压水堆相邻燃料棒间的高阶共振干涉现象研究

Study of High-Order Resonance Interference Effect between Adjacent Fuel Rods in Pressurized Water Reactor

针对压水堆中不同燃料类型相邻的燃料组件中的出现的高阶共振干涉现象进行了研究。通过超细群求解慢化方程和嵌入式共振计算方法,对该类问题进行了计算。通过对精细能谱形状和多群共振截面计算误差的分析,结果表明,高阶共振干涉现象随着慢化剂密度降低而增强,对共振计算的精度有一定的影响。在二氧化铀(UO2)与钚铀氧化物混合燃料(MOX)的混合组件中,截面的最大相对误差达10%。通过对嵌入式共振计算方法进行改进,可以有效地处理该共振干涉现象,提高具有复杂设计的燃料组件的共振计算精度。结果表明,在多种工况下的多燃料混合组件中,共振截面的相对误差降低至3%以下。

In the fuel assmebly of the presurized water reactor, the high-order resonance interference effect between adjacent fuel rods of different fuel types is studied. Based on the method of solving ultra-fine-group slowing-down equation and the embedded resonance calculation method, the specific type of problems is calculated. Numerical results show that the high-order resonance interference effect increases with the reduction of the moderator density and has some influence on the precision of resonance calculation. The maximum relative cross section error reaches 10% in the fuel assembly mixed with uranium dioxide fuel and plutonium uranium oxide fuel. By improving the embedded resonance calculation method, the high-order resonance interference phenomenon can be treated effectively, and the resonance calculation precision of the fuel assembly with complex design can be improved. Results show that the relative error of the resonant section is reduced to less than 3% in the multi-fuel mixing components under various working conditions.