Contribution of internal dose to the exposure in the Fukushima exclusion zone

Tschiersch, J.*; Yoshimura, Kazuya  ; Spielmann, V.*; Iijima, Kazuki  ; Shinonaga, Taeko*; Miyahara, Kaname  

Inhalation dose depends on the kind and amount of inhaled radionuclides, but also on the size of radioactive particles and the solubility of the radionuclides in the lungs. In the Fukushima exclusion zone large scale decontamination activities take place which influence amount and size distribution of resuspended material. Initial measurements during such works provide experimental data of the main parameters (including size distribution with activity median aerodynamic diameter (AMAD) and geometric standard deviation). Measured parameters are compared to ICRP default values. Variability is studied and the range of potential inhalation dose assessed.