Concentration levels of technetium-99 in forest soils collected within the 30-km zone around the Chernobyl reactor

Technetium-99 (99Tc) concentrations in surface soil samples collected from three forest sites within the 30-km zone around the Chernobyl reactor were determined. A simple and rapid analytical method, which consists of volatilizing and trapping Tc in a combustion apparatus, purifying the Tc with an extraction chromatographic resin and measuring it by ICP-MS, was used for the determination. The concentrations of 99Tc in the samples ranged from 1.1 to 14.1 Bq kg−1 on an air-dried soil basis. The activities of the nuclide in the soils around the Chernobyl reactor were one or two orders of magnitude higher than in other areas which were less affected by the accident. The activity ratios of 99Tc/137Cs ratios in the soils were calculated as on the order of 3.7×10−5 to 1.3×10−4.