The estimation of radioactive isotopes accumulation in fish organisms of Lake Druksiai

It was being exploratored radiation pollution of fish living in water-cooling basin of Ignalina Nuclear Power Plant (NPP) in master's work. The objectives of work. NPP water-cooling basin's fish. The purpose of work was to estimate fish (Rutilus rutilus ( L.), Abramis brama ( L.), Esox lucius ( L.) and Perca fluviatilis ( L.)) contamination degree with macrobiotic radioisotopes cesium ( 137Cs) and strontium ( 90Sr) of Ignalina Nuclear Power Plant ( NPP) water cooling basin, to point up estimated radio-pollution concentrations dependence from fish capturing period of year, their (fish) varietal particularity, nutritional mode of fish life and compare with fish contamination by macrobiotic radioisotopes in other Lithuanian waters. Methods of work. Gama spectral analysis to estimate 137Cs levels in foodstaffs; 90Sr method estimation in foodstaffs and environmental samples by method of Tcherenkov radiation. The experiment was accomplished in the Laboratory of Environmental Protection – the subdivision of Ignalina NPP in 2004-2005. Samples of fish were delivered for the investigations by three times a year ( by 20 kg for every time (month); by 5 kg of different kind; totally 60 kg). It was being applied that method for statistical evaluation of secured data - calculable marks evaluation of secured results. All findings are on 95 % reliability level. The results of investigations showed, that larger specific activity of ( 137Cs) has been found in Esox lucius ( L.) and Perca fluviatilis ( L.) organisms than Rutilus rutilus (L.) and Abramis brama (L.). That is proving the intensity of 137Cs accumulation processes depends of fish varietal particularity and nutritional mode – trophic levels effect is typical for accumulation 137Cs. Levels of 137Cs not exceeded the safe quotas by EU Council Regulation ( EEC) No 737/90 ( 600 Bq/kg.). Specific activity of ( 90Sr) is very low and many times lower than by natural genesis radionuclide kalium ( 40K). That fact sustains a theory, that we can use fish for nourishment without limitation. The results of investigations showed, that fish contamination degree in the Lake Druksiai is very small and not exceeded the safe quotas. The fish contamination level of NPP water-cooling basin no differing from other water ponds and is resemble each other.Žemės ūkio akademijaVytauto Didžiojo universiteta