Design and Performance of High-Temperature Furnace and Cell Holder for In Situ Spectroscopic, Electrochemical, and Radiolytic Investigations of Molten Salts
December 1, 2020
The Science
Understanding molten salt chemistry in nuclear systems requires experimental tools capable of operating under high temperature and radiation while directly probing chemical reactions in real time. Researchers developed a suite of specialized experimental platforms that combine spectroscopy, electrochemistry, and radiation-based measurements for in situ studies of molten salts. These systems enable direct observation of oxidation-state changes, reaction kinetics, and radiation-induced chemistry in environments relevant to molten salt reactors. The work establishes an integrated experimental framework for studying coupled chemical and radiolytic processes under realistic operating conditions.
The Impact
Experimental limitations have long restricted the ability to study molten salt chemistry during high-temperature operation and irradiation. This work provides a versatile tool for directly measuring redox behavior and reaction kinetics, and for detecting transient species, in situ. These capabilities improve the ability to investigate corrosion, radiation chemistry, and electrochemical processes in molten salt systems relevant to advanced energy technologies.
Summary
This study reports the development of three complementary experimental systems for in situ investigation of molten salts under extreme conditions.
The first platform integrates optical spectroscopy and electrochemistry within a high-temperature furnace, enabling simultaneous monitoring of redox reactions and spectroscopic changes in molten salts. A second system supports pulse radiolysis measurements, allowing time-resolved observation of short-lived radiation-induced species and their reaction kinetics. A third compact furnace enables steady-state irradiation experiments coupled with optical spectroscopy.
Initial experiments demonstrated the ability to track oxidation-state changes and radiation-driven chemistry in molten chloride salts. Spectroscopic and electrochemical measurements monitored chromium redox transformations, while pulse radiolysis experiments captured the behavior of solvated electrons and reactive intermediates under high-temperature conditions.
These systems address key challenges associated with molten salt experiments, including high operating temperatures, corrosivity toward containment materials, and sensitivity to moisture and other contamination. By combining multiple analytical techniques in a controlled environment, the platforms enable direct correlation of speciation, chemistry, and dynamics.
Overall, the work establishes a versatile experimental framework for probing molten salt chemistry under realistic operating conditions, supporting mechanistic studies of corrosion, redox processes, and radiation effects.
Contact
Ruchi Gakhar, Idaho National Laboratory, ruchi.gakhar@inl.gov
James F. Wishart, Brookhaven National Laboratory, wishart@bnl.gov
Funding
This work was supported by the Molten Salts in Extreme Environments Energy Frontier Research Center, funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences.
Citation
Phillips, W. C., R. Gakhar, G. P. Horne, B. Layne, K. Iwamatsu, A. Ramos-Ballesteros, M. R. Shaltry, J. A. LaVerne, S. M. Pimblott, and J. F. Wishart. “Design and Performance of High-Temperature Furnace and Cell Holder for In Situ Spectroscopic, Electrochemical, and Radiolytic Investigations of Molten Salts.” Review of Scientific Instruments 91, 083105 (2020). https://doi.org/10.1063/1.5140463
2020-23152 | INT/EXT | Newsroom
