292 2011 Vol.60 No.4 p.292 299 Atmospheric behavior of radioactive materials from Fukushima Daiichi Nuclear Power Plant Toshimasa OHARA, Yu MORINO, Atsushi TANAKA National Institute for Environmental Studies Abstract The nuclear accident in Fukushima Daiichi Nuclear Power Plant (FDNPP) accompanying the Great Tohoku Earthquake and Tsunami on 11 March 2011 resulted in the release of enormous amounts