WorldWideScience

Sample records for aquifer beneath yucca

  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. Nitrate in aquifers beneath agricultural systems

    Science.gov (United States)

    Burkart, M.R.; Stoner, J.D.; ,

    2007-01-01

    Research from several regions of the world provides spatially anecdotal evidence to hypothesize which hydrologic and agricultural factors contribute to groundwater vulnerability to nitrate contamination. Analysis of nationally consistent measurements from the U.S. Geological Survey's NAWQA program confirms these hypotheses for a substantial range of agricultural systems. Shallow unconfined aquifers are most susceptible to nitrate contamination associated with agricultural systems. Alluvial and other unconsolidated aquifers are the most vulnerable and also shallow carbonate aquifers that provide a substantial but smaller contamination risk. Where any of these aquifers are overlain by permeable soils the risk of contamination is larger. Irrigated systems can compound this vulnerability by increasing leaching facilitated by additional recharge and additional nutrient applications. The system of corn, soybean, and hogs produced significantly larger concentrations of groundwater nitrate than all other agricultural systems because this system imports the largest amount of N-fertilizer per unit production area. Mean nitrate under dairy, poultry, horticulture, and cattle and grains systems were similar. If trends in the relation between increased fertilizer use and groundwater nitrate in the United States are repeated in other regions of the world, Asia may experience increasing problems because of recent increases in fertilizer use. Groundwater monitoring in Western and Eastern Europe as well as Russia over the next decade may provide data to determine if the trend in increased nitrate contamination can be reversed. If the concentrated livestock trend in the United States is global, it may be accompanied by increasing nitrogen contamination in groundwater. Concentrated livestock provide both point sources in the confinement area and intense non-point sources as fields close to facilities are used for manure disposal. Regions where irrigated cropland is expanding, such as

  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. Effect of heterogeneity on radionuclide retardation in the alluvial aquifer near Yucca Mountain, Nevada.

    Science.gov (United States)

    Painter, S; Cvetkovic, V; Turner, D R

    2001-01-01

    The U.S. Department of Energy is currently studying Yucca Mountain, Nevada, as a potential site for a geological high-level waste repository. In the current conceptual models of radionuclide transport at Yucca Mountain, part of the transport path to pumping locations would be through an alluvial aquifer. Interactions with minerals in the alluvium are expected to retard the downstream migration of radionuclides, thereby delaying arrival times and reducing ground water concentrations. We evaluate the effectiveness of the alluvial aquifer as a transport barrier using the stochastic Lagrangian framework. A transport model is developed to account for physical and chemical heterogeneities and rate-limited mass transfer between mobile and immobile zones. The latter process is caused by small-scale heterogeneity and is thought to control the macroscopic-scale retardation in some field experiments. A geostatistical model for the spatially varying sorption parameters is developed from a site-specific database created from hydrochemical measurements and a calibrated modeling approach (Turner and Pabalan 1999). Transport of neptunium is considered as an example. The results are sensitive to the rate of transfer between mobile and immobile zones, and to spatial variability in the hydraulic conductivity. Chemical heterogeneity has only a small effect, as does correlation between hydraulic conductivity and the neptunium distribution coefficient. These results illustrate how general sensitivities can be explored with modest effort within the Lagrangian framework. Such studies complement and guide the application of more detailed numerical simulations.

  5. Advective heat transport in the upper carbonate aquifer beneath Winnipeg, Manitoba

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, G.A.G.; Woodbury, A.D. [Manitoba Univ., Winnipeg, MB (Canada). Dept. of Civil Engineering

    2003-07-01

    Air conditioning and industrial cooling in Winnipeg, Manitoba requires large volumes of groundwater, with the bulk of this water pumped from the Upper Carbonate Aquifer. Pumping takes place at the erosional surface of several dipping Paleozoic carbonate units beneath the city. To prevent excessive drawdown, wastewater from these processes is reinjected into the aquifer. Heat loading from the surface, combined with this practice, leads to the creation of areas of elevated temperature within the Upper Carbonate Aquifer. An industrial area located in eastern Winnipeg is the site of the largest of these anomalies, where the aquifer's permeability is enhanced by the presence of conduits and discrete fractures. The use of numerical modeling showed that the greatest temperature anomalies occur where there are very high permeabilities, especially in the form of conduits and discrete fractures. Groundwater velocities are increased by these factors, and could result in the creation of plumes of heated water. Plumes of heated water are less likely to occur where the aquifer is thicker and conduits are absent, due to advective heat transport becoming focused between the injection well and the production well in lower permeability situations. These areas also correspond to the areas of decreased transmissivity in several parts of the Upper Carbonate Aquifer, and may not be capable of producing the required volumes of groundwater for thermal applications. Taking into account these permeability features in planning and design of non-consumptive groundwater systems in the Upper Carbonate Aquifer helps to minimize both drawdown and changes in aquifer temperature. 8 refs., 2 figs.

  6. Nature and extent of lava-flow aquifers beneath Pahute Mesa, Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Prothro, L.B.; Drellack, S.L. Jr.

    1997-09-01

    Work is currently underway within the Underground Test Area subproject of the US Department of Energy/Nevada Operations Office Environmental Restoration Program to develop corrective action plans in support of the overall corrective action strategy for the Nevada Test Site as established in the Federal Facility Agreement and Consent Order (FFACO, 1996). A closure plan is currently being developed for Pahute Mesa, which has been identified in the FFACO as consisting of the Western and Central Pahute Mesa Corrective Action Units. Part of this effort requires that hydrogeologic data be compiled for inclusion in a regional model that will be used to predict a contaminant boundary for these Corrective Action Units. Hydrogeologic maps have been prepared for use in the model to define the nature and extent of aquifers and confining units that might influence the flow of contaminated groundwater from underground nuclear tests conducted at Pahute Mesa. Much of the groundwater flow beneath Pahute Mesa occurs within lava-flow aquifers. An understanding of the distribution and hydraulic character of these important hydrogeologic units is necessary to accurately model groundwater flow beneath Pahute Mesa. This report summarizes the results of a study by Bechtel Nevada geologists to better define the hydrogeology of lava-flow aquifers at Pahute Mesa. The purpose of this study was twofold: (1) aid in the development of the hydrostratigraphic framework for Pahute Mesa, and (2) provide information on the distribution and hydraulic character of lava-flow aquifers beneath Pahute Mesa for more accurate computer modeling of the Western and Central Pahute Mesa Corrective Action Units.

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

    Energy Technology Data Exchange (ETDEWEB)

    Inyo County

    2006-07-26

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

  8. Approaches to Quantify Potential Contaminant Transport in the Lower Carbonate Aquifer from Underground Nuclear Testing at Yucca Flat, Nevada National Security Site, Nye County, Nevada - 12434

    International Nuclear Information System (INIS)

    Quantitative modeling of the potential for contaminant transport from sources associated with underground nuclear testing at Yucca Flat is an important part of the strategy to develop closure plans for the residual contamination. At Yucca Flat, the most significant groundwater resource that could potentially be impacted is the Lower Carbonate Aquifer (LCA), a regionally extensive aquifer that supplies a significant portion of the water demand at the Nevada National Security Site, formerly the Nevada Test Site. Developing and testing reasonable models of groundwater flow in this aquifer is an important precursor to performing subsequent contaminant transport modeling used to forecast contaminant boundaries at Yucca Flat that are used to identify potential use restriction and regulatory boundaries. A model of groundwater flow in the LCA at Yucca Flat has been developed. Uncertainty in this model, as well as other transport and source uncertainties, is being evaluated as part of the Underground Testing Area closure process. Several alternative flow models of the LCA in the Yucca Flat/Climax Mine CAU have been developed. These flow models are used in conjunction with contaminant transport models and source term models and models of contaminant transport from underground nuclear tests conducted in the overlying unsaturated and saturated alluvial and volcanic tuff rocks to evaluate possible contaminant migration in the LCA for the next 1,000 years. Assuming the flow and transport models are found adequate by NNSA/NSO and NDEP, the models will undergo a peer review. If the model is approved by NNSA/NSO and NDEP, it will be used to identify use restriction and regulatory boundaries at the start of the Corrective Action Decision Document Corrective Action Plan (CADD/CAP) phase of the Corrective Action Strategy. These initial boundaries may be revised at the time of the Closure Report phase of the Corrective Action Strategy. (authors)

  9. Groundwater salinization mechanism of aquifers beneath Ho Chi Minh City area (Viet Nam)

    International Nuclear Information System (INIS)

    Water supplying for domestic and product activities in Hochiminh City is being taken from two both sources: surface water and groundwater. Environmental isotopes technique is emphasized to determine the salinisation mechanism of groundwater. The objectives studied are groundwater of two aquifers mainly being exploited in Hochiminh City area. Based on the national water monitoring wells existing in the studied area and the hydrogeological setting a network of 70 sampling points for both two aquifers was set up. Water samples were collected two times (in rainy season of 2001 and in the end of dry season of 2002). All collected samples were analyzed for hydrochemical and stable isotopes. 30 of them were analyzed for tritium and 15 of them were done for 14C. Analyzing hydrochemical results of collected samples show that the quality of groundwater varies from fresh to saline, soft to very hard and high iron contents in some regions. The analyses of cations and anions by Piper Trilinear Diagram show that in aquifers where saline groundwater distributed the cations are mainly sodium, calcium, and magnesium type while the anions are mainly chloride and sulfate type but in the part where fresh groundwater the cations are mainly sodium, calcium, and type while the anions are mainly bicarbonate, carbonate and nitrate type. According to TDS values the distribution of fresh and saline groundwater in studied aquifers is mapped and fresh-saline groundwater boundaries in 1990 and 2000 is also demonstrated. The distribution of groundwater samples collected along the GMWL show that groundwater in this area is recharged directly by rainfall and surface water. High tritium contents and 14C relative radioactivity of groundwater in the area also support this process. Delta values of 18O and Chloride contents plot show that it exists two main salinisation mechanism. The first one is the leaching process and the second one is mixing with seawater process and both these mechanisms are

  10. REACTIVE MULTIPHASE BEHAVIOR OF CO2 IN SALINE AQUIFERS BENEATH THE COLORADO PLATEAU

    Energy Technology Data Exchange (ETDEWEB)

    R.G. Allis; J. Moore; S. White

    2003-01-30

    Gas reservoirs developed within the Colorado Plateau and Southern Rocky Mountains region represent unique natural laboratories for studying the conditions that control long-term storage of CO{sub 2}. Under appropriate conditions, the trapping of CO{sub 2} in mineral phases could equal or exceed the amount of CO{sub 2} sequestered in the pore fluids in deep aquifers. Core samples from the Springerville-St. Johns CO{sub 2} field has allowed investigation of naturally occurring mineral reactions. The presence of travertine deposits over the field provide evidence of the leakage of CO{sub 2} to the atmosphere and justify further study. During reporting period covered here (January 1 to March 30, 2003), the main achievements were: (1) Preparation of three papers to be presented at the Second Annual Conference on Carbon Sequestion (May 5-8, Alexandria, Virginia) and (2) Preparation of two papers for submission to a special volume of Chemical Geology on CO{sub 2} Sequestration.

  11. Aquifers

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This map layer contains the shallowest principal aquifers of the conterminous United States, Hawaii, Puerto Rico, and the U.S. Virgin Islands, portrayed as...

  12. Death Valley Lower Carbonate Aquifer Monitoring Program Wells Down Gradient of the Proposed Yucca Mountain Nuclear Waste Repository, U. S. Department of Energy Grant DE-RW0000233 2010 Project Report, prepared by The Hydrodynamics Group, LLC for Inyo County Yucca Mountain Repository Assessment Office

    Energy Technology Data Exchange (ETDEWEB)

    King, Michael J; Bredehoeft, John D., Dr.

    2010-09-03

    Inyo County completed the first year of the U.S. Department of Energy Grant Agreement No. DE-RW0000233. This report presents the results of research conducted within this Grant agreement in the context of Inyo County's Yucca Mountain oversight program goals and objectives. The Hydrodynamics Group, LLC prepared this report for Inyo County Yucca Mountain Repository Assessment Office. The overall goal of Inyo County's Yucca Mountain research program is the evaluation of far-field issues related to potential transport, by ground water, of radionuclide into Inyo County, including Death Valley, and the evaluation of a connection between the Lower Carbonate Aquifer (LCA) and the biosphere. Data collected within the Grant is included in interpretive illustrations and discussions of the results of our analysis. The centeral elements of this Grant prgoram was the drilling of exploratory wells, geophysical surveys, geological mapping of the Southern Funeral Mountain Range. The cullimination of this research was 1) a numerical ground water model of the Southern Funeral Mountain Range demonstrating the potential of a hydraulic connection between the LCA and the major springs in the Furnace Creek area of Death Valley, and 2) a numerical ground water model of the Amargosa Valley to evaluate the potential for radionuclide transport from Yucca Mountain to Inyo County, California. The report provides a description of research and activities performed by The Hydrodynamics Group, LLC on behalf of Inyo County, and copies of key work products in attachments to this report.

  13. 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

  14. Sub-crop geologic map of pre-Tertiary rocks in the Yucca Flat and northern Frenchman Flat areas, Nevada Test Site, southern Nevada

    International Nuclear Information System (INIS)

    for ground water flow through pre-Tertiary rocks beneath the Yucca Flat and northern Frenchman Flat areas, and has consequences for ground water modeling and model validation. Our data indicate that the Mississippian Chainman Shale is not laterally extensive confining unit in the western part of the basin because it is folded back onto itself by the convergent structures of the Belted Range and CP thrust systems. Early and Middle Paleozoic limestone and dolomite are present beneath most of both basins and, regardless of structural complications, are interpreted to form a laterally continuous and extensive carbonate aquifer. Structural culmination that marks the French Peak accommodation zone along the topographic divide between the two basins provides a lateral pathway through highly fractured rock between the volcanic aquifers of Yucca Flat and the regional carbonate aquifer. This pathway may accelerate the migration of ground-water contaminants introduced by underground nuclear testing toward discharge areas beyond the Nevada Test Site boundaries. Predictive three-dimensional models of hydrostratigraphic units and ground-water flow in the pre-Tertiary rocks of subsurface Yucca Flat are likely to be unrealistic due to the extreme structural complexities. The interpretation of hydrologic and geochemical data obtained from monitoring wells will be difficult to extrapolate through the flow system until more is known about the continuity of hydrostratigraphic units. 1 plate

  15. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Area where upper confining unit is thin or absent beneath the surficial aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  16. 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

  17. 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.

  18. Hydrostratigraphy of the Snake River Plain aquifer beneath the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory: A preliminary report

    International Nuclear Information System (INIS)

    Geophysical logs for 6 wells which penetrate the Snake River Plain aquifer at the Radioactive Waste Management Complex (RWMC) were analyzed for preliminary information on the hydrostratigraphy. Using stratigraphic correlation of flow groups worked out by Anderson and Lewis (1989), and by Anderson, as well as gamma signatures of flows within these flow groups, correlation of individual flows is attempted. Within these flows, probable permeable zones, suggested by density and caliper logs, are identified, and zones of hydraulic connection are tentatively correlated. In order to understand the response of density and neutron logs in basalt, the geological characteristics are quantified for the 150-ft section of the well C1A core, from depth 550 to 710 ft. 9 refs., 4 figs

  19. The Hydrogeologic Character of the Lower Tuff Confining Unit and the Oak Springs Butte Confining Unit in the Tuff Pile Area of Central Yucca Flat

    Energy Technology Data Exchange (ETDEWEB)

    Drellack, Jr., Sigmund L.; Prothro, Lance B.; Gonzales, Jose L.; Mercadante, Jennifer M.

    2010-07-30

    The lower tuff confining unit (LTCU) in the Yucca Flat Corrective Action Unit (CAU) consists of a monotonous sequence of pervasively zeolitized volcanic tuff (i.e., mostly bedded with lesser nonwelded to poorly welded tuff; not fractured) (Bechtel Nevada, 2006). The LTCU is an important confining unit beneath Yucca Flat because it separates the alluvial and volcanic aquifers, where many underground nuclear tests were conducted, from the regional lower carbonate aquifer. Recent sub-CAU-scale modeling by Los Alamos National Laboratory in the Tuff Pile area of Yucca Flat (Boryta, et al., in review) includes postulated low-porosity, high-permeability zones (i.e., fractured welded-tuff aquifers) within the LTCU. This scenario indicates that such postulated low-porosity, high-permeability zones could provide fast-path lateral conduits to faults, and eventually to the lower carbonate aquifer. A fractured and faulted lower carbonate aquifer is postulated to provide a flow path(s) for underground test-derived contaminants to potential offsite receptors. The ramifications of such a scenario are obvious for groundwater flow and contaminant migration beneath Yucca Flat. This paper describes the reasoning for not including postulated low-porosity, high-permeability zones within the LTCU in the Tuff Pile area or within the LTCU in the Yucca Flat CAU-scale model. Both observational and analytical data clearly indicate that the LTCU in the Tuff Pile area consists of pervasively zeolitic, nonwelded to poorly welded tuffs that are classified as tuff confining units (i.e., high-porosity, low-permeability). The position regarding the LTCU in the Tuff Pile area is summarized as follows: • The LTCU in the Tuff Pile area consists of a monotonous sequence of predominantly zeolitic nonwelded to poorly welded tuffs, and thus is accurately characterized hydrogeologically as a tuff confining unit (aquitard) in the Yucca Flat-Climax Mine hydrostratigraphic framework model (Bechtel Nevada

  20. 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

  1. 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

  2. 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

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. 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

  8. 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.

  9. 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

  10. Alluvial Aquifer

    Data.gov (United States)

    Kansas Data Access and Support Center — This coverage shows the extents of the alluvial aquifers in Kansas. The alluvial aquifers consist of unconsolidated Quaternary alluvium and contiguous terrace...

  11. Interconnectivity between the Superficial Aquifer and the Deep Confined Aquifers of the Gnangara Mound, Western Australia

    International Nuclear Information System (INIS)

    Perth groundwater resources are obtained from three major aquifers that occur beneath the Perth metropolitan area: the Superficial aquifer, Leederville aquifer and Yarragadee aquifer. Each aquifer has a unique seasonal water level pattern controlled by soils, geomorphology and geology. Land use is mainly responsible for variations in recharge; however, the hydraulic properties control aquifer response and water level pattern to a greater degree. Groundwater in the three aquifers is generally of very good quality except in localised areas. Salinity increases with depth and in direction of groundwater flow in the three aquifers. The best water quality is in the Superficial aquifer in the Wanneroo well field area. The geochemistry and stable isotope signatures from the three major aquifers revealed distinct water types that suggest very little hydraulic connection or mixing of waters between these aquifers at the present abstraction and recharge regimes. The results also show that the Leederville and Yarragadee aquifers were recharged during earlier cooler times while the Superficial aquifer is being recharged at present

  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. 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.

  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. Modeling groundwater levels on the Calera Aquifer Region in Central Mexico using ModFLow.

    Science.gov (United States)

    A conceptual model for the Calera Aquifer has been created to represent the aquifer system beneath the Calera Aquifer Region (CAR) in the State of Zacatecas, Mexico. The CAR area was uniformly partitioned into a 500 X 500 m grid generating a high resolution model that represented the natural boundar...

  17. 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

  18. Geology at Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-05-01

    Both advocates and critics disagree on the significance and interpretation of critical geological features which bear on the safety and suitability of Yucca Mountain as a site for the construction of a high-level radioactive waste repository. Critics believe that there is sufficient geological evidence to rule the site unsuitable for further investigation. Some advocates claim that there is insufficient data and that investigations are incomplete, while others claim that the site is free of major obstacles. We have expanded our efforts to include both the critical evaluations of existing geological and geochemical data and the collection of field data and samples for the purpose of preparing scientific papers for submittal to journals. Summaries of the critical reviews are presented in this paper.

  19. A Black Hills-Madison Aquifer origin for Dakota Aquifer groundwater in northeastern Nebraska.

    Science.gov (United States)

    Stotler, Randy; Harvey, F Edwin; Gosselin, David C

    2010-01-01

    Previous studies of the Dakota Aquifer in South Dakota attributed elevated groundwater sulfate concentrations to Madison Aquifer recharge in the Black Hills with subsequent chemical evolution prior to upward migration into the Dakota Aquifer. This study examines the plausibility of a Madison Aquifer origin for groundwater in northeastern Nebraska. Dakota Aquifer water samples were collected for major ion chemistry and isotopic analysis ((18)O, (2)H, (3)H, (14)C, (13)C, (34)S, (18)O-SO(4), (87)Sr, (37)Cl). Results show that groundwater beneath the eastern, unconfined portion of the study area is distinctly different from groundwater sampled beneath the western, confined portion. In the east, groundwater is calcium-bicarbonate type, with delta(18)O values (-9.6 per thousand to -12.4 per thousand) similar to local, modern precipitation (-7.4 per thousand to -10 per thousand), and tritium values reflecting modern recharge. In the west, groundwater is calcium-sulfate type, having depleted delta(18)O values (-16 per thousand to -18 per thousand) relative to local, modern precipitation, and (14)C ages 32,000 to more than 47,000 years before present. Sulfate, delta(18)O, delta(2)H, delta(34)S, and delta(18)O-SO(4) concentrations are similar to those found in Madison Aquifer groundwater in South Dakota. Thus, it is proposed that Madison Aquifer source water is also present within the Dakota Aquifer beneath northeastern Nebraska. A simple Darcy equation estimate of groundwater velocities and travel times using reported physical parameters from the Madison and Dakota Aquifers suggests such a migration is plausible. However, discrepancies between (14)C and Darcy age estimates indicate that (14)C ages may not accurately reflect aquifer residence time, due to mixtures of varying aged water.

  20. 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

  1. Mississippian aquifers

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the Mississippian aquifers in the states of Pennsylvania, Ohio, West Virginia, Virginia, Kentucky, Tennessee, Alabama,...

  2. Ozark Aquifer

    Data.gov (United States)

    Kansas Data Access and Support Center — These digital maps contain information on the altitude of the base and top, the extent, and the potentiometric surface of the Ozark aquifer in Kansas. The Ozark...

  3. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, Jeanette

    2007-12-11

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

  5. Deep Resistivity Structure of Yucca Flat, Nevada Test Site, Nevada.

    Energy Technology Data Exchange (ETDEWEB)

    Theodore H. Asch, Brian D. Rodriguez; Jay A. Sampson; Erin L. Wallin; and Jackie M. Williams.

    2006-09-18

    The Department of Energy (DOE) and the National Nuclear Security Administration (NNSA) at their Nevada Site Office are addressing groundwater contamination resulting from historical underground nuclear testing through the Environmental Management program and, in particular, the Underground Test Area project. One issue of concern is the nature of the somewhat poorly constrained pre Tertiary geology and its effects on ground-water flow in the area adjacent to a nuclear test. Ground water modelers would like to know more about the hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Yucca Flat Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey, supported by the DOE and NNSA-NSO, collected and processed data from 51 magnetotelluric (MT) and audio-magnetotelluric (AMT) stations at the Nevada Test Site in and near Yucca Flat to assist in characterizing the pre-Tertiary geology in that area. The primary purpose was to refine the character, thickness, and lateral extent of pre Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (late Devonian – Mississippian-age siliciclastic rocks assigned to the Eleana Formation and Chainman Shale) in the Yucca Flat area. The MT and AMT data have been released in separate USGS Open File Reports. The Nevada Test Site magnetotelluric data interpretation presented in this report includes the results of detailed two-dimensional (2 D) resistivity modeling for each profile (including alternative interpretations) and gross inferences on the three dimensional (3 D) character of the geology beneath each station. The character, thickness, and lateral extent of the Chainman Shale and Eleana Formation that comprise the Upper Clastic Confining Unit are generally well determined in the upper 5 km. Inferences can be made regarding the presence of the Lower Clastic Confining Unit at depths below 5 km. Large

  6. Determinism beneath Quantum Mechanics

    CERN Document Server

    Hooft, G

    2002-01-01

    Contrary to common belief, it is not difficult to construct deterministic models where stochastic behavior is correctly described by quantum mechanical amplitudes, in precise accordance with the Copenhagen-Bohr-Bohm doctrine. What is difficult however is to obtain a Hamiltonian that is bounded from below, and whose ground state is a vacuum that exhibits complicated vacuum fluctuations, as in the real world. Beneath Quantum Mechanics, there may be a deterministic theory with (local) information loss. This may lead to a sufficiently complex vacuum state, and to an apparent non-locality in the relation between the deterministic ("ontological") states and the quantum states, of the kind needed to explain away the Bell inequalities. Theories of this kind would not only be appealing from a philosophical point of view, but may also be essential for understanding causality at Planckian distance scales.

  7. 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.

  8. 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

  9. Conceptualization of the predevelopment groundwater flow system and transient water-level responses in Yucca Flat, Nevada National Security Site, Nevada

    Science.gov (United States)

    Fenelon, Joseph M.; Sweetkind, Donald S.; Elliott, Peggy E.; Laczniak, Randell J.

    2012-01-01

    Contaminants introduced into the subsurface of Yucca Flat, Nevada National Security Site, by underground nuclear testing are of concern to the U.S. Department of Energy and regulators responsible for protecting human health and safety. The potential for contaminant movement away from the underground test areas and into the accessible environment is greatest by groundwater transport. The primary hydrologic control on this transport is evaluated and examined through a set of contour maps developed to represent the hydraulic-head distribution within the two major aquifer systems underlying the area. Aquifers and confining units within these systems were identified and their extents delineated by merging and analyzing hydrostratigraphic framework models developed by other investigators from existing geologic information. Maps of the hydraulic-head distributions in the major aquifer systems were developed from a detailed evaluation and assessment of available water-level measurements. The maps, in conjunction with regional and detailed hydrogeologic cross sections, were used to conceptualize flow within and between aquifer systems. Aquifers and confining units are mapped and discussed in general terms as being one of two aquifer systems: alluvial-volcanic or carbonate. The carbonate aquifers are subdivided and mapped as independent regional and local aquifers, based on the continuity of their component rock. Groundwater flow directions, approximated from potentiometric contours, are indicated on the maps and sections and discussed for the alluvial-volcanic and regional carbonate aquifers. Flow in the alluvial-volcanic aquifer generally is constrained by the bounding volcanic confining unit, whereas flow in the regional carbonate aquifer is constrained by the siliceous confining unit. Hydraulic heads in the alluvial-volcanic aquifer typically range from 2,400 to 2,530 feet and commonly are elevated about 20-100 feet above heads in the underlying regional carbonate

  10. 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

  11. 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

  12. 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.

  13. A refined characterization of the alluvial geology of yucca flat and its effect on bulk hydraulic conductivity

    Science.gov (United States)

    Phelps, G.A.; Halford, K.J.

    2011-01-01

    In Yucca Flat, on the Nevada National Security Site in southern Nevada, the migration of radionuclides from tests located in the alluvial deposits into the Paleozoic carbonate aquifer involves passage through a thick, heterogeneous section of late Tertiary and Quaternary alluvial sediments. An understanding of the lateral and vertical changes in the material properties of the alluvial sediments will aid in the further development of the hydrogeologic framework and the delineation of hydrostratigraphic units and hydraulic properties required for simulating groundwater flow in the Yucca Flat area. Previously published geologic models for the alluvial sediments within Yucca Flat are based on extensive examination and categorization of drill-hole data, combined with a simple, data-driven interpolation scheme. The U.S. Geological Survey, in collaboration with Stanford University, is researching improvements to the modeling of the alluvial section, incorporating prior knowledge of geologic structure into the interpolation method and estimating the uncertainty of the modeled hydrogeologic units.

  14. Isotopic evidence of complex ground-water flow at Yucca mountain, Nevada, USA

    Science.gov (United States)

    Peterman, Zell E.; Stuckless, John S.

    1993-01-01

    Strontium isotopes (expressed as per mill deviation from mean sea water, ??87Sr) reflect interaction between ground water and the aquifer through which it is flowing. In the Cenozoic aquifer of the Yucca Mountain region, ??87Sr values increase from north to south downgradient in the flow system. The largest ??87Sr values occur in the Amargosa Desert where ground water probably encounters alluvial basin fill derived from Precambrian rocks in the Funeral Range. Similarly, large ??87Sr values for ground water in the Paleozoic aquifer at the western end of the Spring Mountains also probably reflect an encounter with Precambrian rocks. In several wells into the volcanic rocks, apparent isotopic disequilibrium between ground water and the producing units suggests that the ground water probably integrates over a substantial part of the saturated section in attaining its strontium isotope signature.

  15. Radionuclide Transport in Tuff and Carbonate Fractures from Yucca Flat, Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Zavarin, M; Johnson, M R; Roberts, S K; Pletcher, R; Rose, T P; Kersting, A B; Eaton, G; Hu, Q; Ramon, E; Walensky, J; Zhao, P

    2006-02-01

    In the Yucca Flat basin of the Nevada Test Site (NTS), 747 shaft and tunnel nuclear detonations were conducted primarily within the tuff confining unit (TCU) or the overlying alluvium. The TCU in the Yucca Flat basin is hypothesized to reduce radionuclide migration to the regional carbonate aquifer (lower carbonate aquifer) due to its wide-spread aerial extent and chemical reactivity. However, shortcuts through the TCU by way of fractures may provide a migration path for radionuclides to the lower carbonate aquifer (LCA). It is, therefore, imperative to understand how radionuclides migrate or are retarded in TCU fractures. Furthermore, understanding the migration behavior of radionuclides once they reach the fractured LCA is important for predicting contaminant transport within the regional aquifer. The work presented in this report includes: (1) information on the radionuclide reactive transport through Yucca Flat TCU fractures (likely to be the primary conduit to the LCA), (2) information on the reactive transport of radionuclides through LCA fractures and (3) data needed to calibrate the fracture flow conceptualization of predictive models. The predictive models are used to define the extent of contamination for the Underground Test Area (UGTA) project. Because of the complex nature of reactive transport in fractures, a stepwise approach to identifying mechanisms controlling radionuclide transport was used. In the first set of TCU experiments, radionuclide transport through simple synthetic parallel-plate fractured tuff cores was examined. In the second, naturally fractured TCU cores were used. For the fractured LCA experiments, both parallel-plate and rough-walled fracture transport experiments were conducted to evaluate how fracture topography affects radionuclide transport. Tuff cores were prepared from archived UE-7az and UE-7ba core obtained from the USGS core library, Mercury, Nevada. Carbonate cores were prepared from archived ER-6-1 core, also obtained

  16. Geologic Characterization of Young Alluvial Basin-Fill Deposits from Drill Hole Data in Yucca Flat, Nye County, Nevada

    Science.gov (United States)

    Sweetkind, Donald S.; Drake II, Ronald M.

    2007-01-01

    Yucca Flat is a topographic and structural basin in the northeastern part of the Nevada Test Site (NTS) in Nye County, Nevada, that has been the site of numerous underground nuclear tests; many of these tests occurred within the young alluvial basin-fill deposits. The migration of radionuclides to the Paleozoic carbonate aquifer involves passage through this thick, heterogeneous section of Tertiary and Quaternary rock. An understanding of the lateral and vertical changes in the material properties of young alluvial basin-fill deposits will aid in the further development of the hydrogeologic framework and the delineation of hydrostratigraphic units and hydraulic properties required for simulating ground-water flow in the Yucca Flat area. This report by the U.S. Geological Survey, in cooperation with the U.S. Department of Energy, presents data and interpretation regarding the three-dimensional variability of the shallow alluvial aquifers in areas of testing at Yucca Flat, data that are potentially useful in the understanding of the subsurface flow system. This report includes a summary and interpretation of alluvial basin-fill stratigraphy in the Yucca Flat area based on drill hole data from 285 selected drill holes. Spatial variations in lithology and grain size of the Neogene basin-fill sediments can be established when data from numerous drill holes are considered together. Lithologic variations are related to different depositional environments within the basin including alluvial fan, channel, basin axis, and playa deposits.

  17. 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

  18. Modeling Approach/Strategy for Corrective Action Unit 97, Yucca Flat and Climax Mine , Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Janet Willie

    2003-08-01

    The objectives of the UGTA corrective action strategy are to predict the location of the contaminant boundary for each CAU, develop and implement a corrective action, and close each CAU. The process for achieving this strategy includes modeling to define the maximum extent of contaminant transport within a specified time frame. Modeling is a method of forecasting how the hydrogeologic system, including the underground test cavities, will behave over time with the goal of assessing the migration of radionuclides away from the cavities and chimneys. Use of flow and transport models to achieve the objectives of the corrective action strategy is specified in the FFACO. In the Yucca Flat/Climax Mine system, radionuclide migration will be governed by releases from the cavities and chimneys, and transport in alluvial aquifers, fractured and partially fractured volcanic rock aquifers and aquitards, the carbonate aquifers, and in intrusive units. Additional complexity is associated with multiple faults in Yucca Flat and the need to consider reactive transport mechanisms that both reduce and enhance the mobility of radionuclides. A summary of the data and information that form the technical basis for the model is provided in this document.

  19. 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

  20. Analysis of pumping-induced unsaturated regions beneath a perennial river

    Science.gov (United States)

    Su, G.W.; Jasperse, J.; Seymour, D.; Constante, J.; Zhou, Q.

    2007-01-01

    The presence of an unsaturated region beneath a streambed during groundwater pumping near streams can reduce the pumping capacity, change flow paths, and alter the types of biological transformations in the streambed sediments. A three-dimensional, multiphase flow model of two horizontal collector wells along the Russian River near Forestville, California, was developed to investigate the impact of varying the ratio of the aquifer to streambed permeability on (1) the formation of an unsaturated region beneath the stream, (2) the pumping capacity, (3) stream water fluxes through the streambed, and (4) stream water traveltimes to the collector wells. The aquifer to streambed permeability ratio at which the unsaturated region was initially observed ranged from 10 to 100. The size of the unsaturated region beneath the streambed increased as the aquifer to streambed permeability ratio increased. The simulations also indicated that for a particular aquifer permeability, decreasing the streambed permeability by only a factor of 2-3 from the permeability where desaturation initially occurred resulted in reducing the pumping capacity. In some cases, the stream water fluxes increased as the streambed permeability decreased. However, the stream water residence times increased and the fraction of stream water that reached that the wells decreased as the streambed permeability decreased, indicating that a higher streambed flux does not necessarily correlate to greater recharge of stream water around the wells. Copyright 2007 by the American Geophysical Union.

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

    Energy Technology Data Exchange (ETDEWEB)

    Montazer, P.; Wilson, W.E.

    1985-12-31

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

  2. Chemical transport beneath a uranium mill tailings pile, Riverton, Wyoming

    International Nuclear Information System (INIS)

    A detailed geochemical study at the Riverton site was undertaken in order to define the nature of chemical transport between an inactive tailings pile and the relationship between the underlying shallow groundwater system. Isotopic measurements of oxygen, deuterium, and tritium showed that although both the shallow alluvial aquifer and a deeper aquifer in the Wind River Formation were derived from a similar source, the nearby river, recharge from the tailings pile is occurring only in the shallow alluvium. 34S/32S ratios are used as a conservative tracer in defining zones of tailings water contamination. Offsite, drilling has revealed the existence of a chemical plume in which calcium and sulfate concentrations are an order of magnitude or more above background. The plume is also characterized by high dissolved molybdenum concentrations. Pore waters in the tailings exhibit extremely high concentrations of Al, Fe and SO4 and low pH. The dissolution of calcite occurs in the alluvium beneath the pile which is characterized by high partial pressures of CO/sub 2(g)/ in the tailings while serving to neutralize pH. The groundwater, however remains saturated with CaCO3, suggesting that a buffering capacity is active. Beneath and downgradient from the tailings, the groundwater becomes saturated with gypsum. The chemical speciation code, PHREEQE, was used to model mixing reactions, assuming a hydrologically static system. Reaction path simulations were fit to observed trends of pH that were depressed in the contaminated groundwater. The simulations estimate one percent mixing of tailings-pore water with groundwater from the shallow alluvial aquifer

  3. 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

  4. 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

  5. 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.

