LAUSR

Abstract A method combined oxidation catalytic reactor and water bubbler is the most quantitative analysis method for gaseous tritium. We developed a tritium measurement system with high accuracy using an organic-based hydrophobic platinum catalyst previously. However, the previous measurement system had a shortcoming that the catalyst was combustible over 100 °C. To overcome the shortcoming, we developed an inorganic-based hydrophobic platinum catalyst (Pt/SiO 2 ) which was noncombustible. The developed Pt/SiO 2 catalyst was specially enhanced the hydrophobicity to prevent adsorption of water vapor on the surface of catalyst. To oxidize tritium efficiently, the particle diameter of 1mmϕ was selected for the catalyst and hydrogen was intentionally added at the inlet of the catalytic reactor to be the optimal concentration for oxidation. The performance tests showed that a modified quantitative tritium analysis system using by the hydrophobic Pt/SiO 2 catalyst provides tritium measurement with high accuracy more than 99.9%. We have confirmed the modified quantitative tritium analysis system is available in various conditions.