August 8, 2024
This research aims to identify the best performing materials for the development of a metal film pump for selective separation of deuterium and tritium from a mix of gases. A metal film pump is a critical subsystem needed to enable the direct internal recycling (DIR) of tritium in a fusion power plant. Unlike conventional metal foil pumps, the film pumps General Atomics (GA) develops are at least one hundred times thinner. A film pump is advantageous; it facilitates a faster diffusion of gas and can be grown using established techniques. GA’s fabrication method assures ultra-clean interfaces, which are fundamental to hydrogen absorption, and allows comixing dopants that increase gas permeation selectivity and help mitigate hydrogen embrittlement effects. Idaho National Laboratory is partnering with GA to test deuterium superpermeation properties and monitor material property changes on GA’s film by subjecting it to realistic operational temperature and pressure conditions. For fusion power plants, the DIR concept has the potential to extract unused deuterium and tritium directly from the fuel exhaust of the reactor and direct them back into the gas distribution cycle, bypassing the complex and expensive tritium recovery plant (TRP). If successful, this could ease the burden on the TRP, thus reducing capital cost and onsite tritium inventory by a factor of ~400%, increasing safety, and easing the regulatory requirements. It could also reduce the cost to purchase, produce, and store tritium for future fusion power plants.