Radiological dose assessments according to dilution characteristics of radioactive materials in nuclear sites

This study quantified the characteristics of atmospheric dispersion and exposure dose of radioactive materials in four power plant sites in Korea. As a tool to quantify atmospheric dispersion, this study used air concentrations based on an assumed unit release of radioactivity per time. The disparities in atmospheric dispersion degrees among the sites were tested statistically with an analysis of variance (ANOVA). The probabilistic distribution of exposure dose in consideration of meteorological conditions in the case of a nuclear accident was estimated with a Monte Carlo simulation. The Yeoungkwang nuclear site on the west coast was the poorest in dispersion, whereas the most active dilution of radioactive materials took place in the Kori nuclear site located on the east coast on an annual basis. In case of an accident with the worst conditions of atmospheric dispersion, assuming the emission rate was 1 Bq/s and the duration time of the accident is 1 h, the highest 99.5th percentile of dose-1.51E−14 mSv.