Ultra-High Tritium Decontamination of Simulated Fusion Fuel Exhaust Using a 2-Stage Palladium Membrane Reactor

A 2-stage cold (non-tritium) PMR system was tested with the ITER mix* in 61 days of continuous operation. No decrease in performance was observed over the duration of the test. Decontamination factor (DF) was found to increase with decreasing inlet rate. Decontamination factors in excess of 1.4×10⁵ were obtained, but the exact value of the highest DF could not be determined because of analysis limitations.

Results of the 61-day test were used to design a 2-stage PMR system for use in tritium testing. The PMR system was scaled up by a factor of 6 and built into a glovebox in the Tritium Systems Test Assembly (TSTA) of the Los Alamos National Laboratory. This system is approximately 1/5^th of the expected full ITER scale. The ITER mix was injected into the PMR system for 31 hours, during which 4.5 g of tritium were processed. The 1^st stage had DF =200 and the 2^nd stage had DF=2.9×10⁶. The overall DF=5.8×10⁸, which is greater than ITER requirements.