A dataset of higher-order modes results obtained by the hybrid two-step method

Based on the higher-order modes diffusion calculation code HARMONY, we developed a new higher-order modes calculation code HARMONY2.0 using the MC-deterministic hybrid two-step strategy. In the HARMONY2.0, the mesh homogenized multigroup constants are obtained by OpenMC in the first step, then higher-order modes are calculated with the mesh homogenized core diffusion model using Implicitly Restarted Arnoldi Method. In addition, to improve the calculation efficiency in particularly large higher-order modes, event-driven parallelization / domain decomposition methods are embedded in the HARMONY2.0 code to accelerate the inner iteration of λ/α mode by using OpenMP. Furthermore, the higher-order modes of the complex geometric models, such as Hoogenboom and ATR reactor for λ mode and MUSE-4 experiment facility for prompt α mode, are computed in diffusion theory.

本研究基于高阶模态（higher-order modes）扩散计算程序HARMONY，采用蒙特卡洛-确定性混合两步策略，开发了全新的高阶模态计算程序HARMONY2.0。在HARMONY2.0中，第一步通过OpenMC获取网格均匀化多群常数；随后，借助隐式重启阿诺尔迪法（Implicitly Restarted Arnoldi Method），基于网格均匀化堆芯扩散模型完成高阶模态的计算。此外，为提升超大型高阶模态的计算效率，程序内置了事件驱动并行化/区域分解方法，并通过OpenMP加速λ/α模态的内迭代过程。本研究还采用扩散理论，针对复杂几何模型开展高阶模态计算，其中包括用于λ模态计算的胡根布姆（Hoogenboom）基准题与ATR反应堆（ATR reactor），以及用于瞬发α模态（prompt α mode）计算的MUSE-4实验装置（MUSE-4 experiment facility）。