Status of pseudo fission-product cross sections for fast reactors. Results of the SWG17

A computational benchmark was defined where participants were asked to calculate pseudo fission-product cross sections, using their own multi-group structure and given concentrations for the fissile nuclide 239Pu. A micro flux weighting spectrum, typical for a fast power reactor has been supplied pointwise, but it was not strictly necessary to use it for the generation of multi-group constants, to avoid large amounts of work. The participant could also use its own library with a probably different weighting spectrum. However, the weighting spectrum was obligatory for the condensation to one-group cross sections. In a later phase also a poinwise adjoint flux spectrum was specified to allow for reactivity worth calculations. The results requested were: multi-group pseudo cross sections, one-group pseudo cross sections and reactivity worth, mainly for capture and inelastic scattering. For further interpretation also the one-group cross sections of the individual fission products were requested. All data necessary to perform the benchmark are included in this report. Almost all results are reproduced. (orig./DG)