CFD simulations of Molten Salt Fast Reactor core cavity flows

Journal Article · 15 May 2024 · Nuclear Engineering and Design

DOI: https://doi.org/10.1016/j.nucengdes.2024.113294 · OSTI ID:2447993

Fang, Jun  ^[1]; Tano, Mauricio ^[2]; Saini, Nadish ^[1]; Tomboulides, Ananias ^[3]; Coppo-Leite, Victor ^[4]; Merzari, Elia ^[4]; Feng, Bo ^[1]; Shaver, Dillon ^[1]

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1. Argonne National Laboratory (ANL), Argonne, IL (United States)
2. Idaho National Laboratory (INL), Idaho Falls, ID (United States)
3. Aristotle University of Thessaloniki (Greece)
4. Pennsylvania State University, State College, PA (United States)

Computational Fluid Dynamics (CFD) has become increasingly important in the research and development of advanced nuclear reactors. Here, in the current study, extensive CFD simulations were conducted for the coolant flow in Molten Salt Fast Reactor (MSFR) core models using the state-of-the-art spectral element flow solver Nek5000 and multiscale coarse-mesh thermal-hydraulic software Pronghorn. The underlying motivation is to seek an in-depth understanding of how the internal velocity distribution can be influenced by the MSFR core cavity shape, the Reynolds number, turbulence modeling options and the inlet boundary conditions. The CFD techniques involved in this investigation range from coarse-mesh CFD, RANS modeling, to the high-fidelity LES calculations. Specifically, a series of RANS simulations were performed for the 2-D axisymmetric core model and 3-D wedge domains to study the flow distribution inside the MSFR core. It is observed that a proper representation of the MSFR inlet channel duct is important for the prediction of internal flow distribution. It is also showcased here how researchers can leverage the Nek5000 CFD results to calibrate more efficient coarse-mesh CFD tools, like Pronghorn, for the actual MSFR design needs. Moreover, this paper highlights a 3-D LES model for an entire MSFR core using the spectral element method and demonstrates the feasibility of this modeling approach. The readiness and potential limitations of the RANS approach are examined with respect to the high-fidelity LES simulations. The present investigation lays a solid foundation as we are leveraging the high-fidelity CFD capabilities to inform MSFR design efforts.

• Research Organization: Idaho National Laboratory (INL), Idaho Falls, ID (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE), Nuclear Energy Advanced Modeling and Simulation (NEAMS)
• Grant/Contract Number: AC07-05ID14517; AC02-06CH11357
• OSTI ID: 2447993
• Report Number(s): INL/JOU--24-79369-Rev000
• Journal Information: Nuclear Engineering and Design, Journal Name: Nuclear Engineering and Design Vol. 424; ISSN 0029-5493
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English