Distribution of the 134Cs/137CsĀ ratio around the Fukushima Daiichi nuclear power plant using an unmanned helicopter radiation monitoring system

Yukiyasu Nishizawa, JAEA Japan Atomic Energy Agency, fukushima city, Japan and Tatsuo Torii, JAEA Japan Atomic Energy Agency, Remote Sensing Div., CLADS, Nucl. Sci. Res. Inst., Tokai-mura, Japan