Choosing the method of calculating the impurity scattering in the atmosphere with normalization of the radionuclide emission from high sources

The maintenance of environmental-quality standards in the operation of commercial and power installations releasing radionuclides into the atmosphere depends significantly on whether correct account is taken of the meteorological factors determining the propagation of impurities in the atmosphere. Systematic investigation of atmospheric diffusion accompanying the release of harmful chemical materials has led to the development of the two most widespread models of impurity scattering in the atmosphere: a model based on solving the semiempirical equation of turbulent diffusion and applying the results of studying moisture and heat transfer, and the Gaussian model which is constructed using statistical laws. The results of calculating the normalized annual mean concentration for all wind directions for the Chernobylskii atomic power plant (RBMK-1000 reactor, source height 150 m) by the Pasquill-Gifford and Leningrad Hydrometeorological Institute methods are shown. The theoretical normalized concentrations in the region of the maximum and beyond, to a distance of 5-10 km, differ by more than a factor of 10 for the same wind directions. The introduction of a GOST state standard on limiting permissible releases of material contaminating the atmosphere is solved using the principles of the specialist PDV-83 method developed by the State Commission on Hydrometeorology