Abstract: A method for analyzing debris bed formation based on a multi-resolution multiphase particle algorithm, which uses the least-squares moving particle semi-implicit method with second-order computational accuracy and improves surface tension model and free surface particle identification model. The method also utilizes a particle-based gas-liquid phase transition model and a particle-based liquid-solid phase transition model with multi-resolution features, such that the coolant vaporization and melt solidification processes during the falling process of the melt can be calculated. Moreover, a solid-solid collision model is coupled to calculate the collision and debris bed deformation during the falling process of the debris particles. In this way, the momentum exchange, energy transfer and phase transition between different phases are taken into account, and the computational instability caused by the large physical difference between phases is mitigated.

Abstract: The invention belongs to the technical field of nuclear reactor materials design, and discloses a method for improving the withstanding capability of the cladding material in the fast neutron irradiation environment, comprising the following steps: selecting the cladding material with the annular structure and placing it on the outer side of the metallic fuel slug, with leaving a 0.2-0.8 mm gap between the metallic fuel slug and the cladding material; processing the operation in a reactor subsequently, with an annealing process of the fast neutron reactor fuel during the operation of the reactor; improves the withstanding capability of the cladding material in the fast neutron irradiation environment.

Abstract: The disclosure discloses a high-burnup fast reactor metal fuel, wherein the reactor core is loaded with metal fuel made of natural uranium alloy U-50Zr. The metal fuel manually controls the temperature to realize phase transition, increase burnup, and extend the service life of fuel; increases the fuel burnup to increase uranium utilization and reduce the pressure of disposing nuclear waste; extends the fuel life cycle to reduce nuclear power costs and improve the economy of nuclear energy; effectively carries out the timely release of fission gas and the periodic elimination of fuel defects, thus reducing the fuel-cladding mechanical interaction caused by swelling, and increasing the safety.