Speaker
Description
Code to code comparison is a widely used approach for verification, validation, and benchmarking in nuclear reactor physics analyses. Such exercises typically require that the participating code to employ a common or a common-source nuclear data library in order to ensure consistency and isolate code specific effects. Furthermore, high fidelity Monte Carlo neutron transport simulations and nuclear safety analyses impose stringent requirements on nuclear data libraries to support a wide range of material temperatures and operating conditions. Consequently, careful assessment of open source multi temperature nuclear data libraries has become essential, including evaluation of available temperature grids for fast continuous energy ACE files, coverage and temperature resolution of thermal scattering data (S(α, β; T)) and support for advanced treatments such as Doppler Broadening Rejection/Resonance Correction (DBRC).
Following the release of ENDF/B VIII.1 (2024), Los Alamos National Laboratory (LANL) developed the multi temperature nuclear data libraries Lib81 and ENDF81SaB for applications with MCNP6.3. In parallel, the OpenMC development team produced an ENDF/B VIII.1 based open source nuclear data library compatible with OpenMC. In addition, the JEFF 4.0 release provides neutron induced reaction data in both ENDF 6 and ACE formats over a selected temperature grid. This work presents a comparative assessment of these open source libraries from the perspective of Monte Carlo neutron transport and reactor physics applications.
At CNL, the Lib81 and ENDF81SaB libraries (LANL, 2025) have been ported for use with both MCNP and Serpent, while the ENDF/B VIII.1 based library is employed for OpenMC analyses. These libraries are evaluated with respect to their ability to support modelling of Pressurized Heavy Water Reactors (PHWRs), as well as reactor physics calculations for the zero power ZED 2 reactor at Chalk River and SLOWPOKE research reactors. Selected ZED 2 critical benchmarks are used to illustrate the performance of the Lib81 and ENDF81SaB libraries. Particular attention is given to the simultaneous application of thermal scattering S(α, β) data and DBRC for fuel materials, with a detailed comparison of capabilities and implementation differences among MCNP, Serpent, and OpenMC. The results provide practical guidance for the selection and use of open source multi temperature nuclear data libraries in reactor physics analyses and benchmark studies.
| Session | Processing and Benchmarking |
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