, the Fault may greatly enhance the upward gas flow after emplacement of waste. This may have implications on the transport of gaseous radio-nuclides such as C{sup 14}. The results of this study also focus attention on the need for field measurements of fluid flow in the fault zones.

  8. The role of fault zones in affecting multiphase flow at Yucca Mountain

    SciTech Connect

    Tsang, Y.W.; Pruess, K.; Wang, J.S.Y.

    1993-01-01

    Within Yucca Mountain, the potential High Level Nuclear-Waste Repository site, there are large scale fault zones, most notably the Ghost Dance Fault. The effect of such high-permeability, large scale discontinuities on the flow and transport is a question of concern in assessing the ability of the site to isolate radio-nuclides from the biosphere. In this paper, we present a numerical study to investigate the role of the fault in affecting both the liquid and gas phase flows in the natural state at Yucca Mountain prior to waste emplacement, as well as after the waste emplacement when the fluid flow is strongly heat-driven. Our study shows that if the characteristic curves of the Ghost Dance Fault obey the same relationship between saturated permeability and capillary scaling parameter, as is observed from the measured data of Yucca Mountain welded and nonwelded tuffs. Apache Leap tuffs, and Las Cruces soil, then a large saturated permeability of the Ghost Dance Fault will play little role in channeling water into the fault, or inenhancing the flow of water down the fault. However, the Fault may greatly enhance the upward gas flow after emplacement of waste. This may have implications on the transport of gaseous radio-nuclides such as C{sup 14}. The results of this study also focus attention on the need for field measurements of fluid flow in the fault zones.

  9. Shallow infiltration processes at Yucca Mountain, Nevada - neutron logging data 1984-93

    SciTech Connect

    Flint, L.E.; Flint, A.L.

    1995-11-01

    To determine site suitability of Yucca Mountain, Nevada, as a potential high-level radioactive waste repository, a study was devised to characterize net infiltration. This study involves a detailed data set produced from 99 neutron boreholes that consisted of volumetric water-content readings with depth from 1984 through 1993 at Yucca Mountain. Boreholes were drilled with minimal disturbance to the surrounding soil or rock in order to best represent field conditions. Boreholes were located in topographic positions representing infiltration zones identified as ridge-tops, sideslopes, terraces, and active channels. Through careful field calibration, neutron moisture logs, collected on a monthly basis and representing most of the areal locations at Yucca Mountain, illustrated that the depth of penetration of seasonal moisture, important for escaping loss to evapotranspiration, was influenced by several factors. It was increased (1) by thin soil cover, especially in locations where thin soil is underlain by fractured bedrock; (2) on ridgetops; and (3) during the winter when evapotranspiration is low and runoff is less frequent. This data set helps to provide a seasonal and areal distribution of changes in volumetric water content with which to assess hydrologic processes contributing to net infiltration.

  10. Shallow infiltration processes at Yucca Mountain, Nevada: Neutron logging data 1984--1993

    SciTech Connect

    Flint, L.E.; Flint, A.L.

    1995-12-31

    To determine site suitability of Yucca Mountain, Nevada, as a potential high-level radioactive waste repository, a study was devised to characterize net infiltration. This study involves a detailed data set produced from 99 neutron boreholes that consisted of volumetric water-content readings with depth from 1984 through 1993 at Yucca Mountain. Boreholes were drilled with minimal disturbance to the surrounding soil or rock in order to best represent field conditions. Boreholes were located in topographic positions representing infiltration zones identified as ridgetops, sideslopes, terraces, and active channels. Through careful field calibration, neutron moisture logs, collected on a monthly basis and representing most of the areal locations at Yucca Mountain, illustrated that the depth of penetration of seasonal moisture, important for escaping loss to evapotranspiration, was influenced by several factors. It was increased (1) by thin soil cover, especially in locations where thin soil is underlain by fractured bedrock; (2) on ridgetops; and (3) during the winter when evapotranspiration is low and runoff is less frequent. This data set helps to provide a seasonal and areal distribution of changes in volumetric water content with which to assess hydrologic processes contributing to net infiltration.

  11. Mineralogy of drill hole UE-25p#1 at Yucca Mountain, Nevada

    SciTech Connect

    Chipera, S.J.; Bish, D.L.

    1988-05-01

    Drill hole UE-25p{number_sign}1 is located east of the candidate repository block at Yucca Mountain, Nevada, and as such provides information on the geology of the accessible environment. The hole was drilled to a depth of 1807 m (5923 ft) and is unique in that it penetrates tuffs that are older than any volcanic units previously encountered in drill holes at Yucca Mountain. In addition, it is the only hole drilled to date that penetrates the base of the tuff sequence and enters the underlying Paleozoic dolomite basement. We have examined the mineralogy of drill cuttings, core, and sidewall samples from drill hole UE-25p{number_sign}1 is similar to that in the other drill holes examined at Yucca Mountain. The only significant differences in mineralogy from other drill holes include the presence of dolomite in the Paleozoic carbonate rocks and the occurrence of up to 3% laumontite, a Ca-zeolite, in four samples of the Lithic Ridge Tuff. 15 refs., 5 figs., 4 tabs.

  12. Evaporation of J13 and UZ pore waters at Yucca Mountain

    SciTech Connect

    Rosenberg, N D; Gdowski, G E; Knauss, K G

    2000-10-01

    This work is motivated by a need to characterize the chemistry of aqueous films that might form at elevated temperatures on engineered components at the potential high-level, nuclear-waste repository at Yucca Mountain, Nevada. Such aqueous films might form through evaporation of water that seeps into the drifts, or by water vapor absorption by hydroscopic salts directly deposited on these components (possibly from previous evaporation events or possibly from air-blown particles drawn into the drifts through a drift ventilation system). There is no consensus at this time on the chemical composition of water that might come in contact with engineered components at Yucca Mountain. Two possibilities have received the most attention: well J13 water and pore waters from the unsaturated zone (UZ) above the repository horizon. These waters represent the two major types of natural waters at Yucca Mountain. Well J13 water is a dilute Na-HCO{sub 3}-CO{sub 3} water, representative of regional perched water and groundwater. The UZ pore waters are Ca-Cl-SO{sub 4}-rich waters with a higher dissolved ion content. These waters are less well-characterized. We have studied the evaporative evolution of these two major types of waters through a series of open system laboratory experiments, with and without crushed repository-horizon tuff present, conducted at sub-boiling temperatures (75 C-85 C).

  13. Communicating credibly in an incredible environment-yucca mountain public outreach tools and techniques

    SciTech Connect

    Sheldon, S.R.; Muller, E.

    2007-07-01

    Open disclosure and public understanding of major issues surrounding the Yucca Mountain Project is a consistent goal for Clark County, Nevada, which represents nearly 80 percent of Nevada's total population. Recent enhancements to the County's communication methods employ emerging technology as well as traditional public relations tactics. The County's communication methods engage the public through highly visual displays, exhibits, informative and entertaining video programs, school presentations, creative print inserts, public interaction and news media. The program provides information based on the county's research studies and findings on property values, the environment, tourism, public health and safety, increased costs for emergency services and the potential disproportionate effects to Native American tribes and other minority populations in the area. Multi-cultural Dialogue: Nevada, particularly southern Nevada and the Las Vegas area, has experienced explosive growth in the last decade. The fastest growing demographic group in Nevada is Hispanics (nearly 23% in Las Vegas) and Asians (approx. 8%). Clark County's Nuclear Waste's Multi-cultural Program is designed to reach residents from these emerging segments of our population. Educational video programs: While officially opposed to the project, Clark County is committed to providing Nevada residents with accurate, timely and objective information about Yucca Mountain and its potential impacts to our state. Since the actual operation of the repository, if approved by the Nuclear Regulatory Commission, is about a decade away, the program includes presentations for middle and high school students on age-appropriate topics. Work with indigenous tribes: American Indian tribes in Southern Nevada participated in an unprecedented video program presenting the unique views and perspectives of the American Indian tribes directly impacted by the proposed repository. Monitoring program: To track economic, fiscal and

  14. The Enhanced Plan for Features, Events, and Processes (FEPS) at Yucca Mountain

    SciTech Connect

    G. Freeze

    2002-03-25

    A performance assessment is required to demonstrate compliance with the post-closure performance objectives for the Yucca Mountain Project (YMP), as stated in 10 CFR Part 63.1 13 (66 FR 55732, p. 55807). A performance assessment is defined in 10 CFR 63.2 (66 FR 55732, p. 55794) as an analysis that: (1) identifies the features, events, and processes (FEPs) that might affect the potential geologic repository; (2) examines the effects of those FEPs upon the performance of the potential geologic repository; and (3) estimates the expected dose incurred by a specified reasonably maximally exposed individual as a result of releases caused by significant FEPs. The performance assessment must also provide the technical basis for inclusion or exclusion of specific FEPs in the performance assessment as stated in 10 CFR 63.114 (66 FR 55732, p. 55807). An initial approach for FEP development, in support of the Total System Performance Assessment for the Site Recommendation (TSPA-SR) (CRWMS M&O 2000e), was documented in Freeze et al. (2001). The development of a comprehensive list of FEPs potentially relevant to the post-closure performance of the potential Yucca Mountain repository is an ongoing, iterative process based on site-specific information, design, and regulations. Although comprehensiveness of the FEPs list cannot be proven with absolute certainty, confidence can be gained through a combination of formal and systematic reviews (both top-down and bottom-up), audits, and comparisons with other FEP lists and through the application of more than one classification scheme. To support TSPA-SR, DOE used a multi-step approach for demonstrating comprehensiveness of the initial list of FEPs. Input was obtained from other international radioactive waste disposal programs as compiled by the Nuclear Energy Agency (NEA) of the Organization for Economic Co-operation and Development (OECD) to establish a general list of FEPs. The list was subsequently refined to include YMP

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

    SciTech Connect

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

    1993-10-01

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

  16. Bedrock geologic map of the Yucca Mountain area, Nye County, Nevada

    SciTech Connect

    Day, W.C.; Potter, C.J.; Sweetkind, D.S.; Fridrich, C.J.; Dickerson, R.P.; San Juan, C.A.; Drake, R.M. II

    1998-11-01

    Yucca Mountain, Nye County, Nevada, has been identified as a potential site for underground storage of high-level radioactive nuclear waste. Detailed bedrock geologic maps form an integral part of the site characterization program by providing the fundamental framework for research into the geologic hazards and hydrologic behavior of the mountain. This bedrock geologic map provides the geologic framework and structural setting for the area in and adjacent to the site of the potential repository. The study area comprises the northern and central parts of Yucca Mountain, located on the southern flank of the Timber Mountain-Oasis Valley caldera complex, which was the source for many of the volcanic units in the area. The Timber Mountain-Oasis Valley caldera complex is part of the Miocene southwestern Nevada volcanic field, which is within the Walker Lane belt. This tectonic belt is a northwest-striking megastructure lying between the more active Inyo-Mono and Basin-and-Range subsections o f the southwestern Great Basin.

  17. 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

  18. YUCCA MOUNTAIN SITE CHARACTERIZATIONS PROJECT TUNNEL BORING MACHINE (TBM) SYSTEM SAFETY ANALYSIS

    SciTech Connect

    N /A

    1997-02-19

    The purpose of this analysis is to systematically identify and evaluate hazards related to the tunnel boring machine (TBM) used in the Exploratory Studies Facility (ESF) at the Yucca Mountain Site Characterization Project. This process is an integral part of the systems engineering process; whereby safety is considered during planning, design, testing, and construction. Since the TBM is an ''as built'' system, the M&O is conducting the System Safety Analysis during the construction or assembly phase of the TBM. A largely qualitative approach was used since a radiological System Safety Analysis is not required. The risk assessment in this analysis characterizes the accident scenarios associated with the TBM in terms of relative risk and includes recommendations for mitigating all identified risks. The priority for recommending and implementing mitigation control features is: (1) Incorporate measures to reduce risks and hazards into the system/subsystem/component design, (2) add safety features and capabilities to existing designs, and (3) develop procedures and conduct training to increase worker awareness of potential hazards, on methods to reduce exposure to hazards, and on the actions required to avoid accidents or correct hazardous conditions. The scope of this analysis is limited to the TBM during normal operations, excluding hazards occurring during assembly and test of the TBM or maintenance of the TBM equipment.

  19. A Framework for the Analysis of Localized Corrosion at the Proposed Yucca Mountain Repository

    SciTech Connect

    Payer, J H; Carroll, S A; Gdowski, G E; Rebak, R B; Michels, T C; Miller, M C; Henson, V E

    2006-01-10

    The proposed Repository presents a familiar materials performance application that is regularly encountered in energy, transportation and other industries. The widely accepted approach to dealing with materials performance is to identify the performance requirements, to determine the operating conditions to which materials will be exposed and to select materials of construction that perform well in those conditions. A special feature of the proposed Yucca Mountain Repository is the extremely long time frame of interest, i.e. 10,000's of years and longer. Thus, the time evolution of the environment in contact with waste package surfaces and the time evolution of corrosion damage that may result are of primary interest in the determination of expected performance. An approach is presented to the analysis of localized corrosion during a time period when it is possible for waters from drips and seepage to contact the waste package surfaces, and the analysis is demonstrated for the water chemistry of mixed salt solutions and a set of time-temperature-relative humidity profiles for a hot, mid and cool temperature waste package. Based on the analysis, there are large time periods when localized corrosion can not be supported, and no corrosion damage will occur. Further analysis can then focus on time periods when it is possible for localized corrosion to occur and the determination of the evolution of any corrosion damage.

  20. 1984 Biotic Studies of Yucca Mountain, Nevada Test Site, Nye County, Nevada

    SciTech Connect

    Collins, E.; O`Farrell, T.P.

    1985-02-01

    A portion of Yucca Mountain on and adjacent to the US Department of Energy`s Nevada Test Site, Nye County, Nevada, is being considered as a possible location for a national high-level radioactive waste repository. The geologic and environmental characteristics of the site are being investigated to determine its suitability for further characterization. Goals of biotic studies were to identify species of concern, describe major floral and faunal associations, determine exposure levels of external background radiation, and assess possible impacts of characterization and operational activities. The species composition of dominant small mammals inhabiting major vegetation associations in 1984 varied little compared with results of similar surveys conducted in 1982 and 1983. Total captures were lower and reproduction was apparently curtailed. Merriam`s kangaroo rat and the long tailed pocket mouse continued to be the most abundant species. Diversity of resident species did not differ significantly between the trapping lines. The composition and relative abundance of associated species was more variable. Western harvest mice were trapped for the first time, but pinyon mice, which were present in prior years, were not trapped. Five desert tortoises were observed during surveys of possible sites for repository surface facilities. 25 refs., 4 figs., 5 tabs.

  1. Experimental and numerical simulation of dissolution andprecipitation: Implications for fracture sealing at Yucca Mountain,Nevada

    SciTech Connect

    Dobson, Patrick F.; Kneafsey, Timothy J.; Sonnenthal, Eric L.; Spycher, Nicolas; Apps, John A.