  6. 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

  7. Ground-water flow and quality beneath sewage-sludge lagoons, and a comparison with the ground-water quality beneath a sludge-amended landfill, Marion County, Indiana

    Science.gov (United States)

    Bobay, K.E.

    1988-01-01

    The groundwater beneath eight sewage sludge lagoons, was studied to characterize the flow regime and to determine whether leachate had infiltrated into the glacio-fluvial sediments. Groundwater quality beneath the lagoons was compared with the groundwater quality beneath a landfill where sludge had been applied. The lagoons and landfills overlie outwash sand and gravel deposits separated by discontinuous clay layers. Shallow groundwater flows away from the lagoons and discharges into the White River. Deep groundwater discharges to the White River and flows southwest beneath Eagle Creek. After an accumulation of at least 2 inches of precipitation during 1 week, groundwater flow is temporarily reversed in the shallow aquifer, and all deep flow is along a relatively steep hydraulic gradient to the southwest. The groundwater is predominantly a calcium bicarbonate type, although ammonium accounts for more than 30% of the total cations in water from three wells. Concentrations of sodium, chloride, sulfate, iron, arsenic, boron, chemical oxygen demand, total dissolved solids, and methylene-blue-active substances indicate the presence of leachate in the groundwater. Concentrations of cadmium, chromium, copper, lead, mercury, nickel, selenium, and zinc were less than detection limits. The concentrations of 16 of 19 constituents or properties of groundwater beneath the lagoons are statistically different than groundwater beneath the landfill at the 0.05 level of significance. Only pH and concentrations of dissolved oxygen and bromide are higher in groundwater beneath the landfill than beneath the lagoons. 

  8. 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.

  9. 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

  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 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

  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 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

  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. The relationship of the Yucca Mountain repository block to the regional ground-water system: A geochemical model

    International Nuclear Information System (INIS)

    Yucca Mountain, in southern Nevada, is being studied by the Department of Energy and the State of Nevada as the site of a high-level nuclear waste repository. Geochemical and isotopic modeling were used in this study to define the relationship of the volcanic tuff aquifers and aquitards to the underlying regional carbonate ground-water system. The chemical evolution of a ground water as it passes through a hypothetical tuffaceous aquifer was developed using computer models PHREEQE, WATEQDR and BALANCE. The tuffaceous system was divided into five parts, with specific mineralogies, reaction steps and temperatures. The initial solution was an analysis of a soil water from Rainier Mesa. The ending solution in each part became the initial solution in the next part. Minerals consisted of zeolites, smectites, authigenic feldspars and quartz polymorphs from described diagentic mineral zones. Reaction steps were ion exchange with zeolites. The solution from the final zone, Part V, was chosen as most representative, in terms of pH, element molalities and mineral solubilities, of tuffaceous water. This hypothetical volcanic water from Part V was mixed with water from the regional carbonate aquifer, and the results compared to analyses of Yucca Mountain wells. Mixing and modeling attempts were conducted on wells in which studies indicated upward flow

  15. Geophysical investigation of seepage beneath an earthen dam.

    Science.gov (United States)

    Ikard, S J; Rittgers, J; Revil, A; Mooney, M A

    2015-01-01

    A hydrogeophysical survey is performed at small earthen dam that overlies a confined aquifer. The structure of the dam has not shown evidence of anomalous seepage internally or through the foundation prior to the survey. However, the surface topography is mounded in a localized zone 150 m downstream, and groundwater discharges from this zone periodically when the reservoir storage is maximum. We use self-potential and electrical resistivity tomography surveys with seismic refraction tomography to (1) determine what underlying hydrogeologic factors, if any, have contributed to the successful long-term operation of the dam without apparent indicators of anomalous seepage through its core and foundation; and (2) investigate the hydraulic connection between the reservoir and the seepage zone to determine whether there exists a potential for this success to be undermined. Geophysical data are informed by hydraulic and geotechnical borehole data. Seismic refraction tomography is performed to determine the geometry of the phreatic surface. The hydro-stratigraphy is mapped with the resistivity data and groundwater flow patterns are determined with self-potential data. A self-potential model is constructed to represent a perpendicular profile extending out from the maximum cross-section of the dam, and self-potential data are inverted to recover the groundwater velocity field. The groundwater flow pattern through the aquifer is controlled by the bedrock topography and a preferential flow pathway exists beneath the dam. It corresponds to a sandy-gravel layer connecting the reservoir to the downstream seepage zone.

  16. 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

  17. 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.

  18. Groundwater processes, sandplain seeps and interactions with regional aquifer systems in South-Western Australia

    Science.gov (United States)

    George, Richard J.

    1992-06-01

    Groundwater systems were studied in the 4200 ha East Belka catchment in a dryland farming area 300 km east of Perth, W.A., to determine the cause of sandplain seeps. Detailed investigations were carried out on a 200 ha hillslope to determine the characteristics of a shallow aquifer system responsible for the salinization of previously productive agricultural soils. The impact of the shallow aquifer on the regional system was investigated. A shallow (less than 8 m), perched, perennial aquifer was encountered in the deep sandplain materials. Groundwater discharge of about 1000 kl year -1 from the perched aquifer maintained saline soils across a 5 ha sandplain seep. Perching is due to the decreased permeability, geometry and silicification of the top of the mottled and pallid zones, and the convergence of perched ground waters near the seep. Slug test measurements suggest that the sandplain soils have a relatively low hydraulic conductivity (0.15 m day -1). Water qualities in the perched aquifer ranged from brackish to saline (3000-8000 mg l -1 TDS), peaking in the salt-affected area (12 000 mg l -1 TDS). High nitrate and Cl/Br ratios occur in the shallow aquifer and in the regional ground water beneath the sandplain seep. Recharge to the deep aquifer takes place throughout the catchment, but is greatest beneath the sandplain seep, where a perennial groundwater mound occurs. Recharge to the regional aquifer was estimated to be 6 to 15 mm year -1, increasing to between 20 and 60 mm year -1 beneath the seep. By contrast, less than 0.3 mm year -1 is able to leave the catchment as regional groundwater flow. Water-levels in the deep bores are consequently rising by 0.05 to 0.25 m year -1. Recharge to the deep aquifer beneath the seep, and low groundwater gradients, create the potential for groundwater flow to take place beneath the topographic divide and towards the adjoining catchment. However, as the vertical flux to the aquifer is two orders of magnitude greater than

  19. YUCCA auxin biosynthetic genes are required for Arabidopsis shade avoidance

    Science.gov (United States)

    Müller-Moulé, Patricia; Nozue, Kazunari; Pytlak, Melissa L.; Palmer, Christine M.; Covington, Michael F.; Wallace, Andreah D.; Harmer, Stacey L.

    2016-01-01

    Plants respond to neighbor shade by increasing stem and petiole elongation. Shade, sensed by phytochrome photoreceptors, causes stabilization of PHYTOCHROME INTERACTING FACTOR proteins and subsequent induction of YUCCA auxin biosynthetic genes. To investigate the role of YUCCA genes in phytochrome-mediated elongation, we examined auxin signaling kinetics after an end-of-day far-red (EOD-FR) light treatment, and found that an auxin responsive reporter is rapidly induced within 2 hours of far-red exposure. YUCCA2, 5, 8, and 9 are all induced with similar kinetics suggesting that they could act redundantly to control shade-mediated elongation. To test this hypothesis we constructed a yucca2, 5, 8, 9 quadruple mutant and found that the hypocotyl and petiole EOD-FR and shade avoidance responses are completely disrupted. This work shows that YUCCA auxin biosynthetic genes are essential for detectable shade avoidance and that YUCCA genes are important for petiole shade avoidance. PMID:27761349

  20. Extreme ground motions and Yucca Mountain

    Science.gov (United States)

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

    2013-01-01

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

  1. 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

  2. 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.

  3. 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

  4. 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

  5. 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

  6. 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.

  7. 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

  8. 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.

  9. Predicting the Future at Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    J. R. Wilson

    1999-07-01

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

  10. Data Package for Past and Current Groundwater Flow and Contamination beneath Single-Shell Tank Waste Management Areas

    Energy Technology Data Exchange (ETDEWEB)

    Horton, Duane G.

    2007-03-16

    This appendix summarizes historic and recent groundwater data collected from the uppermost aquifer beneath the 200 East and 200 West Areas. Although the area of interest is the Hanford Site Central Plateau, most of the information discussed in this appendix is at the scale of individual single-shell tank waste management areas. This is because the geologic, and thus the hydraulic, properties and the geochemical properties (i.e., groundwater composition) are different in different parts of the Central Plateau.

  11. 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

  12. Total-system performance assessment for Yucca Mountain -- SNL second iteration (TSPA-1993)

    International Nuclear Information System (INIS)

    Sandia National Laboratories has completed the second iteration of the periodic total-system performance assessments (TSPA-93) for the Yucca Mountain Site Characterization Project (YMP). Scenarios describing expected conditions (aqueous and gaseous transport of contaminants) and low-probability events (human-intrusion drilling and volcanic intrusion) are modeled. The hydrologic processes modeled include estimates of the perturbations to ambient conditions caused by heating of the repository resulting from radioactive decay of the waste. TSPA-93 incorporates significant new detailed process modeling, including two- and three-dimensional modeling of thermal effects, groundwater flow in the saturated-zone aquifers, and gas flow in the unsaturated zone. Probabilistic analyses are performed for aqueous and gaseous flow and transport, human intrusion, and basaltic magmatic activity. Results of the calculations lead to a number of recommendations concerning studies related to site characterization. Primary among these are the recommendations to obtain better information on percolation flux at Yucca Mountain, on the presence or absence of flowing fractures, and on physical and chemical processes influencing gaseous flow. Near-field thermal and chemical processes, and waste-container degradation are also areas where additional investigations may reduce important uncertainties. Recommendations for repository and waste-package design studies are: (1) to evaluate the performance implications of large-size containers, and (2) to investigate in more detail the implications of high repository thermal power output on the adjacent host rock and on the spent fuel

  13. 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

  14. Value of information analysis for Corrective Action Unit 97: Yucca Flat, Nevada Test Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    IT Corporation Las Vegas

    1999-11-19

    The value-of-information analysis evaluated data collection options for characterizing groundwater transport of contamination associated with the Yucca Flat and Climax Mine Corrective Action Units. Experts provided inputs for the evaluation of 48 characterization options, which included 27 component activities, 12 combinations of activities (subgroups), and 9 combinations of subgroups (groups). The options range from an individual study using existing data and intended to address a relatively narrow uncertainty to a 52-million dollar group of activities designed to collect and analyze new information to broadly address multiple uncertainties. A modified version of the contaminant transport component of the regional model was used to simulate contaminant transport and to estimate the maximum extent of the contaminant boundary, defined as that distance beyond which the committed effective dose equivalent from the residual radionuclides in groundwater will not exceed 4 millirem per year within 1,000 years. These simulations identified the model parameters most responsible for uncertainty over the contaminant boundary and determined weights indicating the relative importance of these parameters. Key inputs were identified through sensitivity analysis; the five selected parameters were flux for flow into Yucca Flat from the north, hydrologic source term, effective porosity and diffusion parameter for the Lower Carbonate Aquifer, and path length from the Volcanic Confining Unit to the Lower Carbonate Aquifer. Four measures were used to quantify uncertainty reduction. Using Bayesian analysis, the options were compared and ranked based on their costs and estimates of their effectiveness at reducing the key uncertainties relevant to predicting the maximum contaminant boundary.

  15. Value of information analysis for Corrective Action Unit 97: Yucca Flat, Nevada Test Site, Nevada

    International Nuclear Information System (INIS)

    The value-of-information analysis evaluated data collection options for characterizing groundwater transport of contamination associated with the Yucca Flat and Climax Mine Corrective Action Units. Experts provided inputs for the evaluation of 48 characterization options, which included 27 component activities, 12 combinations of activities (subgroups), and 9 combinations of subgroups (groups). The options range from an individual study using existing data and intended to address a relatively narrow uncertainty to a 52-million dollar group of activities designed to collect and analyze new information to broadly address multiple uncertainties. A modified version of the contaminant transport component of the regional model was used to simulate contaminant transport and to estimate the maximum extent of the contaminant boundary, defined as that distance beyond which the committed effective dose equivalent from the residual radionuclides in groundwater will not exceed 4 millirem per year within 1,000 years. These simulations identified the model parameters most responsible for uncertainty over the contaminant boundary and determined weights indicating the relative importance of these parameters. Key inputs were identified through sensitivity analysis; the five selected parameters were flux for flow into Yucca Flat from the north, hydrologic source term, effective porosity and diffusion parameter for the Lower Carbonate Aquifer, and path length from the Volcanic Confining Unit to the Lower Carbonate Aquifer. Four measures were used to quantify uncertainty reduction. Using Bayesian analysis, the options were compared and ranked based on their costs and estimates of their effectiveness at reducing the key uncertainties relevant to predicting the maximum contaminant boundary

  16. The Integration and Abstracyion of EBS Models in Yucca Mountain Performance Assessment

    Energy Technology Data Exchange (ETDEWEB)

    S.D. Sevougian; V. Jain; A.V. Luik

    2006-01-11

    The safety strategy for geological disposal of radioactive waste at Yucca Mountain relies on a multi-barrier system to contain the waste and isolate it from the biosphere. The multi-barrier system consists of the natural barrier provided by the geological setting and the engineered barrier system (EBS). In the case of Yucca Mountain (YM) the geologic setting is the unsaturated-zone host rock, consisting of about 600 meters of layered ash-flow volcanic tuffs above the water table, and the saturated zone beneath the water table. Both the unsaturated and saturated rocks are part of a closed hydrologic basin in a desert surface environment. The waste is to be buried about halfway between the desert surface and the water table. The primary engineered barriers at YM consist of metal components that are highly durable in an oxidizing environment. The two primary components of the engineered barrier system are highly corrosion-resistant metal waste packages, made from a nickel-chromium-molybdenum alloy, Alloy 22, and titanium drip shields that protect the waste packages from corrosive dripping water and falling rocks. Design and performance assessment of the EBS requires models that describe how the EBS and near field behave under anticipated repository-relevant conditions. These models must describe coupled hydrologic, thermal, chemical, and mechanical (THCM) processes that drive radionuclide transport in a highly fractured host rock, consisting of a relatively permeable network of conductive fractures in a setting of highly impermeable tuff rock matrix. An integrated performance assessment of the EBS must include a quantification of the uncertainties that arise from (1) incomplete understanding of processes and (2) from lack of data representative of the large spatial scales and long time scales relevant to radioactive waste disposal (e.g., long-term metal corrosion rates and heterogeneities in rock properties over the large 5 km{sup 2} emplacement area of the repository

  17. EPA Sole Source Aquifers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Information on sole source aquifers (SSAs) is widely used in assessments under the National Environmental Policy Act and at the state and local level. A national...

  18. Lower Cretaceous aquifers

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the Lower Cretaceous aquifers in the states of Montana, Wyoming, South Dakota, Kansas, Nebraska, Iowa, and Minnesota..

  19. Mississippi embayment aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the Mississippi embayment aquifer system in the states of Louisiana, Arkansas, Mississippi, Alabama, Tennessee, and Kentucky.

  20. Early Mesozoic basin aquifers

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the Early Mesozoic basin aquifers in the states of Massachusettes, Connecticut, New York, New Jersey, Pennsylvania, Maryland,...

  1. Ogallala Aquifer Mapping Program

    International Nuclear Information System (INIS)

    A computerized data file has been established which can be used efficiently by the contour-plotting program SURFACE II to produce maps of the Ogallala aquifer in 17 counties of the Texas Panhandle. The data collected have been evaluated and compiled into three sets, from which SURFACE II can generate maps of well control, aquifer thickness, saturated thickness, water level, and the difference between virgin (pre-1942) and recent (1979 to 1981) water levels. 29 figures, 1 table

  2. Yucca mountain project getter program results(year 1):I-129 and other anions of concern.

    Energy Technology Data Exchange (ETDEWEB)

    Krumhansl, James Lee; Pless, Jason; Chwirka, J. Benjamin

    2006-07-01

    Although high level nuclear wastes (HLW) contain a daunting array of radioisotopes, only a restricted number are long-lived enough to be problematic, and of these many are either effectively insoluble or are likely to be scavenged from solution by minerals indigenous to all aquifers. Those few constituents likely to travel significant distances through aquifers either form colloids (and travel as particulates) or anions--which are not sorbed onto the predominantly negatively charged mineral surfaces. Iodine ({sup 129}I) is one such constituent and may travel as either iodide (I{sup -}) or iodate (IO{sub 3}{sup -}) depending on whether conditions are mildly reducing or oxidizing. Conventionally, {sup 99}Tc (traveling as TcO{sub 4}{sup -}) is regarded as being of greater concern since it is both more abundant and has a shorter half life (e.g., has a higher specific activity). However, it is unclear whether TcO{sub 4}{sup -} will ever actually form in the mildly reducing environments thought likely within degrading HLW canisters. Instead, technetium may remain reduced as highly insoluble Tc(IV), in which case {sup 129}I might become a significant risk driver in performance assessment (PA) calculations. In the 2004-2005 time frame the US Department of Energy (DOE)--Office of Civilian Radioactive Waste Management (OCRUM), Office of Science and Technology International (S&T) funded a program to identify ''getters'' for possible placement in the invert beneath HLW packages in the repository being planned by the Yucca Mountain Project (YMP). This document reports on progress made during the first (and only) year of this activity. The problem is not a new one and the project did not proceed in a complete vacuum of information. Potential leads came from past studies directed at developing anion getters for a near surface low-level waste facility at Hanford, which suggested that both copper-containing compounds and hydrotalcite-group minerals might be

  3. 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

  4. 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

  5. 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.

  6. 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

  7. Three-dimensional conceptual model for the Hanford Site unconfined aquifer system: FY 1994 status report

    Energy Technology Data Exchange (ETDEWEB)

    Thorne, P.D.; Chamness, M.A.; Vermeul, V.R.; Macdonald, Q.C.; Schubert, S.E.

    1994-11-01

    This report documents work conducted during the fiscal year 1994 to development an improved three-dimensional conceptual model of ground-water flow in the unconfined aquifer system across the Hanford Site Ground-Water Surveillance Project, which is managed by Pacific Northwest Laboratory. The main objective of the ongoing effort to develop an improved conceptual model of ground-water flow is to provide the basis for improved numerical report models that will be capable of accurately predicting the movement of radioactive and chemical contaminant plumes in the aquifer beneath Hanford. More accurate ground-water flow models will also be useful in assessing the impacts of changes in facilities and operations. For example, decreasing volumes of operational waste-water discharge are resulting in a declining water table in parts of the unconfined aquifer. In addition to supporting numerical modeling, the conceptual model also provides a qualitative understanding of the movement of ground water and contaminants in the aquifer.

  8. 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

  9. 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

  10. 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.

  11. 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)

  12. 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.

  13. Specific yield, High Plains aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents specific-yield ranges in the High Plains aquifer of the United States. The High Plains aquifer underlies 112.6 million acres...

  14. Aquifer stability investigations

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R.D.; Doherty, T.J.

    1981-09-01

    The study of compressed air energy storage (CAES) in porous rock reservoirs is carried out within the Reservoir Stability Studies Program at Pacific Northwest Laboratory. The goal of the study is to establish criteria for long-term stability of aquifer CAES reservoirs. These criteria are intended to be guidelines and check lists that utilities and architect-engineering firms may use to evaluate reservoir stability at candidate CAES sites. These criteria will be quantitative where possible, qualitative where necessary, and will provide a focal point for CAES relevant geotechnical knowledge, whether developed within this study or available from petroleum, mining or other geotechnical practices using rock materials. The Reservoir Stability Studies Program had four major activities: a state-of-the-art survey to establish preliminary stability criteria and identify areas requiring research and development; numerical modeling; laboratory testing to provide data for use in numerical models and to investigate fundamental rock mechanics, thermal, fluid, and geochemical response of aquifer materials; and field studies to verify the feasibility of air injection and recovery under CAES conditions in an aquifer, to validate and refine the stability criteria, and to evaluate the accuracy and adequacy of the numerical and experimental methodologies developed in previous work. Three phases of study, including preliminary criteria formulation, numerical model development, and experimental assessment of CAES reservoir materials have been completed. Present activity consists of construction and operation of the aquifer field test, and associated numerical and experimental work in support of that activity. Work is presently planned to be complete by 1983 at the end of the field test. At that time the final stability criteria for aquifers will be issued. Attached here also are preliminary criteria for aquifers.

  15. Sustainability of natural attenuation of nitrate in agricultural aquifers

    Science.gov (United States)

    Green, Christopher T.; Bekins, Barbara A.

    2010-01-01

    Increased concentrations of nitrate in groundwater in agricultural areas, coinciding with increased use of chemical and organic fertilizers, have raised concern because of risks to environmental and human health. At some sites, these problems are mitigated by natural attenuation of nitrate as a result of microbially mediated reactions. Results from U.S. Geological Survey (USGS) research under the National Water-Quality Assessment (NAWQA) program show that reactions of dissolved nitrate with solid aquifer minerals and organic carbon help lower nitrate concentrations in groundwater beneath agricultural fields. However, increased fluxes of nitrate cause ongoing depletion of the finite pool of solid reactants. Consumption of the solid reactants diminishes the capacity of the aquifer to remove nitrate, calling into question the long-term sustainability of these natural attenuation processes.

  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. 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

  18. A Hydrostratigraphic Model and Alternatives for the Groundwater Flow and Contaminant Transport Model of Corrective Action Unit 97: Yucca Flat-Climax Mine, Lincoln and Nye Counties, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Geotechnical Sciences Group Bechtel Nevada

    2006-01-01

    A new three-dimensional hydrostratigraphic framework model for the Yucca Flat-Climax Mine Corrective Action Unit was completed in 2005. The model area includes Yucca Flat and Climax Mine, former nuclear testing areas at the Nevada Test Site, and proximal areas. The model area is approximately 1,250 square kilometers in size and is geologically complex. Yucca Flat is a topographically closed basin typical of many valleys in the Basin and Range province. Faulted and tilted blocks of Tertiary-age volcanic rocks and underlying Proterozoic and Paleozoic sedimentary rocks form low ranges around the structural basin. During the Cretaceous Period a granitic intrusive was emplaced at the north end of Yucca Flat. A diverse set of geological and geophysical data collected over the past 50 years was used to develop a structural model and hydrostratigraphic system for the basin. These were integrated using EarthVision? software to develop the 3-dimensional hydrostratigraphic framework model. Fifty-six stratigraphic units in the model area were grouped into 25 hydrostratigraphic units based on each unit's propensity toward aquifer or aquitard characteristics. The authors organized the alluvial section into 3 hydrostratigraphic units including 2 aquifers and 1 confining unit. The volcanic units in the model area are organized into 13 hydrostratigraphic units that include 8 aquifers and 5 confining units. The underlying pre-Tertiary rocks are divided into 7 hydrostratigraphic units, including 3 aquifers and 4 confining units. Other units include 1 Tertiary-age sedimentary confining unit and 1 Mesozoic-age granitic confining unit. The model depicts the thickness, extent, and geometric relationships of these hydrostratigraphic units (''layers'' in the model) along with the major structural features (i.e., faults). The model incorporates 178 high-angle normal faults of Tertiary age and 2 low-angle thrust faults of Mesozoic age. The complexity of the model

  19. Imaging of subducted lithosphere beneath South America

    NARCIS (Netherlands)

    Engdahl, E.R.; Hilst, R.D. van der; Berrocal, J.

    1995-01-01

    Tomographic images are produced for the deep structure of the Andean subduction zone beneath western South America. The data used in the imaging are the delay times of P, pP and pwP phases from relocated teleseismic earthquakes in the region. Regionally, structural features larger than about 150 km

  20. Horizontal and vertical distribution of contaminant solvents introduced during different periods into coastal plain aquifers

    International Nuclear Information System (INIS)

    Within a 10 square mile sector in the NW part of the Savannah River Site, degreasing solvents, trichloroethylene (TCE) and tetrachloroethylene (PCE) from contaminant plumes primarily within Tertiary Coastal Plain strata. In the central area, TCE has migrated farther down-section than PCE; to the north, TCE concentrations are > PCE, although both are significantly lower. SW groundwater flow characterizes aquifers beneath the region. Vertical migration potentials are downward. Within the central area, maximum contaminant concentrations are confined to the upper part of the Steed Pond aquifer. Wells do not penetrate deep enough in the central area to determine if contaminants > 5 ppb occur below the 30-50 ft thick Crouch Branch confining unit (CBcu). In the NE part of the sector, the confining layers are thinner, and contaminants are in the Crouch Branch aquifer (CRa) beneath the CBcu. The plume originating from the NE part of the area extends steeply downward to a 360+ ft depth below the surface (30--20 ft above mean sea level), and extends laterally as two distinct lobes of high concentration in the Middle Sand aquifer zone (MSa) within the CBcu and in the CBa in the Cretaceous part of the stratigraphic section. The plume extending beneath the NE part of the area has the deepest known vertical extent. The PCE plume shows relatively moderate levels of contamination extending down to the Middle Sand aquifer zone, but only very low concentrations at deeper levels. In the central part of the area, multiple plumes of high contaminant concentration are steeply inclined from the vertical in the Steed Pond aquifer, whereas high concentrations of PCE do not show as much areal distribution as TCE

  1. Localized sulfate-reducing zones in a coastal plain aquifer

    Science.gov (United States)

    Brown, C.J.; Coates, J.D.; Schoonen, M.A.A.

    1999-01-01

    High concentrations of dissolved iron in ground water of coastal plain or alluvial aquifers contribute to the biofouling of public supply wells for which treatment and remediation is costly. Many of these aquifers, however, contain zones in which microbial sulfate reduction and the associated precipitation of iron-sulfide minerals decreases iron mobility. The principal water-bearing aquifer (Magothy Aquifer of Cretaceous age) in Suffolk County, New York, contains localized sulfate-reducing zones in and near lignite deposits, which generally are associated with clay lenses. Microbial analyses of core samples amended with [14C]-acetate indicate that microbial sulfate reduction is the predominant terminal-electron-accepting process (TEAP) in poorly permeable, lignite-rich sediments at shallow depths and near the ground water divide. The sulfate-reducing zones are characterized by abundant lignite and iron-sulfide minerals, low concentrations of Fe(III) oxyhydroxides, and by proximity to clay lenses that contain pore water with relatively high concentrations of sulfate and dissolved organic carbon. The low permeability of these zones and, hence, the long residence time of ground water within them, permit the preservation and (or) allow the formation of iron-sulfide minerals, including pyrite and marcasite. Both sulfate-reducing bacteria (SRB) and iron-reducing bacteria (IRB) are present beneath and beyond the shallow sulfate-reducing zones. A unique Fe(III)-reducing organism, MD-612, was found in core sediments from a depth of 187 m near the southern shore of Long Island. The distribution of poorly permeable, lignite-rich, sulfate-reducing zones with decreased iron concentration is varied within the principal aquifer and accounts for the observed distribution of dissolved sulfate, iron, and iron sulfides in the aquifer. Locating such zones for the placement of production wells would be difficult, however, because these zones are of limited aerial extent.

  2. Summary of Radionuclide Reactive Transport Experiments in Fractured Tuff and Carbonate Rocks from Yucca Flat, Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Zavarin, M; Roberts, S; Reimus, P; Johnson, M

    2006-10-11

    In the Yucca Flat basin of the Nevada Test Site (NTS), 747 shaft and tunnel nuclear detonations were conducted primarily within the tuff confining unit (TCU) or the overlying alluvium. The TCU in the Yucca Flat basin is hypothesized to inhibit radionuclide migration to the highly transmissive and regionally extensive lower carbonate aquifer (LCA) due to its wide-spread aerial extent, low permeability, and chemical reactivity. However, fast transport pathways through the TCU by way of fractures may provide a migration path for radionuclides to the LCA. Radionuclide transport in both TCU and the LCA fractures is likely to determine the location of the contaminant boundary for the Yucca Flat/Climax Mine Corrective Action Unit (CAU). Radionuclide transport through the TCU may involve both matrix and fracture flow. However, radionuclide migration over significant distances is likely to be dominated by fracture transport. Transport through the LCA will almost certainly be dominated by fracture flow, as the LCA has a very dense, low porosity matrix with very low permeability. Because of the complex nature of reactive transport in fractures, a stepwise approach to identifying mechanisms controlling radionuclide transport was used. The simplest LLNL experiments included radionuclide transport through synthetic parallel-plate fractured tuff and carbonate cores. These simplified fracture transport experiments isolated matrix diffusion and sorption effects from all other fracture transport processes (fracture lining mineral sorption, heterogeneous flow, etc.). Additional fracture transport complexity was added by performing induced fractured LCA flowthrough experiments (effect of aperture heterogeneity) or iron oxide coated parallel plate TCU flowthrough experiments (effect of fracture lining minerals). Finally naturally fractured tuff and carbonate cores were examined at LLNL and LANL. All tuff and carbonate core used in the experiments was obtained from the USGS Core Library

  3. Imaging Magma Plumbing Beneath Askja Volcano, Iceland

    Science.gov (United States)

    Greenfield, T. S.; White, R. S.

    2015-12-01

    Using a dense seismic network we have imaged the plumbing system beneath Askja, a large central volcano in the Northern Volcanic Zone, Iceland. Local and regional earthquakes have been used as sources to solve for the velocity structure beneath the volcano. We find a pronounced low-velocity anomaly beneath the caldera at a depth of ~7 km around the depth of the brittle-ductile transition. The anomaly is ~10% slower than the initial best fitting 1D model and has a Vp/Vs ratio higher than the surrounding crust, suggesting the presence of increased temperature or partial melt. We use relationships between mineralogy and seismic velocities to estimate that this region contains ~10% partial melt, similar to observations made at other volcanoes such as Kilauea. This low-velocity body is deeper than the depth range suggested by geodetic studies of a deflating source beneath Askja. Beneath the large low-velocity zone a region of reduced velocities extends into the lower crust and is coincident with seismicity in the lower crust. This is suggestive of a high temperature channel into the lower crust which could be the pathway for melt rising from the mantle. This melt either intrudes into the lower crust or stalls at the brittle-ductile boundary in the imaged body. Above this, melt can travel into the fissure swarm through large dikes or erupt within the Askja caldera itself.We generate travel time tables using a finite difference technique and the residuals used to simultaneously solve for both the earthquake locations and velocity structure. The 2014-15 Bárðarbunga dike intrusion has provided a 45 km long, distributed source of large earthquakes which are well located and provide accurate arrival time picks. Together with long-term background seismicity these provide excellent illumination of the Askja volcano from all directions.hhhh

  4. Yucca schidigera and Quillaja saponaria supplementation in broiler diets

    Science.gov (United States)

    Yucca schidigera and quillaja saponaria are both rich in saponins and polyphenolic compounds, and have been associated with supplementary effects that improve livestock production with some ammonia emission reduction characteristics. Thus, a broiler study evaluated live performance, carcass characte...

  5. 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)

  6. 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

  7. 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

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. Magma Plumbing beneath Askja Volcano, Iceland

    Science.gov (United States)

    Greenfield, T. S.; White, R. S.

    2013-12-01

    Through a combination of accurate earthquake locations and tomography we have imaged the melt feeding network beneath Askja, a large central volcano, in the Northern Volcanic Zone, Iceland. We have deployed and operated a dense network of 3-component, broadband seismometers around the volcano since 2006 and have recorded a large number of events (on the order of 150 a day). The majority of these are due to an extensive geothermal area within the caldera and tectonically induced earthquakes to the northeast which are not related to the magma plumbing system. More intriguing are the less numerous deeper earthquakes situated in three distinct areas within the volcanic system. These have a lower frequency content to the shallower events which may be the result of highly attenuating lower crust. The deep earthquakes extend from 12-25 km depth, significantly below a well defined brittle-ductile boundary at 8-9 km. These earthquakes indicate the presence of melt moving or degassing at depth as only high strain rates or increased pore fluid pressures would cause brittle fracture in what is normally an aseismic region in the ductile zone. To image the structure beneath Askja, local and regional earthquakes have been used as sources to solve for the velocity structure beneath the volcano. Travel-time tables were created using a finite difference technique and the residuals were used to solve simultaneously for both the earthquake locations and velocity structure. Results showed a pronounced low-velocity anomaly beneath the caldera at a depth of ~5 km. The anomaly is ~10% slower than the initial best fitting 1D model and has a Vp/Vs ratio higher than the surrounding crust, suggesting the presence of increased temperature or partial melt. The body is unlikely to be entirely melt as S-waves are still detected at stations directly above the anomaly. This low-velocity body is slightly deeper than the depth range suggested by InSAR and GPS studies of a deflating source beneath

  14. Total-system performance assessment for Yucca Mountain - SNL second iteration (TSPA-1993)

    International Nuclear Information System (INIS)

    Sandia National Laboratories has completed the second iteration of the periodic total-system performance assessments (TSPA-93) for the Yucca Mountain Site Characterization Project (YMP). These analyses estimate the future behavior of a potential repository for high-level nuclear waste at the Yucca Mountain, Nevada, site under consideration by the Department of Energy. TSPA-93 builds upon previous efforts by emphasizing YMP concerns relating to site characterization, design, and regulatory compliance. Scenarios describing expected conditions (aqueous and gaseous transport of contaminants) and low-probability events (human-intrusion drilling and volcanic intrusion) are modeled. The hydrologic processes modeled include estimates of the perturbations to ambient conditions caused by heating of the repository resulting from radioactive decay of the waste. Hydrologic parameters and parameter probability distributions have been derived from available site data. Possible future climate changes are modeled by considering two separate groundwater infiltration conditions: open-quotes wetclose quotes with a mean flux of 10 mm/yr, and open-quotes dryclose quotes with a mean flux of 0.5 mm/yr. Two alternative waste-package designs and two alternative repository areal thermal power densities are investigated. One waste package is a thin-wall container emplaced in a vertical borehole, and the second is a container designed with corrosion-resistant and corrosion-allowance walls emplaced horizontally in the drift. Thermal power loadings of 57 kW/acre (the loading specified in the original repository conceptual design) and 114 kW/acre (a loading chosen to investigate effects of a open-quotes hot repositoryclose quotes) are considered. TSPA-93 incorporates significant new detailed process modeling, including two- and three-dimensional modeling of thermal effects, groundwater flow in the saturated-zone aquifers, and gas flow in the unsaturated zone

  15. Total-system performance assessment for Yucca Mountain - SNL second iteration (TSPA-1993); Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, M.L.; Gauthier, J.H.; Barnard, R.W.; Barr, G.E.; Dockery, H.A.; Dunn, E.; Eaton, R.R.; Guerin, D.C.; Lu, N.; Martinez, M.J. [and others

    1994-04-01

    Sandia National Laboratories has completed the second iteration of the periodic total-system performance assessments (TSPA-93) for the Yucca Mountain Site Characterization Project (YMP). These analyses estimate the future behavior of a potential repository for high-level nuclear waste at the Yucca Mountain, Nevada, site under consideration by the Department of Energy. TSPA-93 builds upon previous efforts by emphasizing YMP concerns relating to site characterization, design, and regulatory compliance. Scenarios describing expected conditions (aqueous and gaseous transport of contaminants) and low-probability events (human-intrusion drilling and volcanic intrusion) are modeled. The hydrologic processes modeled include estimates of the perturbations to ambient conditions caused by heating of the repository resulting from radioactive decay of the waste. Hydrologic parameters and parameter probability distributions have been derived from available site data. Possible future climate changes are modeled by considering two separate groundwater infiltration conditions: {open_quotes}wet{close_quotes} with a mean flux of 10 mm/yr, and {open_quotes}dry{close_quotes} with a mean flux of 0.5 mm/yr. Two alternative waste-package designs and two alternative repository areal thermal power densities are investigated. One waste package is a thin-wall container emplaced in a vertical borehole, and the second is a container designed with corrosion-resistant and corrosion-allowance walls emplaced horizontally in the drift. Thermal power loadings of 57 kW/acre (the loading specified in the original repository conceptual design) and 114 kW/acre (a loading chosen to investigate effects of a {open_quotes}hot repository{close_quotes}) are considered. TSPA-93 incorporates significant new detailed process modeling, including two- and three-dimensional modeling of thermal effects, groundwater flow in the saturated-zone aquifers, and gas flow in the unsaturated zone.

