Self-Decomposition Behavior of High Concentration Tritiated Water

In order to handle high-level tritiated water (HTO) safely, the self-decomposition behavior has been investigated as functions of tritium concentration (from 16 GBq/cm 3 to 2 TBq/cm 3 ) and storage temperature (269K ∼ 303K). The representative decomposition products such as H 2 in the gas phase and H 2 O 2 in the liquid phase were measured periodically, storing HTO in a leak-tight vessel. The effective production rate of H 2 increased with tritium concentration, however, the normalized production rate by tritium decay, like effective G-value, decreased with tritium concentration. The effective production rate of H 2 O 2 also increased with tritium concentration and the normalized one also decreased under consideration of its natural decomposition rate, though it thought that the almost H 2 O 2 calculated by the reported G-value decomposed by extra stimulus in tritiated water. The effective production rates of H 2 and H 2 O 2 increased with temperature.