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Sample records for beneath yucca mountain

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

    International Nuclear Information System (INIS)

    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 δ13C. 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. 15 refs., 4 figs., 1 tab

  2. Seismic reflection evidence against a shallow detachment beneath Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    In 1994, the U.S. Geological Survey (USGS) obtained intermediate-depth seismic reflection profiles across Crater Flat and Yucca Mountain, Nevada. Primary objectives of the seismic profiling were discrimination of the subsurface geometry of faults and imaging of the boundary between the pre-Tertiary sedimentary strata and the Miocene volcanic rocks of Yucca Mountain. Of major interest is the existence and geometry of a postulated west-dipping detachment fault beneath Yucca Mountain. Seismic profiling in the region is hindered by rugged topography; processing of the data is made difficult by complex velocity profiles resulting from sequences of welded and nonwelded volcanic units and their associated variations in physical properties. These reflection profiles provide critical input to efforts to evaluate tectonic models, probabilistic seismic hazards, and potential volcanic hazards near Yucca Mountain, site of investigations for a potential permanent repository for high-level nuclear waste

  3. Yucca Mountain

    International Nuclear Information System (INIS)

    This paper reports on the U.S. Department of Energy's (DOE) office of Civilian Radioactive Waste Management (OCRWM) continuing study of Yucca Mountain, Nevada, to determine the mountain's suitability for isolating high-level nuclear waste. As mandated by the Congress of the United States in the Nuclear Waste Policy Act as amended in 1987, DOE is studying the rocks, climate, and water table at Yucca Mountain to ensure the site is suitable before building a potential repository about 305 meters (1,000 feet) underground. The object of the scientific studies is to determine if Yucca Mountain can isolate solid radioactive materials by using natural barriers, such as the mountain itself--and engineered barriers, such as the waste package container, to isolate the waste

  4. Simulation of flow in the unsaturated zone beneath Pagany Wash, Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    Kwicklis, E.M.; Healy, R.W. [Geological Survey, Lakewood, CO (United States); Flint, A.L. [Geological Survey, Mercury, NV (United States)

    1994-12-31

    A one-dimensional numerical model was created to simulate water movement beneath Pagany Wash, Yucca Mountain, Nevada. Model stratigraphy and properties were based on data obtained from boreholes UE-25 UZ No. 4 and UE-25 UZ No. 5, which was drilled in the alluvial channel and bedrock sideslope of Pagany Wash. Although unable to account for multidimensional or preferential flowpaths beneath the wash, the model proved a useful conceptual tool with which to develop hypotheses and, in some cases, provide bounding calculations. The model indicated that liquid flux decreases with depth in the upper 120 m beneath the wash, with fluxes of several tens mm/yr in the nonwelded base of the Tiva Canyon Member and fluxes on the order of a tenth mm/yr in the upper Topopah Spring Member. Capillary barrier effects were indicated by the model to significantly delay the entry of large fluxes into the potential repository horizon during periods of increasing net infiltration, and to inhibit rapid drainage of water from the nonwelded and bedded intervals into the potential repository horizon during periods of moisture redistribution. Lateral moisture redistribution can be expected to be promoted by these effects.

  5. Simulation of flow in the unsaturated zone beneath Pagany Wash, Yucca Mountain

    International Nuclear Information System (INIS)

    A one-dimensional numerical model was created simulate water movement beneath Pagany Wash, Yucca Mountain, Nevada. Model stratigraphy and properties were on data obtained from boreholes UE-25 UZ number-sign 4 UE-25 UZ number-sign 5, which were drilled in the alluvial channel and bedrock sideslope of Pagany Wash. Although unable to account for multidimensional or preferential flowpaths beneath the wash, the model proved a useful conceptual tool with which to develop hypotheses and, in some cases, provide bounding calculations. The model indicated that liquid flux decreases with depth in the upper 120 m beneath the wash, with fluxes of several tens mm/yr in the nonwelded base of the Tiva Canyon Member and fluxes on the order of a tenth mm/yr in the upper Topopah Spring Member. Capillary barrier effects were indicated by the model to significantly delay the entry of large fluxes into the potential repository horizon during periods of increasing net infiltration, and to inhibit rapid drainage of water from the nonwelded and bedded intervals into the potential repository horizon during periods of moisture redistribution. Lateral moisture redistribution can be expected to be promoted by these effects

  6. Simulation of gas flow beneath Yucca Mountain, Nevada, with a model based on the freshwater head

    International Nuclear Information System (INIS)

    Subsurface gas flow is relevant to the evaluation of the Yucca Mountain, Nevada site as a potential nuclear waste repository. The equations for this flow, formulated in terms of freshwater head, were solved by the finite-difference method using a spreadsheet program on a microcomputer. Cases solved were for current subsurface temperatures and a repository heated by 3, 14, and 30 K. Even a modest temperature increase of 14 to 30 K substantially increases the gas flux to the surface. 19 refs., 8 figs., 3 tabs

  7. A strategy for validation a concept model for radionuclide migration in the saturated zone beneath Yucca Mountain

    International Nuclear Information System (INIS)

    A conceptual model for radionuclide migration in the saturated zone beneath Yucca Mountain is presented. The available hydrologic data from the site is compiled to present a qualitative picture of transport of radionuclides horizontally within the first 100-200 m of the saturated zone. The transport model consists of flow within fractures and interchange of dissolved species between the fractures and surrounding matrix blocks via molecular diffusion. A parametric study illustrates that at the groundwater conditions expected to exist in the saturated zone, radionuclide will have ample time to diffuse fully within the matrix blocks. The result is a predicted solute transport time several orders of magnitude greater than the groundwater travel time (GWTT). To validate this model, a suite of interwell tracer tests are proposed at various flow rates and with conservative and sorbing species. Numerical simulations show that these tests will allow us to discriminate between a matrix diffusion model and a more conventional continuum transport model. (author) 8 figs., tabs., 35 refs

  8. Education and Yucca Mountain

    International Nuclear Information System (INIS)

    This paper outlines a middle school social studies curriculum taught in Nevada. The curriculum was designed to educate students about issues related to the Yucca Mountain project. The paper focuses on the activities used in the curriculum

  9. YUCCA MOUNTAIN SITE DESCRIPTION

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. YUCCA MOUNTAIN SITE DESCRIPTION

    International Nuclear Information System (INIS)

    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

  11. DOE's Yucca Mountain studies

    International Nuclear Information System (INIS)

    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 thinkhigh-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

  12. YUCCA MOUNTAIN PROJECT - A BRIEFING -

    International Nuclear Information System (INIS)

    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

  13. YUCCA MOUNTAIN PROJECT - A BRIEFING --

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. Geology at Yucca Mountain

    International Nuclear Information System (INIS)

    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

  15. Yucca Mountain Project public interactions

    International Nuclear Information System (INIS)

    The US Department of Energy (DOE) is committed to keeping the citizens of Nevada informed about activities that relate to the high-level nuclear waste repository program. This paper presents an overview of the Yucca Mountain Project's public interaction philosophy, objectives, activities and experiences during the two years since Congress directed the DOE to conduct site characterization activities only for the Yucca Mountain site

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

    Energy Technology Data Exchange (ETDEWEB)

    Wesling, J.R.; Bullard, T.F.; Swan, F.H.; Perman, R.C.; Angell, M.M. [Geomatrix Consultants, Inc., San Francisco, CA (United States); Gibson, J.D. [Sandia National Labs., Albuquerque, NM (United States)

    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.

  17. Yearly report, Yucca Mountain project

    International Nuclear Information System (INIS)

    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

  18. Yearly report, Yucca Mountain project

    Energy Technology Data Exchange (ETDEWEB)

    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.

  19. Microbial activity at Yucca Mountain

    International Nuclear Information System (INIS)

    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

  20. Microbial activity at Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. Pyritic ash-flow tuff, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    The Yucca Mountain site is underlain by a 1,500-m-thick Miocene volcanic sequence that comprises part of the southwestern Nevada volcanic field. Rocks of this sequence, which consists mainly of ash-flow tuff sheets with minor flows and bedded tuff, host precious metal mineralization in several areas as near as 10 km from the site. In two such areas, the Bullfrog and Bare Mountain mining districts, production and reserves total over 60 t gold and 150 t silver. Evidence of similar precious metal mineralization at the Yucca Mountain site may lead to mining or exploratory drilling in the future, compromising the security of the repository. The authors believe that most of the pyrite encountered by drilling at Yucca Mountain was introduced as pyroclastic ejecta, rather than by in situ hydrothermal activity. Pyritic ejecta in ash-flow tuff are not reported in the literature, but there is no reason to believe that the Yucca Mountain occurrence is unique. The pyritic ejecta are considered by us to be part of a preexisting hydrothermal system that was partially or wholly destroyed during eruption of the tuff units. Because it was introduced as ejecta in tuff units that occur at depths of about 1,000 m, such pyrite does not constitute evidence of shallow mineralization at the proposed repository site; however, the pyrite may be evidence for mineralization deep beneath Yucca Mountain or as much as tens of kilometers from it

  2. Getting Beyond Yucca Mountain - 12305

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Dickerson, R.P. [Geological Survey, Denver, CO (United States); Drake, R.M. II [Pacific Western Technologies, Ltd., Lakewood, CO (United States)

    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.

  4. Preliminary gravity and magnetic models across Midway Valley and Yucca Wash, Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-12-31

    Detailed gravity and ground magnetic data collected along ten traverses across Midway Valley and Yucca Wash on the eastern flank of Yucca Mountain in southwest Nevada are interpreted. These data were collected as part of an effort to evaluate faulting in the vicinity of proposed surface facilities for a potential nuclear waste repository at Yucca Mountain. Geophysical data show that Midway Valley is bounded by large gravity and magnetic anomalies associated with the Bow Ridge and Paintbrush Canyon faults, on the west side of Exile Hill and on the west flank of Fran Ridge, respectively. In addition, Midway Valley itself is characterized by a number of small-amplitude anomalies that probably reflect small-scale faulting beneath Midway Valley. Gravity and magnetic data across the northwest trending Yucca Wash and the inferred Yucca Wash fault indicate no major vertical offsets greater than 100 m using a density contrast of 0.2 to 0.3 g/cm{sup 3} along the proposed Yucca Wash fault. In addition, a broad magnetic high coincides with the approximate location of the hydrologic gradient and probably reflects moderately magnetic Topopah Spring Tuff or lavas in the Calico Hills Formation.

  5. Preliminary gravity and magnetic models across Midway Valley and Yucca Wash, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Detailed gravity and ground magnetic data collected along ten traverses across Midway Valley and Yucca Wash on the eastern flank of Yucca Mountain in southwest Nevada are interpreted. These data were collected as part of an effort to evaluate faulting in the vicinity of proposed surface facilities for a potential nuclear waste repository at Yucca Mountain. Geophysical data show that Midway Valley is bounded by large gravity and magnetic anomalies associated with the Bow Ridge and Paintbrush Canyon faults, on the west side of Exile Hill and on the west flank of Fran Ridge, respectively. In addition, Midway Valley itself is characterized by a number of small-amplitude anomalies that probably reflect small-scale faulting beneath Midway Valley. Gravity and magnetic data across the northwest trending Yucca Wash and the inferred Yucca Wash fault indicate no major vertical offsets greater than 100 m using a density contrast of 0.2 to 0.3 g/cm3 along the proposed Yucca Wash fault. In addition, a broad magnetic high coincides with the approximate location of the hydrologic gradient and probably reflects moderately magnetic Topopah Spring Tuff or lavas in the Calico Hills Formation

  6. Preliminary mapping of surficial geology of Midway Valley Yucca Mountain Project, Nye County, Nevada

    International Nuclear Information System (INIS)

    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

  7. Site characterization at Yucca Mountain

    International Nuclear Information System (INIS)

    The Yucca Mountain site, located in south-central Nevada, has recently gained a central position in the US geologic repository program. The goal of the repository is to protect the safety and health of the public for a period of 10,000 yr. The data-base and confidence levels must be developed in a manner consistent with this goal. However, there are no standard criteria that can be used to determine the confidence level required for a given parameter in order to ensure public health and safety. This is in part due to the interdependence of many of the site parameters important to repository performance. The process for refining confidence levels must be iterative in that performance and design analyses can initially be used as a screening tool to eliminate parameters from consideration if they can be shown to have little or no potential impact on repository performance. The parameters required to predict the range of variation in geologic conditions that is likely over the next 10,000 yr and the information necessary to estimate the probabilities of catastrophic geologic events must be obtained and utilized in continued performance and design analyses. Further sensitivity studies utilizing the improved data base can then be conducted and confidence levels for key geotechnical parameters can be refined

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  9. Mechanical excavator performance in Yucca Mountain tuffs

    International Nuclear Information System (INIS)

    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

  10. Yucca Mountain biological resources monitoring program

    International Nuclear Information System (INIS)

    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 ampersand G Energy Measurements, Inc. (EG ampersand 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

  11. Yucca Mountain Biological Resources Monitoring Program

    International Nuclear Information System (INIS)

    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

  12. Weapons test seismic investigations at Yucca Mountain

    International Nuclear Information System (INIS)

    Yucca Mountain, located on and adjacent to the Nevada Test Site, is being characterized as part of an ongoing effort to identify a potential high-level nuclear waste repository. This site will be subjected to seismic ground motions induced by underground nuclear explosions. A knowledge of expected ground motion levels from these tests will enable the designers to provide for the necessary structural support in the designs of the various components of the repository. The primary objective of the Weapons Test Seismic Investigation project is to develop a method to predict the ground motions expected at the repository site as a result of future weapons tests. This paper summarizes the data base presently assembled for the Yucca Mountain Project, characteristics of expected ground motions, and characterization of the two-dimensional seismic properties along paths between Yucca Mountain and the testing areas of the Nevada Test Site

  13. Nuclear waste disposal: Gambling on Yucca Mountain

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  16. Evidence for Gropun-Water Stratification Near Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-03-24

    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.

  17. Seismic design considerations for active faulting at Yucca Mountain, NV

    International Nuclear Information System (INIS)

    This paper explores the seismic hazard concerns at Yucca Mountain, NV that implicitly results from near field vibratory ground motion, fault displacement within the proposed repository block and the complexity that these two issues add to the siting and licensing process. Three major zones or belts of contemporary regional seismicity intersect in the Yucca Mountain, NV area, the proposed site for the nation's first high-level radioactive waste repository. Within a 1,000 sq. km area of the Yucca Mountain site, there are 32 known faults with demonstrated or suggested Quaternary displacements. Holocene displacement is evident on three of the faults. The maximum magnitude earthquake for the site is estimated to be somewhere between M 6.5--7.0. Free field peak ground acceleration from a maximum magnitude earthquake is estimated to range from 0.4--1.0 g. The maximum magnitude earthquake and resultant acceleration from movement on surface faults within the proposed repository block or on buried faults beneath the site without clear surface expression are estimated to be in the same range or larger. Due to the paucity of historical strong motion data recorded for near field earthquakes, estimate of potential ground motion and fault displacement effects within the repository block are extremely speculative

  18. Characterize Eruptive Processes at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    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

  19. Characterize Eruptive Processes at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Ponce, D.A.; Langenheim, V.E. [Geological Survey, Menlo Park, CA (United States)

    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.

  2. TBM tunneling on the Yucca Mountain Project

    International Nuclear Information System (INIS)

    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

  3. Predicting the Future at Yucca Mountain

    International Nuclear Information System (INIS)

    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

  4. DRIFT SCALE TEST THE YUCCA MOUNTAIN PROJECT

    International Nuclear Information System (INIS)

    The mission for the Department of Energy's Office of Civilian Radioactive Waste Management is to safely manage and dispose of the nation's spent nuclear fuel and high level radioactive waste in a geologic repository. A potential site at Yucca Mountain in Nevada is being studied by the DOE. Nuclear waste is to be contained in packages which will be emplaced in the repository for thousands of years. After these manmade packages eventually degrade, the repository should continue to isolate nuclear waste from the environment. The repository is to comply with the 1982 Nuclear Waste Policy Act and its amendments. Also, the health and safety of the workers will not be compromised during the construction and operation of the repository. To investigate important technical issues inherent with the construction, operation, closure, and performance of the repository, a series of in situ experiments have been planned for the Exploratory Studies Facility (ESF) located inside Yucca Mountain. The ESF Thermal Test is an integral part of the Site Characterization Plan developed in 1988 following the Congressional mandate to evaluate only Yucca Mountain as a potential repository. The planning documented in the Site Characterization Program has evolved to include the construction of the ESF to accommodate changing needs and increased understanding of the Yucca Mountain Project. The recently updated ESF thermal testing strategy includes the Drift Scale Test (DST). The DST is more complex, longer duration and larger-scale than its predecessor--the Single Heater Test. The primary purpose of the DST is to acquire a more in-depth understanding of the coupled thermal-mechanical-hydrological-chemical processes anticipated in the rock mass surrounding the proposed repository

  5. Rural migration decision relating to Yucca Mountain

    International Nuclear Information System (INIS)

    Individual and family migration decisions were assessed to ascertain the degree to which the siting of the proposed Yucca Mountain repository would influence decisions to remain, leave, or leave and return to the region. Data collected in Lincoln and Nye Counties in Nevada were used. The results of the two studies show that there is little or no impact of the proposed repository on residential choice decisions

  6. Yucca Mountain Project Surface Facilities Design

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. The Yucca Mountain Project Prototype Testing Program

    International Nuclear Information System (INIS)

    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

  8. Yucca Mountain Site characterization project bibliography, January--June 1991

    International Nuclear Information System (INIS)

    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 Science and Technology Database from January 1, 1990, through December 31, 1991

  9. Yucca Mountain Task 4, Final report FY 1993

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. Yucca Mountain Project bibliography, 1988--1989

    International Nuclear Information System (INIS)

    This bibliography contains information on the Yucca Mountain Project that was added to the Department of Energy's Energy Data Base from January 1988 through December 1989. This supplement also includes a new section which provides information about publications on the Energy Data Base that were not sponsored by the project but have some relevance to it. The bibliography is categorized by principal project participating organization. Participant-sponsored subcontractor reports, papers, and articles are included in the sponsoring organization's list. Indexes are provided for Corporate Author, Personal Author, Subject, Contract Number, Report Number, Order Number Correlation, and Key Word in Context. All entries in the Yucca Mountain Project 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). Technical reports on the Yucca Mountain Project are on display in special open files at participating Nevada Libraries and in the Public Document Room of the US Department of Energy, Nevada Operations Office, in Las Vegas

  11. Seismic design methodology for a geologic repository at Yucca Mountain

    International Nuclear Information System (INIS)

    This paper is a summary of the topical report which describes the methodology that the Department of Energy (DOE) plans to use for the preclosure seismic design of the potential geologic repository at Yucca Mountain. The topical report summarized is the second of three topical reports on seismic assessment and design for Yucca Mountain. Four seismic safety performance categories for seismic design of Yucca Mountain are identified and linked to accepted seismic codes and practices. The methodology and criteria that DOE is proposing to use to design the Yucca Mountain systems, structures, and components for fault displacement is also summarized

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

    International Nuclear Information System (INIS)

    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 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

  13. Monitoring the vadose zone in fractured tuff, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Unsaturated tuff beneath Yucca Mountain, Nevada, is being evaluated by the US Department of Energy as a host rock for a potential repository for high-level radioactive waste. As part of the Nevada Nuclear Waste Storage Investigations Project of the US Department of Energy, the US Geological Survey has been conducting hydrologic, geologic, and geophysical investigations at Yucca Mountain and the surrounding region to provide data evaluation of the potential suitability of the site. Hydrologic investigations of the unsaturated zone at this site were started in 1982. A 17.5-inch- (44.5-centimeter-) diameter borehole (USW UZ-1) was drilled by the reverse-air vacuum-drilling technique to a depth of 1269 feet (387 meters). This borehole was instrumented at 33 depth levels. At 15 of the levels, 3 well screens were embedded in coarse-sand columns. The sand columns were isolated from each other by thin layers of bentonite, columns of silica flour, and isolation plugs consisting of expansive cement. Thermocouple psychrometers and pressure transducers were installed within the screens and connected to the data-acquisition system at the land surface through thermocouple and logging cables. Two of the screens at each level were equipped with access tubes to allow collection of pore-gas samples. In addition to these instruments, 18 heat-dissipation probes were installed within the columns of silica flour, some of which also had thermocouple psychrometers. 20 refs., 13 figs., 2 tabs

  14. Tunneling progress on the Yucca Mountain Project

    International Nuclear Information System (INIS)

    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

  15. Archaeological program for the Yucca Mountain Site

    International Nuclear Information System (INIS)

    Archaeological surveys, limited surface collections and selected test excavations in the Yucca Mountain Project Area have revealed four distinct aboriginal hunting and gathering adaptive strategies and a separate historic Euroamerican occupation. The four aboriginal adaptations are marked by gradual shifts in settlement locations that reflect changing resource procurement strategies. Whereas the earliest hunters and gatherers focused their activities around the exploitation of toolstone along ephemeral drainages and the hunting of game animals in the uplands, the latest aboriginal settlements reflect intensive procurement of early spring plant resources in specific upland environments. The final Euroamerican occupation in the area is marked by limited prospecting activities and travel through the area by early immigrants

  16. Overview of the Yucca Mountain Licensing Process

    International Nuclear Information System (INIS)

    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

  17. Regional groundwater modeling of the saturated zone in the vicinity of Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Results of groundwater modeling of the saturated zone in the vicinity of Yucca Mountain are presented. Both a regional (200 x 200 km) and subregional (50 x 50 km) model were used in the analyses. Simulations were conducted to determine the impact of various disruptive that might take place over the life span of a proposed Yucca Mountain geologic conditions repository on the groundwater flow field, as well as changes in the water-table elevations. These conditions included increases in precipitation and groundwater recharge within the regional model, changes in permeability of existing hydrogeologic barriers, a:nd the vertical intrusion of volcanic dikes at various orientations through the saturated zone. Based on the regional analysis, the rise in the water-table under Yucca Mountain due to various postulated conditions ranged from only a few meters to 275 meters. Results of the subregional model analysis, which was used to simulate intrusive dikes approximately 4 kilometers in length in the vicinity of Yucca Mountain, showed water-table rises ranging from a few meters to as much as 103 meters. Dikes oriented approximately north-south beneath Yucca Mountain produced the highest water-table rises. The conclusions drawn from this analysis are likely to change as more site-specific data become available and as the assumptions in the model are improved

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

    Science.gov (United States)

    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.

