Population Dose Loads in Primorskii Krai from the Nuclear Accident on a Submarine in Bukhta Chazhma

The population dose loads from the radioactive cloud and at residential sites in the contaminated area weredetermined. The dose was determined according to 131–135I, 137Cs, 90Sr, and 60Co. The adjacent uninhabited Dunai Peninsula, Ussuriiskii Zaliv, Primorskii Krai, and China’s Heilongjiang boundary province were considered. The effective dose of external irradiation on Dunai Peninsula was the highest. It reached 80 μSv at a distance of 1.2 km from the source. The effect of radiation dose to the internal organs was equal to 440 μSv, of which the lungs received 250 μSv and the thyroid gland 20 μSv. The dose is a factor of 10 lower 5.5 km from the accident site on the coastline of the zaliv. In the coastal zone, where the population lives, the dose corresponded to 0.1–2 μSv and reached 3–6 μSv at individual sites. In Primor’e, it varied from 0.01 to 0.1 μSv and on Chinese territory it did not exceed 0.01 μSv. In permanent residential areas, the effective dose of internal irradiation was determined by 60Co. For the first year, it was equal to 0.1–6 μSv for adults in the coastal area of Ussuriiskii Zaliv, 0.001–0.1 μSv on the territory of Primor’e, and 0.0005– 0.002 μSv on Chinese territory. For children, it could be 10–20 times higher as a result of the consumption of locally produced milk. In comparison with the global average background yearly irradiation dose 2400 μSv and the admissible value 1000 μSv, the contribution of the consequences of a nuclear accident on a nuclear submarine in Bukhta Chazhma was equal to 1–2%. No additional radiation protection measures were needed for the population.