Cores from two of the 13 U.S. Geological Survey (USGS) research holes at Yellowstone National Par... more Cores from two of the 13 U.S. Geological Survey (USGS) research holes at Yellowstone National Park (Y-5 and Y-8) were evaluated to characterize lithology, texture, alteration, and the degree and nature of fracturing and veining. Matrix permeability measurements and petrographic examination of the core were used to evaluate the effects of lithology and hydrothermal alteration on permeability. The intervals studied in these two core holes span the conductive zone (including the reservoir cap) and the upper portion of the convective geothermal reservoir. Variations in porosity and matrix permeability observed in the Y-5 and Y-8 cores are primarily controlled by lithology. Y-8 intersects three distinct lithologies: volcaniclastic sandstone, perlitic rhyolite lava, and nonwelded pumiceous ash flow tuff. The sandstone typically has high permeability and porosity, and the tuff has very high porosity and moderate permeability, while the perlitic lava has very low porosity and is essentially...
A major effort of site characterization activities at Yucca Mountain, Nevada, a site being studie... more A major effort of site characterization activities at Yucca Mountain, Nevada, a site being studied by the U.S. Department of Energy (DOE) as a potential repository of high-level radioactive waste, is directed toward understanding the efficacy of the natural barrier to isolate waste. Characterization of potential aqueous radionuclide migration from waste containers to the accessible environment, a distance of 5 km, is a key step in that determination because of regulations which stipulate that the site must be able to isolate waste for 10,000 years. The Yucca Mountain Site Characterization Project (YMP) has an integrated radionuclide migration program that combines investigations to characterize processes that affect radionuclide transport, including solubility, speciation, sorption, diffusion, and dispersion, and studies to investigate aspects of the natural system affecting those processes, such as mineralogy, mineral stability, and water chemistry. The program also includes studie...
Level 4 Milestone SPY289M4 June 30,1998 Version 1.0 Yucca Mountain Site Characterization Project ... more Level 4 Milestone SPY289M4 June 30,1998 Version 1.0 Yucca Mountain Site Characterization Project Thermo-Hydro-Chemical Predictive Analysis For The Drift-Scale Heater Test Eric Sonnenthal, Nicolas Spycher, John Apps, and Ardyth Simmons Lawrence Berkeley National laboratory FRACTURE LOG PC0 : 2 MONTHS LOG PCO, Earth Sciences Division Lawrence Berkeley National Laboratory One Cyclotron Road M S 90-1116 Berkeley, C A 94720
APPLICATION OF NATURAL ANALOGUES IN THE YUCCA MOUNTAIN PROJECT - OVERVIEW Ardyth M. Simmons, Lawr... more APPLICATION OF NATURAL ANALOGUES IN THE YUCCA MOUNTAIN PROJECT - OVERVIEW Ardyth M. Simmons, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (amsimmons@lbl.gov) 1. INTRODUCTION The Natural Analogue Synthesis Report (NASR) [1] provides a compilation of information from analogues that test, corroborate, and add confidence to process models and model predictions pertinent to total system performance assessment (TSPA). The report updated previous work [2] with new literature examples and results of quantitative studies conducted by the Yucca Mountain Project (YMP). The intent of the natural analogue studies was to collect corroborative evidence from analogues to demonstrate greater understanding of processes expected to occur during postclosure of a proposed Yucca Mountain repository. Natural analogues, as used here, refer to either natural or anthropogenic systems in which processes similar to those expected to occur in a nuclear waste repository are thought to have occurred ...
The U.S. concept for permanent disposal of high-level radioactive waste resembles those of other ... more The U.S. concept for permanent disposal of high-level radioactive waste resembles those of other countries in that it relies upon burial in a deep geologic medium. This concept relies upon multiple barriers to retard transport of radionuclides to the accessible environment; those barriers consist of the waste form, waste container, engineered barrier system (including possible backfill) and retardant properties of the host rock. Because mobilization of radionuclides is fundamentally a geochemical problem, an understanding of past, present, and future geochemical processes is a requisite part of site characterization studies conducted by the U.S. Department of Energy at Yucca Mountain, Nevada. Geochemical information is needed for evaluating three favorable conditions (the rates of geochemical processes, conditions that promote precipitation or sorption of radionuclides or prohibit formation of colloids, and stable mineral assemblages) and four potentially adverse conditions of the s...
