Multigroup cross sections for reactor physics calculations generated on the basis of fundamental nuclear data

The Bet-up of a cross section generating code system based on fundamental nuclear data is described. The basic source of data is the UK Nuclear Data Library containing cross section tabulations for most of the materials important in Reactor Physics Calculations. Effective resonance cross sections calculated from resonance parameters are added together with thermal scattering data.

The applicability to light-water reactor systems of the group cross sections produced is demonstrated by means of calculationally simple test examples.