Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAP6.2 Verify Absence of Additional ROIIn addition to the 18 ROIs contained in the Phase 1 DP, another 12 radionuclides have beenidentified as potentially being of interest; these 12 potential ROIs are listed in Table 3. Theidentification process relied on historical process knowledge; to date none of these 12 has beenobserved in historical samples at levels that would be of dose concern and the belief is that it isunlikely that any of these 12 exist at significant levels in environmental media. Several of the 12have short half-lives relative to the history of WVDP/Nuclear Fuel Services, Inc. (NFS) activities;others would have had very low abundance within the spent fuel that would have been processedat the site, compared to Cs-137 and Sr-90.CSAP data collection will provide supporting data to determine whether any of these 12radionuclides should be of interest. A subset of CSAP samples will be analyzed for theseadditional 12 radionuclides. This subset will focus on samples from WMAs and settings in whichthey would most likely be encountered, if environmental releases at detectable levels hadoccurred. The WMAs of primary interest include WMA 1, 2, 3, 5, 6, 7, and 9. Example settingsof particular interest include elevated areas identified by gross gamma scans that might beindicative of discrete releases, buried infrastructure where associated soil contamination is likelypresent, areas of known environmental releases, and so on.In the cases of WMA 1 and WMA 2, because of the relatively higher and more pervasivecontamination levels expected, in addition to the analysis of biased samples for the 12radionuclides listed in Table 3, 10% of all other soil samples will be analyzed for the completesuite of 30 radionuclides.When soil samples are collected, sufficient soil mass will be obtained to allow for an analysis ofall 30 radionuclides (i.e., the 18 ROIs plus the 12 potential ROIs). For any particular WMA, if ananalysis of a sample for the 12 potential ROIs identifies one or more present at levels that wouldbe considered potentially significant, the balance of the samples from that WMA will also beanalyzed for the radionuclide(s) identified as occurring at levels of potential significance.“Potentially significant” is defined to be a radionuclide that is detectable, exceeds the 95% UTL(upper tolerance level) value for background, and occurs when the SOR value for the sample(based on the 18 ROI) is less than one.Rev. 1 27