  19. Magma Dynamics at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    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

  20. The Yucca Mountain standard: Proposals for leniency

    International Nuclear Information System (INIS)

    The proposed geologic repository at Yucca Mountain, Nevada, for spent nuclear fuel and other highly radioactive waste needs an official standard to protect the public from release of radioactivity. Standards proposed by the US Congress, the nuclear industry (NEI), the Electric Power Research Institute (EPRI), the Department of Energy (DOE), and the TYMS Committee of the National Research Council (NRC) are reviewed. Each of these proposals would introduce a degree of leniency not heretofore experienced in radiation protection. No adequate scientific justification is presented. Some scientifically invalid proposals are said to be justified on the grounds of policy. Most leading industrial nations are designing geologic repositories to meet the traditional criteria for safety and for protecting public health, including quantitative calculations of doses for the periods when significant doses can occur, rather than stopping calculations at 10,000 years as many in the US would have us do. There is no evidence that they are seriously seeking more lenient standards for public health protection. The US has the resources and skills to protect future people from waste with the same care that it now protects the public from radiation. The Yucca Mountain project will be seriously damaged if it is directed to depart from the traditional conservative criteria for determining safety and protection of public health, criteria that are adopted in other countries working on geologic disposal

  1. Total system performance assessment for Yucca Mountain

    International Nuclear Information System (INIS)

    As part of the U.S. Department of Energy's evaluation of site suitability for a potential high-level radioactive waste repository, the long-term behavior of the mined geologic disposal system must be determined. This determination requires a knowledge of the characteristics of the present natural system, waste-package and engineered-system designs, a description of the environment around the emplacement zone, and descriptions of possible perturbations that may affect the nature of the engineered and natural systems. In 1991, participants in the Yucca Mountain Site Characterization Project completed a preliminary assessment of the likely performance of a potential repository at Yucca Mountain, Nevada. This preliminary assessment evaluated aqueous and gaseous flow, future climatic conditions, and disturbances to the system by basaltic volcanism and inadvertent human intrusion. A second total system performance evaluation is currently in progress. This second iteration is building on the previous analyses in a number of ways. More recent site characterization information and a much more complex model representing the source term are being incorporated. Multiple waste package designs, emplacement modes, and areal power densities are being analyzed. (author)

  2. Magma Dynamics at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Yucca Mountain drift scale test progress report

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. Restructured site characterization program at Yucca Mountain

    International Nuclear Information System (INIS)

    During 1994 and the early part of 1995, the US Department of Energy's Yucca Mountain Site Characterization Office (YMSCO) and its parent organization, the Office of Civilian Radioactive Waste Management (OCRWM) underwent a significant restructuring. Senior Department officials provided the leadership to reorient the management, technical, programmatic, and public interaction approach to the US High Level Radioactive Waste Disposal Program. The restructuring involved reorganizing the federal staff, conducting meaningful strategic planning, improving the management system, rationalizing contractor responsibilities, focusing upon major products, and increasing stakeholder involvement. The restructured program has prioritized technical and scientific activities toward meeting major regulatory milestones in a timely and cost-effective manner. This approach has raised concern among elements of technical, scientific, and oversight bodies that suitability and licensing decisions could be made without obtaining sufficient technical information for this first-of-its-kind endeavor. Other organizations, such as congressional committees, industrial groups, and rate payers believe characterization goals can be met in a timely manner and within the limitation of available funds. To balance these contrasting views in its decision making process, OCRWM management has made a special effort to communicate its strategy to oversight bodies, the scientific community and other stakeholders and to use external independent peer review as a key means of demonstrating scientific credibility. Site characterization of Yucca Mountain in Nevada is one of the key elements of the restructured program

  5. Using science soundly: The Yucca Mountain standard

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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

  8. Preparing the Yucca Mountain Multimedia Presentation

    International Nuclear Information System (INIS)

    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

  9. Preparing the Yucca Mountain Multimedia Presentation

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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

  11. Interface management for the Yucca Mountain Project

    International Nuclear Information System (INIS)

    The subject of this report is selection of that portion of physical and informational interfaces that need to be controlled on the Yucca Mountain Project (YMP). Physical interfaces are interactions between physical elements of the mined geologic disposal system; for example, the repository shafts will interface with the shafts in the Exploratory Shaft Facility (ESF), because the ESF shafts will eventually be absorbed into the repository as additional repository shafts. Informational interfaces are interactions involving an exchange of information between organizations working on the mined geologic disposal system; for example, the in situ testing contractor will interact with the site performance assessment contractor and will supply information regarding host rock behavior. This report describes the physical system interfaces that can be identified from analysis of a physical system structure. A discussion of informational interfaces can be found elsewhere. 30 refs., 8 figs., 3 tabs

  12. Regulatory assessment of evapotranspiration at Yucca Mountain

    International Nuclear Information System (INIS)

    Under the U.S. Nuclear Regulatory Commission's (NRC) siting criteria for a high-level waste (HLW) repository (10 CFR Part 60.122), one of the favorable conditions refers to a climatic regime where average annual historic precipitation is a small percentage of the average annual potential evapotranspiration (PET). A license application for the Yucca Mountain site will need to demonstrate whether or not this favorable condition is present. This paper describes the technical basis for a newly developed review plan on this topic. The review plan will be published in NRC's License Application Review Plan, and will therefore be available for public review and comment. We present this information recognizing that the Congress is currently considering changes in how a HLW repository will be licensed

  13. Environmental radiation protection standards for Yucca Mountain

    International Nuclear Information System (INIS)

    The Environmental Protection Agency (EPA) has been given the responsibility of setting site-specific health and safety standards for the potential repository at Yucca Mountain, Nevada. The same legislation that gave the Agency that responsibility, mandated a study by the National Academy of Sciences (NAS) to provide input into the bases for the EPA standards. The NAS has completed and presented a report to the Agency; this paper summarizes the report's recommendations and conclusions. Following receipt of the report, the Agency opened a comment period and held public meetings to gather comments; the major issues from the comments are summarized. Based upon the report from NAS and the public comments, EPA has started formulating proposed standards which will be known as 40 CFR Part 197. It is planned for the proposal of 40 CFR Part 197 to occur in the summer of 1996

  14. Tectonic and neotectonic framework of the Yucca Mountain Region

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. Characterize Eruptive Processes at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    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

  16. Characterize Eruptive Processes at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    International Nuclear Information System (INIS)

    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)

  18. Yucca Mountain, a high-level nuclear waste repository over a billion barrel oil field?

    International Nuclear Information System (INIS)

    New structural models and source rock data suggest that the proposed Yucca Mountain, Nevada, high-level nuclear waste repository lies in the Central Nevada thrust belt. The Central Nevada thrust belt could contain billion-barrel oil fields. The Central Nevada thrust belt coincides with an organic richness fairway and a maturation fairway of Mississippian source rocks that have already produced more than 25 million barrels of oil. Giant thrust-related structures along the thrust belt have yet to be tested. However, new work in the Tempahute Range, which lies between Yucca Mountain and the prolific Grant Canyon field, confirms the thrust belt concept and sheds light on source and reservoir rock quality and thrust belt geometry. Klippen of overmature Mississippian rocks are distinct on maturation maps such as the Diamond Range klippe in central Nevada. Thrust trends suggest that the Eleana Range near Yucca Mountain may be another klippe of overmature rocks over Mississippian source rocks in the oil window. There is a strong possibility that the subthrust source rocks may have generated large quantities of hydrocarbons that may be trapped in large thrust features beneath Yucca Mountain

  19. Numerical studies of rock-gas flow in Yucca Mountain; Yucca Mountain Site Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Ross, B.; Amter, S.; Lu, Ning [Disposal Safety, Inc., Washington, DC (United States)

    1992-02-01

    A computer model (TGIF -- Thermal Gradient Induced Flow) of two-dimensional, steady-state rock-gas flow driven by temperature and humidity differences is described. The model solves for the ``fresh-water head,`` a concept that has been used in models of variable-density water flow but has not previously been applied to gas flow. With this approach, the model can accurately simulate the flows driven by small differences in temperature. The unsaturated tuffs of Yucca Mountain, Nevada, are being studied as a potential site for a repository for high-level nuclear waste. Using the TGIF model, preliminary calculations of rock-gas flow in Yucca Mountain are made for four east-west cross-sections through the mountain. Calculations are made for three repository temperatures and for several assumptions about a possible semi-confining layer above the repository. The gas-flow simulations are then used to calculate travel-time distributions for air and for radioactive carbon-14 dioxide from the repository to the ground surface.

  20. BIOSPHERE MODELING AT YUCCA MOUNTAIN, NEVADA

    International Nuclear Information System (INIS)

    The objectives of the biosphere modeling efforts are to assess how radionuclides potentially released from the proposed repository could be transported through a variety of environmental media. The study of these transport mechanisms, referred to as pathways, is critical in calculating the potential radiation dose to man. Since most of the existing and pending regulations applicable to the Project are radiation dose based standards, the biosphere modeling effort will provide crucial technical input to support the Viability Assessment (VA), the Working Draft of License Application (WDLA), and the Environmental Impact Statement (EIS). In 1982, the Nuclear Waste Policy Act (NWPA) was enacted into law. This federal law, which was amended in 1987, addresses the national issue of geologic disposal of high-level nuclear waste generated by commercial nuclear power plants, as well as defense programs during the past few decades. As required by the law, the Department of Energy (DOE) is conducting a site characterization project at Yucca Mountain, Nevada, approximately 100 miles northwest of Las Vegas, Nevada, to determine if the site is suitable for the nation's first high-level nuclear waste repository

  1. Preliminary conceptual model for mineral evolution in Yucca Mountain

    International Nuclear Information System (INIS)

    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 aSiO2(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+ and CO32-. 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

  2. Preliminary conceptual model for mineral evolution in Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Regulatory compliance for a Yucca Mountain repository. A performance assessment perspective

    International Nuclear Information System (INIS)

    The U.S. Department of Energy's Yucca Mountain Site Characterization Project is scheduled to submit a License Application in the year 2002. Some insights are provided 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 requirements of a proper standard are discussed. (author)

  4. Estimates of ambient groundwater velocity in the alluvium south of Yucca Mountain from single-well tracer tests

    International Nuclear Information System (INIS)

    The saturated alluvium located south of Yucca Mountain, Nevada is expected to serve as the final barrier to radionuclide transport from the proposed high-level nuclear waste repository at Yucca Mountain. The alluvium will act as a barrier if radionuclides breach the engineered barriers in the repository, move through the unsaturated zone beneath the repository to the water table, and then migrate through saturated volcanic tuffs to the alluvium. Three single-well injection-withdrawal tracer tests were conducted between December 2000 and April 2001 in the saturated alluviuni at NC-EWDP-19D1, a Nye County-Early Warning Drilling Program well located about 18 km south of Yucca Mountain. The tests had the objectives of (1) distinguishing between a single- and a dual-porosity conceptual radionuclide transport model for the alluvium, and (2) obtaining estimates of ambient groundwater velocity in the alluvium.

  5. Tectonic stability and expected ground motion at Yucca Mountain

    International Nuclear Information System (INIS)

    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

  6. Yucca Mountain Project bibliography, January--June 1989

    International Nuclear Information System (INIS)

    Following a reorganization of the Office of Civilian Radioactive Waste Management, 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 1990 through June 1990. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  8. Neptunium retardation with tuffs and groundwaters from Yucca Mountain

    International Nuclear Information System (INIS)

    The retardation of neptunium was studied using batch sorption and column techniques. Pure mineral separates, tuffs and groundwaters from Yucca Mountain were used for these experiments. Our results indicate that Np sorption increases rapidly as the pH of the water increases in cases where surface complexation is thought w be the dominant sorption mechanism. Oxide minerals (such as hematite) sorb Np strongly; therefore, these minerals even at trace levels in Yucca Mountain tuffs can result in significant Np retardation. Neptunium in groundwaters from Yucca Mountain exhibited a significant amount of sorption onto quartz. Neptunium sorption onto quartz is important because of the large quantity of silica in the tuffs. Elution of neptunium solutions in groundwater through columns made of crushed tuff yielded sorption coefficients that agree with the sorption results obtained using batch sorption techniques. Agreement between batch and column experiments indicates a neptunium sorption mechanism that is linear, reversible, and instantaneous

  9. Native American plant resources in the Yucca Mountain Area, Nevada

    International Nuclear Information System (INIS)

    This report presents Native American interpretations of and concerns for plant resources on or near Yucca Mountain, Nevada. This one of three research reports regarding Native American cultural resources that may be affected by site characterization activities related to the Yucca Mountain high-level radioactive waste disposal facility. Representatives of the sixteen involved American Indian tribes identified and interpreted plant resources as part of a consultation relationship between themselves and the US Department of Energy (DOE). Participants in the ethnobotany studies included botanists who have conducted, and continue to conduct, botanical studies for the Yucca Mountain Project. This report is to be used to review research procedures and findings regarding the process of consulting with the sixteen tribes, interviews with tribal plant specialists and elders, and findings from the ethnobotanical visits with representatives of the sixteen tribes. An annual report will include a chapter that summarizes the key findings from this plant resources study. 23 refs., 75 figs., 39 tabs

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  11. Yucca Mountain Site characterization project bibliography, January--June 1992

    International Nuclear Information System (INIS)

    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 June 30, 1992. The bibliography is categorized by principal project participating organization. Participant-sponsored subcontractor resorts, 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

  12. Suggested considerations for EPA's Yucca Mountain repository radiation protection standard

    International Nuclear Information System (INIS)

    Among factors that the State of Nevada believes EPA should consider in promulgating a site specific radiation protection standard for a potential Yucca Mountain, Nevada, high-level nuclear waste repository are the following: (1) the standard should be relevant to the Yucca Mountain site, not driven by DOE's Yucca Mountain Project and its perceived data needs; (2) there should be a baseline evaluation of the best protection that current technology can provide; (3) ALARA should be a required demonstration, at least as it relates to thermal loading; (4) any dose standard set should include both individual and population dose limits; and, (5) any standard should take into account the potential additional radionuclide contamination in the area due to activities at the Nevada Test Site and Beatty low-level radioactive waste disposal site

  13. Yucca Mountain Site Characterization Project Bibliography, July--December 1990

    International Nuclear Information System (INIS)

    Following a reorganization of the Office of Civilian Radioactive Waste Management, the Yucca Mountain Project was renamed Yucca Mountain Site Characterization Project. The title of this bibliography was also changed to Yucca Mountains 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 July 1990 through December 1990. The bibliography is categorized by principal project participating organization. Participant-sponsored subcontractor reports, papers and articles are included in the sponsoring organizations 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

  14. The vegetation of Yucca Mountain: Description and ecology

    International Nuclear Information System (INIS)

    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

  15. The vegetation of Yucca Mountain: Description and ecology

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  16. Yucca Mountain Site characterization project bibliography, January--June 1991

    International Nuclear Information System (INIS)

    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 1991 through June 1991. 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

  17. Yucca Mountain Site Characterization Project bibliography, January--June 1992

    International Nuclear Information System (INIS)

    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, 1993, through June 30, 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

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

    International Nuclear Information System (INIS)

    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 ( than about 7 x 10-8 events yr-1 . Simple probability estimates are used to assess possible implications of not drilling aeromagnetic anomalies in the Amargosa Valley. The sensitivity of the disruption probability to the location of northeast boundaries of volcanic zones near the Yucca Mountain sit

  19. Modeling fluid-rock interaction at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    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

  20. Revised poteniometric-surface map, Yucca Mountain and vicinity, Nevada

    International Nuclear Information System (INIS)

    This report presents a revised potentiometric-surface map based mainly on the 1988 average water levels at Yucca Mountain and the nearby vicinity extending from Crater Flat to Jackass Flats. Discussion includes an explanation of the revised potentiometric-surface map, an examination of yearly trends in the water levels, and adjustments for temperature and density effects in the deeper wells. Report scope focuses on the potentiometric surface of the uppermost saturated zone in the Tertiary volcanic rocks at Yucca Mountain. Some information, related to the underlying Paleozoic carbonate aquifer, pertinent to the volcanic flow system, is presented

  1. Basaltic volcanic episodes of the Yucca Mountain region

    International Nuclear Information System (INIS)

    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

  2. Sustaining native microbial growth with endogenous nutrients at Yucca Mountain

    International Nuclear Information System (INIS)

    The integrity of candidate waste package materials for the proposed Yucca Mountain (YM) repository may be compromised by the corrosive activities of microorganisms. Bacterial activities will be dependent on the abilities of deleterious bacteria to grow and multiply in the repository environment. Therefore, preliminary to assessing microbial induced corrosion, experiments were undertaken to determine the growth of native YM bacterial communities in modified YM pore water. Specifically, we sought to define nutrients that limit bacterial growth in Yucca Mountain and determine growth rates under aerobic, saturated conditions

  3. Yucca Mountain student tours: Response, reactions, and results

    International Nuclear Information System (INIS)

    In March of 1991, the Yucca Mountain Site Characterization Project (YMP) began providing monthly tours for the general public to visit the Yucca Mountain site. The goal of these tours has been to inform the public and to provide direct contact to Project scientists. An overwhelming response has since created a need for expansion of the tour program to meet community demands. This paper describes the development, implementation, and results of the grade 6-12 tour program introduced in the last year to meet the needs of the educational community in particular

  4. An assessment of future volcanic hazard at Yucca Mountain

    International Nuclear Information System (INIS)

    Preliminary results and methods of a volcanic-hazards assessment for the proposed high-level nuclear-waste repository at Yucca Mountain are given. The most significant hazards are potential intersection of the repository by a basaltic dike, or structural disruption associated with dike intrusion. Two approaches are taken, which give similar results: homogeneous volcanic-source zones and spatial smoothing. The preliminary computed probabilities of intersection of the Yucca Mountain repository by a basaltic dike are in the range 10-7 to 10-8 per year

  5. Preparing to Submit a License Application for Yucca Mountain

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Ozdemir, L.; Gertsch, L.; Neil, D.; Friant, J. [Colorado School of Mines, Golden, CO (United States). Earth Mechanics Inst.

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  8. Yucca Mountain transportation routes: Preliminary characterization and risk analysis

    International Nuclear Information System (INIS)

    This report presents appendices related to the preliminary assessment and risk analysis for high-level radioactive waste transportation routes to the proposed Yucca Mountain Project repository. Information includes data on population density, traffic volume, ecologically sensitive areas, and accident history

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

    International Nuclear Information System (INIS)

    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

  10. The status of Yucca Mountain site characterization activities

    International Nuclear Information System (INIS)

    The U.S. Department of Energy (DOE) Office of Civilian Radioactive Waste Management is continuing its studies to determine if Yucca Mountain in Nevada can safely isolate high-level nuclear waste for the next ten thousand years. As mandated by Congress in 1987, DOE is studying the rocks, the climate, and the water table at Yucca Mountain to ensure that the site is suitable before building a repository about 305 meters (1,000 feet) below the surface. Yucca Mountain, located 161 kilometers (100 miles) northwest of Las Vegas, lies on the western edge of the Nevada Test Site. Nevada and DOE have been in litigation for almost two years over three environmental permits needed to conduct studies, but recent court decisions have allowed limited work to take place. This paper will examine progress made on the Yucca Mountain Site Characterization Project (YMP) during the past year and continuing into 1992, discuss the complex legal issues that are delaying progress, and describe new site drilling work. Title I and II design work on the underground exploratory studies facility (ESF) also will be discussed

  11. Natural gels in the Yucca Mountain Area, Nevada, USA

    International Nuclear Information System (INIS)

    Relict gels at Yucca Mountain include pore- and fracture-fillings of silica and zeolite related to diagenetic and hydrothermal alternation of vitric tuffs. Water-rich free gels in fractures at Rainier Mesa consist of smectite with or without silica-rich gel fragments. Gels are being studied for their potential role in transport of radionuclides from a nuclear-waste repository

  12. The appropriateness of one-dimensional Yucca Mountain hydrologic calculations

    International Nuclear Information System (INIS)

    This report brings into focus the results of numerous studies that have addressed issues associated with the validity of assumptions which are used to justify reducing the dimensionality of numerical calculations of water flow through Yucca Mountain, NV. it is shown that, in many cases, one-dimensional modeling is more rigorous than previously assumed

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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

  18. THE PROPOSED YUCCA MOUNTAIN REPOSITORY FROM A CORROSION PERSPECTIVE

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

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

  20. TBM tunneling on the Yucca Mountain Project: Proceedings

    International Nuclear Information System (INIS)

    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

  1. Distribution and nutrient limitations of heterotrophic bacteria from Yucca Mountain

    International Nuclear Information System (INIS)

    Microbiota have been recovered from diverse deep subsurface environments, including rock strata similar to those found in Yucca Mountain. Microbial processes have been shown to accelerate the corrosion of structural materials, alter rock substrates through biogeochemical cycling and production of metabolites, and may influence the transport of radionuclides. A deep subsurface geological repository has been proposed for the long-term storage of high-level nuclear waste and this presents a challenge to model the long-term stability of a such a facility, with regards to microbial abundance, distribution and activity. The aims of this research were to (1) gather background data concerning the numbers and distribution of bacteria indigenous to Yucca Mountain, (2) determine nutrient limitations of indigenous bacteria, and (3) collect isolates for further investigation. The information gleaned will be crucial to the determination of the impact of microbiota on repository integrity

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Nine-component vertical seismic profiling at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Nine-component vertical seismic profiling has been conducted at the UE-25 UZ No. 16 borehole at Yucca Mountain, Nevada, in support of investigation of the hydrologic significance of fault and fracture systems. A large data set from multi-component sources and receivers allows state-of-the-art advances in processing using polarization filtering and reverse time migration, for enhanced interpretation of geologic features

  4. Scientific issues and public interactions: The Yucca Mountain project

    International Nuclear Information System (INIS)

    This report provides a review of impressions obtained from public interactions regarding the risk of volcanism for underground storage of radioactive waste. These impressions were gained through participation in numerous contacts for the Yucca Mountain Site Characterization Project during the last six years. A conclusion emerging from public interactions is that scientists and those responsible for policy decisions must become more familiar with risk assessment, risk communication, and the requirements of objectively examining decision options for defining acceptable risk

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  6. Yucca Mountain Project bibliography, January--June 1989

    International Nuclear Information System (INIS)

    This update contains information on the Yucca Mountain Project that was added to the Energy Data Base (EDB) during the first six months of 1989. Prior to August 5, 1988, this project was called the Nevada Nuclear Waste Storage Investigations. The update is categorized by principal project participant organizations, and items are arranged in chronological order according to publication date. Participant-sponsored subcontractor reports, meeting papers, and journal articles are included with sponsoring organization

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

    International Nuclear Information System (INIS)

    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

  8. Modeling heterogeneous unsaturated porous media flow at Yucca Mountain

    International Nuclear Information System (INIS)

    Geologic systems are inherently heterogeneous and this heterogeneity can have a significant impact on unsaturated flow through porous media. Most previous efforts to model groundwater flow through Yucca Mountain have used stratigraphic units with homogeneous properties. However, modeling heterogeneous porous and fractured tuff in a more realistic manner requires numerical methods for generating heterogeneous simulations of the media, scaling of material properties from core scale to computational scale, and flow modeling that allows channeling. The Yucca Mountain test case of the INTRAVAL project is used to test the numerical approaches. Geostatistics is used to generate more realistic representations of the stratigraphic units and heterogeneity within units is generated using sampling from property distributions. Scaling problems are reduced using an adaptive grid that minimizes heterogeneity within each flow element. A flow code based on the dual mixed-finite-element method that allows for heterogeneity and channeling is employed. In the Yucca Mountain test case, the simulated volumetric water contents matched the measured values at drill hole USW UZ-16 except in the nonwelded portion of Prow Pass

  9. Surfaced-based investigations plan, Volume 4: Yucca Mountain Project

    International Nuclear Information System (INIS)

    This document represents a detailed summary of design plans for surface-based investigations to be conducted for site characterization of the Yucca Mountain site. These plans are current as of December 1988. The description of surface-based site characterization activities contained in this document is intended to give all interested parties an understanding of the current plans for site characterization of Yucca Mountain. The maps presented in Volume 4 are products of the Geographic Information System (GIS) being used by the Yucca Mountain Project. The ARC/INFO GIS software, developed by Environmental Systems Research Institute, was used to digitize and process these SBIP maps. The maps were prepared using existing US Geological Survey (USGS) maps as a planimetric base. Roads and other surface features were interpreted from a variety of sources and entered into the GIS. Sources include the USGS maps, 1976 USGS orthophotoquads and aerial photography, 1986 and 1987 aerial photography, surveyed coordinates of field sites, and a combination of various maps, figures, descriptions and approximate coordinates of proposed locations for future activities

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

  12. Modeling heterogeneous unsaturated porous media flow at Yucca Mountain

    International Nuclear Information System (INIS)

    Geologic systems are inherently heterogeneous and this heterogeneity can have a significant impact on unsaturated flow through porous media. Most previous efforts to model groundwater flow through Yucca Mountain have used stratigraphic units with homogeneous properties. However, modeling heterogeneous porous and fractured tuff in a more realistic manner requires numerical methods for generating heterogeneous simulations of the media, scaling of material properties from core scale to computational scale, and flow modeling that allows channeling. The Yucca Mountain test case of the INTRAVAL project is used to test the numerical approaches. Geostatistical methods are used to generate more realistic representations of the stratigraphic units and heterogeneity within units is generated using sampling from property distributions. Scaling problems are reduced using an adaptive grid that minimizes heterogeneity within each flow element. A flow code based on the dual mixed-finite-element method that allows for heterogeneity and channeling is employed. In the Yucca Mountain test case, the simulated volumetric water contents matched the measured values at drill hole USW UZ-16 except in the nonwelded portion of Prow Pass

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. Status of understanding of the saturated-zone ground-water flow system at Yucca Mountain, Nevada, as of 1995

    International Nuclear Information System (INIS)

    Yucca Mountain, which is being studied extensively because it is a potential site for a high-level radioactive-waste repository, consists of a thick sequence of volcanic rocks of Tertiary age that are underlain, at least to the southeast, by carbonate rocks of Paleozoic age. Stratigraphic units important to the hydrology of the area include the alluvium, pyroclastic rocks of Miocene age (the Timber Mountain Group; the Paintbrush Group; the Calico Hills Formation; the Crater Flat Group; the Lithic Ridge Tuff; and older tuffs, flows, and lavas beneath the Lithic Ridge Tuff), and sedimentary rocks of Paleozoic age. The saturated zone generally occurs in the Calico Hills Formation and stratigraphically lower units. The saturated zone is divided into three aquifers and two confining units. The flow system at Yucca Mountain is part of the Alkali Flat-Furnace Creek subbasin of the Death Valley groundwater basin. Variations in the gradients of the potentiometric surface provided the basis for subdividing the Yucca Mountain area into zones of: (1) large hydraulic gradient where potentiometric levels change at least 300 meters in a few kilometers; (2) moderate hydraulic gradient where potentiometric levels change about 45 meters in a few kilometers; and (3) small hydraulic gradient where potentiometric levels change only about 2 meters in several kilometers. Vertical hydraulic gradients were measured in only a few boreholes around Yucca Mountain; most boreholes had little change in potentiometric levels with depth. Limited hydraulic testing of boreholes in the Yucca Mountain area indicated that the range in transmissivity was more than 2 to 3 orders of magnitude in a particular hydrogeologic unit, and that the average values for the individual hydrogeologic units generally differed by about 1 order of magnitude. The upper volcanic aquifer seems to be the most permeable hydrogeologic unit, but this conclusion was based on exceedingly limited data

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  16. Chlorine-36 validation Study at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    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 (36Cl) 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 36Cl to total chloride (36Cl/CL) at the level of the proposed repository indicated that small amounts of water carrying bomb-pulse 36Cl (i.e., 36Cl/Cl ratios greater than 1250 x 10-15 resulting from 36Cl 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 36Cl/Cl data with an independent validation study. DOE asked the USGS to design and implement a validation study that

  17. Potential Future Igneous Activity at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    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 10-8 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 10-8 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 contents of the

  18. Pre-construction geologic section along the cross drift through the potential high-level radioactive waste repository, Yucca Mountain, Nye County, Nevada

