Methods for Calculating a Simplified Hydrologic Source Term for Frenchman Flat Sensitivity Studies of Radionuclide Transport Away from Underground Nuclear Tests

Abstract

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Modeling of Groundwater Flow and Radionuclide Transport at the Climax Mine sub-CAU, Nevada Test Site

“…The radiologic source term is typically separated into two fractions: the exchange volume and the nuclear melt glass volume (Tompson et al, 1999(Tompson et al, , 2004(Tompson et al, , 2005Pawloski et al, 2001;SNJV, 2004SNJV, , 2005a. Spatially, the exchange volume is typically visualized as a spherical volume centered about the working point.…”

Phase II Transport Model of Corrective Action Unit 98: Frenchman Flat, Nevada Test Site, Nye County, Nevada, Revision 1

“…The R c , shown in Figure 9-1, is calculated from the maximum announced yield, the bulk overburden density (2.1 g/cm 3 ), and the depth of burial (Pawloski, 1999;Tompson et al, 2004) as follows:…”

Unclassified Sources Term and Radionuclide Data for Corrective Action Unit 97: Yucca Flat/Climax Mine, Nevada Test Site, Nevada, Revision 2

“…• Methods for Calculating Frenchman Flat Source Term Sensitivity (Tompson et al, 2004). Provides an approach for the development of simplified unclassified HSTs.…”

“…According to Equation 3-1, the cavity radius is calculated from the maximum announced yield, the bulk overburden density, and the DOB (Pawloski, 1999). The overburden density used for this calculation (2.1 g/cm 3 ) is consistent with Tompson et al (2004). A representative yield for the shallow case was determined by examining all vadose zone tests with working points between 100 and 250 m bls in the AA HSU.…”

“…Efficient analytical models should be used to represent the important processes when possible. Analytical solutions are available for heat transfer in porous media for simple geometries (Nield and Bejan, 2006), or analytical expressions may be developed for the unique conditions occurring within the test altered zones in a manner similar to Tompson et al (2004). For example, a simple exponential function may be fitted to a decaying velocity field resulting from the test-induced pressure, and an analytical expression for a transient radionuclide flux may be obtained for simplified geometries.…”