Determination of volume of radioactive waste in activated VVER-1200 reactor structures

Abstract

The results of calculation studies of the amount of solid high-level, intermediate-level, low-level, very lowlevel radioactive waste (HLW, ILW, LLW, VLLW, respectively) generated during neutron activation of structural materials adjacent to the core of the VVER-1200 reactor plant, depending on the time after the final stopping it. An assessment of the volumes of radioactive waste (RAW) of activation origin generated over 60 years of operation of a VVER-1200 type reactor was carried out on the basis of computational studies of the induced activity of structural and protective materials using reactor and Monte Carlo program codes (SERPENT 2, TVS-M, DYN3D , MCU-PD). Specific activities for each isotope, total specific activities and activities, masses and volumes of activated structural and protective reactor materials for various categories of radioactive waste were calculated after the specified period of operation of VVER-1200 and over time after the final shutdown of the reactor. The obtained dependences of changes in the masses and volumes of activated materials over time after the final shutdown of the reactor make it possible to determine these parameters of materials separately for each category of radioactive waste and in total at any point in time. Thus, the masses of activated materials related to radioactive waste will decrease by 264 tons (from 713 to 449 tons) over 200 years of aging, and the volumes will decrease by 74.3 m3 (from 169 to 94.7 m3). Forecast quantitative data on the volumes and mass of activated reactor structures, depending on the duration of their exposure after the final shutdown of the power unit, will make it possible to develop technical proposals, forecast plans and schedules for organizing a radioactive waste management system during the decommissioning of the VVER-1200 reactor plant, as well as possible technological and design solutions for the disposal system for these radioactive waste.