We use uranium (U) isotope ratios to detect and quantify the extent of natural U reduction in gro... more We use uranium (U) isotope ratios to detect and quantify the extent of natural U reduction in groundwater across a roll front redox gradient. Our study was conducted at the Smith Ranch-Highland in situ recovery (ISR) U mine in eastern Wyoming, USA, where economic U deposits occur in the Paleocene Fort Union formation. To evaluate the fate of aqueous U in and adjacent to the ore body, we investigated the chemical composition and isotope ratios of groundwater samples from the roll-front type ore body and surrounding monitoring wells of a previously mined area. The (238)U/(235)U of groundwater varies by approximately 3‰ and is correlated with U concentrations. Fluid samples down-gradient of the ore zone are the most depleted in (238)U and have the lowest U concentrations. Activity ratios of (234)U/(238)U are ∼5.5 up-gradient of the ore zone, ∼1.0 in the ore zone, and between 2.3 and 3.7 in the down-gradient monitoring wells. High-precision measurements of (234)U/(238)U and (238)U/(235)...
Field mapping has produced a preliminary picture of Mohon Mountain as a composite volcano, in whi... more Field mapping has produced a preliminary picture of Mohon Mountain as a composite volcano, in which pyroclastic ash and larger tephra erupted alternately with flows of rhyodacite and dacite. An analog study which uses imagery of lunar and Martian features will compare the overall shape of the vent complex, including its breached southern flank and satellite vents, to similar landforms
This session will explore the current technical approaches to reducing the environmental effects ... more This session will explore the current technical approaches to reducing the environmental effects of uranium ISR in comparison to the historical environmental impact of uranium mining to demonstrate advances in this controversial subject.
Cores from two of the 13 U.S. Geological Survey (USGS) research holes at Yellowstone National Par... more Cores from two of the 13 U.S. Geological Survey (USGS) research holes at Yellowstone National Park (Y-5 and Y-8) were evaluated to characterize lithology, texture, alteration, and the degree and nature of fracturing and veining. Matrix permeability measurements and petrographic examination of the core were used to evaluate the effects of lithology and hydrothermal alteration on permeability. The intervals studied in these two core holes span the conductive zone (including the reservoir cap) and the upper portion of the convective geothermal reservoir. Variations in porosity and matrix permeability observed in the Y-5 and Y-8 cores are primarily controlled by lithology. Y-8 intersects three distinct lithologies: volcaniclastic sandstone, perlitic rhyolite lava, and nonwelded pumiceous ash flow tuff. The sandstone typically has high permeability and porosity, and the tuff has very high porosity and moderate permeability, while the perlitic lava has very low porosity and is essentially...
A major effort of site characterization activities at Yucca Mountain, Nevada, a site being studie... more A major effort of site characterization activities at Yucca Mountain, Nevada, a site being studied by the U.S. Department of Energy (DOE) as a potential repository of high-level radioactive waste, is directed toward understanding the efficacy of the natural barrier to isolate waste. Characterization of potential aqueous radionuclide migration from waste containers to the accessible environment, a distance of 5 km, is a key step in that determination because of regulations which stipulate that the site must be able to isolate waste for 10,000 years. The Yucca Mountain Site Characterization Project (YMP) has an integrated radionuclide migration program that combines investigations to characterize processes that affect radionuclide transport, including solubility, speciation, sorption, diffusion, and dispersion, and studies to investigate aspects of the natural system affecting those processes, such as mineralogy, mineral stability, and water chemistry. The program also includes studie...
