During the loading and refueling of Pressurized Water Reactor (PWR), Sb-Be secondary neutron source is generally used to induce fission reaction to increase ex-core detector signal, which could eliminate the monitoring blind area. In order to obtain the optimal position of secondary neutron source which would lead a maximum signal, it is necessary to evaluate the contribution of secondary neutron source at different potential positions. Based on CAP1400 PWR model, Discrete ordinate (S_N) adjoint transport method has been studied by using 199 groups fine cross section. Fission source contribution is simulated by controlling outer iteration in adjoint transport calculation. The contribution of secondary neutron sources at different potential positions has been analyzed. Monte Carlo (MC) forward calculation has been used as a comparison, and the two results are in good agreement with each other. Through the analysis, secondary neutron source optimal location in reactor core can be obtained. The innovative method can provide a reference for the layout optimization of secondary neutron source.

在压水堆（PWR）的装料和加油过程中，通常使用Sb-Be二次中子源引起裂变反应，以增加岩心探测器的信号，从而消除监测盲区。为了获得将导致最大信号的次级中子源的最佳位置，有必要评估次级中子源在不同电位位置的贡献。基于CAP1400 PWR模型，离散坐标（S _N）已经使用199组细截面研究了伴随运输方法。通过控制伴随输运计算中的外部迭代来模拟裂变源的贡献。分析了次级中子源在不同位置的贡献。蒙特卡罗（MC）的正向计算已用作比较，并且两个结果彼此吻合良好。通过分析，可以获得反应堆堆芯中子源的最佳位置。该创新方法可为二次中子源布局优化提供参考。