Radiochemical reactions between tritium and humid air

Radiochemical reactions between pure tritium (T₂) and moist air have been examined using real-time Raman spectroscopy. The reacting constituents were contained in a 1 cm³ quartz cell sealed by a quartz-to-metal seal leading to a valve. A near-stoichiometric mixture of T₂ and O₂ was introduced into the cell, and the time evolution of the composition was monitored at 297 K for twenty-nine days. The production of T₂O was observed in these experiments, for the first time unambiguously detected in Raman spectroscopy. T₂O exhibits a relatively weak vibrational band at ~2241 cm^-1. The radiochemical production of tritiated water did not occur in the expected 2:1 ratio, but rather with the O₂ disappearing totally when the T₂ was only slightly over halfway depleted. After the disappearance of O₂, the T₂ partial pressure continued to decrease, but at a slower rate. The initial water in the moist-air mixture disappeared totally after about 15 hours, with no concomitant production of HT. A small quantity of CO₂ was also detected, presumably produced by radiochemically driven reactions with stainless steel components