Calculation of the absorbed dose for the overexposed patients at the JCO criticality accident in Tokai-mura.
The doses for the overexposed patients were estimated by the measurement result of specific activity of 24Na in blood. The present method is almost based on documents of the International Atomic Energy Agency (IAEA) and the Oak Ridge National Laboratory. The neutron energy spectrum obtained using the ANISN code (Multigroup One-Dimensional Discrete Ordinates Transport Code System with Anisotropic Scattering) was assumed. The values in ICRP Publication 74 were applied for the doses in each organ per unit neutron fluence. Gamma-ray dose was indirectly estimated based on (a) the result of environmental monitoring around the accident site and (b) a graph in IAEA manual, which gives the kerma ratio of neutrons and gamma-rays as a function of the critical volume or the atomic ratio of hydrogen to 235U. The estimated neutron doses were 5.4 Gy for patient A. 2.9 Gy for patient B and 0.81 Gy for patient C. The estimated gamma-ray doses were 8.5 or 13 Gy for patient A, 4.5 or 6.9 Gy for patient B, and 1.3 or 2.0 Gy for patient C.
Ishigure
N
N
Environmental Radiation Protection Research Group, National Institute of Radiological Sciences, Chiba, Japan. ishigure@nirs.go.jp
Endo
A
A
Yamaguchi
Y
Y
Kawachi
K
K
D005214:Fast Neutrons / Q000009:adverse effects; D005720:Gamma Rays / Q000009:adverse effects; D006801:Humans; D007564:Japan; D009784:Occupational Diseases / Q000097:blood; D016273:Occupational Exposure; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000097:blood; D018788:Radioactive Hazard Release; D012979:Sodium Radioisotopes / Q000097:blood
D012979:Sodium Radioisotopes