A Process to Recover Tritium from High Pressure Helium

A coolant that has gained increased prominence in fusion reactor designs is high-pressure (greater than or equal to 50 atm) helium. One of the major problems to be resolved with this coolant is effective tritium removal and recovery so that environmental losses are minimized but the efficiency of the plant is not compromised. Since the worse case situation is one in which the high-pressure helium coolant is used not only as a coolant but also as the main tritium recovery route, we directed our attention to designing a tritium recovery system that could handle this worst case, as well as simpler cases. The design that evolved was a system in which a liquid getter (sodium is our example case) is used to strip all tritium, deuterium, and oxygen species from the high-pressure helium. The hydrogen species are removed from the sodium either by using a cold trap or by contacting the sodium with a molten salt. The tritium can be recovered from the molten salt by electrolysis. Impurities, including oxygen, are removed from the sodium through the use of a cold trap on a small fraction (less than or equal to 10%) of the total sodium flow.