基于响应模块逆向优化的中子能谱调控方法研究

Research on Regulation method of Neutron Spectrum Based on Basic Response Module Inverse optimization

中子能谱是核能系统中的关键参数之一,直接影响系统的安全运行与经济性能。在中子学实验和部分核技术应用领域中,通常采用不同的材料模块来得到特定的中子能谱。但是,传统的方法基于人工经验对材料模块进行反复迭代设计,需要大量的计算资源和人力成本,且很难精准复现出所需能谱。本文发展一种基于响应模块逆向优化的中子能谱调控方法,该方法设计了标准化尺寸的响应模块,通过预计算对每个模块进行矩阵标定,创新地提出了一种基于离散响应矩阵的输出能谱快速计算方法,能够得到响应模块任意排列组合的输出能谱,结合智能优化算法,快速构建出能够复现指定能谱的中子调控方案。基于该方法,程序自动构建出了国际热核实验堆(ITER)活化实验能谱,与人工调控方案输出能谱相比,本文方法输出能谱更为准确的复现了目标能谱,其最大偏差降低一个量级。

Neutron energy spectrum is one of the key parameters in nuclear energy system, which directly affects the safe operation and economic performance of the system. In the field of neutronics experiments and some nuclear technology applications, different material modules are usually used to reproduce specific neutron spectrum. The traditional method is based on artificial experience,which requires a lot of calculation and verification,and it is difficult to accurately reproduce the energy spectrum which is necessary for the experiment. In this paper,a method of regulation of neutron energy spectrum based on basic response module inverse optimization is developed. This method designs the basic response module with certain size,and pre-computing each response unit for matrix calibration,it innovatively realizes a fast calculation method of regulation results based on the discrete response matrix. Finally computing the output energy spectrum of each regulation scheme that is the arrangement and combination of basic response module,a neutron regulation scheme for special energy spectrum can be constructed quickly with intelligent optimization algorithm. Using the above method,the energy spectrum control scheme for ITER activation experiment of national thermonuclear reactor is reconstructed. Comparison of the target energy spectrum, the regulation energy spectrum is much closer than the manual results and the max deviation is reduced by an order of magnitude.