    2001-08-31

    Plugging of flow paths caused by mineral precipitation in fractures above the potential repository at Yucca Mountain, Nevada, would reduce the probability of water seeping into the repository. As part of an ongoing effort to evaluate thermal-hydrologic-chemical (THC) effects on flow in fractured media, we performed a laboratory experiment and numerical simulations to investigate mineral dissolution and precipitation under anticipated temperature and pressure conditions in the repository. To replicate mineral dissolution by vapor condensate in fractured tuff, water was flowed through crushed Yucca Mountain tuff at 94 C. The resulting steady-state fluid composition had a total dissolved solids content of about 140 mg/L; silica was the dominant dissolved constituent. A portion of the steady-state mineralized water was flowed into a vertically oriented planar fracture in a block of welded Topopah Spring Tuff that was maintained at 80 C at the top and 130 C at the bottom. The fracture began to seal with amorphous silica within five days. A 1-D plug-flow numerical model was used to simulate mineral dissolution, and a similar model was developed to simulate the flow of mineralized water through a planar fracture, where boiling conditions led to mineral precipitation. Predicted concentrations of the major dissolved constituents for the tuff dissolution were within a factor of 2 of the measured average steady-state compositions. The mineral precipitation simulations predicted the precipitation of amorphous silica at the base of the boiling front, leading to a greater than fifty-fold decrease in fracture permeability in 5 days, consistent with the laboratory experiment. These results help validate the use of a numerical model to simulate THC processes at Yucca Mountain. The experiment and simulations indicated that boiling and concomitant precipitation of amorphous silica could cause significant reductions in fracture porosity and permeability on a local scale. However

  2. Experimental and numerical simulation of dissolution and precipitation: implications for fracture sealing at Yucca Mountain, Nevada.

    PubMed

    Dobson, Patrick F; Kneafsey, Timothy J; Sonnenthal, Eric L; Spycher, Nicolas; Apps, John A

    2003-01-01

    Plugging of flow paths caused by mineral precipitation in fractures above the potential repository at Yucca Mountain, Nevada could reduce the probability of water seeping into the repository. As part of an ongoing effort to evaluate thermal-hydrological-chemical (THC) effects on flow in fractured media, we performed a laboratory experiment and numerical simulations to investigate mineral dissolution and precipitation under anticipated temperature and pressure conditions in the repository. To replicate mineral dissolution by vapor condensate in fractured tuff, water was flowed through crushed Yucca Mountain tuff at 94 degrees C. The resulting steady-state fluid composition had a total dissolved solids content of about 140 mg/l; silica was the dominant dissolved constituent. A portion of the steady-state mineralized water was flowed into a vertically oriented planar fracture in a block of welded Topopah Spring Tuff that was maintained at 80 degrees C at the top and 130 degrees C at the bottom. The fracture began to seal with amorphous silica within 5 days.A 1-D plug-flow numerical model was used to simulate mineral dissolution, and a similar model was developed to simulate the flow of mineralized water through a planar fracture, where boiling conditions led to mineral precipitation. Predicted concentrations of the major dissolved constituents for the tuff dissolution were within a factor of 2 of the measured average steady-state compositions. The mineral precipitation simulations predicted the precipitation of amorphous silica at the base of the boiling front, leading to a greater than 50-fold decrease in fracture permeability in 5 days, consistent with the laboratory experiment.These results help validate the use of a numerical model to simulate THC processes at Yucca Mountain. The experiment and simulations indicated that boiling and concomitant precipitation of amorphous silica could cause significant reductions in fracture porosity and permeability on a local

  3. 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

  4. 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

  5. Earthquake-induced water-level fluctuations at Yucca Mountain, Nevada, June 1992

    SciTech Connect

    O`Brien, G.M.

    1993-07-01

    This report presents earthquake-induced water-level and fluid-pressure data for wells in the Yucca Mountain area, Nevada, during June 1992. Three earthquakes occurred which caused significant water-level and fluid-pressure responses in wells. Wells USW H-5 and USW H-6 are continuously monitored to detect short-term responses caused by earthquakes. Two wells, monitored hourly, had significant, longer-term responses in water level following the earthquakes. On June 28, 1992, a 7.5-magnitude earthquake occurred near Landers, California causing an estimated maximum water-level change of 90 centimeters in well USW H-5. Three hours later a 6.6-magnitude earthquake occurred near Big Bear Lake, California; the maximum water-level fluctuation was 20 centimeters in well USW H-5. A 5.6-magnitude earthquake occurred at Little Skull Mountain, Nevada, on June 29, approximately 23 kilometers from Yucca Mountain. The maximum estimated short-term water-level fluctuation from the Little Skull Mountain earthquake was 40 centimeters in well USW H-5. The water level in well UE-25p {number_sign}1, monitored hourly, decreased approximately 50 centimeters over 3 days following the Little Skull Mountain earthquake. The water level in UE-25p {number_sign}1 returned to pre-earthquake levels in approximately 6 months. The water level in the lower interval of well USW H-3 increased 28 centimeters following the Little Skull Mountain earthquake. The Landers and Little Skull Mountain earthquakes caused responses in 17 intervals of 14 hourly monitored wells, however, most responses were small and of short duration. For several days following the major earthquakes, many smaller magnitude aftershocks occurred causing measurable responses in the continuously monitored wells.

  6. 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

  7. Age and character of basaltic rocks of the Yucca Mountain region, southern Nevada

    USGS Publications Warehouse

    Fleck, R.J.; Turrin, B.D.; Sawyer, D.A.; Warren, R.G.; Champion, D.E.; Hudson, M.R.; Minor, S.A.

    1996-01-01

    Volcanism in the Yucca Mountain region of southern Nevada in the last 5 m.y. is restricted to moderate-to-small volumes of subalkaline basaltic magmas, produced during at least 6 intervals, and spanning an age range from 4.6 Ma to about 125 ka. Where paleomagnetic evidence is available, the period of volcanism at individual eruptive centers apparently was geologically short-lived, even where multiple eruptions involved different magma types. K-Ar studies are consistent with most other geochronologic information, such as the minimum ages of exposure-dating techniques, and show no evidence of renewed volcanism after a significant quiescence at any of the centers in the Yucca Mountain region. A volcanic recurrence interval of 860 ?? 350 kyr is computed from a large K-Ar data set and an evaluation of their uncertainties. Monte Carlo error propagations demonstrate the validity of uncertainties obtained for weighted-mean ages when modified using the goodness of fit parameter, MSWD. Elevated 87Sr/86Sr initial ratios (Sri) in the basalts, nearly constant at 0.707, combined with low SiO2 and Rb/Sr ratios indicate a subcontinental, lithospheric mantle source, previously enriched in radiogenic Sr and depleted in Rb. Beginning with eruptions of the most voluminous eruptive center, the newly dated Pliocene Thirsty Mountain volcano, basaltic magmas have decreased in eruptive volume, plagioclase-phenocryst content, various trace element ratios, and TiO2, while increasing in light rare earth elements, U, Th, P2O5, and light REE/heavy REE ratios. These time-correlated changes are consistent with either increasing depths of melting or a decreasing thermal gradient in the Yucca Mountain region during the last 5 m.y.

  8. Temporal Damping Effect of the Yucca Mountain Fractured Saturated Rock on Transient Infiltration Pulses

    SciTech Connect

    K. Zhang; Y.S. Wu; L. Pan

    2006-05-02

    Performance assessment of the Yucca Mountain unsaturated zone (UZ) as the site for an underground repository of high-level radioactive waste relies on the crucial assumption that water percolation processes in the unsaturated zone can be approximated as a steady-state condition. Justification of such an assumption is based on temporal damping effects of several geological units within the unsaturated tuff formation. In particular, the nonwelded tuff of the Paintbrush Group (PTn unit) at Yucca Mountain, because of its highly porous nature, has been conceptualized to have a significant capacity for temporally damping transient percolation fluxes. The objective of this study is to investigate these damping effects, using a three-dimensional (3-D) mountain-scale model as well as several one-dimensional (1-D) models. The 3-D model incorporates a wide variety of the updated field data for the highly heterogeneous unsaturated formation at Yucca Mountain. The model is first run to steady state and calibrated using field-measured data and then transient pulse infiltrations are applied to the model top boundary. Subsequent changes in percolation fluxes at the bottom of and within the PTn unit are examined under episodic infiltration boundary conditions. The 1-D model is used to examine the long-term response of the flow system to higher infiltration pulses, while the damping effect is also investigated through modeling tracer transport in the UZ under episodic infiltration condition. Simulation results show the existence of damping effects within the PTn unit and also indicate that the assumption of steady-state flow conditions below the PTn unit is reasonable. However, the study also finds that some fast flow paths along faults exist, causing vertical-flux quick responses at the PTn bottom to the episodic infiltration at the top boundary.

  9. Review of Microbial Responses to Abiotic Environmental Factors in the Context of the Proposed Yucca Mountain Repository

    SciTech Connect

    Meike, A.; Stroes-Gascoyne, S.

    2000-08-01

    A workshop on Microbial Activities at Yucca Mountain (May 1995, Lafayette, CA) was held with the intention to compile information on all pertinent aspects of microbial activity for application to a potential repository at Yucca Mountain. The findings of this workshop set off a number of efforts intended to eventually incorporate the impacts of microbial behavior into performance assessment models. One effort was to expand an existing modeling approach to include the distinctive characteristics of a repository at Yucca Mountain (e.g., unsaturated conditions and a significant thermal load). At the same time, a number of experimental studies were initiated as well as a compilation of relevant literature to more thoroughly study the physical, chemical and biological parameters that would affect microbial activity under Yucca Mountain-like conditions. This literature search (completed in 1996) is the subject of the present document. The collected literature can be divided into four categories: (1) abiotic factors, (2) community dynamics and in-situ considerations, (3) nutrient considerations and (4) transport of radionuclides. The complete bibliography represents a considerable resource, but is too large to be discussed in one document. Therefore, the present report focuses on the first category, abiotic factors, and a discussion of these factors in order to facilitate the development of a model for Yucca Mountain.

  10. Geochemical similarities between volcanic units at Yucca Mountain and Pahute Mesa: evidence for a common magmatic origin for volcanic sequences that flank the Timber Mountain Caldera

    SciTech Connect

    Warren, R.G.

    1983-12-31

    Chemical compositions have been determined for sanidine, plagioclase, biotite, and hornblende phenocrysts by electron microprobe for a comprehensive set of samples of Crater Flat Tuff and tuffs of Calico Hills. Most of these samples were obtained from drill holes at Yucca Mountain. Samples of tuffs and lavas of Area 20, obtained from locations at Pahute Mesa, have similarly been subjected to microprobe analysis. Complete modal petrography has been determined for all samples. Biotite and hornblende in the samples from both Yucca Mountain and Pahute Mesa have Fe-rich compositions that contract strikingly with Fe-poor compositions in the overlying Paintbrush Tuff and the underlying Lithic Ridge Tuff at Yucca Mountain. Each unit from Yucca Mountain has distinctive compositions for both sanidine and plagioclase that very closely match compositions for a corresponding unit identified within the lower, middle and upper portions of the Area 20 tuffs and lavas from Pahute Mesa. Each of these paired units probably originated from a common parental magma and was eruptd contemporaneously or nearly so. Each pair of units with matching phenocryst chemistries has a similar, but not identical set of petrographic characteristics. The petrographic differences, as well as small differences in phenocryst chemistry, result from a sonal distribution of phenocrysts within the parent magma chamber and eruption through earlier units that differ markedly between Yucca Mountain and Pahute Mesa.

  11. A synopsis of analyses (1981--87) performed to assess the stability of underground excavations at Yucca Mountain; Yucca Mountain Project

    SciTech Connect

    Ehgartner, B.L.; Kalinski, R.C.

    1988-12-01

    This paper reviews 14 analyses that were performed by 10 different investigators during the course of 7 yr to assess the preclosure (up to 100 yr) stability of underground excavations for a potential nuclear waste repository located at Yucca Mountain, Nevada. The analyses were primarily based on thermomechanical models of the conceptual design of shafts and drifts. The material properties, codes, and design configurations used in the analyses varied because of the acquisition of additional data and refinement in codes and design over that period of time. However, all the analyses indicate that shafts and drifts can be constructed and will remain stable with minimum ground support through decommissioning of the repository. This information supports the feasibility of constructing a safe exploratory shaft facility and the expectation that it will remain stable should repository construction and waste emplacement follow. 63 refs., 2 tabs.

  12. Mineralogy, petrology and whole-rock chemistry data compilation for selected samples of Yucca Mountain tuffs; Yucca Mountain Site Characterization Project

    SciTech Connect

    Connolly, J.R.

    1991-12-01

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

  13. Summary and evaluation of existing geological and geophysical data near prospective surface facilities in Midway Valley, Yucca Mountain Project, Nye County, Nevada; Yucca Mountain Site Characterization Project

    SciTech Connect

    Gibson, J.D.; Swan, F.H.; Wesling, J.R.; Bullard, T.F.; Perman, R.C.; Angell, M.M.; DiSilvestro, L.A.

    1992-01-01

    Midway Valley, located at the eastern base of the Yucca Mountain in southwestern Nevada, is the preferred location of the surface facilities for the potential high-level nuclear waste repository at Yucca Mountain. One goal in siting these surface facilities is to avoid faults that could produce relative displacements in excess of 5 cm in the foundations of the waste-handling buildings. This study reviews existing geologic and geophysical data that can be used to assess the potential for surface fault rupture within Midway Valley. Dominant tectonic features in Midway Valley are north-trending, westward-dipping normal faults along the margins of the valley: the Bow Ridge fault to the west and the Paintbrush Canyon fault to the east. Published estimates of average Quaternary slip rates for these faults are very low but the age of most recent displacement and the amount of displacement per event are largely unknown. Surface mapping and interpretive cross sections, based on limited drillhole and geophysical data, suggest that additional normal faults, including the postulated Midway Valley fault, may exist beneath the Quaternary/Tertiary fill within the valley. Existing data, however, are inadequate to determine the location, recency, and geometry of this faulting. To confidently assess the potential for significant Quaternary faulting in Midway Valley, additional data are needed that define the stratigraphy and structure of the strata beneath the valley, characterize the Quaternary soils and surfaces, and establish the age of faulting. The use of new and improved geophysical techniques, combined with a drilling program, offers the greatest potential for resolving subsurface structure in the valley. Mapping of surficial geologic units and logging of soil pits and trenches within these units must be completed, using accepted state-of-the-art practices supported by multiple quantitative numerical and relative age-dating techniques.

  14. Report of the Peer Review Panel on the early site suitability evaluation of the Potential Repository Site at Yucca Mountain, Nevada; Yucca Mountain Site Characterization Project

    SciTech Connect

    1992-01-01

    The US Department of Energy (DOE) Yucca mountain Site Characterization Project Office (YMPO) assigned Science Applications International Corporation (SAIC), the Technical and Management Support Services (T&MSS) contractor to the YmPo, the task of conducting an Early Site Suitability Evaluation (ESSE) of the Yucca mountain site as a potential site for a high-level radioactive waste repository. First, the assignment called for the development of a method to evaluate a single site against the DOE General Guidelines for Recommendation of Sites for Nuclear Waste Repositories, 10 CFR Part 960. Then, using this method, an evaluation team, the ESSE Core Team, of senior YMP scientists, engineers, and technical experts, evaluated new information obtained about the site since publication of the final Environmental Assessment (DOE, 1986) to determine if new suitability/unsuitability findings could be recommended. Finally, the Core Team identified further information and analyses needed to make final determinations for each of the guidelines. As part of the task, an independent peer review of the ESSE report has been conducted. Expertise was solicited that covered the entire spectrum of siting guidelines in 10 CFR Part 960 in order to provide a complete, in-depth critical review of the data evaluated and cited in the ESSE report, the methods used to evaluate the data, and the conclusions and recommendations offered by the report. Fourteen nationally recognized technical experts (Table 2) served on the Peer Review Panel. The comments from the Panel and the responses prepared by the ESSE Core Team, documented on formal Comment Response Forms, constitute the body of this document.

  15. Conceptual, experimental and computational approaches to support performance assessment of hydrology and chemical transport at Yucca Mountain; Yucca Mountain Site Characterization Project

    SciTech Connect

    Narasimhan, T.N.; Wang, J.S.Y.

