Cooperation process between a local government and experts in official voluntary decontamination of environmental radioactivity

Kashiwa city, inside the Tokyo metropolitan area and located ~200 km south of the Fukushima Dai-ichi Nuclear Power Plant, received a raised environmental ambient radiation dose due to the disaster relative to the rest of area. In this paper, the challenging process of the official voluntary decontamination activity in Kashiwa city, Chiba prefecture, which was carried out with strong cooperation between a local government and experts, is described and reviewed in terms of the effectiveness of the radiation protection. The support system for the official voluntary decontamination work was constructed by the citizens. It was completed within ~15 months after the accident, by way of the following five main steps. (i) A local forum was organized, commencing an open discussion. (ii) (a) Some civic groups started their own activities independent of the national and local governments' policies and measures, and (b) Kashiwa city office held information symposia and risk communication meetings with key persons as a kind of stakeholders as well as education and training of official leaders for voluntary decontamination work. (iii) Joint positive discussion and work projects between civic groups and the local government were started by key personnel. (iv) Local government planned and fixed its official decontamination strategy based on the results of several open discussions. (v) A guidance book for official voluntary decontamination by citizens was distributed by Kashiwa city office. The systematic framework for voluntary decontamination by citizens in Kashiwa city was developed through cooperation between a local government and decontamination experts, which was rare at that time. The authors believe that the process is valuable and should be shared with experts from various fields around the world.