Retrospective Estimation of Potential Mobility of Artificial Radionuclides (60Co, 137Сs, 152Eu, 154Eu) in Bottom Sediments of the Yenisei River

The present study addresses transformation of physicochemical forms (species) of artificial radionuclides in bottom sediments (BS) of the Yenisei River after the shutdown of the reactors at the Mining-and-Chemical Combine (MCC) at Krasnoyarsk. The BS samples collected from the Yenisei at the MCC in 2018–2021 contained 60Co, 137Cs, 152Eu, 154Eu, 155Eu, and 241Am. The species of radionuclides were studied using sequential extraction procedure. Considerable proportions of 60Co (48–100