Radiological impact assessment of a hypothetical accident at the Zaporizhzhia nuclear power plant

• Simulated dispersion of radionuclides from a hypothetical Zaporizhzhia NPP accident. • Assessed radiation dose using atmospheric dispersion and dose assessment models. • Radioactive plumes spread across the Northern Hemisphere within three weeks. • Effective doses were >1 mSv near Zaporizhzhia but remained <0.1 mSv elsewhere. • Emergency preparedness system in Korea is currently in real-time operation. The atmospheric dispersion of radioactive materials and the resulting radiation dose were assessed for a hypothetical accident at the Zaporizhzhia Nuclear Power Plant in Ukraine. The release quantities of 131 I and 137 Cs were assumed to be the same as those released into the atmosphere in the Chernobyl nuclear accident. The evaluation utilized atmospheric dispersion and dose assessment models, both of which are key components of the Radiological Accident Preparedness System in Korea (RAPS-K) developed by the Korea Atomic Energy Research Institute. Simulation results showed that radioactive plumes initially moved to the western across Europe, and later, some plumes were transported to the Asia due to westerly winds. Dose assessments revealed that effective radiation doses were showed above 1 mSv in certain areas near the Zaporizhzhia plant, while radiation exposure remained below 0.1 mSv across the rest of Europe, Asia, and North America. Especially, the thyroid dose due to 131 I was presented about 19 mSv and 29 mSv, respectively in Kyiv and Odesa of Ukraine.