Abstract NECP-Hydra is a three-dimensional high-performance parallel code for reactor core analysis and radiation shielding calculation. This paper summarizes its main features and carries out some verifications. NECP-Hydra empolys finite difference and discrete ordinates for spatial and angular discretization respectively, and it supports both rectangular and cylindrical geometry. The parallelization calculation was performed by the Koch-Baker-Alcouffe (KBA) algorithm based on domain decomposition. Besides existing four-octant sweep (FOS) scheme, a diagonal-octant sweep (DOS) scheme is proposed to further improve the efficiency for the problems with reflective boundaries. Moreover, acceleration methods such as parallel mesh-corner DSA acceleration, inner-group GMRES and multi-group GMRES are also implemented in the code to reduce the computational time. Additional function like continuing computation with surface source for coupling with Monte-Carlo code is also implemented. Finally, we present some numerical results for evaluating NECP-Hydra’s accuracy, efficiency and its preformance in practical analysis of reactors, from which we can draw a conclusion that NECP-Hydra achieves both high accuracy and efficiency throughout these verifications.

中文翻译：

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NECP-hydra：用于核心分析和屏蔽计算的高性能并行 S 代码

摘要 NECP-Hydra 是一种用于反应堆堆芯分析和辐射屏蔽计算的三维高性能并行代码。本文总结了其主要特点并进行了一些验证。NECP-Hydra 分别为空间和角度离散化采用有限差分和离散坐标，它支持矩形和圆柱几何。并行化计算由基于域分解的 Koch-Baker-Alcouffe (KBA) 算法进行。除了现有的四八分圆扫描（FOS）方案外，还提出了对角八分圆扫描（DOS）方案以进一步提高反射边界问题的效率。此外，平行网格角DSA加速等加速方法，代码中还实现了内组 GMRES 和多组 GMRES 以减少计算时间。还实现了附加功能，例如使用表面源继续计算以与蒙特卡洛代码耦合。最后，我们提供了一些数值结果，用于评估 NECP-Hydra 在反应堆实际分析中的准确性、效率及其​​性能，从中我们可以得出结论，NECP-Hydra 在这些验证过程中实现了高精度和高效率。