Development and Verification of Multigroup Cross Section Generation Module GroupXS in AXSP

Abstract

It is important for nuclear reactor physics calculation to generate accurate multigroup cross section libraries by using evaluation nuclear data libraries. A new evaluated nuclear data library processing code, named as AXSP (Advanced Cross Section Processing Code) was developed with independent intellectual property rights. The GroupXS module was developed with the ability of generating multi-group cross-sections based on the Bondarenko method which is always a favorable approximation for the fast spectrum reactor, and the method was also used in GROUPR of NJOY. To verify the accuracy of the GroupXS module, the GROUPR module of NJOY was used, and we corrected three numerical verification bugs of GROUPR. The bugs were described in this study. By comparing the calculation results with GROUPR of NJOY2016, the relative error of multigroup flux, multigroup cross sections of various reaction types are less than 0.01%, and the relative errors of transfer matrices of various reaction types are basically less than 0.1%. All the neutron reaction types of all nuclides in ENDF/B-VII.1, ENDF/B-VIII.0 and CENDL-3.2 can be processed by GroupXS, and the multigroup cross sections generated by GroupXS of AXSP have a good agreement with that generated by GROUPR of NJOY2016.