A Tritium-Compatible Piezoelectric Valve for the Tokamak Fusion Test Reactor

A commercial peizoelectric valve has been modified to enhance its tritium compatibility, enabling it to provide about 125 tritium gas injections planned for Princeton's Tokamak Fusion Test Reactor (TFTR). The valve was modified at Los Alamos National Laboratory (LAND, exposed to progressively higher concentrations to tritium gas, and repeatedly tested for performance with tritium. The modified valve meets the basic TFTR flow requirements (50 torr L/s), and it survived 3400 torr hr exposure to tritium with neither decrease in performance nor significant leakage across the closed valve. A totally tritium-compatible piezo valve, containing no organic materials, is also proposed and described.This work is supported by the US Department of Energy, Office of Fusion Energy.