基于平面通量展开的三维Pin by Pin输运SP3计算

基于Pin by Pin输运SP₃计算是下一代反应堆物理计算方法中一个重要的研究方向。节块法一般采用高阶通量和中子源展开以适应较大的节块尺寸，因此对于Pin by Pin计算来说效率偏低。由于反应堆堆芯不均匀性更多发生在径向，本文提出一种径向基于二维平面通量展开结合轴向常规节块法的综合方法进行三维Pin by Pin输运SP₃计算，其三个方向的节块耦合迭代均采用基于中子净流耦合的格式。通过IAEA 2D/3D基准问题和典型输运基准问题计算，验证该计算方法对于堆芯扩散计算和输运计算的正确性和可行性。

A Plane Flux Expansion Solver for Three-dimensional Pin by Pin SP3 Method

Transport SP₃ based on pin by pin is an important anticipant in next generation reactor physics numerical methods. The nodal method for pin by pin calculation is not efficient because higher order flux and source expansion is assumed for large nodal size. Since reactor core heterogeneous happens usually in radial direction, a radial 2D plane flux fused with axial traditional nodal method is proposed for 3D pin by pin transport SP₃ calculation. A nodal iterations strategy based on nodal face current is adopted in all three directions. With IAEA 2D/3D and typical transport benchmark problem, the method is demonstrated correct and feasible for core transport and diffusion calculations.