Investigation into the radiation chemistry of tritiated water

Evolution of overpressure above T2O and the ultraviolet absorbance of the liquid have been monitored with time. Excess T2 overgas was employed in one experiment to reconstitute decayed tritium of T2O and to suppress radiolytic decomposition to T2 and O2 gases. No suppressor-T2 was employed in a second experiment. G-factors for radiolytic gas evolution and for liquid-phase recombination in the second experiment are consistent with previously published values. The equilibrium value of [T2O2] attained there is likewise consistent. These factors suggest similarity between T2O self-β-radiolysis and β- or γ-irradiation of H2O and D2O. Suppression of radiolysis in the first experiment was effective down to 2.8 psia of T2. Below this value, radiolytic pressures increased rapidly, while uv absorbance, having slowly increased before this, first decreased precipitously, then increased once more. The threshold pressure for suppression may be consistent with previous α-irradiated H2O results. Both threshold and uv absorbance behavior, however, may be related to the presence of organics (alcohols or carboxy species) present in solution