    1992-07-01

    The authors of this report have been participating in the Sandia National Laboratory`s hydrologic performance assessment of the Yucca Mountain, Nevada, since 1983. The scope of this work is restricted to the unsaturated zone at Yucca Mountain and to technical questions about hydrology and chemical transport. The issues defined here are not to be confused with the elaborate hierarchy of issues that forms the framework of the US Department of Energy plans for characterizing the site (DOE, 1989). The overall task of hydrologic performance assessment involves issues related to hydrology, geochemistry, and energy transport in a highly heterogeneous natural geologic system which will be perturbed in a major way by the disposal activity. Therefore, a rational evaluation of the performance assessment issues must be based on an integrated appreciation of the aforesaid interacting processes. Accordingly, a hierarchical approach is taken in this report, proceeding from the statement of the broad features of the site that make it the site for intensive studies and the rationale for disposal strategy, through the statement of the fundamental questions that need to be answered, to the identification of the issues that need resolution. Having identified the questions and issues, the report then outlines the tasks to be undertaken to resolve the issues. The report consists essentially of two parts. The first part deals with the definition of issues summarized above. The second part summarizes the findings of the authors between 1983 and 1989 under the activities of the former Nevada Nuclear Waste Storage Investigations (NNWSI) and the current YMP.

  16. Relict colluvial boulder deposits as paleoclimatic indicators in the Yucca Mountain region, southern Nevada

    SciTech Connect

    Whitney, J.W.; Harrington, C.D.

    1993-08-01

    Six colluvial boulder deposits from Yucca Mountain, Nye County, Nevada, were dated by cation-ratio dating of rock varnish accreted on boulder surfaces. Estimated minimum ages of these boulder deposits range from 760 to 170 ka. Five additional older deposits on nearby Skull and Little Skull Mountains and Buckboard Mesa yielded cation-ratio minimum-age estimates of 1.38 Ma to 800 ka. An independent cosmogenic chlorine-36 surface exposure date was obtained on one deposit, which confirms an estimated early to middle Quaternary age. These deposits have provided the oldest age estimates for unconsolidated hillslope deposits in the southwestern United States. We suggest that the colluvial boulder deposits were produced during early and middle Pleistocene glacial/pluvial episodes and were stabilized during the transition to drier interglacial climates. By comparison to modern periglacial environments, winter minimum monthly temperatures of -3 to -5 {degree}C were necessary to initiate freeze-thaw conditions of such vigor to physically weather relatively large volumes of large boulders from the upper hillslopes of the Yucca Mountain area. These conditions imply that early and middle Pleistocene glacial winter temperature were at least 1 to 3{degree}C colder than existed during the last Pleistocene glacial episode and 7 to 9{degree}C colder than present. 53 refs., 9 figs., 3 tabs.

  17. Selected ground-water data for Yucca Mountain Region, southern Nevada and eastern California, through December 22

    SciTech Connect

    La Camera, R.J.; Westenburg, C.L.

    1994-08-01

    The U.S. Geological Survey, in support of the U.S. Department of Energy, Yucca Mountain Site-Characterization Project, collects, compiles, and summarizes hydrologic data in the Yucca Mountain region. The data are collected to allow assessments of ground-water resources during studies to determine the potential suitability of Yucca Mountain for storing high-level nuclear waste. Data on ground-water levels at 36 sites, ground-water discharge at 6 sites, ground-water quality at 19 sites, and ground-water withdrawals within Crater Flat, Jackass Flats, Mercury Valley, and the Amargosa Desert are presented. Data on ground-water levels, discharges, and withdrawals collected by other agencies (or as part of other programs) are included to further indicate variations through time at selected monitoring locations. Data are included in this report from 1910 through 1992.

  18. Summary of lithologic logging of new and existing boreholes at Yucca Mountain, Nevada, August 1993 to February 1994

    SciTech Connect

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

    1995-05-01

    Yucca Mountain, Nevada, is being investigated as a potential site for a high-level radioactive waste repository. This report summarizes the lithologic logging of new and existing boreholes at Yucca Mountain that was done from August 1993 to February 1994 by the Rock Characteristics Section, Yucca Mountain Project Branch, US Geological Survey (USGS). Units encountered during logging include Quaternary-Tertiary alluvium/colluvium, Tertiary Rainier Mesa Tuff, all units in the Tertiary Paintbrush Group, Tertiary Calico Hills Formation and Tertiary Prow Pass Tuff. We present criteria used for recognition of stratigraphic contacts, logging results as tables of contact depths for core from neutron (UZN) boreholes and graphical lithologic logs for core from non-UZN boreholes, and descriptions of several distinctive nonwelded tuffs recognized in the PTn hydrogeologic unit of the Paintbrush Group.

  19. The Sorption/Desorption Behavior of Uranium in Transport Studies Using Yucca Mountain Alluvium

    SciTech Connect

    C. D. Scism

    2006-02-15

    Yucca Mountain, Nevada is the proposed site of a geologic repository for the disposal of spent nuclear fuel and high-level radioactive waste in the United States. In the event repository engineered barriers fail, the saturated alluvium located south of Yucca Mountain is expected to serve as a natural barrier to the migration of radionuclides to the accessible environment. The purpose of this study is to improve the characterization of uranium retardation in the saturated zone at Yucca Mountain to support refinement of an assessment model. The distribution of uranium desorption rates from alluvium obtained from Nye County bore holes EWDP-19IM1, EWDP-10SA, EWDP-22SA were studied to address inconsistencies between results from batch sorption and column transport experiments. The alluvium and groundwater were characterized to better understand the underlying mechanisms of the observed behavior. Desorption rate constants were obtained using an activity based mass balance equation and column desorption experiments were analyzed using a mathematical model utilizing multiple sorption sites with different first-order forward and reverse reaction rates. The uranium desorption rate constants decreased over time, suggesting that the alluvium has multiple types of active sorption sites with different affinities for uranium. While a significant fraction of the initially sorbed uranium desorbed from the alluvium quite rapidly, a roughly equivalent amount remained sorbed after several months of testing. The information obtained through this research suggests that uranium may experience greater effective retardation in the alluvium than simple batch sorption experiments would suggest. Electron Probe Microanalysis shows that uranium is associated with both clay minerals and iron oxides after sorption to alluvial material. These results provide further evidence that the alluvium contains multiple sorption sites for uranium.

  20. Multiple-point statistical prediction on fracture networks at Yucca Mountain

    SciTech Connect

    Liu, X.Y; Zhang, C.Y.; Liu, Q.S.; Birkholzer, J.T.

    2009-05-01

    In many underground nuclear waste repository systems, such as at Yucca Mountain, water flow rate and amount of water seepage into the waste emplacement drifts are mainly determined by hydrological properties of fracture network in the surrounding rock mass. Natural fracture network system is not easy to describe, especially with respect to its connectivity which is critically important for simulating the water flow field. In this paper, we introduced a new method for fracture network description and prediction, termed multi-point-statistics (MPS). The process of the MPS method is to record multiple-point statistics concerning the connectivity patterns of a fracture network from a known fracture map, and to reproduce multiple-scale training fracture patterns in a stochastic manner, implicitly and directly. It is applied to fracture data to study flow field behavior at the Yucca Mountain waste repository system. First, the MPS method is used to create a fracture network with an original fracture training image from Yucca Mountain dataset. After we adopt a harmonic and arithmetic average method to upscale the permeability to a coarse grid, THM simulation is carried out to study near-field water flow in the surrounding waste emplacement drifts. Our study shows that connectivity or patterns of fracture networks can be grasped and reconstructed by MPS methods. In theory, it will lead to better prediction of fracture system characteristics and flow behavior. Meanwhile, we can obtain variance from flow field, which gives us a way to quantify model uncertainty even in complicated coupled THM simulations. It indicates that MPS can potentially characterize and reconstruct natural fracture networks in a fractured rock mass with advantages of quantifying connectivity of fracture system and its simulation uncertainty simultaneously.

  1. Origins of secondary silica within Yucca Mountain, Nye County, southwestern Nevada

    SciTech Connect

    Moscati, R.J.; Whelan, J.F.

    1996-09-01

    The accuracy of predictions of the hydrologic response of Yucca Mountain to future climate depends largely on how well relations between past climate and hydrology can be resolved. To advance this reconstruction, secondary minerals in and near Yucca Mountain, deposited by ground waters that originated both as surficial recharge at Yucca Mountain and from regional aquifers, are being studied to determine past ground-water sources and chemistries. Preliminary data on stable oxygen isotopes indicate that, although silica (opal, quartz, and chalcedony) and calcite and have formed in similar settings and from somewhat similar fluids, the authors have found no compelling evidence of coprecipitation or formation from identical fluids. If verified by further analyses, this precludes the use of silica-calcite mineral pairs for precise geothermometry. The preliminary data also indicate that opal and calcite occurrences in pedogenic and unsaturated-zone settings are invariably compatible with formation under modern ambient surface or subsurface temperatures. Silica and calcite stable-isotope studies are being integrated with soil geochemical modeling. This modeling will define the soil geochemical condition (climate) leading to opal or calcite deposition and to the transfer functions that may apply at the meteorologic soil unsaturated-zone interfaces. Additional study of pedogenic and unsaturated-zone silica is needed to support these models. The hypothesis that the transformation of vapor-phase tridymite to quartz requires saturated conditions is being tested through stable oxygen-isotope studies of lithophysal tridymite/quartz mixtures. Should this hypothesis be verified, mineralogic analysis by X-ray diffraction theoretically would permit reconstruction of past maximum water-table elevations.

  2. Fracture characterization of the large-block test, Fran Ridge, Yucca Mountain, Nevada

    SciTech Connect

    Wagoner, J.L.

    1999-04-28

    The US Department of Energy (DOE) is investigating the suitability of Yucca Mountain as a potential site for the nation's first high-level nuclear waste repository. The site is located about 120 km northwest of Las Vegas, Nevada, at the Nevada Test Site. Favorable aspects of Yucca Mountain as a potential repository site include its arid nature and the sorptive properties of the rock materials. The arid environment results in unsaturated conditions at the potential emplacement horizon, which is the Topopah Spring tuff of the Paintbrush Group. The Large Block Test (LBT) was designed to be one of a series of tests at different scales and conditions that assist in defining the physical processes that need to be considered in models of a potential repository in Yucca Mountain. The LBT is a critical test because it is of sufficient size to incorporate a fracture system that is representative of the distribution of fracture dimensions and characteristics--with the exception of major structures, such as faults--that would likely be present in a repository. The LBT location was chosen to include large, through-going fractures as well as small, healed fractures that are of limited extent. The LBT location also includes a variety of fracture sizes, connectivities, and characteristics that fall between the bounds of the large and very small fractures. The LBT allows for boundary controls and monitoring that are somewhat similar to those typical of laboratory studies, and it allows for three-dimensional (3-D) characterization and monitoring. The unique combination of size with boundary controls of the LBT allows processes to be evaluated and models to be tested more completely than in tests of any other scale (Wilder et al. 1997, Section 1).

  3. Existing Evidence for the Fate of Neptunium in the Yucca Mountain Repository

    SciTech Connect

    Friese, Judah I. ); Buck, Edgar C. ); McNamara, Bruce K. ); Hanson, Brady D. ); Marschman, Steven C. )

    2003-06-18

    Neptunium, because of its long half life, is an element of long-term interest to the Yucca Mountain repository. The fate of neptunium under repository settings is unknown. This report provides a review and new interpretation of past tests on commercial spent nuclear fuel and experimental evidence on the fate of neptunium. Tests on commercial spent nuclear fuel preformed previously at Pacific Northwest National Laboratory (PNNL) used a bathtub setup by immersing spent fuel in either deionized water or a groundwater typical of those at Yucca Mountain. The main goal of the tests was to determine the different concentrations of radionuclides in solution with different types of cladding defects. Neptunium was not the focus of these tests, nor were the tests designed to study neptunium. Drip tests performed at Argonne National Laboratory (ANL) are unsaturated tests that drip water at different rates on spent fuel. Relatively new tests at ANL examine the corrosion of Np-doped U3O8 in humid air at various temperatures. This review concludes that all tests reported here have analytical problems (i.e., relatively high detection limits for Np) and have been configured such that they limit the ability to interpret the available neptunium data. Past tests on spent nuclear fuel do not unambiguously describe neptunium chemistry as there are multiple mechanisms that may explain the observed behavior in each test. One apparently major shortcoming of most tests is that the extent of fuel reaction was limited by the amount of oxygen present in the system. Further detailed studies under repository-relevant conditions, which include the assumption of a constant 20 percent oxygen atmosphere, are needed to provide the data necessary for the development and validation of models used to predict the long-term fate of neptunium and other radionuclides at Yucca Mountain.

  4. Multiple-point statistical prediction on fracture networks at Yucca Mountain

    NASA Astrophysics Data System (ADS)

    Liu, Xiaoyan; Zhang, Chengyuan; Liu, Quansheng; Birkholzer, Jens

    2009-05-01

    In many underground nuclear waste repository systems, such as Yucca Mountain project, water flow rate and amount of water seepage into the waste emplacement drifts are mainly determined by hydrological properties of fracture network in the surrounding rock mass. Natural fracture network system is not easy to describe, especially with respect to its connectivity which is critically important for simulating the water flow field. In this paper, we introduced a new method for fracture network description and prediction, termed multi-point-statistics (MPS). The process of Multi-point Statistical method is to record multiple-point statistics concerning the connectivity patterns of fracture network from a known fracture map, and to reproduce multiple-scale training fracture patterns in a stochastic manner, implicitly and directly. It is applied to fracture data to study flow field behavior at Yucca Mountain waste repository system. First, MPS method is used to create fracture network with original fracture training image from Yucca Mountain dataset. After we adopt a harmonic and arithmetic average method to upscale the permeability to a coarse grid, THM simulation is carried out to study near-field water flow in surrounding rock of waste emplacement drifts. Our study shows that connectivity or pattern of fracture network can be grasped and reconstructed by Multi-Point-Statistical method. In theory, it will lead to better prediction of fracture system characteristics and flow behavior. Meanwhile, we can obtain variance from flow field, which gives us a way to quantify uncertainty of models even in complicated coupled THM simulation. It indicates that Multi-Point Statistics is a potential method to characterize and reconstruct natural fracture network in a fractured rock mass with advantages of quantifying connectivity of fracture system and its simulation uncertainty simultaneously.

  5. The Yucca Mountain Project prototype air-coring test, U12g tunnel, Nevada test site

    SciTech Connect

    Ray, J.M.; Newsom, J.C.

    1994-12-01

    The Prototype Air-Coring Test was conducted at the Nevada Test Site (NTS) G-Tunnel facility to evaluate standard coring techniques, modified slightly for air circulation, for use in testing at a prospective nuclear waste repository at Yucca Mountain, Nevada. Air-coring technology allows sampling of subsurface lithology with minimal perturbation to ambient characteristic such as that required for exploratory holes near aquifers, environmental applications, and site characterization work. Two horizontal holes were cored, one 50 ft long and the other 150 ft long, in densely welded fractured tuff to simulate the difficult drilling conditions anticipated at Yucca Mountain. Drilling data from seven holes on three other prototype tests in nonwelded tuff were also collected for comparison. The test was used to establish preliminary standards of performance for drilling and dust collection equipment and to assess procedural efficiencies. The Longyear-38 drill achieved 97% recovery for HQ-size core (-2.5 in.), and the Atlas Copco dust collector (DCT-90) captured 1500 lb of fugitive dust in a mine environment with only minor modifications. Average hole production rates were 6-8 ft per 6-h shift in welded tuff and almost 20 ft per shift on deeper holes in nonwelded tuff. Lexan liners were successfully used to encapsulate core samples during the coring process and protect core properties effectively. The Prototype Air-Coring Test demonstrated that horizontal air coring in fractured welded tuff (to at least 150 ft) can be safely accomplished by proper selection, integration, and minor modification of standard drilling equipment, using appropriate procedures and engineering controls. The test also indicated that rig logistics, equipment, and methods need improvement before attempting a large-scale dry drilling program at Yucca Mountain.

