Treatment of molten fluoride salt-exposed graphite: Cleaning made simple

Y. Huang; G. Zheng; D. J. Sprouster; L. L. Snead

doi:10.1016/j.anucene.2025.111386

Treatment of molten fluoride salt-exposed graphite: Cleaning made simple

Y. Huang
, G. Zheng
, D. J. Sprouster
, L. L. Snead

Materials Science and Engineering

Massachusetts Institute of Technology

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

1 Scopus citations

Abstract

To ensure chemical stability in storage and transportation containers, graphite waste from Fluoride-cooled High-temperature Reactors (FHRs) requires treatment to remove residual fluorides and beryllium before disposal. This study demonstrates a simple, effective cleaning method for modern fine-grained nuclear graphite exposed to molten FLiBe salt under neutron irradiation. A straightforward soaking in deionized water successfully removed near-surface salt, confirmed through cross-sectional scanning electron microscopy, energy-dispersive spectroscopy mapping, and X-ray diffraction. Additional in situ electrochemical monitoring and ex situ fluorometer assays validated this approach. Post-cleaning analyses confirm the process effectively decontaminates graphite surfaces exposed to FLiBe during irradiation, offering a practical solution for FHR graphite waste management.

Original language	English
Article number	111386
Journal	Annals of Nuclear Energy
Volume	218
DOIs	https://doi.org/10.1016/j.anucene.2025.111386
State	Published - Aug 2025

Keywords

FLiBe Salt
Fluoride-cooled Hight Temperature Reactor
Graphite Waste Recycling
Nuclear Graphite

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10.1016/j.anucene.2025.111386

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title = "Treatment of molten fluoride salt-exposed graphite: Cleaning made simple",

abstract = "To ensure chemical stability in storage and transportation containers, graphite waste from Fluoride-cooled High-temperature Reactors (FHRs) requires treatment to remove residual fluorides and beryllium before disposal. This study demonstrates a simple, effective cleaning method for modern fine-grained nuclear graphite exposed to molten FLiBe salt under neutron irradiation. A straightforward soaking in deionized water successfully removed near-surface salt, confirmed through cross-sectional scanning electron microscopy, energy-dispersive spectroscopy mapping, and X-ray diffraction. Additional in situ electrochemical monitoring and ex situ fluorometer assays validated this approach. Post-cleaning analyses confirm the process effectively decontaminates graphite surfaces exposed to FLiBe during irradiation, offering a practical solution for FHR graphite waste management.",

keywords = "FLiBe Salt, Fluoride-cooled Hight Temperature Reactor, Graphite Waste Recycling, Nuclear Graphite",

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year = "2025",

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doi = "10.1016/j.anucene.2025.111386",

language = "English",

volume = "218",

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TY - JOUR

T1 - Treatment of molten fluoride salt-exposed graphite

T2 - Cleaning made simple

AU - Huang, Y.

AU - Zheng, G.

AU - Sprouster, D. J.

AU - Snead, L. L.

PY - 2025/8

Y1 - 2025/8

N2 - To ensure chemical stability in storage and transportation containers, graphite waste from Fluoride-cooled High-temperature Reactors (FHRs) requires treatment to remove residual fluorides and beryllium before disposal. This study demonstrates a simple, effective cleaning method for modern fine-grained nuclear graphite exposed to molten FLiBe salt under neutron irradiation. A straightforward soaking in deionized water successfully removed near-surface salt, confirmed through cross-sectional scanning electron microscopy, energy-dispersive spectroscopy mapping, and X-ray diffraction. Additional in situ electrochemical monitoring and ex situ fluorometer assays validated this approach. Post-cleaning analyses confirm the process effectively decontaminates graphite surfaces exposed to FLiBe during irradiation, offering a practical solution for FHR graphite waste management.

AB - To ensure chemical stability in storage and transportation containers, graphite waste from Fluoride-cooled High-temperature Reactors (FHRs) requires treatment to remove residual fluorides and beryllium before disposal. This study demonstrates a simple, effective cleaning method for modern fine-grained nuclear graphite exposed to molten FLiBe salt under neutron irradiation. A straightforward soaking in deionized water successfully removed near-surface salt, confirmed through cross-sectional scanning electron microscopy, energy-dispersive spectroscopy mapping, and X-ray diffraction. Additional in situ electrochemical monitoring and ex situ fluorometer assays validated this approach. Post-cleaning analyses confirm the process effectively decontaminates graphite surfaces exposed to FLiBe during irradiation, offering a practical solution for FHR graphite waste management.

KW - FLiBe Salt

KW - Fluoride-cooled Hight Temperature Reactor

KW - Graphite Waste Recycling

KW - Nuclear Graphite

UR - https://www.scopus.com/pages/publications/105000963297

U2 - 10.1016/j.anucene.2025.111386

DO - 10.1016/j.anucene.2025.111386

M3 - Article

AN - SCOPUS:105000963297

SN - 0306-4549

VL - 218

JO - Annals of Nuclear Energy

JF - Annals of Nuclear Energy

M1 - 111386

ER -

Treatment of molten fluoride salt-exposed graphite: Cleaning made simple

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Keywords

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