Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAPIn 1987, water from a 55-gallon drum containing spent resin leaked, spilling water on the ground.The drum was being transferred from the New/Old Hardstand to a waste solidification area in theProcess Building (WMA 1) when leakage was noted. Less than 15 gallons was spilled. Thewetted soil was measured at less than 100 dpm/g gross beta. A small amount of contaminated soilwas removed (DOE 2009 Table 2-18; DOE 2010 Section 3.11.5).E.5 Existing DataExisting data sets for this area include:• In 1982, static direct exposure readings were collected across the WVDP premises(WVNSCO 1982). All of WMA 5 was covered by these measurements on a 10-m grid.Figure E.10 shows these results color-coded by the exposure readings encountered, withthe data overlain on a 1977 aerial photograph. Interpretation of these data in the vicinityof the Process Building is complicated by possible shine impacts. These data indicate thepotential for significant surface contamination extending north from the WMA 3boundary. Although the color-coding used for Figure E.10 does not show it, the footprintof the Old Hardstand had direct gamma readings as much as ten times higher than thesurrounding soils. In general, direct gamma readings decreased with distance from theProcess Building. Table E.1 summarizes the availability of historical analytical data forsoils for each of the eighteen ROI.• In 1990 and 1991, a second static direct exposure measurement program was conductedacross the WVDP premises (WVNSCO 1992). In the case of WMA 5, this effortprovided systematic coverage for most of the WMA 5 area on a 10-m grid with theexception of the Old Hardstand and its immediate surroundings (likely due toconstruction activities at the time). This data collection used different instrumentation andprotocols than the 1982 study, so the results are not quantitatively comparable. Also,interpretation of these data in the vicinity of the Lag storage buildings may be affected bypossible shine impacts. Figure E.11 shows these results overlain on a 1984 aerialphotograph. Unlike other areas of the site, the 1990/91 survey for WMA 5 encounteredvalues significantly higher than those originally encountered in 1982, particularly alongthe northern boundary of WMA 5. In addition, the spatial pattern of surface direct readingRev. 1 E-8