Plutonium Content in Soil Fractions of Various Sizes and Estimation of the Risks of the Chernobil Nuclear Power Plant Zone.

Based on the data from the literature the authors analyzed the methods used for the estimation of the risks of plutonium-contaminated areas. The analysis was based on the published data on the measured plutonium concentrations in the air and soil. To calculate plutonium concentrations in the near-surface air layer above the contaminated area a modification of the method of the load estimation from the mass was proposed: instead of the average plutonium specific activity in soil the authors suggested the use of the soil coefficient which consists of the sum of specific activities of every respirable fraction (size 0.05 to 10 μm) multiplied by the percentage of its activity in the total activity of the soil sample. Verification of the proposed method on independent data showed that the calculated values approached the measured ones.