Dose rate profile inside the spent fuel storage pool in case of full capacity storage

Abstract

This study aims to evaluate the radiation dose rate distribution inside temporary spent fuel open-pool storage. The storage pool is connected to the main pool via transfer channel to facilitate transporting the spent fuel under water that avoiding radiation dose rising in the working area in the reactor. The storage pool was prepared to store 800 spent fuel elements that considering the maximum capacity of storage. The spent fuel elements in the storage pool have different decay times depending on the times of extraction from the core. Assuming conservatively, that the spent fuels of the 5-years decay time would be stored in the lower rack and the spent fuels, of decay time ranged between 10 days and 5 years, would be stored in the upper rack. The dose rate was profiled in the region above the upper rack using SCALE/MAVRIC code applying adjoint flux calculation as a variance reduction technique. The results show that the dose rate values in the region above the pool surface would be lower than the permissible limits.