Volatilities of the Fission Product and Uranium Oxides

Bedford, R.G.; Jackson, Donald Dale

doi:10.2172/4638956

Cited by 17 publications

(14 citation statements)

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“…For those nuclides with no specific literature reference, volatilities of oxides (Bedford and Jackson, 1965;Kirkorian, 1981) and melting point temperatures were used to assign a behavior consistent with the volatilities and melting points of known refractory and volatile nuclides. The assignments made here are generally consistent with designations made in other studies of transport from underground nuclear tests (IAEA, 1998;.…”

Section: Volume/surface Mode Designationmentioning

confidence: 99%

Modeling to Support Groundwater Contaminant Boundaries for the Shoal Underground Nuclear Test

Pohlmann¹,

Pohll²,

Chapman³

et al. 2004

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EXECUTIVE SUMMARYGroundwater flow and radionuclide transport at the Shoal underground nuclear test are characterized using three-dimensional numerical models, based on site-specific hydrologic data. The objective of this modeling is to provide the flow and transport models needed to develop a contaminant boundary defining the extent of radionuclide-contaminated groundwater at the site throughout 1,000 years at a prescribed level of confidence. This boundary will then be used to manage the Project Shoal Area (PSA) for the protection of the public and the environment.The PSA is located in north-central Nevada along the crest of the Sand Springs Range. The Shoal nuclear test was detonated on October 26, 1963. It had a yield of 12 kilotons and was located at a depth of 367 m below land surface. The Sand Springs Range is comprised of fractured granite and is bounded on the east and west by alluvium-filled valleys. Faulting is present in the range, with a prominent shear zone and other major faults striking southwest to northeast across the site. Groundwater recharge occurs by infiltration of precipitation on the mountain range, with regional discharge occurring in the valleys. A groundwater divide occurs below the upland area of the range, separating flow to the east and west. The nuclear test is located on the eastern side of the divide such that groundwater from the nuclear test area moves toward Fairview Valley.Geologic and hydrologic data to support the modeling were gathered during three different periods. First, regional hydrogeologic investigations and detailed site geology studies were conducted in support of the nuclear test in the 1960s. Second, the U.S. Department of Energy (DOE) drilled and tested four hydrologic characterization wells in 1996 that provide site-specific hydraulic parameters. After the 1996 data collection, an interim groundwater model was developed by . It was the basis for a Data Decision Analysis (Pohll et al., 1999b) that evaluated model uncertainties and identified optimum methods of reducing uncertainty. As a result of the recommendations of the DDA, the third data collection period occurred in 1999 to 2000, when DOE drilled and tested another four wells at the site, and conducted a tracer test between two of the wells.Data from these studies support a fundamental conceptual model for groundwater flow at the PSA of groundwater flow through the fractured granite, toward the adjoining valleys. Recharge is uniformly distributed across the surface of the Sand Springs Range, originating as precipitation. A hydrologic divide coincides with the upland areas of the range, forming a no-flow boundary west of the nuclear test. A region of higher conductivity and higher porosity is located around the cavity and chimney as a result of the nuclear test. A significant refinement to the conceptual model as a result of the 1999 field work is the recognition of a low-conductivity shear zone creating an impermeable no-flow boundary east of the nuclear test, dipping to the west.Alternate conceptual mode...

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Section: Volume/surface Mode Designationmentioning

confidence: 99%

Modeling to Support Groundwater Contaminant Boundaries for the Shoal Underground Nuclear Test

Pohlmann¹,

Pohll²,

Chapman³

et al. 2004

View full text Add to dashboard Cite

show abstract

“…For those nuclides with no specific literature reference, volatilities of oxides (Bedford and Jackson, 1965;Krikorian, 1981) and melting point temperatures are used to assign a behavior consistent with the volatilities and melting points of known refractory and volatile nuclides.…”

Section: Volume/surface Mode Designationmentioning

confidence: 99%

Modeling Groundwater Flow and Transport of Radionuclides at Amchitka Island's Underground Nuclear Tests: Milrow, Long Shot, and Cannikin

Hassan¹,

Pohlmann²,

Chapman³

2002

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EXECUTIVE SUMMARYThe groundwater flow and radionuclide transport at the Amchitka Island underground nuclear tests are modeled using two-dimensional numerical simulations. A multi-parameter uncertainty analysis is adapted and used to address the effects of the uncertainties associated with the definition of the modeled processes and the values of the parameters governing these processes. The nuclear tests performed at Milrow, Long Shot and Cannikin are the focus of this investigation. These tests were detonated on October 2, 1969, October 29, 1965, and November 6, 1971, respectively. The announced yield of these test are approximately one megaton for Milrow, 80 kilotons for Long Shot and less than five megatons for Cannikin.The flow model is conceptualized to address the problem of density-driven flow where the saltwater intrusion problem is encountered. The multi-parameter uncertainty analysis addresses the effects of the uncertainty associated with four of the parameters governing these processes on the resulting solution. These parameters are the hydraulic conductivity, recharge, fracture porosity and macrodispersivity. The heat-driven flow and three-dimensional flow features are addressed in a less rigorous manner via a sensitivity analysis. This includes the geothermal heat, the shot-induced heat effects, the chimney geometry, the effects of nearby faults and the effect of the island half-width. All the simulations presented in this report, as well as the sensitivity analyses, are performed using the FEFLOW model of the WASY Institute for Water Resources Planning and Systems Research Ltd.The conceptual transport model simulates many processes in addition to the advection-dispersion process. The release mechanism and glass dissolution, sorption effects, matrix diffusion and radioactive decay are among the processes modeled. The parametric uncertainty analysis also extends to three of the transport parameters governing the glass dissolution process, the matrix diffusion process and local scale dispersion. The solution of the transport problem is performed using a numerical particle-tracking algorithm and a semi-analytical solution is used for the matrix diffusion studies.Hydraulic conductivity data collected from six boreholes are analyzed to yield a best estimate for the homogeneous conductivity value and the range of uncertainty associated with this estimate. Temperature logs measured in several of the boreholes on the island are used to estimate groundwater recharge. Measurements of total porosity were made on numerous core samples obtained from four boreholes. There are no measurements for fracture porosity, and therefore, values for this parameter are selected based on reported values from the literature.Batch sorption experiments were performed using cores collected from the Cannikin emplacement well. Sorption on both basalt and breccia was investigated for strontium, cesium, and lead dissolved in water of basically seawater composition. The high ionic strength of the solution and rock properties resulte...

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“…For those nuclides with no specific literature reference, volatilities of oxides (Bedford and Jackson, 1965;Krikorian, 1981) and melting point temperatures were used to assign a behavior consistent with the volatilities and melting points of known refractory and volatile nuclides.…”

Section: Volumdsurface Mode Designationmentioning

confidence: 99%

Evaluation of groundwater flow and transport at the Shoal underground nuclear test: An interim report

Pohll¹,

Chapman²,

Hassan³

et al. 1998

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Volatilities of the Fission Product and Uranium Oxides

Cited by 17 publications

References 0 publications

Modeling to Support Groundwater Contaminant Boundaries for the Shoal Underground Nuclear Test

Modeling to Support Groundwater Contaminant Boundaries for the Shoal Underground Nuclear Test

Modeling Groundwater Flow and Transport of Radionuclides at Amchitka Island's Underground Nuclear Tests: Milrow, Long Shot, and Cannikin

Evaluation of groundwater flow and transport at the Shoal underground nuclear test: An interim report

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