Reconstruction and verification of volume specific activity of atmospheric and fallout 131I and 137Cs during deposition of radioactive products from the Chernobyl NPP

The article presents method for reconstruction of rayon average volume specific activities of atmospheric and fallout (in case of lack of meteorological data) 137Cs and 131I during deposition of radioactive products after the accident at the Chernobyl NPP. Deposition densities of 137Cs and 131I evaluated with the use of reconstructed specific and volume activities of the radionuclides coincide with actual values based on spectrometric data of soil samples. Such basic factors as volume specific activities of atmospheric and fallout 137Cs and 131I in atmosphere, deposition of radionuclides from fallout, density of pasture flora biomass jointly effect on spatial distribution of reconstructed specific densities of contamination of pasture flora with 137Cs and 131I at the beginning a cattle grazing in 4 Russian territories. Mutually agreed base of radioecological data was developed for further research into effects of basic factors on spatial structure of internal radiation doses to the thyroid and the body of the population resided in territories of Russia contaminated with radionuclides in 1986.