STUDY OF CHERNOBYL HOT PARTICLES COMPOSIT ION AND DISTRIBUTION

Experimental approach to investigation of Chernobyl hot particles and some results are presented in our study. Hot particles (HP) pickes out from soil samples collected during 1986-1990 radiogeochemical expedit ions in contaminated zone (within 30 km from Nuclear Power Plant). A n umber of hot particles were studied to estimate their contribution in total activity, to investigate their surface morphology and determine size distribution. Hot particles contribution in total activity in the 30 km zone was found to be not below 65%, Investigation of HP element al (by neutron activation analysis and EPMA) and radionuclide (direct alpha- and gamma-spectrometry, including determination Pu and Am in HP ) composition revealed certain peculiarity of HP, collected in vicinit y of damaged Nuclear Power Plant. Some particles show to contain urani um and fission products in proportions, correlating with those in part ially burnt nuclear fuel, that proves their ''fuel'' origin. Other par t of HP samples has been revealed element fractionation as well as pre sence of some terrestrial components.