  6. Fault Block Deformation Resulting From Fault Displacement Gradients at Yucca Mountain, Nevada

    NASA Astrophysics Data System (ADS)

    Morris, A. P.; Ferrill, D. A.; Franklin, N.; Sims, D. W.; Waiting, D. J.; Stamatakos, J. A.

    2001-12-01

    Displacement gradients on normal faults generate cutoff-line-parallel length changes. Yucca Mountain, Nevada is cut by numerous NS trending normal faults that exhibit steep displacement gradients. We apply a new method for quantifying the strain that develops adjacent to faults as a result of displacement variations, to Yucca Mountain, Nevada. Using existing maps and the Department of Energy's 3D Geologic Framework Model as sources of high precision data we have analyzed the likely state of strain of the fault blocks in Yucca Mountain. The results indicate that the strain is sensitive to the ambient stress field and the resultant slip directions at the time of fault formation, and to the orientation of the principal rock units prior to faulting. Assuming that at the time of faulting the volcanic tuffs were horizontal, and the stress field was conducive to EW-directed extension, zones of potentially high strain are identified. At least three of these are zones of intense deformation: the West Ridge connecting fault system between the Northern Windy Wash and Fatigue Wash faults, the ridges between Solitario Canyon and Fatigue Wash, and the fault block between the Iron Ridge and Solitario Canyon faults. This approach is being used to assess the intensity of deformation within fault blocks that are considered part of the Department of Energy's extended definition of blocks suitable for the U.S.A.'s potential high level nuclear waste repository. Work supported by the U.S. NRC (contract NRC-02-97-009) This work is an independent product of the CNWRA and does not necessarily represent the regulatory position of the NRC.

  7. Evaluation of habitat restoration needs at Yucca Mountain, Nevada Test Site, Nye County, Nevada

    SciTech Connect

    Mitchell, D.L.

    1984-04-01

    Adverse environmental impacts due to site characterization and repository development activities at Yucca Mountain, Nevada Test Site (NTS), Nye County, Nevada, must be minimized and mitigated according to provisions of the Nuclear Waste Policy Act (NWPA) of 1982 and the National Environmental Policy Act (NEPA). The natural Transition Desert ecosystem in the 27.5-sq-mi Yucca Mountain project area is now and will continue to be impacted by removal of native vegetation and topsoil and the destruction and/or displacement of faunal communities. Although it is not known at this time exactly how much land will be affected, it is estimated that about 300 to 400 acres will be disturbed by construction of facility sites, mining spoils piles, roadways, and drilling pads. Planned habitat restoration at Yucca Mountain will mitigate the effects of plant and animal habitat loss over time by increasing the rate of plant succession on disturbed sites. Restoration program elements should combine the appropriate use of native annual and perennial species, irrigation and/or water-harvesting techniques, and salvage and reuse of topsoil. Although general techniques are well-known, specific program details (i.e., which species to use, methods of site preparation with available equipment, methods of saving and applying topsoil, etc.) must be worked out empirically on a site-specific basis over the period of site characterization and any subsequent repository development. Large-scale demonstration areas set up during site characterization will benefit both present abandonments and, if the project is scaled up to include repository development, larger facilities areas including spoils piles. Site-specific demonstration studies will also provide information on the costs per acre associated with alternative restoration strategies.

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

    SciTech Connect

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

    1982-12-31

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

  9. Physical processes and effects of magmatism in the Yucca Mountain region

    SciTech Connect

    Valentine, G.A.; Crowe, B.M.; Perry, F.V.

    1991-12-31

    This paper describes initial studies related to the effects of volcanism on performance of the proposed Yucca Mountain radioactive waste repository, and to the general processes of magmatism in the Yucca Mountain region. Volcanism or igneous activity can affect the repository performance by ejection of waste onto the earth`s surface (eruptive effects), or by subsurface effects of hydrothermal processes and altered hydrology if an intrusion occurs within the repository block. Initial, conservative calculations of the volume of waste that might be erupted during a small-volume basaltic eruption (such as those which occurred in the Yucca Mountain region) indicate that regulatory limits might be exceeded. Current efforts to refine these calculations, based upon field studies at analog sites, are described. Studies of subsurface effects are just beginning, and are currently focused on field studies of intrusion properties and contact metamorphism at deeply eroded analog sites. General processes of magmatism are important for providing a physical basis for predictions of future volcanic activity. Initial studies have focused on modeling basaltic magma chambers in conjunction with petrographic and geochemical studies. An example of the thermal-fluid dynamic evolution of a small basaltic sill is described, based on numerical simulation. Quantification of eruption conditions can provide valuable information on the overall magmatic system. We are developing quantitative methods for mapping pyroclastic facies of small basaltic centers and, in combination with two-phase hydrodynamic simulation, using this information to estimate eruption conditions. Examples of such hydrodynamic simulations are presented, along with comparison to an historical eruption in Hawaii.

  10. Status of volcanism studies for the Yucca Mountain Site Characterization Project

    SciTech Connect

    Crowe, B.; Perry, F.; Murrell, M.; Poths, J.; Valentine, G.A.; Wells, S.; Bowker, L.; Finnegan, K.; Geissman, J.; McFadden, L.

    1995-02-01

    Chapter 1 introduces the volcanism issue for the Yucca Mountain site and provides the reader with an overview of the organization, content, and significant conclusions of this report. The risk of future basaltic volcanism is the primary topic of concern including both events that intersect a potential repository and events that occur near or within the waste isolation system of a repository. Chapter 2 describes the volcanic history of the Yucca Mountain region (YMR) and emphasizes the Pliocene and Quaternary volcanic record, the interval of primary concern for volcanic risk assessment. The Lathrop Wells volcanic center is described in detail because it is the youngest basalt center in the YMR. Chapter 3 describes the tectonic setting of the YMR and presents and assesses the significance of multiple alternative tectonic models. Geophysical data are described for the YMR and are used as an aid to understand the distribution of basaltic volcanic centers. Chapter 4 discusses the petrologic and geochemical features of basaltic volcanism in the YMR, the southern Great Basin and the Basin and Range province. The long time of activity and characteristic small volume of the Postcaldera basalt of the YMR result in one of the lowest eruptive rates in a volcanic field in the southwest United States. Chapter 5 summarizes current concepts of the segregation, ascent, and eruption of basalt magma. Chapter 6 summarizes the history of volcanism studies (1979 through early 1994), including work for the Yucca Mountain Site Characterization Project and overview studies by the state of Nevada and the Nuclear Regulatory Commission. Chapter 7 summarizes probabilistic volcanic hazard assessment using a three-part conditional probability model. Chapter 8 describes remaining volcanism work judged to be needed to complete characterization studies for the YMR. Chapter 9 summarizes the conclusions of this volcanism status report.

  11. A Summary of Properties Used to Evaluate INEEL Calcine Disposal in the Yucca Mountain Repository

    SciTech Connect

    Dahl, C.A.

    2003-07-14

    To support evaluations of the direct disposal of Idaho National Engineering and Environmental Laboratory calcines to the repository at Yucca Mountain, an evaluation of the performance of the calcine in the repository environment must be performed. This type of evaluation demonstrates, through computer modeling and analysis, the impact the calcine would have on the ability of the repository to perform its function of containment of materials during the repository lifetime. This report discusses parameters that were used in the scoping evaluation conducted in FY 2003. It provides nominal values for the parameters, with explanation of the source of the values, and how the values were modified for use in repository analysis activities.

  12. Alternative Igneous Source Term Model for Tephra Dispersal at the Yucca Mountain Repository

    SciTech Connect

    Codell, Richard Blake

    2004-11-15

    The Nuclear Regulatory Commission uses the ASHPLUME model in its evaluation of the basaltic volcanism scenario at the possible Yucca Mountain repository. The mixing of magma with the spent-fuel waste form is tied to a reasonable but unverified model that predicts that no dense tephra/fuel particles would form. An alternative model uses a mixing rule that allows the formation of dense tephra/fuel particles that would be transported in the volcanic plume differently. The alternative model shows significant sensitivity to the spent-fuel particle size distribution. However, differences in results between the two models are on average less than a factor of 2.

  13. 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.

  14. Engineered barrier system and waste package design concepts for a potential geologic repository at Yucca Mountain

    SciTech Connect

    Short, D.W.; Ruffner, D.J.; Jardine, L.J.

    1991-10-01

    We are using an iterative process to develop preliminary concept descriptions for the Engineered Barrier System and waste-package components for the potential geologic repository at Yucca Mountain. The process allows multiple design concepts to be developed subject to major constraints, requirements, and assumptions. Involved in the highly interactive and interdependent steps of the process are technical specialists in engineering, metallic and nonmetallic materials, chemistry, geomechanics, hydrology, and geochemistry. We have developed preliminary design concepts that satisfy both technical and nontechnical (e.g., programmatic or policy) requirements.

  15. TOSPAC calculations in support of the COVE 2A benchmarking activity; Yucca Mountain Site Characterization Project

    SciTech Connect

    Gauthier, J.H.; Zieman, N.B.; Miller, W.B.

    1991-10-01

    The purpose of the the Code Verification (COVE) 2A benchmarking activity is to assess the numerical accuracy of several computer programs for the Yucca Mountain Site Characterization Project of the Department of Energy. This paper presents a brief description of the computer program TOSPAC and a discussion of the calculational effort and results generated by TOSPAC for the COVE 2A problem set. The calculations were performed twice. The initial calculations provided preliminary results for comparison with the results from other COVE 2A participants. TOSPAC was modified in response to the comparison and the final calculations included a correction and several enhancements to improve efficiency. 8 refs.

  16. The Integration and Abstracyion of EBS Models in Yucca Mountain Performance Assessment

    SciTech Connect

    S.D. Sevougian; V. Jain; A.V. Luik

    2006-01-11

    The safety strategy for geological disposal of radioactive waste at Yucca Mountain relies on a multi-barrier system to contain the waste and isolate it from the biosphere. The multi-barrier system consists of the natural barrier provided by the geological setting and the engineered barrier system (EBS). In the case of Yucca Mountain (YM) the geologic setting is the unsaturated-zone host rock, consisting of about 600 meters of layered ash-flow volcanic tuffs above the water table, and the saturated zone beneath the water table. Both the unsaturated and saturated rocks are part of a closed hydrologic basin in a desert surface environment. The waste is to be buried about halfway between the desert surface and the water table. The primary engineered barriers at YM consist of metal components that are highly durable in an oxidizing environment. The two primary components of the engineered barrier system are highly corrosion-resistant metal waste packages, made from a nickel-chromium-molybdenum alloy, Alloy 22, and titanium drip shields that protect the waste packages from corrosive dripping water and falling rocks. Design and performance assessment of the EBS requires models that describe how the EBS and near field behave under anticipated repository-relevant conditions. These models must describe coupled hydrologic, thermal, chemical, and mechanical (THCM) processes that drive radionuclide transport in a highly fractured host rock, consisting of a relatively permeable network of conductive fractures in a setting of highly impermeable tuff rock matrix. An integrated performance assessment of the EBS must include a quantification of the uncertainties that arise from (1) incomplete understanding of processes and (2) from lack of data representative of the large spatial scales and long time scales relevant to radioactive waste disposal (e.g., long-term metal corrosion rates and heterogeneities in rock properties over the large 5 km{sup 2} emplacement area of the repository

  17. Site characterization progress report: Yucca Mountain, Nevada, October 1, 1990--March 31, 1991; Number 4

    SciTech Connect

    1991-10-01

    In accordance with the requirements of Section 113 (b) (3) of the Nuclear Waste Policy Act of 1982, as amended (NWPA), the US Department of Energy (DOE) has prepared this report on the progress of site characterization activities at Yucca Mountain, Nevada, for the period October 1, 1990, through March 31, 1991. This report is the fourth in a series of reports that are issued at intervals of approximately six months during site characterization. The report covers a number of initiatives to improve the effectiveness of the site characterization program, and covers continued efforts related to preparatory activities, Study Plans, and performance assessment.

  18. Multiphysics processes in partially saturated fractured rock: Experiments and models from Yucca Mountain

    NASA Astrophysics Data System (ADS)

    Rutqvist, Jonny; Tsang, Chin-Fu

    2012-09-01

    The site investigations at Yucca Mountain, Nevada, have provided us with an outstanding data set, one that has significantly advanced our knowledge of multiphysics processes in partially saturated fractured geological media. Such advancement was made possible, foremost, by substantial investments in multiyear field experiments that enabled the study of thermally driven multiphysics and testing of numerical models at a large spatial scale. The development of coupled-process models within the project have resulted in a number of new, advanced multiphysics numerical models that are today applied over a wide range of geoscientific research and geoengineering applications. Using such models, the potential impact of thermal-hydrological-mechanical (THM) multiphysics processes over the long-term (e.g., 10,000 years) could be predicted and bounded with some degree of confidence. The fact that the rock mass at Yucca Mountain is intensively fractured enabled continuum models to be used, although discontinuum models were also applied and are better suited for analyzing some issues, especially those related to predictions of rockfall within open excavations. The work showed that in situ tests (rather than small-scale laboratory experiments alone) are essential for determining appropriate input parameters for multiphysics models of fractured rocks, especially related to parameters defining how permeability might evolve under changing stress and temperature. A significant laboratory test program at Yucca Mountain also made important contributions to the field of rock mechanics, showing a unique relation between porosity and mechanical properties, a time dependency of strength that is significant for long-term excavation stability, a decreasing rock strength with sample size using very large core experiments, and a strong temperature dependency of the thermal expansion coefficient for temperatures up to 200°C. The analysis of in situ heater experiments showed that fracture

  19. A FRAMEWORK FOR THE ANALYSIS OF LOCALIZED CORROSION AT THE PROPOSED YUCCA MOUNTAIN REPOSITORY

    SciTech Connect

    Dr. J.H. Payer

    2006-04-18

    Corrosion is a primary determinant of waste package performance at the proposed Yucca Mountain Repository: (1) the most likely degradation process; (2) controls the delay time for radionuclide transport from the waste package; and (3) determines when packages will be penetrated and the shape size and distribution of those penetrations. In this presentation a framework for the analysis of localized corrosion is presented and demonstrated for a scenario: (1) water chemistry of mixed salt solutions (sodium chloride-potassium nitrate); and (2) time-temperature-relative humidity profiles for a hot, mid and cool temperature waste package.

  20. Cost-Effective Cementitious Material Compatible with Yucca Mountain Repository Geochemistry

    SciTech Connect

    Dole, LR

    2004-12-17

    The current plans for the Yucca Mountain (YM) repository project (YMP) use steel structures to stabilize the disposal drifts and connecting tunnels that are collectively over 100 kilometers in length. The potential exist to reduce the underground construction cost by 100s of millions of dollars and improve the repository's performance. These economic and engineering goals can be achieved by using the appropriate cementitious materials to build out these tunnels. This report describes the required properties of YM compatible cements and reviews the literature that proves the efficacy of this approach. This report also describes a comprehensive program to develop and test materials for a suite of underground construction technologies.

  1. Fabrication and closure development of nuclear waste disposal containers for the Yucca Mountain Project: Status report

    SciTech Connect

    Domian, H.A.; Robitz, E.S.; Conrardy, C.C.; LaCount, D.F.; McAninch, M.D.; Fish, R.L.; Russell, E.W.

    1991-09-01

    In GFY 89, a project was underway to determine and demonstrate a suitable method for fabricating thin-walled monolithic waste containers for service within the potential repository at Yucca Mountain. A concurrent project was underway to determine and demonstrate a suitable closure process for these containers after they have been filled with high-level nuclear waste. Phase 1 for both the fabrication and closure projects was a screening phase in which candidate processes were selected for further laboratory testing in Phase 2. This report describes the final results of the Phase 1 efforts. It also describes the preliminary results of Phase 2 efforts.

