Tellurium behaviour in the Fukushima Dai-ichi Nuclear Power Plant accident

The behaviour of tellurium radionuclides in the Fukushima Dai-ichi Nuclear Power Plant accident was examined to determine if it is consistent with the current understanding of tellurium chemistry, and whether there is any evidence of tellurium dispersal by species other than aerosols (e.g., vapours). Previous speciation studies, hot-cell experiments, in-reactor experiments and the transport from the Chernobyl reactor accident indicated that tellurium would behave primarily as a particulate species that condensed at high temperature, although the initial chemical species may have transformed to other solid species on cooling and reaction with environmental compounds (e.g., air). The main volatile tellurium species expected would be organic tellurides, which could be produced by radiolytic or biochemical routes, and have reasonable stability under environmental conditions. The behaviour of Cs-137, which behaves exclusively as a particulate species in air at environmental temperatures, was compared with that of tellurium. The behaviour of tellurium was found to be consistent with the current understanding and no evidence of significant tellurium transport by vapour species was found.