A novel SN/MOC collaborative method for few-group cross-section generation with versatile neutron spectral adaptability in advanced reactor physics analysis

This study proposes a novel deterministic discrete ordinate method (S-N)/method of characteristics (MOC) collaborative method for few-group cross-section generation to realize versatile spectral computation for different types of neutron energy spectra. The method encompasses fast/intermediate/thermal spectra, which facilitates advanced reactor physics analysis. The S-N with multi-direction scanning was initially used to compute the region-wise isotope-dependent background cross-sections to accommodate the complicated spectral features over the entire energy range and obtain the fine-group cross-sections. The MOC was then adopted to acquire accurate weighting spectra over the entire domain for few-group cross-section generation. As a practical application, the proposed method was implemented in AVENUE code development, which was employed for the reactor physics analysis of typical fast/thermal spectra, over-moderated thermal spectra, and complicated intermediate spectra with additional parallelization and acceleration techniques. The verification results revealed that the proposed S-N/MOC collaborative method enables accurate few-group cross-section generation with versatile spectral adaptability. (C) 2022 Elsevier B.V. All rights reserved.