Abstract
OBJECTIVE: To reconstruct the 131I activity concentrations in air and 131I ground deposition densities from 26 April to7 May 1986 from the radioactivity release after the Chornobyl accident in the settlements of Ukraine using themesoscale radionuclides atmospheric transport model LEDI and meteorological information from the numericalweather forecast model WRF and to compare the obtained results with those calculated previously as well as withavailable measurements of 131I activity in soil.Object of research: the near-ground layer of the atmosphere and the surface of the territory of Ukraine radioactively contaminated as a result of the Chornobyl accident.Materials and methods of research. The dispersion of 131I in the atmosphere and deposition on the ground surfacein Ukraine were calculated using the Lagrangian-Eulerian diffusion model LEDI. The detailed fields of meteorological parameters calculated using the mesoscale weather forecast model WRF, which was adapted for the territory ofUkraine, were used as input data for the LEDI model. RESULTS: The 131I daily-average activity concentrations in the surface air and 131I daily ground deposition densitiesfrom 26 April to 7 May 1986 were calculated using the up-to-date mesoscale model of numerical weather forecastWRF for 30,352 settlements in entire Ukraine, including 1,263 settlements in Kyiv, 1,717 - in Zhytomyr and 1,570 -in Chernihiv Oblasts. CONCLUSIONS: The method of mathematical modeling of the atmospheric transport of the radionuclides is combination with the up-to-date mesoscale model of numerical weather forecast WRF is a useful tool for reconstruction ofradioactive contamination of the air and the ground surface after the Chornobyl accident. Calculated in this study131I activity concentrations in air and 131I ground deposition densities were used to reconstruct the thyroid doses dueto 131I intake to the population of Ukraine.