Conversion of tritium gas to tritiated water at low tritium concentration

The conversion reaction of tritium gas (T2) to tritiated water was studied experimentally at initial tritium concentrations between 2.6 x 10-4 and 1.3 Ci/m3 in air. Effects of water vapor and catalysts on the conversion reaction were also examined. The potential catalysts, stainless steel, copper, paint and platinum black were used. It was found that first-order rate constants for the reaction in air are independent of initial tritium concentration, and that there is no effect of water vapor on the reaction. The conversion was insensitive to the presence or absence of stainless steel and copper. Paint, which did not influence the rate constant, sorbed T2 and HTO, but the latter was desorbed from the paint by heating. Platinum black produced a remarkable increase of the rate constant. (author)