Evaluation of Internal Exposure of the Workers and the Residents Caused by the Fukushima Nuclear Accident

The accident at the Fukushima Daiichi Nuclear Power Plant has resulted in many cases of internal exposure to radionuclides. JAEA staff has examined the workers and the residents by measurement with a various type of whole body counters. The committed effective dose was estimated using the intake scenarios according to the object of monitoring and expected level of exposure. In the examination of more than 500 workers who were in the plant at early stage of the accident or engaged in disaster-mitigation activities, I, Te-I, Cs and Cs were detected and the maximum committed effective dose estimated based on the most severe scenario was 590 mSv. The monitoring for extended residents begun about 4 months after the accident. In this monitoring project, only Cs and Cs were detected instead of radioiodine.