蒙特卡罗中子输运程序用于反应堆设计与安全分析计算及校验时,微小的反应性扰动容易被统计涨落所掩盖,因此一般通过微扰计算处理此类问题。基于微分算子方法在JMCT程序中实现了反应性微扰计算功能。为保证计算的精度,JMCT考虑了非源扰动的高阶效应以及一阶裂变源扰动效应。选取了具有全局扰动、局部扰动的快中子与热中子裂变系统对JMCT反应性微扰计算功能进行了测试。测试系统覆盖了正负反应性变化。

In reactor design and safety analysis, the statistical error of Monte Carlo code often covers the actual reactivity difference between two systems with only a little difference. Generally, perturbation method is used to solve this problem. In this work, reactivity perturbation is implemented into JMCT code. High order perturbations and fission source perturbation are considered in order to get a high precision. Models with global perturbation and local perturbation are tested. The systems with fast and thermal neutron spectrum are also tested. Some of the above models have positive reactivity perturbations, while others have negative perturbations.