École Nationale Supérieure de
Techniques Avancées

Abstract

Cross sections are part of the basic nuclear data used in neutronics codes to quantify neutron-matter interaction. Prior to the use in criticality or reactor physics calculations, cross sections data need to be prepared in a form suitable for the computer code used. That is the matter of software such as NJOY (Los Alamos National Laboratory), CALENDF (CEA) or PREPRO (International Atomic Energy Agency). The French public expert of safety (IRSN) is developping its own tool for processing nuclear data, GAIA, that serves to cross-check the results of other existing codes. The aim of this report is to describe in detail the implementation of a module for the processing of cross sections in the unresolved resonance range. The method used relies on a slightly new way of producing probability tables which is then compared to the outcome of other existing nuclear data processing codes.