Control over the processes of the nuclear fuel redistribution and fission products in the 'Ukrytie' under influence of the natural physical and chemical factors

To control over the processes of the nuclear fuel redistribution through the water flows inside the 'Ukrytie' method of tracers (indicator method) has been developed and applied. As a tracer sodium bromide has been chosen which was introduced inside through the regular system of dust suppressing. It has been found that as a result of fuel matrix destruction soluble and colloid forms of radionuclides and fission elements migrate with water flows to the lower elevations of the Unit and concentrate in the bottom sediments. Experimental research have demonstrated that as a result of radioactive aerosols transportation by air flows from the surface of the inside 'collapses' over the last 7 - 8 years redistribution of about 16 kCi of Cs137 and Sr90 radionuclides has taken place that comes to 20 % of surface activity