Space-Energy Few-Group Neutron Cross Sections for Large, Complex Core Calculations

A procedure is developed to generate space-energy corrections to few-group infinite medium cross sections and to apply them in a complex core geometry. Strategy is discussed for using these cross sections in large three-dimensional diffusion theory calculations with burnup. The many practical questions that arise when trying to apply one-dimensional corrections to three-dimensional calculations with several hundred regions are dealt with. The method is being used to obtain accurate predictions of core behavior for the light water breeder reactor.