Environmental impact assessment framework development for radioactive material release to ocean

Abstract

Radioactive material can be released through many ways from nuclear power plant, radioactive material processing facility, or other facility. Released radioactive material can be dispersed along with ocean current. Then, dispersed radioactive material can be accumulated in ocean biota through food chain and it can affect human health through seafood intake. In this study, a framework for released radioactive material to ocean induced environmental impact assessment was developed by applying ocean simulation model, particle dispersion model, and bioaccumulation model. Local environmental conditions of Korean ocean were reflected on framework development. Since the West and South seas of Korea are tidal dominant ocean, a tidal motion induced ocean simulation model, 2D ADCIRC, was utilized for this analysis. Along with ocean simulation model, Cs-137 and Sr-90 were assumed to be released constantly and locations of radionuclide particles over time were simulated by Maureparticle model to calculate regional seawater activity concentration. Then, 12 species were selected as target biota for bioaccumulation model because they are highly consumed in Korea. Using their seasonal habitats and concentration factors, biota activity concentrations were estimated and probability distributions of effective doses were also constructed applying dose conversion factor and sampling method. From an analysis that developed framework is applied to, effective doses of all analyses were lower than annual dose limitation (1mSv) with high probability. Although the optimum models and reference data were applied for developed framework, there are several improvement points: concentration factors, the number of dispersed particles, mesh for ocean simulation model, local reference variables for food chain model, and spatial diversity of a zone. These aspects can be treated in further study.