Verification Of SCALE Modules Against CMS5/SNF Sequence For Depletion And Decay Calculations Of BWR Fuel Assemblies

This study presents code-to-code comparisons between the TRITON and Polaris modules of the SCALE code system and the coupled CASMO/SIMULATE/SNF (CMS5/SNF) code sequence for evaluating the isotopic composition of spent nuclear fuel on a long-term basis. The models are based on spent fuel assemblies from a Swiss boiling water reactor. The parameters for the comparisons are: nuclide vectors, total activity, neutron source, and decay heat starting from 2019 and up to 100,000 years of decay. Where notable, the deviations in fission products and actinides are discussed with respect to differences between the codes and models. Overall, the results proved to be in good agreement for the prediction of spent fuel nuclide vectors. Good consistency was observed for the total activity and decay heat power. Most fission products and actinides considered in this work are in good agreement, with few exceptions which show systematic deviations, e.g. Mo-93, Sn-121m, Am-242, Am-242m and Cm-242.