Room-temperature reactor packed with hydrophobic catalysts for the oxidation of hydrogen isotopes released in a nuclear facility

Iwai, Yasunori; Sato, Katsumi; Taniuchi, Junichi*; Noguchi, Hiroshi*; Kubo, Hitoshi*; Harada, Nobuo*; Oshima, Yusuke*; Yamanishi, Toshihiko

The inorganic-based hydrophobic Pt-catalyst named H1P has been developed especially for efficient oxidation of a tracer level of tritium in the ambient temperature range even in the presence of saturated water vapor. The overall reaction rate constant for H1P catalyst in the ambient temperature range was considerably larger than that for traditionally applied Pt/AlO catalyst. Moreover, the decrease in reaction rate for H1P in the presence of saturated water vapor compared with in the absence of water vapor was slight due to its excellence in hydrophobic performance. Oxidation reaction on the catalyst surface is the rate-controlling step in the ambient temperature range and diffusion in a catalyst substratum above 313 K due to its fine porosity. The overall reaction rate constant in the ambient temperature range was dependent on the space velocity and hydrogen concentration in carrier.