Tritiated Water on Molecular Sieve Without Hydrogen Production

Several molecular sieve beds loaded with tritiated water failed to generate hydrogen gas from tritium self-radiolysis at the expected rate. Preliminary gamma-ray irradiation experiments of 4A molecular sieve with varying amounts of oxygen in the over-gas evoke a quenching mechanism. The data suggest that the gas phase rate constant for the production of hydrogen gas is several orders of magnitude smaller than the third order rate constant for scavenging of radical fragments by oxygen. For the production of hydrogen gas, the rate constant is calculated to be k_rx = (19.6 ±4.5) sec⁻¹ under oxygen scavenging conditions.