[2C10-16] Fukushima 2

3:15 PM - 3:30 PM JST(6:15 AM - 6:30 AM UTC)

[2C12] Investigation on distribution of radioactive substances in Fukushima(7) Model Development for Elucidation of Cs-137 Adsorption and Desorption Process in River Bottom Sediment in Fukushima Prefecture

*Naoyuki Wada¹, Yuichi Onda², Jim Smith³, Yasunori Igarashi² (1. University of Tsukuba, 2. Center for Research in Radiation, Isotopes and Earth System Sciences, 3. University of Portsmouth)

Keywords:

Cs-137,The Fukushima Daiichi Nuclear Power Plant,River-bottom sediment,desorption/adsorption model,Distribution coefficient

The Fukushima Daiichi Nuclear Power Plant accident in March 2011 released large amounts of Cs-137 into the atmosphere, which was quickly deposited on land. Focusing on the river bottom soil will enable us to elucidate the dynamics of Cs-137 during normal water conditions. In this study, a box model assuming adsorption and desorption between solid and liquid was developed. By reproducing the measured river-bottom sediment Cs-137 concentration in the model, the reaction rate of adsorption and desorption in the field is evaluated. In fact, the model was able to sufficiently reproduce the river-bottom sediment Cs-137 concentration in the field, and it was found that the variation was governed by the Kd, which differed at each sampling site.