  16. Total-system performance assessment for Yucca Mountain - SNL second iteration (TSPA-1993); Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, M.L.; Barnard, R.W.; Barr, G.E.; Dockery, H.A.; Dunn, E.; Eaton, R.R.; Martinez, M.J. [Sandia National Labs., Albuquerque, NM (United States); Gauthier, J.H.; Guerin, D.C.; Lu, N. [and others

    1994-04-01

    Sandia National Laboratories has completed the second iteration of the periodic total-system performance assessments (TSPA-93) for the Yucca Mountain Site Characterization Project (YMP). These analyses estimate the future behavior of a potential repository for high-level nuclear waste at the Yucca Mountain, Nevada, site under consideration by the Department of Energy. TSPA-93 builds upon previous efforts by emphasizing YMP concerns relating to site characterization, design, and regulatory compliance. Scenarios describing expected conditions (aqueous and gaseous transport of contaminants) and low-probability events (human-intrusion drilling and volcanic intrusion) are modeled. The hydrologic processes modeled include estimates of the perturbations to ambient conditions caused by heating of the repository resulting from radioactive decay of the waste. Hydrologic parameters and parameter probability distributions have been derived from available site data. Possible future climate changes are modeled by considering two separate groundwater infiltration conditions: {open_quotes}wet{close_quotes} with a mean flux of 10 mm/yr, and {open_quotes}dry{close_quotes} with a mean flux of 0.5 mm/yr. Two alternative waste-package designs and two alternative repository areal thermal power densities are investigated. One waste package is a thin-wall container emplaced in a vertical borehole, and the second is a container designed with corrosion-resistant and corrosion-allowance walls emplaced horizontally in the drift. Thermal power loadings of 57 kW/acre (the loading specified in the original repository conceptual design) and 114 kW/acre (a loading chosen to investigate effects of a {open_quotes}hot repository{close_quotes}) are considered. TSPA-93 incorporates significant new detailed process modeling, including two- and three-dimensional modeling of thermal effects, groundwater flow in the saturated-zone aquifers, and gas flow in the unsaturated zone.

  17. Oceanographic conditions beneath Fimbul Ice Shelf, Antarctica

    OpenAIRE

    Abrahamsen, Einar Povl

    2012-01-01

    Antarctic ice shelves play a key role in the global climate system, acting as important sites for the cooling of shelf waters, thereby facilitating deep and bottom water formation. Many of the processes that take place under large ice shelves can be observed more conveniently beneath smaller ice shelves such as Fimbul Ice Shelf, an ice shelf in the eastern Weddell Sea. Fimbul Ice Shelf and nearby ice shelves might also play a significant regional role: although no bottom water is produced in ...

  18. REACTIVE MULTIPHASE BEHAVIOR OF CO2 IN SALINE AQUIFERS BENEATH THE COLORADO PLATEAU

    Energy Technology Data Exchange (ETDEWEB)

    R.G. Allis; J. Moore; S. White

    2003-06-30

    The six coal-fired power plants located in the Colorado Plateau and southern Rocky Mountain region of the U.S. produce 100 million tons of CO{sub 2} per year. Thick sequences of collocated sedimentary rocks represent potential sites for sequestration of the CO{sub 2}. Field and laboratory investigations of naturally occurring CO{sub 2}-reservoirs are being conducted to determine the characteristics of potential seal and reservoir units and the extent of the interactions that occur between the host rocks and the CO{sub 2} charged fluids. The results are being incorporated into a series of two-dimensional numerical models that represent the major chemical and physical processes induced by injection. During reporting period covered here (March 30 to June 30, 2003), the main achievements were: Presentation of three papers at the Second Annual Conference on Carbon Sequestration (May 5-8, Alexandria, Virginia); Presentation of a poster at the American Association of Petroleum Geologists meeting; Co-PI organized and chaired a special session on Geologic Carbon Dioxide Sequestration at the American Association of Petroleum Geologists annual convention in Salt Lake City (May 12-15).

  19. REACTIVE MULTIPHASE BEHAVIOR OF CO2 IN SALINE AQUIFERS BENEATH THE COLORADO PLATEAU

    Energy Technology Data Exchange (ETDEWEB)

    R.G. Allis; J. Moore; S. White

    2005-05-16

    Soil CO{sub 2} flux surveys have been conducted over known CO{sub 2} reservoirs at Farnham Dome, Utah, Crystal Geyser-Ten Mile Graben in Utah and Springerville-St. Johns, Arizona. No anomalous CO{sub 2} flux was detected at the Farnham Dome and Springerville-St. Johns. At Crystal Geyser-Ten Mile Graben, localized areas of anomalously high CO{sub 2} flux ({approx}100 g m{sup -2} day{sup -1}) occur along a fault zone near visibly degassing features. Isotopic measurements on CO{sub 2} collected from nearby springs indicate that it originated at depth. Evidence of widespread vein calcite at the surface (Farnham Dome) and travertine deposits at the other two areas suggests that discharge of CO{sub 2}-rich fluids has occurred in the past. Despite the lack of evidence for significant present day leakage of CO{sub 2} to the atmosphere at Springerville-St. Johns and Crystal Geyser-Ten Mile Graben, there are significant outflows of high-bicarbonate water in both areas suggesting continuous migration of CO{sub 2} in the aqueous phase from depth. The very localized nature of the CO{sub 2} flux anomalies, and the outflow of ground water containing dissolved CO{sub 2} present challenges for effective, long term monitoring of CO{sub 2} leakage.

  20. Subsurface imaging reveals a confined aquifer beneath an ice-sealed Antarctic lake

    DEFF Research Database (Denmark)

    Dugan, H. A.; Doran, P. T.; Tulaczyk, S.;

    2015-01-01

    Liquid water oases are rare under extreme cold desert conditions found in the Antarctic McMurdo Dry Valleys. Here we report geophysical results that indicate that Lake Vida, one of the largest lakes in the region, is nearly frozen and underlain by widespread cryoconcentrated brine. A ground...

  1. Nitrogen sources and sinks in a wastewater impacted saline aquifer beneath the Florida Keys, USA

    Science.gov (United States)

    Dillon, Kevin S.; Chanton, Jeffrey P.; Smith, Leslie K.

    2007-06-01

    Groundwater wells surrounding a high volume advance treatment wastewater (ATW) disposal well in the Florida Keys were monitored for nitrate, nitrite, and ammonium concentrations over a 14 month period. Nutrient concentrations in the shallow subsurface (9 m) show a bimodal distribution between the low salinity wastewater plume and the ambient brackish to saline groundwaters. High NO 3- concentrations are found within the ATW plume while the highest NH 4+ concentrations are found in shallow wells outside of the plume. Evidence suggests that the overlying mud layer unique to this study site contributes the bulk of the NH 4+ observed in these wells. NO 3- concentrations at 9 m wells varied by a factor of four in response to concurrent variations in ATW NO 3- loads over the coarse of the study. Estimated NO 3- uptake rates varied from 32 ± 29 to 98 ± 69 and did not directly correlate with ATW NO 3- loading as we hypothesized. We estimate that 70 ± 34% of the NO 3- from the treatment plant is removed from solution in the subsurface of the study site. Considerable decreases in NO 3- concentration and enrichment of 15NO 3- was observed in many wells, indicating significant denitrification or anaerobic ammonium oxidation is occurring in the subsurface. Dissolved inorganic nitrogen concentrations, distributions, and 15N compositions indicate that denitrification is likely the dominant mechanism for N removal in the ATW plume at Key Colony Beach, Florida.

  2. Analysis of Ground-Water Levels and Associated Trends in Yucca Flat, Nevada Test Site, Nye County, Nevada, 1951-2003

    Energy Technology Data Exchange (ETDEWEB)

    J.M. Fenelon

    2005-10-05

    Almost 4,000 water-level measurements in 216 wells in the Yucca Flat area from 1951 to 2003 were quality assured and analyzed. An interpretative database was developed that describes water-level conditions for each water level measured in Yucca Flat. Multiple attributes were assigned to each water-level measurement in the database to describe the hydrologic conditions at the time of measurement. General quality, temporal variability, regional significance, and hydrologic conditions are attributed for each water-level measurement. The database also includes narratives that discuss the water-level history of each well. Water levels in 34 wells were analyzed for variability and for statistically significant trends. An attempt was made to identify the cause of many of the water-level fluctuations or trends. Potential causes include equilibration following well construction or development, pumping in the monitoring well, withdrawals from a nearby supply well, recharge from precipitation, earthquakes, underground nuclear tests, land subsidence, barometric pressure, and Earth tides. Some of the naturally occurring fluctuations in water levels may result from variations in recharge. The magnitude of the overall water-level change for these fluctuations generally is less than 2 feet. Long-term steady-state hydrographs for most of the wells open to carbonate rock have a very similar pattern. Carbonate-rock wells without the characteristic pattern are directly west of the Yucca and Topgallant faults in the southwestern part of Yucca Flat. Long-term steady-state hydrographs from wells open to volcanic tuffs or the Eleana confining unit have a distinctly different pattern from the general water-level pattern of the carbonate-rock aquifers. Anthropogenic water-level fluctuations were caused primarily by water withdrawals and nuclear testing. Nuclear tests affected water levels in many wells. Trends in these wells are attributed to test-cavity infilling or the effects of

  3. Preliminary hydrogeologic assessment of boreholes UE-25c No. 1, UE-25c No. 2, and UE-25c No. 3, Yucca Mountain, Nye County, Nevada

    International Nuclear Information System (INIS)

    The purpose of this report is to characterize-the hydrogeology of saturated tuffaceous rocks penetrated by boreholes UE-25c number-sign 1, UE-25c number-sign 2, and UE-25c number-sign 3. These boreholes are referred to collectively in this report as the C-holes. The C-holes were drilled to perform multiwell aquifer tests and tracer tests; they comprise the only complex of closely spaced boreholes completed in the saturated zone at Yucca Mountain. Results of lithologic and geophysical logging, fracture analyses, water-level monitoring, temperature and tracejector surveys aquifer tests, and hydrochemical sampling completed at the C-hole complex as of 1986 are assessed with respect to the regional geologic and hydrologic setting. A conceptual hydrogeological model of the Yucca Mountain area is presented to provide a context for quantitatively evaluating hydrologic tests performed at the C-hole complex as of 1985, for planning and interpreting additional hydrologic tests at the C-hole complex, and for possibly re-evaluating hydrologic tests in boreholes other than the C-holes

  4. Preliminary hydrogeologic assessment of boreholes UE-25c No. 1, UE-25c No. 2, and UE-25c No. 3, Yucca Mountain, Nye County, Nevada

    International Nuclear Information System (INIS)

    The purpose of this report is to characterize the hydrogeology of saturated tuffaceous rocks penetrated by boreholes UE-25c No. 1, UE-25c No.2, and UE-25c No. 3. These boreholes are referred to collectively in this report as the C-holes. The C-holes were drilled to perform multiwell aquifer tests and tracer tests; they comprise the only complex of closely spaced boreholes completed in the saturated zone at Yucca Mountain. Results of lithologic and geophysical logging, fracture analyses, water-level monitoring, temperature and tracejector surveys, aquifer tests, and hydrochemical sampling completed at the C-hole complex as of 1986 are assessed with respect to the regional geologic and hydrologic setting. A conceptual hydrogeological model of the Yucca Mountain area is presented to provide a context for quantitatively evaluating hydrologic tests performed at the C-hole complex as of 1985, for planning and interpreting additional hydrologic tests at the C-hole complex, and for possibly re-evaluating hydrologic tests in boreholes other than the C-holes

  5. Quality of groundwater in the Denver Basin aquifer system, Colorado, 2003-5

    Science.gov (United States)

    Musgrove, MaryLynn; Beck, Jennifer A.; Paschke, Suzanne; Bauch, Nancy J.; Mashburn, Shana L.

    2014-01-01

    Groundwater resources from alluvial and bedrock aquifers of the Denver Basin are critical for municipal, domestic, and agricultural uses in Colorado along the eastern front of the Rocky Mountains. Rapid and widespread urban development, primarily along the western boundary of the Denver Basin, has approximately doubled the population since about 1970, and much of the population depends on groundwater for water supply. As part of the National Water-Quality Assessment Program, the U.S. Geological Survey conducted groundwater-quality studies during 2003–5 in the Denver Basin aquifer system to characterize water quality of shallow groundwater at the water table and of the bedrock aquifers, which are important drinking-water resources. For the Denver Basin, water-quality constituents of concern for human health or because they might otherwise limit use of water include total dissolved solids, fluoride, sulfate, nitrate, iron, manganese, selenium, radon, uranium, arsenic, pesticides, and volatile organic compounds. For the water-table studies, two monitoring-well networks were installed and sampled beneath agricultural (31 wells) and urban (29 wells) land uses at or just below the water table in either alluvial material or near-surface bedrock. For the bedrock-aquifer studies, domestic- and municipal-supply wells completed in the bedrock aquifers were sampled. The bedrock aquifers, stratigraphically from youngest (shallowest) to oldest (deepest), are the Dawson, Denver, Arapahoe, and Laramie-Fox Hills aquifers. The extensive dataset collected from wells completed in the bedrock aquifers (79 samples) provides the opportunity to evaluate factors and processes affecting water quality and to establish a baseline that can be used to characterize future changes in groundwater quality. Groundwater samples were analyzed for inorganic, organic, isotopic, and age-dating constituents and tracers. This report discusses spatial and statistical distributions of chemical constituents

  6. Magnetotelluric Data, Central Yucca Flat, Nevada Test Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    J.M. Williams; B.D. Rodriguez, and T.H. Asch

    2005-11-23

    Nuclear weapons are integral to the defense of the United States. The U.S. Department of Energy, as the steward of these devices, must continue to gauge the efficacy of the individual weapons. This could be accomplished by occasional testing at the Nevada Test Site (NTS) in Nevada, northwest of Las Vegas. Yucca Flat Basin is one of the testing areas at the NTS. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow in the area subsequent to a nuclear test. Ground-water modelers would like to know more about the hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Yucca Flat Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey (USGS) collected and processed Magnetotelluric (MT) and Audio-magnetotelluric (AMT) data at the Nevada Test Site in and near Yucca Flat to help characterize this pre-Tertiary geology. That work will help to define the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (UCCU) in the Yucca Flat area. Interpretation will include a three-dimensional (3-D) character analysis and two-dimensional (2-D) resistivity model. The purpose of this report is to release the MT sounding data for Central Yucca Flat, Profile 1, as shown in figure 1. No interpretation of the data is included here.

  7. Magnetotelluric Data, Southern Yucca Flat, Nevada Test Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    J.M. Williams; B.D. Rodriguez, and T.H. Asch

    2005-11-23

    Nuclear weapons are integral to the defense of the United States. The U.S. Department of Energy, as the steward of these devices, must continue to gauge the efficacy of the individual weapons. This could be accomplished by occasional testing at the Nevada Test Site (NTS) in Nevada, northwest of Las Vegas. Yucca Flat Basin is one of the testing areas at the NTS. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow in the area subsequent to a nuclear test. Ground-water modelers would like to know more about the hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Yucca Flat Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey (USGS) collected and processed Magnetotelluric (MT) and Audio-magnetotelluric (AMT) data at the Nevada Test Site in and near Yucca Flat to help characterize this pre-Tertiary geology. That work will help to define the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (UCCU) in the Yucca Flat area. Interpretation will include a three-dimensional (3-D) character analysis and two-dimensional (2-D) resistivity model. The purpose of this report is to release the MT sounding data for Southern Yucca Flat, Profile 4, as shown in Figure 1. No interpretation of the data is included here.

  8. Sole Source Aquifers for NY and NJ

    Data.gov (United States)

    U.S. Environmental Protection Agency — This layer is the designated sole source aquifers of New York and New Jersey. A Sole Source Aquifer, is an aquifer that supplies 50% or more of the drinking water...

  9. Analysis of groundwater flow beneath ice sheets

    Energy Technology Data Exchange (ETDEWEB)

    Boulton, G. S.; Zatsepin, S.; Maillot, B. [Univ. of Edinburgh (United Kingdom). Dept. of Geology and Geophysics

    2001-03-01

    The large-scale pattern of subglacial groundwater flow beneath European ice sheets was analysed in a previous report. It was based on a two-dimensional flowline model. In this report, the analysis is extended to three dimensions by exploring the interactions between groundwater and tunnel flow. A theory is developed which suggests that the large-scale geometry of the hydraulic system beneath an ice sheet is a coupled, self-organising system. In this system the pressure distribution along tunnels is a function of discharge derived from basal meltwater delivered to tunnels by groundwater flow, and the pressure along tunnels itself sets the base pressure which determines the geometry of catchments and flow towards the tunnel. The large-scale geometry of tunnel distribution is a product of the pattern of basal meltwater production and the transmissive properties of the bed. The tunnel discharge from the ice margin of the glacier, its seasonal fluctuation and the sedimentary characteristics of eskers are largely determined by the discharge of surface meltwater which penetrates to the bed in the terminal zone. The theory explains many of the characteristics of esker systems and can account for tunnel valleys. It is concluded that the large-scale hydraulic regime beneath ice sheets is largely a consequence of groundwater/tunnel flow interactions and that it is essential similar to non-glacial hydraulic regimes. Experimental data from an Icelandic glacier, which demonstrates measured relationships between subglacial tunnel flow and groundwater flow during the transition from summer to winter seasons for a modern glacier, and which support the general conclusions of the theory is summarised in an appendix.

  10. 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

  11. 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.

  12. Short seed longevity, variable germination conditions, and infrequent establishment events provide a narrow window for Yucca brevifolia (Agavaceae) recruitment

    Science.gov (United States)

    Bryant, M.; Reynolds, J.; DeFalco, Lesley A.; Esque, Todd C.

    2012-01-01

    PREMISE OF THE STUDY: The future of long-lived stand-forming desert plants such as Yucca brevifolia (Joshua tree) has come into question in light of climate variation and landscape-scale disturbances such as wildfire. Understanding plant establishment dynamics is important for mitigating the impacts of disturbances and promoting revegetation. • METHODS: We placed Y. brevifolia seeds in shallow caches and manipulated granivore access, nurse shrub effects, and the season of cache placement to determine conditions for seed germination and seedling establishment. • KEY RESULTS: Greatest seedling emergence occurred during spring and summer, when increased soil moisture was accompanied by warm soil temperatures. Late winter-spring emergence for cached seeds was enhanced beneath shrub canopies, but seedling survival declined beneath shrubs as temperatures increased in spring. Germinability of seed remaining in the soil was reduced from 50-68% after 12 mo residence time in soil and declined to seeds are either removed by granivores or lose germinability, imposing substantial losses of potential germinants. • CONCLUSIONS: Specific germination and establishment requirements impose stringent limits on recruitment rates for Y. brevifolia. Coupled with infrequent seed availability, the return rates to prefire densities and demographic structure may require decades to centuries, especially in light of potential changes to regional desert climate in combination with the potential for fire recurrence. Demographic patterns are predicted to vary spatially in response to environmental variability that limits recruitment and may already be apparent among extant populations.

  13. Hydrochemical evolution of sodium-sulfate and sodium-chloride groundwater beneath the Northern Chihuahuan Desert, Trans-Pecos, Texas, USA

    Science.gov (United States)

    Fisher, R.S.; Mullican, W. F., III

    1997-01-01

    Groundwater beneath the northern Chihuahuan Desert, Trans-Pecos, Texas, USA, occurs in both carbonate and siliciclastic aquifers beneath a thick unsaturated zone and in shallow Rio Grande alluvium. Groundwater hydrochemical evolution was investigated by analyzing soils, soil leachates, bolson-fill sediments, water from the unsaturated zone, and groundwater from three major aquifers. Ionic relations, mineral saturation states, and geochemical modeling show that groundwater compositions are controlled by reactions in the unsaturated zone, mineralogy of unsaturated sediments and aquifers, position in the groundwater flow system, and extensive irrigation. Recharge to aquifers unaffected by irrigation is initially a Ca-HCO3 type as a result of dissolving carbonate surficial salts. With continued flow and mineral-water interaction, saturation with calcite and dolomite is maintained, gypsum is dissolved, and aqueous Ca and Mg are exchanged for adsorbed Na to produce a Na-SO4 water. Groundwater in Rio Grande alluvium is a Na-Cl type, reflecting river-water composition and the effects of irrigation, evapotranspiration, and surficial salt recycling. These results document two hydrochemical evolution paths for groundwater in arid lands. If recharge is dilute precipitation, significant changes in water chemistry can occur in unsaturated media, ion exchange can be as important as dissolution-precipitation reactions in determining groundwater composition, and mineral-water reactions ultimately control groundwater composition. If recharge is return flow of irrigation water that already contains appreciable solutes, mineral-water reactions are less important than irrigation-water composition in determining groundwater chemistry.

  14. High Temperature Aquifer Storage

    Science.gov (United States)

    Ueckert, Martina; Niessner, Reinhard; Baumann, Thomas

    2016-04-01

    Combined heat and power generation (CHP) is highly efficient because excess heat is used for heating and/or process energy. However, the demand of heat energy varies considerably throughout the year while the demand for electrical energy is rather constant. It seems economically and ecologically highly beneficial for municipalities and large power consumers such as manufacturing plants to store excess heat in groundwater aquifers and to recuperate this energy at times of higher demand. Within the project High Temperature Aquifer Storage, scientists investigate storage and recuperation of excess heat energy into the bavarian Malm aquifer. Apart from high transmissivity and favorable pressure gradients, the hydrochemical conditions are crucial for long-term operation. An enormous technical challenge is the disruption of the carbonate equilibrium - modeling results indicated a carbonate precipitation of 10 - 50 kg/d in the heat exchangers. The test included five injection pulses of hot water (60 °C up to 110 °C) and four tracer pulses, each consisting of a reactive and a conservative fluorescent dye, into a depth of about 300 m b.s.l. resp. 470 m b.s.l. Injection and production rates were 15 L/s. To achieve the desired water temperatures, about 4 TJ of heat energy were necessary. Electrical conductivity, pH and temperature were recorded at a bypass where also samples were taken. A laboratory container at the drilling site was equipped for analysing the concentration of the dyes and the major cations at sampling intervals of down to 15 minutes. Additional water samples were taken and analysed in the laboratory. The disassembled heat exchanger prooved that precipitation was successfully prevented by adding CO2 to the water before heating. Nevertheless, hydrochemical data proved both, dissolution and precipitation processes in the aquifer. This was also suggested by the hydrochemical modelling with PhreeqC and is traced back to mixture dissolution and changing

  15. 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.

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. 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

  6. The geological storage of spent nuclear fuel and depleted uranium beneath the Williston Basin

    Energy Technology Data Exchange (ETDEWEB)

    Brunskill, B. [Helix Geological Consultants, Regina, SK (Canada)

    2007-07-01

    In order to prevent or retard the leakage of buried nuclear material into the surrounding rocks, regulatory agencies in Canada and the United States are recommending that spent nuclear fuel eventually be stored in suitable geological repositories with highly-engineered barriers. This presentation discussed the development of a repository somewhere in the Precambrian Shield beneath the Williston Basin in Canada, as well as a repository that was under construction at Yucca Mountain, Nevada, in the United States. Potential storage sites in Canada were provided in an illustration and a figure of the proposed repository development was provided. Other illustrations included a light-water fuel rod and assembly as well as storage containers and drip shield. It was shown that in order to prevent potential migration, it would be highly beneficial if a repository were located where the groundwater surrounding the repository was not vertically mobile. A map of the Williston Basin boundary and a fluid-flow model and alternate model through the Williston Basin were also presented. The primary benefits of developing a deep geological repository were presented. These included a favourable hydrogeological regime which would likely isolate and contain the eventual release of any radioactive material. Other benefits that were discussed included minimal disturbance to the geological media during development; elimination of most underground-related mining construction; and, radiation safety issues. tabs., figs.

  7. Yucca Mountain Project Getter Program Results (Year 1) I-I29 and Other Anions of Concern

    Energy Technology Data Exchange (ETDEWEB)

    J.L. Krumhansl; J.D. Pless; J.B. Chwirka; K.C. Holt

    2006-07-17

    Although high level nuclear wastes (HLW) contain a daunting array of radioisotopes, only a restricted number are long-lived enough to be problematic, and of these many are either effectively insoluble or are likely to be scavenged from solution by minerals indigenous to all aquifers. Those few constituents likely to travel significant distances through aquifers either form colloids (and travel as particulates) or anions--which are not sorbed onto the predominantly negatively charged mineral surfaces. Iodine ({sup 129}I) is one such constituent and may travel as either iodide (I{sup -}) or iodate (IO{sub 3}{sup -}) depending on whether conditions are mildly reducing or oxidizing. Conventionally, {sup 99}Tc (traveling as TcO{sub 4}{sup 0}) is regarded as being of greater concern since it is both more abundant and has a shorter half life (e.g., has a higher specific activity). However, it is unclear whether TcO{sub 4}{sup -} will ever actually form in the mildly reducing environments thought likely within degrading HLW canisters. Instead, technetium may remain reduced as highly insoluble Tc(lV), in which case {sup 129}I might become a significant risk driver in performance assessment (PA) calculations. In the 2004-2005 time frame the US Department of Energy (DOE)--Office of Civilian Radioactive Waste Management (OCRUM), Office of Science and Technology International (S&T) funded a program to identify ''getters'' for possible placement in the invert beneath HLW packages in the repository being planned by the Yucca Mountain Project (YMP). This document reports on progress made during the first (and only) year of this activity. The problem is not a new one and the project did not proceed in a complete vacuum of information. Potential leads came from past studies directed at developing anion getters for a near surface low-level waste facility at Hanford, which suggested that both copper-containing compounds and hydrotalcite-group minerals might be

  8. 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

  9. Life Beneath Glacial Ice - Earth(!) Mars(?) Europa(?)

    Science.gov (United States)

    Allen, Carlton C.; Grasby, Stephen E.; Longazo, Teresa G.; Lisle, John T.; Beauchamp, Benoit

    2002-01-01

    We are investigating a set of cold springs that deposit sulfur and carbonate minerals on the surface of a Canadian arctic glacier. The spring waters and mineral deposits contain microorganisms, as well as clear evidence that biological processes mediate subglacial chemistry, mineralogy, and isotope fractionation . The formation of native sulphur and associated deposits are related to bacterially mediated reduction and oxidation of sulphur below the glacier. A non-volcanic, topography driven geothermal system, harboring a microbiological community, operates in an extremely cold environment and discharges through solid ice. Microbial life can thus exist in isolated geothermal refuges despite long-term subfreezing surface conditions. Earth history includes several periods of essentially total glaciation. lee in the near subsurface of Mars may have discharged liquid water in the recent past Cracks in the ice crust of Europa have apparently allowed the release of water to the surface. Chemolithotrophic bacteria, such as those in the Canadian springs, could have survived beneath the ice of "Snowball Earth", and life forms with similar characteristics might exist beneath the ice of Mars or Europa. Discharges of water from such refuges may have brought to the surface living microbes, as well as longlasting chemical, mineralogical, and isotopic indications of subsurface life.

  10. Imaging magma plumbing beneath Askja volcano, Iceland

    Science.gov (United States)

    Greenfield, Tim; White, Robert S.

    2015-04-01

    Volcanoes during repose periods are not commonly monitored by dense instrumentation networks and so activity during periods of unrest is difficult to put in context. We have operated a dense seismic network of 3-component, broadband instruments around Askja, a large central volcano in the Northern Volcanic Zone, Iceland, since 2006. Askja last erupted in 1961, with a relatively small basaltic lava flow. Since 1975 the central caldera has been subsiding and there has been no indication of volcanic activity. Despite this, Askja has been one of the more seismically active volcanoes in Iceland. The majority of these events are due to an extensive geothermal area within the caldera and tectonically induced earthquakes to the northeast which are not related to the magma plumbing system. More intriguing are the less numerous deeper earthquakes at 12-24km depth, situated in three distinct areas within the volcanic system. These earthquakes often show a frequency content which is lower than the shallower activity, but they still show strong P and S wave arrivals indicative of brittle failure, despite their location being well below the brittle-ductile boundary, which, in Askja is ~7km bsl. These earthquakes indicate the presence of melt moving or degassing at depth while the volcano is not inflating, as only high strain rates or increased pore fluid pressures would cause brittle fracture in what is normally an aseismic region in the ductile zone. The lower frequency content must be the result of a slower source time function as earthquakes which are both high frequency and low frequency come from the same cluster, thereby discounting a highly attenuating lower crust. To image the plumbing system beneath Askja, local and regional earthquakes have been used as sources to solve for the velocity structure beneath the volcano. Travel-time tables were created using a finite difference technique and the residuals were used to solve simultaneously for both the earthquake locations

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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.

  17. PRESSURE FLUCTUATIONS BENEATH SPATIAL HYDRAULIC JUMPS

    Institute of Scientific and Technical Information of China (English)

    YAN Zhong-min; ZHOU Chun-tian; LU Shi-qiang

    2006-01-01

    This article deals with statistical analysis of pressure fluctuations at the bottom of spatial hydraulic jumps with abrupt lateral expansions. The effects of the channel expansion ratio and inflow condition on the power spectral and dominant frequency were examined. Pressure data were recorded for different Froude numbers ranging from 3.52 to 6.86 and channel expansion ratios ranging from 1.5 to 3.0. A sampling frequency of 100 Hz was selected. The measurements were conducted in the bed of a glass-walled laboratory flume by means of pressure transducers and data acquisition systems. Power spectra as well as dominant frequency and some other statistical characteristics of fluctuating pressure beneath hydraulic jumps were obtained. Test results were compared with those of classical jump, which indicates that the peak frequencies and intensity coefficients of pressure fluctuations are higher than those of the corresponding classical jumps.

  18. Multidisciplinary approach to identify aquifer-peatland connectivity

    Science.gov (United States)

    Larocque, Marie; Pellerin, Stéphanie; Cloutier, Vincent; Ferlatte, Miryane; Munger, Julie; Quillet, Anne; Paniconi, Claudio

    2015-04-01

    In southern Quebec (Canada), wetlands sustain increasing pressures from agriculture, urban development, and peat exploitation. To protect both groundwater and ecosystems, it is important to be able to identify how, where, and to what extent shallow aquifers and wetlands are connected. This study focuses on peatlands which are especially abundant in Quebec. The objective of this research was to better understand aquifer-peatland connectivity and to identify easily measured indicators of this connectivity. Geomorphology, hydrogeochemistry, and vegetation were selected as key indicators of connectivity. Twelve peatland transects were instrumented and monitored in the Abitibi (slope peatlands associated with eskers) and Centre-du-Quebec (depression peatlands) regions of Quebec (Canada). Geomorphology, geology, water levels, water chemistry, and vegetation species were identified/measured on all transects. Flow conditions were simulated numerically on two typical transects. Results show that a majority of peatland transects receives groundwater from a shallow aquifer. In slope peatlands, groundwater flows through the organic deposits towards the peatland center. In depression peatlands, groundwater flows only 100-200 m within the peatland before being redirected through surface routes towards the outlet. Flow modeling and sensitivity analysis have identified that the thickness and hydraulic conductivity of permeable deposits close to the peatland and beneath the organic deposits influence flow directions within the peatland. Geochemical data have confirmed the usefulness of total dissolved solids (TDS) exceeding 14 mg/L as an indicator of the presence of groundwater within the peatland. Vegetation surveys have allowed the identification of species and groups of species that occur mostly when groundwater is present, for instance Carex limosa and Sphagnum russowii. Geomorphological conditions (slope or depression peatland), TDS, and vegetation can be measured

  19. Evidence for Active Subduction Beneath Gibraltar

    Science.gov (United States)

    Gutscher, M.; Malod, J. A.; Rehault, J.; Contrucci, I. M.; Klingelhoefer, F.; Victor, L. M.; Spakman, W.

    2002-12-01

    The Gibraltar arc encompasses the Betic - Rif mountain belts with outward directed thrusting, surrounding a zone of strong Neogene subsidence and crustal thinning in the Western Alboran Sea. The SISMAR marine seismic survey conducted in April 2001 acquired over 3000 km of 360-channel seismic data with a 4.5 km long streamer and 1000 km of wide-angle data recorded by ocean bottom seismometers (OBS), completely spanning the actively deforming region between the margins of Portugal and northwest Morocco. We report on results from this seismic survey which reveal a thick chaotic sedimentary mass west of Gibraltar to be an actively deforming accretionary wedge, with east dipping thrust faults disrupting the seafloor and soleing out to an east dipping decollement. New travel-time tomographic results image a continuous east dipping body with high seismic velocities (i.e. a cold slab of oceanic lithosphere) descending from the Atlantic domain of the Gulf of Cadiz, passing through intermediate depth (60 - 120 km) seismicity beneath the Gibraltar Arc and Western Alboran Sea, and merging with a region of deep focus earthquakes 600 - 660 km below Granada Spain. Together these provide compelling evidence for an active east dipping subduction zone. Slab rollback towards the west provides a plausible mechanism for extension and subsidence in the Alboran Sea, while the associated westward advance of the Gibraltar Arc drives compressional deformation in the accretionary wedge where active mud volcanoes have recently been discovered. Active subduction beneath Gibraltar should be considered as a possible candidate for the source of the destructive Lisbon great earthquake (M 8.5-9) and tsunami of 1755 which ravaged the coast of the Gulf of Cadiz.

  20. Major disruption of D″ beneath Alaska

    Science.gov (United States)

    Sun, Daoyuan; Helmberger, Don; Miller, Meghan S.; Jackson, Jennifer M.

    2016-05-01

    D″ represents one of the most dramatic thermal and compositional layers within our planet. In particular, global tomographic models display relatively fast patches at the base of the mantle along the circum-Pacific which are generally attributed to slab debris. Such distinct patches interact with the bridgmanite (Br) to post-bridgmanite (PBr) phase boundary to generate particularly strong heterogeneity at their edges. Most seismic observations for the D″ come from the lower mantle S wave triplication (Scd). Here we exploit the USArray waveform data to examine one of these sharp transitions in structure beneath Alaska. From west to east beneath Alaska, we observed three different characteristics in D″: (1) the western region with a strong Scd, requiring a sharp δVs = 2.5% increase; (2) the middle region with no clear Scd phases, indicating a lack of D″ (or thin Br-PBr layer); and (3) the eastern region with strong Scd phase, requiring a gradient increase in δVs. To explain such strong lateral variation in the velocity structure, chemical variations must be involved. We suggest that the western region represents relatively normal mantle. In contrast, the eastern region is influenced by a relic slab that has subducted down to the lowermost mantle. In the middle region, we infer an upwelling structure that disrupts the Br-PBr phase boundary. Such an interpretation is based upon a distinct pattern of travel time delays, waveform distortions, and amplitude patterns that reveal a circular-shaped anomaly about 5° across which can be modeled synthetically as a plume-like structure rising about 400 km high with a shear velocity reduction of ~5%, similar to geodynamic modeling predictions of upwellings.

