Application of numerical simulation system of JAEA to predict the environmental transport of radioactive materials discharged from the Fukushima Nuclear Power Plant

Nagai, Haruyasu  ; Chino, Masamichi; Terada, Hiroaki   ; Katata, Genki; Nakayama, Hiromasa   

Japan Atomic Energy Agency has been applying its numerical simulation system to predict the environmental transport of radioactive materials discharged from Fukushima Daiichi Nuclear Power Plant. As the first step, the source term of radioactive materials discharged from the plant into the atmosphere has been estimated by coupling environmental monitoring data with atmospheric dispersion simulations by SPEEDI and WSPEEDI under the assumption of unit release rate (1 Bq/h). As the next step, we are planning to apply our numerical simulation system for material transport in the atmospheric, terrestrial, and oceanic environments, SPEEDI-MP. The method and preliminary results of source estimation and our future plan will be presented.