OECD/NEA Burnup Credit Calculational Criticality Benchmark Phase I-B Results

SCALE 5.1 Predictions of PWR Spent Nuclear Fuel Isotopic Compositions

“…The measurement data for ATM-104 served as the basis of an irradiated fuel benchmark for criticality calculations 35 and was used for the OECD/NEA burnup credit criticality safety calculation benchmark Phase I-B. 82 The SFCOMPO database currently does not include the lanthanide measurements made at PNL or KRI used in the current report. …”

Review and Prioritization of Technical Issues Related to Burnup Credit for LWR Fuel

“…Previous work has demonstrated that the ORIGEN2 code could not provide the needed accuracy in the actinide inventory over the range of burnup and fuel designs, while some reactor physics codes did not track sufficient nuclides to provide accurate inventories after significant decay times. Although the SAS2H approach has some shortcomings, it has been shown to do remarkably well for PWR fuel, 16,24,25 and reasonably well for more heterogeneous (e.g., enrichment and absorber rod variations) BWR designs. 26,30 Results of PWR depletion problems solved by the OECD Working Group 16,18 indicate good agreement between SAS2H and a variety of codes, including those that use 2-D geometries in the assembly design.…”

“…Although the SAS2H approach has some shortcomings, it has been shown to do remarkably well for PWR fuel, 16,24,25 and reasonably well for more heterogeneous (e.g., enrichment and absorber rod variations) BWR designs. 26,30 Results of PWR depletion problems solved by the OECD Working Group 16,18 indicate good agreement between SAS2H and a variety of codes, including those that use 2-D geometries in the assembly design. However, for BWR fuel designs, initial comparison of SAS2H with 2-D codes 30,67 indicate differences that need to be further investigated and understood to determine the impact of the geometry modeling on the discrepancies.…”

“…Within the OECD Working Group, 16 depletion calculations were performed for three burnups for a pin-cell based on a pin from a CE 14×14 PWR. Comparisons were made on a nuclide by nuclide basis for each burnup case.…”

Review of studies on criticality safety evaluation and criticality experiment methods

“…IB Isotopic Prediction [36] This report summarizes the results and findings of the Phase IB benchmark, which was proposed to provide a comparison of the abilities of different code systems and data libraries to perform depletion analysis for the prediction of spent fuel isotopic concentrations. Results included here represent 21 different sets of calculations submitted by 16 different organizations worldwide and are based on a limited set of nuclides determined to have the most important effects on the neutron multiplication factor of light-water-reactor spent fuel.…”