    International Nuclear Information System (INIS)

    As part of the Site Characterization effort for the US Department of Energy's Yucca Mountain Project, tunnels excavated by tunnel boring machines provide access to the volume of rock that is under consideration for possible underground storage of high-level nuclear waste beneath Yucca Mountain, Nevada. The Exploratory Studies Facility, a 7.8-km-long, 7.6-m-diameter tunnel, has been excavated, and a 2.8-km-long, 5-m-diameter Cross Drift will be excavated in 1998 as part of the geologic, hydrologic and geotechnical evaluation of the potential repository. The southwest-trending Cross Drift branches off of the north ramp of the horseshoe-shaped Exploratory Studies Facility. This report summarizes an interpretive geologic section that was prepared for the Yucca Mountain Project as a tool for use in the design and construction of the Cross Drift

  19. Analysis of gaseous-phase stable and radioactive isotopes in the unsaturated zone, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    The Nevada Nuclear Waste Storage Investigations Project of the US Department of Energy provides that agency with data for evaluating volcanic tuff beneath Yucca Mountain, Nevada, to determine its suitability for a potential repository of high-level radioactive waste. Thickness of the unsaturated zone, which consists of fractured, welded and nonwelded tuff, is about 1640 to 2460 feet (500 to 750 meters). One question to be resolved is an estimate of minimum ground-water traveltime from the disturbed zone of the potentail repository to the accessible environment. Another issue is the potential for diffusive or convective gaseous transport of radionuclides from an underground facility in the unsaturated zone to the accessible environment. Gas samples were collected at intervals to a depth of 1200 feet from the unsaturated zone at Yucca Mountain, Nevada. Samples were analyzed for major atmospheric gases; carbon dioxide in the samples was analyzed for carbon-14 activity and for delta13C; water vapor in the samples was analyzed for deuterium and oxygen-18. These data could provide insight into the nature of unsaturated zone transport processes. 15 refs., 4 figs., 4 tabs

  20. Numerical studies of rock-gas flow in Yucca Mountain

    International Nuclear Information System (INIS)

    A computer model (TGIF -- Thermal Gradient Induced Flow) of two-dimensional, steady-state rock-gas flow driven by temperature and humidity differences is described. The model solves for the ''fresh-water head,'' a concept that has been used in models of variable-density water flow but has not previously been applied to gas flow. With this approach, the model can accurately simulate the flows driven by small differences in temperature. The unsaturated tuffs of Yucca Mountain, Nevada, are being studied as a potential site for a repository for high-level nuclear waste. Using the TGIF model, preliminary calculations of rock-gas flow in Yucca Mountain are made for four east-west cross-sections through the mountain. Calculations are made for three repository temperatures and for several assumptions about a possible semi-confining layer above the repository. The gas-flow simulations are then used to calculate travel-time distributions for air and for radioactive carbon-14 dioxide from the repository to the ground surface

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

    International Nuclear Information System (INIS)

    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

  2. Water levels in the Yucca Mountain Area, Nevada, 1996

    International Nuclear Information System (INIS)

    Water levels were monitored in 24 wells in the Yucca Mountain area, Nevada, during 1996. Twenty-two wells representing 28 depth intervals were monitored periodically, generally on a monthly basis, and 2 wells representing 3 depth intervals were monitored both hourly and periodically. All wells monitor water levels in Tertiary volcanic rocks except one that monitors water levels in paleozoic carbonate rocks. Water levels were measured using either calibrated steel tapes or a pressure sensor. Mean water-level altitudes in the Tertiary volcanic rocks ranged from about 727.86 to about 1,034.58 meters above sea level during 1996. The mean water-level altitude in the well monitoring the Paleozoic carbonate rocks was about 752.57 meters above sea level during 1996. Mean water-level altitudes for 1996 were an average of about 0.06 meter lower than 1995 mean water-level altitudes and 0.03 meter lower than 1985--95 mean water-level altitudes. During 1996, water levels in the Yucca Mountain area could have been affected by long-term pumping at the C-hole complex that began on May 8, 1996. Through December 31, 1996, approximately 196 million liters were pumped from well UE-25 c number-sign 3 at the C-hole complex. Other ground-water pumpage in the Yucca Mountain area includes annual pumpage from water-supply wells UE-25 J-12 and UE-25 J-13 of approximately 163 and 105 million liters, respectively, and pumpage from well USW G-2 for hydraulic testing during February and April 1996 of approximately 6 million liters

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

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, S.I.; Larson, L.T.; Noble, D.C. [Univ. of Nevada, Reno, NV (United States)

    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.

  4. Water levels in the Yucca Mountain Area, Nevada, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Graves, R.P.

    1998-11-01

    Water levels were monitored in 24 wells in the Yucca Mountain area, Nevada, during 1996. Twenty-two wells representing 28 depth intervals were monitored periodically, generally on a monthly basis, and 2 wells representing 3 depth intervals were monitored both hourly and periodically. All wells monitor water levels in Tertiary volcanic rocks except one that monitors water levels in paleozoic carbonate rocks. Water levels were measured using either calibrated steel tapes or a pressure sensor. Mean water-level altitudes in the Tertiary volcanic rocks ranged from about 727.86 to about 1,034.58 meters above sea level during 1996. The mean water-level altitude in the well monitoring the Paleozoic carbonate rocks was about 752.57 meters above sea level during 1996. Mean water-level altitudes for 1996 were an average of about 0.06 meter lower than 1995 mean water-level altitudes and 0.03 meter lower than 1985--95 mean water-level altitudes. During 1996, water levels in the Yucca Mountain area could have been affected by long-term pumping at the C-hole complex that began on May 8, 1996. Through December 31, 1996, approximately 196 million liters were pumped from well UE-25 c{number_sign}3 at the C-hole complex. Other ground-water pumpage in the Yucca Mountain area includes annual pumpage from water-supply wells UE-25 J-12 and UE-25 J-13 of approximately 163 and 105 million liters, respectively, and pumpage from well USW G-2 for hydraulic testing during February and April 1996 of approximately 6 million liters.

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

    Energy Technology Data Exchange (ETDEWEB)

    Flynn, T.; Buchanan, P.; Trexler, D. [Nevada Univ., Las Vegas, NV (United States). Harry Reid Center for Environmental Studies, Division of Earth Sciences; Shevenell, L., Garside, L. [Nevada Univ., Reno, NV (United States). Mackay School of Mines, Nevada Bureau of Mines and Geology

    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.

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

    International Nuclear Information System (INIS)

    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

  7. Design basis event consequence analyses for the Yucca Mountain project

    International Nuclear Information System (INIS)

    Design basis event (DBE) definition and analysis is an ongoing and integrated activity among the design and analysis groups of the Yucca Mountain Project (YMP). DBE's are those that potentially lead to breach of the waste package and waste form (e.g., spent fuel rods) with consequent release of radionuclides to the environment. A Preliminary Hazards Analysis (PHA) provided a systematic screening of external and internal events that were candidate DBE's that will be subjected to analyses for radiological consequences. As preparation, pilot consequence analyses for the repository subsurface and surface facilities have been performed to define the methodology, data requirements, and applicable regulatory limits

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

    International Nuclear Information System (INIS)

    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:

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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

  12. The Integration and Abstraction of EBS Models in Yucca Mountain Performance Assessment

    International Nuclear Information System (INIS)

    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 km2 emplacement area of the repository). A

  13. Late glacial to modern climate near Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Climate plays an important role in evaluating the suitability of Yucca Mountain, Nevada, as a potential high-level nuclear waste repository. Present-day global atmospheric circulation patterns are responsible for the semi-arid climate in the southwestern USA that result in limited winter precipitation and hot, relatively dry summers. Changes in global circulation may produce dramatic climate change resulting in colder average annual air temperatures and much higher average annual precipitation. Preliminary estimates from fossil plant and animal records suggest that during the last glacial (14 to 25 ka) mean annual precipitation may have been as much as five times modern, while mean annual temperatures were 8-10 degrees C lower than today. Such conditions may have been responsible for past percolation through the mountain recorded by the secondary carbonate and silica fracture mineralization within the unsaturated zone

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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

  17. Development of Earthquake Ground Motion Input for Preclosure Seismic Design and Postclosure Performance Assessment of a Geologic Repository at Yucca Mountain, NV

    Energy Technology Data Exchange (ETDEWEB)

    I. Wong

    2004-11-05

    This report describes a site-response model and its implementation for developing earthquake ground motion input for preclosure seismic design and postclosure assessment of the proposed geologic repository at Yucca Mountain, Nevada. The model implements a random-vibration theory (RVT), one-dimensional (1D) equivalent-linear approach to calculate site response effects on ground motions. The model provides results in terms of spectral acceleration including peak ground acceleration, peak ground velocity, and dynamically-induced strains as a function of depth. In addition to documenting and validating this model for use in the Yucca Mountain Project, this report also describes the development of model inputs, implementation of the model, its results, and the development of earthquake time history inputs based on the model results. The purpose of the site-response ground motion model is to incorporate the effects on earthquake ground motions of (1) the approximately 300 m of rock above the emplacement levels beneath Yucca Mountain and (2) soil and rock beneath the site of the Surface Facilities Area. A previously performed probabilistic seismic hazard analysis (PSHA) (CRWMS M&O 1998a [DIRS 103731]) estimated ground motions at a reference rock outcrop for the Yucca Mountain site (Point A), but those results do not include these site response effects. Thus, the additional step of applying the site-response ground motion model is required to develop ground motion inputs that are used for preclosure and postclosure purposes.

  18. Development of Earthquake Ground Motion Input for Preclosure Seismic Design and Postclosure Performance Assessment of a Geologic Repository at Yucca Mountain, NV

    International Nuclear Information System (INIS)

    This report describes a site-response model and its implementation for developing earthquake ground motion input for preclosure seismic design and postclosure assessment of the proposed geologic repository at Yucca Mountain, Nevada. The model implements a random-vibration theory (RVT), one-dimensional (1D) equivalent-linear approach to calculate site response effects on ground motions. The model provides results in terms of spectral acceleration including peak ground acceleration, peak ground velocity, and dynamically-induced strains as a function of depth. In addition to documenting and validating this model for use in the Yucca Mountain Project, this report also describes the development of model inputs, implementation of the model, its results, and the development of earthquake time history inputs based on the model results. The purpose of the site-response ground motion model is to incorporate the effects on earthquake ground motions of (1) the approximately 300 m of rock above the emplacement levels beneath Yucca Mountain and (2) soil and rock beneath the site of the Surface Facilities Area. A previously performed probabilistic seismic hazard analysis (PSHA) (CRWMS M and O 1998a [DIRS 103731]) estimated ground motions at a reference rock outcrop for the Yucca Mountain site (Point A), but those results do not include these site response effects. Thus, the additional step of applying the site-response ground motion model is required to develop ground motion inputs that are used for preclosure and postclosure purposes

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    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.

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

    International Nuclear Information System (INIS)

    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

  3. A demonstration of dose modeling at Yucca Mountain

    International Nuclear Information System (INIS)

    The U. S. Environmental Protection Agency is currently revising the regulatory guidance for high-level nuclear waste disposal. In its draft form, the guidelines contain dose limits. Since this is likely to be the case in the final regulations, it is essential that the US Department of Energy be prepared to calculate site-specific doses for any potential repository location. This year, Pacific Northwest Laboratory (PNL) has made a first attempt to estimate doses for the potential geologic repository at Yucca Mountain, Nevada as part of a preliminary total-systems performance assessment. A set of transport scenarios was defined to assess the cumulative release of radionuclides over 10,000 years under undisturbed and disturbed conditions at Yucca Mountain. Dose estimates were provided for several of the transport scenarios modeled. The exposure scenarios used to estimate dose in this total-systems exercise should not, however, be considered a definitive set of scenarios for determining the risk of the potential repository. Exposure scenarios were defined for waterborne and surface contamination that result from both undisturbed and disturbed performance of the potential repository. The exposure scenarios used for this analysis were designed for the Hanford Site in Washington. The undisturbed performance scenarios for which exposures were modeled are gas-phase release of 14C to the surface and natural breakdown of the waste containers with waterborne release. The disturbed performance scenario for which doses were estimated is exploratory drilling. Both surface and waterborne contamination were considered for the drilling intrusion scenario

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

    International Nuclear Information System (INIS)

    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 13C content of soil CO2, CaCO3, precipitation mechanisms, and isotopic fractionations between parent fluids and precipitating carbonates. The 13C content of soil carbon dioxide from Yucca Mountain and vicinity shows most of the usual patterns expected in such contexts: Decreasing 13C content with depth decreasing 13C with altitude and reduced 13C 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 CO2 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

  5. Inquiring minds want to know about Yucca Mountain

    International Nuclear Information System (INIS)

    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

  6. Autotrophic and heterotrophic bacterial diversity from Yucca Mountain

    International Nuclear Information System (INIS)

    A basic understanding of the types and functions of microbiota present within the deep subsurface of Yucca Mountain will be important in terms of modeling the long term stability of a nuclear waste repository. Microorganisms can degrade building materials used in tunnel construction such as concrete and steel. For example, high concentrations of nitrifying bacteria, may cause corrosion of concrete due to the release of nitric acid. Likewise, sulfur-oxidizing and iron-oxidizing bacteria have been implicated in microbially influenced corrosion (MIC), and may contribute to the degradation of waste packages. In addition, the metabolic activities of microbiota may alter the geochemistry of surrounding environments, which may in turn influence the permeability of subsurface strata and the fate of radioactive compounds. Microorganisms that play roles in these processes have diverse methods of obtaining the energy required for growth and metabolism and have been recovered from a wide range of environments, including the deep subsurface. The purpose of this research was to determine if these bacterial groups, important to the long-term success of a high-level nuclear waste repository, were indigenous to Yucca Mountain

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

    International Nuclear Information System (INIS)

    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 ampersand 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

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

    International Nuclear Information System (INIS)

    Magnetic anomalies over Yucca Mountain and surround 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-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. 14 references, 2 figures

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

    Energy Technology Data Exchange (ETDEWEB)

    Younker, J.L.; Andrews, W.B.; Fasano, G.A.; Herrington, C.C.; Mattson, S.R.; Murray, R.C. [Science Applications International Corp., Las Vegas, NV (United States); Ballou, L.B.; Revelli, M.A. [Lawrence Livermore National Lab., CA (United States); Ducharme, A.R.; Shephard, L.E. [Sandia National Labs., Albuquerque, NM (United States); Dudley, W.W.; Hoxie, D.T. [Geological Survey, Denver, CO (United States); Herbst, R.J.; Patera, E.A. [Los Alamos National Lab., NM (United States); Judd, B.R. [Decision Analysis Co., Portola Valley, CA (United States); Docka, J.A.; Rickertsen, L.D. [Weston Technical Associates, Washington, DC (United States)

    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.``

  10. Selected analyses to evaluate the effect of the exploratory shafts on repository performance at Yucca Mountain: Yucca Mountain Project

    International Nuclear Information System (INIS)

    This report presents a number of analyses to determine whether the construction of two shafts associated with the exploratory shaft facility can significantly influence the long-term isolation capabilities of a high-level nuclear waste repository at Yucca Mountain, on and adjacent to the Nevada Test Site. Both shafts are planned to be located predominantly in fractured, welded tuff within the unsaturated zone. The calculational effort, using analytical solutions, focuses primarily on the potential influence of the shaft liner and the zone of increased rock damage around the shaft (termed in this paper the modified permeability zone, MPZ). Two mechanisms are considered in determining whether the MPZ can significantly enhance radionuclide releases. These mechanisms include water flow entering the exploratory shafts from both realistic and improbable scenarios and airflow exiting the shaft as a result of convective and barometric forces. The influence of the liner on the performance of the repository is determined by evaluating the potential chemical interaction between ground water and the concrete liner and the subsequent potential for precipitates to deposit within the MPZ and the shaft fill. It is concluded from these calculations and the current knowledge of the hydrology of the unsaturated zone at Yucca Mountain that the presence of the shafts and the associated MPZ and shaft liner do not significantly impact the long-term isolation capability of the repository. 68 refs., 54 figs., 12 tabs

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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 System. 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

  14. Aeromagnetic surveys across Crater Flat and parts of Yucca Mountain, Nevada; TOPICAL

    International Nuclear Information System (INIS)

    As part of a study to characterize a potential nuclear waste repository at Yucca Mountain, aeromagnetic surveys were conducted in April 1993 along the trace of a planned seismic profile across Crater Flat and parts of Yucca Mountain. This report includes a presentation and preliminary interpretation of the data. The profiles are at scales of 1:100,000. Also included are a gridded color contour map of the newly acquired data and a discussion of the likely applicability of very-low-frequency (VLF) electromagnetic surveys to Yucca Mountain investigations

  15. Manganese-oxide minerals in fractures of the Crater Flat Tuff in drill core USW G-4, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    The Crater Flat Tuff is almost entirely below the water table in drill hole USW G-4 at Yucca Mountain, Nevada. Manganese-oxide minerals from the Crater Flat Tuff in USW G-4 were studied using optical, scanning electron microscopic, electron microprobe, and x-ray powder diffraction methods to determine their distribution, mineralogy, and chemistry. Manganese-oxide minerals coat fractures in all three members of the Crater Flat Tuff (Prow Pass, Bullfrog, and Tram), but they are most abundant in fractures in the densely welded devitrified intervals of these members. The coatings are mostly of the cryptomelane/hollandite mineral group, but the chemistry of these coatings varies considerably. Some of the chemical variations, particularly the presence of calcium, sodium, and strontium, can be explained by admixture with todorokite, seen in some x-ray powder diffraction patterns. Other chemical variations, particularly between Ba and Pb, demonstrate that considerable substitution of Pb for Ba occurs in hollandite. Manganese-oxide coatings are common in the 10-m interval that produced 75% of the water pumped from USW G-4 in a flow survey in 1983. Their presence in water-producing zones suggests that manganese oxides may exert a significant chemical effect on groundwater beneath Yucca Mountain. In particular, the ability of the manganese oxides found at Yucca Mountain to be easily reduced suggests that they may affect the redox conditions of the groundwater and may oxidize dissolved or suspended species. Although the Mn oxides at Yucca Mountain have low exchange capacities, these minerals may retard the migration of some radionuclides, particularly the actinides, through scavenging and coprecipitation. 23 refs., 21 figs., 2 tabs

  16. UPDATE TO THE PROBABILISTIC VOLCANIC HAZARD ANALYSIS, YUCCA MOUNTAIN, NEVADA

    International Nuclear Information System (INIS)

    A probabilistic volcanic hazard analysis (PVHA) was conducted in 1996 for the proposed repository at Yucca Mountain, Nevada. Based on data gathered by the Yucca Mountain Project over the course of about 15 years, the analysis integrated the judgments of a panel of ten volcanic experts using methods of formal expert elicitation. PVHA resulted in a probability distribution of the annual frequency of a dike intersecting the repository, which ranges from 10E-7 to 10E-10 (mean 1.6 x 10E-8). The analysis incorporates assessments of the future locations, rates, and types of volcanic dikes that could intersect the repository, which lies about 300 m below the surface. A particular focus of the analysis is the quantification of uncertainties. Since the 1996 PVHA, additional aeromagnetic data have been collected in the Yucca Mountain region, including a high-resolution low-altitude survey. A number of anomalies have been identified within alluvial areas and modeling suggests that some of these may represent buried eruptive centers (basaltic cinder cones). A program is currently underway to drill several of the anomalies to gain information on their origin and, if basalt, their age and composition. To update the PVHA in light of the new aeromagnetic and drilling data as well as other advancements in volcanic hazard modeling over the past decade, the expert panel has been reconvened and the expert elicitation process has been fully restarted. The analysis requires assessments of the spatial distribution of igneous events, temporal distributions, and geometries and characteristics of future events (both intrusive and extrusive). The assessments are for future time periods of 10,000 years and 1,000,000 years. Uncertainties are being quantified in both the conceptual models that define these elements as well as in the parameters for the models. The expert elicitation process is centered around a series of workshops that focus on the available data; alternative approaches to

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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 (14C-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

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

    International Nuclear Information System (INIS)

    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

  2. An evaluation of rail access routes to Yucca Mountain

    International Nuclear Information System (INIS)

    This paper provides a preliminary evaluation and characterization of potential rail routes for the transport of high level radioactive waste from their current storage locations (76 power plants and 4 federal facilities) to the proposed geologic repository at Yucca Mountain, Nevada. Individual routes were determined for shipments from each origin using the INTERLINE model. They were characterized in terms of shipment distance, number of transfers and states transversed. Additionally, specific routing constraints were imposed for a selected subset of the origins to address policy and operational alternatives such as minimizing shipment distance, number of transfers or number of states traversed. Results of the analysis indicate that the imposition of the routing constraint count result in reducing shipment distances, and the number of states traversed. But a tradeoff between these factors and the number of transfers exists

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. Software quality assurance on the Yucca Mountain Site Characterization Project

    International Nuclear Information System (INIS)

    The Yucca Mountain Site Characterization Project (YMP) has been involved over the years in the continuing struggle with establishing acceptable Software Quality Assurance (SQA) requirements for the development, modification, and acquisition of computer programs used to support the Mined Geologic Disposal System. These computer programs will be used to produce or manipulate data used directly in site characterization, design, analysis, performance assessment, and operation of repository structures, systems, and components. Scientists and engineers working on the project have claimed that the SQA requirements adopted by the project are too restrictive to allow them to perform their work. This paper will identify the source of the original SQA requirements adopted by the project. It will delineate the approach used by the project to identify concerns voiced by project engineers and scientists regarding the original SQA requirements. It will conclude with a discussion of methods used to address these problems in the rewrite of the original SQA requirements

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

    International Nuclear Information System (INIS)

    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

  6. Science and students: Yucca Mountain project's education outreach program

    International Nuclear Information System (INIS)

    The U.S. Department of Energy (DOE) is very concerned about the lack of understanding of basic science. Increasingly, critical decisions regarding the use of energy, technology, and the environment are being made. A well-educated and science-literate public is vital to the success of these decisions. Science education and school instruction are integral parts of the DOE's public outreach program on the Yucca Mountain Site Characterization Project (YMP). Project staff and scientists speak to elementary, junior high, high school, and university students, accepting all speaking invitations. The objectives of this outreach program include the following: (1) educating Nevada students about the concept of a high-level nuclear waste repository; (2) increasing awareness of energy and environmental issues; (3) helping students understand basic concepts of earth science and geology in relation to siting a potential repository; and (4) giving students information about careers in science and engineering

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

    International Nuclear Information System (INIS)

    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

  8. Focusing Yucca Mountain program priorities through performance assessment

    International Nuclear Information System (INIS)

    A probability-based methodology has been developed and applied to predict the release of radioisotopes to the environment from an underground nuclear waste repository, considering the features and the characteristics that are present at Yucca Mountain. Experts in specific scientific and engineering disciplines combined their talents to generate a model to determine these radioactive releases. The disciplines represented by these experts include climatology, soil physics, volcanology, seismology, rock mechanics, waste package design, engineered barrier system design, gaseous transport, thermal analysis, geochemistry, hydrology, and risk analysis. The model was developed using a logic-tree approach in which uncertainties were quantified by specifying discrete alternatives, which constitute the various branches of the logic tree. Significant revisions and modifications of the model have been performed recently and are the subject of this paper

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  13. Waste package performance assessment for the Yucca Mountain project

    International Nuclear Information System (INIS)

    The authors completed a first cycle of model development from a specification to a computer program, PANDORA-1, for long-term performance assessment of waste packages. The model for one waste package at a time incorporates processes specific to the unsaturated environment at the proposed Yucca Mountain, NV, site. PANDORA-1 models the most likely processes and several modes of waste alteration and release. The development identified information needs for future models; many processes, local details, and combinations will have to be examined. Integration of ensemble performance and quantification of uncertainties are modeling steps at higher aggregation. Methodologies for these steps include sampling, which is well studied; we have focused on several open questions. The authors can now calculate the amount of variance reduction available from Latin hypercube sampling; it is a limited reduction. A new method, uncertainty analysis test-bed program compares the new with old sampling methods

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

    International Nuclear Information System (INIS)

    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

  15. Evolution of the unsaturated zone testing at Yucca Mountain

    International Nuclear Information System (INIS)

    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. Yucca Mountain transportation routes: Preliminary characterization and risk analysis

    International Nuclear Information System (INIS)

    In this study, rail and highway routes which may be used for shipments of high-level nuclear waste to a proposed repository at Yucca Mountain, Nevada are characterized. This characterization facilitates three types of impact analysis: comparative study, limited worst-case assessment, and more sophisticated probabilistic risk assessment techniques. Data for relative and absolute impact measures are provided to support comparisons of routes based on selected characteristics. A worst-case scenario assessment is included to determine potentially critical and most likely places for accidents or incidents to occur. The assessment facilitated by the data in this study is limited because impact measures are restricted to the identification of potential areas or persons affected. No attempt is made to quantify the magnitude of these impacts. Most likely locations for accidents to occur are determined relative to other locations within the scope of this study. Independent factors and historical trends used to identify these likely locations are only proxies for accident probability

  17. Yucca Mountain Site Characterization Project Waste Package Plan

    International Nuclear Information System (INIS)

    The goal of the US Department of Energy's (DOE) Yucca Mountain Site Characterization Project (YMP) waste package program is to develop, confirm the effectiveness of, and document a design for a waste package and associated engineered barrier system (EBS) for spent nuclear fuel and solidified high-level nuclear waste (HLW) that meets the applicable regulatory requirements for a geologic repository. The Waste Package Plan describes the waste package program and establishes the technical approach against which overall progress can be measured. It provides guidance for execution and describes the essential elements of the program, including the objectives, technical plan, and management approach. The plan covers the time period up to the submission of a repository license application to the US Nuclear Regulatory Commission (NRC). 1 fig

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

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    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.

