Study of 137Cs deposits and migration in soils on several regions of Uzbekistan using γ-Spectrometry methods

This work is devoted to study the 137Cs deposits and migration in soils of several regions of Uzbekistan using γ-spectrometry methods. In order to determine 137Cs in soils samples we used the γ-spectrometry methods. The study shows that the sensibility of NaI(Tl) detector is higher than in case of Ge(Li) detector with V=100 cm3. The study investigated for first time in Uzbekistan the concentration of 137Cs on 20 samples taken from soils. It was shown that the levels of global and regional fall outs of 137Cs in the studied area (Q0=4.6-29.4 kBk/m2) is higher than in western zones of the same latitude of Earth. These differences grow even bigger in case of comparison of the data in regard to northern latitudes. The strengths of radiation doses of 137Cs were evaluated for studied areas: R=1-5 μSv/year. There is the correlation between the deposits of 137Cs and region altitudes above the sea levels. The dependence of migration processes of 137Cs on the type of the area and dependence of rate of vertical migration of 137Cs on the degree of the moisture in them were shown. The experimental data on the distribution of 137Cs were compared to the results of three model descriptions of vertical migration processes in the soil