INFLUENCE OF AGRICULTURAL COUNTERMEASURES ON THE RATIO OF DIFFERENT CHEMICAL FORMS OF RADIONUCLIDES IN SOIL AND SOIL SOLUTION

The bioavailability of radionuclides derived from the Chernobyl accide nt is discussed in terms of their speciation in soils. A scheme repres enting transformation processes of different chemical forms of these r adionuclides in soil and soil solution is proposed. The rate constants of the main transformation processes were obtained experimentally. Va rious agrochemical countermeasures are evaluated in terms of their inf luence on the ratio of different radionuclide forms in soil and soil s olution. The influence of soil characteristics on the potential effect iveness of countermeasures is discussed. Practically all agrochemical countermeasures currently in use have positive and negative effects. T he most effective countermeasures for radiocaesium and radiostrontium were liming of the soil and the application of potassium containing fe rtilisers at elevated rates.