  1. 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

  2. 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

  3. Bioremediation of RDX in the vadose zone beneath the Pantex Plant

    Energy Technology Data Exchange (ETDEWEB)

    Shull, T.L.; Speitel, G.E. Jr.; McKinney, D.C. [Univ. of Texas, Austin, TX (United States). Dept. of Civil Engineering

    1999-01-01

    The presence of dissolved high explosives (HE), in particular RDX and HMX, is well documented in the perched aquifer beneath the Pantex Plant, but the distribution of HE in the vadose zone has not yet been well defined. Although current remediation activities focus on the contamination in the perched aquifer, eventually regulatory concern is likely to turn to the residual contamination in the vadose zone. Sources of HE include the infiltration of past wastewater discharges from several HE-processing facilities through the ditch drainage system and leachate from former Landfill 3. With limited existing data on the HE distribution in the vadose zone and without preventive action, it must be assumed that residual HE could be leached into infiltrating water, providing a continuing supply of contamination to the perched aquifer. The purpose of this project was to more closely examine the fate and transport of HE in the vadose zone through mathematical modeling and laboratory experimentation. In particular, this report focuses on biodegradation as one possible fate of HE. Biodegradation of RDX in the vadose zone was studied because it is both present in highest concentration and is likely to be of the greatest regulatory concern. This study had several objectives: determine if indigenous soil organisms are capable of RDX biodegradation; determine the impact of electron acceptor availability and nutrient addition on RDX biodegradation; determine the extent of RDX mineralization (i.e., conversion to inorganic carbon) during biodegradation; and estimate the kinetics of RDX biodegradation to provide information for mathematical modeling of fate and transport.

  4. Hydrogeologic data and water-quality data from a thick unsaturated zone at a proposed wastewater-treatment facility site, Yucca Valley, San Bernardino County, California, 2008-11

    Science.gov (United States)

    O'Leary, David; Clark, Dennis A.; Izbicki, John A.

    2015-01-01

    The Hi-Desert Water District, in the community of Yucca Valley, California, is considering constructing a wastewater-treatment facility and using the reclaimed water to recharge the aquifer system through surface spreading. The Hi-Desert Water District is concerned with possible effects of this recharge on water quality in the underlying groundwater system; therefore, an unsaturated-zone monitoring site was constructed by the U.S. Geological Survey (USGS) to characterize the unsaturated zone, monitor a pilot-scale recharge test, and, ultimately, to monitor the flow of reclaimed water to the water table once the treatment facility is constructed.

  5. 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.

  6. Magnetotelluric Data, North Central Yucca Flat, Nevada Test Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    J.M. Williams; B.D. Rodriguez, and T.H. Asch

    2005-11-23

    Nuclear weapons are integral to the defense of the United States. The U.S. Department of Energy, as the steward of these devices, must continue to gauge the efficacy of the individual weapons. This could be accomplished by occasional testing at the Nevada Test Site (NTS) in Nevada, northwest of Las Vegas. Yucca Flat Basin is one of the testing areas at the NTS. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow in the area subsequent to a nuclear test. Ground-water modelers would like to know more about the hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Yucca Flat Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey (USGS) collected and processed Magnetotelluric (MT) and Audio-magnetotelluric (AMT) data at the Nevada Test Site in and near Yucca Flat to help characterize this pre-Tertiary geology. That work will help to define the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (UCCU) in the Yucca Flat area. Interpretation will include a three-dimensional (3-D) character analysis and two-dimensional (2-D) resistivity model. The purpose of this report is to release the MT sounding data for north central Yucca Flat, Profile 7, as shown in Figure 1. No interpretation of the data is included here.

  7. Magnetotelluric Data, Northern Yucca Flat, Nevada Test Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    J.M. Williams; B.D. Rodriguez, and T.H. Asch

    2005-11-23

    Nuclear weapons are integral to the defense of the United States. The U.S. Department of Energy, as the steward of these devices, must continue to gauge the efficacy of the individual weapons. This could be accomplished by occasional testing at the Nevada Test Site (NTS) in Nevada, northwest of Las Vegas. Yucca Flat Basin is one of the testing areas at the NTS. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow in the area subsequent to a nuclear test. Ground-water modelers would like to know more about the hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Yucca Flat Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey (USGS) collected and processed Magnetotelluric (MT) and Audio-magnetotelluric (AMT) data at the Nevada Test Site in and near Yucca Flat to help characterize this pre-Tertiary geology. That work will help to define the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (UCCU) in the Yucca Flat area. Interpretation will include a three-dimensional (3-D) character analysis and two-dimensional (2-D) resistivity model. The purpose of this report is to release the MT sounding data for Profile 2, (fig. 1), located in the northern Yucca Flat area. No interpretation of the data is included here.

  8. 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

  9. Hydrogeochemistry and isotopic tracing of nitrate contamination of two aquifer systems on Jeju Island, Korea.

    Science.gov (United States)

    Koh, Eun-Hee; Kaown, Dugin; Mayer, Bernhard; Kang, Bong-Rae; Moon, Hee Sun; Lee, Kang-Kun

    2012-01-01

    The groundwater of Jeju Island (Republic of Korea) is vulnerable to contamination because its aquifers are mainly composed of highly permeable geological units and its agricultural fields are often exposed to excessive use of predominantly synthetic fertilizers. In the Gosan area of Jeju Island, we investigated nitrate contamination in both a perched aquifer above an impermeable clay bed and the regional groundwater beneath this aquitard. The δO and δD values indicate that the perched groundwater is recharged by local precipitation, whereas the regional groundwater is recharged mainly by regional flow from an adjacent mountainous region. The perched groundwater contained very high NO-N concentrations of up to 87 mg/L. The isotopic composition of nitrate in the perched groundwater showed that synthetic fertilizers applied in high excesses of crop N needs were the main cause of aquifer pollution. Elevated nitrate concentrations were also observed in the regional groundwater especially after precipitation events. Concentration and isotopic data revealed that the inflow of shallow perched groundwater along the poorly cemented or uncemented annulus of regional groundwater wells was one of the main reasons for the nitrate contamination observed in the regional groundwater. In both aquifers, δN and δO values showed that the sources of nitrate were derived from synthetic fertilizers that had been recycled in the soil zone by nitrification and in some portions of the perched aquifer (dissolved oxygen concentrations <2 mg/L) indicated that denitrification occurred locally. PMID:23128740

  10. Mississippi River Valley alluvial aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the Mississippi River Valley alluvial aquifer in the states of Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and...

  11. (SUPERCEDED) High Plains aquifer (SUPERCEDED)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the High Plains aquifer in the states of South Dakota, Wyoming, Nebraska, Colorado, Kansas, New Mexico, Oklahoma, and Texas....

  12. Southeastern Coastal Plain aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the Southeastern Coastal Plain aquifer system in Kentucky, Tennessee, Mississippi, Alabama, Georgia, and South Carolina.

  13. Region 9 Sole Source Aquifers

    Data.gov (United States)

    U.S. Environmental Protection Agency — There are 7 polygons representing 6 individual sole source aquifer boundaries and one streamflow source area in California, Arizona, and Nevada. Various efforts...

  14. Digital data sets that describe aquifer characteristics of the Enid isolated terrace aquifer in northwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized aquifer boundaries for the Enid isolated terrace aquifer in northwestern Oklahoma. The Enid isolated terrace aquifer covers...

  15. Digital data sets that describe aquifer characteristics of the Elk City aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized aquifer boundaries for the Elk City aquifer in western Oklahoma. The aquifer covers an area of approximately 193,000 acres and...

  16. Microbial dynamics in natural aquifers

    OpenAIRE

    Bajracharya, Bijendra Man

    2016-01-01

    Microorganisms in groundwater form ecosystems that can transform chemical compounds. Quantitatively understanding microbial dynamics in soils and groundwater is thus essential for pollutant dynamics and biogeochemistry in the subsurface. This dissertation addresses three factors influencing microbial dynamics in aquifers and soils, namely: (1) the influence of grazing on bacteria in eutrophic aquifers, posing the question whether the carrying capacity of bacteria, which has been observed i...

  17. Investigating Late Cenozoic Mantle Dynamics beneath Yellowstone

    Science.gov (United States)

    Zhou, Q.; Liu, L.

    2015-12-01

    Recent tomography models (Sigloch, 2011; Schmandt & Lin, 2014) reveal unprecedented details of the mantle structure beneath the United States (U.S.). Prominent slow seismic anomalies below Yellowstone, traditionally interpreted as due to a mantle plume, are restricted to depths either shallower than 200 km or between 500 and 1000 km, but a continuation to greater depth is missing. Compared to fast seismic anomalies, which are usually interpreted as slabs or delaminated lithosphere, origin of deep slow seismic anomalies, especially those in the vicinity of subduction zones, is more enigmatic. As a consequence, both the dynamics and evolution of these slow anomalies remain poorly understood. To investigate the origin and evolution of the Yellowstone slow anomaly during the past 20 Myr, we construct a 4D inverse mantle convection model with a hybrid data assimilation scheme. On the one hand, we use the adjoint method to recover the past evolution of mantle seismic structures beyond the subduction zones. On the other hand, we use a high-resolution forward model to simulate the subduction of the oceanic (i.e., Farallon) plate. During the adjoint iterations, features from these two approaches are blended together at a depth of ~200 km below the subduction zone. In practice, we convert fast and slow seismic anomalies to effective positive and negative density heterogeneities. Our preliminary results indicate that at 20 Ma, the present-day shallow slow anomalies beneath the western U.S. were located inside the oceanic asthenosphere, which subsequently entered the mantle wedge, through the segmented Farallon slab. The eastward encroachment of the slow anomaly largely followed the Yellowstone hotspot track migration. The present deep mantle Yellowstone slow anomaly originated at shallower depths (i.e. transition zone), and was then translated down to the lower mantle accompanying the sinking fast anomalies. The temporal evolution of the slow anomalies suggests that the deep

  18. Channelization of plumes beneath ice shelves

    KAUST Repository

    Dallaston, M. C.

    2015-11-11

    © 2015 Cambridge University Press. We study a simplified model of ice-ocean interaction beneath a floating ice shelf, and investigate the possibility for channels to form in the ice shelf base due to spatial variations in conditions at the grounding line. The model combines an extensional thin-film description of viscous ice flow in the shelf, with melting at its base driven by a turbulent ocean plume. Small transverse perturbations to the one-dimensional steady state are considered, driven either by ice thickness or subglacial discharge variations across the grounding line. Either forcing leads to the growth of channels downstream, with melting driven by locally enhanced ocean velocities, and thus heat transfer. Narrow channels are smoothed out due to turbulent mixing in the ocean plume, leading to a preferred wavelength for channel growth. In the absence of perturbations at the grounding line, linear stability analysis suggests that the one-dimensional state is stable to initial perturbations, chiefly due to the background ice advection.

  19. Turbulence beneath finite amplitude water waves

    Energy Technology Data Exchange (ETDEWEB)

    Beya, J.F. [Universidad de Valparaiso, Escuela de Ingenieria Civil Oceanica, Facultad de Ingenieria, Valparaiso (Chile); The University of New South Wales, Water Research Laboratory, School of Civil and Environmental Engineering, Sydney, NSW (Australia); Peirson, W.L. [The University of New South Wales, Water Research Laboratory, School of Civil and Environmental Engineering, Sydney, NSW (Australia); Banner, M.L. [The University of New South Wales, School of Mathematics and Statistics, Sydney, NSW (Australia)

    2012-05-15

    Babanin and Haus (J Phys Oceanogr 39:2675-2679, 2009) recently presented evidence of near-surface turbulence generated below steep non-breaking deep-water waves. They proposed a threshold wave parameter a {sup 2}{omega}/{nu} = 3,000 for the spontaneous occurrence of turbulence beneath surface waves. This is in contrast to conventional understanding that irrotational wave theories provide a good approximation of non-wind-forced wave behaviour as validated by classical experiments. Many laboratory wave experiments were carried out in the early 1960s (e.g. Wiegel 1964). In those experiments, no evidence of turbulence was reported, and steep waves behaved as predicted by the high-order irrotational wave theories within the accuracy of the theories and experimental techniques at the time. This contribution describes flow visualisation experiments for steep non-breaking waves using conventional dye techniques in the wave boundary layer extending above the wave trough level. The measurements showed no evidence of turbulent mixing up to a value of a {sup 2}{omega}/{nu} = 7,000 at which breaking commenced in these experiments. These present findings are in accord with the conventional understandings of wave behaviour. (orig.)

  20. 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

  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. Active Subduction Beneath The Gibraltar Arc

    Science.gov (United States)

    Gutscher, M.-A.; Malod, J.; Rehault, J.-P.; Contrucci, I.; Klingelhoefer, F.; Spakman, W.; Sismar Scientific Team

    The Gibraltar region features the arcuate Betic - Rif mountain belt with outward di- rected thrusting, surrounding a zone of strong Neogene subsidence and crustal thin- ning in the Western Alboran Sea. Until now its geodynamic interpretation has re- mained controversial. The Gibraltar Arc is located at the eastern end of the Azores- Gibraltar transform, a diffuse transpressional plate boundary between the Iberian and African Plates. Attention has recently been focussed on this plate boundary, while seeking the likely source of the destructive Lisbon great earthquake (M 8.5 - 9) and tsunami of 1755. The SISMAR marine seismic survey conducted in April 2001 ac- quired over 3000 km of 360-channel seismic data with a 4.5 km long streamer and 1000 km of wide-angle data recorded by ocean bottom seismometers (OBS), com- pletely spanning the actively deforming region between the margins of Portugal and northwest Morocco. Results from this seismic survey reveal a thick chaotic sedimen- tary mass west of Gibraltar to be an actively deforming accretionary wedge, with east dipping thrust faults disrupting the seafloor and soleing out to an east dipping decolle- ment. New travel-time tomographic results image a continuous east dipping body with high seismic velocities (i.e. a cold slab of oceanic lithosphere) descending from the Atlantic domain of the Gulf of Cadiz, passing through intermediate depth (60 - 120 km) seismicity beneath the Gibraltar Arc and Western Alboran Sea, and merging with a region of deep focus earthquakes 600 - 660 km below Granada Spain. Together these provide compelling evidence for an active east dipping subduction zone. Slab rollback towards the west provides a plausible mechanism for extension and subsidence in the Alboran Sea, while the associated westward advance of the Gibraltar Arc drives com- pressional deformation in the accretionary wedge where active mud volcanoes have recently been discovered.

  3. Groundwater Mounding Beneath Stormwater Infiltration Basins

    Science.gov (United States)

    Nimmer, M.; Thompson, A. M.; Misra, D.

    2007-12-01

    An accurate understanding of groundwater mound formation is important in the proper design of stormwater infiltration basins since these basins are often required to recharge a portion of pre-development infiltration volume. Mound formation due to localized recharge may reduce the infiltration rate of the basin and the ability of the soil to filter pollutants. The goal of this research was to understand groundwater mounding and the potential for contaminant transport resulting from recharge beneath stormwater infiltration basins. A 0.10 ha infiltration basin serving a 9.4 ha residential subdivision in Oconomowoc, Wisconsin was used in this study. Subsurface conditions included sand and gravel material and a groundwater table at 2.3 m below grade. Three storm events, 4.9 cm, 2.8 cm, and 4.3 cm, between August 2006 and April 2007 were modeled using the two-dimensional numerical model HYDRUS. The calibrated model was used to evaluate hypothetical basin operation scenarios for various basin sizes, soil types, ponding depths, and water table depths. The groundwater mound intersected the basin floor in most scenarios with loamy sand and sandy loam soils, an unsaturated thickness of 1.52 m, and a ponding depth of 0.61 m. No groundwater table response was observed with ponding depths less than 0.31 m with an unsaturated zone thickness of 6.09 m. The mound height was most sensitive to hydraulic conductivity and unsaturated zone thickness. A 7.6 cm sediment layer delayed the time to reach maximum mound height, but had a minimal effect on the magnitude of the mound. Mound heights increased as infiltration basin size increased.

  4. Mantle Structure Beneath Central South America

    Science.gov (United States)

    Vandecar, J. C.; Silver, P. G.; James, D. E.; Assumpcao, M.; Schimmel, M.; Zandt, G.

    2003-12-01

    Making use of 60 digital broadband seismic stations that have operated across central South America in recent years, we have undertaken an inversion for the upper- and uppermost lower-mantle P- and S-wave velocity structures beneath the region. We have combined data from four portable PASSCAL-type experiments as well as the 3 GTSN permanent stations (LPAZ, BDFB and CPUP) and 1 Geoscope station (SPB) located in the region. The portable data were deployed at various times between 1992 and 1999 and include: 28 sites from the Brazilian Lithosphere Seismic Project (BLSP: Carnegie Institution of Washington and Universidade de Sao Paulo), 16 sites from the Broadband ANdean JOint experiment (BANJO: Carnegie Institution of Washington and University of Arizona), 8 sites from the Seismic Exploration of the Deep Altiplano project (SEDA: Lawrence Livermore National Laboratory) and 4 sites from the University of Brasilia. The P- and S-wave relative delay times are independently obtained via a multi-channel cross correlation of band-passed waveforms for each teleseismic event. These data are then inverted using an iterative, robust, non-linear scheme which parameterizes the 3-D velocity variations as splines under tension constrained at over 120,000 nodes across South America between latitudes of 15 and 30 degrees South. Amongst other features, we robustly image the high-velocity subducting Nazca plate penetrating into the lower mantle and the high-velocity root of the ~3.2 Gyr old Sao Francisco Craton extending to depths of 200-300 km. We will discuss the consistency between our tomographic models and predictions of dynamic mantle models based on plate tectonic reconstructions of subduction.

  5. 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.

  6. Yucca: A medicinally significant genus with manifold therapeutic attributes

    OpenAIRE

    Patel, Seema

    2012-01-01

    The genus Yucca comprising of several species is dominant across the chaparrals, canyons and deserts of American South West and Mexico. This genus has long been a source of sustenance and drugs for the Native Americans. In the wake of revived interest in drug discovery from plant sources, this genus has been investigated and startling nutritive and therapeutic capacities have come forth. Apart from the functional food potential, antioxidant, antiinflammation, antiarthritic, anticancer, antidi...

  7. 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.

  8. 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

  9. Numerical modeling of regional ground-water flow in the deep-basin brine aquifer of the Palo Duro Basin, Texas Panhandle

    International Nuclear Information System (INIS)

    Bedded Permian-age evaporite sequences in the Palo Duro Basin are being considered for a permanent nuclear waste repository by the U.S. Department of Energy. The purpose of this modeling study is to provide an understanding of regional ground-water flow in the formations beneath the Permian evaporite section. From this understanding, more detailed, smaller scale studies can be designed. This study is also intended to provide a better understanding of the boundary conditions and permeabilities of the aquifer and aquitard system as well as provide estimates of ground-water travel times across the basin. Numerical simulations were made of the Wolfcamp aquifer modeled as a single layer and of the entire Deep-Basin Brine aquifer system, including the Wolfcamp aquifer, modeled as a single layer

  10. Development of stochastic indicator models of lithology, Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Rautman, C.A. [Sandia National Labs., Albuquerque, NM (United States); Robey, T.H. [Spectra Research Inst., Albuquerque, NM (United States)

    1994-07-01

    Indicator geostatistical techniques have been used to produce a number of fully three-dimensional stochastic simulations of large-scale lithologic categories at the Yucca Mountain site. Each realization reproduces the available drill hole data used to condition the simulation. Information is propagated away from each point of observation in accordance with a mathematical model of spatial continuity inferred through soft data taken from published geologic cross sections. Variations among the simulated models collectively represent uncertainty in the lithology at unsampled locations. These stochastic models succeed in capturing many major features of welded-nonwelded lithologic framework of Yucca Mountain. However, contacts between welded and nonwelded rock types for individual simulations appear more complex than suggested by field observation, and a number of probable numerical artifacts exist in these models. Many of the apparent discrepancies between the simulated models and the general geology of Yucca Mountain represent characterization uncertainty, and can be traced to the sparse site data used to condition the simulations. Several vertical stratigraphic columns have been extracted from the three-dimensional stochastic models for use in simplified total-system performance assessment exercises. Simple, manual adjustments are required to eliminate the more obvious simulation artifacts and to impose a secondary set of deterministic geologic features on the overall stratigraphic framework provided by the indictor models.

  11. 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

  12. Mantle structure beneath the western edge of the Colorado Plateau

    Science.gov (United States)

    Sine, C.R.; Wilson, D.; Gao, W.; Grand, S.P.; Aster, R.; Ni, J.; Baldridge, W.S.

    2008-01-01

    Teleseismic traveltime data are inverted for mantle Vp and Vs variations beneath a 1400 km long line of broadband seismometers extending from eastern New Mexico to western Utah. The model spans 600 km beneath the moho with resolution of ???50 km. Inversions show a sharp, large-magnitude velocity contrast across the Colorado Plateau-Great Basin transition extending ???200 km below the crust. Also imaged is a fast anomaly 300 to 600 km beneath the NW portion of the array. Very slow velocities beneath the Great Basin imply partial melting and/or anomalously wet mantle. We propose that the sharp contrast in mantle velocities across the western edge of the Plateau corresponds to differential lithospheric modification, during and following Farallon subduction, across a boundary defining the western extent of unmodified Proterozoic mantle lithosphere. The deep fast anomaly corresponds to thickened Farallon plate or detached continental lithosphere at transition zone depths. Copyright 2008 by the American Geophysical Union.

  13. Saturated thickness, High Plains aquifer, 2009

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents the saturated thickness of the High Plains aquifer of the United States, 2009, in feet. The High Plains aquifer underlies...

  14. As contamination in Mercedes aquifer groundwater

    International Nuclear Information System (INIS)

    This work is about the quality of the groundwater an the arsenic content in different aquifers in Uruguay. The first data obtained of arsenic concentrations are from subterranes water in the Mercedes aquifers

  15. National Sole Source Aquifer GIS Layer

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data set contains indexes and Esri shape files of boundaries of the designated sole source aquifers and related aquifer boundaries. Data provide a vector...

  16. Foundering lithosphere imaged beneath the southern Sierra Nevada, California, USA.

    Science.gov (United States)

    Boyd, Oliver S; Jones, Craig H; Sheehan, Anne F

    2004-07-30

    Seismic tomography reveals garnet-rich crust and mantle lithosphere descending into the upper mantle beneath the southeastern Sierra Nevada. The descending lithosphere consists of two layers: an iron-rich eclogite above a magnesium-rich garnet peridotite. These results place descending eclogite above and east of high P wave speed material previously imaged beneath the southern Great Valley, suggesting a previously unsuspected coherence in the lithospheric removal process.

  17. Hydraulic Characterization of Overpressured Tuffs in Central Yucca Flat, Nevada Test Site, Nye County, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    K.J. Halford; R.J. Laczniak; D.L. Galloway

    2005-10-07

    A sequence of buried, bedded, air-fall tuffs has been used extensively as a host medium for underground nuclear tests detonated in the central part of Yucca Flat at the Nevada Test Site. Water levels within these bedded tuffs have been elevated hundreds of meters in areas where underground nuclear tests were detonated below the water table. Changes in the ground-water levels within these tuffs and changes in the rate and distribution of land-surface subsidence above these tuffs indicate that pore-fluid pressures have been slowly depressurizing since the cessation of nuclear testing in 1992. Declines in ground-water levels concurrent with regional land subsidence are explained by poroelastic deformation accompanying ground-water flow as fluids pressurized by underground nuclear detonations drain from the host tuffs into the overlying water table and underlying regional carbonate aquifer. A hydraulic conductivity of about 3 x 10-6 m/d and a specific storage of 9 x 10-6 m-1 are estimated using ground-water flow models. Cross-sectional and three-dimensional ground-water flow models were calibrated to measured water levels and to land-subsidence rates measured using Interferometric Synthetic Aperture Radar. Model results are consistent and indicate that about 2 million m3 of ground water flowed from the tuffs to the carbonate rock as a result of pressurization caused by underground nuclear testing. The annual rate of inflow into the carbonate rock averaged about 0.008 m/yr between 1962 and 2005, and declined from 0.005 m/yr in 2005 to 0.0005 m/yr by 2300.

  18. Hydraulic characterization of overpressured tuffs in central Yucca Flat, Nevada Test Site, Nye County, Nevada

    Science.gov (United States)

    Halford, Keith J.; Laczniak, Randell J.; Galloway, Devin L.

    2005-01-01

    A sequence of buried, bedded, air-fall tuffs has been used extensively as a host medium for underground nuclear tests detonated in the central part of Yucca Flat at the Nevada Test Site. Water levels within these bedded tuffs have been elevated hundreds of meters in areas where underground nuclear tests were detonated below the water table. Changes in the ground-water levels within these tuffs and changes in the rate and distribution of land-surface subsidence above these tuffs indicate that pore-fluid pressures have been slowly depressurizing since the cessation of nuclear testing in 1992. Declines in ground-water levels concurrent with regional land subsidence are explained by poroelastic deformation accompanying ground-water flow as fluids pressurized by underground nuclear detonations drain from the host tuffs into the overlying water table and underlying regional carbonate aquifer. A hydraulic conductivity of about 3 x 10-6 m/d and a specific storage of 9 x 10-6 m-1 are estimated using ground-water flow models. Cross-sectional and three-dimensional ground-water flow models were calibrated to measured water levels and to land-subsidence rates measured using Interferometric Synthetic Aperture Radar. Model results are consistent and indicate that about 2 million m3 of ground water flowed from the tuffs to the carbonate rock as a result of pressurization caused by underground nuclear testing. The annual rate of inflow into the carbonate rock averaged about 0.008 m/yr between 1962 and 2005, and declined from 0.005 m/yr in 2005 to 0.0005 m/yr by 2300.

  19. The effect of yucca on proliferation, apoptosis, and steroidogenesis of porcine ovarian granulosa cells

    Directory of Open Access Journals (Sweden)

    Aneta Štochmaľová

    2014-02-01

    Full Text Available Yucca shidigera is a medicinal plant native to Mexico. Is a plant widely used in folk medicine to treat a variety of ailmentary disorders, but its action on reproductive processes and possible mechanisms of such action remains unknown. Yucca schidigera extract contains a number of steroidal saponins that, because of their biological activity, have attracted attention from the food industry for many years. Yucca extract is used as a natural feed additive with positive effect to microflora, digestion, metabolism and to improve animal muscle growth. Its extract has been used as a foodstuff and folk medicine to treat a wide variety of diseases for many years. Nevertheless, it remaines unknown, whether consumption of yucca can affect reproductive system. The aim of this study was to examine the effects of yucca on basic ovarian cell functions - proliferation, apoptosis and steroidogenesis. Porcine ovarian granulosa cells were cultured with and without yucca extract (added at doses 0; 1; 10 and 100 μg.mL-1 of medium. Markers of proliferation (% of PCNA-positive cells and apoptosis (% cells containing bax were analysed by immunocytochemistry. Release of steroid hormones (progesterone and testosterone was measured by EIA. It was observed, that addition of yucca inhibited proliferation (expression of PCNA, increased apoptosis (expression of bax, stimulated progesterone and inhibited testosterone release. The ability of yucca to reduce ovarian cell proliferation, to promote ovarian cell apoptosis and affect steroidogenesis demonstrates the direct influence of yucca on female gonads. Furthermore, our observations suggest the multiple sites of action (proliferation, apoptosis, steroidogenesis of yucca on porcine ovarian cell functions. It is not to be excluded, that consumption of yucca can suppress female reproductive functions.

  20. Preliminary hydrogeologic assessment of boreholes UE-25c No. 1, UE-25c No. 2, and UE-25c No. 3, Yucca Mountain, Nye County, Nevada; Water-resources investigations report 92-4016

    Energy Technology Data Exchange (ETDEWEB)

    Geldon, A.L.

    1993-12-31

    The purpose of this report is to characterize the hydrogeology of saturated tuffaceous rocks penetrated by boreholes UE-25c No. 1, UE-25c No.2, and UE-25c No. 3. These boreholes are referred to collectively in this report as the C-holes. The C-holes were drilled to perform multiwell aquifer tests and tracer tests; they comprise the only complex of closely spaced boreholes completed in the saturated zone at Yucca Mountain. Results of lithologic and geophysical logging, fracture analyses, water-level monitoring, temperature and tracejector surveys, aquifer tests, and hydrochemical sampling completed at the C-hole complex as of 1986 are assessed with respect to the regional geologic and hydrologic setting. A conceptual hydrogeological model of the Yucca Mountain area is presented to provide a context for quantitatively evaluating hydrologic tests performed at the C-hole complex as of 1985, for planning and interpreting additional hydrologic tests at the C-hole complex, and for possibly re-evaluating hydrologic tests in boreholes other than the C-holes.

  1. Where is the hot rock and where is the ground water – Using CSAMT to map beneath and around Mount St. Helens

    Science.gov (United States)

    Wynn, Jeff; Mosbrucker, Adam; Pierce, Herbert; Spicer, Kurt R.

    2016-01-01

    We have observed several new features in recent controlled-source audio-frequency magnetotelluric (CSAMT) soundings on and around Mount St. Helens, Washington State, USA. We have identified the approximate location of a strong electrical conductor at the edges of and beneath the 2004–08 dome. We interpret this conductor to be hot brine at the hot-intrusive-cold-rock interface. This contact can be found within 50 meters of the receiver station on Spine 5, which extruded between April and July of 2005. We have also mapped separate regional and glacier-dome aquifers, which lie one atop the other, out to considerable distances from the volcano.

  2. Geohydrology and quality of water in aquifers in Lucas, Sandusky, and Wood counties, northwestern Ohio

    Science.gov (United States)

    Breen, K.J.; Dumouchelle, D.H.

    1991-01-01

    The hydrology and quality of ground water were evaluated for the surficial sand and carbonate aquifers in northwestern Ohio. A locally important surficial sand aquifer in western Lucas County was evaluated on the basis of data from 10 wells completed in undeveloped and developed areas. The carbonate aquifer in Silurian and Devonian bedrock at its northernmost extent on the Ohio mainland was evaluated on the basis of data from previous studies and data from 466 wells and 11 springs. Most data are for the period 1985-88. The unconfined surficial sand aquifer is less than 50 ft. (feet) thick. Clay-rich drift, which restricts vertical movement of water, underlines the aquifer. Recharge is from precipitation, and discharge is by evapotranspiration and by flow to local streams and drainage ditches. Water levels are generally 2 to 8 ft. below land surface and fluctuate a total of about 3.5 ft. seasonally in a forested area. Concentrations of iron and manganese in ground water are excessive in some areas. Waters from shallow drive-point wells in residential areas contained larger concentrations of dissolved solids, hardness, sodium, and chloride than did waters from identical wells in undeveloped areas. The presence of nitrate nitrogen an other selected constituents in ground water in residential areas, and the absence of these constituents in ground water in undeveloped areas, indicate that the surficial sand aquifer has been affected by development. In carbonate aquifer, fractures, bedding-plane joints, and other secondary openings are the principal water-bearing zones. These zones can be areally and stratigraphically separated by low-permeability rock. Leaky artesian or semiconfined conditions predominate beneath most of the 1,400-mi? study area. The aquifer is confined by relatively impermeable underlying shale of Silurian age and overlying clay-rich drift of Quaternary age. Unproductive strata, including evaporites, within the sequence of carbonate rocks also confine

  3. Aquifer recharge and contamination determination using environmental isotopes: Santiago basin, Chile: A study case

    International Nuclear Information System (INIS)

    Progressive water level descends and nitrate and sulfate contamination have been recorded in Santiago Nor te aquifer since the last decade. This aquifer is almost completely covered by Santiago City which uses groundwater for drinking water, industrial, and commercial uses. Due to the semi-arid conditions of the area and the constant drought periods, groundwater constitutes an extremely important water resource. The accelerated urban growth of Santiago City over the past 30 years has produced impacts on the hydrological cycle and in the degradation of water quality. The impact may be related to the proportion and quality of groundwater recharge induced by urban activities. The study addresses the impact in quality and quantity that urban recharge has in the aquifer beneath the city. In terms of water management, the evaluation of the urban recharge with respect to natural recharge and the determination of the sources of contamination were the main goals of the study. The main results show that the most important natural recharge is associated to the coarse grain facies of the alluvial fan apex of Mapocho River and the local watersheds. The isotopic data shows a minor recharge from direct precipitation over the city. Toward the central sector of the study area, where the oldest part of the city is located and where highly permeable sandy gravel facies over an unconfined aquifer are present, an important source of recharge related to leakage from the drinking water and sewage systems was identified These leaking systems are mainly fed by imported water from another watershed located south of the study area. The distinctive chemical and isotopic signature of this source allows the evaluation of its impact in this area. The remediation of the aquifer will require the reduction of leakages of the water and sewage distribution systems. However, this solution may strongly affect the water balance in the aquifer. (author)

  4. A quantitative analysis of hydraulic interaction processes in stream-aquifer systems

    Science.gov (United States)

    Wang, Wenke; Dai, Zhenxue; Zhao, Yaqian; Li, Junting; Duan, Lei; Wang, Zhoufeng; Zhu, Lin

    2016-01-01

    The hydraulic relationship between the stream and aquifer can be altered from hydraulic connection to disconnection when the pumping rate exceeds the maximum seepage flux of the streambed. This study proposes to quantitatively analyze the physical processes of stream-aquifer systems from connection to disconnection. A free water table equation is adopted to clarify under what conditions a stream starts to separate hydraulically from an aquifer. Both the theoretical analysis and laboratory tests have demonstrated that the hydraulic connectedness of the stream-aquifer system can reach a critical disconnection state when the horizontal hydraulic gradient at the free water surface is equal to zero and the vertical is equal to 1. A boundary-value problem for movement of the critical point of disconnection is established for an analytical solution of the inverted water table movement beneath the stream. The result indicates that the maximum distance or thickness of the inverted water table is equal to the water depth in the stream, and at a steady state of disconnection, the maximum hydraulic gradient at the streambed center is 2. This study helps us to understand the hydraulic phenomena of water flow near streams and accurately assess surface water and groundwater resources.

  5. A quantitative analysis of hydraulic interaction processes in stream-aquifer systems.

    Science.gov (United States)

    Wang, Wenke; Dai, Zhenxue; Zhao, Yaqian; Li, Junting; Duan, Lei; Wang, Zhoufeng; Zhu, Lin

    2016-01-28

    The hydraulic relationship between the stream and aquifer can be altered from hydraulic connection to disconnection when the pumping rate exceeds the maximum seepage flux of the streambed. This study proposes to quantitatively analyze the physical processes of stream-aquifer systems from connection to disconnection. A free water table equation is adopted to clarify under what conditions a stream starts to separate hydraulically from an aquifer. Both the theoretical analysis and laboratory tests have demonstrated that the hydraulic connectedness of the stream-aquifer system can reach a critical disconnection state when the horizontal hydraulic gradient at the free water surface is equal to zero and the vertical is equal to 1. A boundary-value problem for movement of the critical point of disconnection is established for an analytical solution of the inverted water table movement beneath the stream. The result indicates that the maximum distance or thickness of the inverted water table is equal to the water depth in the stream, and at a steady state of disconnection, the maximum hydraulic gradient at the streambed center is 2. This study helps us to understand the hydraulic phenomena of water flow near streams and accurately assess surface water and groundwater resources.

