Optimization analysis of the production process based on WIMS format multigroup nuclear data

Background: NJOY is used widely nuclear data processing program that can convert the data format of ENDF/B nuclear database into WIMS format of the multi-group cross section database. Purpose: This study aims to produce a multi-group database of WIMS-D format on the basis of the latest release of nuclear evaluation library ENDF/B-VII.1 by using nuclear data processing program NJOY-99. Methods: In allusion to basic fuel cell homogenization calculation benchmark problem of the light water reactor (LWR), taking the ²³⁵U and ²³⁸U nuclide as the main objects of analysis, the effect on processing time of making cross section library, as well as integral parameters ΔK_eff and data sensitivity of selecting input parameters of the NJOY program were compared and analyzed, which optimized the option of input parameter. Results and Conclusion: The results of validating on benchmark problems showed that the production of the multi-group database was correct, which embodied the high accuracy of calculation and provided the basis data of fuel assembly homogenization calculation for pressurized water reactor. (authors)