LANL Critical Benchmark Comparison Study and Subsequent Revision for Cases Involving LEU and MIX

Technical Report · Thu Jul 01 04:00:00 EDT 2021

DOI:https://doi.org/10.2172/1897978· OSTI ID:1897978

Alwin, Jennifer ^[1]; Leclaire, Nicolas ^[2]; MacQuigg, Robbie ^[1]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2. Inst. for Radiological Protection and Nuclear Safety (IRSN), Fontenay-aux-Roses (France)

As part of an international collaboration within the DOE Nuclear Criticality Safety Program (NCSP), LANL is involved in a comparison study to quantify differences in k-effective results from neutron transport simulations of critical benchmark experiments. The DOE NCSP Mission and Vision details the activity in which the French Institut de Radioprotection et de Sûreté Nucléaire (IRSN) leads the study with LANL, ORNL, and LLNL to compare results of various neutron transport codes and nuclear data libraries for ICSBEP benchmarks held in common by the entities. The task statement from the DOE NCSP Five-Year Execution Plan is given as: "The proposal is for IRSN to lead a new intercomparison based on the MORET code with the latest JEFF-3.3 data and ENDF/B-VIII.0 data, when available, using their existing comprehensive selection of 2,714 benchmarks and collate their results together with those from LLNL (COG), LANL (MCNP) and ORNL (SCALE). Due to the large number of benchmarks involved, this effort is envisioned to take three years with an additional year for IRSN to complete a summary report. The benchmark development will be performed independently to minimize modeling errors through discovery and resolution of discrepant results. A summary report will be generated (led by IRSN) to document the results of this study." This report documents results obtained for revisions made to cases involving Intermediate Enriched Uranium (IEU) and a mixture of Pu and Uranium (MIX), with a focus on the changes made to LANL benchmarks modeled with MCNP6 using ENDF/B-VII.1 nuclear data that appeared to have discrepant results when compared with results of other codes. Feedback was used to pinpoint review of particular benchmark input files and to revise them when necessary. This report documents the results of review and revision of specific benchmarks highlighted as possibly discrepant in the comparison study. In addition, there is an effort tied to this work involving collaboration between LANL XCP and NCS Divisions in the development of a shared review/revision procedure and use of a new benchmark repository.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP)
• DOE Contract Number: 89233218CNA000001
• OSTI ID: 1897978
• Report Number(s): LA-UR-21-29454
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
96 KNOWLEDGE MANAGEMENT AND PRESERVATION
Analytical Methods
Intermediate Enriched Uranium (IEU)
MCNP6
Mixture of Pu and Uranium (MIX)
Nuclear Criticality Safety Program (NCSP)
Whisper-1.1