Radiological Assessment of Loss of Coolant Accident from Saeul Nuclear Power Plant

Background: South Korea’s extensive nuclear energy capabilities, driven by 25 operational nuclear power plants (NPPs), have been instrumental in supporting industrial development. However, concerns among antinuclear activists regarding the potential risks associated with nuclear accidents have emerged. To address these concerns, this study evaluated the long-term radiological effects of a nuclear accident on individuals living near an NPP site. In particular, this study focused on the most likely type of accident, a loss of coolant accident (LOCA), assuming that it occurs in a single unit because of the rarity of simultaneous accidents across multiple units.Materials and Methods: The source terms from the LOCA comprising 131I, 134Cs, 137Cs, and 90Sr were computed using the Radiological Assessment System for Consequence AnaLysis code, and these were fed into the GENII code, which computed the annual individual effective doses and cancer incidences at various distances and directions from the NPP.Results and Discussion: The effective dose contributions from food ingestion, ground exposure, and soil particle ingestion were 86.4%, 13.5%, and 0.01%, respectively, in children and adults. Food, particularly vegetables and meat, had the greatest impact on effective doses. Regarding individuals exposed at distances of 3, 16, and 30 km from the NPP, adults received annual effective doses of 98, 19, and 12 mSv, respectively, whereas children received doses of 56, 10, and 6.6 mSv, respectively. Comparison of the computed cancer incidence with South Korea’s past 8-year data resulted in a radiation exposure contribution to cancer of 0.012%, which was significantly below the NPP safety goal of 0.1%.Conclusion: This study suggests that radiation exposure from nuclear accidents has minimal impact on cancer incidence. Therefore, restrictions on vegetable and meat consumption should be implemented after accidents to mitigate the long-term health effects of radiation exposure.