CESIUM-137 AND SR-90 CONTAMINATION OF WATER BODIES IN THE AREAS AFFECTED BY RELEASES FROM THE CHERNOBYL-NUCLEAR-POWER-PLANT ACCIDENT - AN OVERVIEW

Results of observations the contamination of the Ukrainian, Byelorussi an and Russian Federation rivers, the Dnieper reservoir chain, the Dni eper reservoir chain, the Dnieper estuary and the Black, Baltic and Az ov Seas by cesium-137 and strontium-90 after the Chernobyl accident, c arried out in 1986-1991 by the Institutions of the USSR State Committe e for Hydrometeorology, are presented and discussed. The dynamics of c ontamination levels and radionuclide removal into the Kiev reservoir a re studied. It is shown that the primary sources (over 90%) of cesium- 137 and strontium-90 fluxes into the Kiev reservoir are the Pripyat an d Dnieper Rivers. The impact on the area closest to the Chernobyl plan t on the Pripyat River with regard to pollution by strontium-90 is ass essed via qualitative estimates. The dynamics of pollution of the Dnie per reservoir chain are considered. It is shown that the greatest part of the cesium-137 is absorbed by the reservoir bottom (about 95%), wh ereas strontium-90 passes right through the chain. Sea-water pollution dynamics are also studied and the inputs of cesium-137 and strontium- 90 into the Black, Baltic and Azov Seas as a result of the Chernobyl a ccident are estimated.