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. The reclamation program for the Yucca Mountain Project

    International Nuclear Information System (INIS)

    The US DOE is required by law and other regulatory requirements to reclaim disturbances created by site characterization activities at Yucca Mountain. Because of the difficulty of reclaiming arid areas and the lack of site specific information on successful reclamation techniques and procedures, the DOE has developed a comprehensive reclamation program. The program consists of three phase: Planning, operational and research. The planning phase is a continuing process that ensures that program policy, goals, tasks and responsibilities are clearly identified and linked. Three inter-related planning documents have been released by the DOE that establish the program objectives and outline the steps needed to successfully meet those objectives. The operational phase uses best available knowledge to develop and implement reclamation plans that are site-specific for each disturbance. Reclamation activities start prior to any surface disturbance with a survey of each disturbance by trained scientists. The scientists survey the area for the presence of protected species or critical wildlife habitat. They also gather vegetation, landscape, soils and other environmental data that is used to assess the impact of the proposed disturbance. Recommendations can be made to either avoid areas or mitigate impacts. The operational phase includes interim reclamation to protect valuable resources and control erosion prior to final reclamation. Monitoring of reclaimed sites is conducted to correct problem areas and insure that reclamation objectives are achieved. The third phase of the reclamation program is designed to provide site-specific information on effective reclamation techniques through research and field demonstrations. Information on potentially successful techniques will be used to update to improve the effectiveness of the reclamation activities at Yucca Mountain

  3. Constructing the Exploratory Studies Facility at Yucca Mountain

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    Secondary carbonates occurring within the soils, faults, and subsurface fractures of Yucca Mountain contain some of the best available records of paleoclimate and paleohydrology 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 13C content of soil CO2, CaCO3 precipitation mechanisms, and isotopic fractionations between parent fluids and precipitating carbonates. The 13C content of soil carbon dioxide from Yucca Mountain and vicinity shows most of the usual patterns expected in such contexts: decreasing 13C content with depth (due mainly to increased importance of respired CO2), decreasing 13C with altitude (partially due to relatively more C-3 vegetation), and reduced 13C during spring (due again to higher rates of respiration, and reduced gas permeability of wet soils). 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 CO2 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

  5. Fracture Variability and Hydrologic Implications at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    An understanding of the role of fractures at Yucca Mountain, Nevada, is needed to evaluate the suitability of the site to host a high-level nuclear waste repository. Current infiltration rates at Yucca Mountain require water to move through some fractures in the unsaturated welded units because the matrix porosity and permeability of these units are too small to accommodate the total flow. Though only about 20% of connected fractures are estimated to actively transmit water, flow and transport within fractures can greatly affect repository performance because fractures could be fast pathways for migration of radioactive particles. Under the current design, the potential repository would be located in a densely welded tuff sequence with highly variable fracture characteristics. This variability, resulting largely from the presence of lithophysal cavities, creates heterogeneous flow patterns through the unsaturated zone. Lithophysal cavities interrupt the continuity of fractures they intersect and may locally influence fracture propagation. In welded nonlithophysal zones, fractures tend to be longer and more widely spaced than in lithophysal zones, which generally display a greater number of closely spaced, short-length fractures. Seepage of water into potential waste-emplacement drifts will be affected by the fracture characteristics within the surrounding rock wall. Fractures with sufficient capillary suction, permeability, and lateral connectivity can enhance capillary barrier effects and lateral diversion around drift openings, thus reducing the potential for seepage. Lithophysal units, which have high secondary permeability owing to an abundance of well-connected small fractures capable of accommodating lateral flow, may be more favorable for repository performance (i. e., promote less seepage) than nonlithophysal units. Conceptual models for fracture flow based on mapped geometric and hydrologic fracture characteristics are presented, emphasizing the relevant

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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 ampersand G Energy Measurements, Inc. (EG ampersand 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

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

    International Nuclear Information System (INIS)

    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

  12. Data Qualification Report Flowing Interval Data for Use On the Yucca Mountain Project

    International Nuclear Information System (INIS)

    be appropriately used in a wide variety of applications, so long as consideration is given to accuracy, precision and representativeness of the data for an intended use in a technical product. This qualification report addresses the specific flowing interval data sets selected to support the flowing interval studies in the Analysis and Modeling Report (AMR) ''Probability Distribution of Flowing Interval Spacing'' (Kuzio 1999). This AMR presents an analysis of the spacing of flowing intervals in the saturated volcanic rocks beneath Yucca Mountain. Based on a preponderance of evidence, the flowing interval data used in the AMR are recommended to be qualified for inclusion in technical products in support of the Site Recommendation for generalized uses as described in this report

  13. Data Qulaification Report Flowong Interval Data for Use On the Yucca Mountain Project

    Energy Technology Data Exchange (ETDEWEB)

    C.R. Wilson; T.A. Grant

    2000-08-03

    generalized use and can be appropriately used in a wide variety of applications, so long as consideration is given to accuracy, precision and representativeness of the data for an intended use in a technical product. This qualification report addresses the specific flowing interval data sets selected to support the flowing interval studies in the Analysis and Modeling Report (AMR) ''Probability Distribution of Flowing Interval Spacing'' (Kuzio 1999). This AMR presents an analysis of the spacing of flowing intervals in the saturated volcanic rocks beneath Yucca Mountain. Based on a preponderance of evidence, the flowing interval data used in the AMR are recommended to be qualified for inclusion in technical products in support of the Site Recommendation for generalized uses as described in this report.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ma, C.W.; Sit, R.C.; Zavoshy, S.J.; Jardine, L.J. [Bechtel National, Inc., San Francisco, CA (United States); Laub, T.W. [Sandia National Labs., Albuquerque, NM (United States)

    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.

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Carr, M.D.; Yount, J.C. (eds.)

    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.

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

    International Nuclear Information System (INIS)

    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

  20. Application of natural analogues in the Yucca Mountain project - overview

    International Nuclear Information System (INIS)

    The Natural Analogue Synthesis Report (NASR) [1] provides a compilation of information from analogues that test, corroborate, and add confidence to process models and model predictions pertinent to total system performance assessment (TSPA). The report updated previous work [2] with new literature examples and results of quantitative studies conducted by the Yucca Mountain Project (YMP). The intent of the natural analogue studies was to collect corroborative evidence from analogues to demonstrate greater understanding of processes expected to occur during postclosure of a proposed Yucca Mountain repository. Natural analogues, as used here, refer to either natural or anthropogenic systems in which processes similar to those expected to occur in a nuclear waste repository are thought to have occurred over long time periods (decades to millenia) and large spatial scales (up to tens of kilometers). In the past, the YMP has used analogues for testing and building confidence in conceptual and numerical process models in a number of ways. Yucca Mountain mineral alteration phases provided a self-analogue for postclosure alteration [3]. Thermodynamic parameters for silica minerals of the Wairakai, New Zealand geothermal field were added to databases used in geochemical modeling [4]. Scoping calculations of radionuclide transport using the Yucca Mountain TSPA numerical model were conducted for the Peqa Blanca site [5]. Eruption parameters from the Cerro Negro volcano, Nicaragua, were used to verify codes that model ash plume dispersion [6]. Analogues have also been used in supplemental science and performance analyses to provide multiple lines of evidence in support of both analyses and model reports (AMRs) [7]; in screening arguments for inclusion or exclusion of features, events, and processes (FEP)s in TSPAs; in the quantification of uncertainties [7]; in expert elicitations of volcanic and seismic hazards [8, 9] and in peer reviews [10]. Natural analogues may be applied

  1. Microbially-influenced corrosion capability of Yucca Mountain bacterial isolates

    Energy Technology Data Exchange (ETDEWEB)

    Pitonzo, B.; Castro, P.; Amy, P. [Univ. of Nevada, Las Vegas, NV (United States)] [and others

    1996-12-01

    Microorganisms implicated in microbially-influenced corrosion have been isolated from the deep subsurface at Yucca Mt. Iron-oxidizing (FeOx), sulfate-reducing (SRB), and exopolymer (EPS)-producing bacteria were found. Microbial corrosion rate was monitored electrochemically. The test system was composed of a 1020 carbon steel coupon immersed in soft R2A agar prepared with simulated groundwater (J-13). A KCl bridge was used to connect the test and reference cell (calomel electrode). A platinum counter-electrode was used to apply a potential to the coupon and the corrosion process was measured by a potentiostat (Gamry). Corrosion cells (3x) were inoculated with purified cultures of EPS-producing bacteria and enrichment cultures of FeOx and SRB bacteria. Test cells were inoculated with microorganisms separately, as well as in various combinations. An uninoculated control cell was prepared to assess abiotic corrosion. Average corrosion rates were measured in milli-inches per year (mpy) against time. The control, and cells containing EPS-producing, FeOx or SRB bacteria alone or in combination demonstrated a rapid decrease in corrosion rate by 3 days. The corrosion rates stabilized, and at 35 days peaked at 2.25 mpy (FeOx), 3.30 mpy (SRB), and 2.80 mpy (EPS). AU of these values were significantly higher than the corrosion rate observed in the control cell, 1.30 mpy at 35 days. The various combinations demonstrated higher corrosion rates than any bacterial group alone. Coupons were cleaned, revealing surface pits. 200 pits/sq. in. were counted on a coupon previously exposed to a mixture of EPS-producing and FeOx microorganisms. Pit diameter ranged from 0.25 to 2.75 mm. The results indicate that Yucca Mountain microorganisms, alone and in combination, are capable of causing corrosion of 1020 carbon steel.

  2. Microbially-influenced corrosion capability of Yucca Mountain bacterial isolates

    International Nuclear Information System (INIS)

    Microorganisms implicated in microbially-influenced corrosion have been isolated from the deep subsurface at Yucca Mt. Iron-oxidizing (FeOx), sulfate-reducing (SRB), and exopolymer (EPS)-producing bacteria were found. Microbial corrosion rate was monitored electrochemically. The test system was composed of a 1020 carbon steel coupon immersed in soft R2A agar prepared with simulated groundwater (J-13). A KCl bridge was used to connect the test and reference cell (calomel electrode). A platinum counter-electrode was used to apply a potential to the coupon and the corrosion process was measured by a potentiostat (Gamry). Corrosion cells (3x) were inoculated with purified cultures of EPS-producing bacteria and enrichment cultures of FeOx and SRB bacteria. Test cells were inoculated with microorganisms separately, as well as in various combinations. An uninoculated control cell was prepared to assess abiotic corrosion. Average corrosion rates were measured in milli-inches per year (mpy) against time. The control, and cells containing EPS-producing, FeOx or SRB bacteria alone or in combination demonstrated a rapid decrease in corrosion rate by 3 days. The corrosion rates stabilized, and at 35 days peaked at 2.25 mpy (FeOx), 3.30 mpy (SRB), and 2.80 mpy (EPS). AU of these values were significantly higher than the corrosion rate observed in the control cell, 1.30 mpy at 35 days. The various combinations demonstrated higher corrosion rates than any bacterial group alone. Coupons were cleaned, revealing surface pits. 200 pits/sq. in. were counted on a coupon previously exposed to a mixture of EPS-producing and FeOx microorganisms. Pit diameter ranged from 0.25 to 2.75 mm. The results indicate that Yucca Mountain microorganisms, alone and in combination, are capable of causing corrosion of 1020 carbon steel

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    International Nuclear Information System (INIS)

    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 and 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 and O 2000g) based on the repository footprint known as the Enhanced Design Alternative [EDA II, Design B (CRWMS M and O 1999a; Wilkins and Heath 1999)]. Then, the ''Site Recommendation Design Baseline'' (CRWMS M and O 2000a) initiated a change in the repository design, which is described in the ''Site Recommendation Subsurface Layout'' (CRWMS M and 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 and O 2000b). The calculations for both footprints are presented in this AMR. In

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

    International Nuclear Information System (INIS)

    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

  8. Water levels in the Yucca Mountain area, Nevada, 1994

    International Nuclear Information System (INIS)

    Water levels were monitored in 28 wells in the Yucca Mountain area, Nevada, during 1994. Twelve wells representing 13 intervals were monitored periodically, generally on a monthly basis, 6 wells representing 10 intervals were monitored hourly, and 10 wells representing 13 intervals were monitored both periodically and 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, a multiconductor cable unit, and pressure transducers. Water-level altitudes in the Tertiary volcanic rocks ranged from about 728 to about 1,034 meters above sea level during 1994. The mean-annual water-level altitude in the well monitoring the Paleozoic carbonate rocks was about 753 meters above sea level during 1994. Water levels were only an average of about 0.01 meters lower than 1993 water levels. All data were acquired in accordance with a quality-assurance program to support the reliability of the data

  9. Volcanic hazard studies for the Yucca Mountain project

    International Nuclear Information System (INIS)

    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

  10. Corrosion of candidate container materials by Yucca Mountain bacteria

    International Nuclear Information System (INIS)

    Several candidate container materials have been studied in modified Yucca Mountain (YM) ground water in the presence or absence of YM bacteria. YM bacteria increased corrosion rates by 5--6 fold in UNS G10200 carbon steel, and nearly 100-fold in UNS N04400 Ni-Cu alloy. YM bacteria caused microbiologically influenced corrosion (MIC) through de-alloying or Ni-depletion of Ni-Cu alloy as evidenced by scanning electronic microscopy (SEM) and inductively coupled plasma spectroscopy (ICP) analysis. MIC rates of more corrosion-resistant alloys such as UNS N06022 Ni-Cr-Mo- W alloy, UNS N06625 Ni-Cr-Mo alloy, and UNS S30430 stainless steel were measured below 0.05 microm/yr, however YM bacteria affected depletion of Cr and Fe relative to Ni in these materials. The chemical change on the metal surface caused by depletion was characterized in anodic polarization behavior. The anodic polarization behavior of depleted Ni-based alloys was similar to that of pure Ni

  11. Distributional equity problems at the proposed Yucca Mountain facility

    International Nuclear Information System (INIS)

    This paper addresses one quite specific part of this broad range of issues -- the distribution of impacts to the state of Nevada and to the nation likely to be associated with the proposed Yucca Mountain repository. As such, it is one of four needed analyses of the overall equity problems and needs to be read in conjunction with our proposed overall framework for equity studies. The objective of this report is to consider how an analysis might be made of the distribution of projected outcomes between the state and nation. At the same time, it needs to be clear that no attempt will be made actually to implement the analysis that is proposed. What follows is a conceptual statement that identifies the analytical issues and pro poses an approach for overcoming them. Significantly, it must also be noted that this report will not address procedural equity issues between the state and nation for this is the subject of a separate analysis. 14 refs., 8 figs., 3 tabs

  12. Volcanic hazard studies for the Yucca Mountain project

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. Yucca Mountain Site Characterization Project Technical Data Catalog

    International Nuclear Information System (INIS)

    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 (this edition), should be retained as the baseline document for the supplements until the end-of-year revision is published and distributed in October 1994

  14. Yucca Mountain Site Characterization Project Technical Data Catalog

    International Nuclear Information System (INIS)

    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. Each new publication of the Technical Data Catalog supersedes the previous edition

  15. Analysis of Yucca Mountain Pore-Water Chloride Data

    International Nuclear Information System (INIS)

    Distribution of chemical constituents in the unsaturated zone (UZ) system of Yucca Mountain, Nevada, depends on many factors, such as hydrological and geochemical processes of surface precipitation, evapotranspiration, the water-fracture-matrix interactions, large-scale mixing via lateral flow and transport, and the history of climate changes. This study analyzes pore-water chloride-concentration data and models the transport processes. The model results are then used to calibrate the UZ flow model with the aim of refining the infiltration distribution and percolation fluxes to the potential repository. The major chemical data used in this study were pore-water chloride (Cl) concentrations. The sensitivity of this conservative tracer to the UZ flow system is well known. This constituent was directly incorporated into a three-dimensional dual-permeability flow model. Chemical transport properties were taken into account. The surface flux of chloride was determined by the total amount of precipitation reaching the surface and chemical concentration in the precipitation. The entire flow system was divided into domains based on the distribution of pore-water chemical data, infiltration data, hydrogeological and hydrostructural features. Model calibration proceeded by adjusting the site-scale infiltration map and anisotropy permeabilities to reach a satisfying agreement between the simulated subsurface chloride distribution and measured data

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  18. Waste package performance assessment for the Yucca Mountain Project

    International Nuclear Information System (INIS)

    We completed a first cycle of model development from a specification to a computer program, PANDORA-1, for long-term performance assessment of waste packages. The model for one waste package at a time incorporates processes specific to the unsaturated environment at the proposed Yucca Mountain, NV, site. PANDORA-1 models the most likely processes and several modes of waste alteration and release. The development identified information needs for future models; many processes, local details, and combinations will have to be examined. Integration of ensemble performance and quantification of uncertainties are modeling steps at higher aggregation. Methodologies for these steps include sampling, which is well studied; we have focused on several open questions. We can now calculate the amount of variance reduction available from Latin hypercube sampling; it is a limited reduction. A new method, controlled sampling, provides substantial variance reduction for a broad range of model functions. An uncertainty analysis test-bed program compares the new with old sampling methods. 7 refs., 1 tab

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  20. Water levels in the Yucca Mountain area, Nevada, 1995

    International Nuclear Information System (INIS)

    Water levels were monitored in 28 wells in the Yucca Mountain area, Nevada, during 1995. Seventeen wells representing 18 depth intervals were monitored periodically, generally on a monthly basis, 2 wells representing 3 depth intervals were monitored hourly, and 9 wells representing 15 depth intervals were monitored both periodically and 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, a multiconductor cable unit, and/or pressure transducers. Mean water-level altitudes in the Tertiary volcanic rocks ranged from about 728 to about 1,034 meters above sea level during 1995. The mean water-level altitude in the well monitoring the Paleozoic carbonate rocks was about 753 meters above sea level during 1995. Mean water level altitudes were only an average of about 0.01 meters higher than 1994 mean water level altitudes. A single-well aquifer test was conducted on well UE-25 WT number-sign 12 during August and September 1995. Well USW 0-2 was also pumped during October and November 1995, in preparation for single-well aquifer test at that well. All data were acquired in accordance with a quality-assurance program to support the reliability of the data

  1. Corrosion of candidate container materials by Yucca Mountain bacteria

    International Nuclear Information System (INIS)

    Several candidate container materials have been studied in modified Yucca Mountain (YM) ground water in the presence or absence of YM bacteria. YM bacteria increased corrosion rates by 5-6 fold in UNS G10200 carbon steel, and nearly 100-fold in UNS NO4400 Ni-Cu alloy. YM bacteria caused microbiologically influenced corrosion (MIC) through de-alloying or Ni-depletion of Ni-Cu alloy as evidenced by scanning electronic microscopy (SEM) and inductively coupled plasma spectroscopy (ICP) analysis. MIC rates of more corrosion-resistant alloys such as UNS NO6022 Ni-Cr- MO-W alloy, UN's NO6625 Ni-Cr-Mo alloy, and UNS S30400 stainless steel were measured below 0.05 umyr, however YM bacteria affected depletion of Cr and Fe relative to Ni in these materials. The chemical change on the metal surface caused by depletion was characterized in anodic polarization behavior. The anodic polarization behavior of depleted Ni-based alloys was similar to that of pure Ni. Key words: MIC, container materials, YM bacteria, de-alloying, Ni-depletion, Cr-depletion, polarization resistance, anodic polarization,

  2. Repository site data report for Tuff: Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    As part of the US Nuclear Regulatory Commission (NRC) risk assessment methodology development programs for high-level nuclear waste disposal, repository site data reports are being prepared on each of the potential geologic media considered by the US Department of Energy (DOE). This report on Yucca Mountain at the Nevada Test Site (NTS) represents one part of this program and is based primarily on published site data. Where necessary, additional data from other parts of NTS or other tuff areas were used. The site consists of a thick sequence of tuff that overlies a Paleozoic, primarily carbonate, basement complex. North- to northeast-trending normal faults are the dominant structural features near the site. Within the tuff sequence, ground-water flow integrates systems from several drainage basins, while in the carbonate rocks, flow is regional in nature. At this time, only speculation about flow patterns is possible due to insufficient data. The tuff units usually contain sodium-potassium-bicarbonate water (pH range: 6.9 to 7.4). Redox potential is unknown at present. The high retardation potential of the tuffs is controlled primarily by the presence of zeolites and smectites. Because of the many rock types encompassed by the term tuff, values of thermomechanical properties also have a wide range

  3. Temperature Effects on seepage Fluid Compositions at Yucca Mountain

    International Nuclear Information System (INIS)

    This project investigated the effect of two repository operating temperature modes on coupled thermal, hydrological, and chemical processes around potential nuclear waste-emplacement tunnels (drifts) at Yucca Mountain, Nevada. The main objective of this study was to evaluate the composition of fluids (water and gas) that could enter the drifts, because these data directly relate to the performance of waste canisters and other in-drift engineered systems over the life of the potential repository. Multicomponent reactive transport simulations were performed using TOUGHREACT, initially written by T. Xu and K. Pruess at LBNL and modified here to handle high-temperature and boiling environments. Two repository operating temperature modes were investigated: (1) a ''high-temperature'' mode, which considered a short preclosure ventilation period (50 years) and gave rise to above-boiling temperatures in rocks around the drift for hundreds of years, and (2) a ''low-temperature'' mode with a smaller heat load and longer preclosure ventilation (300 years), yielding temperatures at the surface of the waste package below 85 C (a design threshold) and thus below boiling conditions. Simulations under ambient conditions (no heat load) were also conducted to serve as a baseline for comparing results of thermal-loading simulations

  4. Illstrative probabilistic biosphere model for Yucca Mountain individual risk calculations

    International Nuclear Information System (INIS)

    The proposed EPA Standards for the disposal of spent fuel, high-level and transuranic radioactive waste prescribe future biosphere--one in which no sustained human activity occurs inside the controlled zone, yet sustained use of groundwater occurs just outside the controlled zone boundary. Performance assessments have generally assumed a person at this location extracts all his water needs directly from the projected contaminated plume for all of his life. Dose to this maximally-exposed individual is too conservative a measure of performance for a nuclear waste repository and does not reflect the isolation characteristics of a site. A better measure is individual risk in which uncertainties in biosphere characteristics for the longer periods of performance, for a site like Yucca Mountain only those characteristics associated with well water scenarios need be prescribed. Such a prescription of the biosphere is appropriate because the goal of the regulations is to provide indicators of future performance so the regulators can make a responsible decision regarding reasonable assurance of public health and safety

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

    International Nuclear Information System (INIS)

    This document summarizes the strategy given in the Site Characterization Plan (1) for demonstrating compliance with the post closure performance objectives for the waste package and the Engineered Barrier System (EBS) contained in the Code of Federal Regulations. The strategy consists of the development of a conservative waste package design that will meet the regulatory requirements with sufficient margin for uncertainty using a multi-barrier approach that takes advantage of the unsaturated nature of the Yucca Mountain site. This strategy involves an iterative process designed to achieve compliance with the requirements for substantially complete containment and EBS release. The strategy will be implemented in such a manner that sufficient evidence will be provided for presentation to the Nuclear Regulatory Commission (NRC) so that it may make a finding that there is ''reasonable assurance'' that these performance requirements will indeed be met. In implementing the strategy, DOE recognizes four fundamental goals: (1) protect public health and safety; (2) minimize financial and other resource commitments; (3) comply with applicable laws and regulations; and (4) maintain an aggressive schedule. The strategy is intended to be a reasonable balance of these competing goals. 7 refs., 3 figs., 1 tab

  6. Volcanic hazard studies for the Yucca Mountain project

    International Nuclear Information System (INIS)

    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 105 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 103 to 105 yrs. Magma eruption rates are low and the time between eruptions exceeds the cooling time of the magma volumes. 25 refs., 2 figs

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

  12. Water levels in the Yucca Mountain area, Nevada, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Graves, R.P.; Tucci, P.; Goemaat, R.L.

    1996-12-31

    Water levels were monitored in 28 wells in the Yucca Mountain area, Nevada, during 1994. Twelve wells representing 13 intervals were monitored periodically, generally on a monthly basis, 6 wells representing 10 intervals were monitored hourly, and 10 wells representing 13 intervals were monitored both periodically and 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, a multiconductor cable unit, and pressure transducers. Water-level altitudes in the Tertiary volcanic rocks ranged from about 728 to about 1,034 meters above sea level during 1994. The mean-annual water-level altitude in the well monitoring the Paleozoic carbonate rocks was about 753 meters above sea level during 1994. Water levels were only an average of about 0.01 meters lower than 1993 water levels. All data were acquired in accordance with a quality-assurance program to support the reliability of the data.

  13. Water levels in the Yucca Mountain area, Nevada, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Graves, R.P.; Goemaat, R.L.

