Protocol for development of authorized release limits for concrete at U.S.Department of Energy sites

摘要

The purpose of this protocol is to assist US Department of Energy (DOE) sites inreleasing concrete for reuse. Current regulations allow the sites to release surface-contaminated materials if their radioactivity falls below certain levels and to possibly release materials with volumetric contamination or higher levels of surface contamination on a case-by-case basis. In all cases, an ALARA (as low as reasonably achievable) analysis that evaluates the risks of releasing volumetrically contaminated concrete or concrete with higher levels of surface contamination is required as a basis for proposing and setting new release limits that allow for reuse of the concrete material. To evaluate the dose impacts of reusing radioactively contaminated material, the measured radiation levels (pCi/g or disintegrations per minute (dpm)/100 cm(sup 2)) must be converted to the estimated dose (mrem/yr) that would be received by affected individuals. The dose depends on the amounts and types of isotopes present and the time, distance, and method of exposure (e.g., inhalation or external exposure). For each disposition alternative, the protocol provides a systematic method to evaluate the impact of the dose on the affected individuals. The cost impacts of reusing concrete also need to be evaluated. They too depend on the disposition alternative and the extent and type of contamination. The protocol provides a method to perform a detailed analysis of these factors and evaluate the dose and cost impacts for various disposition alternatives. Once the dose and cost impacts of the various alternatives have been estimated, the protocol outlines the steps required to propose new release standards that allow release and reuse of the concrete material.