"Radiotoxicity" of some radionuclides of the spent nuclear fuel from WWER and Brest reactors in different storage time periods, evaluated with ICRP models

The paper presents results of analysis of lifetime attributable risk (LAR) of cancer as a result of radiation exposure due to intake of some radionuclides, components of the nuclear fuel irradiated in BREST and WWER reactors. For risk calculation models described in ICRP 103 publication and identified groups of people exposed to internal radiation, specified by radiation dose, age and sex were used. Different time periods of storage of the spent fuel from 10 to 107 years were used, as well. 5-year old girls will be the most vulnerable group of the exposed people, they will have the highest LAR value. Within storage period to 10000 years the primary radionuclides of the nuclear fuel irradiated in the BREST reactor, contributors to LAR, will be 137Cs and 90Sr (storage period - 10 y); 241Am, 137Cs, 238Pu and 90Sr (storage period - 100 y); 241Am, 239Pu and 240Pu (storage period - 1000 y); 239Pu and 240Pu (storage period - 10000 y). The primary radionuclides of the nuclear fuel irradiated in the WWER reactor, contributors to LAR within time period of 1000 y will be 241Am, 246Cm and 240Pu. The relative contribution of the radionuclides to LAR value will exceed 10%. The LAR value of the primary contributors from the fuel irradiated in the WWER reactor will be higher than LAR value of the primary contributors from the fuel irradiated in the BREST reactor. It means that “radiotoxicity” of the spent nuclear fuel from WWER is higher as compared with “radiotoxicity” of the used fuel from the BREST. The obtained data are very important for SNF management and implementation of transmutation fuel cycle.