锕系可燃毒物板状燃料组件燃耗特性研究

为研究锕系可燃毒物在板状燃料组件的燃耗特性和延长寿期的适用性，本研究以不同富集度的板状燃料为对象，计算分析了相同初始组件无限增殖因数（kinf）情况下的锕系可燃毒物装载量、燃耗深度、235U利用率等。结果表明，在低富集度（4%~7%）情况下，240Pu可燃毒物在寿期内表现出较好的转换效应，235U利用率高，可起到延长堆芯寿期的作用；在中等富集度（25%~40%）情况下，240Pu可燃毒物的转换效应减弱，而231Pa可燃毒物表现出较好的转换效应；在高富集度（70%~97%）情况下， 231Pa可燃毒物的转换效应减弱，但含231Pa组件的235U利用率和达到的燃耗深度在所选锕系核素中最大；240Pu可作为长寿期低富集度燃料可燃毒物的选择，231Pa可作为长寿期中等、高富集度燃料可燃毒物的选择。 

Study on Burnup Characteristics of Actinide Burnable Poisons in Plate-Type Fuel Assembly

In order to study the burnup characteristics of actinide burnable poisons in plate-type fuel assembly and the feasibility of actinide burnable poisons in extending core lifetime, the burnable poison loading, burnup depth and utilization of 235U in plate-type fuel assemblies with different enrichments but same initial kinf were calculated and analyzed in this paper. The results show that, in the case of low enrichment (4%~7%), 240Pu burnable poison exhibits a good conversion effect during the lifetime, and the utilization of 235U is high, which plays a role in extending lifetime. In the case of medium enrichment (25%~40%), the conversion effect of the 240Pu burnable poison is weakened. The 231Pa burnable poison exhibits a better conversion effect during the lifetime. In the case of high enrichment (70%~97%), the assemblies containing 231Pa can achieve the deepest burnup and its utilization of 235U is also the highest, although the conversion effect of the 231Pa burnable poison is weakened. It can be concluded that, 240Pu can be used as the burnable poisons for the low enrichment fuel for long lifetime purpose. However, 231Pa is preferred for the circumstances of medium and high enrichment fuels.