Анализ результатов радиационно-экологического мониторинга в регионе размещения Курской АЭС

The research presents the data of long-term observations of the impact of the Kursk Nuclear Power Plant operation on the radioecological situation in the region of its location. The dynamics of the content of natural and artificial radionuclides in the components of agricultural ecosystems was studied due to the data based on the information from the radioecological monitoring network developed in 2003. Samples of soils, agricultural products and animal feeds were taken at 11 control sites located on arable lands and grasslands in the vicinity of the Kursk Nuclear Power Plant, and, in settlements, locally produced food was sampled. It was shown that for the period of studies of 2003-2019, the average specific activity of 90 Sr in the soils of agroecosystems of the 10 km influence zone of the Kursk Nuclear Power Plant varied within 2.7-4.3 Bq/kg, and specific activity of 137 Cs was 14.6-40.8 Bq/kg. At the same time, there were found no trends of increase in the content of artificial radionuclides in soil over time and at different distances from the NPP, and the increased specific activity of 137 Cs in soil compared to the global background is explained by the Chernobyl fallout. The variability of the average content of natural radionuclides in the soil for 40 K was 481-625 Bq/kg, 226 Ra – 20.6-29.5 Bq/ kg, 232 Th – 28.2-39.2 Bq/kg, which corresponded to all-Russian data. The average specific activity of 90 Sr in grain was 0.24-0.43 Bq/kg, and 137 Cs – 0.19-0.37 Bq/kg. Even the maximum levels of artificial radionuclides in grain were 44 times for 90 Sr and 85 times for 137 Cs lower than the current SanPiN standards. The highest specific activity values of 137 Cs and 90 Sr in potatoes, vegetables, and gourds were 160 times lower than the SanPiN standards. It was noted that the maximum content of 90 Sr in milk was more than 540 times lower than the SanPin standard, and for 137 Cs this difference was 330 times. The maximum content of 137 Cs in beef turned out to be over 850 times lower than the SanPiN standard for this radionuclide. About 70 Bq/a of 90 Sr and 200 Bq/a of 137 Cs enter the population diet with locally produced food, which is almost 400 times for 137 Cs and 200 times for 90 Sr lower than the annual limit. Milk (46%), meat (31%), potatoes and vegetables (14%) make the main contribution to the formation of the internal dose from agricultural products containing 137 Cs, and contribution to dose from 90 Sr is made by milk (14%) and crop products (potatoes, vegetables, bread) – up to 78%. In general, we concluded that over the past 17 years, the operation of the Kursk Nuclear Power Plant did not lead to a deterioration of the radioecological situation in the region of its location, because during the survey period there was no significant increase in the content of artificial radionuclides in agricultural products, foods and environmental components.