Assessment of concentration limit for the safe disposal of very low leve wastes

Abstract

The large amounts of radionuclides are generated from the decommissioning of nuclear facilities (included the nuclear power plant). Because of this, countries or agencies using the nuclear power are one of considering issues for the effective disposal. Among decommissioning wastes, wastes have no or very limited radioactivity are disposed of in conventional landfill or recycled thought approval from regulatory control. And wastes like LILW (Low and Intermediate Level Wastes) or HLW (High Level Wastes) are sent the repository or the interim storage facilities. In order to solve the space problem of the LILW repository and reduce disposal costs, some LLW which are relatively lower than other LLW are classified as VLLW (Very Low Level Wastes). IAEA is added to the VLLW category of the radioactive waste classification and some countries are operating a VLLW disposal facility or will be operating. In this study, the VLLW acceptance criteria of each radionuclide are derived by considering the inadvertent human intrusion scenario applying to a study on the near-surface disposal (LILW). The effect of important parameter, especially, waste isolation period, dilution factor and food consumption rate, is considered. It is concluded that the concentration limits of radionuclides considering in this study are evaluated approximately between 1 and 100 Bq/g. These values are similar to the case of France and Spain and the IAEA’s predicted values. Based on this study, acceptance criteria of VLLW disposal facilities are suggested. And this study is contributed to the public relations for the safety of the VLLW disposal facility.