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The Tokamak Fusion Test Reactor (TFTR) was supplied over 7.5/spl times/10/sup 5/ Curies combined through the vacuum vessel and Neutral Beam (NB) tritium gas injectors. Out of this quantity approximately 29,530 Curies (Ci) has entered the vacuum vessel as neutral atoms, including cold streaming gas and 20,270 Ci as direct vessel injection. TFTR has had two short term outages during DT operations Outage 1('95) and 2('96), plus the final shutdown, Outage 3 ('97), after DT operations in which tritium held up in the vessel and NB's has been actively recovered. The respective recovery values are: Outage (No.1) 8,257 Ci, (No.2) 4,668 Ci and (No.3 final shutdown) 3965 Ci. The methods for recovering this included: 1. Vessel baking to 150/spl deg/C during Deuterium Glow Discharge Cleaning (DGDC), 2. Helium/Oxygen GDC (HeOGDC), 3. Pulse Discharge Cleaning (PDC), 4. Continuous moist air purges and 5. Dry air, moist air (40% RH), and deuterium vent/soak/pump. The processes showing equivalent efficiency are the GDC, HeOGDC, and moist air purges at elevated temperatures. A small amount of tritium is introduced in the vessel at high energy through the NE /spl sim/3% relative to that supplied to the beam lines and /spl sim/1/2 of this is essentially buried in the carbon composite tiles and has a longer time constant for removal than the direct vessel injected tritium. Data shows that the bulk of surface tritium is removed by active cleaning methods and in the presence of moist air purges (room air at /spl sim/40% relative humidity) combined with elevated temperatures which accelerates its removal. Continuous outgassing at low levels in the presence of moist air (750 Torr) follows the active tritium removal processes and moist air purges. The TFTR tritium removal processes and their corresponding removal rates and quantities are reported. An ion chamber is used to measure the tritium accumulated in the Gas Holding Tanks (GHT) from the vessel throughout all the active and passive processes. The ion chamber compensation for varying gas mixtures was found to be critical in accurate measurement of this recovery and is discussed.

Several ion sources failed during the last months of TFTR operation. Four suffered are chamber vacuum leaks which admitted SF/sub 6/ into the source. One of these also had warped accelerator rails which resulted in damage to a water cooled scraper. The arc chamber leaks occurred at the boundary between the probe plate and either the bucket or interface plate. Vacuum seals at those locations consist of a mylar insulator sandwiched between two o-rings. At the failure point, the mylar had been punctured back to the o-ring. Are tracks were observed along the plasma facing surfaces of the probe plate and were funneled into every other gap between magnet. This evidence is suggestive of J/spl times/B forces driving the arcs toward the interface between the various plates and toward the o-ring. Damage is correlated with high arc power and the failure to expeditiously extinguish the arc. Operation with additional anode area is suggested as a means to avoid are creation. On the source with the warped grid rails, a section of a nearby scraper was melted. TFTR ion sources are masked down versions of the US Common Long Pulse Ion Source. Four rails on either end of the source are masked creating an ion beam that is /spl sim/43 cm tall. Rails under the mask were the most deformed (0.055" out of tolerance). Damage is believed to have occurred during 3 s pulses when 15 MJ were extracted over 3 s under slightly overdense conditions. The rails were deflected back towards the arc chamber causing the edge beamlets to be directed away from the axis.

750,000 Ci of tritium have passed through the TFTR neutral beamlines since December, 1993. During the course of 725 tritium heated discharges, 47,000 Ci have been extracted as ions from the ion sources and 27,000 Ci injected into TFTR as neutral atoms. Prior to the commencement of deuterium-tritium (DT) experiments, Los Alamos and Sandia National Laboratories made estimates of tritium retention in each beamline due to implantation in the 2 m/sup 2/ of copper beam absorbers and absorption on the 250 m/sup 2/ of internal surface area. Their estimates were: 500 Ci embedded per beamline in beam absorbers after 1000 DT Shots; and 100 Ci adsorbed per beamline after exposure to 1 torr of tritium for 1 hour. Both estimates were revised downward since the estimates assumed pure tritium operation, whereas the neutral beams used orders of magnitude more deuterium than tritium. Deuterium competes with tritium for implantation and adsorption sites, reducing the uptake of tritium relative to the use of pure tritium. Data from neutron detectors indicated that the quantity of tritium implanted is equivalent to the revised estimate. The amount of adsorbed tritium exceeds the prediction. While tritium operation was highly successful, there were problems with the failure of several ion sources and gas injectors. Ion source failures were not due to the use of tritium as the working gas. However, their removal yielded information regarding tritium retention. Ten tritium injectors failed during the three and a half years of tritium experiments; six were replaced. At the conclusion of TFTR operation, all working tritium injectors had throughput leaks. By comparison, the deuterium injectors, which used the same valves, had only two minor fill valve leaks, and no repairs were necessary. Tritium contaminated component removal required purging until the concentration of tritium in any released air was