  2. 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.

  3. Frictional sliding in layered rock model: Preliminary experiments. Yucca Mountain Site Characterization Project

    SciTech Connect

    Perry, K.E. Jr.; Buescher, B.J.; Anderson, D.; Epstein, J.S.

    1995-09-01

    An important aspect of determining the suitability of Yucca Mountain as a possible nuclear waste repository requires understanding the mechanical behavior of jointed rock-masses. To this end we have studied the frictional sliding between simulated rock joints in the laboratory using the technique of phase shifting moire interferometry. The models were made from stacks of Lexan plates and contained a central hole to induce slip between the plates when the models were loaded in compression. These preliminary results confirm the feasibility of the approach and show a clear evolution of slip as function of load.

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

    SciTech Connect

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

    1982-12-31

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

  5. Geochemistry of Natural Components in the Near-Field Environment, Yucca Mountain, Nevada

    SciTech Connect

    Peterman, Zell E.; Oliver, Thomas A.

    2007-07-01

    The natural near-field environment in and around the emplacement drifts of the proposed nuclear waste repository at Yucca Mountain, Nevada, includes the host rock, dust, seepage, and pore water. The chemical compositions of these components have been determined for assessing possible chemical and mineralogical reactions that may occur after nuclear waste is emplaced. The rock hosting the proposed repository is relatively uniform as shown by a mean coefficient of variation (CV) of 9 percent for major elements. In contrast, compositional variations of dust (bulk and water-soluble fractions), pore water, and seepage are large with mean CVs ranging from 28 to 64 percent. (authors)

  6. Geochemistry of natural components in the near-field environment, Yucca Mountain, Nevada

    USGS Publications Warehouse

    Peterman, Z.E.; Oliver, T.A.

    2007-01-01

    The natural near-field environment in and around the emplacement drifts of the proposed nuclear waste repository at Yucca Mountain, Nevada, includes the host rock, dust, seepage, and pore water. The chemical compositions of these components have been determined for assessing possible chemical and mineralogical reactions that may occur after nuclear waste is emplaced. The rock hosting the proposed repository is relatively uniform as shown by a mean coefficient of variation (CV) of 9 percent for major elements. In contrast, compositional variations of dust (bulk and water-soluble fractions), pore water, and seepage are large with mean CVs ranging from 28 to 64 percent. ?? 2007 Materials Research Society.

  7. Role of underground testing to determine suitability of Yucca Mountain as a potential repository site

    SciTech Connect

    Kalia, H.N.

    1990-02-01

    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.

  8. Two-dimensional numerical simulation of geochemical transport in Yucca Mountain

    SciTech Connect

    Travis, B.J.; Nuttall, H.E.

    1987-12-01

    Several physical and chemical processes can affect transport of radionuclides in Yucca Mountain. Geometric spreading and lateral flow will reduce the concentration of contaminated water reaching the accessible environment. Travel times to the water table are calculated to be at least several tens of thousands of years. Colloid transport can also enhance radionuclide transport, but will be important only if fracture flow is. Finally, the heat load from repository waste can alter the distribution of some naturally occurring minerals. In particular, dissolution and precipitation of SiO{sub 2} should lead to a region of reduced permeability around waste canisters. 22 refs., 47 figs., 7 tabs.

  9. User`s guide to the Yucca Mountain Integrating Model (YMIM) Version 2.1

    SciTech Connect

    Gansemer, J.; Lamont, A.

    1995-04-01

    The Yucca Mountain Integrating Model (YMIM) is an integrated model of the engineered barrier system. It contains models of the processes of waste container failure and nuclide release from the fuel rods. YMIM is driven by scenarios of container and rod temperature, near-field chemistry, and near-field hydrology provided by other modules. It is designed to be highly modular so that a model of an individual process can be easily modified to replaced without interfering with the models of other processes. This manual describes the process models and provides instructions for setting up and running YMIM Version 2.1.

  10. Hydrologic and geologic characteristics of the Yucca Mountain site relevant to the performance of a potential repository

    USGS Publications Warehouse

    Levich, R.A.; Linden, R.M.; Patterson, R.L.; Stuckless, J.S.

    2000-01-01

    Yucca Mountain, located ~100 mi northwest of Las Vegas, Nevada, has been designated by Congress as a site to be characterized for a potential mined geologic repository for high-level radioactive waste. This field trip will examine the regional geologic and hydrologic setting for Yucca Mountain, as well as specific results of the site characterization program. The first day focuses on the regional setting with emphasis on current and paleo hydrology, which are both of critical concern for predicting future performance of a potential repository. Morning stops will be southern Nevada and afternoon stops will be in Death Valley. The second day will be spent at Yucca Mountain. The field trip will visit the underground testing sites in the "Exploratory Studies Facility" and the "Busted Butte Unsaturated Zone Transport Field Test" plus several surface-based testing sites. Much of the work at the site has concentrated on studies of the unsaturated zone, an element of the hydrologic system that historically has received little attention. Discussions during the second day will compromise selected topics of Yucca Mountain geology, hydrology and geochemistry and will include the probabilistic volcanic hazard analysis and the seismicity and seismic hazard in the Yucca Mountain area. Evening discussions will address modeling of regional groundwater flow, the results of recent hydrologic studies by the Nye County Nuclear Waste Program Office, and the relationship of the geology and hydrology of Yucca Mountain to the performance of a potential repository. Day 3 will examine the geologic framework and hydrology of the Pahute Mesa-Oasis Valley Groundwater Basin and then will continue to Reno via Hawthorne, Nevada and the Walker Lake area.

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

    SciTech Connect

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

    1996-12-31

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

  12. Fluid flow and reactive transport around potential nuclear waste emplacement tunnels at Yucca Mountain, Nevada

    SciTech Connect

    Spycher, N.F.; Sonnenthal, E.L.; Apps, J.A.

    2002-09-01

    small relative to the mode l uncertainty and the variability of water compositions at Yucca Mountain.

  13. Fluid flow and reactive transport around potential nuclear waste emplacement tunnels at Yucca Mountain, Nevada.

    PubMed

    Spycher, N F; Sonnenthal, E L; Apps, J A

    2003-01-01

    the model uncertainty and the variability of water compositions at Yucca Mountain. PMID:12714315

  14. Fluid flow and reactive transport around potential nuclear waste emplacement tunnels at Yucca Mountain, Nevada

    NASA Astrophysics Data System (ADS)

    Spycher, N. F.; Sonnenthal, E. L.; Apps, J. A.

    2003-05-01

    model uncertainty and the variability of water compositions at Yucca Mountain.

  15. Preliminary U-series disequilibrium and thermoluminescence ages of surficial deposits and paleosols associated with Quaternary faults, eastern Yucca Mountain

    SciTech Connect

    Paces, J.B.; Menges, C.M.; Bush, C.A.; Futa, K.; Millard, H.T.; Maat, P.B.; Whitney, J.W.; Widmann, B.; Wesling, J.R.

    1994-12-31

    Geochronological control is an essential component of paleoseismic evaluation of faults in the Yucca Mountain region. New U-series disequilibrium and thermoluminescence age estimates for pedogenic deposits that bracket surface-rupture events are presented from four sites exposing the Paintbrush Canyon, Bow Ridge and Stagecoach Road faults. Ages show an internal consistency with stratigraphic relationships as well as an overall concordancy between the two independent geochronometers. Age estimates are therefore interpreted to date depositional events or episodes of pedogenic carbonate mobility that can be used to establish a paleoseismic fault chronology. Ultimately, this type of chronological information will be used to evaluate seismic hazards at Yucca Mountain.

  16. Preliminary U-series disequilibrium and thermoluminescence ages of surficial deposits and paleosols associated with Quaternary fault, Eastern Yucca Mountain

    SciTech Connect

    Paces, J.B.; Menges, C.M.; Bush, C.A.; Futa, K.; Millard, H.T.; Maat, P.B.; Whitney, J.W.; Widmann, B.; Wesling, J.R.

    1994-12-31

    Geochronological control is an essential component of paleoseismic evaluation of faults in the Yucca Mountain region. New U-series disequilibrium and thermoluminescence age estimates for pedogenic deposits that bracket surface-rupture events are presented from four sites exposing the Paintbrush Canyon, Bow Ridge and Stagecoach Road faults. Ages show an internal consistency with stratigraphic relationships as well as an overall concordancy between the two independent geochronometers. Age estimates are therefore interpreted to date depositional events or episodes of pedogenic carbonate mobility that can be used to establish a paleoseismic fault chronology. Ultimately, this type of chronological information will be used to evaluate seismic hazards at Yucca Mountain.

  17. Uranium-series dating of secondary carbonates near Yucca Mountain, Nevada; Applications to tectonic, paleoclimatic and paleohydrologic problems

    SciTech Connect

    Muhs, D.R.; Whitney, J.W.; Shroba, R.R.; Taylor, E.M.; Bush, C.A.

    1990-10-01

    This paper discusses near-surface accumulations of secondary carbonates common in the soils and sediments of the Yucca Mountain area. These carbonates contain small amounts of uranium that allow dating by the uranium-series disequilibrium method. The authors report that preliminary results from the Yucca Mountain area indicate that the U-series methods can identify multiple episodes of tectonic fracturing, provide a chronologic framework for paleoclimatically significant eolian deposits, and place constraints on the probable source of waters from which the carbonates precipitated.

  18. Investigations of hydro-tectonic hazards at the proposed Yucca Mountain high-level nuclear waste repository. Annual report - Nevada

    SciTech Connect

    Livingston, D.E.

    1994-01-01

    This document includes several reports describing scientific studies of the origin of near surface calcite/silica deposits at Yucca Mountain, Nevada. 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. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  19. Geothermal evaluation and analysis of the Yucca Mountain Repository, Nevada; Final report, July 1, 1989--December 31, 1989

    SciTech Connect

    1989-06-17

    This is the final report on the geothermal analysis and evaluation for the proposed nuclear waste repository at Yucca Mountain, for the period of July 1, 1989 to December 31, 1989. Heat flow values were derived by measuring the thermal conductivities of samples taken from selected exploratory wells. Temperature gradients are recorded from the same wells. By using computer generated contour maps of the area, another interpretation of the heat-flow can be derived. Results of the mapping do not coincide with the past observations of the data. Another method used to evaluate the heat-flow of Yucca Mountain was to compare the temperature-depth relationship of the area. (MB)

  20. Development and testing of techniques to obtain infiltration data for unconsolidated surficial materials, Yucca Mountain area, Nye County, Nevada

    SciTech Connect

    Hofmann, Lon L.; Guertal, William R.; Flint, Alan L.

    2000-12-31

    Measurements of surface infiltration at Yucca Mountain, Nevada, a potential site for a high-level nuclear-waste repository, are needed to determine spatial variability of hydrologic properties for a wide variety of skeletal desert soils. This report describes and evaluates existing instruments and methods to measure infiltration capacities and their appropriateness for determining hydrologic properties on Yucca Mountain. The report also presents preliminary infiltration data and estimated measurements of saturated hydraulic conductivity and sorptivity and describes the methods used to collect the data.

  1. Faulting in the Yucca Mountain region: Critical review and analyses of tectonic data from the central Basin and Range

    SciTech Connect

    Ferrill, D.A.; Stirewalt, G.L.; Henderson, D.B.; Stamatakos, J.; Morris, A.P.; Spivey, K.H.; Wernicke, B.P.

    1996-03-01

    Yucca Mountain, Nevada, has been proposed as the potential site for a high-level waste (HLW) repository. The tectonic setting of Yucca Mountain presents several potential hazards for a proposed repository, such as potential for earthquake seismicity, fault disruption, basaltic volcanism, magma channeling along pre-existing faults, and faults and fractures that may serve as barriers or conduits for groundwater flow. Characterization of geologic structures and tectonic processes will be necessary to assess compliance with regulatory requirements for the proposed high level waste repository. In this report, we specifically investigate fault slip, seismicity, contemporary stain, and fault-slip potential in the Yucca Mountain region with regard to Key Technical Uncertainties outlined in the License Application Review Plan (Sections 3.2.1.5 through 3.2.1.9 and 3.2.2.8). These investigations center on (i) alternative methods of determining the slip history of the Bare Mountain Fault, (ii) cluster analysis of historic earthquakes, (iii) crustal strain determinations from Global Positioning System measurements, and (iv) three-dimensional slip-tendency analysis. The goal of this work is to assess uncertainties associated with neotectonic data sets critical to the Nuclear Regulatory Commission and the Center for Nuclear Waste Regulatory Analyses` ability to provide prelicensing guidance and perform license application review with respect to the proposed HLW repository at Yucca Mountain.

  2. Preliminary description of quaternary and late pliocene surficial deposits at Yucca Mountain and vicinity, Nye County, Nevada

    SciTech Connect

    Hoover, D.L.

    1989-11-01

    The Yucca Mountain area, in the south-central part of the Great Basin, is in the drainage basin of the Amargosa River. The mountain consists of several fault blocks of volcanic rocks that are typical of the Basin and Range province. Yucca Mountain is dissected by steep-sided valleys of consequent drainage systems that are tributary on the east side to Fortymile Wash and on the west side to an unnamed wash that drains Crater Flat. Most of the major washes near Yucca Mountain are not integrated with the Amargosa River, but have distributary channels on the piedmont above the river. Landforms in the Yucca Mountain area include rock pediments, ballenas, alluvial pediments, alluvial fans, stream terraces, and playas. Early Holocene and older alluvial fan deposits have been smoothed by pedimentation. The semiconical shape of alluvial fans is apparent at the junction of tributaries with major washes and where washes cross fault and terrace scarps. Playas are present in the eastern and southern ends of the Amargosa Desert. 39 refs., 9 figs., 1 tab.

  3. Coupled In-Rock and In-Drift Hydrothermal Model Stuudy For Yucca Mountain

    SciTech Connect

    G. Danko; J. Birkholzer; D. Bahrami

    2006-12-18

    A thermal-hydrologic-natural-ventilation model is configured for simulating temperature, humidity, and condensate distributions in the coupled domains of the in-drift airspace and the near-field rockmass in the proposed Yucca Mountain repository. The multi-physics problem is solved with MULTIFLUX in which a lumped-parameter computational fluid dynamics model is iterated with TOUGH2. The solution includes natural convection, conduction, and radiation for heat as well as moisture convection and diffusion for moisture transport with half waste package scale details in the drift, and mountain-scale heat and moisture transport in the porous and fractured rock-mass. The method provides fast convergence on a personal computer computational platform. Numerical examples and comparison with a TOUGH2 based, integrated model are presented.

  4. Multiscale Thermohydrologic Model Supporting the Total System Performance Assessment for the Proposed Repository at Yucca Mountain

    NASA Astrophysics Data System (ADS)

    Buscheck, T. A.; Sun, Y.; Hao, Y.; Duan, Y.; Ezzedine, S.; James, S. C.

