Assessment of the radiological situation resulted by the accidental release of fuel particles

Physical-and-chemical properties of Chernobyl hot particles (radionuclide and dispersal composition, nuclear fuel burn-up and radionuclides fractionation, composition of particle matrix etc.) including the fuel particles as specific form of Chernobyl radioactive fall-out were studied [!]• Attempt to reconstruct the conditions of the fuel particles (FP) formation during the accident was done [2,3]. Oxidisation of nuclear fuel was shown to be one of the main mechanisms of FP formation during the ChNPP accident [4]. Maps of the near zone of Chernobyl accident contamination with radionuclides contained in deposited fuel particles were built [5]. It was shown that previous assessments of 9 0 Sr and transuranic elements contents in soils of the 30-km zone has been 3-4-times overestimated. Dependencies of the fuel particles dissolution rate on level of FP matrix oxidation and acidity of a medium both for natural conditions, and model media were obtained [6,7]. Prognosis of the plants contamination dynamics along the fuel traces of radioactive fall-outs was done [6,8]. Problems of the secondary radionuclides transfer in natural conditions, due to technogenic action to soil [9] and forest fires [10], as well as a significance of the FP inhalation intake into human body [11,12] are considered. Parameters of metabolism of FP-associated radionuclides in agricultural animals organism were obtained [13].