[2A06-09] Fukushima Daiichi Nuclear Power Plant Accident: Enviornmental Assessment

[2A07] Radiocaesium at coastal region of Japan in 2011-2016 derived TEPCO Fukushima Dai-ichi Powler Plant Accident

*Michio Aoyama¹, Yasunori Hamajima², Yayoi Inomata², Yuichiro Kumamoto³, Eitarou Oka⁴, Takaki Tsubono⁵, Daisuke Tsumune⁵ (1. Institute of Environmental Radioacticity, Fukushima Univ., 2. Institute of Nature and Environmental Technology, Kanazawa University, 3. Research and Development Center for Global Change, Japan Agency for Marine-Earth Science and Technology, 4. Atmosphere and Ocean Research Institute, the University of Tokyo, 5. Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry)

Keywords:radiocaesium, recirculation, coastal region, Fukushima NNP accident

Radiocaesium (134 Cs and 137 Cs) released by the TEPCO Fukushima Daiichi Nuclear Power Plant (FNPP 1) accident that occurred in March 2011 was injected directly and the atmospheric deposition in the North Pacific Ocean. We report on the long term behavior of the radiocaesium across the coast of Japan through the end of 2016. The intensive observation results from November 2015 to May 2016 indicate that a small part of the FNPP1-derived radiocaesium has already recirculated through the surface layer of the western North Pacific Ocean, and that the recirculated radiocaesium reached the Japanese coast within a period of several years after the accident.