Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAP8.0 REFERENCE AREAA surface soil reference area will be established and maintained for the duration of Phase 1activities. The reference area will be approximately 2,000 m 2 and will encompass surface soiltypes and conditions similar to those expected within the WVDP premises. The reference areawill have no historical evidence of contamination from NFS or WVDP activities, and there willbe no reason to believe such impacts might exist. Once established, the perimeter of the referencearea will be clearly demarcated, the interior brushed to allow easy access for sampling and grossactivity surveying, and the area protected from intrusion or disturbance for the duration of Phase1 activities. The reference area will be used to support both CSAP and FSS activities.8.1 Gross Activity Survey Reference Data CollectionOne purpose of the reference area is to assist in the development of gross activity survey data setsthat can be used for background purposes and to evaluate background performance of variousdetectors that may be deployed on the WVDP premises in support of gamma surveys.A 100-m 2 area within the reference area will be selected and further protected through the use ofa removable cover in a manner that maintains relatively stable soil moisture conditions for thisarea. The purpose of this cover is to allow reproducible results from gross gamma scans andensure comparability among gross activity scans of this area conducted by different detectors atdifferent times.Section 11.5 contains details about the data collection required for this 100-m 2 area.8.2 Background Soil Sample Reference Data CollectionThe reference area will be sampled once, at the initiation of CSAP activities. The purpose of thissampling and analysis will be (1) to establish a background data set that can be used for WRSstatistical tests as part of the FSS process, if that proves necessary, (2) to establish backgroundactivity concentrations and their distribution for radionuclides that are naturally occurring tosupport decision-making during CSAP data collection, and (3) to establish backgroundRev. 1 61