A5029735393- Groundwater flow and contamination studies
- Nuclear and radioactivity studies
- Graphite, nuclear technology, radiation studies
- Soil and Unsaturated Flow
- Groundwater and Isotope Geochemistry
- Geophysical Methods and Applications
- Hydraulic Fracturing and Reservoir Analysis
- Radioactive contamination and transfer
- Risk and Safety Analysis
- Geophysical and Geoelectrical Methods
- Landslides and related hazards
- Reservoir Engineering and Simulation Methods
- Geological Modeling and Analysis
- Water Systems and Optimization
- Rock Mechanics and Modeling
- Water Quality and Resources Studies
- 3D Surveying and Cultural Heritage
- Radioactive element chemistry and processing
- Archaeology and Natural History
- Soil erosion and sediment transport
- CO2 Sequestration and Geologic Interactions
- Flow Measurement and Analysis
- Radioactivity and Radon Measurements
- NMR spectroscopy and applications
- Flood Risk Assessment and Management
Los Alamos National Laboratory
2005-2024
Los Alamos Medical Center
1994
University of Colorado Boulder
1988
Abstract A light‐extinction principle was used to measure the fall speeds of interfaces that develop during gravity sedimentation monodisperse, bidisperse, and tridisperse suspensions noncolloidal particles with small particle Reynolds numbers in semidilute total volume fraction range 0.0003 ⩽ c 0 0.15. For monodisperse suspensions, hindered settling velocity interface at top suspension found be well represented by correlation Richardson Zaki, provided isolated speed chosen linear...
Reduction of toxic Cr(VI) to less Cr(III) is an important process for attenuating transport in groundwater. This results immobilization chromium as and effectively decreases the overall mobility inventory. During both abiotic biotic reduction Cr(III), a kinetic isotope effect occurs which lighter isotope, 52Cr, reacts preferentially, leaving remaining dissolved enriched heavier 53Cr. Cr isotopes have proven be useful tool estimating magnitude determining where hydrologic system occurring. In...
The Pajarito Plateau in northern New Mexico, on which the Los Alamos National Laboratory is situated, characterized by a thick vadose zone overlying regional aquifer of western Espanola Basin. In this study, conceptual models flow and transport processes are presented then supported through interpretation field data, including synthesis with numerical models. differentiate rate percolation their location surface hydrologic setting, wet dry canyons, wet, dry, disturbed mesas. Net infiltration...
Using new and previously published estimates of point infiltration in upland areas stream‐flow losses gains along canyon bottoms, we created a map net for the Los Alamos area, New Mexico pre‐Cerro Grande fire period. The are based on combination techniques that include use Richards equation, chloride mass‐balance method, numerical modeling. rates estimated with these were extrapolated to uncharacterized parts study area using maps environmental variables correlated (such as topography,...
A conceptual model is developed to better understand vadose zone vapor‐phase diffusion within the mesas of Pajarito Plateau at Los Alamos National Laboratory. We focus on 1,1,1‐trichloroethane (TCA) vapor transport from a liquid‐waste disposal site. The incorporates several physical processes, including partitioning TCA into liquid phase, saturation‐dependent diffusion, through asphalt, and interaction with atmosphere. Three‐dimensional numerical simulations that use are then calibrated...
A numerical study of a single fracture embedded in porous matrix was performed to investigate the role coatings and fills on water movement permeable, fractured media. The variables considered were conductivity continuity coatings; location, length, fills; combinations initial saturation; inflow boundary conditions. Results from simulations indicate that low‐saturation, high‐capillarity tuff systems, conditions under which fractures act as rapid flow paths are limited. These include...
Core Ideas Soil vapor extraction (SVE) wells are an effective interim remediation technique. Flow and transport modeling assists in evaluation of plume behavior. Plume simulations assuming drum failure SVE provide a framework for planning. A small borehole subset could be monitored detection VOC releases due to failure. has been used at sites across the Department Energy complex, including where legacy subsurface wastes represent potential source groundwater contamination. At Los Alamos...
Core Ideas Permeability contrasts in layered rocks can result perched water and lateral flow. Diversion of above the testing horizon slows downward transport radionuclides. Permeable within saturated lower permeability remain unsaturated. Sixty‐one underground nuclear tests were conducted at Rainier Mesa Nevada National Security Site between 1957 1992. The mesa includes highest‐elevation areas experiences some highest estimated infiltration rates. Perched is ubiquitous many tunnels used for...
Long-term environmental performance assessments of natural processes, including erosion, are critically important for waste repository site evaluation. However, assessing a site’s ability to continuously function is challenging due parameter uncertainty and compounding nonlinear processes. In lieu unavailable data model calibration, we present workflow include multiple sources surrogate reduced-order models validate parameters long-term erosion assessment low-level radioactive nuclear...
We present an analysis and interpretation of potential cliff stability at a low-level waste disposal facility Los Alamos National Laboratory, New Mexico, using morphologic fracture characteristics coupled with carbon-14 surface exposure dating. Our study is important as it directly bears on the licensing criteria for radioactive sites. find that future characteristic failures will likely not breach pits shafts over 1000-year minimum regulatory period. Further, we find, multivariate...
Vadose zone transport of tritium and nitrate can be important considerations at radioactive waste sites, landfills, or areas with industrial impacts. These contaminants are particular concern because they typically have a relatively higher mobility in the subsurface compared to other compounds. Here, we describe semiarid site contamination involving manmade ponded water source above thick unsaturated Los Alamos National Laboratory New Mexico, USA. This study demonstrates value vadose flow...