Water migration of Chernobyl radionuclides in rivers of Belarus

The State Committee for Hydrometeorology, The Republican Centre of Radiation and Environment Monitoring, 220023 Minsk, Belarus

Abstract

The analysis of formation of radioactive contamination of rivers of Belarus, entering the Dnieper basin (Dnieper, Sozh, Iput, Besed, Pripyat), after the accident at the ChNPP is given in the paper. The legitimacies and features of behaviour of Chernobyl radionuclides in surface waters are detected. The total runoff of ¹³⁷Cs by the main rivers Sozh (Gomel), Dnepr (Rechitsa), Pripyat (Mozyr), Iput (Dobrush), Besed (Svetilovitchi) for the period 1987-2000 is submitted. The peculiarities of carrying out the monitoring at the experimental watershed of the Iput' river (the Dnieper-Sozh basin), flowing through the Byelorussian-Bryansk "caesium" spot, are described. The conceptual and mathematical models of radionuclide migration in the river network is suggested. The calculations have been conducted and the analysis of the experimental and calculated data on transport of radioactive contamination have been carried out. The prognosises of distribution of radioactive contamination in the rivers of Belarus (for example the Iput river basin) are obtained. The reliability of forecasting results of radionuclide behaviour in the rivers is confirmed by the data received on the network of radiation monitoring.