| As one of the important equipment in the closed nuclear fuel cycle,the nuclear fuel reprocessing plant can realize the nuclear fuel cycle utilization and the effective disposal of nuclear waste,so its safety has attracted great attention.It’s importance to study the safety characteristics of key equipment in reprocessing plants under critical accidents.Nuclear pulverized fuel system is the key equipment of reprocessing plant.This paper took it as the research object and carried out the research on nuclear thermal coupling according to its operating characteristics under transient conditions.First,based on the two-fluid model theory,two Phase Euler Foam solver in OpenFOAM was used to carry out numerical simulation for the experimental model of fluidized beds developed by Taghipour et al.,and Fujun Yang et al.,and the results show that the solver is mature in predicting fluidization phenomena.Then the neutron diffusion program based on the finite volume method was used to calculate benchmark problems,which verified the correctness of the diffusion program.Finally,the nuclear thermal coupling program was developed based on the neutron diffusion theory and Euler-Euler method using OpenFOAM,which was able to solve the conservation equation of multiple physical fields simultaneously.Multiple physical fields can share data with highprecision and large-scale parallel computing.The Coupled Neutronics and Thermal-Hydraulics Simulation for nuclear pulverized fuel was studied,which predicted the pulverized fuels’ behaviors of transient supercritical accidents: When the supercritical accident occurs,the power increases causing the accumulation of fission heat.The phenomenon results in the air in the pulverized fuel gap to be heated.And the pulverized fuel will be fluidized,which will lead to the reduction of the power density in the system.After that the system will return to the sub-critical condition.The results of numerical study in this paper can provide theoretical support for shielding and emergency response in reprocessing plants and provide reference value for improving the safety margin of two-phase system. |
