Proper Use of the Nordheim Integral Treatment for Resonance Processing

摘要

The Nordheim integral treatment is an approximate method for determining the neutron spectra within materials containing resonance cross sections. These spectra are necessary to determine the flux-weighted multigroup data properly. In practice, the resonance material multigroup cross sections produced by use of Nordheim-generated spectra are combined with other multigroup cross sections, and further energy and spatial collapsing of the data is performed. The question arises of whether performing this spatial collapse following the Nordheim treatment constitutes double spatial weighting. To investigate this possibility, results were compared with those for a second method of forming the multigroup cross section data, and with the results of a fine-group calculation. It was concluded that the first method above is the procedure to follow for the proper use of the Nordheim integral treatment. 1 table. (ERA citation 05:023298)