Radioactive Contamination of the Central Russian Upland and Its Surroundings 21 Years after the Chernobyl NPP Accident

E. V. Kvasnikova, S. K. Gordeev, O. M. Zhukova, S. S. Kirov, S. V. Konstantinov, A. V. Lysak, and D. A. Manzon

The Chernobyl NPP accident resulted, due to the western atmospheric transfer, in the formation of a pattern crossing the Central Russian Upland and its surroundings in the latitudinal direction. A volatile long-lived dose-forming radionuclide 137Cs prevailed in the fallout. A peculiar character of the Central Russian Upland division by valleys and balkas could result in a 20-year period in radioactivity displacement down the slop to valleys. This article is devoted to checking the significance of such changes. The issue on revealing the differences between the measured contamination density values 21 years after the depositions and the expected values (calculated with the correction for 137Cs decay) is also under consideration.