    1998-09-01

    Water levels were monitored in 28 wells in the Yucca Mountain area, Nevada, during 1995. Seventeen wells representing 18 depth intervals were monitored periodically, generally on a monthly basis, 2 wells representing 3 depth intervals were monitored hourly, and 9 wells representing 15 depth intervals were monitored both periodically and 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, a multiconductor cable unit, and/or pressure transducers. Mean water-level altitudes in the Tertiary volcanic rocks ranged from about 728 to about 1,034 meters above sea level during 1995. The mean water-level altitude in the well monitoring the Paleozoic carbonate rocks was about 753 meters above sea level during 1995. Mean water level altitudes were only an average of about 0.01 meters higher than 1994 mean water level altitudes. A single-well aquifer test was conducted on well UE-25 WT{number_sign}12 during August and September 1995. Well USW 0-2 was also pumped during October and November 1995, in preparation for single-well aquifer test at that well. All data were acquired in accordance with a quality-assurance program to support the reliability of the data.

  14. Anisotropy of mechanical properties of tuff at Yucca Mountain

    International Nuclear Information System (INIS)

    The purpose of this study is to investigate anisotropy of mechanical properties, namely, compressive strength and modulus, for Tiva Canyon welded tuff from the starter tunnel at Yucca Mountain. Mechanical properties of Tiva Canyon Tuff are needed for the design of the ramps and drifts within the Tiva Canyon horizon. Approximately one cubic foot block samples, all of which were from the thermo -- mechanical unit TCw, were obtained from a muck pile containing excavated rock from the starter tunnel. Specimens were cored from the block samples in two distinct orientations: parallel and perpendicular to the lithophysal cavity orientation. Since lithophysal cavity orientation is predominantly horizontal in the field, parallel specimens can be considered horizontal and perpendicular specimens vertical with respect to the rock mass. The specimens were NX sized (5.4 cm diameter) and had a length-to-diameter ratio of 2:1. The air dried specimens were tested at room temperature in a triaxial chamber at confining pressures of 0.1, 5, and 10 MPa, and at a compressive axial strain rate of 10-5 s-. The Young's Modulus values were calculated by a least squares fit of stress - strain data between 10 and 50% of the ultimate strength

  15. A Mountain-Scale Monitoring Network for Yucca Mountain Performance Confirmation

    International Nuclear Information System (INIS)

    Confirmation of the performance of Yucca Mountain is required by 10 CFR Part 63.131 to indicate, where practicable, that the natural system acts as a barrier, as intended. Hence, performance confirmation monitoring and testing would provide data for continued assessment during the pre-closure period. In general, to carry out testing at a relevant scale is always important, and in the case of performance confirmation, it is particularly important to be able to test at the scale of the repository. We view the large perturbation caused by construction of the repository at Yucca Mountain as a unique opportunity to study the large-scale behavior of the natural barrier system. Repository construction would necessarily introduce traced fluids and result in the creation of leachates. A program to monitor traced fluids and construction leachates permits evaluation of transport through the unsaturated zone and potentially downgradient through the saturated zone. A robust sampling and monitoring network for continuous measurement of important parameters, and for periodic collection of agrochemical samples, is proposed to observe thermo-hydrogeochemical changes near the repository horizon and down to the water table. The sampling and monitoring network can be used to provide data to (1) assess subsurface conditions encountered and changes in those conditions during construction and waste emplacement operations; and (2) for modeling to determine that the natural system is functioning as intended

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

    International Nuclear Information System (INIS)

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, H.W.; Ponce, D.A. [eds.] [Geological Survey, Menlo Park, CA (United States); Hunter, W.C. [ed.] [Geological Survey, Denver, CO (United States). Yucca Mountain Project Branch

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Shrader-Frechette, K. [University of South Florida, Tampa, FL (United States)

    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.

  20. Sequential evaluation of the potential geologic repository site at Yucca Mountain, Nevada, USA

    International Nuclear Information System (INIS)

    This paper discusses the changes that are planned for the characterization program at Yucca Mountain due to budget changes. Yucca Mountain is the only site being studied in the US for a geologic repository. Funding for the site characterization program at Yucca Mountain program was cut by roughly one half from the 1994 projected budget to complete three major milestones. These project milestones included: (1) a time-phased determination of site suitability, and if a positive finding, (2) completion of an Environmental Impact Statement, and (3) preparation of a License Application to the US NRC to authorize repository construction. In reaction, Yucca Mountain Site Characterization Project has shifted from parallel development of these milestones to a sequenced approach with the site suitability evaluation being replaced with a management assessment. Changes to the regulatory structure for the disposal program are under consideration by DOE and the NRC. The possibility for NRC and Doe to develop a site-specific regulatory structure follows from the National Energy Policy Act of 1992 that authorized the US EPA to develop a site specific environmental standard for Yucca Mountain

  1. Major results of gravity and magnetic studies at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, H.W.; Ponce, D.A.; Sikora, R.F.

    1991-05-01

    About 4000 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 {minus}10 mGal along the east edge of Yucca Mountain decrease to about {minus}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 1220 {plus_minus} 150 m, an estimate that was subsequently confirmed by drilling to be 1244 m. Three-dimensional modeling of the gravity low over Crater Flat indicates the thickness of Cenozoic volcanic rocks and alluvial cover to be about 3000 m. Considerable aeromagnetic coverage of southwestern Nevada was obtained in 1978--1979 to help characterize Yucca Mountain and vicinity. One significant result is the discovery of a series of circular magnetic anomalies in Crater Flat and the northern Amargosa Desert that suggest the presence of buried volcanic centers there. Elongate magnetic highs and associated lows over Yucca Mountain correlate with mapped faults, some of which are only partially exposed. Thus, the data provide inforamtion on the extent and continuity of these faults. 31 refs., 3 figs.

  2. Expert judgment in assessing radwaste risks: What Nevadans should know about Yucca Mountain

    International Nuclear Information System (INIS)

    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

  3. Environmental program overview for a high-level radioactive waste repository at Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1988-12-01

    The United States plans to begin operating the first repository for the permanent disposal of high-level nuclear waste early in the next century. In February 1983, the US Department of Energy (DOE) identified Yucca Mountain, in Nevada, as one of nine potentially acceptable sites for a repository. To determine its suitability, the DOE evaluated the Yucca Mountain site, along with eight other potentially acceptable sites, in accordance with the DOE`s General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. The purpose of the Environmental Program Overview (EPO) for the Yucca Mountain site is to provide an overview of the overall, comprehensive approach being used to satisfy the environmental requirements applicable to sitting a repository at Yucca Mountain. The EPO states how the DOE will address the following environmental areas: aesthetics, air quality, cultural resources (archaeological and Native American components), noise, radiological studies, soils, terrestrial ecosystems, and water resources. This EPO describes the environmental program being developed for the sitting of a repository at Yucca Mountain. 1 fig., 3 tabs.

  4. Environmental program overview for a high-level radioactive waste repository at Yucca Mountain

    International Nuclear Information System (INIS)

    The United States plans to begin operating the first repository for the permanent disposal of high-level nuclear waste early in the next century. In February 1983, the US Department of Energy (DOE) identified Yucca Mountain, in Nevada, as one of nine potentially acceptable sites for a repository. To determine its suitability, the DOE evaluated the Yucca Mountain site, along with eight other potentially acceptable sites, in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. The purpose of the Environmental Program Overview (EPO) for the Yucca Mountain site is to provide an overview of the overall, comprehensive approach being used to satisfy the environmental requirements applicable to sitting a repository at Yucca Mountain. The EPO states how the DOE will address the following environmental areas: aesthetics, air quality, cultural resources (archaeological and Native American components), noise, radiological studies, soils, terrestrial ecosystems, and water resources. This EPO describes the environmental program being developed for the sitting of a repository at Yucca Mountain. 1 fig., 3 tabs

  5. Mineralogic variation in drill core UE-25 UZ number-sign 16, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    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

  6. Major results of gravity and magnetic studies at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    About 4000 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 1220 ± 150 m, an estimate that was subsequently confirmed by drilling to be 1244 m. Three-dimensional modeling of the gravity low over Crater Flat indicates the thickness of Cenozoic volcanic rocks and alluvial cover to be about 3000 m. Considerable aeromagnetic coverage of southwestern Nevada was obtained in 1978--1979 to help characterize Yucca Mountain and vicinity. One significant result is the discovery of a series of circular magnetic anomalies in Crater Flat and the northern Amargosa Desert that suggest the presence of buried volcanic centers there. Elongate magnetic highs and associated lows over Yucca Mountain correlate with mapped faults, some of which are only partially exposed. Thus, the data provide inforamtion on the extent and continuity of these faults. 31 refs., 3 figs

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. Yucca Mountain program summary of research, site monitoring and technical review activities (January 1987--June 1988)

    International Nuclear Information System (INIS)

    Although studies of orbital mechanics provide speculative notions of future climatic trends, they cannot predict how these trends will manifest themselves in the immediate area around Yucca Mountain. The generally accepted approach to this question is to consider the climatic variations that have occurred during the last 10,000 years, and use these as a guide to the likely range of future variation in climate. However, because climatic studies around the world indicate that we are potentially on the verge of another ice age, we should also consider the conditions that predominated during the Pleistocene. The specific aim of this project is to derive the climatic history of Yucca Mountain during the last 20,000 years from the vegetation history. By integrating data obtained from pollen records, woodrat dens (middens), and tree-ring sequences from the Nevada Test Site (NTS) area, a regional climatic record is being generated that can be correlated to data obtained at Yucca Mountain to formulate a local climatic sequence there. This will then be used to determine the magnitude and frequency of climatic variation that have occurred during that time at Yucca Mountain. These data can then be used by other researchers to provide estimates of rainfall, recharge and soil chemical changes for modeling the past hydrology of Yucca Mountain

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

    Energy Technology Data Exchange (ETDEWEB)

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

    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.

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Barnard, R.W.; Wilson, M.L.; Dockery, H.A.; Kaplan, P.G.; Eaton, R.R.; Bingham, F.W. [Sandia National Labs., Albuquerque, NM (United States); Gauthier, J.H.; Robey, T.H. [Spectra Research Inst., Albuquerque, NM (United States)

    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.

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

    International Nuclear Information System (INIS)

    Partitioning the actinides in spent fuel and transmuting them in actinide-burning liquid-metal reactors (ALMRs) is a potential method of reducing public risks from the geologic disposal of nuclear waste. In this paper, the authors present a comparison of radionuclide releases from burial at Yucca Mountain of spent fuel and of ALMR wastes. Two waste disposal schemes are considered. In each, the heat generation of the wastes at emplacement is 9.88 x 107 W, the maximum for the repository. In the first scheme, the repository contains 86,700 tonnes of initial heavy metal (IHM) of light water reactor (LWR) spent fuel. In the second scheme, all current LWRs operate for a 40-yr lifetime, producing a total of 84,000 tonnes IHM of spent fuel. This spent fuel is treated using a pyrochemical process in which 98.4% of the uranium and 99.8% of the neptunium, plutonium, americium, and curium are extracted and fabricated into ALMR fuel, with the reprocessing wastes destined for the repository. The ALMR requires this fuel for its startup and first two reloads; thereafter, it is self-sufficient. Spent ALMR fuel is also pyrochemically reprocessed: 99.9% of the transuranics is recovered and recycled into ALMR fuel, and the wastes are placed in the repository. Thus, in the second scheme, the repository contains the wastes from reprocessing all of the LWR spent fuel plus the maximum amount of ALMR reprocessing wastes allowed in the repository based on its heat generation limit

  14. Construction features of the exploratory shaft at Yucca Mountain

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. Reactive Transport Modeling of the Yucca Mountain Site, Nevada

    International Nuclear Information System (INIS)

    The Yucca Mountain site has a dry climate and deep water table, with the repository located in the middle of an unsaturated zone approximately 600 m thick. Radionuclide transport processes from the repository to the water table are sensitive to the unsaturated zone flow field, as well as to sorption, matrix diffusion, radioactive decay, and colloid transport mechanisms. The unsaturated zone flow and transport models are calibrated against both physical and chemical data, including pneumatic pressure, liquid saturation, water potential, temperature, chloride, and calcite. The transport model predictions are further compared with testing specific to unsaturated zone transport: at Alcove 1 in the Exploratory Studies Facility (ESF), at Alcove 8 and Niche 3 of the ESF, and at the Busted Butte site. The models are applied to predict the breakthroughs at the water table for nonsorbing and sorbing radionuclides, with faults shown as the important paths for radionuclide transport. Daughter products of some important radionuclides, such as 239Pu and 241Am, have faster transport than the parents and must be considered in the unsaturated zone transport model. Colloid transport is significantly affected by colloid size, but only negligibly affected by lunetic declogging (reverse filtering) mechanisms. Unsaturated zone model uncertainties are discussed, including the sensitivity of breakthrough to the active fracture model parameter, as an example of uncertainties related to detailed flow characteristics and fracture-matrix interaction. It is expected that additional benefits from the unsaturated zone barrier for transport can be achieved by full implementation of the shadow zone concept immediately below the radionuclide release points in the waste emplacement drifts

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

    International Nuclear Information System (INIS)

    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 and 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

  19. Ventilation design for Yucca Mountain Exploratory Studies Facility

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

  1. Construction features of the Exploratory Shaft at Yucca Mountain

    International Nuclear Information System (INIS)

    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 1,480-foot-deep circular shaft lined with concrete to a finished inside diameter of 12 feet, lateral excavations and test installations extending up to 200 feet from the shaft, and long lateral borings extending up to 2,300 feet from the shaft. The estimated time for sinking the shaft to a total depth of about 1,480 feet 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 1,200 feet consists of the equivalent of 1,150 feet of 15- by 15-foot 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. Such techniques generally classified as ''smooth blasting'' are commonly used for excavation in the construction industry

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, T.C.; Geslin, J.K. [Science Applications International Corp., Golden, CO (United States); Flint, L.E. [U.S. Geological Survey, Yucca Mountain Project, Mercury, NV (United States)

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Stephan, P.M. [ed.

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

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

    International Nuclear Information System (INIS)

    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

  12. Geophysical investigations of buried volcanic centers near Yucca Mountain, Southwest Nevada

    International Nuclear Information System (INIS)

    Several aeromagnetic dipolar anomalies occur over flat, alluvial areas near Yucca Mountain that resemble anomalies typically associated with subaerial basaltic volcanic centers. Detailed gravity and ground magnetic data were collected along a surveyed traverse across an aeromagnetic anomaly in Amargosa Valley, south of Yucca Mountain, Nevada. Modeling of the ground magnetic data collected over the largest of these anomalies, the Lathrop Wells aeromagnetic anomaly, indicates that the top of the causative body, most likely basalt, is less than 250 m below the surface. Gravity data indicate an apparent lack of an associated gravity anomaly and suggest that either the causative body may be tuff rather than basalt, or the volume of the body is small. Both drilling and collection of more magnetic and gravity data are necessary because ages and volumes of buried volcanic centers are important constraints for estimating the probability of potential volcanism near the proposed nuclear waste repository at Yucca Mountain

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

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, H.W. [Geological Survey, Menlo Park, CA (USA); Hardin, E.L. [Science Applications International Corp., Las Vegas, NV (USA); Nelson, P.H. [Geological Survey, Denver, CO (USA)] [eds.

    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.

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

  17. Yucca Mountain Site Characterization Project bibliography, July--December 1992: An update, Supplement 3, Addendum 2

    International Nuclear Information System (INIS)

    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 July 1, 1992, through December 31, 1992. 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

  18. Yucca Mountain Site Characterization Project Bibliography, July, December 194: An update

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  20. Workshop on development of radionuclide getters for the Yucca Mountain waste repository: proceedings.

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Stephan, P.M. [ed.

    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.

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

    International Nuclear Information System (INIS)

    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

  5. Predictions of tracer transport in interwell tracer tests at the C-Hole complex. Yucca Mountain site characterization project report milestone 4077

    International Nuclear Information System (INIS)

    This report presents predictions of tracer transport in interwell tracer tests that are to be conducted at the C-Hole complex at the Nevada Test Site on behalf of the Yucca Mountain Site Characterization Project. The predictions are used to make specific recommendations about the manner in which the tracer test should be conducted to best satisfy the needs of the Project. The objective of he tracer tests is to study flow and species transport under saturated conditions in the fractured tuffs near Yucca Mountain, Nevada, the site of a potential high-level nuclear waste repository. The potential repository will be located in the unsaturated zone within Yucca Mountain. The saturated zone beneath and around the mountain represents the final barrier to transport to the accessible environment that radionuclides will encounter if they breach the engineered barriers within the repository and the barriers to flow and transport provided by the unsaturated zone. Background information on the C-Holes is provided in Section 1.1, and the planned tracer testing program is discussed in Section 1.2

  6. Interpretations of magnetic anomalies at a potential repository site located in the Yucca Mountain area, Nevada Test Site

    International Nuclear Information System (INIS)

    In the Yucca Mountain area near the southwestern border of the Nevada Test Site, studies of the relation of magnetic properties to geologic features have provided structural information at and near a potential site for storage or radioactive waste. Interpreted features include a tabular mass of magnetized sedimentary rock beneath thick deposits of volcanic rock, and 11 major faults that strike generally northward and displace magnetized volcanic rock. A positive anomaly in a high-altitude aeromagnetic survey over exposures of strongly magnetized argillite of the Eleana Formation extends westward 20 km into the site area where interpretations indicate an argillite thickness of 800 m at a depth of 2.25 km. The high magnetite content of the argillite is not typical of the region, and was probably introduced by the heating effects of an underlying pluton. The basis for mapping traces of faults, and identifying their upthrown sides, was developed elsewhere at Yucca fault in the relatively simple volcanic terrains of Yucca Flat. In the site area, analyses of aeromagnetic anomalies from a low-altitude east-west aeromagnetic survey show the Topopah Spring Member of the Paintbrush Tuff as the primary source of anomalies from faulted sequences of volcanic rock. Faults related to belts of positive and negative anomalies surrounding the site have been identified. The possibility that an east-west pattern of anomalies is related to structure crossing the site was investigated by a recent aeromagnetic survey flown at low altitude in north-south directions. A significant reduction in amplitude of these anomalies resulted when effects of the deeply buried argillite were removed. The remaining anomalies over the site can be explained by a change in lateral extent, or magnetic properties, of volcanic units beneath the Topopah Spring Member. 37 references, 22 figures, 1 table

  7. Evaluation of the geologic relations and seismotectonic stability of the Yucca Mountain Area, Nevada Nuclear Waste Site Investigation (NNWSI)

    International Nuclear Information System (INIS)

    This document describes activities for the year ending 30 June 1988 by staff members of the Seismological Laboratory in support of the Yucca Mountain site assessment program. Activities during the year centered largely around acquisition of equipment to be used for site assessment and around a review of the draft site characterization plan for Yucca Mountain. Due to modifications in the scheduling and level of funding, this work has not progressed as originally anticipated. The report describes progress in seven areas, listed in approximate order of significance to the Yucca Mountain project. These are: (1) equipment acquisition, (2) review of the draft site characterization plan, (3) studies of earthquake sequence related to the tectonic problems at Yucca Mountain, (4) a review of the work of Szymanski in relation to Task 4 concerns, (5) coordination meetings with USGS, DOE, and NRC personnel, (6) studies related to Yucca Mountain, and (7) other studies

  8. Radionuclide transport from yucca Mountain and Inter-basin Flow in Death Valley

    International Nuclear Information System (INIS)

    Hydrodynamics and the U.S. Geological survey conducted studies to evaluate far-field issues related to potential transport, by ground water, of radionuclide into Inyo County from Yucca Mountain, including Death Valley, and the evaluation of a connection between the Lower Carbonate Aquifer (LCA) and the biosphere. Our oversight and completed Cooperative Agreement research, and a number of other investigators research indicate that there is groundwater flow between the alluvial and carbonate aquifers both at Yucca Mountain and in Inyo County. The specific purpose of our research was to acquire geological, subsurface geology, and hydrologic data to: 1. Establish the existence of inter-basin flow between the Amargosa Basin and Death Valley Basin, 2. Characterize groundwater flow paths in the LCA through Southern Funeral Mountain Range, and 3. Evaluate the hydraulic connection between the Yucca Mountain repository and the major springs in Death Valley through the LCA. 4. Evaluate the hydraulic connection between the Yucca Mountain repository and Franklin Lake Playa. The hydraulic characterization of the LCA is of critical interest to Inyo County and the U.S. Department of Energy because: 1. The upward gradient in the LCA at Yucca Mountain provides a natural barrier to radionuclide transport, 2. The LCA is a necessary habitat resource for the endangered Devil's Hole pup fish, and 3. The LCA is the primary water supply and source of water to the major springs in Death Valley National Park. This paper presents the results of our study program to evaluate if inter-basin flow exists between the Amargosa and Death Valley Basins through the LCA. The study presents the results of our structural geology analysis of the Southern Funeral Mountain range, geochemical source analysis of spring waters in the region, and a numerical groundwater model to simulate inter-basin flow in the Southern Funeral Mountain range. (authors)

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

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

    International Nuclear Information System (INIS)

    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 groundwaterclose 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 fracturesclose 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 depositsclose 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Hill, C.A.; Schluter, C.M.; Harmon, R.S. [and others

    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.

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

    International Nuclear Information System (INIS)

    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

  13. Groundwater Flow and Thermal Modeling to Support a Preferred Conceptual Model for the Large Hydraulic Gradient North of Yucca Mountain

    International Nuclear Information System (INIS)

    Eleana Formation is absent at borehole UE-25 p No.1 at Yucca Mountain, which penetrated the lower Carbonate Aquifer directly beneath the lower volcanic confining unit. The Site-scale model uses an area of very low permeability, referenced as the east-west barrier, to simulate the large hydraulic gradient. The Site-scale model is further refined in this study to provide a base-case model for exploring the geologic causes of the large hydraulic gradient

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

  16. Today's Yucca mountain project and a new concept of multi-barrier system

    International Nuclear Information System (INIS)

    This paper mainly deals with the current status of Yucca Mountain project and the progress in study on engineering barrier in Belgium and introduces the future plan for Yucca Mountain project, two reports on draft supplemental environmental impact statement, and the view of New York Sen. Hillary Clinton and Illinois Sen. Barack Obama during the 2008 president elections related to the building a nuclear waste repository in Nevada. In order to enhance the security of geological disposal of high-level radioactive waste, a new concept about multi-barrier system is given by Belgium and is concisely described here. (authors)

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

    International Nuclear Information System (INIS)

    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

  18. Alternative assessments of the performance of the Yucca Mountain candidate HLW repository

    International Nuclear Information System (INIS)

    This paper summarizes some of the most recent total system performance assessment (TSPA) work supported by EPRI for the proposed repository at Yucca Mountain, Nevada. In part 1 of the paper, standard TSPA analyses are presented. In Part 2 examples of two types of analyses that augment standard TSPAs are provided that suggest: (1) many components of the Yucca Mountain system contribute to overall hazard reduction; and (2) the biosphere dose conversions used, based on reasonably maximizing assumptions about future human behavior, provide a reasonable upper bound. These additional analyses should provide further confidence when considering more standard TSPA analyses

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

    International Nuclear Information System (INIS)

    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. Assessment of the importance of mixing in the Yucca Mountain hydrogeological system

    International Nuclear Information System (INIS)

    The main objective of this work is to assess the importance of mixing on the hydrochemistry of waters in and around Yucca Mountain, most importantly in those waters south of Yucca Mountain. Due to the general north-south gradient of groundwater flow in the Yucca Mountain area, leakage from the proposed high-level radioactive waste repository would have the greatest consequences in the saturated zone waters south of Yucca Mountain. In this area (Amargosa River, Amargosa Flat and Ash Meadows), three main aquifers interact: the Regional Palaeozoic Carbonate Aquifer (RCA), the Tertiary Tuffs Aquifer (TTA) and the Quaternary Basin-fill Aquifer (QBfA). One consequence of upward leakage from the Palaeozoic Carbonate Aquifer would be to dilute the contaminant plume should one develop from the radioactive waste repository at Yucca Mountain. The reverse, downward leakage from the Tertiary Tuffs Aquifer or the Quaternary Basin-fill Aquifer into the Palaeozoic Carbonate Aquifer would contaminate a major aquifer system. It is clearly of the utmost importance to explore the links between theses aquifer systems and to assess the degree of mixing between the groundwaters. To attain this general objective, the following specific objectives have been either defined in advance or decided as being important during the development of the project: 1. Compile a dataset of water samples from the Yucca Mountain area. This dataset should contain samples from all the potential water types that contribute to the chemistry of the groundwaters in the aquifer systems in the area. 2. Perform a careful total-system exploratory analysis on the initial (raw) dataset in order to identify trends and outliers. 3. Perform a detailed exploratory analysis of each individual hydrofacies with the aim of identifying and eliminating from the raw dataset all the samples heavily affected by processes other than mixing (e.g. water-rock interaction, evaporation, cation exchange). PHREEQC simulations were

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  2. Saturation levels and trends in the unsaturated zone, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    The unsaturated zone at Yucca Mountain, Nevada, consists of interstratified nonwelded tuffs, which are locally altered to zeolites and clays, and welded tuffs which have laterally extensive lithophysal and nonlithophysal zones. The vertical heterogeneity and lateral homogeneity in rock types control the physical and hydrological properties. Water content and porosity within the unsaturated zone at Yucca Mountain can be quantified using geophysical logs. A log-based approach offers the advantage of in-situ measurements, continuous throughout a borehole. Water content and porosity can be determined with a pair of geophysical logs, such as the density and dielectric logs, as outlined in this paper

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

    International Nuclear Information System (INIS)

    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

  4. Assessment of the importance of mixing in the Yucca Mountain hydrogeological system

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, Javier B.; Auque, Luis F.; Gimeno, Maria; Acero, Patricia (Geochemical Modelling Group, Dept. of Earth Sciences, Univ. of Zaragoza (Spain)); Peterman, Zell; Oliver, Thomas A. (U.S. Geological Survey (United States)); Gascoyne, Mel (Gascoyne Geoprojects Inc (Canada)); Laaksoharju, Marcus (Geopoint AB (Sweden))

    2011-02-15

    The main objective of this work is to assess the importance of mixing on the hydrochemistry of waters in and around Yucca Mountain, most importantly in those waters south of Yucca Mountain. Due to the general north-south gradient of groundwater flow in the Yucca Mountain area, leakage from the proposed high-level radioactive waste repository would have the greatest consequences in the saturated zone waters south of Yucca Mountain. In this area (Amargosa River, Amargosa Flat and Ash Meadows), three main aquifers interact: the Regional Palaeozoic Carbonate Aquifer (RCA), the Tertiary Tuffs Aquifer (TTA) and the Quaternary Basin-fill Aquifer (QBfA). One consequence of upward leakage from the Palaeozoic Carbonate Aquifer would be to dilute the contaminant plume should one develop from the radioactive waste repository at Yucca Mountain. The reverse, downward leakage from the Tertiary Tuffs Aquifer or the Quaternary Basin-fill Aquifer into the Palaeozoic Carbonate Aquifer would contaminate a major aquifer system. It is clearly of the utmost importance to explore the links between theses aquifer systems and to assess the degree of mixing between the groundwaters. To attain this general objective, the following specific objectives have been either defined in advance or decided as being important during the development of the project: 1. Compile a dataset of water samples from the Yucca Mountain area. This dataset should contain samples from all the potential water types that contribute to the chemistry of the groundwaters in the aquifer systems in the area. 2. Perform a careful total-system exploratory analysis on the initial (raw) dataset in order to identify trends and outliers. 3. Perform a detailed exploratory analysis of each individual hydrofacies with the aim of identifying and eliminating from the raw dataset all the samples heavily affected by processes other than mixing (e.g. water-rock interaction, evaporation, cation exchange). PHREEQC simulations were

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

    International Nuclear Information System (INIS)

    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

  6. Release of radon contaminants from Yucca Mountain: The role of buoyancy driven flow

    International Nuclear Information System (INIS)

    The potential for the repository heat source to promote buoyancy driven flow and thereby cause release of radon gas out of Yucca Mountain has been examined through a critical review of the theoretical and experimental studies of this process. The review indicates that steady-state buoyancy enhanced release of natural radon and other contaminant gases should not be a major concern at Yucca Mountain. Barometric pumping and wind pumping are identified as two processes that will have a potentially greater effect on surface releases of gases

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

    International Nuclear Information System (INIS)

    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

  8. Modeling studies of mountain-scale radionuclide transport in the unsaturated zone at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Moridis, George J.; Seol, Yongkoo; Wu, Yu-Shu

    2003-04-29

    We investigate radionuclide transport from a high-level nuclear waste repository to be situated in the unsaturated zone (UZ) at Yucca Mountain (YM), Nevada. Several radioactive solutes (that cover the range of sorption behavior) and colloids of various sizes are studied. The results of the study indicate the importance of the subsurface geology and site hydrology, i.e., the presence of faults (they dominate and control transport), fractures (the main migration pathways), and the relative distribution of zeolitic and vitric tuffs. The effects of the climatic conditions, diffusion, and sorption (for solutes) or infiltration (for colloids) onto the matrix are discussed. The influence of the colloid size on transport is also investigated.

