Kinetics of the leaching of Sr-90 from fuel particles in soil in the near zone of the Chernobyl nuclear power plant

A method is presented for calculating the fraction of Sr-90 included in fue l particles ill soil. Data concerning the change in forms of the occurrence of Sr-90 in different soils in the 30-km zone, at different distances from the Chernobyl nuclear power plant, were used to obtain the kinetic charact eristics of its leaching: the first-order rate constant and the normalized rare 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 rare of solution of the fuel matrix v aries from 1.10(-5) to 6.1.10(-4). If was not found possible to clearly ide ntify the influence of the distance from the nuclear power plant on the lea ching rate in the northern and western sectors. In contrast, in the souther ly and south-easterly directions a clear tendency was observed for the leac hing rate to increase with increasing distance from the nuclear power plant .