The content of 103Ru in components of fresh-water and adjoining to them ground ecosystems after accident on ChNPP

The content of 103Ru in components of various fresh-water reservoirs and coastal ecosystems of Ukraine was studied since 1986 till 1987. It is established, that the maximal content of 103Ru in water’s ecosystems was typical for the higher water’s plants. The maximum of the content of 103Ru in fishes is registered in cooling-pond of ChNPP. It is caused by the vast radionuclide pollution of cooling-pond during the active moment of accident. Probably, the main quantity of 103Ru penetrates into organism of fishes on the trophic way. With increase if distance from ChNPP the content of 103Ru in fishes decreases. Thus, the level of biological availability of 103Ru for fishes increase. It is obvious, that it is caused by the sizes of the particles which have fallen in researched reservoirs and/or the physical and chemical form of 103Ru finding of in the fallout.