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

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    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

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. Los Alamos National Laboratory Yucca Mountain Site Characterization Project: 1991 quality program status report

    International Nuclear Information System (INIS)

    This status report summarizes the activities and accomplishments of the Los Alamos National Laboratory (Los Alamos) Yucca Mountain Site Characterization Project's (YMP) quality assurance program for calendar year 1991. The report is divided into three Sections: Program Activities, Verification Activities, and Trend Analysis

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

    International Nuclear Information System (INIS)

    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

  15. Distance learning and its application to the Yucca Mountain Site Characterization Project

    International Nuclear Information System (INIS)

    This paper discusses the concept of distance learning, which is used to exchange information via electronic media with real time interaction. Issues concerning policy, funding, legislation, accessibility, and programming are outlined. Possible applications for education, business, and federal projects, with a focus on the Yucca Mountain Site Characterization Project, are also discussed

  16. Literature review and ethnohistory of Native American occupancy and use of the Yucca Mountain Region

    International Nuclear Information System (INIS)

    This report presents a review of the literature concerning Native American occupancy and use of the Yucca Mountain area and vicinity. It draws on a wide range of material, including early traveler reports, government documents, ethnographic and historical works, and local newspapers. The report complements two other concurrent studies, one focused on the cultural resources of Native American people in the study area and the other an ethnobotanical study of plant resources used by Native American people in the study area. The literature review has had two principal purposes: to determine the completeness of the Yucca Mountain Native American study design and to contribute to the understanding of the presence of Native American people in the Yucca Mountain area. A review of the existing literature about the Yucca Mountain area and southern Nye County, supplemented by the broader literature about the Great Basin, has verified three aspects of the study design. First, the review has aided in assessing the completeness of the list of Native American ethnic groups that have traditional or historical ties to the site. Second, it has aided in the production of a chronology of Native American activities that occurred on or near the site during the late nineteenth and early twentieth centuries. Third, it has helped to identify the location of cultural resources, including burials and other archaeological sites, in the study area and vicinity. 200 refs., 16 figs., 6 tabs

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  18. Alternative strategies - a means for saving money and time on the Yucca Mountain Project

    International Nuclear Information System (INIS)

    The United States Department of Energy (DOE) is undertaking studies to determine the suitability of Yucca Mountain (YM) as a potential site for disposal of high-level nuclear waste. Yucca Mountain is located approximately 120 miles northwest of Las Vegas in an arid environment. Many processes that could contribute to mobilization of radionuclides are either absent or minimized in a dry site. Therefore, Yucca Mountain should have the potential of being a very favorable site for disposal of waste. However, the determination of suitability has no precedence, and the characterization of an arid site is complex, requiring intensive studies to determine suitability. The studies undertaken by the Yucca Mountain Site Characterization Project (YMP) are very costly. Unfortunately many people have concluded that the costs are so excessive that the project should not proceed, but rather should be curtailed. The author feels this is unfortunate for two reasons. First, the solution of what to do with nuclear waste is a clear and urgent national need if we are to have a balanced US energy strategy. Second, the excessive cost and lengthy schedule are in part artifacts of the strategy that has been developed for satisfying regulations and providing for isolation of the waste. It is this latter point that will be addressed in this paper

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  1. Results of multiple high-resolution geophysical surveys at Yucca Mountain

    International Nuclear Information System (INIS)

    Multiple high resolution seismic reflection, gravity, magnetic and magnetotelluric lines were acquired over and near the repository area during late 1994 and 1995. The goal was to define lithology, fault structure and fracturing to a depth of the repository horizon and below, if possible, for aiding in the overall characterization of Yucca Mountain. Initial geophysical results indicate a laterally heterogeneous faulted geologic system

  2. Unsaturated-zone fast-path flow calculations for Yucca Mountain GWTT analyses

    International Nuclear Information System (INIS)

    Sandia National Laboratories has developed calculational tools and modeling domains for groundwater-flow analyses; these tools are being used for evaluation of the Postclosure Geohydrology guideline in 10 CFR 960 [with emphasis on the Groundwater Travel Time (GWTT) disqualifying condition] for a potential nuclear waste repository at Yucca Mountain, NV. The emphasis of this work is on investigations of hydrologic processes and hydrogeologic features that may produce fast-path flow in the unsaturated zone (UZ) at Yucca Mountain. Based on the current understanding, conceptual models for UZ flow at Yucca Mountain generally assume that flow in fractures will be the mechanism for fastest water movement, and thus for fastest contaminant transport. The models used for these analyses require saturated conditions in the rock before UZ fracture flow can be initiated and sustained. This work investigates the initiation of fracture flow due to the creation of locally saturated zones in the unsaturated Yucca Mountain tuffs caused by natural heterogeneities in the rock units. For this purpose, we have developed model domain, using the composite-porosity flow model, where local saturation can be achieved without arbitrarily introducing saturated boundary conditions

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

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

    International Nuclear Information System (INIS)

    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+)2/Ca++) versus log a((Na+)2/Ca++) 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

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  6. Rainfall and net infiltration probabilities for future climate conditions at Yucca Mountain

    International Nuclear Information System (INIS)

    Performance assessment of repository integrity is a task rendered difficult because it requires predicting the future. This challenge has occupied many scientists who realize that the best assessments are required to maximize the probability of successful repository sitting and design. As part of a performance assessment effort directed by the EPRI, the authors have used probabilistic methods to assess the magnitude and timing of net infiltration at Yucca Mountain. A mathematical model for net infiltration previously published incorporated a probabilistic treatment of climate, surface hydrologic processes and a mathematical model of the infiltration process. In this paper, we present the details of the climatological analysis. The precipitation model is event-based, simulating characteristics of modern rainfall near Yucca Mountain, then extending the model to most likely values for different degrees of pluvial climates. Next the precipitation event model is fed into a process-based infiltration model that considers spatial variability in parameters relevant to net infiltration of Yucca Mountain. The model predicts that average annual net infiltration at Yucca Mountain will range from a mean of about 1 mm under present climatic conditions to a mean of at least 2.4 mm under full glacial (pluvial) conditions. Considerable variations about these means are expected to occur from year-to-year

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

    Energy Technology Data Exchange (ETDEWEB)

    None

    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.

  8. Environmental assessment: Yucca Mountain site, Nevada research and development area, Nevada

    International Nuclear Information System (INIS)

    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

  9. Environmental assessment: Yucca Mountain Site, Nevada Research and Development Area, Nevada

    International Nuclear Information System (INIS)

    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

  10. Environmental assessment: Yucca Mountain site, Nevada research and development area, Nevada

    International Nuclear Information System (INIS)

    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

  11. Alternative strategies: A means for saving money and time on the Yucca Mountain Project

    International Nuclear Information System (INIS)

    The United States Department of Energy (DOE) is undertaking studies to determine the suitability of Yucca Mountain (YM) as a potential site for disposal of high level nuclear waste. Yucca Mountain is located in an arid environment. Many processes that could contribute to mobilization of radionuclides are either absent or minimized in a dry site. Therefore, Yucca Mountain should have the potential of being a veryfavorable site for disposal of waste. The determination of suitability has no precedence, and the characterization of an and site is complex, requiring intensive studies to determine suitability. The studies undertaken by the Yucca Mountain Site Characterization Project (YMP) are very costly. By a process called performance allocation, the YMP determined strategies to satisfy regulations or meet performance while minimizing costs and schedules. Those involved recognized that allocations should be reviewed as additional information became available. The allocation has not been reviewed nor revised since the initial allocation in the Site Characterization Plan (SCP). The purpose of this paper is to outline alternative allocations that the author feels should be considered based on the additional information that is available at this time

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

    Science.gov (United States)

    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.

  13. DOE's Yucca Mountain studies: What are they? Why are they being done?

    International Nuclear Information System (INIS)

    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

  14. Conceptual hydrologic model of flow in the unsaturated zone, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    The purpose of this report is to propose a conceptual hydrologic model that reasonably describes the flow of fluids through the unsaturated zone at Yucca Mountain, for use as a basis for preliminary site-performance assessment and as a guide to further investigations. Scott and others (1983) presented an initial conceptual hydrogeologic model for the unsaturated zone at Yucca Mountain, based on detailed geologic, but very limited hydrologic, information. In this report, some of their concepts are examined and either supported or modified, and new concepts are developed. The model describes the manner in which flow probably occurs at Yucca Mountain and is based on: (1) current understanding of the hydrogeologic framework; (2) application of the principles of unsaturated flow; and (3) interpretation of some preliminary data from ongoing field and laboratory investigations. Included are extensive geologic information but relatively few hydrologic data that currently exist from the unsaturated zone in the Yucca Mountain area. Many uncertainties remain to be resolved concerning hydrologic conditions and processes. As a result, most of the concepts presented are intentionally descriptive and conjectural, with little quantitative basis provided. However, for the sake of directness and simplicity of expression, the model is presented as if it were a true expression of the facts. The authors recognize, and the reader should be aware, that the proposed model probably is not the only reasonable description that could be made at this point, and it certainly is subject to revision and quantification as more data become available. Although various alternative models probably could be developed, the one described in this report seems to fit current understanding of the unsaturated flow through a section of layered, fractured-rock formations with contrasting hydrologic properties, such as occurs at Yucca Mountain. 41 refs., 14 figs., 1 tab

  15. Major results of gravity and magnetic studies at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    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. Considerable aeromagnetic coverage of southwestern Nevada was obtained in 1978-79 to help characterize Yucca Mountain and vicinity. One significant result is the discovery of a series of circular magnetic anomalies in Crater Flat and the northern Amargosa Desert that suggest the presence of buried volcanic centers there. If this interpretation is confirmed by drilling, the magnetic data can be used to help estimate the total volume of buried volcanic rocks, which, along with radiometric dating, could help provide a better prediction of future volcanism. Elongate magnetic highs and associated lows over Yucca Mountain correlate with mapped faults, some of which are only partially exposed. Thus, the data provide information on the extent and continuity of these faults

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

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

    International Nuclear Information System (INIS)

    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

  19. As Yucca Mountain debate continues, industry calls for 'comprehensive' solution

    Energy Technology Data Exchange (ETDEWEB)

    Mitev, Lubomir [NucNet, Brussels (Belgium)

    2014-12-15

    The proposed Nevada site Yucca Mountain is still the only game in town for a deep geologic repository in the US, but resolving the uncertainty that surrounds the project could still take years, making centralised temporary storage more important than ever. The nuclear industry in the US has renewed a call for 'a more comprehensive nuclear fuel management system' that includes the development of centralised temporary storage while the licensing process for a deep geologic repository at Yucca Mountain in Nevada continues. Scott Peterson, senior vice-president for communications of the Washington-based Nuclear Energy Institute, told that centralised temporary storage would allow the removal of spent fuel from reactor sites, especially from reactors that have already shut down, while uncertainty surrounding the Yucca Mountain deep geologic project is resolved. Resolving that uncertainty could take time. The Yucca Mountain project has been shut down by the Department of Energy (DOE) since 2010 and there is no work going on right now at the repository site or on the DOE's part to continue licensing activities. The outcome of mid-term elections on 4 November could yet see the political manoeuvrings surrounding Yucca Mountain take another twist. The Republican party takes control of the Senate. There will be an opportunity to change the funding profile for the NRC and to take measures through legislation to make sure the DOE is following the 1982 Nuclear Waste Policy Act. This Act, which made the DOE responsible for finding a site, building, and operating an underground geologic repository, is still in force.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  3. Geological history of Yucca Mountain (Nevada) and the problem of a high-level nuclear waste repository

    International Nuclear Information System (INIS)

    Three types of deposits are widely distributed throughout the Yucca Mountain unsaturated zone: mosaic breccias, quartz-calcite veinlets, and micritic opal-calcite veins and associated slope deposits were found to be of hydrothermal origin. The inference is based on petrographic, accessory mineral, fluid inclusion, and stable isotopic data. The overall conclusion is that recurrent low-temperature hydrothermal (epithermal) activity occurred at Yucca Mountain in the geologically recent past (from ca. 8-10 Ma to as recently as 25 ka). New data require the currently- accepted concept of the hydrogeological system at Yucca Mountain to be reconsidered. The subject relates to the suitability of Yucca Mountain as a high-level nuclear waste site. 21 refs

  4. Sequential evaluation of the potential geologic repository site at Yucca Mountain, Nevada, U.S.A

    International Nuclear Information System (INIS)

    1996 will be remembered as a year of transition, even upheaval, for the United States' program for geologic disposal of spent reactor fuel and high-level nuclear wastes from military reprocessing. The 1996 budget for the U.S. Department of Energy's (DOE) Office of Civilian Radioactive Waste Management (OCRWM) combined with reduced funding levels anticipated through the end of the decade make it necessary to substantially modify the United States' waste management program. The two major changes DOE has made in response to the 1996 budget involve, 1) resequencing the technical and statutory milestones for Yucca Mountain characterization, and 2) terminating further development of most waste acceptance activities, multi-purpose canister development, and generic transportation work. Budget reductions combine with legislation now before the 104th U. S. Congress that, if it is signed into law, would redirect the program to authorize temporary storage of waste at an interim storage facility and de-emphasize long-term disposal and isolation. This paper explains the changes that are being planned for the characterization program at Yucca Mountain. Yucca Mountain, Nevada is the only site being studied in the United States for a geologic repository: an arid terrane of 12 million-year-old unsaturated, stratiform volcanic tuff. Funding for the site characterization program at Yucca Mountain for l996 was cut by roughly one half from that anticipated in 1994 as needed to complete three major milestones by 2001. These project milestones included, 1) a time-phased determination of Site Suitability, and if a positive finding, 2) completion of an Environmental Impact Statement, and 3) preparation of a License Application to the U.S. Nuclear Regulatory Commission (NRC) to authorize repository construction. In reaction, the Yucca Mountain Site Characterization Project has shifted from parallel development of these milestones to a sequenced approach with the Site Suitability Evaluation

  5. The impact of episodic nonequilibrium fracture-matrix flow on repository performance at the potential Yucca Mountain site

    International Nuclear Information System (INIS)

    Adequate representation of fracture-matrix interaction during episodic infiltration events is crucial in making valid hydrological predictions of repository performance at Yucca Mountain. Approximations have been applied to represent fracture-matrix flow interaction, including the Equivalent Continuum Model, which assumes capillary equilibrium between fractures and matrix, and the Fracture-Matrix Model, which accounts for nonequilibrium fracture-matrix flow and transport for the eight major hydrostratigraphic units in the unsaturated zone at Yucca Mountain. 18 refs., 6 figs., 3 tabs

  6. Post-Closure Silica Transport in the Proposed High Level Radioactive Waste Repository at Yucca Mountain, Nevada

    OpenAIRE

    Sun, Zhuang

    1997-01-01

    The United States plans to bury high level radioactive waste from commercial power reactors and from nuclear weapons manufacturing in Yucca Mountain, Nevada. Yucca Mountain, located about 80 miles northwest of Las Vegas, consists of horizontally bedded tuff deposits. Although the region is very arid, enough water exists in the tuffs to create a vapor dominated geothermal system as the pore water evaporates, circulates and recondenses. This study examines how silica leaching might occur as a r...

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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

  10. Fabrication and closure development of nuclear waste containers for storage at the Yucca Mountain, Nevada repository

    International Nuclear Information System (INIS)

    US Congress and the President have determined that the Yucca Mountain site in Nevada is to be characterized to determine its suitability for construction of the first US high-level nuclear waste repository. Work in connection with this site is carried out within the Yucca Mountain Project (YMP). Lawrence Livermore National Laboratory (LLNL) has the responsibility for designing, developing, and projecting the performance of the waste package for the permanent storage of high-level nuclear waste. Babcock ampersand Wilcox (B ampersand W) is involved with the YMP as a subcontractor to LLNL. B ampersand W's role is to recommend and demonstrate a method for fabricating the metallic waste container and a method for performing the final closure of the container after it has been filled with waste. Various fabrication and closure methods are under consideration for the production of containers. This paper presents progress to date in identifying and evaluating the candidate manufacturing processes. 2 refs., 1 fig., 7 tabs

  11. Yucca Mountain Project: Preliminary shaft liner design criteria and methodology guide

    International Nuclear Information System (INIS)

    The Shaft Liner Design Criteria and Methodology Guide outlines a methodology for designing concrete shaft liners for the Yucca Mountain Project repository in tuff, the use of which will ensure that all shafts meet the requirements for repository service. These requirements are identified in the guide; then, unlined shaft behavior is examined to establish rock behavior modes and to investigate the development of convergence during construction. Ground pressure and induced thermal and seismic loads imposed on the shaft liner are evaluated. The modes of deformation resulting from loading, which include bending, shear, hoop deformation, and axial strain, are analyzed following a working stress approach that uses closed-form interaction models. Predicted liner stresses are then evaluated using allowable stress criteria. The methodology is illustrated with examples appropriate to the repository site at Yucca Mountain. 43 refs., 35 figs., 25 tabs

  12. Borehole and geohydrologic data for test hole USW UZ-6, Yucca Mountain area, Nye County, Nevada

    International Nuclear Information System (INIS)

    Test hole USW UZ-6, located 1.8 kilometers west of the Nevada Test Site on a major north-trending ridge at Yucca Mountain, was dry drilled in Tertiary tuff to a depth of 575 meters. The area near this site is being considered by the US Department of Energy for potential construction of a high-level, radioactive-waste repository. Test hole USW UZ-6 is one of seven test holes completed in the unsaturated zone as part of the US Geological Survey's Yucca Mountain Project to characterize the potential repository site. Data pertaining to borehole drilling and construction, lithology of geologic units penetrated, and laboratory analyses for hydrologic characteristics of samples of drill-bit cuttings are included in this report

  13. Three-dimensional hydrological and thermal property models of Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Rautman, C.A.; McKenna, S.A. [Sandia National Labs., Albuquerque, NM (United States). Geohydrology Dept.

    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.

  14. Waste package/engineered barrier system design concepts for Yucca Mountain repository

    International Nuclear Information System (INIS)

    The U.S. Department of Energy (DOE) is responsible for the siting, construction and operation of mined geologic disposal system (MGDS) for high level waste. The U.S. Nuclear Regulatory Commission (NRC) has the responsibility for promulgating the technical requirements necessary to license all phases of repository operation. The development of MGDS has been delegated to the DOE's Yucca Mountain Site Characterization Project Office. The B ampersand W Fuel Company, as part of the Civilian Radioactive Waste Management System Management and Operating Contractor, is responsible for designing the waste package (WP) and the engineered barrier system (EBS). The goal of the design effort is to achieve a conservative, licensable design that meets the regulatory requirements with sufficient margin for uncertainty. Attainment of this goal relies on a multibarrier approach, the unsaturated nature of the Yucca Mountain site, consideration of, technical alternatives, and sufficient resolution of technical and regulatory uncertainties

  15. Site characterization plan: Yucca Mountain Site, Nevada Research and Development Area, Nevada: Volume 9, Index

    International Nuclear Information System (INIS)

    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

  16. Parallel computing simulation of fluid flow in the unsaturated zone of Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    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

  17. Three-dimensional hydrological and thermal property models of Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    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

  18. Site characterization progress report, Yucca Mountain, Nevada. Number 19, April 1, 1998 - September 30, 1998

    International Nuclear Information System (INIS)

    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

  19. Fracture analysis and rock quality designation estimation for the Yucca Mountain Site Characterization Project

    International Nuclear Information System (INIS)

    Within the Yucca Mountain Site Characterization Project, the design of drifts and ramps and evaluation of the impacts of thermomechanical loading of the host rock requires definition of the rock mass mechanical properties. Ramps and exploratory drifts will intersect both welded and nonwelded tuffs with varying abundance of fractures. The rock mass mechanical properties are dependent on the intact rock properties and the fracture joint characteristics. An understanding of the effects of fractures on the mechanical properties of the rock mass begins with a detailed description of the fracture spatial location and abundance, and includes a description of their physical characteristics. This report presents a description of the abundance, orientation, and physical characteristics of fractures and the Rock Quality Designation in the thermomechanical stratigraphic units at the Yucca Mountain site. Data was reviewed from existing sources and used to develop descriptions for each unit. The product of this report is a data set of the best available information on the fracture characteristics

  20. Preservation of archaeological materials in arid environments: Analogues relevant to Yucca Mountain

    International Nuclear Information System (INIS)

    The potential repository at Yucca Mountain in Nevada is in an arid area, in unsaturated volcanic tuff with oxidising conditions, and may be kept open and ventilated for hundreds of years. Existing US work on archaeological material and structural analogues in such conditions has been extended to seek further well-preserved objects in such conditions. The objectives of the study are partly scientific and partly aimed at the public. A wide range of exceptionally well-preserved glass, metal and organic materials is found in the archaeological record from sites that have been characterised by arid conditions for many thousands of years. Underground preservation environments include those either continuously open (caves) or sealed but not 'backfilled' (tombs). Preservation of materials in such openings provides a useful analogue reference point for considering the operation and evolution of the Yucca Mountain repository. (author)

  1. Site characterization plan: Yucca Mountain Site, Nevada Research and Development Area, Nevada: Volume 9, Index

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  2. Los Alamos National Laboratory Yucca Mountain Site Characterization Project 1994 quality program status report

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Calibration of Yucca Mountain unsaturated zone flow and transport model using porewater chloride data

    OpenAIRE

    Liu, Jianchun; Sonnenthal, Eric L.; Bodvarsson, Gudmundur S.

    2002-01-01

    In this study, porewater chloride data from Yucca Mountain, Nevada, are analyzed and modeled by 3-D chemical transport simulations and analytical methods. The simulation modeling approach is based on a continuum formulation of coupled multiphase fluid flow and tracer transport processes through fractured porous rock, using a dual-continuum concept. Infiltration-rate calibrations were using the pore water chloride data. Model results of chloride distributions were improved in matching the...

