Flow Distribution Optimization Design of Certain Integrated Pool Lead-Bismuth Reactor

Abstract

Abstract The core inlet flow distribution of core is of great importance in the integrated pool lead-bismuth reactor design, while the integrated pool structure feature and lead-bismuth fluid bring difficulties to the flow distribution optimization. The result of flow distribution will directly affect the safety margin of thermal-hydraulic design: mal-distribution could lead to decrease of core thermal safety margin, which may cause negative effect on the reactor safe operation. Based on three-dimensional computational fluid dynamics (CFD) simulation, the flow distribution result is evaluated. It’s found that the eddy flow at the core entrance will lead to nonuniformity of flow distribution and flow fluctuation. Optimizations of design structure are conducted to improve the flow distribution characteristic. Different options of flow channel and flow distribution device design are proposed. By means of steady and transient calculation, the optimization options are evaluated from the two aspects: the uniformity and the stability of flow distribution. The local resistance loss and flow velocity are considered at the same time. At the end of the research, the structural design scheme which has better flow distribution characteristic and meets the restriction of local resistance loss and flow velocity is put forward. The research could provide reference to the thermal-hydraulic design of integrated pool lead-bismuth reactor.