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DOE OSTI · 1735406

S/U Comparison Study with a Focus on USLs

Alwin, Jennifer L.·Brown, Forrest B.·Clarity, Justin B.·Duhamel, Isabelle·Fernex, Frederic·Leal, Luiz C.·Little, Robert C.·Marshall, William J.·Rising, Michael E.·Saylor, Ellen M.·Spencer, Kristina Y.
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Abstract

Under a DOE Nuclear Criticality Safety Program (NCSP) task involving Analytical Methods, three Laboratories collaborated in a comparison of results obtained from Sensitivity/Uncertainty (S/U) packages relevant to validation of transport codes. The task involves Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Los Alamos National Laboratory (LANL), and Oak Ridge National Laboratory (ORNL) comparing results of MORET 5/MACSENS V3.0, MCNP6.2/Whisper-1.1, and SCALE 6.2.3/TSUNAMI/USLSTATS respectively. All Monte Carlo transport code results utilize ENDF/B-VII.1. Four cases from the International Handbook of Evaluated Criticality Safety Benchmark Experiments (ICSBEP Handbook) were selected as application models: HEU-MET-FAST-013-001, HEU-SOL-THERM 001-008, PU-MET-FAST-022-001, and PU-SOL-THERM 001-001. Ultimately, comparison is made between Upper Subcritical Limits (USLs) obtained using each code package for each application case. Since differences exist in whether packages take into account margin of subcriticality (MOS), the USL may be computed using bias and bias uncertainty, also known as the calculational margin (CM) in ANSI/ANS 8.24. Application of portions of MOS to the USL for nuclear data uncertainty of and potential code margin is referred to as USL herein. In either case, additional MOS is considered for actual application cases.

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS97 MATHEMATICS AND COMPUTINGAnalytical MethodsCalculational Margin (CM)Evaluated Nuclear Data File (ENDF)Margin of Subcriticality (MOS)Nuclear Criticality Safety Program (NCSP)SCALETSUNAMIUpper Subcritical Limits (USLs)Whisper

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Alwin, Jennifer L., Brown, Forrest B., Clarity, Justin B., Duhamel, Isabelle, Fernex, Frederic, Leal, Luiz C., Little, Robert C., Marshall, William J., Rising, Michael E., Saylor, Ellen M., Spencer, Kristina Y.. 2020-11-16. S/U Comparison Study with a Focus on USLs. https://doi.org/10.13182/t123-33156

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