基于BP神经网络的反应堆堆外探测器响应快速分析方法研究

Research on Rapid Analysis Method of Ex-core Detector Response Based on BP Neural-network Algorithm

堆外探测器响应描述了中子注量率与电流信号之间的对应关系,对反应堆的安全运行有着至关重要的作用。针对确定论方法和蒙特卡罗方法均无法兼顾堆外探测器响应计算效率与计算精度这一问题,采用基于反向传播(BP)神经网络的算法完成堆外探测器响应的快速计算;基于堆芯核设计系统CMS对我国现有百万千瓦级压水堆堆芯进行物理建模,堆芯内燃料组件排布方式和燃耗变化作为BP神经网络的输入,相对应的燃料组件排布方式以及不同燃耗下的堆外探测器响应作为BP神经网络的输出,构建了3层BP神经网络模型并进行了优化;经过计算验证,优化后模型能够较为快速地计算堆外探测器响应,且预测值与堆芯核设计系统CMS计算值相比误差较小,有较好的工程应用前景,为计算堆外探测器响应提供了新思路。

The response of the ex-core detector describes the corresponding relationship between neutron fluence rate and current signal,which plays a crucial role in the safe operation of the reactor.In response to the problem that both deterministic and Monte Carlo methods cannot balance computational efficiency and accuracy in calculating the response of ex-core detectors,a back propagation(BP)neural network algorithm is used to quickly calculate the response of ex-core detectors.Based on the core design system CMS,the physical modeling of the existing million-kilowatt pressurized water reactor core in China was carried out.The fuel assembly arrangement and burnup changes in the core are used as the inputs of the BP neural network,and the corresponding fuel assembly arrangement and detector responses outside the reactor under different burnup are used as the outputs of the BP neural network.A three-layer BP neural network model is constructed and optimized.After calculation verification,the optimized model can quickly calculate the response of the ex-core detector,and the predicted value has a smaller error compared to the core design system CMS calculation value.It has good engineering application prospects,providing a new idea for calculating the response of the ex-core detector.