Updating source term and an atmospheric transport, dispersion and deposition model, WSPEEDI

Nagai, Haruyasu  ; Terada, Hiroaki   ; Tsuzuki, Katsunori  ; Ota, Masakazu  ; Furuno, Akiko   ; Akari, Shusaku; Katata, Genki

In order to assess the radiological dose to the public resulting from the Fukushima Daiichi Nuclear Power Station accident in Japan, the spatial and temporal distribution of radioactive materials in the environment are reconstructed by computer simulations. In this study, by refining the source term of radioactive materials discharged into the atmosphere and modifying the atmospheric dispersion model, the atmospheric dispersion simulation of radioactive materials is improved. Then, a database of spatiotemporal distribution of radioactive materials in the air and on the ground surface is developed from the output of the simulation, and is used for the dose assessment by coupling with the behavioral pattern of evacuees from the nuclear accident. In this year, (1) investigation of the source term, (2) improvement of atmospheric dispersion simulation, and (3) acquisition and organization of measured data have been conducted.