Procedures and findings of examination of air contamination by alpha-active plutonium aerosols: Primary and secondary products of Chernobyl accident

Abstract

Atmospheric contamination pattern by Pu-radionuclides over a 30 km zone of the Chernobyl nuclear power plant in 1987–1988 has been examined. Aerosol samples were analyzed for isotopic composition by using gamma- and alpha-spectrometric, and radiochemcal methods. Preliminary analysis of isotopic and fractional composition of aerosols carried out earlier indicated that over the first few months after the Chernobyl accident the relative contribution of^238,239,240Pu to air contamination was lowered as compared with beta-active products. At present, however, alpha-active plutonium isotopes became the dominant radioactive contaminants of the atmosphere and the concentrations of^238,239,240Pu inhaled fractions turned out to be lower than the limiting permissible values based on the USSR radiation safety standards for radioactive contamination of the atmosphere for the limited part of population exposed to radionuclides. Neverheless, it is necessary to know even moderate levels of atmospheric contamination by Pu-radionuclides, since their long impacts on the personnel operating in the 30 km zone of the Chernobyl NPP and population residing in the adjavent regions have not been studied properly. So, the risks for population health of such impacts cannot be generally excluded from consideration.