Methodologies applied to air dose rate monitoring after the Fukushima Dai-ichi Nuclear Power Plant accident and their applications for lifting evacuation orders

Yoshimura, Kazuya  ; Sanada, Yukihisa   

The Japanese government has been continuously monitoring air dose rates over a wide area by various methods to assess contamination of land areas, after the Fukushima Daiichi Nuclear Power Plant accident. The monitoring methods have different purposes, characteristics, and advantages. These monitoring results have been used as basic data for the reorganization of evacuation-ordered zones and for the lifting of evacuation orders. Creating detailed air dose rate maps, dose assessments, and risk communication with residents using the information are examples of the applications of the monitoring results.