Steady-state and transient investigation of a small pressurized water reactor ACPR50S for different ATFs based on Bamboo-C code

摘要: Small modular reactors have received widespread attention owing to their inherent safety, low investment, and flexibility. Small pressurized water reactors (SPWRs) have become important candidates for SMRs owing to their high technological maturity. Since the Fukushima accident, research on accident-tolerant fuels (ATFs), which are more resistant to serious accidents than conventional fuels, has gradually increased. This study analyzes the neutronics and thermal hydraulics of an SPWR (ACPR50S) for different ATFs, BeO+UO2-SiC, BeO+UO2-FeCrAl, U3Si2-SiC, and U3Si2-FeCrAl, based on a PWR fuel-management code, the Bamboo-C deterministic code. In the steady state, the burnup calculations, reactivity coefficients, power and temperature distributions, and control-rod reactivity worth were studied. The transients of the control-rod ejection accident for the two control rods with the maximum and minimum reactivity worth were analyzed. The results showed that 5% B-10 enrichment in the wet annular burnable absorbers assembly can effectively reduce the initial reactivity and end-of-life reactivity penalty. The BeO+UO2 -SiC core exhibited superior neutronic characteristics in terms of burnup and negative temperature reactivity compared with the other three cases owing to the strong moderation ability of BeO+UO2 and low neutron absorption of SiC. However, the U3Si2 core had a marginally better power-flattening effect than BeO+UO2, and the differential worth of each control-rod group was similar between different ATFs. During the transient of a control-rod ejection, the changes in the fuel temperature, coolant temperature, and coolant density were similar. The maximum difference was less than 10◦C for the fuel temperature and 2 ◦ C for the coolant temperature.