Risk-Based Radionuclide Derived Concentration Guideline Levels for an Industrial Worker Exposed to Concrete-Slab End States at the Savannah River Site.
Dose and risk assessments are an integral part of decommissioning activities. Most human health risk assessments are performed for a reasonable maximum exposure to an individual with assumed intake and exposure parameters that depend on the end state of the decommissioning activities and the likely future use of the site. Regardless of how the potentially exposed individual is defined, the subsequent calculated human health risk is not a measurable quantity. To demonstrate compliance with risk-based acceptance or cleanliness criteria, facility-specific risk assessments usually are performed after final-verification sampling and analysis. Alternatively, conservative, a priori, guideline concentrations for residual contaminants can be calculated and rapidly compared to the subsequently measured contaminant concentrations to demonstrate compliance. In response to the request for accelerated cleanup at U.S. Department of Energy facilities, the Savannah River Site (SRS) is decommissioning its excess facilities through removal of the facility structures leaving only the concrete-slab foundations in place. Site-specific, risk-based derived concentration guideline levels (DCGLs) for radionuclides have been determined for a future industrial worker potentially exposed to residual contamination on these concrete slabs. When appropriate, these conservative DCGLs will be used at SRS in lieu of facility-specific risk assessments to further accelerate the decommissioning process. This paper discusses and describes the methods and scenario-specific parameters used to estimate the risk-based DCGLs for the SRS decommissioning end state.