基于定量重要性分析的燃耗链压缩方法

摘要

The depletion calculation in reactor physics requires depletion chain data.However,the depletion chain that origi-nates from evaluated nuclear data library is unnecessarily detailed for assembly and micro-depletion calculation,while conventional depletion chain compression methods are semi-empirical with limited application scope and accuracy.In this paper,a method that compresses depletion chain based on quantitative significance analysis of each nuclide and reaction channel is proposed.The signifi-cance analysis uses fine depletion chain computation results of representative problems as data source,and it is carried out by eval-uating the influence on neutron absorption,production and number densities of target nuclides,induced by each basic unit com-pression.The method is applied to depletion chain compression in the context of PWR assembly calculation.Fine and compressed depletion chain computations of selected test cases are performed.The comparison among obtained numerical results show that, while preserving accuracy requirements,the proposed depletion chain compression method is capable of significantly reducing the complexity of the depletion chain,and the demanded storage and time savings are achieved consequently.%核反应堆物理计算中的燃耗计算需要使用燃耗链,但是评价核数据库所定义的燃耗链对于组件计算以及堆芯微观燃耗计算过于精细,传统的燃耗链压缩方法大都是半经验性的,适用范围和精度有限.提出了一种通过定量评估各核素与各反应道重要性实现压缩燃耗链的方法.重要性分析的数据基础是代表性问题的精细燃耗链计算结果,方法是考察每一个单元压缩操作对中子吸收、中子产出以及目标核素原子核密度的影响.该方法被应用于压水堆组件计算中燃耗链的压缩,随后分别应用精细燃耗链和压缩燃耗链对选取的验证算例进行了计算.结果的对比分析显示,在保证计算精度需求的前提下,该燃耗链压缩方法能够显著降低燃耗链规模,满足节省存储开销和时间的需求.