Sensitivity neutronic analysis of accident tolerant fuel concepts in APR1400

Zirconium-based cladding materials used in nuclear power plants have been shown to pose safety concerns due to their susceptibility to oxidation and hydrogen production during high-temperature conditions, such as loss-of -coolant accidents. In order to address these concerns, alternative cladding materials that are more resistant to these conditions are being explored. This study investigates the potential of using silicon carbide (SiC) and iron -chromium-aluminum (FeCrAl) cladding materials to improve the safety and efficiency of nuclear power plants, particularly in the context of accident tolerant fuel (ATF) technology concepts. The study utilized Serpent Monte Carlo 2.31 to conduct neutronics analyses on the APR-1400 reactor, assessing the impact of SiC and FeCrAl cladding materials on fuel reactivity, neutron spectrum, Pu-239 inventory, and pin power distribution. A sensitivity analysis was conducted by adjusting parameters such as fuel enrichment, cladding thickness, and pellet diameter to determine the effects of the new materials on design parameters. Results of the analysis revealed that, by adjusting design parameters, SiC and FeCrAl materials could be used to meet the cycle length of the original fuel-cladding (zircalloy). Furthermore, using SiC cladding resulted in a hardening of the neutron spectrum, which increased the production of actinides such as plutonium. By analyzing the effects of changing parameters, including fuel enrichment, fuel geometry, and cladding material, the study concludes that SiC is a feasible substitute for conventional zirconium cladding. The findings of this study have practical implications for the safety and efficiency of nuclear power plants. The use of SiC and FeCrAl cladding materials could signifi-cantly reduce the risks associated with loss-of-coolant accidents and other high-temperature conditions, thereby improving the safety and reliability of nuclear power plants.