Artificial radionuclides in aquatic plants of the Yenisei River in the area affected by effluents of a Russian plutonium complex

The Yenisei River, one of the largest rivers in the world, is contaminated with artificial radionuclides released by one of the Russian nuclear plants, which produces weapons-grade plutonium and has been in operation for many years. The aim of the study that was conducted between 1997 and 2002 was to investigate accumulation of artificial radionuclides by aquatic plants of the Yenisei River. The aquatic plants sampled were: Potamogeton lucens (shining weed) and Fontinalis antipyretica (water moss). The gamma-spectrometric analysis of the samples of aquatic plants for artificial radionuclides has revealed a wide spectrum of long-lived and short-lived radionuclides. Artificial radionuclides such as Cr-51, Mn-54, Co-58, Co-60, Zn-65, Cs-137, and Eu-152 were found in aquatic plants collected both near the plutonium complex and 194 km downstream in the river. The radiochemical analysis of aquatic plants revealed strontium and isotopes of plutonium. Fontinalis antipyretica had very high concentration factors of the principal radionuclides: 14220, 3110 and 500 of Cr-51, Sc-46 and Np-239, respectively.