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

    International Nuclear Information System (INIS)

    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

  5. Application of heavy duty roadheaders for underground development of the Yucca Mountain Exploratory Study Facility

    International Nuclear Information System (INIS)

    Heavy duty roadheaders of 100 ton weight class are being considered for the excavation of the test rooms and alcoves along the main ramp and in the main repository level at the Yucca Mountain site. The current design of the candidate machines was studied and appropriate modifications are proposed. Computer programs for design optimization and performance prediction of roadheaders were developed. Results of computer modeling and operational parameters of the proposed machines are presented in this paper

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

    International Nuclear Information System (INIS)

    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 (-7 events per year. Bounding probability estimates are used to assess possible implications of not drilling aeromagnetic anomalies in the Arnargosa Valley and Crater Flat. The results of simulation modeling are used to assess the sensitivity of the disruption probability for the location of northeast boundaries of volcanic zones near the Yucca Mountain site. A new section on modeling of radiological releases associated with surface and subsurface magmatic activity has been added to chapter 6. The modeling results are consistent with past total system performance assessments that show future volcanic and magmatic events are not significant components of repository performance and volcanism is not a priority issue for performance assessment studies

  7. Evaluation of uncertainty in geological framework models at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    The first step towards determining compliance with the performance objectives for both the repository system and the geologic setting at Yucca Mountain requires the development of detailed geostratigraphic models. This paper proposes an approach for the evaluation of the degree of uncertainty inherent in geologic maps and associated three-dimensional geological models. Following this approach, an assessment of accuracy and completeness of the data and evaluation of conceptual uncertainties in the geological framework models can be performed

  8. Regulatory Framework for the Geologic Repository at Yucca Mountain Nevada, USA

    International Nuclear Information System (INIS)

    After years of geologic investigations, Yucca Mountain, Nevada has been recommended by the President of the United States and approved by the U.S. Congress for development as a geologic repository for disposal of high-level radioactive waste and spent nuclear fuel. This significant step forward in implementing national policy for the safe and environmentally sound isolation of radioactive waste was made possible, in part, by the finalization of the regulatory framework for the U.S. repository program. The Nuclear Waste Policy Act, passed in 1982 and amended in 1987, established the roles of three federal agencies responsible for interrelated regulatory aspects of radioactive waste disposal: (1) the U.S. Environmental Protection Agency (''EPA''; responsible for setting standards for public health and environmental protection); (2) the U.S. Nuclear Regulatory Commission (''NRC''; responsible for developing licensing criteria and regulations implementing the EPA's standard); and, (3) the U.S. Department of Energy (''DOE''; responsible for site selection, characterization, recommendation and repository development and operation). These agencies first published their regulations in the 1980's. In the 1992 Energy Policy Act, Congress directed the EPA to develop new public health and safety standards that were specific for Yucca Mountain and directed the NRC to revise its technical requirements and criteria to be consistent with the EPA's new standard. In keeping with this approach, DOE adopted site suitability guidelines to apply to Yucca Mountain. Therefore, with the 2001 finalization of the EPA standard and the NRC and DOE regulations, the regulatory framework for a Yucca Mountain repository is in place

  9. Los Alamos National Laboratory Yucca Mountain Site Characterization Project 1994 quality program status report

    International Nuclear Information System (INIS)

    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

  10. Interpretation of chemical and isotopic data from boreholes in the unsaturated zone at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    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 CO2 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

  11. Chemical variability of zeolites at a potential nuclear waste repository, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    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

  12. Data Qualification Report: Precipitation and Surface Geology Data for Use on the Yucca Mountain Project

    International Nuclear Information System (INIS)

    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

  13. Water levels in the Yucca Mountain area, Nevada, 1990--91

    International Nuclear Information System (INIS)

    Water levels were monitored in 27 wells in the Yucca Mountain area, Nevada during 1990--91. Twelve wells were monitored periodically, generally on a monthly basis, and 15 wells representing 24 intervals were monitored hourly. All wells monitor water levels in Tertiary volcanic rocks, except one that monitors 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 1,035 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 1990--91. All data were acquired in accordance with a quality-assurance program to support the reliability of the data

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

    International Nuclear Information System (INIS)

    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 ampersand G Energy Measurements, Inc., Las Vegas, NV (EG ampersand 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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  16. Strontium isotope geochemistry of soil and playa a deposits near Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    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

  17. Paleoseismic investigations of Stagecoach Road fault, southeastern Yucca Mountain, Nye County, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Movement of shaft and drift construction water in Yucca Mountain, Nevada: An extended study

    International Nuclear Information System (INIS)

    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

  19. Evaporation of J13 and UZ pore waters at Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    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).

  20. Comparison of sealing strategy for the Yucca Mountain project with sealing for other repository programs

    International Nuclear Information System (INIS)

    The sealing concept for Yucca Mountain involves inhibiting water entry to the repository, maintaining free drainage from waste emplacement areas, and sealing of penetrations through the stratigraphic barriers to radionuclide transport. Sealing will accommodate possible site conditions such as perched water, and expected repository effects such as far-field mobilization of water by waste-generated heat. Scenarios for disruption of hydrologic conditions by increased flux from surface infiltration, and by flooding of the repository, will be among a range of disruptive scenarios considered in assessment of sealing performance. Basic differences between saturated vs. unsaturated zone sealing concepts can be expressed in terms of variations of some basic characteristics among different sites and host media. Despite the apparent differences, much of the work ongoing internationally in the area of sealing technology is applicable to the Yucca Mountain site. The schedule for concept development, laboratory and field studies, and seal design and implementation at Yucca Mountain is consistent with continued cooperation, and can make use of future technological developments

  1. Potential fast paths along faults in the Calico Hills unit at Yucca Mountain

    International Nuclear Information System (INIS)

    Potential fast flow and transport paths comprising near vertical fractures or faults are one of the most important features affecting the suitability of Yucca Mountain as a site for a potential permanent repository of high-level radioactive waste. Of the unsaturated tuff units at Yucca Mountain, the Calico hills nonwelded tuff unit is relatively less fractured and is further away from repository-induced perturbations, in comparison with the Topopah Spring welded tuff units. Observations in the Tunnel Bed units from the Defense Nuclear Agency tunnels at Rainier Mesa indicate that major flow paths have short travel times for the transport of meteoric water through the vadose zone, and the potential fast path features are spatially infrequent. The presence of similiar fast paths cannot be ruled out by existing borehole data from Yucca Mountain. In this study, the vertical and lateral distribution of vitric and zeolitic tuff sections in the Calico Hills unit above the water table, and the vitrophyre at the base of the Topopah Spring unit are evaluated

  2. Preclosure seismic design methodology for a geologic repository at Yucca Mountain. Revision 1

    International Nuclear Information System (INIS)

    This topical report is the second in a series of three reports being developed by the US Department of Energy (DOE) to document the preclosure seismic design of structures, systems, and components (SSCs) that are important to the radiological safety of the potential repository at Yucca Mountain, Nevada. The first topical report, Methodology to Assess Fault Displacement and Vibratory Ground Motion Hazards at Yucca Mountain, YMP/TR-002-NP, was submitted to the US Nuclear Regulatory Commission (NRC) staff for review and comment in 1994 and has been accepted by the staff. The DOE plans to implement this methodology in fiscal year 1997 to develop probabilistic descriptions of the vibratory ground motion hazard and the fault displacement hazard at the Yucca Mountain site. The second topical report (this report) describes the DOE methodology and acceptance criteria for the preclosure seismic design of SSCs important to safety. A third report, scheduled for fiscal year 1998, will document the results of the probabilistic seismic hazard assessment (conducted using the methodology in the first topical report) and the development of the preclosure seismic design inputs. This third report will be submitted to NRC staff for review and comment as a third topical report or as a design study report

  3. Shallow infiltration processes at Yucca Mountain, Nevada: Neutron logging data 1984--1993

    International Nuclear Information System (INIS)

    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

  4. Shallow infiltration processes at Yucca Mountain, Nevada - neutron logging data 1984-93

    International Nuclear Information System (INIS)

    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

  5. Yucca Mountain Site Characterization Project bibliography, 1992--1994. Supplement 4

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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).

  6. The role of fault zone in affecting multiphase flow at Yucca Mountain

    International Nuclear Information System (INIS)

    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 C14. The results of this study also focus attention on the need for field measurements of fluid flow in the fault zones

  7. The role of fault zones in affecting multiphase flow at Yucca Mountain

    International Nuclear Information System (INIS)

    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 C14. The results of this study also focus attention on the need for field measurements of fluid flow in the fault zones

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

    International Nuclear Information System (INIS)

    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

  9. Physical processes and effects of magmatism in the Yucca Mountain region

    International Nuclear Information System (INIS)

    Initial studies related to the effects of volcanism on performance of the potential Yucca Mountain radioactive waste repository, and to the general processes of magmatism in the Yucca Mountain region, are described. 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 have 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. In this paper 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. The authors 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. Fractures in outcrops in the vicinity of drill hole USW G-4, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Fractures on outcrops in the vicinity of drill hole USW G-4, Yucca Mountain, Nevada, were studied in order to contribute to characterization of fractures for hydrologic, geomechanical, and tectonic modeling of the Yucca Mountain block and to characterize fractures prior to the excavation of a proposed exploratory shaft located near USW G-4. Yucca Mountain is a prospective site for the construction of an underground repository for high-level nuclear waste. Measurements were taken and recorded on 5000 fractures at 50 outcrop stations primarily in the upper lithophysal unit of the Tiva Canyon Member of the Miocene Paintbrush Tuff. Fracture orientation and surface roughness were recorded for each fracture. Additionally, notes were taken on fracture abutting, crossing, and offsetting relations, swarming, curvature, brecciation, slickensides, and fracture fillings. Frequency distributions of orientation and roughness were plotted and analyzed. Fractures with low roughness coefficients (0-4) group tightly into two sets based on orientation. We conclude that such fractures are cooling joints and that all other fractures are tectonic. The development of small-scale fractures adjacent, subparallel, and possibly related to the Ghost Dance fault has been addressed in a preliminary way based on data collected in this study. Such sympathetic fractures are abundant in the upper cliff unit but not in the upper lithophysal unit. 14 refs., 6 figs., 1 tab

  11. Analysis of the elastic and strength properties of Yucca Mountain tuff, Nevada

    International Nuclear Information System (INIS)

    Yucca Mountain, located near the southwest margin of the Nevada Test Site, in southern Nevada, is being evaluated as a potential site for a nuclear waste repository. Yucca Mountain consists primarily of layered volcanic tuff. Samples from four stratigraphic units have been tested for physical, thermal and mechanical properties as part of the Nevada Nuclear Waste Storage Investigations (NNWSI) Project, administered by the Nevada Operations Office of the U.S. Department of Energy. The four units, in order of increasing depth, are as follows: (1) Topopah Spring Member of the Paintbrush Tuff, (2) Tuffaceous Beds of Calico Hills, (3) Bullfrog Member of the Crater Flat Tuff, and (4) Tram Member of the Crater Flat Tuff. A large data base from more than 100 experiments on drillhole core samples of Yucca Mountain silicic tuff has been assembled for use in NNWSI site evaluation and repository design calculations. These data have been analyzed and empirical expressions were found which relate elastic properties and strength with porosity plus clay content. These relationships will be presented here, in addition to an application of simple elastic composite theory to explain the observed variation of bulk modulus with functional porosity

  12. Yucca Mountain Site Characterization Project bibliography, 1992--1993. Supplement 4

    International Nuclear Information System (INIS)

    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)

  13. Water levels in the Yucca Mountain area, Nevada, 1990--91

    Energy Technology Data Exchange (ETDEWEB)

    Tucci, P.; O`Brien, G.M.; Burkhardt, D.J.

    1996-07-01

    Water levels were monitored in 27 wells in the Yucca Mountain area, Nevada during 1990--91. Twelve wells were monitored periodically, generally on a monthly basis, and 15 wells representing 24 intervals were monitored hourly. All wells monitor water levels in Tertiary volcanic rocks, except one that monitors 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 1,035 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 1990--91. All data were acquired in accordance with a quality-assurance program to support the reliability of the data.

  14. 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

    International Nuclear Information System (INIS)

    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

  15. Bedrock geologic map of the Yucca Mountain area, Nye County, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Day, W.C.; Potter, C.J.; Sweetkind, D.S.; Fridrich, C.J. [Geological Survey, Denver, CO (US); Dickerson, R.P.; San Juan, C.A.; Drake, R.M. II [Pacific Western Technologies, Inc., Denver, CO (US)

    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.

  16. 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

    Energy Technology Data Exchange (ETDEWEB)

    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

  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

    International Nuclear Information System (INIS)

    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 the 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. Experimental and numerical simulation of dissolution and precipitation: implications for fracture sealing at Yucca Mountain, Nevada.

    Science.gov (United States)

    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

  19. US Geological Survey Committee for the Advancement of Science in the Yucca Mountain Project symposium on open-quotes Fractures, Hydrology, and Yucca Mountainclose quotes: Abstracts and summary

    International Nuclear Information System (INIS)

    The principal objective of this symposium is to review the available information on fractured/faulted terrains in terms of a coherent hydrogeologic model of ground-water fluid flow and transport, particularly as it pertains to the Yucca Mountain region. This review addresses the influence and significance of fractures on ground-water flow and the transport of conservative-species solutes within the context of the hydrogeologic setting of the Yucca Mountain area. The relations between fluid flow and fractured or faulted host rock are examined integrally from information on geologic, seismologic, hydrologic, and geomechanical properties of the system. The development of new hydrogeologic approaches that incorporate information from this integrated database are contrasted with more standard approaches toward understanding flow in fractured reservoirs. Ground-water flow in both the unsaturated zone and the saturated zone are considered. The application of various models of flow is addressed, examples include porous-media equivalent and discontinuum fracture-network models. Data and interpretations from the Yucca Mountain area are presented to establish a context for information exchange. The symposium includes discussions relevant to technical considerations for characterizing the Yucca Mountain area hydrogeology. On the basis of these discussions, CASY has compiled this document in order to formally summarize the proceedings and communicate recommendations for future directions of research and investigation

  20. Isotope-Geochemical Evidence For Uranium Retardation in Zeolitized Tuffs at Yucca Mountain, Nevada, USA

    International Nuclear Information System (INIS)

    Retardation of radionuclides by sorption on minerals in the rocks along downgradient groundwater flow paths is a positive attribute of the natural barrier at Yucca Mountain, Nevada, the site of a proposed high-level nuclear waste repository. Alteration of volcanic glass in nonwelded tuffs beneath the proposed repository horizon produced thick, widespread zones of zeolite- and clay-rich rocks with high sorptive capacities. The high sorptive capacity of these rocks is enhanced by the large surface area of tabular to fibrous mineral forms, which is about 10 times larger in zeolitic tuffs than in devitrified tuffs and about 30 times larger than in vitric tuffs. The alteration of glass to zeolites, however, was accompanied by expansion that reduced the matrix porosity and permeability. Because water would then flow mainly through fractures, the overall effectiveness of radionuclide retardation in the zeolitized matrix actually may be decreased relative to unaltered vitric tuff. Isotope ratios in the decay chain of 238U are sensitive indicators of long-term water-rock interaction. In systems older than about 1 m.y. that remain closed to mass transfer, decay products of 238U are in secular radioactive equilibrium where 234U/238U activity ratios (AR) are unity. However, water-rock interaction along flow paths may result in radioactive disequilibrium in both the water and the rock, the degree of which depends on water flux, rock dissolution rates, α-recoil processes, adsorption and desorption, and the precipitation of secondary minerals. The effects of long-term water-rock interaction that may cause radionuclide retardation were measured in samples of Miocene-age subrepository zeolitized tuffs of the Calico Hills Formation (Tac) and the Prow Pass Tuff (Tcp) from borehole USW SD-9 near the northern part of the proposed repository area (sampled depth interval from 451.1 to 633.7 m; Engstrom and Rautman, 1996). Mineral abundances and whole-rock chemical and U-series isotopic

  1. Ground-water recharge in Fortymile Wash near Yucca Mountain, Nevada, 1992-93

    International Nuclear Information System (INIS)

    Ground-water recharge occurred after five separate streamflow event periods in the Pah Canyon area of Fortymile Wash approximately 10 kilometers from Yucca Mountain, Nevada during 1992-93. Ground-water levels rose in two wells, UE-29 a No.1 and UE-29 a No.2, and one neutron-access borehole, UE-29 UZN-91, after each streamflow event period. A maximum rise of 2.9 meters occurred at UE-29 a No.1 thirteen days after the largest streamflow event where depth to water changed from 27.3 to 24.4 meters. Water levels fluctuated 3.89 meters in UE-29 a No.1, 2.92 meters in UE-29 a No.2, and 2.10 meters in UE-29 UZN-91 during the period January, 1992 to September, 1993. During two of the streamflow event periods, one in 1992 and one in 1993, there was flow around the neutron-access borehole located in the Fortymile Wash channel. Three other streamflow event periods were documented in Pah Canyon Wash but the streamflow infiltrated prior to reaching the neutron-access borehole location. Volumetric-water-content profiles were measured periodically in the neutron-access borehole. After the 1992 streamflow event period, water content increased in the upper six meters of the unsaturated zone. After the 1993 streamflow event period, water content increased in the entire unsaturated section, approximately 16 meters thick at the neutron-access borehole. Water levels in the neutron-access borehole rose even when there was no apparent water movement through the unsaturated zone as inferred by changes in the volumetric-water contents. This rise is attributed to ground-water recharge from nearby infiltration of Pah Canyon Wash streamflow. A groundwater mound probably formed beneath Pah Canyon Wash and spread laterally as evidence by larger rises in water levels in UE-29 a No.1 and UE-29 a No.2, which are closer to Pah Canyon Wash than UE-29 UZN-91

  2. Temporal Damping Effect of the Yucca Mountain Fractured Saturated Rock on Transient Infiltration Pulses

    International Nuclear Information System (INIS)

    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

  3. Preliminary model of the pre-Tertiary basement rocks beneath Yucca Flat, Nevada Test Site, Nevada, based on analysis of gravity and magnetic data

    Science.gov (United States)

    Phelps, Geoffrey A.; McKee, Edwin H.; Sweetkind, D.; Langenheim, V.E.

    2000-01-01

    The Environmental Restoration Program of the U.S. Department of Energy, Nevada Operations Office, was developed to investigate the possible consequences to the environment of 40 years of nuclear testing on the Nevada Test Site. The majority of the tests were detonated underground, introducing contaminants into the ground-water system (Laczniak and others, 1996). An understanding of the ground-water flow paths is necessary to evaluate the extent of ground-water contamination. This report provides information specific to Yucca Flat on the Nevada Test Site. Critical to understanding the ground-water flow beneath Yucca Flat is an understanding of the subsurface geology, particularly the structure and distribution of the pre-Tertiary rocks, which comprise both the major regional aquifer and aquitard sequences (Winograd and Thordarson, 1975; Laczniak and others, 1996). Because the pre-Tertiary rocks are not exposed at the surface of Yucca Flat their distribution must be determined through well logs and less direct geophysical methods such as potential field studies. In previous studies (Phelps and others, 1999; Phelps and Mckee, 1999) developed a model of the basement surface of the Paleozoic rocks beneath Yucca Flat and a series of normal faults that create topographic relief on the basement surface. In this study the basement rocks and structure of Yucca Flat are examined in more detail using the basement gravity anomaly derived from the isostatic gravity inversion model of Phelps and others (1999) and high-resolution magnetic data, as part of an effort to gain a better understanding of the Paleozoic rocks beneath Yucca Flat in support of groundwater modeling.

  4. Review of Microbial Responses to Abiotic Environmental Factors in the Context of the Proposed Yucca Mountain Repository

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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

  7. Ground-water recharge in Fortymile Wash near Yucca Mountain, Nevada, 1992--1993

    International Nuclear Information System (INIS)

    Quantification of the ground-water recharge from streamflow in the Fortymile Wash watershed will contribute to regional ground-water studies. Regional ground-water studies are an important component in the studies evaluating the ground-water flow system as a barrier to the potential migration of radionuclides from the potential underground high-level nuclear waste repository. Knowledge gained in understanding the ground-water recharge mechanisms and pathways in the Pah Canyon area, which is 10 km to the northeast of Yucca Mountain, may transfer to Yucca site specific studies. The current data collection network in Fortymile Canyon does not permit quantification of ground-water recharge, however a qualitative understanding of ground-water recharge was developed from these data

  8. Challenges and issues with building a potential railroad to Yucca Mountain

    International Nuclear Information System (INIS)

    On July 23, 2002, the President of the United States signed into law a joint resolution of the United States Congress designating the Yucca Mountain site in Nye County, Nevada, for development as a geologic repository for the disposal of spent nuclear fuel and high-level radioactive waste. If the U.S. Nuclear Regulatory Commission authorizes construction of the repository and receipt and possession of spent nuclear fuel and high-level radioactive at Yucca Mountain, the U.S. Department of Energy (DOE) would be responsible for transporting these materials to the Yucca Mountain repository as part of its obligation under the Nuclear Waste Policy Act. Part of the site recommendation decision included the analysis of a nation-wide shipping campaign to the proposed repository site. The 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'' (February 2002) (Repository EIS) evaluated the potential impacts of the transportation of 70,000 Metric Tons of Heavy Metal spent nuclear fuel and high-level radioactive waste from 77 locations around the nation to the potential repository in Nevada over a 24 year shipping campaign. DOE believes that the Repository EIS provides the environmental impact information necessary to make certain broad transportation-related decisions, namely the choice of a national mode of transportation outside Nevada (mostly rail or mostly legal-weight truck), the choice among alternative transportation modes in Nevada (mostly rail, mostly legal-weight truck, or heavy-haul truck with use of an associated intermodal transfer station), and the choice among alternative rail corridors or heavy-haul truck routes with use of an associated intermodal transfer station in Nevada. In the Repository EIS, DOE identified mostly rail as its preferred mode of transportation, both nationally and in the State of Nevada. In December 2003, based on public

  9. Hydrogeologic studies at Yucca Mountain, Nevada, USA. An interpretation of results for radioactive waste disposal site characterization

    International Nuclear Information System (INIS)

    Of nine potential nuclear-waste repository sites being investigated in the United States, Yucca Mountain is the only one for which disposal above the water table is proposed. The host rock is a fractured, permeable welded tuff more than 300 m beneath the surface. The principal factors contributing to the isolation of waste include: a small recharge flux, estimated to be about 5 mm/yr; free drainage in the host rock and little opportunity for contact of water with the waste; near-neutral water of low ionic and organic content; unsaturated-zone and saturated-zone flowpaths through altered tuffs that are rich in sorptive zeolites and clays; and very deep regional ground-water flow that terminates in a closed basin. Hydraulic testing of the saturated zone has demonstrated that fractures cause the observed high transmissivity, and seepage velocities in major fracture zones may be as high as 0.01 to 0.1 km/yr. Diffusion of radionuclides from water in fractures to that in the porous rock matrix, however, would attenuate their migration and allow sorptive processes to operate if a release from the repository were to occur. Psychrometers, heat-dissipation probes, pressure transducers, and sampling tubes that were recently installed in a 380-m drill hole are still undergoing stabilization. Data from this hole and other planned experiments will allow definition of recharge flux, frequency, and flowpaths for statistical treatment in models

  10. 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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  11. Dialogs by Jerry Szymanski regarding the Yucca Mountain controversy from December, 1990 to March, 1991. Volume 1, Special report No. 9

    International Nuclear Information System (INIS)

    This document contains dialogs from December, 1990 to March, 1991 by Jerry Szymanski regarding the Yucca Mountain controversy. These dialogs involve the dispute about the origin of carbonate deposits at Yucca Mountain; whether pedogenic in origin or a result of episodic upwellings of ground water

  12. On calibration of the UZ site-scale model of Yucca Mountain

    International Nuclear Information System (INIS)

    The 3-D unsaturated-zone site-scale model (model) of Yucca Mountain, under development at the Lawrence Berkeley National Laboratory (LBNL) in cooperation with the U.S. Geological Survey (USGS), has been calibrated against the measured data available for the site. This is an important step in the model development and verification process. The reliability and the accuracy of the model predictions of the moisture, gas, and heat flow and distributions in the mountain depend upon model parameters, imposed boundary conditions, and realistic representations of different-scaled heterogeneous geological features, among other factors. Even though considerable efforts have been made in recent years to investigate hydrologic and rock properties of the Yucca Mountain site, many of the site-specific parameters, such as fracture and fault properties and net infiltration rates, are not well-defined at present. Therefore, as part of the continuous development of the model, a comprehensive calibration study has been conducted to examine and enhance the model capability in predicting the site conditions. This paper presents some of our model calibration results, including incorporation and calibration of (1) saturation and water potential data, (2) gas pressure data, and (3) thermal data. Much more detailed information about the calibration is found in Wu et al

  13. Selected ground-water data for Yucca Mountain Region, southern Nevada and eastern California, through December 22

    International Nuclear Information System (INIS)

    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

  14. Summary of lithologic logging of new and existing boreholes at Yucca Mountain, Nevada, August 1993 to February 1994

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. The Sorption/Desorption Behavior of Uranium in Transport Studies Using Yucca Mountain Alluvium

    International Nuclear Information System (INIS)

    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

  16. Origins of secondary silica within Yucca Mountain, Nye County, southwestern Nevada

    International Nuclear Information System (INIS)

    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

  17. The Sorption/Desorption Behavior of Uranium in Transport Studies Using Yucca Mountain Alluvium

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Status of volcanism studies for the Yucca Mountain Site Characterization Project

    International Nuclear Information System (INIS)

    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

  19. The Yucca Mountain Project prototype air-coring test, U12g tunnel, Nevada test site

    International Nuclear Information System (INIS)

    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

  20. Status of volcanism studies for the Yucca Mountain Site Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Crowe, B.; Perry, F.; Murrell, M.; Poths, J.; Valentine, G.A. [Los Alamos National Lab., NM (United States); Wells, S. [Univ. of California, Riverside, CA (United States); Bowker, L.; Finnegan, K. [Univ. of Nevada, Las Vegas, NV (United States); 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.

