O. M. Zhukovaa, N. M. Shiryaevab, N. K. Myshkinab, V. V. Denisovab, and V. V. Skuratb UDC 504.453.054 Based on the multichamber model, prediction evaluations of the transfer of 137Cs and 90Sr in the Iput river for 100 years after the Chernobyl accident have been performed. In the course of investigation, the indicated time range was subdivided into three periods: the first period covered April-December of 1986 (retrospective evaluation), the second period embraced the years 1987-2000, and the third period covered the years 2000-2080 (long-term prediction). The prediction evaluations of migration of radioactive contaminants in the Iput river have shown that over the course of a century the concentrations of 137Cs in the Iput river network will decrease nearly 3000 times and the concentrations of 90Sr will decrease 10,000 times. However the levels of contamination of the river systems by these radionuclides will remain rather high. aRepublic Center of Radiation Control and Monitoring of the Natural Environment, State Committee for Hydrometeorology of the Republic of Belarus, Minsk, Belarus; email:; bInstitute of Radioenvironmental Problems, National Academy of Sciences of Belarus, Minsk, Belarus; email: Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 75, No. 1, pp. 191-199, January-February, 2002. Original article submitted January 16, 2001. JEPTER74920200217 JEPTER7492017