USE OF RECLAMATION TECHNOLOGIES TO REDUCE THE INTAKE OF RADIONUCLIDES INTO PLANTS ON CONTAMINATED AGRICULTURAL LANDS

The paper includes an assessment of the scope of agricultural land pollution with radionuclides caused by the Chernobyl accident, the classification of land by the degree of contamination with radionuclides Cesium (Cs) -137 and Strontium (Sr) -90. The paper describes the most common technologies for reducing the level of radionuclide intake by agricultural produce and provides the introduction rates for lime and mineral fertilizers on contaminated fields in the Bryansk region. The authors consider the descending -order sequence of grain crop according to their Cs-137 transfer coefficients. The paper also presents the assessment results of the contamination state of land in the Bryansk region 25 years after the accident. The problems of secondary local soil pollution caused by wind and water erosion are analyzed. A number of new technical solutions aimed at binding Cs-137 to the absorbing material, withdrawing it beyond the limits of the root layer (topsoil), as well as methods of extracting it from the soil, are also described in the paper, in particular, sowing perennial grasses with subsequent delivery of hay to special storage facilities; claying of the contaminated topsoil with its subsequent movement to a location deeper than the main mass of absorbing plant roots. The authors give account of several sorbents used for the removal of Cs-137 radionuclides. The technology of transferring Cs-137 to the sorbent by evaporation and drip irrigation is described. In addition, a possibility of flushing Sr-90 beyond the topsoil layer with the subsequent formation of slightly soluble salt is considered. The offered technical solutions provide for the decreased content of radionuclides in farm produce and the elimination of the localized pockets of radionuclide accumulation.