    2007-12-01

    The MultiScale ThermoHydrologic Model (MSTHM) is used in the total system performance assessment (TSPA) for the proposed nuclear-waste repository at Yucca Mountain. The MSTHM uses the Nonisothermal Unsaturated Flow and Transport (NUFT) code to represent thermal-hydrologic (TH) processes occurring at scales from a few tens of centimeters around individual waste packages and emplacement drifts (tunnels) all the way to the kilometer scale for heat flow through the mountain. The MSTHM is used to predict the anticipated range of TH conditions within emplacement drifts and adjoining host rock. To be defensible, the range in predicted TH conditions must address the influence of the variability and uncertainty of engineered- and natural-system parameters that significantly influence those conditions. Parameter-sensitivity analyses show that the most important natural-system parameters are host-rock thermal conductivity and percolation flux through the repository. These analyses show that the key engineered-system parameter is the waste-package-to-waste- package variability in heat output. The range in TH conditions is also influenced by the "edge-cooling" effect, where waste packages closer to the repository edge cool more quickly than those closer to the repository center. To account for this effect, the MSTHM represents the geometric details of the repository layout. Improvements have also been made to how the MSTHM incorporates hydrostratigraphic and percolation-flux data from the Unsaturated Zone Flow Model, which supports ambient flow and transport simulations for TSPA. Other improvements allow more parameter sensitivity cases to be investigated. Twelve cases are analyzed, including four percolation-flux scenarios (10-, 30-, 50- and 90-percentile) and three host-rock thermal-conductivities (10- percentile, mean, and 90-percentile). Using the results of stochastic analyses, weighting factors are applied to the twelve cases. This work was performed under the auspices of

  5. Combined analysis of surface reflection imaging and vertical seismic profiling at Yucca Mountain, Nevada

    SciTech Connect

    Daley, T.M.; Majer, E.L.; Karageorgi, E.

    1994-08-01

    This report presents results from surface and borehole seismic profiling performed by the Lawrence Berkeley Laboratory (LBL) on Yucca Mountain. This work was performed as part of the site characterization effort for the potential high-level nuclear waste repository. Their objective was to provide seismic imaging from the near surface (200 to 300 ft. depth) to the repository horizon and below, if possible. Among the issues addressed by this seismic imaging work are location and depth of fracturing and faulting, geologic identification of reflecting horizons, and spatial continuity of reflecting horizons. The authors believe their results are generally positive, with tome specific successes. This was the first attempt at this scale using modem seismic imaging techniques to determine geologic features on Yucca Mountain. The principle purpose of this report is to present the interpretation of the seismic reflection section in a geologic context. Three surface reflection profiles were acquired and processed as part of this study. Because of environmental concerns, all three lines were on preexisting roads. Line 1 crossed the mapped surface trace of the Ghost Dance fault and it was intended to study the dip and depth extent of the fault system. Line 2 was acquired along Drill Hole wash and was intended to help the ESF north ramp design activities. Line 3 was acquired along Yucca Crest and was designed to image geologic horizons which were thought to be less faulted along the ridge. Unfortunately, line 3 proved to have poor data quality, in part because of winds, poor field conditions and limited time. Their processing and interpretation efforts were focused on lines 1 and 2 and their associated VSP studies.

  6. Modeling studies of gas movement and moisture migration at Yucca Mountain, Nevada

    SciTech Connect

    Tsang, Y.W.; Pruess, K.

    1991-06-01

    Modeling studies on moisture redistribution processes that are mediated by gas phase flow and diffusion have been carried out. The problem addressed is the effect of a lowered humidity of the soil gas at the land surface on moisture removal from Yucca Mountain, the potential site for a high-level nuclear waste repository. At the land surface, humid formation gas contacts much drier atmospheric air. Near this contact, the humidity of the soil gas may be considerably lower than at greater depth, where the authors expect equilibrium with the liquid phase and close to 100% humidity. The lower relative humidity of the soil gas may be modeled by imposing, at the land surface, an additional negative capillary suction corresponding to vapor pressure lowering according to Kelvin`s Equation, thus providing a driving force for the upward movement of moisture in both the vapor and liquid phases. Sensitivity studies show that moisture removal from Yucca Mountain arising from the lowered-relative-humidity boundary condition is controlled by vapor diffusion. There is much experimental evidence in the soil literature that diffusion of vapor is enhanced due to pore-level phase change effects by a few orders of magnitude. Modeling results presented here will account for this enhancement in vapor diffusion.

  7. Site characterization progress report: Yucca Mountain, Nevada. Number 15, April 1--September 30, 1996

    SciTech Connect

    1997-04-01

    During the second half of fiscal year 1996, activities at the Yucca Mountain Site Characterization Project (Project) supported the objectives of the revised Program Plan released this period by the Office of Civilian Radioactive Waste Management of the US Department of Energy (Department). Outlined in the revised plan is a focused, integrated program of site characterization, design, engineering, environmental, and performance assessment activities that will achieve key Program and statutory objectives. The plan will result in the development of a license application for repository construction at Yucca Mountain, if the site is found suitable. Activities this period focused on two of the three near-term objectives of the revised plan: updating in 1997 the regulatory framework for determining the suitability of the site for the proposed repository concept and providing information for a 1998 viability assessment of continuing toward the licensing of a repository. The Project has also developed a new design approach that uses the advanced conceptual design published during the last reporting period as a base for developing a design that will support the viability assessment. The initial construction phase of the Thermal Testing Facility was completed and the first phase of the in situ heater tests began on schedule. In addition, phase-one construction was completed for the first of two alcoves that will provide access to the Ghost Dance fault.

  8. Scenarios constructed for nominal flow in the presence of a repository at Yucca Mountain and vicinity

    SciTech Connect

    Barr, G.E.; Hunter, R.L.; Dunn, E.; Flint, A.

    1995-03-01

    Scenario development for the system performance assessment of the Yucca Mountain Site Characterization Project defines a scenario as a well-posed problem connecting an initiating event with radionuclide release to the accessible environment by a logical and physically possible combination or sequence of features, events, and processes. Drawing on the advice and assistance of the Project`s principal investigators (PIs), a collection of release scenarios initiated by the nominal ground-water flow occurring in the vicinity of the potential Yucca Mountain high-level-waste repository is developed and described in pictorial form. This collection of scenarios is intended to provide a framework to assist PIs in recognizing essential field and calculational analyses, to assist performance assessment in providing guidance to site characterization, and to continue the effort to exhaustively identify all features, events, and processes important to releases. It represents a step in the iterative process of identifying what details of the potential site are important for safe disposal. 67 refs.

  9. Total-system performance assessment for Yucca Mountain -- SNL second iteration (TSPA-1993); Executive summary

    SciTech Connect

    Wilson, M.L.; Barnard, R.W.; Gauthier, J.H. |

    1994-04-01

    Sandia National Laboratories has completed the second iteration of the periodic total-system performance assessments (TSPA-93) for the Yucca Mountain Site Characterization Project (YMP). Scenarios describing expected conditions (aqueous and gaseous transport of contaminants) and low-probability events (human-intrusion drilling and volcanic intrusion) are modeled. The hydrologic processes modeled include estimates of the perturbations to ambient conditions caused by heating of the repository resulting from radioactive decay of the waste. TSPA-93 incorporates significant new detailed process modeling, including two- and three-dimensional modeling of thermal effects, groundwater flow in the saturated-zone aquifers, and gas flow in the unsaturated zone. Probabilistic analyses are performed for aqueous and gaseous flow and transport, human intrusion, and basaltic magmatic activity. Results of the calculations lead to a number of recommendations concerning studies related to site characterization. Primary among these are the recommendations to obtain better information on percolation flux at Yucca Mountain, on the presence or absence of flowing fractures, and on physical and chemical processes influencing gaseous flow. Near-field thermal and chemical processes, and waste-container degradation are also areas where additional investigations may reduce important uncertainties. Recommendations for repository and waste-package design studies are: (1) to evaluate the performance implications of large-size containers, and (2) to investigate in more detail the implications of high repository thermal power output on the adjacent host rock and on the spent fuel.

  10. Simultaneous inversion of air-injection tests in fractured unsaturated tuff at Yucca Mountain

    NASA Astrophysics Data System (ADS)

    Huang, K.; Tsang, Y. W.; Bodvarsson, G. S.

    1999-08-01

    Air-injection tests are being used to characterize the flow characteristics of the fractured volcanic tuffs at Yucca Mountain, Nevada, the proposed site for a high-level nuclear waste repository. As the air component flows mainly in the heterogeneous fracture system, air-injection tests can be used to determine the hydrological properties and parameters of the fracture networks. In situ air-injection tests have been carried out in 30 boreholes drilled in a fractured rock block of 13 × 21.5 × 18 m3 in the underground facility at Yucca Mountain. These in situ field tests consist of a constant rate flow injection in one of the boreholes, while the pressure response is monitored in all 30 boreholes of the rock block. This paper presents a simultaneous inversion for 21 air-injection tests in 21 separate boreholes using TOUGH2, a three-dimensional numerical code for multiphase, multicomponent transport [Pruess, 1991; Pruess et al., 1996]. Spatially variable fracture permeability is used as an adjustable parameter to fit the measured pressure responses. For most of the pneumatic experiments the calculated pressure changes match the measured data well. Estimated permeabilities range over 5 orders of magnitude, from 10-15 to 8 × 10-11 m2, indicating large spatial variability in permeability of the heterogeneous fracture system.

  11. Physical and chemical characteristics of topographically affected airflow in an open borehole at Yucca Mountain, Nevada

    SciTech Connect

    Thorstenson, D.C.; Woodward, J.C.; Weeks, E.P.; Haas, H.

    1989-12-31

    Borehole UZ6S, on the crest of Yucca Mountain, Nevada Test Site, has exhaled approximately 10{sup 6} m{sup 3} of gas annually during winter months for three successive years. The flow arises from thermal-topographic effects. The average composition of the exhausted gas is: N{sub 2} = 78%, O{sub 2} = 21%, Ar = 0.94%, CO{sub 2} = 0.125%, and CH{sub 4} = 0.2 ppMv. The CO{sub 2} has the following isotopic signature: {sup 14}C = 108.5 percent modern carbon (pmc), and {delta}{sup 13}C = 17.1 per mil. In the thirty-month observation period, there has been a net flux to the atmosphere of approximately 40 m{sup 3} of liquid water and 1150 kg of carbon. The gas flowing from UZ6S appears to originate in the soil and/or shallow unsaturated zone at Yucca Mountain crest. 25 refs., 6 figs., 4 tabs.

  12. Site characterization plan overview: Yucca Mountain site, Nevada Research and Development Area, Nevada

    SciTech Connect

    1988-12-01

    To help the public better understand both the SCP and the site characterization program, the DOE has prepared this overview and the SCP Public Handbook. The overview presents summaries of selected topics covered in the SCP; it is not a substitute for the SCP. The organization of the overview is similar to that of the SCP itself, with brief descriptions of the Yucca Mountain site, the repository, and the containers in which the waste would be packaged, followed by a discussion of the characterization program to be carried out at the Yucca Mountain site. This overview is intended primarily for those persons who want to understand the general scope and basis of the site-characterization program, the activities to be conducted, and the facilities to be constructed without spending the time necessary to become familiar with all of the technical details presented in the SCP. For the readers of the SCP, the overview will be useful as a general guide to the plan. The SCP Public Handbook is a short document that contains brief descriptions of the SCP process and the contents of the SCP. It also explains how the public can submit comments on the SCP and lists the libraries and reading rooms at which the SCP is available. 9 refs., 18 tabs.

  13. Implementation of Localized Corrosion in the Performance Assessment Model for Yucca Mountain

    SciTech Connect

    Vivek Jain, S. David Sevougian, Patrick D. Mattie, Kevin G. Mon, and Robert J. Mackinnon

    2006-04-30

    A total system performance assessment (TSPA) model has been developed to analyze the ability of the natural and engineered barriers of the Yucca Mountain repository to isolate nuclear waste over the 10,000-year period following repository closure. The principal features of the engineered barrier system (EBS) are emplacement tunnels (or ''drifts'') containing a two-layer waste package (WP) for waste containment and a titanium drip shield to protect the waste package from seeping water and falling rock, The 20-mm-thick outer shell of the WP is composed of Alloy 22, a highly corrosion-resistant nickel-based alloy. The barrier function of the EBS is to isolate the waste from migrating water. The water and its associated chemical conditions eventually lead to degradation of the waste packages and mobilization of the radionuclides within the packages. There are five possible waste package degradation modes of the Alloy 22: general corrosion, microbially influenced corrosion, stress corrosion cracking, early failure due to manufacturing defects, and localized corrosion. This paper specifically examines the incorporation of the Alloy-22 localized corrosion model into the Yucca Mountain TSPA model, particularly the abstraction and modeling methodology, as well as issues dealing with scaling, spatial variability, uncertainty, and coupling to other sub-models that are part of the total system model.

  14. Performance assessment model development and analysis of radionuclide transport in the unsaturated zone, Yucca Mountain, Nevada.

    PubMed

    Robinson, Bruce A; Li, Chunhong; Ho, Clifford K

    2003-01-01

    This paper describes the development and use of a particle-tracking model to perform radionuclide-transport simulations in the unsaturated zone at Yucca Mountain, Nevada. The goal of the effort was to produce a computational model that can be coupled to the project's calibrated 3D site-scale flow model so that the results of that effort could be incorporated directly into the Total System Performance Assessment (TSPA) analyses. The transport model simulates multiple species (typically 20 or more) with complex time-varying and spatially varying releases from the potential repository. Water-table rise, climate-change scenarios, and decay chains are additional features of the model. A cell-based particle-tracking method was employed that includes a dual-permeability formulation, advection, longitudinal dispersion, matrix diffusion, and colloid-facilitated transport. This paper examines the transport behavior of several key radionuclides through the unsaturated zone using the calibrated 3D unsaturated flow fields. Computational results illustrate the relative importance of fracture flow, matrix diffusion, and lateral diversion on the distribution of travel times from the simulated repository to the water table for various climatic conditions. Results also indicate rapid transport through fractures for a portion of the released mass. Further refinement of the model will address several issues, including conservatism in the transport model, the assignment of parameters in the flow and transport models, and the underlying assumptions used to support the conceptual models of flow and transport in the unsaturated zone at Yucca Mountain. PMID:12714294

  15. Effect of heterogeneity on radionuclide retardation in the alluvial aquifer near Yucca Mountain, Nevada.

    PubMed

    Painter, S; Cvetkovic, V; Turner, D R

    2001-01-01

    The U.S. Department of Energy is currently studying Yucca Mountain, Nevada, as a potential site for a geological high-level waste repository. In the current conceptual models of radionuclide transport at Yucca Mountain, part of the transport path to pumping locations would be through an alluvial aquifer. Interactions with minerals in the alluvium are expected to retard the downstream migration of radionuclides, thereby delaying arrival times and reducing ground water concentrations. We evaluate the effectiveness of the alluvial aquifer as a transport barrier using the stochastic Lagrangian framework. A transport model is developed to account for physical and chemical heterogeneities and rate-limited mass transfer between mobile and immobile zones. The latter process is caused by small-scale heterogeneity and is thought to control the macroscopic-scale retardation in some field experiments. A geostatistical model for the spatially varying sorption parameters is developed from a site-specific database created from hydrochemical measurements and a calibrated modeling approach (Turner and Pabalan 1999). Transport of neptunium is considered as an example. The results are sensitive to the rate of transfer between mobile and immobile zones, and to spatial variability in the hydraulic conductivity. Chemical heterogeneity has only a small effect, as does correlation between hydraulic conductivity and the neptunium distribution coefficient. These results illustrate how general sensitivities can be explored with modest effort within the Lagrangian framework. Such studies complement and guide the application of more detailed numerical simulations. PMID:11340997

  16. Atmospheric Dispersal and Dispostion of Tephra From a Potential Volcanic Eruption at Yucca Mountain, Nevada

    SciTech Connect

    G. Keating; W.Statham

    2004-02-12

    The purpose of this model report is to provide documentation of the conceptual and mathematical model (ASHPLUME) for atmospheric dispersal and subsequent deposition of ash on the land surface from a potential volcanic eruption at Yucca Mountain, Nevada. This report also documents the ash (tephra) redistribution conceptual model. The ASHPLUME conceptual model accounts for incorporation and entrainment of waste fuel particles associated with a hypothetical volcanic eruption through the Yucca Mountain repository and downwind transport of contaminated tephra. The ASHPLUME mathematical model describes the conceptual model in mathematical terms to allow for prediction of radioactive waste/ash deposition on the ground surface given that the hypothetical eruptive event occurs. This model report also describes the conceptual model for tephra redistribution from a basaltic cinder cone. Sensitivity analyses and model validation activities for the ash dispersal and redistribution models are also presented. Analyses documented in this model report will improve and clarify the previous documentation of the ASHPLUME mathematical model and its application to the Total System Performance Assessment (TSPA) for the License Application (TSPA-LA) igneous scenarios. This model report also documents the redistribution model product outputs based on analyses to support the conceptual model.

