Partially closed nuclear fuel cycle strategy integrating a NuScale-like reactor and an Accelerator Driven System (ADS)

This study proposes a partially closed nuclear fuel cycle that integrates a NuScale-like reactor with an adapted Accelerator-Driven System (ADS) through a three-stage approach. NuScale first produces spent fuel, which is reprocessed using the GANEX technique and loaded into the ADS-SMR, a smaller version of the ADS reactor geometrically adapted to match the NuScale dimensions and to incorporate the seed-blanket-unit (SBU) concept. Initially, the ADS-SMR arrangement contains reprocessed fuel in the seed region and thorium dioxide in the blanket region, aiming at fuel regeneration. This thorium-after-breeding fuel is then progressively loaded back into the three batch positions of the NuScale core designed for fresh fuel insertion during reshuffling, thereby resulting in three models with distinct fuel loading patterns. Results showed that the effective multiplication factor from the ADS-SMR dropped slightly over ten years, even without additional fissile input during the operation time. It also generated significant 233 U, reaching about 5.82 wt% fissile content. Back to the NuScale reactor, the three models exhibited early criticality increases due to in-situ fissile breeding, with one of the models nearly doubling energy output per kgHM compared to the reference case. Overall, the study highlights a feasible path for a partially closed nuclear fuel cycle strategy integrating ADS and SMR technologies. The Serpent code version 2.1.32, developed by VTT, and the ENDF/B-VII.0 nuclear data library have been used to perform the simulations.