  6. Spatial moments for colloid-enhanced radionuclide transport in heterogeneous aquifers

    Science.gov (United States)

    Severino, Gerardo; Cvetkovic, Vladimir; Coppola, Antonio

    2007-01-01

    We consider colloid facilitated radionuclide transport by steady groundwater flow in a heterogeneous porous formation. Radionuclide binding on colloids and soil-matrix is assumed to be kinetically/equilibrium controlled. All reactive parameters are regarded as uniform, whereas the hydraulic log-conductivity is modelled as a stationary random space function (RSF). Colloid-enhanced radionuclide transport is studied by means of spatial moments pertaining to both the dissolved and colloid-bounded concentration. The general expressions of spatial moments for a colloid-bounded plume are presented for the first time, and are discussed in order to show the combined impact of sorption processes as well as aquifer heterogeneity upon the plume migration. For the general case, spatial moments are defined by the aid of two characteristic reaction functions which cannot be expressed analytically. By adopting the approximation for the longitudinal fluid trajectory covariance valid for a flow parallel to the formation bedding suggested by Dagan and Cvetkovic [Dagan G, Cvetkovic V. Spatial Moments of Kinetically Sorbing Plume in a Heterogeneous Aquifers. Water Resour Res 1993;29:4053], we obtain closed form solutions. For illustrative purposes, we consider the case when sorption/desorption between solution and moving colloids is a linear non-equilibrium process, whereas sorption onto the soil-matrix is a linear equilibrium process. Based on the flow and transport parameters pertaining to the alluvial aquifer at the Yucca Mountain Site (Nevada), we investigate the potential enhancing role of colloidal particles by comparing radionuclide spatial moments with and without colloids, and mainly investigate the sensitivity to the reverse rate parameter. The most potentially significant effects are obtained when radionuclide attachment to colloidal particles is irreversible. The simplicity of our results makes them suitable for quick assessments of the potential impact of colloids on

  7. Paleohydrology of the southern Great Basin, with special reference to water table fluctuations beneath the Nevada Test Site during the late(?) Pleistocene

    Science.gov (United States)

    Winograd, Isaac Judah; Doty, Gene C.

    1980-01-01

    Knowledge of the magnitude of water-table rise during Pleistocene pluvial climates, and of the resultant shortening of groundwater flow path and reduction in unsaturated zone thickness, is mandatory for a technical evaluation of the Nevada Test Site (NTS) or other arid zone sites as repositories for high-level or transuranic radioactive wastes. The distribution of calcitic veins filling fractures in alluvium, and of tufa deposits between the Ash Meadows spring discharge area and the Nevada Test Site indicates that discharge from the regional Paleozoic carbonate aquifer during the Late( ) Pleistocene pluvial periods may have occurred at an altitude about 50 meters higher than at present and 14 kilometers northeast of Ash Meadows. Use of the underflow equation (relating discharge to transmissivity, aquifer width, and hydraulic gradient), and various assumptions regarding pluvial recharge, transmissivity, and altitude of groundwater base level, suggest possible rises in potentiometric level in the carbonate aquifer of about -90 meters beneath central Frenchman Flat. During Wisconsin time the rise probably did not exceed 30 meters. Water-level rises beneath Frenchman Flat during future pluvials are unlikely to exceed 30 meters and might even be 10 meters lower than modern levels. Neither the cited rise in potentiometric level in the regional carbonate aquifer, nor the shortened flow path during the Late( ) Pleistocene preclude utilization of the NTS as a repository for high-level or transuranic-element radioactive wastes provided other requisite conditions are met as this site. Deep water tables, attendant thick (up to several hundred meter) unsaturated zones, and long groundwater flow paths characterized the region during the Wisconsin Stage and probably throughout the Pleistocene Epoch and are likely to so characterize it during future glacial periods. (USGS)

  8. 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

  9. 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.

  10. EFFECTS OF YUCCA SHIDIGERA EXTRACT ON THE REDUCTION OF AMMONIA CONCENTRATION IN LAKE KOUMOUNDOUROU

    Directory of Open Access Journals (Sweden)

    Xiaoxi Yu

    2015-09-01

    Full Text Available Nitrogen related water pollution in aquatic systems is one of the most common problems encountered worldwide nowadays. Different restoration practices have been tested to eliminate the impacts from eutrophication but no widely applicable methodology has been found until now. Extract of Yucca shidigera has been proved effective in reducing ammonia in livestock industry and aquaculture but have not been yet tested in freshwater ecosystems. In this study, the effects of yucca extract on the reduction of ammonia in Lake Koumoundourou have been investigated. Yucca extract was added at various concentrations to experimental tanks containing lake water and sediment. The results show that yucca extract significantly reduced the concentration of ammonia while other water quality parameters were relatively stable during the experiment, except from dissolved oxygen. The study indicates that yucca extract as a restoration method can be promising but larger scale experiments should be conducted to validate this outcome.

  11. 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

  12. Aquifer Characteristics Data Report for the Weldon Spring Site chemical plant/raffinate pits and vicinity properties for the Weldon Spring Site Remedial Action Project, Weldon Spring, Missouri

    Energy Technology Data Exchange (ETDEWEB)

    1990-11-01

    This report describes the procedures and methods used, and presents the results of physical testing performed, to characterize the hydraulic properties of the shallow Mississippian-Devonian aquifer beneath the Weldon Spring chemical plant, raffinate pits, and vicinity properties. The aquifer of concern is composed of saturated rocks of the Burlington-Keokuk Limestone which constitutes the upper portion of the Mississippian-Devonian aquifer. This aquifer is a heterogeneous anisotropic medium which can be described in terms of diffuse Darcian flow overlain by high porosity discrete flow zones and conduits. Average hydraulic conductivity for all wells tested is 9.6E-02 meters/day (3.1E-01 feet/day). High hydraulic conductivity values are representative of discrete flow in the fractured and weathered zones in the upper Burlington-Keokuk Limestone. They indicate heterogeneities within the Mississippian-Devonian aquifer. Aquifer heterogeneity in the horizontal plane is believed to be randomly distributed and is a function of fracture spacing, solution voids, and preglacial weathering phenomena. Relatively high hydraulic conductivities in deeper portions of the aquifer are though to be due to the presence of widely spaced fractures. 44 refs., 27 figs., 9 tabs.

  13. Simulation of Groundwater Flow in the Coastal Plain Aquifer System of Virginia

    Science.gov (United States)

    Heywood, Charles E.; Pope, Jason P.

    2009-01-01

    The groundwater model documented in this report simulates the transient evolution of water levels in the aquifers and confining units of the Virginia Coastal Plain and adjacent portions of Maryland and North Carolina since 1890. Groundwater withdrawals have lowered water levels in Virginia Coastal Plain aquifers and have resulted in drawdown in the Potomac aquifer exceeding 200 feet in some areas. The discovery of the Chesapeake Bay impact crater and a revised conceptualization of the Potomac aquifer are two major changes to the hydrogeologic framework that have been incorporated into the groundwater model. The spatial scale of the model was selected on the basis of the primary function of the model of assessing the regional water-level responses of the confined aquifers beneath the Coastal Plain. The local horizontal groundwater flow through the surficial aquifer is not intended to be accurately simulated. Representation of recharge, evapotranspiration, and interaction with surface-water features, such as major rivers, lakes, the Chesapeake Bay, and the Atlantic Ocean, enable simulation of shallow flow-system details that influence locations of recharge to and discharge from the deeper confined flow system. The increased density of groundwater associated with the transition from fresh to salty groundwater near the Atlantic Ocean affects regional groundwater flow and was simulated with the Variable Density Flow Process of SEAWAT (a U.S. Geological Survey program for simulation of three-dimensional variable-density groundwater flow and transport). The groundwater density distribution was generated by a separate 108,000-year simulation of Pleistocene freshwater flushing around the Chesapeake Bay impact crater during transient sea-level changes. Specified-flux boundaries simulate increasing groundwater underflow out of the model domain into Maryland and minor underflow from the Piedmont Province into the model domain. Reported withdrawals accounted for approximately

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. 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.

  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. 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

  2. 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

  3. 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:

  4. 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.

  5. Mantle discontinuities beneath Izu-Bonin and the implications

    Institute of Scientific and Technical Information of China (English)

    臧绍先; 周元泽; 蒋志勇

    2003-01-01

    The SdP, pdP and sdP phases are picked up with the Nth root slant stack method from the digital waveform data recorded by the networks and arrays in USA, Germany and Switzerland for the earthquakes occurring beneath Izu-Bonin and Japan Sea. The mantle discontinuities and the effects of subducting slab on the 660 km and 410 km discontinuities are studied. It is found that there are mantle discontinuities existing at the depths of 170, 220, 300, 410, 660, 850 and 1150 km. Beneath Izu-Bonin, the 410 km discontinuity is elevated, while the 660 km discontinuity is depressed; for both discontinuities, there are regionalized differences. Beneath Japan Sea, however, there is no depth variation of the 410 km discontinuity, and the 660 km discontinuity is depressed without obvious effect of the subducting slab.

  6. Initiation of liquid-solid contact beneath an impacting drop

    Science.gov (United States)

    Rubinstein, Shmuel; Kolinski, John

    2015-11-01

    Before an impacting drop contacts the solid surface it must first drain the air beneath it. As a prelude to wetting, before any contact occurs, the impinging liquid confines the intervening air into a nanometers-thin film. Once liquid-solid contact initiates by the spontaneous formation of a liquid bridge, the fluid rapidly wicks through the thin film of air, permanently binding the drop to the surface. Here, we experimentally examine these initial stages in the formation of the liquid solid contact beneath the impacting drop. Fast TIR microscopy enables unprecedented spatial and temporal resolution of the wetting process beneath the impacting drop and permits 3-dimensional imaging of the real contact line as well as nanometer-resolution of the thin film of air separating the liquid from the solid.

  7. Hydrologic and water-chemistry data from the Cretaceous-aquifers test well (BFT-2055), Beaufort County, South Carolina

    Science.gov (United States)

    Landmeyer, J.E.; Bradley, P.M.

    1998-01-01

    Test well BFT-2055 was drilled through the entire thickness of Coastal Plain sediments beneath central Hilton Head Island, South Carolina, and terminated in bedrock at a depth of 3833 feet. The well was drilled to evaluate the hydraulic properties of the Cretaceous formations beneath Hilton Head Island as a potential source of supplemental water to supplies currently withdrawn from the Upper Floridan aquifer. The intervals tested include sediments of the Cape Fear and Middendorf Formations. Results from aquifer tests indicate that the transmissivity of the formations screened ranges from 1300 to 3000 feet squared per day and an average hydraulic conductivity of about 15 feet per day. Formation-fluid pressure tests indicate that the potential exists for upward ground-water flow from higher fluid pressures in the deeper Cape Fear and Middendorf Formations to lower fluid pressures in the Black Creek Formation and shallower units. A flowmeter test indicated that greater than 75 percent of the natural, unpumped flow in the well is from the screened intervals no deeper than 3100 feet. Water-chemistry analyses indicate that the water sampled from the Middendorf and Cape Fear has about 1450 milligrams per liter dissolved solids, 310 to 1000 milligrams per liter sodium, and 144 to 1600 milligrams per liter chloride. Because these chloride concentrations would render water pumped from these aquifers as nonpotable, it is unlikely that these aquifers will be used as a supplemental source of water for island residents without some form of pretreatment. Similar chloride concentrations are present in some wells in the Upper Floridan aquifer adjacent to Port Royal Sound, and these chloride concentrations were the primary reason for drilling the test well in the Cretaceous formations as a possible source of more potable water.

  8. Imaging of seismic scatterers beneath the Gauribidanur (GBA) array

    International Nuclear Information System (INIS)

    A study has been conducted to image seismic scatterers beneath the Gauribidanur (GBA) array in the Precambrian shield of south India. Short period digital data from teleseisms and regional events recorded over the 20 station L shaped array was used to image seismic scatterers beneath the array employing semblance technique. The results indicate a zone of dominant scattering encompassing the crust in a region west of GBA. The inferred zone of scattering coincides with a large N-S elongated granitic intrusion believed to be Precambrian suture zone between the East and West Dharwar craton. (author). 16 refs, 7 figs, 1 tab

  9. Seismic imaging of the downwelling Indian lithosphere beneath central Tibet.

    Science.gov (United States)

    Tilmann, Frederik; Ni, James

    2003-05-30

    A tomographic image of the upper mantle beneath central Tibet from INDEPTH data has revealed a subvertical high-velocity zone from approximately 100- to approximately 400-kilometers depth, located approximately south of the Bangong-Nujiang Suture. We interpret this zone to be downwelling Indian mantle lithosphere. This additional lithosphere would account for the total amount of shortening in the Himalayas and Tibet. A consequence of this downwelling would be a deficit of asthenosphere, which should be balanced by an upwelling counterflow, and thus could explain the presence of warm mantle beneath north-central Tibet.

  10. Hammering Yucca Flat, Part Two: Shear-Wave Velocity

    Science.gov (United States)

    Finlay, T. S.; Abbott, R. E.; Knox, H. A.; Tang, D. G.; James, S. R.; Haney, M. M.; Hampshire, J. B., II

    2015-12-01

    In preparation for the next phase of the Source Physics Experiment (SPE), we conducted an active-source seismic survey of Yucca Flat, Nevada, on the Nevada National Security Site. Results from this survey will be used to inform the geologic models associated with the SPE project. For this study, we used a novel 13,000 kilogram weight-drop seismic source to interrogate an 18-km North-South transect of Yucca Flat. Source points were spaced every 200 meters and were recorded by 350 to 380 3-component 2-Hz geophones with variable spacings of 10, 20, and 100 meters. We utilized the Refraction-Microtremor (ReMi) technique to create multiple 1D dispersion curves, which were then inverted for shear-wave velocity profiles using the Dix inversion method (Tsai and Haney, 2015). Each of these 1D velocity models was subsequently stitched together to create a 2D profile over the survey area. The dispersion results indicate a general decrease in surface-wave phase velocity to the south. This result is supported by slower shear-wave velocity sediments and increasing basin depth towards the survey's southern extent. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  11. 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

  12. 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

  13. 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

  14. Considerations in the extraction of uranium from a fresh-water aquifer - Miocene Oakville Sandstone, south Texas

    International Nuclear Information System (INIS)

    The Miocene Oakville Sandstone is a major aquifer and uranium host beneath the Texas Coastal Plain. Present and future uranium mining by either surface or in situ methods could affect the availability and quality of Oakville ground water unless the mining is designed properly. Possible effects of mining, potential natural mitigation of these effects, and approaches to minimizing the impact of mining on the aquifer system are discussed. Both solution and surface mining may affect the availability of ground water by altering recharge characteristics and permeability. Because the volume of the aquifer affected by mining is small compared with its total volume, availability of Oakville ground water will probably not be reduced significantly, except in wells immediately adjacent to a mine. Mining may affect the quality of ground water by introducing chemicals that are not indigenous to the aquifer or by inducing chemical reactions that do not occur naturally or that occur at much slower rates. Most mining companies no longer use concentrated, ammonium-based leaches because of known problems in restoring water to its original chemistry. Natural and induced release of trace elements such as molybdenum is known to occur, but the geochemical controls on mobility and potential mitigating reactions in the aquifer are poorly understood. Because the affected aquifer volume is small, any deterioration of water quality will probably be localized. Observations and recommendations are presented on: regional and local baseline studies, determination of aquifer sensitivity, methods and goals of monitoring during and after mining, and need for research on poorly understood aspects of mining impact. Such impacts include chemical reactions and processes that affect the long-term release of trace elements

  15. 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.

  16. Digital data sets that describe aquifer characteristics of the Enid isolated terrace aquifer in northwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized water-level elevation contours for the Enid isolated terrace aquifer in northwestern Oklahoma. The Enid isolated terrace aquifer...

  17. Digital data sets that describe aquifer characteristics of the Central Oklahoma aquifer in central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized aquifer boundaries created for a previously published report about the Central Oklahoma aquifer in central Oklahoma. This area...

  18. Digital data sets that describe aquifer characteristics of the Elk City aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized polygons of constant recharge values for the Elk City aquifer in western Oklahoma. The aquifer covers an area of approximately...

  19. Digital data sets that describe aquifer characteristics of the High Plains aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital aquifer boundaries for the High Plains aquifer in western Oklahoma. This area encompasses the panhandle counties of Cimarron,...

  20. Digital data sets that describe aquifer characteristics of the Antlers aquifer in southeastern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized aquifer boundaries of the Antlers aquifer in southeastern Oklahoma. The Early Cretaceous-age Antlers Sandstone is an important...

  1. Digital data sets that describe aquifer characteristics of the Rush Springs aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized aquifer boundaries for the Rush Springs aquifer in western Oklahoma. This area encompasses all or part of Blaine, Caddo,...

  2. Digital data sets that describe aquifer characteristics of the Elk City aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized water-level elevation contours for the Elk City aquifer in western Oklahoma. The aquifer covers an area of approximately 193,000...

  3. Digital data sets that describe aquifer characteristics of the Elk City aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized polygons of constant hydraulic conductivity values for the Elk City aquifer in western Oklahoma. The aquifer covers an area of...

  4. 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.

  5. 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

  6. Hydrogeology of the unsaturated zone, North Ramp area of the Exploratory Studies Facility, Yucca Mountain, Nevada

    Science.gov (United States)

    Rousseau, Joseph P.; Kwicklis, Edward M.; Gillies, Daniel C.; Rousseau, Joseph P.; Kwicklis, Edward M.; Gillies, Daniel C.

    1999-01-01

    Yucca Mountain, in southern Nevada, is being investigated by the U.S. Department of Energy as a potential site for a repository for high-level radioactive waste. This report documents the results of surface-based geologic, pneumatic, hydrologic, and geochemical studies conducted during 1992 to 1996 by the U.S. Geological Survey in the vicinity of the North Ramp of the Exploratory Studies Facility (ESF) that are pertinent to understanding multiphase fluid flow within the deep unsaturated zone. Detailed stratigraphic and structural characteristics of the study area provided the hydrogeologic framework for these investigations. Multiple lines of evidence indicate that gas flow and liquid flow within the welded tuffs of the unsaturated zone occur primarily through fractures. Fracture densities are highest in the Tiva Canyon welded (TCw) and Topopah Spring welded (TSw) hydrogeologic units. Although fracture density is much lower in the intervening nonwelded and bedded tuffs of the Paintbrush nonwelded hydrogeologic unit (PTn), pneumatic and aqueous-phase isotopic evidence indicates that substantial secondary permeability is present locally in the PTn, especially in the vicinity of faults. Borehole air-injection tests indicate that bulk air-permeability ranges from 3.5x10-14 to 5.4x10-11 square meters for the welded tuffs and from 1.2x10-13 to 3.0x10-12 square meters for the non welded and bedded tuffs of the PTn. Analyses of in-situ pneumatic-pressure data from monitored boreholes produced estimates of bulk permeability that were comparable to those determined from the air-injection tests. In many cases, both sets of estimates are two to three orders of magnitude larger than estimates based on laboratory analyses of unfractured core samples. The in-situ pneumatic-pressure records also indicate that the unsaturated-zone pneumatic system consists of four subsystems that coincide with the four major hydrogeologic units of the unsaturated zone at Yucca Mountain. In

  7. Groundwater evolution beneath Hat Yai, a rapidly developing city in Thailand

    Science.gov (United States)

    Lawrence, A. R.; Gooddy, D. C.; Kanatharana, P.; Meesilp, W.; Ramnarong, V.

    2000-09-01

    Many cities and towns in South and Southeast Asia are unsewered, and urban wastewaters are often discharged either directly to the ground or to surface-water canals and channels. This practice can result in widespread contamination of the shallow groundwater. In Hat Yai, southern Thailand, seepage of urban wastewaters has produced substantial deterioration in the quality of the shallow groundwater directly beneath the city. For this reason, the majority of the potable water supply is obtained from groundwater in deeper semi-confined aquifers 30-50 m below the surface. However, downward leakage of shallow groundwater from beneath the city is a significant component of recharge to the deeper aquifer, which has long-term implications for water quality. Results from cored boreholes and shallow nested piezometers are presented. The combination of high organic content of the urban recharge and the shallow depth to the water table has produced strongly reducing conditions in the upper layer and the mobilisation of arsenic. A simple analytical model shows that time scales for downward leakage, from the surface through the upper aquitard to the semi-confined aquifer, are of the order of several decades. Résumé. De nombreuses villes du sud et du sud-est de l'Asie ne possèdent pas de réseaux d'égouts et les eaux usées domestiques s'écoulent souvent directement sur le sol ou dans des canaux et des cours d'eau de surface. Ces pratiques peuvent provoquer une contamination dispersée de la nappe phréatique. A Hat Yai (sud de la Thaïlande), les infiltrations d'eaux usées domestiques sont responsables d'une détérioration notable de la qualité de la nappe phréatique directement sous la ville. Pour cette raison, la majorité de l'eau potable est prélevée dans des aquifères semi-captifs plus profonds, situés entre 30 et 50 m sous la surface. Cependant, une drainance à partir de la nappe phréatique sous la ville constitue une composante significative de la recharge

  8. Deep long-period earthquakes beneath Washington and Oregon volcanoes

    Science.gov (United States)

    Nichols, M.L.; Malone, S.D.; Moran, S.C.; Thelen, W.A.; Vidale, J.E.

    2011-01-01

    Deep long-period (DLP) earthquakes are an enigmatic type of seismicity occurring near or beneath volcanoes. They are commonly associated with the presence of magma, and found in some cases to correlate with eruptive activity. To more thoroughly understand and characterize DLP occurrence near volcanoes in Washington and Oregon, we systematically searched the Pacific Northwest Seismic Network (PNSN) triggered earthquake catalog for DLPs occurring between 1980 (when PNSN began collecting digital data) and October 2009. Through our analysis we identified 60 DLPs beneath six Cascade volcanic centers. No DLPs were associated with volcanic activity, including the 1980-1986 and 2004-2008 eruptions at Mount St. Helens. More than half of the events occurred near Mount Baker, where the background flux of magmatic gases is greatest among Washington and Oregon volcanoes. The six volcanoes with DLPs (counts in parentheses) are Mount Baker (31), Glacier Peak (9), Mount Rainier (9), Mount St. Helens (9), Three Sisters (1), and Crater Lake (1). No DLPs were identified beneath Mount Adams, Mount Hood, Mount Jefferson, or Newberry Volcano, although (except at Hood) that may be due in part to poorer network coverage. In cases where the DLPs do not occur directly beneath the volcanic edifice, the locations coincide with large structural faults that extend into the deep crust. Our observations suggest the occurrence of DLPs in these areas could represent fluid and/or magma transport along pre-existing tectonic structures in the middle crust. ?? 2010 Elsevier B.V.

  9. Subduction of the Indian Lithospheric Slab Beneath Tibet

    Science.gov (United States)

    Zhou, H.; Murphy, M. A.

    2001-12-01

    In order to characterize the dynamics of continent-continent collisions, it is essential to define its present geometry and physical state. We report the results of a seismic tomography study of the Tibet-Himalayan collision zone, using a global data set, which indicates that the Indian lithospheric slab has been subducted subhorizontally beneath nearly the entire Tibetan plateau to depths of 165-260 km. Tibetan velocity structure is low in the crust and high in mantle lithosphere at depths between 75-120 km. An asthenospheric layer overlies the subducted Indian slab at depths between 120-165 km beneath the Tibetan plateau. There is a large low-velocity anomaly north of the Indus-Yalu suture zone between 85ºE and 93ºE that extends from the crust down to at least 310 km depth beneath the plateau. This low-velocity anomaly is indicative of mantle upwelling through a weakened zone of the subducted slab. The extent to which India has subducted beneath Tibet, as revealed by these seismic images, is comparable to estimates of crustal shortening across the Himalaya. Moreover, we hypothesize that the buoyancy due to heating of the subducted Indian slab and the existence of the asthenospheric layer contribute to the elevation and flatness of the Tibetan plateau.

  10. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-05-01

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

  12. 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.``

  13. Groundwater Remediation in a Floodplain Aquifer at Shiprock, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Dave [Navarro Research and Engineering; Miller, David [Navarro Research and Engineering; Kautsky, Mark [U. S. Department of Energy, Office of Legacy Management; Dander, David [Navarro Research and Engineering; Nofchissey, Joni [Navajo Nation Division of Natural Resources

    2016-03-06

    A uranium- and vanadium-ore-processing mill operated from 1954 to 1968 within the Navajo Nation near Shiprock, New Mexico. By September 1986, all tailings and structures on the former mill property were encapsulated in a disposal cell built on top of two existing tailings piles on the Shiprock site (the site) [1]. Local groundwater was contaminated by multiple inorganic constituents as a result of the milling operations. The U.S. Department of Energy (DOE) took over management of the site in 1978 as part of the Uranium Mill Tailings Remedial Action (UMTRA) Project. The DOE Office of Legacy Management currently manages ongoing activities at the former mill facility, including groundwater remediation. Remediation activities are designed primarily to reduce the concentrations and total plume mass of the mill-related contaminants sulfate, uranium, and nitrate. In addition to contaminating groundwater in alluvial and bedrock sediments directly below the mill site, ore processing led to contamination of a nearby floodplain bordering the San Juan River. Groundwater in a shallow alluvial aquifer beneath the floodplain is strongly influenced by the morphology of the river channel as well as changing flows in the river, which provides drainage for regional runoff from the San Juan Mountains of Colorado. As part of a recent study of the floodplain hydrology, a revised conceptual model was developed for the alluvial aquifer along with an updated status of contaminant plumes that have been impacted by more than 10 years of groundwater pumping for site remediation purposes. Several findings from the recent study will be discussed here.

  14. Modelling the Crust beneath the Kashmir valley in Northwestern Himalaya

    Science.gov (United States)

    Mir, R. R.; Parvez, I. A.; Gaur, V. K.; A.; Chandra, R.; Romshoo, S. A.

    2015-12-01

    We investigate the crustal structure beneath five broadband seismic stations in the NW-SE trendingoval shaped Kashmir valley sandwiched between the Zanskar and the Pir Panjal ranges of thenorthwestern Himalaya. Three of these sites were located along the southwestern edge of the valley andthe other two adjoined the southeastern. Receiver Functions (RFs) at these sites were calculated usingthe iterative time domain deconvolution method and jointly inverted with surface wave dispersiondata to estimate the shear wave velocity structure beneath each station. To further test the results ofinversion, we applied forward modelling by dividing the crust beneath each station into 4-6homogeneous, isotropic layers. Moho depths were separately calculated at different piercing pointsfrom the inversion of only a few stacked receiver functions of high quality around each piercing point.These uncertainties were further reduced to ±2 km by trial forward modelling as Moho depths werevaried over a range of ±6 km in steps of 2 km and the synthetic receiver functions matched with theinverted ones. The final values were also found to be close to those independently estimated using theH-K stacks. The Moho depths on the eastern edge of the valley and at piercing points in itssouthwestern half are close to 55 km, but increase to about 58 km on the eastern edge, suggesting thathere, as in the central and Nepal Himalaya, the Indian plate dips northeastwards beneath the Himalaya.We also calculated the Vp/Vs ratio beneath these 5 stations which were found to lie between 1.7 and1.76, yielding a Poisson's ratio of ~0.25 which is characteristic of a felsic composition.

  15. Crustal structure beneath northeast India inferred from receiver function modeling

    Science.gov (United States)

    Borah, Kajaljyoti; Bora, Dipok K.; Goyal, Ayush; Kumar, Raju

    2016-09-01

    We estimated crustal shear velocity structure beneath ten broadband seismic stations of northeast India, by using H-Vp/Vs stacking method and a non-linear direct search approach, Neighbourhood Algorithm (NA) technique followed by joint inversion of Rayleigh wave group velocity and receiver function, calculated from teleseismic earthquakes data. Results show significant variations of thickness, shear velocities (Vs) and Vp/Vs ratio in the crust of the study region. The inverted shear wave velocity models show crustal thickness variations of 32-36 km in Shillong Plateau (North), 36-40 in Assam Valley and ∼44 km in Lesser Himalaya (South). Average Vp/Vs ratio in Shillong Plateau is less (1.73-1.77) compared to Assam Valley and Lesser Himalaya (∼1.80). Average crustal shear velocity beneath the study region varies from 3.4 to 3.5 km/s. Sediment structure beneath Shillong Plateau and Assam Valley shows 1-2 km thick sediment layer with low Vs (2.5-2.9 km/s) and high Vp/Vs ratio (1.8-2.1), while it is observed to be of greater thickness (4 km) with similar Vs and high Vp/Vs (∼2.5) in RUP (Lesser Himalaya). Both Shillong Plateau and Assam Valley show thick upper and middle crust (10-20 km), and thin (4-9 km) lower crust. Average Vp/Vs ratio in Assam Valley and Shillong Plateau suggest that the crust is felsic-to-intermediate and intermediate-to-mafic beneath Shillong Plateau and Assam Valley, respectively. Results show that lower crust rocks beneath the Shillong Plateau and Assam Valley lies between mafic granulite and mafic garnet granulite.

  16. Hot mantle upwelling across the 660 beneath Yellowstone

    Science.gov (United States)

    Schmandt, Brandon; Dueker, Kenneth; Humphreys, Eugene; Hansen, Steven

    2012-05-01

    P-to-s receiver functions mapped to depth through P and S body-wave tomography models image continuous 410 and 660 km discontinuities beneath the area covered by USArray prior to the year 2011. Mean depths to the 410 and 660 km discontinuities of 410 and 656 km imply a mantle transition zone that is about 4 km thicker than the global average and hence has a slightly cooler mean temperature and/or enhanced water content. Compared to the mean 660 depth beneath this ~ 2000 km wide area, the 660 beneath the Yellowstone hotspot is deflected upward by 12-18 km over an area about 200 km wide. This is the most anomalous shallowing of the 660 imaged and its horizontal extent is similar to the area where P and S tomography image low-velocity mantle extending from the top of the transition zone to about 900 km depth. Together, these results indicate a high-temperature, plume-like upwelling extending across the 660. The depth of 410 km discontinuity beneath the Yellowstone region is within 5 km of the mean depth implying that the plume is vertically heterogeneous and possibly discontinuous. Tomography indicates a similar vertically heterogeneous thermal plume. The irregular plume structure may be intrinsic to the dynamics of upwelling through the transition zone, or distortion may be caused by subduction-induced mantle flow. Topography of the 410 and 660 confirms that subducted slabs beneath the western U.S. are highly segmented, as inferred from recent tomography studies. We find no evidence of regionally pervasive velocity discontinuities between 750 and 1400 km depth. The plume's depth of origin within the lower mantle remains uncertain.

  17. Relationships between microbial community structure and hydrochemistry in a landfill leachate-polluted aquifer.

    Science.gov (United States)

    Röling, W F; van Breukelen, B M; Braster, M; Lin, B; van Verseveld, H W

    2001-10-01

    Knowledge about the relationship between microbial community structure and hydrogeochemistry (e.g., pollution, redox and degradation processes) in landfill leachate-polluted aquifers is required to develop tools for predicting and monitoring natural attenuation. In this study analyses of pollutant and redox chemistry were conducted in parallel with culture-independent profiling of microbial communities present in a well-defined aquifer (Banisveld, The Netherlands). Degradation of organic contaminants occurred under iron-reducing conditions in the plume of pollution, while upstream of the landfill and above the plume denitrification was the dominant redox process. Beneath the plume iron reduction occurred. Numerical comparison of 16S ribosomal DNA (rDNA)-based denaturing gradient gel electrophoresis (DGGE) profiles of Bacteria and Archaea in 29 groundwater samples revealed a clear difference between the microbial community structures inside and outside the contaminant plume. A similar relationship was not evident in sediment samples. DGGE data were supported by sequencing cloned 16S rDNA. Upstream of the landfill members of the beta subclass of the class Proteobacteria (beta-proteobacteria) dominated. This group was not encountered beneath the landfill, where gram-positive bacteria dominated. Further downstream the contribution of gram-positive bacteria to the clone library decreased, while the contribution of delta-proteobacteria strongly increased and beta-proteobacteria reappeared. The beta-proteobacteria (Acidovorax, Rhodoferax) differed considerably from those found upstream (Gallionella, Azoarcus). Direct comparisons of cloned 16S rDNA with bands in DGGE profiles revealed that the data from each analysis were comparable. A relationship was observed between the dominant redox processes and the bacteria identified. In the iron-reducing plume members of the family Geobacteraceae made a strong contribution to the microbial communities. Because the only known

  18. 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

  19. 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

  20. 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.

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

    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 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.

  2. 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

  3. 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

  4. 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.

  5. 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

  6. Digital data sets that describe aquifer characteristics of the Tillman terrace and alluvial aquifer in southwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital aquifer boundaries for the Tillman terrace and alluvial aquifer in southwestern Oklahoma. The Tillman terrace aquifer encompasses...

  7. Digital data sets that describe aquifer characteristics of the Vamoosa-Ada aquifer in east-central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized aquifer boundaries for the Vamoosa-Ada aquifer in east-central Oklahoma. The Vamoosa-Ada aquifer is an important source of water...

  8. Chlorine isotope investigation of natural attenuation of trichloroethene in an aerobic aquifer

    International Nuclear Information System (INIS)

    Natural attenuation of chlorinated aliphatic hydrocarbons (CAHs) can be an important mechanism for groundwater remediation. It is difficult to determine the effectiveness of natural CAH attenuation from chemical analyses of groundwater samples because mixing, dispersion, and secondary reactions can mask the chemical evidence of attenuation. In this paper, the authors explore the application of stable chlorine isotope ratio measurements as a new tool for evaluating natural attenuation of CAHs. They report stable isotope ratios of chlorine in both trichloroethene (TCE) and inorganic chloride in groundwater from an aerobic aquifer beneath an extensively contaminated industrial site, the Paducah Gaseous Diffusion Plant in western Kentucky. Variations in the concentrations and chlorine isotope ratios of TCE and chloride in the groundwater are consistent with those expected from natural attenuation. These data support a model in which partial TCE degradation occurred in relatively impermeable, clay-rich sediments above the aquifer, and little or no further degradation of TCE occurred within the aquifer. A record of changing conditions within the TCE source area can be inferred from the spatial variation of chlorine isotope ratios for TCE and chloride within the plume

  9. Recharge beneath low-impact design rain gardens and the influence of El Niño Southern Oscillation on urban, coastal groundwater resources

    Science.gov (United States)

    Newcomer, M. E.; Gurdak, J. J.

    2011-12-01

    Groundwater resources in urban, coastal environments are highly vulnerable to increased human pressures and climate variability. Impervious surfaces, such as buildings, roads, and parking lots prevent infiltration, reduce recharge to underlying aquifers, and increase contaminants in surface runoff that often overflow sewage systems. To mitigate these effects, cities worldwide are adopting low impact design (LID) approaches that direct runoff into natural vegetated systems, such as rain gardens that reduce, filter, and slow stormwater runoff, and are hypothesized to increase infiltration and recharge rates to aquifers. The effects of LID on recharge rates and quality is unknown, particularly during intense precipitation events for cities along the Pacific coast in response to interannual variability of the El Niño Southern Oscillation (ENSO). Using vadose zone monitoring sensors and instruments, I collected and monitored soil, hydraulic, and geochemical data to quantify the rates and quality of infiltration and recharge to the California Coastal aquifer system beneath a LID rain garden and traditional turf-lawn setting in San Francisco, CA. The data were used to calibrate a HYDRUS-3D model to simulate recharge rates under historical and future variability of ENSO. Understanding these processes has important implications for managing groundwater resources in urban, coastal environments.

  10. 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

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. 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

  19. 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

  20. 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.

  1. The saturated zone at Yucca Mountain: an overview of the characterization and assessment of the saturated zone as a barrier to potential radionuclide migration.