  17. Modeling Unsaturated Flow and Transport Processes in Fractured Tuffs of Yucca Mountain

    SciTech Connect

    Wu, Yu-Shu; Lu, Guoping; Zhang, Keni; Bodvarsson, G.S.

    2003-07-15

    This paper presents a field modeling study characterizing fluid flow and tracer transport in the unsaturated zone of Yucca Mountain, Nevada, a proposed underground repository for storing high-level radioactive waste. The 500 to 700 meter thick unsaturated zone of Yucca Mountain consists of highly heterogeneous layers of anisotropic, fractured ash flow and air fall tuffs. Characterization of fluid flow and heat transfer through such a system has been a challenge due to the heterogeneities prevalent on various scales. Quantitative evaluation of water, gas, and heat flow by means of numerical simulation is essential for design and performance assessment of the repository. A three-dimensional numerical flow and transport model will be discussed. The model has been calibrated against field-measured data and takes into account the coupled processes of unsaturated flow and tracer transport in the highly heterogeneous, unsaturated fractured porous rock. The modeling approach of the model is based on a dual-continuum formulation of coupled multiphase fluid and tracer transport through fractured porous rock. As application examples, effects of current and future climates on the unsaturated zone processes are evaluated to aid in the assessment of the proposed repository's system performance.

  18. Chemical analyses of rocks, minerals, and detritus, Yucca Mountain--Preliminary report, special report No. 11

    SciTech Connect

    Hill, C.A.; Livingston, D.E.

    1993-09-01

    This chemical analysis study is part of the research program of the Yucca Mountain Project intended to provide the State of Nevada with a detailed assessment of the geology and geochemistry of Yucca Mountain and adjacent regions. This report is preliminary in the sense that more chemical analyses may be needed in the future and also in the sense that these chemical analyses should be considered as a small part of a much larger geological data base. The interpretations discussed herein may be modified as that larger data base is examined and established. All of the chemical analyses performed to date are shown in Table 1. There are three parts to this table: (1) trace element analyses on rocks (limestone and tuff) and minerals (calcite/opal), (2) rare earth analyses on rocks (tuff) and minerals (calcite/opal), and (3) major element analyses + CO{sub 2} on rocks (tuff) and detritus sand. In this report, for each of the three parts of the table, the data and its possible significance will be discussed first, then some overall conclusions will be made, and finally some recommendations for future work will be offered.

  19. Evaluation of the US DOE's conceptual model of hydrothermal activity at Yucca Mountain, Nevada

    NASA Astrophysics Data System (ADS)

    Dublyansky, Y. V.

    2014-08-01

    A unique conceptual model describing the conductive heating of rocks in the thick unsaturated zone of Yucca Mountain, Nevada by a silicic pluton emplaced several kilometers away is accepted by the US Department of Energy (DOE) as an explanation of the elevated depositional temperatures measured in fluid inclusions in secondary fluorite and calcite. Acceptance of this model allowed the DOE to keep from considering hydrothermal activity in the performance assessment of the proposed high-level nuclear waste disposal facility. The evaluation presented in this paper shows that no computational modeling results have yet produced a satisfactory match with the empirical benchmark data, specifically with age and fluid inclusion data that indicate high temperatures (up to ca. 80 °C) in the unsaturated zone of Yucca Mountain. Auxiliary sub-models complementing the DOE model, as well as observations at a natural analog site, have also been evaluated. Summarily, the model cannot be considered as validated. Due to the lack of validation, the reliance on this model must be discontinued and the appropriateness of decisions which rely on this model must be re-evaluated.

  20. Chemical composition of ground water in the Yucca Mountain area, Nevada, 1971-84

    USGS Publications Warehouse

    Benson, L.V.; McKinley, P.W.

    1985-01-01

    Fifteen wells in the Yucca Mountain area of southern Nevada have been sampled for chemical analysis. Samples were obtained by pumping water from the entire well bore (composite sample), and, in three instances, by pumping from one or more isolated intervals within a well bore. Sodium is the most abundant cation , and biocarbonate is the most abundant anion in all water samples. Samples from the Paleozoic carbonate aquifer penetrated by well UE-25p 1 contain higher relative concentrations of calcium and magnesium than samples from overlying volcanic tuffs. Values of the stable isotope concentrations of oxygen and hydrogen are relatively negative (light) and have deuterium excess values ranging from +5 to +10. The distribution of uncorrected radiocarbon ages of tuffaceous groundwater from samples within one kilometer of the exploratory block ranges from 12,000 to 18,500 years before present. Variation in the inorganic, stable, and radioactive isotope composition of samples indicates a significant degree of lateral and vertical chemical inhomogeneity in groundwater of the Yucca Mountain area. (USGS)

  1. Verification of a 1-dimensional model for predicting shallow infiltration at Yucca Mountain

    SciTech Connect

    Hevesi, J.A.; Flint, A.L.; Flint, L.E.

    1994-12-31

    A characterization of net infiltration rates is needed for site-scale evaluation of groundwater flow at Yucca Mountain, Nevada. Shallow infiltration caused by precipitation may be a potential source of net infiltration. A 1-dimensional finite difference model of shallow infiltration with a moisture-dependant evapotranspiration function and a hypothetical root-zone was calibrated and verified using measured water content profiles, measured precipitation, and estimated potential evapotranspiration. Monthly water content profiles obtained from January 1990 through October 1993 were measured by geophysical logging of 3 boreholes located in the alluvium channel of Pagany Wash on Yucca Mountain. The profiles indicated seasonal wetting and drying of the alluvium in response to winter season precipitation and summer season evapotranspiration above a depth of 2.5 meters. A gradual drying trend below a depth of 2.5 meters was interpreted as long-term redistribution and/or evapotranspiration following a deep infiltration event caused by runoff in Pagany Wash during 1984. An initial model, calibrated using the 1990 to 1 992 record, did not provide a satisfactory prediction of water content profiles measured in 1993 following a relatively wet winter season. A re-calibrated model using a modified, seasonally-dependent evapotranspiration function provided an improved fit to the total record. The new model provided a satisfactory verification using water content changes measured at a distance of 6 meters from the calibration site, but was less satisfactory in predicting changes at a distance of 18 meters.

  2. Yellowstone as an Analog for Thermal-Hydrological-Chemical Processes at Yucca Mountain

    SciTech Connect

    P. F. Dobson; T. J. Kneafsey; A. Simmons; J. Hulen

    2001-05-29

    Enhanced water-rock interaction resulting from the emplacement of heat-generating nuclear waste in the potential geologic repository at Yucca Mountain, Nevada, may result in changes to fluid flow (resulting from mineral dissolution and precipitation in condensation and boiling zones, respectively). Studies of water-rock interaction in active and fossil geothermal systems (natural analogs) provide evidence for changes in permeability and porosity resulting from thermal-hydrological-chemical (THC) processes. The objective of this research is to document the effects of coupled THC processes at Yellowstone and then examine how differences in scale could influence the impact that these processes may have on the Yucca Mountain system. Subsurface samples from Yellowstone National Park, one of the largest active geothermal systems in the world, contain some the best examples of hydrothermal self-sealing found in geothermal systems. We selected core samples from two USGS research drill holes from the transition zone between conductive and convective portions of the geothermal system (where sealing was reported to occur). We analyzed the core, measuring the permeability, porosity, and grain density of selected samples to evaluate how lithology, texture, and degree of hydrothermal alteration influence matrix and fracture permeability.

  3. Exploratory Shaft Seismic Design Basis Working Group report; Yucca Mountain Project

    SciTech Connect

    Subramanian, C.V.; King, J.L.; Perkins, D.M.; Mudd, R.W.; Richardson, A.M.; Calovini, J.C.; Van Eeckhout, E.; Emerson, D.O.

    1990-08-01

    This report was prepared for the Yucca Mountain Project (YMP), which is managed by the US Department of Energy. The participants in the YMP are investigating the suitability of a site at Yucca Mountain, Nevada, for construction of a repository for high-level radioactive waste. An exploratory shaft facility (ESF) will be constructed to permit site characterization. The major components of the ESF are two shafts that will be used to provide access to the underground test areas for men, utilities, and ventilation. If a repository is constructed at the site, the exploratory shafts will be converted for use as intake ventilation shafts. In the context of both underground nuclear explosions (conducted at the nearby Nevada Test Site) and earthquakes, the report contains discussions of faulting potential at the site, control motions at depth, material properties of the different rock layers relevant to seismic design, the strain tensor for each of the waveforms along the shaft liners, and the method for combining the different strain components along the shaft liners. The report also describes analytic methods, assumptions used to ensure conservatism, and uncertainties in the data. The analyses show that none of the shafts` structures, systems, or components are important to public radiological safety; therefore, the shafts need only be designed to ensure worker safety, and the report recommends seismic design parameters appropriate for this purpose. 31 refs., 5 figs., 6 tabs.

  4. Application of quality assurance controls to TBM tunneling on the Yucca Mountain Project

    SciTech Connect

    Christensen, J.D.

    1996-06-01

    As part of the Yucca Mountain Project (YMP), a 7.62-meter diameter tunnel is being constructed using a Tunnel Boring Machine (TBM). This tunnel, which may form a portion of a permanent high-level nuclear waste repository, is being constructed under the auspices of a nuclear quality assurance (QA) program. The YMP nuclear QA program applies to items and activities determined to be important to radiological safety, waste isolation, and potential interactions with the environment. The items and activities determined to be important have been assigned a quality assurance classification. This paper focuses on the items (rockbolts, steel sets, and shotcrete) and quality affecting activities involved in providing ground support and excavating the tunnel. Typical activities that have been assigned QA classifications include TBM maintenance, control of water used in the tunnel during construction, and control of diesel emissions in the tunnel. The paper concludes that the key to the successful implementation of nuclear QA requirements for tunneling at Yucca Mountain was the assignment of personnel with the appropriate mix of tunneling and nuclear experience.

  5. Numerical simulation of gas flow through unsaturated fractured rock at Yucca Mountain, Nevada

    SciTech Connect

    Cooper, C.A.

    1990-01-01

    Numerical analysis is used to identify the physical phenomena associated with barometrically driven gas (air and water vapor) flow through unsaturated fractured rock at Yucca Mountain, Nevada. Results from simple finite difference simulations indicate that for a fractured rock scenario, the maximum velocity of air out of an uncased 10 cm borehole is 0.002 m s{sub {minus}1}. An equivalent porous medium (EPM) model was incorporated into a multiphase, multicomponent simulator to test more complex conceptual models. Results indicate that for a typical June day, a diurnal pressure wave propagates about 160 m into the surrounding Tiva Canyon hydrogeologic unit. Dry air that enters the formation evaporates water around the borehole which reduces capillary pressure. Multiphase countercurrent flow develops in the vicinity of the hole; the gas phase flows into the formation while the liquid phase flows toward the borehole. The effect occurs within 0.5 m of the borehole. The amount of water vapor leaving the formation during 1 day is 900 cm{sup 3}. This is less than 0.1% of the total recharge into the formation, suggesting that the barometric effect may be insignificant in drying the unsaturated zone. However, gas phase velocities out of the borehole (3 m s{sup {minus}1}), indicating that observed flow rates from wells along the east flank of Yucca Mountain were able to be simulated with a barometric model.

  6. Characterization of arid land water-balance processes at Yucca Mountain, Nevada

    NASA Astrophysics Data System (ADS)

    Flint, Alan L.; Flint, Lorraine E.; Hevesi, Joseph A.; Hudson, David B.

    Water-balance processes were characterized to estimate net infiltration at Yucca Mountain, Nevada, to help determine the suitability of this site as a potential high-level radioactive waste repository. Detailed water-content data were collected from 98 boreholes located in four topographic positions (ridgetops, sideslopes, albvial terraces, and active channels) representing four infiltration zones. These data include monthly volumetric water-content readings with depth for 1984 through 1995 and water potential measurements made at a soil-bedrock contact in 1995. These data, combined with measured evapotranspiration and precipitation data, piovide the seasonal and areal distribution of changes in volumetric water content needed to assess hydrologic processes contributing to net infiltration. The conceptual model of infiltration at Yucca Mountain describes the processes of precipitation, runoff, evapotranspiration, and vertical redistribution of water in the shallow unsaturated zone. Field observations and measurements and data analysis indicate that, in order for net infiltration to occur, water must reach and nearly saturate the soil-bedrock contact to initiate flow in the underlying fractured bedrock, and water must penetrate deep enough to escape the influences of evapotranspiration. The amount of net infiltration is a function of how long or how frequently the contact is saturated. Water must penetrate deep enough to escape the influences of evapotranspiration. The penetration of water through the soil is influenced primarily by the seasonal timing and areal distribution of precipitation, the storage capacity of soil, and the properties of the underlying bedrock.

  7. The use of chlorine isotope measurements to trace water movements at Yucca Mountain

    SciTech Connect

    Norris, A.E.

    1989-08-01

    The rates of water movements in the tuffs at Yucca Mountain are important for assessing the performance of a potential high-level nuclear waste repository. Measurements of cosmogenic 3.0 {times} 10{sup 5} yr {sup 36}Cl in tuff from the unsaturated zone and in water from the saturated zone can provide information about water movements over times of 10{sup 15} to 10{sup 6} years. The data derived from the analysis of cuttings from a dry-drilled hole at Yucca Mountain indicate the presence of a {sup 36}Cl background that must be taken into account for proper interpretation of the {sup 36}Cl interpretation of the {sup 36}Cl results. Similarly, the {sup 36}Cl measured in water from the saturated zone requires additional work for correct interpretation. Fallout of {sup 36}Cl from nuclear weapons tests between 1952 and 1962 provided a tracer for an infiltration study. Measurements of the {sup 36}Cl bomb pulse in tuffs from the unsaturated zone show potential for tracing recent water flow in faults and fractures. 5 refs.

  8. Quaternary allostratigraphy of surficial deposit map units at Yucca Mountain, Nevada: A progress report

    SciTech Connect

    Lundstrom, S.C. ); Wesling, J.R.; Swan, F.H. ); Taylor, E.M.; Whitney, J.W. )

    1993-04-01

    Surficial geologic mapping at Yucca Mountain, Nevada, is relevant to site characterization studies of paleoclimate, tectonics, erosion, flood hazards, and water infiltration. Alluvial, colluvial, and eolian allostratigraphic map units are defined on the basis of age-related surface characteristics and soil development, as well as lithology and sedimentology indicative of provenance and depositional mode. In gravelly alluvial units, which include interbedded debris flows, the authors observe a useful qualitative correlation between surface and soil properties. Map units of estimated middle Pleistocene age typically have a well-developed, varnished desert pavement, and minimal erosional and preserved depositional microrelief, associated with a soil with a reddened Bt horizon and stage 3 carbonate and silica morphology. Older units have greater erosional relief, an eroded argillic horizon and stage 4 carbonate morphology, whereas younger units have greater preservation of depositional morphology, but lack well-developed pavements, rock varnish, and Bt and Kqm soil horizons. Trench and gully-wall exposures show that alluvial, colluvial and eolian dominated surface units are underlain by multiple buried soils separating sedimentologically similar deposits; this stratigraphy increases the potential for understanding the long-term Quaternary paleoenvironmental history of Yucca Mountain. Age estimates for allostratigraphic units, presently based on uranium-trend dating and regional correlation using soil development, will be further constrained by ongoing dating studies that include tephra identification, uranium-series disequilibrium, and thermoluminescence methods.

