ABSTRACT

The multi-group cross-section generation capability for neutrons is implemented in the FRENDY nuclear data processing code. ACE-formatted files are used as the source of nuclear data instead of ENDF-formatted files since FRENDY already has the capability to generate pointwise cross sections in the ACE format. The several distinguished features are implemented for the multi-group generation capability, e.g. explicit consideration of resonance interference effect among nuclides, enhanced resonance treatment for various nuclear reactions, and accurate numerical integration of thermal cross sections. Verification calculations of the newly implemented capability are carried out through the comparison with the NJOY nuclear data processing code. Cross-section generations for all nuclides in JENDL-4.0, -4.0u, -$5\alpha 4$, ENDF/B-VII.1, -VIII.0, JEFF-3.3, and TENDL-2019 are carried out without unexpected processing issues, except for Pu-238 of TENDL-2019 that includes inconsistent data. The verification results indicate that the multi-group cross sections generated by FRENDY are consistent with those generated by NJOY. Now FRENDY can generate not only the pointwise cross sections for continuous energy Monte-Carlo codes but also the multi-group cross sections for deterministic neutronics analysis codes.

摘要

FRENDY 核数据处理代码中实现了中子的多组截面生成能力。ACE 格式的文件被用作核数据的来源，而不是 ENDF 格式的文件，因为 FRENDY 已经能够以 ACE 格式生成逐点横截面。实现了多组生成能力的几个显着特征，例如明确考虑核素之间的共振干扰效应，增强对各种核反应的共振处理，以及热截面的精确数值积分。通过与NJOY核数据处理代码的对比，对新实现的能力进行验证计算。JENDL-4.0、-4.0u、-中所有核素的横截面代数$5\alpha 4$、ENDF/B-VII.1、-VIII.0、JEFF-3.3 和 TENDL-2019 的执行没有意外的处理问题，除了 TENDL-2019 的 Pu-238 包含不一致的数据。验证结果表明，FRENDY 生成的多组横截面与 NJOY 生成的一致。现在，FRENDY 不仅可以生成连续能量蒙特卡罗代码的逐点截面，还可以生成确定性中子学分析代码的多组截面。