Speaker:  Prof. Ryugo Hayano

University of Tokyo 

 Fukushima Accident, Six (+0.5) years on - How an antimatter physicist reacted to the Fukushima Accident



I will first discuss briefly why an "antimatter physicist" started to work actively in Fukushima. I will then focus on the present situation in Fukushima from the radiological protection view point, and discuss what are the lessons we have learned in these six years.

The Fukushima Daiichi accident contaminated the soil of densely-populated regions of Fukushima Prefecture with radioactive cesium, which poses risks of internal and external exposures to the residents.

Our extensive surveys however showed that the internal exposure levels of Fukushima residents are negligibly low. Nevertheless, families with small children are still much concerned about internal exposures. We therefore developed a whole body counter for small children, called the 'BABYSCAN', with which we have scanned more than 10,000 babies, and have shown that Fukushima babies are free of radiocesium.

As for the external exposure, we launched a project to compare personal doses of high-school students living in Fukushima, outside of Fukushima, France, Poland and Belarus. This study, participated by more than 200 students and teachers, has clearly shown that the external doses in Fukushima are well within the range of natural background.

These are good news, but the fact remains that nearly 50,000 people are still unable to return even though the radiation level in most areas have become low enough. The problems in Fukushima, after six years, are mostly psychosocial, rather than radiation risks.