Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAP7.0 REMEDIAL ACTION SURVEYSRemedial action surveys refer to collecting data to assist in guiding remedial activities. In thecontext of the Phase 1 soil excavation program, these surveys can include guiding the progress ofexcavation (e.g., determining how far laterally excavation should proceed to addresscontamination), supporting the segregation of soils for waste disposition, and determining whencleanup objectives have been achieved so that the exposed excavation floors and walls are readyfor Phase 1 FSS data collection. Additionally, remedial action surveys may include documentingthe contamination status of exposed soil surfaces when Phase 1 activities are complete for thoseareas where Phase 1 FSS protocols will not be applied to demonstrate closure. An example of thisis hardstand removal in areas where contamination is known to exist at depths greater than 1 m,precluding the application of the Phase 1 FSS process for surface soils.This section of the CSAP discusses remedial action surveys to guide excavation, to determinewhen cleanup objectives have been achieved, and to document the contamination status ofexposed soil surfaces after Phase 1 activities are complete for those areas that will not be includedin the Phase 1 FSS. All soils excavated as part of Phase 1 activities will be sent off-site fordisposition following the requirements of the DOE radioactive waste management program. Therequired data collection and decision-making processes for waste disposition are a function of thefacilities available to receive the various waste streams that Phase 1 activities will generate andare a function of their waste acceptance criteria and documentation requirements. Data collectionduring remediation for waste disposition purposes is outside the scope of the Phase 1 DP andCSAP; data collection to support waste disposition will not be addressed as part of this plan, butmay be addressed in a Waste Management Plan developed to support the Phase 1 remediation.The historical soil sample data indicate that Cs-137 and Sr-90 will likely be the primarycontaminants of concern from a CG w perspective in soils to be addressed by Phase 1 activities.On the basis of the historical data, there are areas of the WVDP premises where these twocontaminants exist relatively independently of each other, and there are other areas where theyare commingled. Elevated (above levels that would occur in background soils) Cs-137 activityconcentrations in soils are readily identifiable by a variety of NaI-based gross gamma detectorswhen those activity concentrations are at CG w activity concentrations; consequently, Cs-137 canbe at least partially addressed by gross gamma activity scans as part of a remedial action survey.Rev. 1 53