RFSP-IST Simulation of Fuel Transient During Refuelling of the ACR-1000 Reactor

Abstract

Similar to the CANDU reactors, the ACR-1000 reactors will use on-power refuelling to maintain long-term reactivity control. During the fuelling operation, the power transients, mainly in the channel being refuelled, are induced as the fresh and irradiated fuel bundles are shifted in and out of high flux regions in the core. This refuelling shift transient has been simulated with the *SIMULATE module of RFSP-IST to derive bundle and channel power transients with spatial flux tilt and bulk reactivity control accounted for. Moreover, to capture possible short-term time-dependent effects, a coupled kinetics-thermal hydraulic dynamic simulation using the *CERBERUS module of RFSP-IST has also been performed. In this paper, the model and methodology of the refuelling simulation will be discussed. Results will be presented.