Vacuum Vessel Tritium Removal

Vacuum Vessel Tritium Removal

Pulse Discharge Cleaning (PDC)
Achieved two types of cleaning. First, low-powered plasmas were pulsed out every few seconds, cleaning off impurities on the limiter and the walls. At the same time, this process heated the bumper limiter to 250 degrees centigrade, effectively "degassing" or boiling the gases out of the walls.
Glow Discharge Cleaning (GDC)

Cleaned the internal surfaces of the vacuum vessel by bombarding the inside walls of the vessel with helium atoms to knock off impurities.
Vessel Bakeout (150 degrees centigrade)

Heats the vacuum vessel to 150 degrees centigrade, driving out impurities that have collected on the internal surfaces.
Vessel Air Purge

A continuous air purge of the vacuum vessel was processed to the molecular sieve beds using the Torus Cleanup System (TCS) configured for once through operation.
Drum Bubbler System

The drum bubbler was designed to reduce the Tritium concentration of the vacuum vessel over an extended period of time. The main components of the system are a 55 gallon drum that is approximately two thirds full of water and is connected to the end of the torus pump duct, a dual piston pump connected to the outlet of the drum and a dryer in the exhaust line of the pump. The pump pulls a partial vacuum over the surface of water and draws air from the vacuum vessel through the water in the drum, and tritium oxide is scrubbed out of the air stream. The exhaust is then vented to the stack.