[Assessment of modern radioecological situation at nuclear explosion "Chagan" (Balapan Site, Semipalatinsk Nuclear Test Site, Kazakhstan)].

Results on estimation of modern radioecological situation at nuclear explosion "Chagan" based on large-scale cartographic studies (1:25000) of a test area (4 km2) are presented. Maximum gamma-irradiation doses were observed at bulk of ground surrounded a crater and at radioactive fall-outs extended to the North-East and to the SouthWest from the crater. Based on data on artificial radionuclide specific activity most part of soil samples were attributed to radioactive wastes according to IAEA (1996) and OSPORB (1999). Natural decrease of soil radioactivity up to safety level due to 60Co, 137Cs, 90Sr, 152Eu, 154Eu radioactive decay and 241Am accumulation-decay will not take place within the next 60 years at the studied area.