Estimation of dose from the measurement results of airborne radionuclide concentrations following the Fukushima Dai-ichi Nuclear Power Plant accident; For the public around Tokai-mura, Ibaraki

Takeyasu, Masanori ; Sumiya, Shuichi ; Furuta, Sadaaki

On the basis of airborne concentrations of radionuclides in the Nuclear Fuel Cycle Engineering Laboratories, JAEA, the committed effective dose to adult and committed equivalent dose to thyroid of infant by inhalation were estimated by setting the realistic parameters for indoor-outdoor air concentration ratio, inhalation rate and dose coefficient, and the margin of safety in projected dose was examined. As the results, the estimated doses were about 1/7 for the projected committed effective dose to adult and about 1/10 for the projected committed equivalent dose to thyroid of infant, respectively. These facts indicated that the projected dose had the degrees of safety margin of the factor of 7 for committed effective dose to adult and the factor of 10 for committed equivalent dose to thyroid of infant, respectively. It was the most important parameter for estimating the committed dose that the indoor-outdoor air concentration ratio.