Level 4 Milestone SPY289M4 June 30,1998 Version 1.0 Yucca Mountain Site Characterization Project ... more Level 4 Milestone SPY289M4 June 30,1998 Version 1.0 Yucca Mountain Site Characterization Project Thermo-Hydro-Chemical Predictive Analysis For The Drift-Scale Heater Test Eric Sonnenthal, Nicolas Spycher, John Apps, and Ardyth Simmons Lawrence Berkeley National laboratory FRACTURE LOG PC0 : 2 MONTHS LOG PCO, Earth Sciences Division Lawrence Berkeley National Laboratory One Cyclotron Road M S 90-1116 Berkeley, C A 94720
APPLICATION OF NATURAL ANALOGUES IN THE YUCCA MOUNTAIN PROJECT - OVERVIEW Ardyth M. Simmons, Lawr... more APPLICATION OF NATURAL ANALOGUES IN THE YUCCA MOUNTAIN PROJECT - OVERVIEW Ardyth M. Simmons, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (amsimmons@lbl.gov) 1. INTRODUCTION The Natural Analogue Synthesis Report (NASR) [1] provides a compilation of information from analogues that test, corroborate, and add confidence to process models and model predictions pertinent to total system performance assessment (TSPA). The report updated previous work [2] with new literature examples and results of quantitative studies conducted by the Yucca Mountain Project (YMP). The intent of the natural analogue studies was to collect corroborative evidence from analogues to demonstrate greater understanding of processes expected to occur during postclosure of a proposed Yucca Mountain repository. Natural analogues, as used here, refer to either natural or anthropogenic systems in which processes similar to those expected to occur in a nuclear waste repository are thought to have occurred ...
The U.S. concept for permanent disposal of high-level radioactive waste resembles those of other ... more The U.S. concept for permanent disposal of high-level radioactive waste resembles those of other countries in that it relies upon burial in a deep geologic medium. This concept relies upon multiple barriers to retard transport of radionuclides to the accessible environment; those barriers consist of the waste form, waste container, engineered barrier system (including possible backfill) and retardant properties of the host rock. Because mobilization of radionuclides is fundamentally a geochemical problem, an understanding of past, present, and future geochemical processes is a requisite part of site characterization studies conducted by the U.S. Department of Energy at Yucca Mountain, Nevada. Geochemical information is needed for evaluating three favorable conditions (the rates of geochemical processes, conditions that promote precipitation or sorption of radionuclides or prohibit formation of colloids, and stable mineral assemblages) and four potentially adverse conditions of the s...
We use uranium (U) isotope ratios to detect and quantify the extent of natural U reduction in gro... more We use uranium (U) isotope ratios to detect and quantify the extent of natural U reduction in groundwater across a roll front redox gradient. Our study was conducted at the Smith Ranch-Highland in situ recovery (ISR) U mine in eastern Wyoming, USA, where economic U deposits occur in the Paleocene Fort Union formation. To evaluate the fate of aqueous U in and adjacent to the ore body, we investigated the chemical composition and isotope ratios of groundwater samples from the roll-front type ore body and surrounding monitoring wells of a previously mined area. The (238)U/(235)U of groundwater varies by approximately 3‰ and is correlated with U concentrations. Fluid samples down-gradient of the ore zone are the most depleted in (238)U and have the lowest U concentrations. Activity ratios of (234)U/(238)U are ∼5.5 up-gradient of the ore zone, ∼1.0 in the ore zone, and between 2.3 and 3.7 in the down-gradient monitoring wells. High-precision measurements of (234)U/(238)U and (238)U/(235)...
Field mapping has produced a preliminary picture of Mohon Mountain as a composite volcano, in whi... more Field mapping has produced a preliminary picture of Mohon Mountain as a composite volcano, in which pyroclastic ash and larger tephra erupted alternately with flows of rhyodacite and dacite. An analog study which uses imagery of lunar and Martian features will compare the overall shape of the vent complex, including its breached southern flank and satellite vents, to similar landforms
This session will explore the current technical approaches to reducing the environmental effects ... more This session will explore the current technical approaches to reducing the environmental effects of uranium ISR in comparison to the historical environmental impact of uranium mining to demonstrate advances in this controversial subject.
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