The content of plutonium isotopes in the environmental objects of the Polesie State Radioecological Reserve

The study was carried out in the territory of the Polesie State Radioecological Reserve. For the study of long-term environmental effects of the Chernobyl accident in the territory of Belarus, the Polesie State Radioecological Reserve was established in 1988. It is located in the Belarus sector of the Chernobyl exclusion zone. The objective of the study was to estimate the content of plutonium isotopes in the environmental samples inside and outside of the Reserve area. Determination of plutonium isotopes was carried out by alpha spectrometry. The method includes complete decomposition of samples, radiochemical purification, preparation of alpha sources, alpha spectrometric analysis. The content of Pu-239+240 and Pu-238 in soil samples is in the range of 1.8-141 and <0.82-55 Bq/kg, respectively. The concentration of Pu-239+240 was at the level of n·10Е+0 Bq/kg in areas of the Kozeluga branch of the Khoiniki forestry, located outside the Reserve. Plutonium isotopes concentration outside the Reserve was an order of magnitude higher than it was in global fallout. The concentration of Pu-239+240 in pine cones in the study areas was <0.001-0.0041 Bq/kg. The Pu-239+240 transfer factor in Scots pine cones grown in the Reserve territory was at the level of n·10-4. The obtained value of the plutonium transfer factors for pine cones was comparable with the plutonium transfer factor for pine needles grown in the Reserve territory.