Computational model development and validation of fuel dispersal phenomena

Journal Article · 03 August 2023 · Nuclear Engineering and Design

DOI: https://doi.org/10.1016/j.nucengdes.2023.112516 · OSTI ID:1999992

Moharana, Avinash ^[1]; Shi, Shanbin ^[1]; Howard, Trevor ^[2]; Marcum, Wade  ^[2]; Spencer, Benjamin W.  ^[3]

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1. Rensselaer Polytechnic Institute, Troy, NY (United States)
2. Oregon State University, Corvallis, OR (United States)
3. Idaho National Laboratory (INL), Idaho Falls, ID (United States)

As the US nuclear industry is renewing efforts to extend the rod average burnup limits in existing pressurized water reactors, it becomes imperative to investigate the safety implications associated with high burnup fuel fragmentation and the potential dispersal of fragmented fuel into the reactor coolant system. Additionally, as there is a growing interest in transitioning to new nuclear fuel designs to accommodate higher fuel burnup levels, it becomes essential to conduct studies on fuel behavior during design basis accident scenarios, particularly during a postulated loss-of-coolant accident, in order to ensure the safe operation of light-water reactors. The present study develops a computational model to simulate the complex three-phase flow of the fuel dispersal phenomena that occur following a breach in the cladding, when the stream of solid fuel particles and carrier fission gas stream may interact with the surrounding liquid medium. Furthermore, the proposed framework considers the solid phase as discrete Lagrangian particles while the interpenetrating gas–liquid continuum is modeled using a Eulerian framework. The developed simulation framework is validated with experimental results performed in a separate-effect test facility by comparing predicted particle settlement locations with the experimental observations reported in the literature. Key highlights of this study include the interpretation of the high-pressure boundary conditions and the three-phase flow coupling strategy. Also discussed are the gas–liquid hydrodynamics and the behavior of particles as they are transported through the gas and liquid phases.

• Research Organization: Idaho National Laboratory (INL), Idaho Falls, ID (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE); USDOE Office of Nuclear Energy (NE), Nuclear Energy University Program (NEUP)
• Grant/Contract Number: AC07-05ID14517
• OSTI ID: 1999992
• Report Number(s): INL/JOU--23-71924-Rev000
• Journal Information: Nuclear Engineering and Design, Journal Name: Nuclear Engineering and Design Vol. 413; ISSN 0029-5493
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English