Conversion of tritium gas to tritiated water in the environment (literature survey)

The literature on conversion of tritium gas to tritiated water in various environments is reviewed. The conversion mechanisms and the conversion rates are as follows.1. In the oxidation with oxygen and the isotopic exchange with water, tritium β-rays and metal catalyst are effective. The oxidation rate is -0.02%/day at initial tritium concentration ≤10-2Ci/l and -2%/day at 1Ci/l. In the presence of oxygen and water, it is not clear whether the exchange reaction occurs or not because of the small amount of data.2. For biological conversion, soil microorganisms contribute significantly. The conversion rate is greater than 10%/hr. The tritium gas deposition velocity, which includes the uptake rate of tritium gas by soil and the conversion. rate, ranges from 0.0025 to 0.11cm/sec and is influenced by temperature and moisture of the soil.3. Tritium gas is converted to the tritiated water througn the reaction with hydroxyl radical produced by sunlight in the atmosphere.