The structure of molten F7LiNaK with CeF3 using neutron diffraction and EPSR

G. S. Rakib; Jörg C. Neuefeind; Susan Michelle Everett; Rebecca A. Mills; Melissa A. Rose; Shao Chun Lee; Y. Z; Brent J. Heuser

doi:10.1016/j.jnucmat.2025.156000

The structure of molten F⁷LiNaK with CeF₃ using neutron diffraction and EPSR

G. S. Rakib
, Jörg C. Neuefeind
, Susan Michelle Everett
, Rebecca A. Mills
, Melissa A. Rose
, Shao Chun Lee
, Y. Z
, Brent J. Heuser

Research output: Contribution to journal › Article › peer-review

Abstract

The local structure of eutectic F⁷LiNaK (Li-7 enriched, 0.465 ⁷LiF-0.115NaF-0.42KF) which has potential cooling applications in molten salt reactors (MSR), is studied using neutron diffraction. The nearest neighbor distances and the coordination numbers of constituent ion pairs are derived from the total neutron scattering data using empirical potential structure refinement (EPSR) software. A combination of Lennard-Jones and Coulomb 12-6-1 potential (without empirical adjustments) is used that captures the local structure of F⁷LiNaK from simulated 3D atomic configurations. The effect of adding the actinide surrogate cerium on the F⁷LiNaK local structure is also studied using neutron diffraction and EPSR with the same potential model. By comparing the results with previous experimental and computational findings, the effectiveness of EPSR in analyzing complex molten salt structures is demonstrated. The use of EPSR with simple potential models to describe the physical structures of molten salts can offer a computationally efficient approach, reducing both cost and time.

Original language	English
Article number	156000
Journal	Journal of Nuclear Materials
Volume	615
DOIs	https://doi.org/10.1016/j.jnucmat.2025.156000
State	Published - Sep 2025

Funding

This work is supported by the U.S. Department of Energy, Office of Nuclear Energy's Nuclear Energy University Programs, under Award Number DE-NE-0008884. A portion of this research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. Another portion of this research used resources of Chemical & Fuel Cycle Technologies Division at Argonne National Laboratory and was supported by the U.S. Department of Energy, Office of Nuclear Energy, under Contract DE-AC02-06CH11357. This work is supported by the U.S. Department of Energy, Office of Nuclear Energy’s Nuclear Energy University Programs , under Award Number DE-NE-0008884 . A portion of this research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. Another portion of this research used resources of Chemical & Fuel Cycle Technologies Division at Argonne National Laboratory and was supported by the U.S. Department of Energy, Office of Nuclear Energy , under Contract DE- AC02-06CH11357 .

Keywords

Cerium
EPSR
FLiNaK
Local structure
Molten salt
Neutron diffraction

Access to Document

10.1016/j.jnucmat.2025.156000

Cite this

@article{7fdb9429d88a49b1bba09e97fc75085e,

title = "The structure of molten F7LiNaK with CeF3 using neutron diffraction and EPSR",

abstract = "The local structure of eutectic F7LiNaK (Li-7 enriched, 0.465 7LiF-0.115NaF-0.42KF) which has potential cooling applications in molten salt reactors (MSR), is studied using neutron diffraction. The nearest neighbor distances and the coordination numbers of constituent ion pairs are derived from the total neutron scattering data using empirical potential structure refinement (EPSR) software. A combination of Lennard-Jones and Coulomb 12-6-1 potential (without empirical adjustments) is used that captures the local structure of F7LiNaK from simulated 3D atomic configurations. The effect of adding the actinide surrogate cerium on the F7LiNaK local structure is also studied using neutron diffraction and EPSR with the same potential model. By comparing the results with previous experimental and computational findings, the effectiveness of EPSR in analyzing complex molten salt structures is demonstrated. The use of EPSR with simple potential models to describe the physical structures of molten salts can offer a computationally efficient approach, reducing both cost and time.",

keywords = "Cerium, EPSR, FLiNaK, Local structure, Molten salt, Neutron diffraction",

author = "Rakib, \{G. S.\} and Neuefeind, \{J{\"o}rg C.\} and Everett, \{Susan Michelle\} and Mills, \{Rebecca A.\} and Rose, \{Melissa A.\} and Lee, \{Shao Chun\} and Y. Z and Heuser, \{Brent J.\}",

note = "Publisher Copyright: {\textcopyright} 2025 The Author(s)",

year = "2025",

month = sep,

doi = "10.1016/j.jnucmat.2025.156000",

language = "English",

volume = "615",

journal = "Journal of Nuclear Materials",

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T1 - The structure of molten F7LiNaK with CeF3 using neutron diffraction and EPSR

AU - Rakib, G. S.

AU - Neuefeind, Jörg C.

AU - Everett, Susan Michelle

AU - Mills, Rebecca A.

AU - Rose, Melissa A.

AU - Lee, Shao Chun

AU - Z, Y.

AU - Heuser, Brent J.

PY - 2025/9

Y1 - 2025/9

N2 - The local structure of eutectic F7LiNaK (Li-7 enriched, 0.465 7LiF-0.115NaF-0.42KF) which has potential cooling applications in molten salt reactors (MSR), is studied using neutron diffraction. The nearest neighbor distances and the coordination numbers of constituent ion pairs are derived from the total neutron scattering data using empirical potential structure refinement (EPSR) software. A combination of Lennard-Jones and Coulomb 12-6-1 potential (without empirical adjustments) is used that captures the local structure of F7LiNaK from simulated 3D atomic configurations. The effect of adding the actinide surrogate cerium on the F7LiNaK local structure is also studied using neutron diffraction and EPSR with the same potential model. By comparing the results with previous experimental and computational findings, the effectiveness of EPSR in analyzing complex molten salt structures is demonstrated. The use of EPSR with simple potential models to describe the physical structures of molten salts can offer a computationally efficient approach, reducing both cost and time.

AB - The local structure of eutectic F7LiNaK (Li-7 enriched, 0.465 7LiF-0.115NaF-0.42KF) which has potential cooling applications in molten salt reactors (MSR), is studied using neutron diffraction. The nearest neighbor distances and the coordination numbers of constituent ion pairs are derived from the total neutron scattering data using empirical potential structure refinement (EPSR) software. A combination of Lennard-Jones and Coulomb 12-6-1 potential (without empirical adjustments) is used that captures the local structure of F7LiNaK from simulated 3D atomic configurations. The effect of adding the actinide surrogate cerium on the F7LiNaK local structure is also studied using neutron diffraction and EPSR with the same potential model. By comparing the results with previous experimental and computational findings, the effectiveness of EPSR in analyzing complex molten salt structures is demonstrated. The use of EPSR with simple potential models to describe the physical structures of molten salts can offer a computationally efficient approach, reducing both cost and time.

KW - Cerium

KW - EPSR

KW - FLiNaK

KW - Local structure

KW - Molten salt

KW - Neutron diffraction

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