SRNL has developed and patented methodology for lithium hydride electrolysis which can be extended for the extraction of hydrogen isotopes from molten lithium and Pb-Li blankets. This process utilizes a ceramic lithium ion conductor that can be directly immersed in blanket buffer tank to facilitate the electrochemical extraction of hydrogen isotopes from the molten blanket material. The extraction of hydrogen isotopes from lithium is necessary for the safe and reliable operation of fusion reactors that utilize molten metals as a tritium breeding blanket in the system. A number of technologies for hydrogen isotope extraction from molten lithium and Pb-Li blankets have been proposed that can facilitate the extraction of hydrogen isotopes. However, some like the Maroni process require a series of complicated mechanical steps (expensive mechanical parts with limited lifetimes) in order to carry out the separation and prevent impurities build up in the extraction process. The electrochemical process can potentially simplify the isotope extraction process by eliminating many of the mechanical parts and being able to integrate this technology within the fusion reactor to perform the extraction in-line. A Lithium Lanthanum Zirconate (LLZO) immersion electrode that is inserted in the Li/LiT mixture has been designed and tested for the reaction and has shown the ability to be able to electrolyze LiD. The extraction of hydrogen and deuterium from molten lithium was verified during this experiment and indicates this new process is a potential alternative for other processes used for the extraction of hydrogen isotopes. Process modeling is also performed to understand the mass balance, energy requirements, and electrode areas needed for decomposing different concentrations of tritium. Doped LLZO electrolytes have been developed that have high lithium ion conductivity and are stable when exposed to molten lithium.

Electrochemical extraction of hydrogen isotopes from Li/LiT mixtures

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.