On the Preparation of Library Data for an Implementation of the Method of Subgroups in WIMS-AECL

Abstract

The subgroups method of calculating self-shielded resonance cross sections, and the start of an implementation of it for WIMS-AECL, are described in a companion paper [1] published in these proceedings. The current, ongoing development follows closely the earlier works of Nikolaev et al. [2], Gregory [3] and Roth [4]. A new program called SGFIT processes ENDF/B-based nuclear data for nuclides exhibiting cross-section resonances, and it generates subgroup parameters consistent with an existing WIMS-AECL energy-group structure. Design aspects of SGFIT are described in this work. Some details of sample calculations made for 91Zr are presented.