Estimation of radionuclides global fallout levels in the soils of CIS and eastern Europe territory

Influence of operation of thermal and fast reactors of the Beloyarsk NPP on the radioecological situation in river ecosystems

The results of long-term radioecological monitoring of seven rivers in the 15-km zone of influence of the Beloyarsk Nuclear Power Plant have been presented. A comparative analysis of the content of a wide range of natural and artificial radionuclides in the main components of river ecosystems: surface waters, bottom sediments, floodplain soils, macrophytes and ichthyofauna has been made. The influence of waste technological waters of thermal (AMB-100 and AMB-200) and fast (BN-600 and BN-800) reactors of the Beloyarsk NPP on the content of radiologically significant isotopes in the water and bottom sediments of the Pyshma and Olkhovka rivers has been evaluated. It has been studied that the transition from thermal to fast reactors contributed to a significant decrease in the intake of artificial radionuclides into the rivers of the area where the Beloyarsk NPP is located. So, in the water of the Olkhovka river for the period 1978-2019 the decrease in the specific activity of ¹³⁷Cs was 480, ³H - 36, ⁹⁰Sr - 3.5 times. The maximum discharge of artificial radioisotopes into river ecosystems was noted during the period of recovery work after emergencies at the AMB-100 and AMB-200 reactors. In recent years, the content of artificial radionuclides in water, macrophytes and ichthyofauna of rivers in the zone of influence of the Beloyarsk NPP, except for the Olkhovka, is at the level of the regional background.