Meteorologinių veiksnių įtakos Lietuvos teritorijų taršos 137Cs ir 131l radionuklidais po AE avarijų tyrimas ; Evaluation of meteorological factors impact on lithuanian territory contamination by 131l and 137cs radionuclides after npp accidents

Nuclear energy is one of the most economical energy sources in our days. However, the disasters in nuclear power plants cause severe consequences. The aim of this work is to simulate effects of the Chernobyl and Fukushima NPP incidents in different meteorological conditions. The PC COSYMA 2.0 program code was used to verify hypothesis that the deposition of the radionuclides depends on meteorological conditions, especially rain. The PC COSYMA codes use the Gaussian model to calculate atmospheric dispersion on radioactive material. Dry and wet deposition have the greatest influence on the computing. After nuclear accidents Iodine-131 and Caesium-137 are the main radionuclides that determine contamination. Therefore the focus is based on Caesium-137 in this work. After Chernobyl NPP incident the major plume of fallout drifted in northwest way. One of conclusion is that major reason of cesium-137 contamination in Lithuania is dry deposition.