  9. A Fruit of Yucca Mountain: The Remote Waste Package Closure System

    SciTech Connect

    Kevin Skinner; Greg Housley; Colleen Shelton-Davis

    2011-11-01

    Was the death of the Yucca Mountain repository the fate of a technical lemon or a political lemon? Without caution, this debate could lure us away from capitalizing on the fruits of the project. In March 2009, Idaho National Laboratory (INL) successfully demonstrated the Waste Package Closure System, a full-scale prototype system for closing waste packages that were to be entombed in the now abandoned Yucca Mountain repository. This article describes the system, which INL designed and built, to weld the closure lids on the waste packages, nondestructively examine the welds using four different techniques, repair the welds if necessary, mitigate crack initiating stresses in the surfaces of the welds, evacuate and backfill the packages with an inert gas, and perform all of these tasks remotely. As a nation, we now have a proven method for securely sealing nuclear waste packages for long term storage—regardless of whether or not the future destination for these packages will be an underground repository. Additionally, many of the system’s features and concepts may benefit other remote nuclear applications.

  10. Mechanical defradation of Emplacement Drifts at Yucca Mountain- A Modeling Case Study. Part I: Nonlithophysal Rock

    SciTech Connect

    M. Lin; D. Kicker; B. Damjanac; M. Board; M. Karakouzian

    2006-07-05

    This paper outlines rock mechanics investigations associated with mechanical degradation of planned emplacement drifts at Yucca Mountain, which is the designated site for the proposed U.S. high-level nuclear waste repository. The factors leading to drift degradation include stresses from the overburden, stresses induced by the heat released from the emplaced waste, stresses due to seismically related ground motions, and time-dependent strength degradation. The welded tuff emplacement horizon consists of two groups of rock with distinct engineering properties: nonlithophysal units and lithophysal units, based on the relative proportion of lithophysal cavities. The term 'lithophysal' refers to hollow, bubble like cavities in volcanic rock that are surrounded by a porous rim formed by fine-grained alkali feldspar, quartz, and other minerals. Lithophysae are typically a few centimeters to a few decimeters in diameter. Part I of the paper concentrates on the generally hard, strong, and fractured nonlithophysal rock. The degradation behavior of the tunnels in the nonlithophysal rock is controlled by the occurrence of keyblocks. A statistically equivalent fracture model was generated based on extensive underground fracture mapping data from the Exploratory Studies Facility at Yucca Mountain. Three-dimensional distinct block analyses, generated with the fracture patterns randomly selected from the fracture model, were developed with the consideration of in situ, thermal, and seismic loads. In this study, field data, laboratory data, and numerical analyses are well integrated to provide a solution for the unique problem of modeling drift degradation.

  11. Hydrologic inferences from strontium isotopes in pore water from the unsaturated zone at Yucca Mountain, Nevada

    SciTech Connect

    Marshall, B.D.; Futa, K.; Peterman, Z.E.

    1997-12-31

    Calcite is ubiquitous at Yucca Mountain, occurring in the soils and as fracture and cavity coatings within the volcanic tuff section. Strontium is a trace element in calcite, generally at the tens to hundreds of ppm level. Because calcite contains very little rubidium and the half-life of the {sup 87}Rb parent is billions of years, the {sup 87}Sr/{sup 86}Sr ratios of the calcite record the ratio in the water from which the calcite precipitated. Dissolution and reprecipitation does not alter these compositions so that, in the absence of other sources of strontium, one would expect the strontium ratios along a flow path to preserve variations inherited from strontium in the soil zone. Strontium isotope compositions of calcites from various settings in the Yucca Mountain region have contributed to the understanding of the unsaturated zone (UZ), especially in distinguishing unsaturated zone calcite from saturated zone calcite. Different populations of calcite have been compared, either to group them together or distinguish them from each other in terms of their strontium isotope compositions. Ground water and perched water have also been analyzed; this paper presents strontium isotope data obtained on pore water.

  12. Estimation of hydraulic conductivities of Yucca Mountain tuffs from sorptivity and water retention measurements

    SciTech Connect

    Zimmerman, R.W.; Bodvarsson, G.S.

    1995-06-01

    The hydraulic conductivity functions of the matrix rocks at Yucca Mountain, Nevada, are among the most important data needed as input for the site-scale hydrological model of the unsaturated zone. The difficult and time-consuming nature of hydraulic conductivity measurements renders it infeasible to directly measure this property on large numbers of cores. Water retention and sorptivity measurements, however, can be made relatively rapidly. The sorptivity is, in principle, a unique functional of the conductivity and water retention functions. It therefore should be possible to invert sorptivity and water retention measurements in order to estimate the conductivity; the porosity is the only other parameter that is required for this inversion. In this report two methods of carrying out this inversion are presented, and are tested against a limited data set that has been collected by Flint et al. at the USGS on a set of Yucca Mountain tuffs. The absolute permeability is usually predicted by both methods to within an average error of about 0.5 - 1.0 orders of magnitude. The discrepancy appears to be due to the fact that the water retention curves have only been measured during drainage, whereas the imbibition water retention curve is the one that is relevant to sorptivity measurements. Although the inversion methods also yield predictions of the relative permeability function, there are yet no unsaturated hydraulic conductivity data against which to test these predictions.

  13. Influence of transitional volcanic strata on lateral diversion at Yucca Mountain, Nevada

    USGS Publications Warehouse

    Flint, L.E.; Flint, A.L.; Selker, J.S.

    2003-01-01

    Natural hydraulic barriers exist at Yucca Mountain, Nevada, a potential high-level nuclear waste repository, that have been identified as possible lateral diversions for reducing deep percolation through the waste storage area. Historical development of the conceptual model of lateral diversion has been limited by available field data, but numerical investigations presented the possibility of significant lateral diversion due to the presence of a thin, porous rock layer, the Paintbrush nonwelded tuffs. Analytical analyses of the influence of transitional changes in properties suggest that minimal lateral diversion is likely at Yucca Mountain. Numerical models, to this point, have not accounted for the gradual transition of properties or the existence of multiple layers that could inadvertently influence the simulation of lateral diversion as an artifact of numerical model discretization. Analyses were made of subsurface matric potential measurements, and comparisons were made of surface infiltration estimates with deeper percolation flux calculations using chloride-mass-balance calculations and simulations of measured temperature profiles. These analyses suggest that insignificant lateral diversion has occurred above the repository horizon and that water generally moves vertically through the Paintbrush nonwelded tuffs.

  14. Verification of a 1-dimensional model for predicting shallow infiltration at Yucca Mountain

    SciTech Connect

    Hevesi, J.; Flint, A.L.; Flint, L.E.

    1994-12-31

    A characterization of net infiltration rates is needed for site-scale evaluation of groundwater flow at Yucca Mountain, Nevada. Shallow infiltration caused by precipitation may be a potential source of net infiltration. A 1-dimensional finite difference model of shallow infiltration with a moisture-dependent evapotranspiration function and a hypothetical root-zone was calibrated and verified using measured water content profiles, measured precipitation, and estimated potential evapotranspiration. Monthly water content profiles obtained from January 1990 through October 1993 were measured by geophysical logging of 3 boreholes located in the alluvium channel of Pagany Wash on Yucca Mountain. The profiles indicated seasonal wetting and drying of the alluvium in response to winter season precipitation and summer season evapotranspiration above a depth of 2.5 meters. A gradual drying trend below a depth of 2.5 meters was interpreted as long-term redistribution and/or evapotranspiration following a deep infiltration event caused by runoff in Pagany Wash during 1984. An initial model, calibrated using the 1990 to 1992 record, did not provide a satisfactory prediction of water content profiles measured in 1993 following a relatively wet winter season. A re-calibrated model using a modified, seasonally-dependent evapotranspiration function provided an improved fit to the total record. The new model provided a satisfactory verification using water content changes measured at a distance of 6 meters from the calibration site, but was less satisfactory in predicting changes at a distance of 18 meters.

  15. Hydrogeology of the unsaturated zone, North Ramp area of the Exploratory Studies Facility, Yucca Mountain, Nevada

    SciTech Connect

    Rousseau, J.P.; Kwicklis, E.M.; Gillies, D.C.

    1999-03-01

    Yucca Mountain, in southern Nevada, is being investigated by the US Department of Energy as a potential site for a repository for high-level radioactive waste. This report documents the results of surface-based geologic, pneumatic, hydrologic, and geochemical studies conducted during 1992 to 1996 by the US Geological Survey in the vicinity of the North Ramp of the Exploratory Studies Facility (ESF) that are pertinent to understanding multiphase fluid flow within the deep unsaturated zone. Detailed stratigraphic and structural characteristics of the study area provided the hydrogeologic framework for these investigations. Shallow infiltration is not discussed in detail in this report because the focus in on three major aspects of the deep unsaturated-zone system: geologic framework, the gaseous-phase system, and the aqueous-phase system. However, because the relation between shallow infiltration and deep percolation is important to an overall understanding of the unsaturated-zone flow system, a summary of infiltration studies conducted to date at Yucca Mountain is provided in the section titled Shallow Infiltration. This report describes results of several Site Characterization Plan studies that were ongoing at the time excavation of the ESF North Ramp began and that continued as excavation proceeded.

  16. Yucca Mountain program summary of research and technical review activities, July 1988--June 1989

    SciTech Connect

    1989-11-01

    The Desert Research Institute (DRI), through its Water Resources Center (WRC), since 1984 has supported the State of Nevada Nuclear Waste Project Office`s activities related to the proposed high-level radioactive waste repository at Yucca Mountain on the Nevada Test Site (NTS). This effort is directed at providing the State Office with an unbiased evaluation of the Yucca Mountain Project (YMP) investigations performed by the US Department of Energy (DOE) and the Nuclear Regulatory Commission (NRC). The overall objective is to determine independently whether or not the site meets the performance criteria defined by the Nuclear Waste Policy Act of 1982 and amendments for isolating and containing the wastes during emplacement and the proposed life of the repository. A particularly important area of concern with the proposed repository is the site`s hydrology. The faculty of the DRI have long been involved with research throughout the State and have particular expertise in groundwater studies related to radionuclide migration and hydrologic safety of underground nuclear testing by DOE and predecessor agencies. In addition, we utilize laboratory personnel for chemical and isotopic analyses in both of the DRI-WMC water chemistry laboratories.

  17. Diet of desert tortoises at Yucca Mountain, Nevada, and implications for habitat reclamation

    SciTech Connect

    Rakestraw, D.L.; Holt, E.A.; Rautenstrauch, K.R.

    1995-12-01

    The diet of desert tortoises at Yucca Mountain was assessed during 1992 to 1995 using a combination of feeding observations and scat analysis. Feeding observation data (1993 through 1995) showed that tortoises fed on a wide variety of items. The most frequently eaten items were forbs and annual grasses. These two forage groups comprised more than 90% of all bites taken. Analysis of scat (1992 and 1993) also showed that grasses and forbs were the most common groups, making up more than 80% of the composition of scat. Yearly differences between proportions of species in the diet were observed and were most likely attributable to differences in plant productivity, which is linked to rainfall patterns. Non-native species were an important component of the diet in all years, accounting for 13 to 50% of all bites observed and 6 to 24% of scat contents. A list of all items encountered in the diet is provided. To facilitate reclamation of desert tortoise habitat disturbed by the Yucca Mountain Site Characterization Project, native forage species that should be included in reclamation seed mixes, when feasible, were identified. Although shrubs make up only a small proportion of the diet, they should also be included in reclamation efforts because they provide habitat structure. Tortoise cover sites, and microhabitats amenable to seed germination and seedling establishment. In addition, non-native species should not be planted on reclaimed sites and, if necessary, sites should be recontoured and soil compaction reduced prior to planting.

  18. Effects of magmatic processes on the potential Yucca Mountain repository: Field and computational studies

    SciTech Connect

    Valentine, G.A.; Groves, K.R.; Gable, C.W.; Perry, F.V.; Crowe, B.M.

    1993-10-01

    Assessing the risk of future magmatic activity at a potential Yucca Mountain radioactive waste repository requires, in addition to event probabilities, some knowledge of the consequences of such activity. Magmatic consequences are divided into an eruptive component, which pertains to the possibility of radioactive waste being erupted onto the surface of Yucca Mountain, and a subsurface component, which occurs whether there is an accompanying eruption or not. The subsurface component pertains to a suite of processes such as hydrothermal activity, changes in country rock properties, and long term alteration of the hydrologic flow field which change the waste isolation system. This paper is the second in a series describing progress on studies of the effects of magmatic activity. We describe initial results of field analog studies at small volume basaltic centers where detailed measurements are being conducted of the amount of wall rock debris that can be erupted as a function of depth in the volcanic plumbing system. Constraints from field evidence of wall rock entrainment mechanisms are also discussed. Evidence is described for a mechanism of producing subhorizontal sills versus subvertical dikes, an issue that is important for assessing subsurface effects. Finally, new modeling techniques, which are being developed in order to capture the three dimensional complexities of real geologic situations in subsurface effects, are described.

  19. Distribution of fast hydrologic paths in the unsaturated zone at Yucca Mountain

    SciTech Connect

    Fabryka-Martin, J.T.; Wolfsberg, A.V.; Levy, S.S.; Roach, J.L.; Winters, S.T.; Wolfsberg, L.E.; Elmore, D.; Sharma, P.

    1998-12-31

    Development and testing of conceptual flow and transport models for hydrologic systems are strengthened when natural environmental tracers are incorporated into the process. One such tracer is chlorine-36 ({sup 36}Cl, half-life, 301,000 years), a radioactive isotope produced in the atmosphere and carried underground with percolating groundwater. High concentrations of this isotope were also added to meteoric water during a period of global fallout from atmospheric testing of nuclear devices, primarily in the 1950s. This bomb-pulse signal has been used to test for the presence of fast transport paths in the unsaturated zone at Yucca Mountain and to provide the basis for a conceptual model for their distribution. Yucca Mountain is under investigation by the US Department of Energy as a potential site at which to host an underground high-level radioactive waste repository. Under wetter climatic conditions, fast-flow pathways will respond quickly to increases in infiltration and have the potential to become seeps in the tunnel drifts. The {sup 36}Cl data are also being used in numerical flow and transport models to establish lower bounds on infiltration rates, estimate ground water ages, and establish bounding values for hydrologic flow parameters governing fracture transport.

  20. Simulation modeling of the probability of magmatic disruption of the potential Yucca Mountain Site

    SciTech Connect

    Crowe, B.M.; Perry, F.V.; Valentine, G.A.; Wallmann, P.C.; Kossik, R.

    1993-11-01

    The first phase of risk simulation modeling was completed for the probability of magmatic disruption of a potential repository at Yucca Mountain. E1, the recurrence rate of volcanic events, is modeled using bounds from active basaltic volcanic fields and midpoint estimates of E1. The cumulative probability curves for El are generated by simulation modeling using a form of a triangular distribution. The 50% estimates are about 5 to 8 {times} 10{sup 8} events yr{sup {minus}1}. The simulation modeling shows that the cumulative probability distribution for E1 is more sensitive to the probability bounds then the midpoint estimates. The E2 (disruption probability) is modeled through risk simulation using a normal distribution and midpoint estimates from multiple alternative stochastic and structural models. The 50% estimate of E2 is 4.3 {times} 10{sup {minus}3} The probability of magmatic disruption of the potential Yucca Mountain site is 2.5 {times} 10{sup {minus}8} yr{sup {minus}1}. This median estimate decreases to 9.6 {times} 10{sup {minus}9} yr{sup {minus}1} if E1 is modified for the structural models used to define E2. The Repository Integration Program was tested to compare releases of a simulated repository (without volcanic events) to releases from time histories which may include volcanic disruptive events. Results show that the performance modeling can be used for sensitivity studies of volcanic effects.