NECP-Atlas中多群常数处理模块的开发与验证

Development and Verification of Multi-Group Constants Processing Module in NECP-Atlas

多群常数是确定论物理计算的基础,多群常数的准确性将直接影响到后续确定论物理计算结果的可靠性。国内外多群常数处理方法发展迅速,研究多群常数处理方法以及开发相关程序具有重要意义。多群常数包含多群截面和多群转移矩阵以及多群裂变常数等参数。基于评价核数据库和反应率守恒原理,利用可递推的超细群方法求解中子慢化方程并提出了核素混合方法,开发了Group_collapse模块,实现了多群常数的处理功能。数值结果表明,理论模型正确,所处理的多群常数可用于传统两步法以及一步法的确定论物理程序。

Multi-group constants are the basis of the deterministic physics calculation, and the accuracy will directly affect the subsequent calculations. The methods of multi-group constants processing are developed rapidly, and the study on the processing methods and relevant code developing have great importance. Multi-group constants contain multi-group cross sections, transfer matrices, fission constants, etc. Based on the evaluations and the reaction rate conservation theory, the neutron slowing down equation is solved by the recursive hyper-fine group method and the nuclide mixing method is proposed. A module named Group_collapse for processing multi-group constants is developed. Numerical results show that the theories are correct, and the multi-group constants can be available for the deterministic physics codes which are based on the conventional two-step method and the one-step method.