Utilizing Sensitivity and Correlation Coefficients from MCNP and Whisper to Guide Microreactor Experiment Design

Abstract

When designing experiments for full-scale reactor systems, the Monte Carlo N-Particle® and Whisper codes can be used to create neutronic models and compare the similarity of two nuclear systems via correlation coefficients for $k_{eff}$, the effective multiplication factor. This paper applies this framework to a conceptual heat pipe yttrium-hydride-moderated microreactor system and experiments, but the method can be applied generally to any nuclear reactor design. The framework is intended as a supplement to other neutronics/thermal/multiphysics analyses and provides an objective method to measure the neutronic similarity of two systems. By analyzing the shared nuclear data uncertainty, as well as sensitivity to nuclear data over all neutron energies, highly informative experiments can be designed to aid in the development of microreactor and other advanced reactor technologies and systems.

Keywords:

• Microreactors
• experiment design
• sensitivity/correlation coefficients
• MCNP6/Whisper

Disclosure Statement

No potential conflict of interest was reported by the authors.

Notes

^a MCNP® and Monte Carlo N-Particle® are registered trademarks owned by Triad National Security, LLC, manager and operator of LANL. Any third-party use of such registered marks should be properly attributed to Triad National Security, LLC, including the use of the designation as appropriate.

Additional information

Funding

This research was supported by the Laboratory Directed Research and Development program of LANL under project numbers 20210801ER “Prediction Improvements of Transient Behavior in Advanced Reactors” and 20220084DR “Next Generation Small Nuclear Reactors.” The NCERC facility is supported by the U.S. Department of Energy (DOE) Nuclear Criticality Safety Program, funded and managed by the National Nuclear Security Administration (NNSA) of the DOE. This work was supported by the DOE through LANL. LANL is operated by Triad National Security, LLC, for the NNSA of the DOE (contract no. 89233218CNA000001). This paper is approved for unlimited release under LA-UR-22-28629.