Oxidized tritium around a research reactor site

The concentration and distribution of tritium in environmental samples obtained from sites near the Kyoto University Research Reactor were studied. About 5 GBq of tritium is discharged yearly from the KURR stack. The concentrations of tritium in the exhaust air, atmospheric moisture and precipitates were monitored to estimate not only any effects of tritium sources on the concentrations in the nearby environment but also the dilution factor of pollutants at the site boundary. The concentrations of tritium in surface water at the site were also monitored to identify the possibility of pollution in the water system. In both cases, there was slight contamination in samples near the site. The increased annual dose to an adult from tritium discharged in the atmosphere was estimated to be about five orders of magnitude lower than that from natural background radiation. (author)