Catalytic oxidation efficiencies for tritium and tritiated methane in a mature, industrial-scale decontamination system

Almost all tritium decontamination systems proposed for fusion facilities employ catalytic oxidation to water, followed by drying, to remove tritium and tritiated hydrocarbons from gas streams. One such large-scale system, the gas purification system (GPS), has been operating in the Tritium Research Laboratory (TRL) at Sandia National Laboratories, Livermore, CA, since October 1977. A series of experiments have recently been conducted there to assess the current operating characteristics of the GPS catalyst. The experiments used tritium and tritiated methane and covered a range of temperatures, flow rates, and concentration levels. When contrasted with 1977 data, the results indicate that no measurable degradation of catalyst function had occurred. However, some reduction in active metal surface area, as indicated by B.E.T. surface area measurements (approx. 100 → 90 m2/g) and AES scans (approx. 1.4 → 0.9 at% Pt), had occurred. Kinetic rate coefficients were also derived and a rough temperature dependence obtained