Kinetics of the leaching of90Sr from fuel particles in soil in the near zone of the chernobyl nuclear power plant

A method is presented for calculating the fraction of90Sr included in fuel particles in soil. Data concerning the change in forms of the occurrence of90Sr in different soils in the 30-km zone, at different distances from the Chernobyl nuclear power plant, were used to obtain the kinetic characteristics of its leaching: the first-order rate constant and the normalized rate of solution. Depending on the direction and distance from the nuclear power plant, the first-order leaching rate constant varies from 3·10−5 to 2·10−3 days−1 and the normalized rate of solution of the fuel matrix varies from 1·10−5 to 6.1·10−4. It was not found possible to clearly identify the influence of the distance from the nuclear power plant on the leaching rate in the northern and western sectors. In contrast, in the southerly and south-easterly directions a clear tendency was observed for the leaching rate to increase with increasing distance from the nuclear power plant.