The TFTR Plasma Exhaust Tank System

The Plasma Exhaust Tank (PET) allows TFTR neutral beam regeneration gas to be collected separate from the total TFTR exhaust thereby minimizing the impurities (i.e. oxygen, sulfur hexaflouride). The PET then forwards this gas to the Tritium Purification System (TPS). The PET is capable of holding a minimum of 2 normal neutral beam regenerations (200 std. liters each) with a nitrogen backfill (400 std. liters). Since this volume is slightly less than the volume for 4 neutral beam regenerations without backfill, the tank is sized for the latter case (~980 std. liters). The PET pump provides a feed of 2 liters per minute to the TPS with a pressure range of 750 Torr to 200 Torr. At 2 liters per minute and 200 Torr at the discharge of the PET pump the tank can reach a final pressure of 70 Torr. When the TPS output does not meet the requirements for tritium purity, the PET is capable of receiving inferior grade tritium gas back from the TSDS for reprocessing