Estimation of Radioactive Waste for Decommissioning of KANUPP-1 Reactor

After 48 years of successful operation, the KANUPP power reactor is being planned to permanently shut down in 2020 for its decommissioning. The decommissioning plan requires the estimation of radioactive waste generated during the reactor operation life. There are number of structural materials used in different components of the KANUPP reactor and shielding. Outside the reactor core, the major components include concrete biological shield, core end shield assembly, dump tank etc. These components are being irradiated since first criticality of reactor. This paper highlights the activation calculations (radioactive waste estimation) of the primary concrete shield. For this purpose, a detailed 3D model of the KANUUP reactor shield is developed using Monte-Carlo MCBEND computer code to predict average core flux for activation calculations. The developed model is used to simulate the flux at various surfaces/regions of interest in vicinity of core. Applying the calculated flux and time of irradiation, neutron activation is estimated employing the depletion analysis computer code ORIGEN2. The radioactivity and masses of the irradiated radioactive elements of the primary concrete shield are quantified in this paper.