    Science.gov (United States)

    Eddebbarh, A A; Zyvoloski, G A; Robinson, B A; Kwicklis, E M; Reimus, P W; Arnold, B W; Corbet, T; Kuzio, S P; Faunt, C

    2003-01-01

    The US Department of Energy is pursuing Yucca Mountain, Nevada, for the development of a geologic repository for the disposal of spent nuclear fuel and high-level radioactive waste, if the repository is able to meet applicable radiation protection standards established by the US Nuclear Regulatory Commission and the US Environmental Protection Agency (EPA). Effective performance of such a repository would rely on a number of natural and engineered barriers to isolate radioactive waste from the accessible environment. Groundwater beneath Yucca Mountain is the primary medium through which most radionuclides might move away from the potential repository. The saturated zone (SZ) system is expected to act as a natural barrier to this possible movement of radionuclides both by delaying their transport and by reducing their concentration before they reach the accessible environment. Information obtained from Yucca Mountain Site Characterization Project activities is used to estimate groundwater flow rates through the site-scale SZ flow and transport model area and to constrain general conceptual models of groundwater flow in the site-scale area. The site-scale conceptual model is a synthesis of what is known about flow and transport processes at the scale required for total system performance assessment of the site. This knowledge builds on and is consistent with knowledge that has accumulated at the regional scale but is more detailed because more data are available at the site-scale level. The mathematical basis of the site-scale model and the associated numerical approaches are designed to assist in quantifying the uncertainty in the permeability of rocks in the geologic framework model and to represent accurately the flow and transport processes included in the site-scale conceptual model. Confidence in the results of the mathematical model was obtained by comparing calculated to observed hydraulic heads, estimated to measured permeabilities, and lateral flow rates

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

    Energy Technology Data Exchange (ETDEWEB)

    Keiser, D.D.

    1996-11-01

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

  3. 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.

  4. 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

  5. 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

  6. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    none,

    1998-12-01

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

  8. 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.

  9. 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.

  10. 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

  11. VULNERABILITY OF KARST AQUIFERS TO CHEMICAL CONTAMINATION

    Science.gov (United States)

    Ground water flow in karst aquifers is very different from flow in granular or fractured aquifers. arst ground water flow is often turbulent within discrete conduits that are convergent in the upper reaches and divergent in the lower, simulating discharge to one or more springs. ...

  12. Geohydrology of the Cerro Prieto geothermal aquifer

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez R, J.; de la Pena L, A.

    1981-01-01

    The most recent information on the Cerro Prieto geothermal aquifer is summarized, with special emphasis on the initial production zone where the wells completed in the Alpha aquifer are located. These wells produce steam for power plant units 1 and 2. Brief comments also are made on the Beta aquifer, which underlies the Alpha aquifer in the Cerro Prieto I area and which extends to the east to what is known as the Cerro Prieto II and Cerro Prieto III areas. The location of the area studied is shown. The Alpha and Beta aquifers differ in their mineralogy and cementing mineral composition, temperatures, and piezometric levels. The difference in piezometric levels indicates that there is no local communication between the two aquifers. This situation has been verified by a well interference test, using well E-1 as a producer in the Beta aquifer and well M-46 as the observation well in the Alpha aquifer. No interference between them was observed. Information on the geology, geohydrology, and geochemistry of Cerro Prieto is presented.

  13. Hydrology of the unsaturated zone, Yucca Mountain, Nevada

    Science.gov (United States)

    LeCain, Gary D.; Stuckless, John S.

    2012-01-01

    The unsaturated zone at Yucca Mountain was investigated as a possible site for the nation's first high-level nuclear waste repository. Scientific investigations included infiltration studies, matrix properties testing, borehole testing and monitoring, underground excavation and testing, and the development of conceptual and numerical models of the hydrologic processes at Yucca Mountain. Infiltration estimates by empirical and geochemical methods range from 0.2 to 1.4 mm/yr and 0.2–6.0 mm/yr, respectively. Infiltration estimates from numerical models range from 4.5 mm/yr to 17.6 mm/yr. Rock matrix properties vary vertically and laterally as the result of depositional processes and subsequent postdepositional alteration. Laboratory tests indicate that the average matrix porosity and hydraulic conductivity values for the main level of the proposed repository (Topopah Spring Tuff middle nonlithophysal zone) are 0.08 and 4.7 × 10−12 m/s, respectively. In situ fracture hydraulic conductivity values are 3–6 orders of magnitude greater. The permeability of fault zones is approximately an order of magnitude greater than that of the surrounding rock unit. Water samples from the fault zones have tritium concentrations that indicate some component of postnuclear testing. Gas and water vapor movement through the unsaturated zone is driven by changes in barometric pressure, temperature-induced density differences, and wind effects. The subsurface pressure response to surface barometric changes is controlled by the distribution and interconnectedness of fractures, the presence of faults and their ability to conduct gas and vapor, and the moisture content and matrix permeability of the rock units. In situ water potential values are generally less than −0.2 MPa (−2 bar), and the water potential gradients in the Topopah Spring Tuff units are very small. Perched-water zones at Yucca Mountain are associated with the basal vitrophyre of the Topopah Spring Tuff or the Calico

  14. Assessment of nonpoint-source contamination of the High Plains Aquifer in south-central Kansas, 1987

    Science.gov (United States)

    Helgesen, John O.; Stullken, Lloyd E.; Rutledge, A.T.

    1994-01-01

    Ground-water quality was assessed in a 5,000-square-mile area of the High Plains aquifer in south-central Kansas that is susceptible to nonpoint-source contamination from agricultural and petroleum-production activities. Of particular interest was the presence of agricultural chemicals and petroleum-derived hydrocarbons that might have been associated with brines that formerly were disposed into unlined ponds. Random sampling of ground water was done within a framework of discrete land-use areas (irrigated cropland, petroleum-production land containing former brine-disposal ponds, and undeveloped rangeland) of 3-10 square miles. Although true baseline water-quality conditions probably are rare, in this region they are represented most closely by ground water in areas of undeveloped rangeland. The sampling design enabled statistical hypothesis testing, using nonparametric procedures, of the effects of land use, unsaturated-zone lithology, and type of well sampled. Results indicate that regional ground-water quality has been affected by prevailing land-use activities, as shown by increased concentrations of several inorganic constituents. Ground water beneath irrigated cropland was characterized by significantly larger concentrations of hardness, alkalinity, calcium, magnesium, potassium, fluofide, and nitrite plus nitrate than was water beneath undeveloped rangeland. Few nondegraded pesticides were detected in the aquifer, probably because of degradation and sorption. Atrazine was the most common, but only in small concentrations. round water beneath petroleum-production land was characterized by significantly larger concentrations of hardness, alkalinity, dissolved solids, sodium, and chloride than was water beneath undeveloped rangeland. Nonpoint-source contamination by oil-derived hydrocarbons was not discernible. The occurrences of trace organic compounds were similar between petroleum-production land and undeveloped rangeland, which indicates a natural origin

  15. Geochemistry of the Arbuckle-Simpson Aquifer

    Science.gov (United States)

    Christenson, Scott; Hunt, Andrew G.; Parkhurst, David L.; Osborn, Noel I.

    2009-01-01

    The Arbuckle-Simpson aquifer in south-central Oklahoma provides water for public supply, farms, mining, wildlife conservation, recreation, and the scenic beauty of springs, streams, and waterfalls. A new understanding of the aquifer flow system was developed as part of the Arbuckle-Simpson Hydrology Study, done in 2003 through 2008 as a collaborative research project between the State of Oklahoma and the Federal government. The U.S. Geological Survey collected 36 water samples from 32 wells and springs in the Arbuckle-Simpson aquifer in 2004 through 2006 for geochemical analyses of major ions, trace elements, isotopes of oxygen and hydrogen, dissolved gases, and dating tracers. The geochemical analyses were used to characterize the water quality in the aquifer, to describe the origin and movement of ground water from recharge areas to discharge at wells and springs, and to determine the age of water in the aquifer.

  16. Assessing controls on perched saturated zones beneath the Idaho Nuclear Technology and Engineering Center, Idaho

    Science.gov (United States)

    Mirus, Benjamin B.; Perkins, Kim S.; Nimmo, John R.

    2011-01-01

    Waste byproducts associated with operations at the Idaho Nuclear Technology and Engineering Center (INTEC) have the potential to contaminate the eastern Snake River Plain (ESRP) aquifer. Recharge to the ESRP aquifer is controlled largely by the alternating stratigraphy of fractured volcanic rocks and sedimentary interbeds within the overlying vadose zone and by the availability of water at the surface. Beneath the INTEC facilities, localized zones of saturation perched on the sedimentary interbeds are of particular concern because they may facilitate accelerated transport of contaminants. The sources and timing of natural and anthropogenic recharge to the perched zones are poorly understood. Simple approaches for quantitative characterization of this complex, variably saturated flow system are needed to assess potential scenarios for contaminant transport under alternative remediation strategies. During 2009-2011, the U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy, employed data analysis and numerical simulations with a recently developed model of preferential flow to evaluate the sources and quantity of recharge to the perched zones. Piezometer, tensiometer, temperature, precipitation, and stream-discharge data were analyzed, with particular focus on the possibility of contributions to the perched zones from snowmelt and flow in the neighboring Big Lost River (BLR). Analysis of the timing and magnitude of subsurface dynamics indicate that streamflow provides local recharge to the shallow, intermediate, and deep perched saturated zones within 150 m of the BLR; at greater distances from the BLR the influence of streamflow on recharge is unclear. Perched water-level dynamics in most wells analyzed are consistent with findings from previous geochemical analyses, which suggest that a combination of annual snowmelt and anthropogenic sources (for example, leaky pipes and drainage ditches) contribute to recharge of shallow and

  17. Economics of Managed Aquifer Recharge

    Directory of Open Access Journals (Sweden)

    Robert G. Maliva

    2014-05-01

    Full Text Available Managed aquifer recharge (MAR technologies can provide a variety of water resources management benefits by increasing the volume of stored water and improving water quality through natural aquifer treatment processes. Implementation of MAR is often hampered by the absence of a clear economic case for the investment to construct and operate the systems. Economic feasibility can be evaluated using cost benefit analysis (CBA, with the challenge of monetizing benefits. The value of water stored or treated by MAR systems can be evaluated by direct and indirect measures of willingness to pay including market price, alternative cost, value marginal product, damage cost avoided, and contingent value methods. CBAs need to incorporate potential risks and uncertainties, such as failure to meet performance objectives. MAR projects involving high value uses, such as potable supply, tend to be economically feasible provided that local hydrogeologic conditions are favorable. They need to have low construction and operational costs for lesser value uses, such as some irrigation. Such systems should therefore be financed by project beneficiaries, but dichotomies may exist between beneficiaries and payers. Hence, MAR projects in developing countries may be economically viable, but external support is often required because of limited local financial resources.

  18. Lithospheric thinning beneath rifted regions of Southern California.

    Science.gov (United States)

    Lekic, Vedran; French, Scott W; Fischer, Karen M

    2011-11-11

    The stretching and break-up of tectonic plates by rifting control the evolution of continents and oceans, but the processes by which lithosphere deforms and accommodates strain during rifting remain enigmatic. Using scattering of teleseismic shear waves beneath rifted zones and adjacent areas in Southern California, we resolve the lithosphere-asthenosphere boundary and lithospheric thickness variations to directly constrain this deformation. Substantial and laterally abrupt lithospheric thinning beneath rifted regions suggests efficient strain localization. In the Salton Trough, either the mantle lithosphere has experienced more thinning than the crust, or large volumes of new lithosphere have been created. Lack of a systematic offset between surface and deep lithospheric deformation rules out simple shear along throughgoing unidirectional shallow-dipping shear zones, but is consistent with symmetric extension of the lithosphere.

  19. Simulation of Wave-Plus-Current Scour beneath Submarine Pipelines

    DEFF Research Database (Denmark)

    Eltard-Larsen, Bjarke; Fuhrman, David R.; Sumer, B. Mutlu

    2016-01-01

    A fully coupled hydrodynamic and morphologic numerical model was utilized for the simulation of wave-plus-current scour beneath submarine pipelines. The model was based on incompressible Reynolds-averaged Navier–Stokes equations, coupled with k-ω turbulence closure, with additional bed and suspen......A fully coupled hydrodynamic and morphologic numerical model was utilized for the simulation of wave-plus-current scour beneath submarine pipelines. The model was based on incompressible Reynolds-averaged Navier–Stokes equations, coupled with k-ω turbulence closure, with additional bed....... This validation complements previously demonstrated accuracy for the same model in simulating pipeline scour processes in pure-wave environments. The model was subsequently utilized to simulate combined wave-plus-current scour over a wide range of combined Keulegan–Carpenter numbers and relative current strengths...

  20. 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.

  1. 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.

  2. Kelvin-Helmholtz wave generation beneath hovercraft skirts

    Science.gov (United States)

    Sullivan, P. A.; Walsh, C.; Hinchey, M. J.

    1993-05-01

    When a hovercraft is hovering over water, the air flow beneath its skirts can interact with the water surface and generate waves. These, in turn, can cause the hovercraft to undergo violent self-excited heave motions. This note shows that the wave generation is due to the classical Kelvin-Helmholtz mechanism where, beyond a certain air flow rate, small waves at the air water interface extract energy from the air stream and grow.

  3. New interpretation of the deep mantle structure beneath eastern China

    Science.gov (United States)

    Ma, Pengfei; Liu, Shaofeng; Lin, Chengfa; Yao, Xiang

    2016-04-01

    Recent study of high resolution seismic tomography presents a large mass of high velocity abnormality beneath eastern China near the phase change depth, expanding more than 1600km-wide in East-west cross-section across the North China plate. This structure high is generally believed to be the subducted slab of Pacific plate beneath the Eurasia continent, while its origin and dynamic effect on the Cenozoic tectonic evolution of eastern China remain to be controversial. We developed a subduction-driven geodynamic mantle convection model that honors a set of global plate reconstruction data since 230Ma to help understand the formation and evolution of mantle structure beneath eastern China. The assimilation of plate kinematics, continuous evolving plate margin, asymmetric subduction zone, and paleo seafloor age data enables the spatial and temporal consistency between the geologic data and the mantle convection model, and guarantees the conservation of the buoyancy flux across the lithosphere and subducted slabs. Our model achieved a first order approximation between predictions and the observed data. Interestingly, the model suggests that the slab material stagnated above discontinuity didn't form until 15Ma, much later than previous expected, and the fast abnormality in the mid-mantle further west in the tomographic image is interpreted to be the remnants of the Mesozoic Izanagi subduction. Moreover, detailed analysis suggests that the accelerated subduction of Philippine Sea plate beneath Eurasia plate along the Ryukyu Trench and Nankai Trough since 15Ma may largely contribute to extending feature above 670km discontinuity. The long distance expansion of the slab material in the East-west direction may be an illusion caused by the approximate spatial perpendicularity between the cross-section and the subduction direction of the Philippine Sea plate. Our model emphasizes the necessity of the re-examination on the geophysical observation and its tectonic and

  4. On Irrotational Flows Beneath Periodic Traveling Equatorial Waves

    Science.gov (United States)

    Quirchmayr, Ronald

    2016-08-01

    We discuss some aspects of the velocity field and particle trajectories beneath periodic traveling equatorial surface waves over a flat bed in a flow with uniform underlying currents. The system under study consists of the governing equations for equatorial ocean waves within a non-inertial frame of reference, where Euler's equation of motion has to be suitably adjusted, in order to account for the influence of the earth's rotation.

  5. The Dumbarton Oaks Tlazolteotl: looking beneath the surface

    OpenAIRE

    MacLaren Walsh, Jane

    2014-01-01

    The Dumbarton Oaks Tlazolteotl: looking beneath the surface. Some of the earliest and most revered pre-Columbian artifacts in the world’s major museum and private collections were collected prior to the advent of systematic, scientific archaeological excavation, and have little or no reliable provenience data. They have consistently posed problems for researchers due to anomalies of theme, material, size, technical virtuosity and iconography. This paper offers a historical and scientific appr...

  6. Convective upwelling in the mantle beneath the Gulf of California.

    Science.gov (United States)

    Wang, Yun; Forsyth, Donald W; Savage, Brian

    2009-11-26

    In the past six million years, Baja California has rifted obliquely apart from North America, opening up the Gulf of California. Between transform faults, seafloor spreading and rifting is well established in several basins. Other than hotspot-dominated Iceland, the Gulf of California is the only part of the world's seafloor-spreading system that has been surrounded by enough seismometers to provide horizontal resolution of upper-mantle structure at a scale of 100 kilometres over a distance great enough to include several spreading segments. Such resolution is needed to address the long-standing debate about the relative importance of dynamic and passive upwelling in the shallow mantle beneath spreading centres. Here we use Rayleigh-wave tomography to image the shear velocity in the upper 200 kilometres or so of the mantle. Low shear velocities similar to those beneath the East Pacific Rise oceanic spreading centre underlie the entire length of the Gulf, but there are three concentrated locations of anomalously low velocities spaced about 250 kilometres apart. These anomalies are 40 to 90 kilometres beneath the surface, at which depths petrological studies indicate that extensive melting of passively upwelling mantle should begin. We interpret these seismic velocity anomalies as indicating that partial melting triggers dynamic upwelling driven by either the buoyancy of retained melt or by the reduced density of depleted mantle. PMID:19940924

  7. Flow separation and resuspension beneath shoaling nonlinear internal waves

    Science.gov (United States)

    Boegman, Leon; Ivey, Gregory N.

    2009-02-01

    Laboratory observations are presented showing the structure and dynamics of the turbulent bottom boundary layer beneath nonlinear internal waves (NLIWs) of depression shoaling upon sloping topography. The adverse pressure gradient beneath the shoaling waves causes the rear face to steepen, flow separation to occur, and wave-induced near-bottom vortices to suspend bed material. The resuspension is directly attributed to the near-bed viscous stress and to near-bed patches of elevated positive Reynolds stress generated by the vortical structures. These results are consistent with published field observations of resuspension events beneath shoaling NLIWs. Elevated near-bed viscous stresses are found throughout the domain at locations that are not correlated to the resuspension events. Near-bed viscous stress is thus required for incipient sediment motion but is not necessarily a precursor for resuspension. Resuspension is dependent on the vertical velocity field associated with positive Reynolds stress and is also found to occur where the mean (wave-averaged) vertical velocity is directed away from the bed. The results are interpreted by analogy to the eddy-stress and turbulent bursting resuspension models developed for turbulent channel flows.

  8. Recovery of datable charcoal beneath young lavas: lessons from Hawaii.

    Science.gov (United States)

    Lockwood, J.P.; Lipman, P.W.

    1980-01-01

    Field studies in Hawaii aimed at providing a radiocarbon-based chronology of prehistoric eruptive activity have led to a good understanding of the processes that govern the formation and preservation of charcoal beneath basaltic lava flows. Charcoal formation is a rate-dependent process controlled primarily by temperature and duration of heating, as well as by moisture content, density, and size of original woody material. Charcoal will form wherever wood buried by lava is raised to sufficiently high temperatures, but owing to the availability of oxygen it is commonly burned to ash soon after formation. Wherever oxygen circulation is sufficiently restricted, charcoal will be preserved, but where atmospheric oxygen circulates freely, charcoal will only be preserved at a lower temperature, below that required for charcoal ignition or catalytic oxidation. These factors cause carbonized wood, especially that derived from living roots, to be commonly preserved beneath all parts of pahoehoe flows (where oxygen circulation is restricted), but only under margins of aa. Practical guidelines are given for the recovery of datable charcoal beneath pahoehoe and aa. Although based on Hawaiian basaltic flows, the guidelines should be applicable to other areas. -Authors

  9. Transuranic distribution beneath a retired underground disposal facility, Hanford Site

    International Nuclear Information System (INIS)

    Past liquid waste disposal practices at the Hanford Site included the discharge of solutions containing low-level concentrations of transuranics directly to the ground via structures collectively termed cribs. A study was conducted to determine the present spatial distribution of plutonium and americium beneath the retired 216-Z-1A Crib, which contains one of the highest cumulative plutonium inventories, 57 kilograms. Sixteen shallow wells were drilled in the unsaturated sediments underlying the facility using specialized, totally contained drilling techniques. Samples from each well were analyzed to obtain profiles of both sediment type and plutonium and americium concentrations as a function of depth beneath the facility. The results of the study show that the highest concentration of plutonium (>104 nCi/g of sediment) occurs within the first 3 meters of sediment beneath the central distribution pipe. The high activity at this position is tentatively attributed to the removal of solid particles from the waste stream by sediment filtration. The distributions of plutonium and americium in the sediments are similar. Peak transuranic activity in the sediment profile is generally associated with silt lenses or with major sedimentary unit interfaces (ie, sand to gravel). The maximum vertical extent of transuranic activity found is approximately 30 meters below the bottom of the crib or approximately 25 meters above the regional water table. No contamination greater than the instrumental limit of detection of 10-5 nCi/g of sediment was found from a depth of 30 to 40 meters, the maximum depth of sampling

  10. Understanding the nature of mantle upwelling beneath East-Africa

    Science.gov (United States)

    Civiero, Chiara; Hammond, James; Goes, Saskia; Ahmed, Abdulhakim; Ayele, Atalay; Doubre, Cecile; Goitom, Berhe; Keir, Derek; Kendall, Mike; Leroy, Sylvie; Ogubazghi, Ghebrebrhan; Rumpker, Georg; Stuart, Graham

    2014-05-01

    The concept of hot upwelling material - otherwise known as mantle plumes - has long been accepted as a possible mechanism to explain hotspots occurring at Earth's surface and it is recognized as a way of removing heat from the deep Earth. Nevertheless, this theory remains controversial since no one has definitively imaged a plume and over the last decades several other potential mechanisms that do not require a deep mantle source have been invoked to explain this phenomenon, for example small-scale convection at rifted margins, meteorite impacts or lithospheric delamination. One of the best locations to study the potential connection between hotspot volcanism at the surface and deep mantle plumes on land is the East African Rift (EAR). We image seismic velocity structure of the mantle below EAR with higher resolution than has been available to date by including seismic data recorded by stations from many regional networks ranging from Saudi Arabia to Tanzania. We use relative travel-time tomography to produce P- velocity models from the surface down into the lower mantle incorporating 9250 ray-paths in our model from 495 events and 402 stations. We add smaller earthquakes (4.5 poorly sampled regions in order to have a more uniform data coverage. The tomographic results allow us to image structures of ~ 100-km length scales to ~ 1000 km depth beneath the northern East-Africa rift (Ethiopia, Eritrea, Djibouti, Yemen) with good resolution also in the transition zone and uppermost lower mantle. Our observations provide evidence that the shallow mantle slow seismic velocities continue trough the transition zone and into the lower mantle. In particular, the relatively slow velocity anomaly beneath the Afar Depression extends up to depths of at least 1000 km depth while another low-velocity anomaly beneath the Main Ethiopian Rift seems to be present in the upper mantle only. These features in the lower mantle are isolated with a diameter of about 400 km indicating deep

  11. Hydrogeochemistry and Origin of Thermal Groundwater in Bedrock Aquifers in Tianjin, China

    Institute of Scientific and Technical Information of China (English)

    Zhou Xun; Fang Bin; Shen Ye; Zhang Hua; Lin Li; Lin Jianwang

    2004-01-01

    Thermal groundwater resources were found to have occurred in deep-seated bedrock aquifers in the northeastern North China plain near Tianjin, China. Meso- to Neo-Proterozoic and Paleozoic carbonate rocks on the Cangxian uplift are capable of yielding 960-4 200 m3/d of 60 to 96 ℃ water from the wells ranging in depth between 1 000 and 4 000 m. Conductive heat flow of 0.063 to 0.144 2 W/m2 from the deep crust is responsible for this anomalous geothermal field. The water in the Ordovician aquifer is characterized by relatively high TDS, high concentrations of SO4 and SO4*Cl-Na*Ca type, but the waters from the Meso- to Neo-Proterozoic and Cambrian aquifers, by relatively low TDS, low concentrations of SO4 and predominantly Cl*SO4-Na type. It is noted that when the temperature of the waters increases at a rate of 10 ℃ in the range of 30-100 ℃, the content of SiO2 increases at a rate of 12 to 15 mg/L, and fluoride concentration increases at a rate of 2.3 to 2.5 mg/L. Hydrochemical and isotopic data suggest that the thermal water in the bedrock aquifers is of meteoric origin and recharged in the northern mountain area to the north of the Baodi-Ninghe fault, and then flows laterally for a long distance from the north to the south to the city of Tianjin. Temperature of the waters increases because of heat exchange with the rocks and recharge by conductive heat flow from beneath.

  12. YUCCA6 over-expression demonstrates auxin function in delaying leaf senescence in Arabidopsis thaliana

    KAUST Repository

    Kim, Jeong Im

    2011-04-21

    The Arabidopsis thaliana YUCCA family of flavin monooxygenase proteins catalyses a rate-limiting step in de novo auxin biosynthesis. A YUCCA6 activation mutant, yuc6-1D, has been shown to contain an elevated free IAA level and to display typical high-auxin phenotypes. It is reported here that Arabidopsis plants over-expressing YUCCA6, such as the yuc6-1D activation mutant and 35S:YUC6 transgenic plants, displayed dramatic longevity. In addition, plants over-expressing YUCCA6 exhibited classical, delayed dark-induced and hormone-induced senescence in assays using detached rosette leaves. However, plants over-expressing an allele of YUCCA6, that carries mutations in the NADPH cofactor binding site, exhibited neither delayed leaf senescence phenotypes nor phenotypes typical of auxin overproduction. When the level of free IAA was reduced in yuc6-1D by conjugation to lysine, yuc6-1D leaves senesced at a rate similar to the wild-type leaves. Dark-induced senescence in detached leaves was accompanied by a decrease in their free IAA content, by the reduced expression of auxin biosynthesis enzymes such as YUCCA1 and YUCCA6 that increase cellular free IAA levels, and by the increased expression of auxin-conjugating enzymes encoded by the GH3 genes that reduce the cellular free auxin levels. Reduced transcript abundances of SAG12, NAC1, and NAC6 during senescence in yuc6-1D compared with the wild type suggested that auxin delays senescence by directly or indirectly regulating the expression of senescence-associated genes. 2011 The Author(s).

  13. Recharge from rectangular areas to finite aquifers

    Science.gov (United States)

    Rao, N. H.; Sarma, P. B. S.

    1981-10-01

    A generalized analytical solution is derived for the growth of groundwater mound in finite aquifers bounded by open water bodies, in response to recharge from rectangular areas. Finite Fourier transforms are used to solve the linearized differential equation of groundwater flow. Unlike earlier solutions, the method presented here does not require the use of tables for evaluation of complicated functions. The solution is evaluated by comparison with existing numerical and analytical results. In stream-aquifer systems similar to those described above, application of the proposed solution is more realistic than using solutions available for infinite aquifers.

  14. YUCCA SCHIDIGERA AND ITS EFFECT ON RABBIT REPRODUCTION

    Directory of Open Access Journals (Sweden)

    Martina Földešiová

    2013-12-01

    Full Text Available The aim of this study was to evaluate the effect of Yucca schidigera plant on rabbit reproduction parameters. Six weeks old New Zealand White rabbit females (n=36 and males (n=20 were used in the experiment. Animals in the control groups (C does; n=12 and C bucks; n=7 were fed with commercially available diet and the diet in the experimental groups was enriched with 5g/100kg (E1 does; n=12 and E1 bucks; n=7 or 20 g/100kg (E2 does; n=12 and E2 bucks; n=6 of Yucca schidigera powder extract. The rabbits were fed for 280 days and weighed weekly. The highest semen concentration was in the second experimental group E2 (3.80±0.57 x 109/ml compared to control group C (2.84±0.33 x 109/ml and experimental group E1 (1.9±0.35 x 109/ml. Semen motility (E2- 85.55±6.19 %; E1- 85.28±2.27% and progressive motility (E2; 73.45±9.63 %; E1; 71.16±3.43% were higher in the experimental groups compared to the control groups (motility -78.69±5.17 %; progressive motility - 61.34±6.69 %. The highest conception and kindling rate was found out in the control group C (83 % and 83 %, respectively, slightly lower values were reported in the both experimental groups E1 and E2 (for conception rate - 63% and 63%, respectively; and for kindling rate - 63% and 63%, respectively. Evaluation of the number of liveborn young rabbits showed, in the experimental group 2 the number of liveborn young rabbits (9.43±1.65 was higher than in the control (C; 8.0±0.97 and the experimental group 1 (6.0±1.

  15. 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

  16. 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

  17. 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

  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

    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

  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 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

  2. 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.

  3. 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

  4. 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.

  5. Volcanic and sedimentary-rock aquifers

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the Volcanic and sedimentary-rock aquifers in the states of Montana, Wyoming, Idaho, Nevada, California, Oregon, and...

  6. Hydrogeology - MO 2014 Thermoclines Ozark Aquifer (SHP)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Ozark Aquifer thermo cline correlates the temperature data throughout the state in the Ordovician System and the Upper Cambrian Series, consisting of the Eminence...

  7. Aquifer vulnerability for Colorado and New Mexico

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The U.S. Geological Survey Data Series provides raster data representing an estimate of aquifer vulnerability calculated for each 30-meter raster cell. Depth to...

  8. Hydrogeologic characterization of devonian aquifers in Uruguay

    International Nuclear Information System (INIS)

    This article carried out the assistance research project implementation in devonian sedimentary units as a potentials aquifers and their best use to school supplying and rural population in central area of Uruguay.

  9. Nitrate reduction in an unconfined sandy aquifer

    DEFF Research Database (Denmark)

    Postma, Diederik Jan; Boesen, Carsten; Kristiansen, Henning;

    1991-01-01

    in the reduced zone of the aquifer are organic matter, present as reworked brown coal fragments from the underlying Miocene, and small amounts of pyrite at an average concentration of 3.6 mmol/kg. Electron balances across the redoxcline, based on concentrations of O2, NO3-, SO4(2-) and total inorganic carbon......Nitrate distribution and reduction processes were investigated in an unconfined sandy aquifer of Quaternary age. Groundwater chemistry was studied in a series of eight multilevel samplers along a flow line, deriving water from both arable and forested land. Results show that plumes of nitrate......-contaminated groundwater emanate from the agricultural areas and spread through the aquifer. The aquifer can be subdivided into an upper 10- to 15-m thick oxic zone that contains O2 and NO3-, and a lower anoxic zone characterized by Fe2+-rich waters. The redox boundary is very sharp, which suggests that reduction...

  10. As contamination in Mercedes (Uruguay) aquifer groundwater

    International Nuclear Information System (INIS)

    The study presents data on the concentration of arsenic in groundwater aquifer Mercedes, where the highest concentration area is located in New Palmira.A geological formation decryption of the Mercedes for the Upper Cretaceous is made.

  11. North Atlantic Coastal Plain aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the North Atlantic Coastal Plain aquifer system in North Carolina, Virginia, Maryland, Deleware, and New Jersey.

  12. Evidence for dike emplacement beneath Iliamna Volcano, Alaska in 1996

    Science.gov (United States)

    Roman, D.C.; Power, J.A.; Moran, S.C.; Cashman, K.V.; Doukas, M.P.; Neal, C.A.; Gerlach, T.M.

    2004-01-01

    Two earthquake swarms, comprising 88 and 2833 locatable events, occurred beneath Iliamna Volcano, Alaska, in May and August of 1996. Swarm earthquakes ranged in magnitude from -0.9 to 3.3. Increases in SO2 and CO2 emissions detected during the fall of 1996 were coincident with the second swarm. No other physical changes were observed in or around the volcano during this time period. No eruption occurred, and seismicity and measured gas emissions have remained at background levels since mid-1997. Earthquake hypocenters recorded during the swarms form a cluster in a previously aseismic volume of crust located to the south of Iliamna's summit at a depth of -1 to 4 km below sea level. This cluster is elongated to the NNW-SSE, parallel to the trend of the summit and southern vents at Iliamna and to the regional axis of maximum compressive stress determined through inversion of fault-plane solutions for regional earthquakes. Fault-plane solutions calculated for 24 swarm earthquakes located at the top of the new cluster suggest a heterogeneous stress field acting during the second swarm, characterized by normal faulting and strike-slip faulting with p-axes parallel to the axis of regional maximum compressive stress. The increase in earthquake rates, the appearance of a new seismic volume, and the elevated gas emissions at Iliamna Volcano indicate that new magma intruded beneath the volcano in 1996. The elongation of the 1996-1997 earthquake cluster parallel to the direction of regional maximum compressive stress and the accelerated occurrence of both normal and strike-slip faulting in a small volume of crust at the top of the new seismic volume may be explained by the emplacement and inflation of a subvertical planar dike beneath the summit of Iliamna and its southern satellite vents. ?? 2003 Elsevier B.V. All rights reserved.

  13. A magmatic probe of dynamic topography beneath western North America

    Science.gov (United States)

    Klöcking, M.; White, N. J.; Maclennan, J.

    2014-12-01

    A region centered on the Yellowstone hotspot and encompassing the Colorado Plateau sits at an elevation 2 km higher than the cratonic North America. This difference broadly coincides with tomographically observed variations in lithospheric thickness: ~120 km beneath western North America, ~240 km beneath the craton. Thermochronology of the Grand Canyon area, sedimentary flux to the Gulf of Mexico, and river profile inversion all suggest that regional uplift occurred in at least two separate stages. High resolution seismic tomographic models, using USArray data, have identified a ring of low velocity material beneath the edges of the Colorado Plateau. Magmatism coincides with these low velocity zones and shows distinct phases: an overall increase in volume around 40 Ma and a change from lithospheric to asthenospheric signatures around 5 Ma. Volcanism is also observed to migrate north-east with time. Here, we attempt to integrate these different observations with lithospheric thickness. A dynamic topography model of progressive lithospheric erosion over a hot mantle plume might account for uplift as well as the temporal and spatial distribution of magmatism across western North America. Thinning of the lithosphere around the edges of the Colorado Plateau in combination with the hotter mantle potential temperature of a plume could create isostatic and dynamic uplift as well as allowing for melt production. To test this model, we have analysed around 100 samples from volcanic centers across western North America by ICP-MS for rare earth elements (REE). Most of the samples are younger than 5 Ma, and all of them have previously been analysed by XRF. Using trace element ratios such as La/Yb and Nb/Y we assess depth of melting and melt fraction, respectively. In addition, we use REE inversion modelling to estimate melt fractions as a function of depth and temperature of melting. The results are compared to existing constraints on lithospheric thickness and mantle potential

  14. Three-dimensional attenuation structure beneath North Island, New Zealand

    Science.gov (United States)

    Satake, Kenji; Hashida, Toshihiko

    1989-03-01

    Three-dimensional attenuation structure beneath North Island, New Zealand is determined by inversion of seismic intensity data. The method developed by Hashida and Shimazaki is used; the seismic intensity is converted to the maximum acceleration of the S-wave to obtain the acceleration at a point source and the attenuation structure. Because seismic intensity data have been accumulated on a uniform scale in New Zealand since the 1950's, we were able to use more than 2000 seismic intensity data from 26 earthquakes. The results show a remarkable contrast in the attenuation structure. In the top crustal layer, a low-Q area corresponding to the Central Volcanic Region is found. This low-Q area becomes wider to the northeast of North Island, suggesting that the Central Volcanic Region continues to the Havre Trough, a young back-arc basin. The southeastern part of the upper mantle beneath North Island shows high Q while the northwestern part shows low Q. The cross section shows that the high-Q region is dipping to the northwest, with a large amount of dip in the northeast and a smaller dip in the southwestern part of North Island. A comparison of the attenuation structure with microearthquake distribution indicates that this high-Q zone is the obliquely subducting Pacific plate. A zone of abnormally low Q which has cut the high-Q slab is found at a depth range of 130 to 230 km beneath the active volcanoes in the Taupo Volcanic Zone. A tear in the Pacific plate is suggested by this discontinuity in the attenuation structure. (1984).

