Some data on transuranium element distribution in particle size fractions of Chernobyl soils

Some Chernobyl soils were collected in the north-west direction. The samples have been separated into particle size fractions 1-2; 0.5-1; 0.25-0.5; 0.16-0.25; 0.05-0.16; 0.01-0.05; 0.005-0.01; 0.002-0.005; 0.00005-0.002; and less than 0.00005 mm. The fractions were analyzed on 238,239,240Pu, 241Am, 242,244Cm content. In contrast to the global plutonium fallout, the peak of plutonium activity falls in the particle size range of 0.01-0.05 or 0.005-0.01 mm in Chernobyl soils. Transplutonium elements are more mobile in the soil. As the distance from Chernobyl increases, the trend of their distribution becomes much similar to the global fallout. It is found that the most mobile part of soil with particles of sizes less than 0.05 mm contains 55-70% of plutonium activity and 30-65% of americium and curium activity. (author) 7 refs.; 6 tabs