基于二维广义横向积分综合一维半解析的三维中子扩散节块法

目前, 轻水堆堆芯计算广泛采用基于横向积分技术的中子扩散方程节块展开法, 该方法需要对横向泄漏进行多项式近似而不严格, 而且堆芯设计还需要额外的精细功率重构模块用于获得组件内各栅元的功率分布。本文提出两维广义横向积分方法, 直接采用源展开以及表面流耦合方法, 可以避免上述两个不足。由于反应堆堆芯不均匀性更多发生在径向, 因此采用径向基于广义横向积分方法结合轴向常规节块法的综合方法进行三维中子扩散计算。通过基准问题的数值计算, 验证了该方法对于堆芯扩散计算的正确性和可行性。

A Three-dimensional Neutron Diffusion Nodal Solver Based on 2D Generic Transverse Integrate Fused with 1D Semi-analytical Nodal Method

The nodal expansion method (NEM) based on transverse integrated technique is widely used in liquid water reactor core design. It uses an empirical transverse leakage polynomial approximation. Furthermore, it requires pin power reconstruction model for pin power within the assembly. A generic transverse integrate proposed in this work avoids the above shortages. Since the core heterogeneous usually happens in radial direction, the 3D neutron diffusion equation is solved with 2D generic transverse integrate fused with traditional 1D semi-analytical nodal method. With IAEA 2D/3D benchmark problem, the method is demonstrated correct and feasible for core neutron diffusion calculations.