  15. The flow beneath a periodic travelling surface water wave

    International Nuclear Information System (INIS)

    We discuss some recent results on the behaviour of the velocity field, pressure and particle trajectories beneath a periodic travelling wave propagating at the surface of water with a flat bed, in a flow without underlying currents. By analysing the governing equations we avoid approximations, thus ensuring the validity of the results without restrictions on the wave amplitude. In particular, the presented approach applies to waves of large amplitude. We also formulate some open problems, venturing into the relatively unexplored field of wave–current interactions. (topical review)

  16. The ionospheric heating beneath the magnetospheric cleft revisited

    Directory of Open Access Journals (Sweden)

    G. W. Prölss

    2005-03-01

    Full Text Available A prominent peak in the electron temperature of the topside ionosphere is observed beneath the magnetospheric cleft. The present study uses DE-2 data obtained in the Northern Winter Hemisphere to investigate this phenomenon. First, the dependence of the location and magnitude of the temperature peak on the magnetic activity is determined. Next, using a superposed epoch analysis, the mean latitudinal profile of the temperature enhancement is derived. The results of the present study are compared primarily with those obtained by Titheridge (1976, but also with more recent observations and theoretical predictions.

  17. On the Turbulence Beneath Finite Amplitude Water Waves

    CERN Document Server

    Babanin, Alexander V

    2015-01-01

    The paper by Beya et al. (2012, hereinafter BPB) has a general title of Turbulence Beneath Finite Amplitude Water Waves, but is solely dedicated to discussing the experiment by Babanin and Haus (2009, hereinafter BH) who conducted measurements of wave-induced non-breaking turbulence by particle image velocimetry (PIV). The authors of BPB conclude that their observations contradict those of BH. Here we argue that the outcomes of BPB do not contradict BH. In addition, although the main conclusion of BPB is that there is no turbulence observed in their experiment, it actually is observed.

  18. Crustal structure beneath China from receiver function analysis

    Science.gov (United States)

    Chen, Youlin; Niu, Fenglin; Liu, Ruifeng; Huang, Zhibin; TkalčIć, Hrvoje; Sun, Li; Chan, Winston

    2010-03-01

    We collected and processed a large amount of high-quality broadband teleseismic waveform data recorded by the 48 Chinese National Digital Seismic Network stations to estimate large-scale lateral variations of crustal thickness and Vp/Vs ratio (hence Poisson's ratio) beneath China. A statistical method was used to select mutually coherent receiver functions at each station, which yielded over 200 traces for most of the stations. With the conventional H-κ (the crustal thickness and Vp/Vs ratio) approach, there is a large trade-off between H and κ. Consequently, multiple maxima are frequently observed in the H-κ domain. We introduced a weight function that measures the coherence between the P-to-S conversion and the reverberation phases at each H-κ grid to reduce the trade-off. A 4th-root stacking method was further applied to reduce uncorrelated noise relative to the linear stack. These modifications turned out to be very effective in reducing the H-κ trade-off and yielded reliable estimates of crustal thickness and Vp/Vs ratio. The crust beneath eastern China is as thin as 31-33 km and the underlying Moho is relatively flat and sharp. In the western part of China, the crust is considerably thicker and shows large variations. The Moho is observed at about 51 km depth along the Tian Shan fold system and about 84 km deep beneath the central part of the Tibetan Plateau. The transition occurs at the so-called N-S belt between about 100° and 110°E, which is featured by unusually high seismicity and large gravity anomalies. The average Vp/Vs ratio over the mainland China crust is about 1.730 (σ = 0.249), significantly lower than the global average 1.78 (σ = 0.27) of the continental crust. This lower Vp/Vs ratio may suggest a general absence of mafic lowermost crustal layer beneath China.

  19. Improving Aquifer Thermal Energy Storage Efficiency

    OpenAIRE

    S. Kranz; G. Blöcher; Ali Saadat

    2015-01-01

    Aquifer thermal energy storage systems play an important role for the future energy supply systems. Such systems can decouple energy availability (e.g. fluctuating renewable energy, waste heat) and energy supply in times of demand. In order to fully contribute to the sustainability of energy supply, the essential requirements of energy storages are high energy efficiency, high reliability, cost effectiveness, as well as operational flexibility. Aquifer Thermal Energy Storage Systems (ATES) me...

  20. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-03-31

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

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. 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.

  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. Tracing Recharge Sources and Salinization Processes of the Quaternary Aquifer Using Stable Isotopes and Hydrogeochemistry, South of the Ismailia Canal, Egypt

    Science.gov (United States)

    Khalil, M. M. A. M.; Tokunaga, T.

    2014-12-01

    The reclamation policy to alleviate overpopulation problem of the Nile Delta, Egypt, has created both quality and quantity problems for the Quaternary aquifer beneath the reclaimed areas. It is partly because of the less well managed way for land use planning and lack of the environmental impact assessment at least at the early stage of the development. A stable isotopic ( δ 18O and δ 2H) and hydrochemical investigation was carried out in the reclaimed area at the south of the Ismailia Canal to identify recharge sources, and mixing and salinization processes of the Quaternary aquifer. On the basis of the isotopic data, four end-members, i.e., the Quaternary aquifer, the Miocene aquifer, surface freshwater and wastewater ponds were found to be mixed in different degree in the study area. As a consequence of mixing with groundwater in the Miocene aquifer which shows highly saline and depleted isotopic signature, groundwater in the Quaternary aquifer was found to have a depleted isotopic trend towards south, i.e., toward structural highs. On the contrary, northward trends of the enriched isotopic values and lower EC values in the Quaternary aquifer indicated the mixing with surface water. Local abnormal EC values at an agricultural area and the vicinity of well field were considered to be related to the excessive pumping for irrigation and reclamation activities which in turn resulted in upconing of deeper saline groundwater. Mixing pattern also suggested local contribution of the wastewater ponds to the recharge process, which is consistent with the previously reported heavy metal contamination in the vicinity of these ponds, indicating the necessity to protect and remediate the subsurface water resources in the area.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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

  20. 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.

  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. 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

  3. 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

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. 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

  9. 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.

  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. Shear Wave Splitting Observations Beneath Uturuncu Volcano, Bolivia

    Science.gov (United States)

    Sims, N. E.; Christensen, D. H.; Moore-Driskell, M. M.

    2015-12-01

    Anisotropy in the upper mantle is often associated with mantle flow direction through the lattice preferred orientation of anisotropic minerals such as olivine in the upper mantle material. The flow of the mantle around subduction zones can be particularly complex, and thus difficult to explain. Because of its relationship to anisotropy, analysis of shear wave splitting measurements can help to answer questions regarding the upper mantle flow that surrounds subducting slabs. Here we present SK(K)S shear wave splitting measurements from a temporary broadband network (PLUTONS) of 33 stations deployed from April 2009 to October 2012 on the Altiplano plateau around Uturuncu volcano in Bolivia. The stations are spaced 10-20 km apart, providing a high spatial resolution of the region of the mantle directly below Uturuncu volcano. Despite the lack of numerous splitting results to analyze, preliminary measurements indicate a relatively consistent pattern of fast-polarization directions in a NW-SE orientation of about N80ºW. We think that it is likely that these observations come from anisotropy in the mantle wedge above the subducting Nazca plate indicating a direction of flow in the mantle wedge that is sub-parallel to the subduction direction of the Nazca plate. Although W-E flow beneath the subducting Nazca plate cannot be completely ruled out, these results appear to be consistent with the simple model of two-dimensional corner flow in the mantle wedge and slab-entrained mantle flow beneath the slab.

  12. Shear wave anisotropy in D" region beneath the western Pacific

    Institute of Scientific and Technical Information of China (English)

    DAI Zhi-yang; LIU Bin; WANG Xiao-xiang; ZHA Xian-jie; ZHANG Hu; YANG Feng-qin

    2007-01-01

    Using seismic shear phases from 47 Tonga-Fiji and its adjacent region events recorded by the CENC and IRIS, and from 26 northeast Asia and north Pacific events recorded by IRIS, we studied the shear wave anisotropy in D" region beneath the western Pacific utilizing the ScS-S differential travel time method and obtained the splitting time values between the radial and transverse components of each ScS wave corresponding to each core-mantle boundary (CMB) reflection point. We found that most shear waves involved horizontally polarized shear wave components traveling faster than vertically polarized shear wave components through the D" region. The splitting time values of ScS wave range from (0.91 s to 3.21 s with an average value of 1.1 s. The strength of anisotropy varies from (0.45% to 1.56% with an average value of 0.52%. The observations and analyses show that in the D" region beneath the western Pacific the lateral flow is expected to be dominant and the vertical transverse isotropy may be the main anisotropic structure. This structure feature may be explained by the shape preferred orientation of the CMB chemical reaction products or partial melt and the lattice preferred orientation of the lower mantle materials caused by the lateral flow at lowermost mantle.

  13. Investigating the Spatial and Temporal Variability of Water Saturation Within the Greenland Firn Aquifer Using Ground Penetrating Radar

    Science.gov (United States)

    Brautigam, N.

    2015-12-01

    Ground Penetrating Radar (GPR) is used to investigate the spatial and temporal saturation of the Greenland firn aquifer, using a method recently developed on a Svalbard icesheet (Christianson et. al., 2015). Currently, saturation of the firn is assumed to be 100% (Koenig et. al., 2014; Forster et. al., 2014), and using a firn density correction this saturation level drives the present liquid water volume estimate (140±20 Gt) of the Greenland firn aquifer (Koenig et. al., 2014). Based on earlier studies on mountain glacier firn aquifers, we suspect that saturation levels vary with depth, annual precipitation patterns, and local topography (Fountain, 1989; Christianson et. al., 2015). Refining the liquid water volume estimation is an important parameter as it allows for a better determination of the amount of water potentially available for release and consequent sea level rise, as well as to better model glacial processes such as englacial flow, crevasse fracture, and basal lubrication. GPR and GPS data collected along a 2.6 km transect in 2011, 2013, and 2014 in southeastern Greenland is used to measure the spatial and temporal variability of saturation levels within the aquifer. A bright reflector seen in the GPR at the water table depth responds to local topography. At surface lows, the reflector rises, intersecting annual density change layers visible in the GPR data. At these intersections, the annual layers deflect down beneath the water table before being lost due to signal attenuation. We assume that this deflection is due to a change in dielectric permittivity, and that by measuring the angle of deflection, and implementing a mixing model and density correction from nearby firn cores, we can determine the saturation level at each point along a deflection. This allows us to investigate the spatial and temporal variability of saturation within the firn aquifer.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-06-01

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

  20. 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

  1. 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

  2. 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.

  3. 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

  4. 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

  5. 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

  6. Basement Aquifers : How Useful Are Gravity Data ?

    Science.gov (United States)

    Genthon, P.; Mouhouyouddine, A. H.; Hinderer, J.; Hector, B.; Yameogo, S.

    2014-12-01

    Gravity data with a few microgal precision were proved to be able to constrain the specific yield of various kinds of aquifer in West Africa from annual fluctuations of both the gravimetric and piezometric signals (Pfeffer et al., Geophys. J. Int., 2011; Hector et al., Geophys. J. Int., 2013). However some recent papers reported a disappointing potential of gravity measurements during a pumping experiment in a sandy aquifer (Blainey et al., WRR, 2007; Herckenrath et al., WRR, 2012) and their poor ability in constraining the transmissity and specific yield of the aquifer, which are the parameters to which pumping tests give access. Fresh basement rocks present generally a null porosity and the structure of basement aquifers is given by the weathering profile. In tropical climate, this profile consists of a few tens meter thick saprolite layer, with noticeable porosity but low permeability overlying the weathering front. This weathering front includes in many instances a fractured medium and presents a high permeability with variable porosity. It is hardly sampled in coring experiments. We present some numerical simulation results on the ability of gravity to constrain the transmissivity of this medium. Due to poroelasticity of clay minerals in the saprolite, soil subsidence is expected to occur during pumping with a significant gravity effect. Gravity measurements have therefore to be completed with leveling data at a millimetric precision. We present first the results of numerical modeling of the gravity and subsidence for a theoretical horizontally stratified basement aquifer, and show that gravity and leveling are able to provide independently the poroelasticity coefficient and a single transmissivity coefficient for the bottom of the aquifer, if the properties of the upper saprolites are known. We will discuss then the general case, where the aquifer presents a vertical fracture where the weathering profile thickens.

  7. Multidepth pumping tests in deep aquifers.

    Science.gov (United States)

    Alam, N; Olsthoorn, T N

    2014-09-01

    Multidepth pumping tests (MDPTs), in which different sections of a screen are pumped in sequence, are not being used by hydrogeologists, despite the capability of such tests to resolve uncertainties in the estimation of aquifer characteristics. MDPTs can be used to discern the effects of partial penetration and vertical anisotropy. This article demonstrates the use of MDPTs for a deep and vertically anisotropic aquifer, based on a real and unique series of pumping tests conducted in the Indus Basin. Traditional single-layer methods, which incorporate partial penetration and vertical scaling, were employed to evaluate these tests. However, the drawdowns of the 19 piezometers at different depths for which times series data were available could not be matched, presumably because of the layered structure of the aquifer. Numerical (MODFLOW) and multilayer analytical (Hemker and Maas 1987; Hemker 1999) approaches were used to assess the benefits of using MDPTs in the analysis of deep layered and anisotropic aquifers. The multilayer analytical solution results are consistent with the measured and numerically computed drawdowns. The original step-drawdown data were used to verify the model independently. The results of statistical analyses indicate that the parameters for a three-layer system are uniquely estimated. A sensitivity analysis showed that aquifer depths greater than 900 m do not affect the drawdown. The multilayer analytical solution was implemented in MATLAB and can be found in the online version of this article. This multilayer analytical approach was implemented in MLU by Hemker and Randall (2013) for up to 40 layers. The results of this study will be useful in groundwater management, exploration, and optimal well depth estimation for the Indus Basin aquifer and other vertically heterogeneous aquifers. PMID:24428328

  8. Lead isotopes and trace metals in dust at Yucca Mountain

    Science.gov (United States)

    Kwak, Loretta; Neymark, Leonid A.; Peterman, Zell E.

    2008-01-01

    Lead (Pb)-isotope compositions and trace-metal concentrations were determined for samples of dust collected from underground and surface locations at and near the proposed radioactive waste repository at Yucca Mountain, Nevada. Rare earth element concentrations in the dust samples from the underground tunnels are similar to those in wholerock samples of the repository host rocks (Miocene Tiva Canyon Tuff and Topopah Spring Tuff), supporting interpretation that the subsurface dust is mainly composed of rock comminuted during tunnel construction. Other trace metals (arsenic, cadmium, cobalt, chromium, copper, manganese, nickel, lead, antimony, thallium, and zinc) are variably enriched in the subsurface dust samples relative to the average concentrations in the host rocks. Average concentrations of arsenic and lead in dust samples, high concentrations of which can cause corrosion of waste canisters, have enrichment factors from 1.2 to 1.6 and are insignificant relative to the range of concentrations for these metals observed in the host rock samples. Most dust samples from surface sites also are enriched in many of these trace metals relative to average repository host rocks. At least some of these enrichments may be artifacts of sampling. Plotted on a 208Pb/206Pb-207Pb/206Pb graph, Pb-isotope compositions of dust samples from underground sites form a mixing line extending from host-rock Pb-isotope compositions towards compositions of many of the dust samples from surface sites; however, combined Pb concentration and isotope data indicate the presence of a Pbenriched component in the subsurface dust that is not derived from host rock or surface dust and may derive from anthropogenic materials introduced into the underground environment.

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. Physical limits on ground motion at Yucca Mountain

    Science.gov (United States)

    Andrews, D.J.; Hanks, T.C.; Whitney, J.W.

    2007-01-01

    Physical limits on possible maximum ground motion at Yucca Mountain, Nevada, the designated site of a high-level radioactive waste repository, are set by the shear stress available in the seismogenic depth of the crust and by limits on stress change that can propagate through the medium. We find in dynamic deterministic 2D calculations that maximum possible horizontal peak ground velocity (PGV) at the underground repository site is 3.6 m/sec, which is smaller than the mean PGV predicted by the probabilistic seismic hazard analysis (PSHA) at annual exceedance probabilities less than 10-6 per year. The physical limit on vertical PGV, 5.7 m/sec, arises from supershear rupture and is larger than that from the PSHA down to 10-8 per year. In addition to these physical limits, we also calculate the maximum ground motion subject to the constraint of known fault slip at the surface, as inferred from paleoseismic studies. Using a published probabilistic fault displacement hazard curve, these calculations provide a probabilistic hazard curve for horizontal PGV that is lower than that from the PSHA. In all cases the maximum ground motion at the repository site is found by maximizing constructive interference of signals from the rupture front, for physically realizable rupture velocity, from all parts of the fault. Vertical PGV is maximized for ruptures propagating near the P-wave speed, and horizontal PGV is maximized for ruptures propagating near the Rayleigh-wave speed. Yielding in shear with a Mohr-Coulomb yield condition reduces ground motion only a modest amount in events with supershear rupture velocity, because ground motion consists primarily of P waves in that case. The possibility of compaction of the porous unsaturated tuffs at the higher ground-motion levels is another attenuating mechanism that needs to be investigated.

  14. 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

  15. 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

  16. Chemical characteristics of water in the surficial aquifer system, Broward County, Florida

    Science.gov (United States)

    Howie, Barbara

    1987-01-01

    Water quality data was collected in 1981 and 1982 during the drilling of test holes at 27 sites throughout Broward County, Florida. Determinations were made for the following physical properties and chemical constituents: pH, alkalinity, specific conductance, major ions, selected nutrients and dissolved iron, aluminum, and manganese. Determinations for the trace elements-arsenic, barium, cadmium, chromium, lead, zinc, selenium, and mercury-were made at 14 wells. Water in the surficial aquifer system between the coastal ridge and the conservation areas is potable and usually is a calcium bicarbonate type for the first 140 ft or more below land surface. Between depths of 140 and 230 ft, groundwater generally grades into a mixed-ion water type. In some areas, diluted seawater occurs beneath the mixed water zone. Dissolved iron concentrations between the coastal ridge and the conservation areas are variable but generally exceed 1,000 micrograms/L. Beneath the conservation areas and the western edge of Broward County, groundwater in the first 100 ft below land surface generally is either a calcium bicarbonate type or a mixed-ion type. At depths between 100 and 200 ft, diluted residual seawater occurs, except along the far western edge of the county. Residual seawater is least diluted in the north. Dissolved iron concentrations generally are between 300 and 1 ,000 micrograms/L but increase to the east of the conservation areas. Other findings of the investigation include: (1) groundwater in some areas west of the coastal ridge probably would be suitable for most domestic, agricultural, and industrial uses if it were treated for carbonate hardness; (2) groundwater in much of Broward County is chemically altered by natural softening and magnesium enrichment (natural softening increases to the west and is very pronounced beneath the far western edge of the county); and (3) there is evidence of mineralized water from the conservation areas mixing with groundwater east of the

  17. Slab melting and magma formation beneath the southern Cascade arc

    Science.gov (United States)

    Walowski, K. J.; Wallace, P. J.; Clynne, M. A.; Rasmussen, D. J.; Weis, D.

    2016-07-01

    The processes that drive magma formation beneath the Cascade arc and other warm-slab subduction zones have been debated because young oceanic crust is predicted to largely dehydrate beneath the forearc during subduction. In addition, geochemical variability along strike in the Cascades has led to contrasting interpretations about the role of volatiles in magma generation. Here, we focus on the Lassen segment of the Cascade arc, where previous work has demonstrated across-arc geochemical variations related to subduction enrichment, and H-isotope data suggest that H2O in basaltic magmas is derived from the final breakdown of chlorite in the mantle portion of the slab. We use naturally glassy, olivine-hosted melt inclusions (MI) from the tephra deposits of eight primitive (MgO > 7 wt%) basaltic cinder cones to quantify the pre-eruptive volatile contents of mantle-derived melts in this region. The melt inclusions have B concentrations and isotope ratios that are similar to mid-ocean ridge basalt (MORB), suggesting extensive dehydration of the downgoing plate prior to reaching sub-arc depths and little input of slab-derived B into the mantle wedge. However, correlations of volatile and trace element ratios (H2O/Ce, Cl/Nb, Sr/Nd) in the melt inclusions demonstrate that geochemical variability is the result of variable addition of a hydrous subduction component to the mantle wedge. Furthermore, correlations between subduction component tracers and radiogenic isotope ratios show that the subduction component has less radiogenic Sr and Pb than the Lassen sub-arc mantle, which can be explained by melting of subducted Gorda MORB beneath the arc. Agreement between pMELTS melting models and melt inclusion volatile, major, and trace element data suggests that hydrous slab melt addition to the mantle wedge can produce the range in primitive compositions erupted in the Lassen region. Our results provide further evidence that chlorite-derived fluids from the mantle portion of the

  18. Imaging Transition Zone Thickness Beneath South America from SS Precursors

    Science.gov (United States)

    Schmerr, N.; Garnero, E.

    2006-12-01

    We image detailed upper mantle discontinuity structure beneath a number of geologically active regions, including the South American subduction zone, the Scotia plate subduction zone, and several volcanic hotspots (e.g., the Galapagos Islands), in a region ~10,000 km by 10,000 km wide, spanning 70° S to 20° N and 20° W to 110° W. Precursors to the seismic phase SS are analyzed, which form as a result of underside reflections off seismic discontinuities beneath the midpoint of the SS path and are highly sensitive to discontinuity depth and sharpness. Our SS dataset consists of over 15,000 high-quality transverse component broadband displacement seismograms collected from the Incorporated Research Institutions for Seismology (IRIS), the Canadian National Seismic Network (CNSN), as well as data from EarthScope seismic stations, and from the Canadian Northwest Experiment (CANOE) temporary broadband array deployment. This dataset densely samples several regions in our study area and significantly improves the sampling for this area compared to previous precursor studies. Data with common central SS bouncepoints are stacked to enhance precursory phases. Solution discontinuity structure depends on a number of factors, including dominant seismic period, crustal correction, signal-to-noise ratio threshold, and tomography model used for mantle heterogeneity correction. We exclude precursor data predicted to interfere with other seismic phases, such as topside reflections (e.g., s670sS), which have been demonstrated to contaminate final stacks. Solution transition zone thickness is at least 20 km thicker than global average estimates of 242 km along the northwestern portion of the South American subduction complex (Peru, Ecuador, and Columbia); this thickening extends 1000-1500 km to the east beneath the continent, but does not appear to continue south of -20° latitude along the convergent margin. A minimum of 10 km of thickening is imaged to the west of the Scotia

  19. Pn anisotropic tomography and mantle dynamics beneath China

    Science.gov (United States)

    Zhou, Zhigang; Lei, Jianshe

    2016-08-01

    We present a new high-resolution Pn anisotropic tomographic model of the uppermost mantle beneath China inferred from 52,061 Pn arrival-time data manually picked from seismograms recorded at provincial seismic stations in China and temporary stations in Tibet and the Tienshan orogenic belt. Significant features well correlated with surface geology are revealed and provide new insights into the deep dynamics beneath China. Prominent high Pn velocities are visible under the stable cratonic blocks (e.g., the Tarim, Junngar, and Sichuan basins, and the Ordos block), whereas remarkable low Pn velocities are observed in the tectonically active areas (e.g., Pamir, the Tienshan orogenic belt, central Tibet and the Qilian fold belt). A distinct N-S trending low Pn velocity zone around 86°E is revealed under the rift running from the Himalayan block through the Lhasa block to the Qiangtang block, which indicates the hot material upwelling due to the breaking-off of the subducting Indian slab. Two N-S trending low Pn velocity belts with an approximate N-S Pn fast direction along the faults around the Chuan-Dian diamond block suggest that these faults may serve as channels of mantle flow from Tibet. The fast Pn direction changes from N-S in the north across 27°N to E-W in the south, which may reflect different types of mantle deformation. The anisotropy in the south could be caused by the asthenospheric flow resulted from the eastward subduction of the Indian plate down to the mantle transition zone beneath the Burma arc. Across the Talas-Fergana fault in the Tienshan orogenic belt, an obvious difference in velocity and anisotropy is revealed. To the west, high Pn velocities and an arc-shaped fast Pn direction are observed, implying the Indo-Asian collision, whereas to the east low Pn velocities and a range-parallel Pn fast direction are imaged, reflecting the northward underthrusting of the Tarim lithosphere and the southward underthrusting of the Kazakh lithosphere. In

  20. Hydrogeology of the stratified-drift aquifers in the Cayuta Creek and Catatonk Creek valleys in parts of Tompkins, Schuyler, Chemung, and Tioga Counties, New York

    Science.gov (United States)

    Miller, Todd S.; Pitman, Lacey M.

    2012-01-01

    Creek stratified-drift aquifers is predominantly from the valley walls toward the main streams in the valleys. The groundwater discharges from the aquifer system to the main-stem streams in the valleys. Locally, the direction of groundwater flow is radially away from groundwater mounds that have formed beneath upland tributaries that typically lose water where they flow on alluvial fans in the valleys. In some places, groundwater that would normally flow toward streams is intercepted by pumping wells.

  1. Ecological assessment of water quality in relation to hydrogeology in a shallow urban aquifer: Somesul Mic River aquifer (North-Western, Romania)

    Science.gov (United States)

    Iepure, Sanda; Marin, Constantin; Fekete, Alexandru; Rajka, Geza; Brad, Traian; Samsudean, Cristian

    2014-05-01

    The River Basin Management Plan is the main instrument for the implementation of the Water Framework Directive (2000/60/CE), one of its main requirements being the evaluation and quantification of human impacts on aquatic environments including the groundwater or groundwater dependent ecosystems. The Someş-Tisa basin is the largest hydrographical basin in NW Romania (22,380 km2), containing 15 Quaternary detrital groundwater bodies prone to intensive agricultural and urban industrial use. So far, no studies have addressed the groundwater fauna assemblages and their ecological response to human disturbances and aquifer contamination. Here we investigate a Quaternary shallow detrital aquifer (urban-industrial and agricultural contaminants, aiming to evaluate the sensitivity and structural patterns of groundwater crustaceans communities to aquifer contamination with trace metals (Cr, Mn, Co, Ni, Cu, Zn, Cd, Mo, Pb), As, Se and nitrates. We conducted a survey in seven monitoring boreholes (1-8 m beneath the surface) through the Quaternary porrous aquifer of the Somesul Mic River on a 10 km long longitudinal transect. Hydrologic and geologic variables (rainfall amount, drainage network density, aquifer and drainage elevation, transmisivity and aquifer porosity) were extracted from previous works and Pearson correlations were calculated for paired variables. Water and faunal sampling was performed on a seasonal basis at one pristine and six impacted sites during 2013. Invertebrates were sampled with a submersible pump by extracting a volume of 50-100 l of water and filtering through a 63 microns planktonic net. Subsequently, 2 l of water was extracted after pumping for compositional analyses of major constituents, trace elements (by ICP-MS) and nutrients. The results of water geochemical analyses indicate a significant pollutant charge of groundwater with Mn (max. 29.26 μg/l), Ni (16.55 μg/l), Fe (509.74 μg/l), As (3.87 μg/l), Se (5.07 μg/l), sulphates (549.9

  2. Flow and transport within a coastal aquifer adjacent to a stratified water body

    Science.gov (United States)

    Oz, Imri; Yechieli, Yoseph; Eyal, Shalev; Gavrieli, Ittai; Gvirtzman, Haim

    2016-04-01

    The existence of a freshwater-saltwater interface and the circulation flow of saltwater beneath the interface is a well-known phenomenon found at coastal aquifers. This flow is a natural phenomenon that occurs due to density differences between fresh groundwater and the saltwater body. The goals of this research are to use analytical, numerical, and physical models in order to examine the configuration of the freshwater-saltwater interface and the density-driven flow patterns within a coastal aquifer adjacent to long-term stratified saltwater bodies (e.g. meromictic lake). Such hydrological systems are unique, as they consist of three different water types: the regional fresh groundwater, and low and high salinity brines forming the upper and lower water layers of the stratified water body, respectively. This research also aims to examine the influence of such stratification on hydrogeological processes within the coastal aquifer. The coastal aquifer adjacent to the Dead Sea, under its possible future meromictic conditions, serves as an ideal example to examine these processes. The results show that adjacent to a stratified saltwater body three interfaces between three different water bodies are formed, and that a complex flow system, controlled by the density differences, is created, where three circulation cells are developed. These results are significantly different from the classic circulation cell that is found adjacent to non-stratified water bodies (lakes or oceans). In order to obtain a more generalized insight into the groundwater behavior adjacent to a stratified water body, we used the numerical model to perform sensitivity analysis. The hydrological system was found be sensitive to three dimensionless parameters: dimensionless density (i.e. the relative density of the three water bodies'); dimensionless thickness (i.e. the ratio between the relative thickness of the upper layer and the whole thickness of the lake); and dimensionless flux. The results

  3. 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

  4. Ocean mixing beneath Pine Island Glacier Ice Shelf

    Science.gov (United States)

    Kimura, Satoshi; Dutrieux, Pierre; Jenkins, Adrian; Forryan, Alexander; Naveira Garabato, Alberto; Firing, Yvonne

    2016-04-01

    Ice shelves around Antarctica are vulnerable to increase in ocean-driven melting, with the melt rate depending on ocean temperature and strength of sub-ice-shelf-cavity circulations. We present repeated measurements of velocity, temperature, salinity, turbulent kinetic energy dissipation rate and thermal variance dissipation rate beneath Pine Island Glacier Ice Shelf, collected by CTD, ADCP and turbulence sensors mounted on an Autonomous Underwater Vehicle (AUV). The turbulence quantities measured by the AUV outside the ice shelf are in good agreement with ship-based measurements. The highest rate of turbulent kinetic energy dissipation is found near the grounding line, while its temporal fluctuation over seabed ridge within the cavity corresponds to the tidal fluctuation predicted in the Pine Island Bay to the west. The highest thermal variance dissipation rate is found when the AUV was 0.5 m away from the ice, and the thermal variance dissipation generally increases with decreasing distance between the AUV and ice.

  5. Similarity law of fluctuating pressure spectrum beneath hydraulic jump

    Institute of Scientific and Technical Information of China (English)

    LIAN JiJian; WANG JiMin; GU JinDe

    2008-01-01

    Similarity law is the conversion rule between model and prototype, on which a lot of research works have been done, with no agreement reached referring to the similarity law of fluctuating pressure fre-quency spectrum. Experimental data of peak frequency and dominant frequency range of fluctuating pressure spectrum beneath hydraulic jump obtained from serial models of scales 1:1, 1:2 and 1:5 are compared. As a result, similarity law of fluctuating pressure spectrum in the strongly rolling area agrees with the gravity law. As peak frequency and dominant frequencies of fluctuating pressures in hydraulic normalized spectrums of fluctuating pressures show that the similarity nearly agrees with the gravity law.

  6. Can slabs melt beneath forearcs in hot subduction zones?

    Science.gov (United States)

    Ribeiro, J.; Maury, R.; Gregoire, M.

    2015-12-01

    At subduction zones, thermal modeling predict that the shallow part of the downgoing oceanic crust (test the hypothesis that adakites are pristine slab melts. We find that adakites from Baja California and Philippines formed by two distinct petrogenetic scenarios. In Baja California, hydrous mantle melts mixed/mingled with high-pressure (HP) adakite-type, slab melts within a lower crustal (~30 km depth) magma storage region before stalling into the upper arc crust (~7-15 km depth). In contrast, in the Philippines, primitive mantle melts stalled and crystallized within lower and upper crustal magma storage regions to produce silica-rich melts with an adakitic signature. Thereby, slab melting is not required to produce an adakitic geochemical fingerprint in hot subduction zones. However, our results also suggest that the downgoing crust potentially melted beneath Baja California.

  7. Multicomponent seismic forward modeling of gas hydrates beneath the seafloor

    Institute of Scientific and Technical Information of China (English)

    Yang Jia-Jia; He Bing-Shou; Zhang Jian-Zhong

    2014-01-01

    We investigated the effect of microscopic distribution modes of hydrates in porous sediments, and the saturation of hydrates and free gas on the elastic properties of saturated sediments. We simulated the propagation of seismic waves in gas hydrate-bearing sediments beneath the seafloor, and obtained the common receiver gathers of compressional waves (P-waves) and shear waves (S-waves). The numerical results suggest that the interface between sediments containing gas hydrates and free gas produces a large-amplitude bottom-simulating reflector. The analysis of multicomponent common receiver data suggests that ocean-bottom seismometers receive the converted waves of upgoing P-and S-waves, which increases the complexity of the wavefield record.

  8. Assessment of managed aquifer recharge at Sand Hollow Reservoir, Washington County, Utah, updated to conditions through 2014

    Science.gov (United States)

    Marston, Thomas M.; Heilweil, Victor M.

    2016-09-08

    Sand Hollow Reservoir in Washington County, Utah, was completed in March 2002 and is operated primarily for managed aquifer recharge by the Washington County Water Conservancy District. From 2002 through 2014, diversions of about 216,000 acre-feet from the Virgin River to Sand Hollow Reservoir have allowed the reservoir to remain nearly full since 2006. Groundwater levels in monitoring wells near the reservoir rose through 2006 and have fluctuated more recently because of variations in reservoir stage and nearby pumping from production wells. Between 2004 and 2014, about 29,000 acre-feet of groundwater was withdrawn by these wells for municipal supply. In addition, about 31,000 acre-feet of shallow seepage was captured by French drains adjacent to the North and West Dams and used for municipal supply, irrigation, or returned to the reservoir. From 2002 through 2014, about 127,000 acre-feet of water seeped beneath the reservoir to recharge the underlying Navajo Sandstone aquifer.Water quality continued to be monitored at various wells in Sand Hollow during 2013–14 to evaluate the timing and location of reservoir recharge as it moved through the aquifer. Changing geochemical conditions at monitoring wells WD 4 and WD 12 indicate rising groundwater levels and mobilization of vadose-zone salts, which could be a precursor to the arrival of reservoir recharge.

  9. Modelling the effects of tides and storm surges on coastal aquifers using a coupled surface-subsurface approach.

    Science.gov (United States)

    Yang, Jie; Graf, Thomas; Herold, Maria; Ptak, Thomas

    2013-06-01

    Coastal aquifers are complex hydrologic systems because many physical processes interact: (i) variably saturated flow, (ii) spatial-temporal fluid density variations, (iii) tidal fluctuations, (iv) storm surges overtopping dykes, and (v) surface runoff of storm water. The HydroGeoSphere model is used to numerically simulate coastal flow dynamics, assuming a fully coupled surface-subsurface approach, accounting for all processes listed above. The diffusive wave approximation of the St. Venant equation is used to describe surface flow. Surface flow and salt transport are fully coupled with subsurficial variably saturated, variable-density flow and salt transport through mathematical terms that represent exchange of fluid mass and solute mass, respectively. Tides and storm surges induce a time-variant head that is applied to nodes of the surface domain. The approach is applied to real cases of tide and storm surge events. Tide simulation results confirm the existence of a recirculating zone, forming beneath the upper part of the intertidal zone. By monitoring the exchange fluid flux rates through the beach, it was found that the major inflow to the aquifer takes place at the upper part of the intertidal zone, which explains the formation of the recirculating zone. The recirculating zone is forming particularly during rising tide. Results from a storm surge simulation show that plume fingers develop below the flooded land surface. Natural remediation by seaward flowing freshwater is relatively slow, such that reducing the salt concentration in the aquifer down to drinking water standards takes up to 10 years. PMID:23603354

  10. Numerical modelling to determine freshwater/saltwater interface configuration in a low-gradient coastal wetland aquifer

    Science.gov (United States)

    Swain, E.; Wolfert, M.

