Source term estimation for the 2011 Fukushima nuclear accident

Abstract

A new methodology is presented for the reconstruction of an unsteady release rate of an atmospheric contaminant, based on atmospheric transport and dispersion models, concentration measurements, and stochastic search techniques. The methodology is applied to reconstruct the radiation release rate for the March 2011 Fukushima nuclear accident.The observed radiation data were retrieved from 218 stations located in 17 Japanese prefectures. The dispersion simulations are performed using the SCIPUFF model, using model vertical profiles and ground meteorological data. The non-stationary time-series of the Fukushima release rate is determined for a period of 5 days with a 2-h resolution.