[The state of radioactive pollution in the Techa River]

The concentration of radionuclides in the upper river water depends on radionuclides flow from the Techa Cascade of Reservoirs (TCR) with filtration waters and water of bypass canals. Further concentration dynamics over the river depends on floodplain and bottom sediments contamination level. Perennial concentration dynamics of 90Sr and 137Cs in the Techa River water is stably decreases. At present time concentration of 90Sr in the water depends on TCR inflow mainly and concentration of 137Cs depends on the outflow from contaminated swampy floodplain of the upper rive. From the dam-11 to the river entry radionuclides content in the silt, as well as in the water is stably decreases. Specific activity of 137Cs in the silts is 5 rates higher than in the water and 90Sr - 3 rates higher. In the silts 137Cs prevails in the difficult of access forms, 90Sr prevails in the exchangeable and moveable forms. The highest contamination density of floodplain soils is registered in the Asanov and Muslyumov swamps area. With time content of 90Sr and 137Cs planes along the soil septh, so overall deposits are decreases. The floodplain soils contains 66.5% of 90Sr in water soluble and exchangeable forms and 94.3% of 137Cs in difficult of access forms.