Study on long-term radiation exposure analysis after the Fukushima Dai-ichi nuclear power plant accident: validation of the EU long-term radiation exposure model (ERMIN)

Abstract

The Fukushima Dai-ichi nuclear power plant accident led to the dispersion of radioactive material by wind that resulted in soil and air pollution over a wide area. Even now, more than 150,000 people in Fukushima prefecture are still relocated from their homes. In order to estimate how long such relocation might continue, we estimated radiation exposures for the 10 years following the accident that occurred on 12 March 2011, using European model for inhabited areas (ERMIN) developed by a partnership of several European organizations. We validated the estimated results of long-term radiation exposure with the observed data at 1, 2 and 3 years after the nuclear accident. We analyzed the deposition velocity and re-suspension coefficient using the observed data on air concentration, amount of falling dust and soil contamination, and compared them with the published data.

The Concentrations and Removal Effects of PM10 and PM2.5 on a Wetland in Beijing

“…According to Kim's paper, the resuspension does not occur under wind conditions of lower than 3 m/s [30], therefore, the resuspension effect was neglected in this study. Based on resistance theory, deposition velocity is mainly determined by the roughness of subsurface and resistance from the constant layer and quasi laminar boundary layer [29][30][31][32][33]. Previous studies in Beijing conclude that the resistance is determined by the atmosphere conditions, wind speed specifically, and conclude an empirical model to calculate the deposition velocity [34,35].…”

“…Due to the difference between Equation (3) in this study and the empirical formula of NUREG/CR-7161, the deposition velocities of PM 10 and PM 2.5 were considered as a whole and were not regarded as an independent variable here. Even so, compared with the results acquired from the empirical formula which used the cumulative probability density function of deposition velocity (NUREG/CR-7161; Z 0 = 10 m, V = 2 m•s −1 ) [30], the distribution tendency of the data on the wetland and bare land in this study agreed with this formula, as well as the ranging from 0.0001 to 1.2263 cm•s −1 , as shown in Figure 5. The structure of this model is relatively simple, and the data required are easy to collect compared with the physical process-based model [35].…”

Summary report of recent activities for decontamination and environmental restoration after Fukushima Daiichi nuclear power plant accident

“…Air concentrations of 133 Xe, 131 I, 132 I, 133 I, 132 Te, 134 Cs, 136 Cs, and 137 Cs in the early stage after FDNPP accident were estimated for six locations in Ibaraki Prefecture, Japan, from pulse height distributions measured with NaI(Tl) scintillation detectors continuously operated as a part of monitoring station systems [32]. For validation of the EU long-term radiation exposure model, long-term radiation exposure analysis after FDNPP accident was studied [33].…”