Extended operation of reactor-scale fusion fuel loop under US-Japan collaboration

Tritium Systems Test Assembly (TSTA) in the Los Alamos National Laboratory is a reactor-scale fusion fuel processing loop and is operated by the Japan Atomic Energy Research Institute (JAERI) and the USDOE under the collaboration. An extended experimental campaign of the TSTA loop was performed with 100 grams of tritium in April-May 1992 in order to simulate a steady-state fusion fuel processing for 25 days. Continuous processing of simulated plasma exhaust (DT and H mixture, He, CH₄ and N₂) was successfully demonstrated. Impurity processing was successfully tested by two different techniques. US developed Fuel Cleanup System (FCU) purifies DT by cryogenic molecular sieve beds and decomposes tritiated water by Magnesium beds. Japanese developed J-FCU is based on purification by permeation through palladium alloy membrane and vapor electrolysis with a ceramic electrolyte cell. Isotope Separation System was stably operated with four interlinked columns and continuously produced pure tritium and deuterium stream while exhausting protium impurity. Real-time analysis in the ISS process was demonstrated with the laser Raman Spectroscopy. The result demonstrated the safe and stable operation of reactor-scale fusion fuel loop in a steady state