Activity median aerodynamic diameter relating to contamination at Plutonium Fuel Research Facility in Oarai Research and Development Center; Particle size analysis for plutonium particles using imaging plate

Takasaki, Koji; Yasumune, Takashi; Hashimoto, Makoto; Maeda, Koji; Kato, Masato; Yoshizawa, Michio; Momose, Takumaro

JAEA-Review 2019-003, 48 Pages, 2019/03

JAEA-Review-2019-003.pdf:3.81MB

June 6, 2017, at Plutonium Fuel Research Facility in Oarai Research and Development Center of JAEA, when five workers were inspecting storage containers containing plutonium and uranium, resin bags in a storage container ruptured, and radioactive dust spread. Though they were wearing a half face mask respirator, they inhaled radioactive materials. In the evaluation of the internal exposure dose, the aerodynamic radioactive median diameter (AMAD) is an important parameter. We measured 14 smear samples and a dust filter paper with imaging plates, and estimated the AMAD by image analysis. As a result of estimating the AMAD, from the 14 smear samples, the AMADs are 4.3 to 11 m or more in the case of nitrate plutonium, and the AMADs are 5.6 to 14 m or more in the case of the oxidized plutonium. Also, from the dust filter paper, the AMAD is 3.0 m or more in the case of nitrate plutonium, and the AMAD is 3.9 m or more in the case of the oxidized plutonium.

Potential inhalation dose due to remediation activities in the Fukushima exclusion zone

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

no journal, , 

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. Initial measurements during decontamination provide experimental data of the main parameters. These are particle size distribution with activity median aerodynamic diameter (AMAD) and geometric standard deviation and the solubility in the lungs. The dose assessment is performed according ICRP lung model using the computer code IMBA professional. Doses determined from measured parameters are compared to those using ICRP default values. Variability is studied and the range of potential inhalation dose is assessed.