Transport phenomena and occupational consequences of a tritium release

Tritium gas, normally in sealed containers, will be present in the US Department of Energy's (DOE's) facilities conducting fusion energy research. A probability of tritium release, however small, exists in these facilities. Once released, tritium can back-diffuse against ventilation flow to contaminate other areas of the facility. Tritium can also be released to the environment by exhaust blowers. The problem of back-diffusion of tritium released in a typical DOE facility was examined as a function of flow rates of the ventilation system. The source term (release to the environment) in the emergency ventilation flow was also calculated. The consequences to personnel in the release room and in an adjacent corridor due to back-diffusion were determined. It was shown that for credible release scenarios, the consequences in the adjacent corridor from tritium back-diffusion were negligible. Higher doses in the release room can be avoided by well-planned emergency evacuation procedures. The source term was calculated, but the on- and off-site consequences were not determined