Performance analysis of irradiated thermo-mechanical coupled petal-shaped fuel rod under different power and heat transfer conditions

As a new type of fuel rod, petal -shaped fuel rod (PSFR) has the advantages of lowering the core temperature and increasing the power density, and thus has a application prospect. Based on the thermal elastic-plastic theory, this paper establishes an analytical model for irradiated thermal-mechanical coupling performance of PSFR by user subroutine. Through numerical simulations of the full -cycle operation of PSFR under different power and heat transfer conditions, the performance parameters of fuel rods, such as fuel rod temperature and stress, are obtained, and their spatial distribution and the variation pattern with the operation time analyzed. The results show that increasing line power leads to a simultaneous increase in fuel rod temperature, stress, maximum deformation, and creep. However, appropriate reduction in heat transfer coefficient decreases the cladding stresses. The above research results will provide an essential theoretical basis for determining new PSFR's deformation and operation risk.