Characterization of the molten salt FMgNaK through ab initio molecular dynamics and experimental density measurements

Journal Article · 05 September 2021 · Journal of Nuclear Materials

DOI: https://doi.org/10.1016/j.jnucmat.2021.153248 · OSTI ID:1977371

Solano, Andrew R. ^[1]; Clark, Austin ^[2]; Detrick, Kent P. ^[2]; Memmott, Matthew J. ^[2]; Nickerson, Stella D. ^[2]

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1. Brigham Young Univ., Provo, UT (United States); OSTI
2. Brigham Young Univ., Provo, UT (United States)

The selection of a salt species for use in a molten salt reactor MSR is a key part of any MSR design. However, many salts have sparse or no thermophysical property data sets, especially those with higher melting points. One such salt is the eutectic mixture of (NaF)0.345(KF)0.59(MgF₂)0.065, or FMgNaK, and is explored here through ab initio molecular dynamics (AIMD) simulation (1023-1273K) as well as experimental measurement of the liquid density using the Archimedean method (973-1223K). Predicted densities from AIMD are similar to experimentally-measured densities, though with more noise, suggesting that the small scale necessitated by AIMD simulations may be problematic for simulating FMgNaK in particular. Here the coefficient of thermal expansion is predicted from simulation, and salt structure is characterized. Mg-F-Mg chaining is observed in the salt network, though the low concentration of Mg inhibits chaining on the scale that is observed in (LiF)_0.67(BeF₂)_0.33, or FLiBe.

• Research Organization: Brigham Young Univ., Provo, UT (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE); USDOE Office of Nuclear Energy (NE), Nuclear Energy University Program (NEUP)
• Grant/Contract Number: NE0008870
• OSTI ID: 1977371
• Journal Information: Journal of Nuclear Materials, Journal Name: Journal of Nuclear Materials Journal Issue: C Vol. 557; ISSN 0022-3115
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English