THE USE OF MULTI-GROUP TRANSPORT PROGRAMMES FOR THERMAL SPECTRUM CALCULATIONS ON PRESSURE TUBE REACTORS

摘要

This report describes developments in the technique of using multi-group transport theory programmes for calculating the thermal spectra in water lattices, and compares theoretical predictions with the fine structure and spectrum characterisation measurements made in the H20/D20 coolant loop of ZEEP. The developments concern the choice of energy group boundaries and the weighting spectrum which should be used when producing group averaged cross-sections, and methods of producing the source of neutrons into the thermal region.