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 137Cs, 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.

Radioiodine in the atmosphere after the Fukushima Dai-ichi nuclear accident.

About 160 PBq of (131)I was released into the atmosphere during the accident at the Fukushima Dai-ichi Nuclear Power Plant. The chemistry of radioiodine is complicated, and it can be released in several different forms. In addition, the different physical forms, like molecular iodine, aerosol-form iodine, or organic iodine, would have all behaved differently once in the atmosphere, and would have been removed at different rates. These releases were detected by monitoring stations throughout Japan, and from these measurements, key insights can be made about the different chemical forms that were released, as well as the persistence of each in the environment.