  1. Environmental impacts of transportation to the potential repository at Yucca Mountain

    International Nuclear Information System (INIS)

    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. The potential transportation impacts were evaluated 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 5 from the mostly rail scenario. (author)

  2. Data Qualification Report: Precipitation Chloride Data for Use on the Yucca Mountain Project

    International Nuclear Information System (INIS)

    The data covered by this qualification report have been cited in analysis/model reports (AMRs) to support the Site Recommendation in determining the suitability of Yucca Mountain as a repository for high level nuclear waste. Those analyses cited both qualified and unqualified hydrochemical data. This report evaluates unqualified precipitation chloride data based on the pedigree of the data and within the context of supporting analyses on the Yucca Mountain Project (YMP). The following AMRs use the unqualified chloride data considered in this report: (1) AMR S0040, ''Geochemical and Isotopic Constraints on Groundwater Flow Directions, Mixing and Recharge at Yucca Mountain'' (ANL-NBS-HS-000021) (Kwicklis 2000)--an analysis of groundwater recharge rates, flow directions and velocities, and mixing proportions of water from different source areas based on groundwater geochemical and isotopic data. (2) AMR U0085, ''Analysis of Geochemical Data for the Unsaturated Zone'' (ANL-NBS-HS-000017) (Fabryka-Martin 2000)--identifies fluid geochemical parameters for the unsaturated zone, local precipitation, and surface water; discusses the occurrence and origins of fracture minerals; and presents a thermal history of the unsaturated zone. These data are being evaluated for inclusion in technical products to include AMRs and Process Modeling Reports (PMRs) that support the Site Recommendation and that may also be used to support the License Application. A finding that the precipitation chloride data are qualified means that the data are adequate for generalized use and can be appropriately used in a wide variety of applications, so long as consideration is given to limitations on the accuracy, precision and representativeness of the data for an intended use in a technical product

  3. The Yucca Mountain Project prototype air-coring test, U12g tunnel, Nevada test site

    Energy Technology Data Exchange (ETDEWEB)

    Ray, J.M. [Los Alamos National Lab., NM (United States); Newsom, J.C. [Newsom Industries, Citrus Heights, CA (United States)

    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.

  4. Evaluation of habitat restoration needs at Yucca Mountain, Nevada Test Site, Nye County, Nevada

    International Nuclear Information System (INIS)

    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

  5. 1983 biotic studies of Yucca Mountain, Nevada Test Site, Nye County, Nevada

    International Nuclear Information System (INIS)

    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

  6. Geologic character of tuffs in the unsaturated zone at Yucca Mountain, southern Nevada

    International Nuclear Information System (INIS)

    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

  7. Physical processes and effects of magmatism in the Yucca Mountain region

    International Nuclear Information System (INIS)

    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

  8. Crustal structure beneath the Northern Transantarctic Mountains and Wilkes Subglacial Basin: Implications for tectonic origins

    Science.gov (United States)

    Hansen, Samantha E.; Kenyon, Lindsey M.; Graw, Jordan H.; Park, Yongcheol; Nyblade, Andrew A.

    2016-02-01

    The Transantarctic Mountains (TAMs) are the largest noncollisional mountain range on Earth. Their origin, as well as the origin of the Wilkes Subglacial Basin (WSB) along the inland side of the TAMs, has been widely debated, and a key constraint to distinguish between competing models is the underlying crustal structure. Previous investigations have examined this structure but have primarily focused on a small region of the central TAMs near Ross Island, providing little along-strike constraint. In this study, we use data from the new Transantarctic Mountains Northern Network and from five stations operated by the Korea Polar Research Institute to investigate the crustal structure beneath a previously unexplored portion of the TAMs. Using S wave receiver functions and Rayleigh wave phase velocities, crustal thickness and average crustal shear velocity (V>¯s) are resolved within ±4 km and ±0.1 km/s, respectively. The crust thickens from ~20 km near the Ross Sea coast to ~46 km beneath the northern TAMs, which is somewhat thicker than that imaged in previous studies beneath the central TAMs. The crust thins to ~41 km beneath the WSB. V>¯s ranges from ~3.1-3.9 km/s, with slower velocities near the coast. Our findings are consistent with a flexural origin for the TAMs and WSB, where these features result from broad flexure of the East Antarctic lithosphere and uplift along its western edge due to thermal conduction from hotter mantle beneath West Antarctica. Locally, thicker crust may explain the ~1 km of additional topography in the northern TAMs compared to the central TAMs.

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

    International Nuclear Information System (INIS)

    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

  10. Post-closure performance assessment of waste packages for the Yucca Mountain Project

    International Nuclear Information System (INIS)

    This report details a system model of some core features of the performance of waste packages for the permanent disposal of spent nuclear fuel at the Yucca Mountain Site. The model is realized in the prototype computer program PANDORA-1.1. The PANDORA system model links processes leading to possible release of radionuclides from the waste package. The PANDORA submodels are being developed for processes and conditions specific to this potential repository site, notably the comparatively dry location in an arid area and well above the groundwater table, and the rock medium of porous partially welded tuff

  11. Some geochemical considerations for a potential repository site in tuff at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    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

  12. Role of underground testing to determine suitability of Yucca Mountain as a potential repository site

    International Nuclear Information System (INIS)

    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

  13. Transportation cask decontamination and maintenance at the potential Yucca Mountain repository

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

  15. Strategic Basis for License Application Planning for a Potential Yucca Mountain Repository

    International Nuclear Information System (INIS)

    If Yucca Mountain, Nevada is designated as the site for development of a geologic repository for disposal of spent nuclear fuel and high-level radioactive waste, the Department of Energy (DOE) must obtain Nuclear Regulatory Commission (NRC) approval first for repository construction, then for an operating license, and, eventually, for repository closure and decommissioning. The licensing criteria defined in Code of Federal Regulations, Title 10, Part 63 (10 CFR Part 63) establish the basis for these NRC decisions. Submittal of a license application (LA) to the NRC for authorization to construct a repository at the Yucca Mountain site is, at this point, only a potential future action by the DOE. The policy process defined in the Nuclear Waste Policy Act (NWPA), as amended, for recommendation and designation of Yucca Mountain as a repository site makes it difficult to predict whether or when the site might be designated. The DOE may only submit a LA to the NRC if the site designation takes effect. In spite of this uncertainty, the DOE must take prudent and appropriate action now, and over the next several years, to prepare for development and timely submittal of a LA. This is particularly true given the need for the DOE to develop, load, and certify the operation of its electronic information system to provide access to its relevant records as part of the licensing support network (LSN) in compliance with NRC requirements six months prior to LA submittal. The DOE must also develop a LA, which is a substantially different document from those developed to support a Site Recommendation (SR) decision. The LA must satisfy NRC licensing criteria and content requirements, and address the acceptance criteria defined by the NRC in its forthcoming Yucca Mountain Review Plan (YMRP). The content of the LA must be adequate to facilitate NRC acceptance and docketing for review, and the LA and its supporting documents must provide the documented basis for the NR C findings required

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

    International Nuclear Information System (INIS)

    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

  17. Engineered barrier system and waste package design concepts for a potential geologic repository at Yucca Mountain

    International Nuclear Information System (INIS)

    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

  18. Current status of paleohydrologic studies at Yucca Mountain and vicinity, Nevada

    International Nuclear Information System (INIS)

    Recent studies in the vicinity of Yucca Mountain have shown that a water table rise of as much as 100 m may have occurred as recently as the late Pleistocene. New studies have not confirmed the potentially favorable condition of a long-term decline in the elevation of the regional water table. Nonetheless, neither geologic evidence for these past elevations nor hydrologic flow models suggest that rises of the water table in response to climate changes similar to those of the past 2 million years would be sufficient to threaten the potential repository horizon in the future

  19. Discrete fracture modeling-ESF north portal area, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    The purpose of this project is to develop an understanding of fluid flow in partially saturated fractured rock. The Exploratory Studies Facility north portal area (east of Yucca Mountain) was chosen to develop the initial conceptual and flow models. The project will develop statistical parameters from the three-dimensional fracture network and hydraulic parameters that will be used in site scale models. The approach will use geometric fracture models and assess their impact on flow characteristics and parameters. Laboratory and field testing data will be integrated to calibrate the flow models and to determine sensitivities of the system

  20. Site characterization progress report: Yucca Mountain, Nevada, April 1, 1990--September 30, 1990, Number 3

    International Nuclear Information System (INIS)

    In accordance with the requirements of Section 113(b)(3) of the Nuclear Waste Policy Act of 1982 (NWPA), as amended, the US Department of Energy has prepared this report on the progress of site characterization activities at Yucca Mountain, Nevada, for the period April 1 through September 30, 1990. This report is the third of a series of reports that are issued at intervals of approximately six months during site characterization. The report covers a number of new initiatives to improve the effectiveness of the site characterization program and covers continued efforts related to preparatory activities, study plans, and performance assessment. 85 refs., 2 figs., 3 tabs

  1. IHLW conference paper Yucca Mountain Site Characterization Project Environmental Protection Program

    International Nuclear Information System (INIS)

    To ensure the characterization of the Yucca Mountain site is conducted in an environmentally safe and sound manner, the U.S. Department of Energy (DOE) has developed and implemented a comprehensive program that ranges from the acquisition of Federal and State permits to the reclamation of disturbed lands. Among other elements of this program are the following: Identification of relevant environmental regulations, identification of potential environmental impacts, monitoring for potentially significance adverse impacts and mitigation of any impacts that may occur, management of hazardous wastes, waste minimization, and environmental compliance auditing

  2. Evaluation of the American Study 'Viability Assessment of a Repository at Yucca Mountain

    International Nuclear Information System (INIS)

    On behalf of the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU), GRS Cologne studies and evaluates methods used in Performance Assessments of other countries within the framework of long-term safety assessments for geological radioactive waste repositories in order to support the development of this subject in Germany. In this context the following report evaluates the methods of the USA Final Disposal Management used in the U.S.-report ''Viability Assessment of a Repository at Yucca Mountain.'' (orig.)

  3. Site characterization progress report: Yucca Mountain, Nevada, October 1, 1990--March 31, 1991

    International Nuclear Information System (INIS)

    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

  4. Fabrication and closure development of nuclear waste disposal containers for the Yucca Mountain Project: Status report

    International Nuclear Information System (INIS)

    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

  5. Site characterization progress report: Yucca Mountain, Nevada, October 1, 1990--March 31, 1991; Number 4

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  6. Cost-Effective Cementitious Material Compatible with Yucca Mountain Repository Geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Some geochemical considerations for a potential repository site in tuff at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. Changes in water table elevation at Yucca Mountain in response to seismic events

    International Nuclear Information System (INIS)

    Investigation of mechanisms which could significantly alter the elevation of the water table at Yucca Mountain are motivated by the potential impacts such an occurrence would have on the performance of a high-level radioactive waste repository. In particular, we would like to evaluate the possibility of flooding a repository by water-table excursions. Changes in the water table could occur as relatively transient phenomena in response to seismic events by the seismic pumping mechanism. Quantitative evaluation of possible fluctuations of groundwater following earthquakes was undertaken in support of performance assessment calculations including seismicity

  9. Radiological Programs- Ambient Radon at the Yucca Mountain Site (SCPB:NA)

    International Nuclear Information System (INIS)

    This report summarizes the results of the ambient radon monitoring activities conducted by the Radiological/Environmental Field Programs Department of the Civilian Radioactive Waste Management and Operating Contractor (CRWMS M and O), Yucca Mountain Site Characterization Office. Overall, outdoor radon concentrations measured at the Yucca Mountain site were within the range of those reported for other areas in Nevada and the continental United States. Though there was some evidence of trends with time at some monitoring sites, regional atmospheric radon concentrations to date, do not appear to have changed significantly since the inception of site characterization activities. A preliminary dose assessment yielded an estimated annual effective dose equivalent of 134 mrem based on a continuous exposure to the average ambient radon concentration measured at the Yucca Mountain site. Concentrations were measured using two types of systems, passive electret ion chambers (EIC) and continuous radon monitors (CRM). The EICs produced time-averaged radon concentration data and the CRMs were used to study radon fluctuations over time. Between 1991 and 1995, the mean radon concentration at the site, as measured by EICs placed one meter above ground level, was 0.32 ± 0.15 pCi L-1. Radon concentrations varied between monitoring locations and between years. Station NF38, located near the North Portal of the Exploratory Studies Facility (ESF), exhibited the highest overall average radon concentration at 0.55 pCi L-1 (1992 to 1995). Concentrations appear to cycle diurnally, generally peaking in the early morning hours and being lowest in the afternoon. The data also suggested that radon concentrations may fluctuate seasonally. The work accomplished between 1991 and 1995, established radon levels in the general area surrounding Yucca Mountain. It is recommended that further work focus directly on those locations that have the greatest potential for influencing ambient radon levels

  10. Identification of subsurface microorganisms at Yucca Mountain. Quarterly report, July 1, 1994--September 30, 1994

    International Nuclear Information System (INIS)

    Bacteria isolated from ground water samples taken from springs at Yucca Mountain during 1993 were collected and processed. Three bacterial genera commonly found in water (Pseudomonas, Hydrogenophaga, and Alteromonas) were selected for extensive review during this quarter. The presence of bacteria representative of these genera in samples from the 18 springs sampled in Ash Meadows and from 14 springs in Death Valley was reviewed. The species level of identification of the three bacterial genera in water samples from the springs were examined by cluster analysis to see how much variation existed within a given species and also to determine if a species with essentially the same FAME pattern was isolated from several springs

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

    Energy Technology Data Exchange (ETDEWEB)

    Horn, J. M., LLNL

    1998-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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, &apos

  13. Frictional sliding in layered rock model: Preliminary experiments. Yucca Mountain Site Characterization Project

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  15. Oxygen isotopes and trace elements in the Tiva Canyon Tuff, Yucca Mountain and vicinity, Nye County, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    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.

  16. Investigations of hydro-tectonic hazards at the proposed Yucca Mountain high-level nuclear waste repository. Annual report - Nevada

    International Nuclear Information System (INIS)

    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

  17. Review of microbial responses to abiotic environmental factors in the context of the proposed Yucca Mountain repository

    Energy Technology Data Exchange (ETDEWEB)

    Meike, A. [Lawrence Livermore National Lab., Livermore, CA (United States); Stroes-Gascoyne, S

    2000-10-01

    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 behaviour into performance assessment models. One effort was to expand an existing modelling 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 (included in Appendix A) 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. The first part of the report (Chapters 1-3) is a review of general microbial states, phases and requirements for growth, conditions for 'normal growth' and other types of growth, survival strategies and cell death. It contains primarily well-established ideas in microbiology. Microbial capabilities for survival and adaptation to environmental changes are examined because a repository placed at Yucca Mountain would have two effects. First, the natural environment would be perturbed by the excavation and construction of the

  18. Development and testing of techniques to obtain infiltration data for unconsolidated surficial materials, Yucca Mountain area, Nye County, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, Lon L. [Foothill Engineering Consultants, Inc., Denver, CO (United States); Guertal, William R. [USGS, Las Vegas, NV (United States); Flint, Alan L. [USGS, Sacramento, CA (United States)

    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.

  19. Computed distributions of residual shaft drilling and construction water in the exploratory facilities at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    The Yucca Mountain Project is studying the feasibility of constructing a high-level nuclear waste repository at Yucca Mountain in southwest Nevada. One activity of site characterization is the construction of two exploratory shafts. This paper contains the results of engineering analytical calculations of the potential distribution of residual construction water in the exploratory shafts and drifts and numerical calculations of the movement of the residual water and how the movement is affected by drift ventilation. In all cases the increase in rock saturation resulting from the construction water was extremely small. 11 refs., 15 figs., 1 tab

  20. Review of microbial responses to abiotic environmental factors in the context of the proposed Yucca Mountain repository

    International Nuclear Information System (INIS)

    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 behaviour into performance assessment models. One effort was to expand an existing modelling 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 (included in Appendix A) 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. The first part of the report (Chapters 1-3) is a review of general microbial states, phases and requirements for growth, conditions for 'normal growth' and other types of growth, survival strategies and cell death. It contains primarily well-established ideas in microbiology. Microbial capabilities for survival and adaptation to environmental changes are examined because a repository placed at Yucca Mountain would have two effects. First, the natural environment would be perturbed by the excavation and construction of the repository and

  1. Investigations of hydro-tectonic hazards at the proposed Yucca Mountain high-level nuclear waste repository. Annual report - Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Livingston, D.E. [ed.

    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.

  2. Estimation of the limitations for surficial water addition above a potential high level radioactive waste repository at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    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

  3. Faulting in the Yucca Mountain region: Critical review and analyses of tectonic data from the central Basin and Range

    International Nuclear Information System (INIS)

    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

  4. Faulting in the Yucca Mountain region: Critical review and analyses of tectonic data from the central Basin and Range

    Energy Technology Data Exchange (ETDEWEB)

    Ferrill, D.A.; Stirewalt, G.L.; Henderson, D.B.; Stamatakos, J.; Morris, A.P.; Spivey, K.H. [Southwest Research Inst., San Antonio, TX (United States). Center for Nuclear Waste Regulatory Analyses; Wernicke, B.P. [California Inst. of Tech., Pasadena, CA (United States). Div. of Geological and Planetary Sciences

    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.

  5. Summary and evaluation of existing geological and geophysical data near prospective surface facilities in Midway Valley, Yucca Mountain Project, Nye County, Nevada

    International Nuclear Information System (INIS)

    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

  6. Native Americans and Yucca Mountain; A summary report

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, C.S.

    1990-09-01

    This report summarizes data collected between September 1986 and September 1988 relative to Native American concerns involving the potential siting of a high-level nuclear waste repository at Yucca Mountain, Nevada. The data were collected from Western Shoshone and Southern Paiute people upon whose aboriginal lands the repository potentially is to be located. Western Shoshone people involved in the study were those resident or affiliated with reservation communities at Yomba and Duckwater, Nevada, and Death Valley, California. Southern Paiute people were at reservation communities at Moapa and Las Vegas. Additional persons of Western Shoshone and Southern Paiute descent were interviewed at Beatty, Tonopah, Caliente, Pahrump, and Las Vegas, Nevada. The work was part of a larger project of socioeconomic studies for the State of Nevada`s Nuclear Waste Projects office, conducted by Mountain West of Phoenix, Arizona.

  7. Combined analysis of surface reflection imaging and vertical seismic profiling at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. Atmospheric Dispersal and Dispostion of Tephra From a Potential Volcanic Eruption at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Inventory of past DOE land disturbance, Yucca Mountain, Nevada, and estimated general reclamation costs

    International Nuclear Information System (INIS)

    Since 1976, DOE preliminary investigations for a high level nuclear waste repository at Yucca Mountain, Nevada, have caused widespread disturbances of the landscape. This report addresses the areal extent of those disturbances that have accrued up to June 1988, and identifies expected associated reclamation costs. It was first necessary to identify disturbances, next to classify them for reclamation purposes, and, then, to assign general reclamation costs. The purposes of the analysis were: (1) to establish the amount of disturbance that already exists in the area of Yucca Mountain in order to identify alterations of the landscape that comprise the existing baseline conditions; (2) to identify estimated general reclamation costs for repair of the disturbances; (3) to provide information needed to establish disturbance models, and eventually environmental impact models, that can be applied to future DOE activities during Site Characterization and later phases of repository development, if they occur, and (4) to provide indicators of the needs for reclamation of future disturbances created by DOE's Site Characterization program. Disturbances were estimated using measurements from June 1988, large scale color aerial photography. Two reconnaissance site visits were also conducted. The identified disturbance totals by type are displayed in tabular form in the appendices. 84 refs., 2 figs., 9 tabs

  12. Native American interpretation of cultural resources in the area of Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    This report presents the location and interpretation of Native American cultural resources on or near Yucca Mountain, Nevada. This work builds on the archaeological reconnaissance and identifications of cultural resources by the Desert Research Institute (for a summary, see Pippin and Zerga, 1983; Pippin, 1984). Interpretations provided by Native American Indian people are not intended to refute other scientific studies, such as botanical, wildlife, and archaeological studies. Rather, they provide additional hypotheses for future studies, and they provide a more complete cultural understanding of the Yucca Mountain area. Representatives of sixteen American Indian tribes identified the cultural value of these resources as part of a consultation relationship with the US Department of Energy (DOE). This interim report is to be used to review research procedures and findings regarding initial consultation with the sixteen tribes, in-depth interviews with tribal elders, and findings from the first on-site visit with representatives of the sixteen tribes. As additional information is collected, it will be reviewed separately. An annual report will integrate all findings. 44 refs., 58 figs., 2 tabs

  13. Archaeology of Arid Environments Points to Management Options for Yucca Mountain

    International Nuclear Information System (INIS)

    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

  14. Verification of a 1-dimensional model for predicting shallow infiltration at Yucca Mountain

    International Nuclear Information System (INIS)

    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. Modeling studies of gas movement and moisture migration at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Tsang, Y.W.; Pruess, K. [Lawrence Berkeley Lab., CA (United States)

    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.

  16. Quaternary allostratigraphy of surficial deposit map units at Yucca Mountain, Nevada: A progress report

    International Nuclear Information System (INIS)

    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

  17. In situ geochemical measurements in the exploratory shaft at Yucca Mountain

    International Nuclear Information System (INIS)

    Two tests have been proposed by Los Alamos for the Exploratory Shaft at Yucca Mountain to determine, under in situ conditions, the values of geochemical parameters that will be used to assess the performance of a possible nuclear waste repository in the vadose zone. One test will measure diffusion of nonsorbing tracers into the water-filled pores of tuffs at the repository level and below. The diffusivity coefficients derived from the data will be incorporated into transport code calculations that determine the effects of diffusion in retarding the movement of TcO4- and I- under aqueous flow conditions. The second test will measure 36Cl in tuff samples collected as the Exploratory Shaft is mined. The radioactive decay of 36Cl will be used to measure the rate of water movement through the vadose zone over longer times than could be measured by the conventional 14C method. Measurements of 36Cl in soil samples from Yucca Mountain already have helped trace infiltrating precipitation

  18. Yucca Mountain Project bibliography, July--December 1988: An update: Civilian Radioactive Waste Management Program

    International Nuclear Information System (INIS)

    This update contains information on the Yucca Mountain Project that was added to the Energy Data Base during the last six months of 1988. The update also includes a new section which provides information about publications on the Energy Data Base that were not sponsored by the project but have some relevance to it. This section covers the period 1977 to 1988. Prior to August 5, 1988, this project was called the Nevada Nuclear Waste Storage Investigations. The update is categorized by principal project participating organizations, and items are arranged in chronological order. Participant-sponsored subcontractor reports, meeting papers, and journal articles are included with sponsoring organization. Previous information on this project can be found in the Nevada Nuclear Waste Storage Investigations bibliographies: DOE/TIC-3406, which covers the years 1977 to 1985; DOE/OSTI-3406(Suppl.1), which covers 1986 and 1987; and the Yucca Mountain Project Bibliography, DOE/OSTI-3406(Suppl.1)(Add. 1), which covers the first six months of 1988. All entries in these publications are searchable on-line on the NNW data base file which can be accessed through the Integrated Technical Information System (ITIS) of the US Department of Energy

  19. Site characterization progress report: Yucca Mountain, Nevada, October 1, 1993--March 31, 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-10-01

    This report is the tenth 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 spent nuclear fuel and high-level radioactive waste. Also included in this report are descriptions of 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. The Executive Summary is intended to provide a summary of major decisions, activities, accomplishments, and issues of interest during the reporting period. Chapter 1, Introduction, provides background information to assist the reader in understanding the current status of the program. Chapter 2 provides specific detailed discussions of activities conducted during the current reporting period and has two major divisions. Section 2.1, Preparatory Activities, provides information on select preparatory activities necessary to conduct site characterization and design activities. Sections 2.2 through 2.8 provide specific details on studies and activities conducted during the reporting period and follow the original structure of the Department`s 1988 Site Characterization Plan. Chapter 3 contains the current summary schedule, while Chapter 4 provides a description of the program outreach, including activities during the reporting period, in both the international program and public outreach. Chapter 5 presents an epilogue of significant events that occurred after the end of the reporting period.

  20. Mechanical degradation of Emplacement Drifts at Yucca Mountain - A Modeling Case Study. Part I: Nonlithophysal Rock

    International Nuclear Information System (INIS)

    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