Development of a High Level Tritium Handling System : Design and Fabrication of Tritium Circulation Subsystem

We designed an experimental system capable of handling at least 100 Ci tritium in an experimental run: the amount is considered to be necessary for a variety of experiments aiming at investigating the physicochemical properties of tritium. As a first step, we fabricated one of its subsystems, tritium circulation subsystem, in order to examine pumping and out gassing characteristics of the subsystem as well as the potential of Zr-based alloys for the storage and recovery of about 1000 Ci of tritium. It has been observed that the combination of a mechanical roughing pump and sorption pump could evacuate the subsystem down to 1x10-6 Torr. It was suggested, however, that the adsorption and desorption of HTO on/from the inner wall of tritium systems would cause serious problems on safety and environmental aspects as well as pumping characteristics, requiring thus the development of surface coating layers to protect the wall from tritium adsorption and/or adsorption