Physical properties and limitations of radionuclides atmospheric transport models for different space and time scales

It was considered approaches to the problem of adequate choice of radionuclide atmospheric transport model for an estimation and prognosis of environment radioactive contamination due to a large communal accident at NPP. The spatial and temporal scale of the task, source term parameters, physical and geographical features of district of NPP location are examined as basic criteria. The uncertainty intervals of calculation results are estimated for the Gaussian model, which are determined by the errors of measurements of the model input meteorological parameters. It was carried out the analysis of possible w errors of results due to improper use of Gaussian model outside its applicability area. Possible approaches for model modification are indicated for extending of its application domain and increasing of calculations exactness, which were realized (or are planned for a realization) in the computer system of prognosis of radiation situation KADO at Rivne NPP