ESTIMATION OF DISSOLUTION RATE OF CHERNOBYL FUEL-PARTICLES IN NATURAL-ENVIRONMENT

The fraction of fuel particles dissolved by 1995 was estimated from th e data on the forms of occurrence of Sr-90 in various soil-climatic zo nes. The rate of dissolution proved to be primarily influenced by phys icochemical characteristics of the particles themselves rather than by environmental conditions. Analytical relationships are derived for th e rate of dissolution of fuel particles from the western and other fal lout tracks as a function of the soil acidity. The assessment is made for the dynamics of leaching of radionuclides from the matrix of fuel particles for various soils typical of the Chernobyl alienation zone w ithin the acidity (pH) range from 4 to 6.