Fukushima mapping project after the Fukushima Dai-ichi Nuclear Power Station accident

Mikami, Satoshi   

An enormous amount of radionuclides were released from the Fukushima Dai-ichi Nuclear Power Station accident, and part of them were deposited on ground in Japan. In order to obtain basic data to evaluate the impact of the accidental release, a national project for comprehensive environmental monitoring was launched in June 2011, and is still continuing. In the so-called Fukushima mapping project, a series of large-scale environmental monitoring with diverse methods have been conducted, aiming to obtain information on contamination conditions in different aspects This article presents the measurement methodologies for distribution mapping of air dose rates and radionuclides deposition density adopted in our mapping project, and also discuss the temporal change in air dose rate and radiocesium deposition density through repeatedly conducted measurements.