Impact of Concrete Degradation on the Long-Term Safety of a Near-Surface Radioactive Waste Disposal Facility in Korea

The migration of radionuclides from radioactive waste into the environment poses a public safety concern. Thus, long-term assessment for near-surface disposal sites in South Korea entails providing reasonable assurance that annual radiation dose exposure radionuclide release repository biosphere will not exceed regulatory limit 0.1 mSv/yr. At first site Gyeongju, concrete was crucial component engineered barriers designed to contain within site. ability retain is attributed its high sorption capacity radionuclides. However, research has shown degradation can affect retention capabilities, which are defined by properties distribution (Kd) and diffusion (Ds) coefficient parameters. As result, changes may lead migrating out vault. In light geochemical deterioration barriers, this study assesses sites. To simulate impact on migration, we employed RESRAD-OFFSITE’s extended source-term features, model shielded barriers. Using carefully screened published data four (14C, 137Cs, 90Sr 99Tc) different stages degradation, results indicated released radioactivity during most degraded state result maximum 1.4 × 10−8 mSv/yr 99Tc below permissible mSv per year, thus demonstrating reliable facilities.