    2007-01-01

    A coupled hydrodynamic surface-water/groundwater model with salinity transport is used to examine the aquifer salinity interface in the coastal wetlands of Everglades National Park in Florida, USA. The hydrology differs from many other coastal areas in that inland water levels are often higher than land surface, the flow gradients are small, and, along parts of the coastline, the wetland is separated from the offshore waters by a natural embankment. Examining the model-simulated aquifer salinities along a transect that cuts the coastal embankment, a small zone of fresh groundwater is seen beneath the embankment, which varies seasonally in size and salinity. The simulated surface-water and groundwater levels suggest that this zone exists because of ponding of surface water at the coastal embankment, creating freshwater underflow to the offshore waters. The seasonal variability in the freshwater zone indicates that it is sensitive to the wetland flows and water levels. The small size of the zone in the simulation indicates that a model with a higher spatial resolution could probably depict the zone more accurately. The coastal ecology is strongly affected by the salinity of the shallow groundwater and the coastal freshwater zone is sensitive to wetland flows and levels. In this environment, predicting the aquifer salinity interface in coastal wetlands is important in examining the effects of changing water deliveries associated with ecosystem restoration efforts.

  11. Crustal and uppermost mantle structure beneath the United States

    Science.gov (United States)

    Shen, Weisen; Ritzwoller, Michael H.

    2016-06-01

    This paper presents a new model of the shear velocity structure of the crust and uppermost mantle beneath the contiguous U.S. The model is based on more than a decade of USArray Transportable Array (TA) data across the U.S. and derives from a joint Bayesian Monte Carlo inversion of Rayleigh wave group and phase speeds determined from ambient noise and earthquakes, receiver functions, and Rayleigh wave ellipticity (H/V) measurements. Within the Bayesian inverse theoretic framework, a prior distribution of models is posited and a posterior distribution is inferred beneath all of the more than 1800 TA stations across the U.S. The resulting mean and standard deviation of the mean of the posterior distribution at each station summarize the inversion results, which are then interpolated onto a regular 0.25°×0.25° grid across the U.S. to define the final 3-D model. We present arguments that show that the standard deviation of the posterior distribution overestimates the effect of nonsystematic errors in the final model by a factor of 4-5 and identify uncertainties in density and mantle Q as primary potential sources of remaining systematic error in the final model. The model presents a great many newly resolved structural features across the U.S. that require further analysis and dedicated explication. We highlight here low-velocity anomalies in the upper mantle that underlie the Appalachians with centers of anomalies in northern Georgia, western Virginia, and, most prominently, New England.

  12. Magma heating by decompression-driven crystallization beneath andesite volcanoes.

    Science.gov (United States)

    Blundy, Jon; Cashman, Kathy; Humphreys, Madeleine

    2006-09-01

    Explosive volcanic eruptions are driven by exsolution of H2O-rich vapour from silicic magma. Eruption dynamics involve a complex interplay between nucleation and growth of vapour bubbles and crystallization, generating highly nonlinear variation in the physical properties of magma as it ascends beneath a volcano. This makes explosive volcanism difficult to model and, ultimately, to predict. A key unknown is the temperature variation in magma rising through the sub-volcanic system, as it loses gas and crystallizes en route. Thermodynamic modelling of magma that degasses, but does not crystallize, indicates that both cooling and heating are possible. Hitherto it has not been possible to evaluate such alternatives because of the difficulty of tracking temperature variations in moving magma several kilometres below the surface. Here we extend recent work on glassy melt inclusions trapped in plagioclase crystals to develop a method for tracking pressure-temperature-crystallinity paths in magma beneath two active andesite volcanoes. We use dissolved H2O in melt inclusions to constrain the pressure of H2O at the time an inclusion became sealed, incompatible trace element concentrations to calculate the corresponding magma crystallinity and plagioclase-melt geothermometry to determine the temperature. These data are allied to ilmenite-magnetite geothermometry to show that the temperature of ascending magma increases by up to 100 degrees C, owing to the release of latent heat of crystallization. This heating can account for several common textural features of andesitic magmas, which might otherwise be erroneously attributed to pre-eruptive magma mixing.

  13. Estimating specific yield and storage change in an unconfined aquifer using temporal gravity surveys

    Science.gov (United States)

    Gehman, Carter L.; Harry, Dennis L.; Sanford, William E.; Stednick, John D.; Beckman, Nathaniel A.

    2009-04-01

    Two high-precision gravity surveys were conducted to determine groundwater mass changes at a managed groundwater recharge site in northeastern Colorado. Gravity data were collected during pumping and two months after pumping ceased. During pumping, gravity was lower by as much as 46 μGal near the pumping wells and higher by as much as 90 μGal near the recharge ponds in comparison to data collected after pumping had ceased. These differences are attributed to changes in groundwater mass associated with drawdown and infiltration. Inverse modeling of the gravity data indicates a 5.1 × 105 m3 decrease in storage beneath the recharge ponds between the two surveys, which we attribute to dissipation of the groundwater mound created by recharge during pumping. This estimate of the change in groundwater storage is made independently of assumptions of physical properties of the aquifer. Dividing the change in water volume per unit area determined from the gravity modeling by the change in water level measured in wells provides an estimate of specific yield (Sy) of 0.21 ± 0.03, which is within the range of specific yield estimates derived from aquifer tests at the site. Water level changes predicted from the gravity data agree on average to within ±0.45 m of those measured, which we take to be an estimate of the uncertainty in water table depth predictions that can be obtained from gravimetric data in unconfined aquifers. The study covers a 3.2 km2 area, providing a prototype for similar studies at larger scales.

  14. Evaluation of Four Water Management Policies for Ogallala Aquifer Sustainability in the Texas High Plains

    Science.gov (United States)

    Hernandez, J. E.; Gowda, P. H.; Howell, T. A.; Marek, T. H.; Ha, W.; Almas, L. K.

    2010-12-01

    Diminishing groundwater supply in the Ogallala Aquifer will severely reduce regional crop and animal production in the absence of a sustainable water management policy. It is essential to mitigate adverse impacts on the regional economy due to future withdrawals of the limited groundwater resource. Currently, approximately ten alternative water management policies are being debated by policy makers in the Central and Southern High Plains of the Ogallala Aquifer region. Before implementing any new policy or modifying current policies, newer alternative policies should be evaluated for their impact on groundwater levels with eventual extension to regional economic impacts. The main objective of this study was to evaluate four water management policies, from the debated ones, on future groundwater levels in the Ogallala Aquifer beneath four heavily irrigated counties (Dallam, Sherman, Hartley, and Moore) located in the northwest corner of the Texas High Plains using a calibrated ModFlow model. The four water management policies were (1) voluntary permanent conversion to dry land production up to 10% of the total irrigated area, (2) adoption of advances in biotechnology that allow water use reductions at a rate of 1% per year up to 10% of current use, (3) mandatory water use reduction to decrease the total water pumped by 10% (volume per unit land area per year), and (4) voluntary temporary conversion to dry land production during 15 years for a maximum area of 10% of the total irrigated area. The water management policies were converted into water demand rates for ModFlow model inputs. Simulations were conducted for a 50-year (2010-2060) period. Preliminary results indicate that a combination of more than one policy will be required to produce a significant reduction in the current groundwater depletion rates.

  15. Water-level change, High Plains aquifer, 1980 to 1995

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents water-level change in the High Plains aquifer of the United States from 1980 to 1995, in feet. The High Plains aquifer underlies...

  16. Water-level change, High Plains aquifer, 2000 to 2005

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents water-level change in the High Plains aquifer of the United States from 2000 to 2005, in feet. The High Plains aquifer underlies...

  17. Water-level change, High Plains aquifer, 2005 to 2009

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents water-level change in the High Plains aquifer of the United States from 2005 to 2009, in feet. The High Plains aquifer underlies...

  18. Water-level change, High Plains aquifer, 1995 to 2000

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents water-level change in the High Plains aquifer of the United States from 1995 to 2000, in feet. The High Plains aquifer underlies...

  19. Snake River Plain Basin-fill aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the Snake River Plain aquifer system, which includes both the basaltic and basin-fill aquifers. This dataset does not...

  20. Aquifers of Alluvial and Glacial Origin - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the alluvial and glacial aquifers north of the southern-most line of glaciation. Aquifers are shown in the States of Maine,...

  1. Shallow ground-water quality beneath a major urban center: Denver, Colorado, USA

    Science.gov (United States)

    Bruce, B.W.; McMahon, P.B.

    1996-01-01

    A survey of the chemical quality of ground water in the unconsolidated alluvial aquifer beneath a major urban center (Denver, Colorado, USA) was performed in 1993 with the objective of characterizing the quality of shallow ground-water in the urban area and relating water quality to land use. Thirty randomly selected alluvial wells were each sampled once for a broad range of dissolved constituents. The urban land use at each well site was sub- classified into one of three land-use settings: residential, commercial, and industrial. Shallow ground-water quality was highly variable in the urban area and the variability could be related to these land-use setting classifications. Sulfate (SO4) was the predominant anion in most samples from the residential and commercial land-use settings, whereas bicarbonate (HCO3) was the predominant anion in samples from the industrial land-use setting, indicating a possible shift in redox conditions associated with land use. Only three of 30 samples had nitrate concentrations that exceeded the US national drinking-water standard of 10 mg l-1 as nitrogen, indicating that nitrate contamination of shallow ground water may not be a serious problem in this urban area. However, the highest median nitrate concentration (4.2 mg l-1) was in samples from the residential setting, where fertilizer application is assumed to be most intense. Twenty-seven of 30 samples had detectable pesticides and nine of 82 analyzed pesticide compounds were detected at low concentrations, indicating that pesticides are widely distributed in shallow ground water in this urban area. Although the highest median total pesticide concentration (0.17 ??g l-1) was in the commercial setting, the herbicides prometon and atrazine were found in each land-use setting. Similarly, 25 of 29 samples analyzed had detectable volatile organic compounds (VOCs) indicating these compounds are also widely distributed in this urban area. The total VOC concentrations in sampled wells

  2. Aquifer parameter estimation from surface resistivity data.

    Science.gov (United States)

    Niwas, Sri; de Lima, Olivar A L

    2003-01-01

    This paper is devoted to the additional use, other than ground water exploration, of surface geoelectrical sounding data for aquifer hydraulic parameter estimation. In a mesoscopic framework, approximated analytical equations are developed separately for saline and for fresh water saturations. A few existing useful aquifer models, both for clean and shaley sandstones, are discussed in terms of their electrical and hydraulic effects, along with the linkage between the two. These equations are derived for insight and physical understanding of the phenomenon. In a macroscopic scale, a general aquifer model is proposed and analytical relations are derived for meaningful estimation, with a higher level of confidence, of hydraulic parameter from electrical parameters. The physical reasons for two different equations at the macroscopic level are explicitly explained to avoid confusion. Numerical examples from existing literature are reproduced to buttress our viewpoint. PMID:12533080

  3. Genetic algorithms and aquifer parameter identification

    Institute of Scientific and Technical Information of China (English)

    LI Jing-sheng(李竞生); YAO Lei-hua(姚磊华); LI Yang(李杨)

    2003-01-01

    In order to identify aquifer parameter,authors develops an improved combinatorial method called best chromosome clone plus younger generation chromosome prepotency genetic algorithm (BCC-YGCP-GA), based on a decimal system simple genetic algorithm (SGA). The paper takes unsteady state flows in a two-dimensional, inhomogeneous, confined aquifer for a ideal model, and utilizes SGA and BCC-YGCP-GA coupled to finite element method for identifying aquifer hydraulic conductivity K1,K2,K3 and storage S1,S2,S3, respectively. It is shown from the result that GSA does not reach convergence with 100 generations, whereas convergence rate of BCC-YGCD-GA is very fast. Objective function value calculated by BCC-YGCD-GA is 0.001 29 with 100 generations, and hydraulic conductivity and storage of three zones are almost equal to the "true" values of ideal model.

  4. Modeling contaminant plumes in fractured limestone aquifers

    DEFF Research Database (Denmark)

    Mosthaf, Klaus; Brauns, Bentje; Fjordbøge, Annika Sidelmann;

    Determining the fate and transport of contaminant plumes from contaminated sites in limestone aquifers is important because they are a major drinking water resource. This is challenging because they are often heavily fractured and contain chert layers and nodules, resulting in a complex transport...... the established approaches of the equivalent porous medium, discrete fracture and dual continuum models. However, these modeling concepts are not well tested for contaminant plume migration in limestone geologies. Our goal was to develop and evaluate approaches for modeling the transport of dissolved contaminant...... plumes in fractured limestone aquifers in 3D and to test methods for determining the required flow and transport parameters. The models were compared for a contaminated site in Denmark, where a plume of dissolved PCE has migrated through a fractured limestone aquifer. Numerical modeling was used...

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. Characteristics of Fault Zones in Volcanic Rocks Near Yucca Flat, Nevada Test Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Donald Sweetkind; Ronald M. Drake II

    2007-11-27

    During 2005 and 2006, the USGS conducted geological studies of fault zones at surface outcrops at the Nevada Test Site. The objectives of these studies were to characterize fault geometry, identify the presence of fault splays, and understand the width and internal architecture of fault zones. Geologic investigations were conducted at surface exposures in upland areas adjacent to Yucca Flat, a basin in the northeastern part of the Nevada Test Site; these data serve as control points for the interpretation of the subsurface data collected at Yucca Flat by other USGS scientists. Fault zones in volcanic rocks near Yucca Flat differ in character and width as a result of differences in the degree of welding and alteration of the protolith, and amount of fault offset. Fault-related damage zones tend to scale with fault offset; damage zones associated with large-offset faults (>100 m) are many tens of meters wide, whereas damage zones associated with smaller-offset faults are generally a only a meter or two wide. Zeolitically-altered tuff develops moderate-sized damage zones whereas vitric nonwelded, bedded and airfall tuff have very minor damage zones, often consisting of the fault zone itself as a deformation band, with minor fault effect to the surrounding rock mass. These differences in fault geometry and fault zone architecture in surface analog sites can serve as a guide toward interpretation of high-resolution subsurface geophysical results from Yucca Flat.

  12. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-05-31

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

  14. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    DOE

    1986-05-01

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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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.

  2. 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

  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. Groundwater Mounding in Non-uniform Aquifers with Implications for Managed Aquifer Recharge

    Science.gov (United States)

    Zlotnik, V. A.; Noel, P.; Kacimov, A. R.; Al Maktoumi, A. K.

    2015-12-01

    Many areas of the world (e.g. the Middle East and North Africa countries) are deficient in observation networks and hydrogeological data needed for Managed Aquifer Recharge (MAR) design. Therefore, diagnostic analytical approaches are appropriate for feasibility studies of MAR. It was found that the common assumption of aquifer thickness uniformity often does not hold, especially in mountainous watersheds. However, the only practical result available for non-uniform aquifers was developed for well hydraulics applications (point sinks or sources) by Hantush (1962), while the recharge zones may cover large areas on the scale of kilometers, such as temporarily filled impoundments (natural and engineered reservoirs in wadis, depressions, trenches, etc.) or perennial streams accepting massive treated wastewater discharge. To address these important, but overlooked MAR problems in sloping aquifers, a set of new closed-form analytical solutions for water table elevations were obtained. Interestingly, the 2D groundwater flow equation acquires the advection-dispersion equation form in these cases. The quadratures in closed-form solutions obtained by the Green's function method converge rapidly. These models account for both shapes and orientations of sources with respect to the direction of the aquifer base gradient. Qualitatively, solutions in sloping aquifers have an important trait: the mounding is limited in time and space, unlike in aquifers with a horizontal base. Aquifers with the greater slopes have the lesser potential of waterlogging from the rising water table and different storage characteristics (height and volume of locally stored water). Computational aspects of these solutions for MAR analyses are illustrated by example utilizing regional aquifer properties near Az Zarqa River, Jordan. (This study was supported by a grant from USAID-FABRI, project contract: AID-OAA-TO-11-00049, Subcontract: 1001624 -12S-19745).

  5. Collecting a multi-disciplinary field dataset to model the interactions between a flood control reservoir and the underlying porous aquifer

    Science.gov (United States)

    Borgatti, L.; Corsini, A.; Chiapponi, L.; D'Oria, M.; Giuffredi, F.; Lancellotta, R.; Mignosa, P.; Moretti, G.; Orlandini, S.; Pellegrini, M.; Remitti, F.; Ronchetti, F.; Tanda, M.; Zanini, A.

    2008-12-01

    During the last decades, a large number of flood control reservoirs were developed in Northern Italy, in order to mitigate flood risk in urban areas. The city of Parma, located on the large alluvial fan of the Parma River, is served by a flood control reservoir (i.e., dry dam), completed in 2004. The reservoir can store a volume of 12·106 m3 over an area of 1.2 km2 surrounded by about 4 km of artificial levees and closed downstream by a concrete dam 15 m high, equipped with 3 movable floodgates. The structure has the purpose to store the excess water in the case of high return period flood events, releasing it downstream at a controlled rate. A stilling basin is located downstream the dam in order to dissipate the kinetic energy of the discharged flow. The stilling basin is made up of 2 m thick concrete slabs, on which 3 dissipating blocks are located. The deposits below the stilling basin are surrounded by a grout wall (20 m deep) with the aim of realizing a confined "box". Groundwater levels inside the box are controlled by a 110 m long drainage trench located upstream the stilling basin, 3 m below its floor. In the perspective of a long-term management of the reservoir, after the completion of the works, a phase of investigation, control and monitoring of the efficiency of the entire system has been carried out, mainly to highlight the interactions between the reservoir and the underlying aquifer. This task was accomplished filling the reservoir at the maximum retaining level by means of capturing the tails of spring 2008 flood events. The aquifer beneath and surrounding the structure has been investigated by means of several tests, such analysis. Moreover, a groundwater monitoring system made up by 44 piezometers with dataloggers and real- time data transmission to a dedicated website has been set up. Monitoring data before, during, and after the infilling of the reservoir show that the aquifer below the structure is multilayered, with prevailing silty gravels

  6. Unconsolidated Aquifers in Tompkins County, New York

    Science.gov (United States)

    Miller, Todd S.

    2000-01-01

    Unconsolidated aquifers consisting of saturated sand and gravel are capable of supplying large quantities of good-quality water to wells in Tompkins County, but little published geohydrologic inform ation on such aquifers is available. In 1986, the U.S.Geological Survey (USGS) began collecting geohydrologic information and well data to construct an aquifer map showing the extent of unconsolidated aquifers in Tompkins county. Data sources included (1) water-well drillers. logs; (2) highway and other construction test-boring logs; (3) well data gathered by the Tompkins County Department of Health, (4) test-well logs from geohydrologic consultants that conducted projects for site-specific studies, and (5) well data that had been collected during past investigations by the USGS and entered into the National Water Information System (NWIS) database. In 1999, the USGS, in cooperation with the Tompkins County Department of Planning, compiled these data to construct this map. More than 600 well records were entered into the NWIS database in 1999 to supplement the 350 well records already in the database; this provided a total of 950 well records. The data were digitized and imported into a geographic information system (GIS) coverage so that well locations could be plotted on a map, and well data could be tabulated in a digital data base through ARC/INFO software. Data on the surficial geology were used with geohydrologic data from well records and previous studies to delineate the extent of aquifers on this map. This map depicts (1) the extent of unconsolidated aquifers in Tompkins County, and (2) locations of wells whose records were entered into the USGS NWIS database and made into a GIS digital coverage. The hydrologic information presented here is generalized and is not intended for detailed site evaluations. Precise locations of geohydrologic-unit boundaries, and a description of the hydrologic conditions within the units, would require additional detailed, site

  7. Aquifer thermal energy storage. International symposium: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

    Aquifers have been used to store large quantities of thermal energy to supply process cooling, space cooling, space heating, and ventilation air preheating, and can be used with or without heat pumps. Aquifers are used as energy sinks and sources when supply and demand for energy do not coincide. Aquifer thermal energy storage may be used on a short-term or long-term basis; as the sole source of energy or as a partial storage; at a temperature useful for direct application or needing upgrade. The sources of energy used for aquifer storage are ambient air, usually cold winter air; waste or by-product energy; and renewable energy such as solar. The present technical, financial and environmental status of ATES is promising. Numerous projects are operating and under development in several countries. These projects are listed and results from Canada and elsewhere are used to illustrate the present status of ATES. Technical obstacles have been addressed and have largely been overcome. Cold storage in aquifers can be seen as a standard design option in the near future as it presently is in some countries. The cost-effectiveness of aquifer thermal energy storage is based on the capital cost avoidance of conventional chilling equipment and energy savings. ATES is one of many developments in energy efficient building technology and its success depends on relating it to important building market and environmental trends. This paper attempts to provide guidance for the future implementation of ATES. Individual projects have been processed separately for entry onto the Department of Energy databases.

  8. Unconfined Aquifer Flow Theory - from Dupuit to present

    OpenAIRE

    Mishra, Phoolendra K.; Kuhlman, Kristopher L.

    2013-01-01

    Analytic and semi-analytic solution are often used by researchers and practicioners to estimate aquifer parameters from unconfined aquifer pumping tests. The non-linearities associated with unconfined (i.e., water table) aquifer tests makes their analysis more complex than confined tests. Although analytical solutions for unconfined flow began in the mid-1800s with Dupuit, Thiem was possibly the first to use them to estimate aquifer parameters from pumping tests in the early 1900s. In the 195...

  9. In situ microcosms in aquifer bioremediation studies.

    Science.gov (United States)

    Mandelbaum, R T; Shati, M R; Ronen, D

    1997-07-01

    The extent to which aquifer microbiota can be studied under laboratory or simulated conditions is limited by our inability to authentically duplicate natural conditions in the laboratory. Therefore, extrapolation of laboratory results to real aquifer situations is often criticized, unless validation of the data is performed in situ. Reliable data acquisition is critical for the estimation of chemical and biological reaction rates of biodegradation processes in groundwater and as input data for mathematical models. Typically, in situ geobiochemical studies relied on the injection of groundwater spiked with compounds or bacteria of interest into the aquifer, followed by monitoring the changes over time and space. In situ microcosms provide a more confined study site for measurements of microbial reactions, yet closer to natural conditions than laboratory microcosms. Two basic types of in situ aquifer microcosm have been described in recent years, and both originated from in situ instruments initially designed for geochemical measurements. Gillham et al. [Ground Water 28 (1990) 858-862] constructed an instrument that isolates a portion of an aquifer for in situ biochemical rate measurements. More recently Shati et al. [Environ. Sci. Technol. 30 (1996) 2646-2653] modified a multilayer sampler for studying the activity of inoculated bacteria in a contaminated aquifer Keeping in mind recent advances in environmental microbiology methodologies such as immunofluorescence direct counts, oligonucleotide and PCR probes, fatty acid methyl esther analysis for the detection and characterization of bacterial communities, measurement of mRNA and expression of proteins, it is evident that much new information can now be gained from in situ work. Using in situ microcosms to study bioremediation efficiencies, the fate of introduced microorganisms and general geobiochemical aquifer processes can shed more realistic light on the microbial underworld. The aim of this paper is to

  10. Predicted nitrate and arsenic concentrations in basin-fill aquifers of the Southwest Principal Aquifers study area

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This product "Predicted nitrate and arsenic concentrations in basin-fill aquifers of the Southwest Principal Aquifers study area" is a 1:250,000-scale vector...

  11. EPA Region 6 Sole Source Aquifers in Louisiana, Geographic NAD83, EPA (1996) [sole_source_aquifers_LA_EPA_1996

    Data.gov (United States)

    Louisiana Geographic Information Center — Polygon layer of EPA Region 6 sole source aquifers in Louisiana. The sole source aquifers represented are Chicot and Southern Hills in Louisiana/Mississippi.

  12. Digital data sets that describe aquifer characteristics of the Vamoosa-Ada aquifer in east-central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized water-level elevation contours for the Vamoosa-Ada aquifer in east-central Oklahoma. The Vamoosa-Ada aquifer is an important...

  13. Digital data sets that describe aquifer characteristics of the Vamoosa-Ada aquifer in east-central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized polygons of constant hydraulic conductivity values for the Vamoosa-Ada aquifer in east-central Oklahoma. The Vamoosa-Ada aquifer...

  14. Digital data sets that describe aquifer characteristics of the Vamoosa-Ada aquifer in east-central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized polygons of constant recharge values for the Vamoosa-Ada aquifer, in east-central Oklahoma. The Vamoosa-Ada aquifer is an...

  15. Examples of transient sounding from groundwater exploration in sedimentary aquifers

    Science.gov (United States)

    Fitterman, D.V.

    1987-01-01

    Examples of the use of transient electromagnetic soundings for three groundwater exploration problems in sedimentary aquifers are given. The examples include: 1) estimating depths to water table and bedrock in an alluvium-filled basin, 2) mapping a confined freshwater aquifer in bedrock sediments, and 3) locating a freshwater/saltwater interface in a glacial-outwash aquifer. -from Author

  16. Review: The Yucatán Peninsula karst aquifer, Mexico

    DEFF Research Database (Denmark)

    Bauer-Gottwein, Peter; Gondwe, Bibi Ruth Neuman; Charvet, Guillaume;

    2011-01-01

    The Yucatán Peninsula karst aquifer is one of the most extensive and spectacular karst aquifer systems on the planet. This transboundary aquifer system extends over an area of approximately 165,000 km2 in México, Guatemala and Belize. The Triassic to Holocene Yucatán limestone platform is located...

  17. Groundwater modeling of the Calera Aquifer region in Central Mexico

    Science.gov (United States)

    The Calera Aquifer is the main source of water for irrigated agriculture, industrial, and drinking water purposes in the Calera Aquifer Region (CAR) in the state of Zacatecas, Mexico. Irrigated agriculture accounts for 80% of the total groundwater extracted from the Calera Aquifer. In recent years, ...

  18. 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

  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. 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.

  1. 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.

  2. 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

  3. Electrical conductivity anomaly beneath Mare Serenitatis detected by Lunokhod 2 and Apollo 16 magnetometers

    Science.gov (United States)

    Vanian, L. L.; Vnuchkova, T. A.; Egorov, I. V.; Basilevskii, A. T.; Eroshenko, E. G.; Fainberg, E. B.; Dyal, P.; Daily, W. D.

    1979-01-01

    Magnetic fluctuations measured by the Lunokhod 2 magnetometer in the Bay Le Monnier are distinctly anisotropic when compared to simultaneous Apollo 16 magnetometer data measured 1100 km away in the Descartes highlands. This anisotropy can be explained by an anomalous electrical conductivity of the upper mantle beneath Mare Serenitatis. A model is presented of anomalously lower electrical conductivity beneath Serenitatis and the simultaneous magnetic data from the Lunokhod 2 site at the mare edge and the Apollo 16 site are compared to the numerically calculated model solutions. This comparison indicates that the anisotropic fluctuations can be modeled by a nonconducting layer in the lunar lithosphere which is 150 km thick beneath the highlands and 300 km thick beneath Mare Serenitatis. A decreased electrical conductivity in the upper mantle beneath the mare may be due to a lower temperature resulting from heat carried out the magma source regions to the surface during mare flooding.

  4. Aquifer geochemistry at potential aquifer storage and recovery sites in coastal plain aquifers in the New York city area, USA

    Science.gov (United States)

    Brown, C.J.; Misut, P.E.

    2010-01-01

    The effects of injecting oxic water from the New York city (NYC) drinking-water supply and distribution system into a nearby anoxic coastal plain aquifer for later recovery during periods of water shortage (aquifer storage and recovery, or ASR) were simulated by a 3-dimensional, reactive-solute transport model. The Cretaceous aquifer system in the NYC area of New York and New Jersey, USA contains pyrite, goethite, locally occurring siderite, lignite, and locally varying amounts of dissolved Fe and salinity. Sediment from cores drilled on Staten Island and western Long Island had high extractable concentrations of Fe, Mn, and acid volatile sulfides (AVS) plus chromium-reducible sulfides (CRS) and low concentrations of As, Pb, Cd, Cr, Cu and U. Similarly, water samples from the Lloyd aquifer (Cretaceous) in western Long Island generally contained high concentrations of Fe and Mn and low concentrations of other trace elements such as As, Pb, Cd, Cr, Cu and U, all of which were below US Environmental Protection Agency (USEPA) and NY maximum contaminant levels (MCLs). In such aquifer settings, ASR operations can be complicated by the oxidative dissolution of pyrite, low pH, and high concentrations of dissolved Fe in extracted water.The simulated injection of buffered, oxic city water into a hypothetical ASR well increased the hydraulic head at the well, displaced the ambient groundwater, and formed a spheroid of injected water with lower concentrations of Fe, Mn and major ions in water surrounding the ASR well, than in ambient water. Both the dissolved O2 concentrations and the pH of water near the well generally increased in magnitude during the simulated 5-a injection phase. The resultant oxidation of Fe2+ and attendant precipitation of goethite during injection provided a substrate for sorption of dissolved Fe during the 8-a extraction phase. The baseline scenario with a low (0.001M) concentration of pyrite in aquifer sediments, indicated that nearly 190% more water

  5. Development of a three-dimensional ground-water model of the Hanford Site unconfined aquifer system: FY 1995 status report

    International Nuclear Information System (INIS)

    A three-dimensional numerical model of ground-water flow was developed for the uppermost unconfined aquifer at the Hanford Site in south-central Washington. Development of the model is supported by the Hanford Site Ground-Water Surveillance Project, managed by the Pacific Northwest National Laboratory, which is responsible for monitoring the sitewide movement of contaminants in ground water beneath the Hanford Site. Two objectives of the Ground-Water Surveillance Project are to (1) identify and quantify existing, emerging, or potential ground-water quality problems, and (2) assess the potential for contaminants to migrate from the Hanford Site through the ground-water pathway. Numerical models of the ground-water flow system are important tools for estimating future aquifer conditions and predicting the movement of contaminants through ground water. The Ground-Water Surveillance Project has supported development and maintenance of a two-dimensional model of the unconfined aquifer. This report describes upgrade of the two-dimensional model to a three-dimensional model. The numerical model is based on a three-dimensional conceptual model that will be continually refined and updated as additional information becomes available. This report presents a description of the three-dimensional conceptual model of ground-water flow in the unconfined aquifer system and then discusses the cur-rent state of the three-dimensional numerical model

  6. Transport and transformations of chlorinated-solvent contamination in a saprolite and fractured rock aquifer near a former wastewater-treatment plant, Greenville, South Carolina

    Science.gov (United States)

    Vroblesky, D.A.; Bradley, P.M.; Lane, J.W.; Robertson, J.F.

    1997-01-01

    The transport and fate of chlorinated-ethene contamination was investigated in a fractured-rock aquifer downgradient from a wastewater-treatment plant at a gas-turbine manufacturing facility inGreenville, South Carolina. A vapor-diffusion- sampler technique, developed for this investigation, located fracture zones that discharged contaminated ground water to surface water. The distribution ofchlorinated compounds and sulfate, comparison of borehole geophysical data, driller's logs, and the aquifer response to pumpage allowed subsurface contaminant-transport pathways to be delineated.The probable contaminant-transport pathway from the former aeration lagoon was southward. The probable pathway of contaminant transport from the former sludge lagoon was southward to and beneath Little Rocky Creek. South of the creek, the major pathway of contaminant transport appeared to be at a depth of approximately 80 to 107 feet below land surface. The contaminant-transport pathway from the former industrial lagoon was not readily discernible from existing data. A laboratory investigation, as well as examination of ground- water-chemistry data collected during this investigation and concentrations of chlorinated compounds collected during previous investigations,indicates that higher chlorinated compounds are being degraded to lower-chlorinated compounds in the contaminated aquifer. The approaches used in this investigation, as well as the findings, havepotential application to other fractured-rock aquifers contaminated by chlorinated ethenes.

  7. Digital data sets that describe aquifer characteristics of the Enid isolated terrace aquifer in northwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of a digitized polygon of a constant recharge value for the Enid isolated terrace aquifer in northwestern Oklahoma. The Enid isolated terrace...

  8. Digital data sets that describe aquifer characteristics of the Enid isolated terrace aquifer in northwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized polygons of constant hydraulic conductivity values for the Enid isolated terrace aquifer in northwestern Oklahoma. The Enid...

  9. Digital data sets that describe aquifer characteristics of the Rush Springs aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized polygons of constant recharge values for the Rush Springs aquifer in western Oklahoma. This area encompasses all or part of...

  10. Digital data sets that describe aquifer characteristics of the Central Oklahoma aquifer in central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized water-level elevation contours for the Central Oklahoma aquifer in central Oklahoma. This area encompasses all or part of...

  11. Denitrification in a deep basalt aquifer: implications for aquifer storage and recovery.

    Science.gov (United States)

    Nelson, Dennis; Melady, Jason

    2014-01-01

    Aquifer storage and recovery (ASR) can provide a means of storing water for irrigation in agricultural areas where water availability is limited. A concern, however, is that the injected water may lead to a degradation of groundwater quality. In many agricultural areas, nitrate is a limiting factor. In the Umatilla Basin in north central Oregon, shallow alluvial groundwater with elevated nitrate-nitrogen of 9 mg/L is injected into the Columbia River Basalt Group (CRBG), a transmissive confined aquifer(s) with low natural recharge rates. Once recovery of the injected water begins, however, NO3 -N in the recovered water decreases quickly to  +50, and correlate inversely with NO3 -N concentrations. This variation occurs in basalt aquifer, averaging 3.0 mg/L. Similar to nitrate concentrations, TOC drops in the recovered water, consistent with this component contributing to the denitrification of nitrate during storage.

  12. State Aquifer Recharge Atlas Plates, Geographic NAD83, LDEQ (1999) [aquifer_recharge_potential_LDEQ_1988

    Data.gov (United States)

    Louisiana Geographic Information Center — This is a polygon dataset depicting the boundaries of aquifer systems in the state of Louisiana and adjacent areas of Texas, Arkansas and a portion of Mississippi....

  13. Digital data sets that describe aquifer characteristics of the Rush Springs aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized polygons of constant hydraulic conductivity values for the Rush Springs aquifer in western Oklahoma. This area encompasses all...

  14. Digital data sets that describe aquifer characteristics of the Antlers aquifer in southeastern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized polygons of a constant hydraulic conductivity value for the Antlers aquifer in southeastern Oklahoma. The Early Cretaceous-age...

  15. Digital data sets that describe aquifer characteristics of the Antlers aquifer in southeastern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized water-level elevation contours for the Antlers aquifer in southeastern Oklahoma. The Early Cretaceous-age Antlers Sandstone is...

  16. Digital data sets that describe aquifer characteristics of the High Plains aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of constant hydraulic conductivity values for the High Plains aquifer in Oklahoma. This area encompasses the panhandle...

  17. Digital data sets that describe aquifer characteristics of the Central Oklahoma aquifer in central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized polygons of a constant recharge value for the Central Oklahoma aquifer in central Oklahoma. This area encompasses all or part of...

  18. Digital data sets that describe aquifer characteristics of the High Plains aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized water-level elevation contours for the High Plains aquifer in western Oklahoma. This area encompasses the panhandle counties of...

  19. Digital data sets that describe aquifer characteristics of the High Plains aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of constant recharge rates for the High Plains aquifer in Oklahoma. This area encompasses the panhandle counties of...

  20. Digital data sets that describe aquifer characteristics of the Central Oklahoma aquifer in central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized polygons of a constant hydraulic conductivity value for the Central Oklahoma aquifer in central Oklahoma. This area encompasses...