137Cs distribution on the territory of Romania 30 years after Chernobyl accident

Abstract

To estimate the contribution of Chernobyl 137Cs contamination, in 1993 and especially 2016, its total inventory was determined by gamma-ray high-resolution spectroscopy in 62 and respectively 747 soil samples covering the entire Romanian territory. This permitted us to estimate the 1993 and 2016 total 137Cs inventory to 43 ± 2 TBq and respectively to 14.1± 0.7 Tbq, the last one reduced by a factor of 3 ± 0.3. This value, about twice higher than natural disintegration suggests a significant amount of 137Cs being washed out by precipitation and, in a lower measure, incorporated into plants. At the same time, by evaluating the maximum contribution of 137Cs to the population exposure, in 1993 and especially in 2016, the supplementary annual effective dose did not exceed, the maximum accepted value of 1 mSv.