B13A-0592
Radioactive sediment transport and accumulation in the mouth of the Ukedo River
Monday, 14 December 2015
Poster Hall (Moscone South)
Susumu Yamada1, Akihiro Kitamura1, Hiroshi Kurikami2, Masahiko Okumura3 and Masahiko Machida4, (1)JAEA Japan Atomic Energy Agency, Toki, Japan, (2)JAEA Japan Atomic Energy Agency, Fukushima Environmental Safety Center, Fukushima, Japan, (3)JAEA Japan Atomic Energy Agency, Center for Computational Science & e-Systems, Kashiwa, Japan, (4)Japan Atomic Energy Agency, CCSE, Naka-Gun, Tokai-Mura, Japan
Abstract:
The earthquake and tsunami on 11 March 2011 caused the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. The accident released the significant quantities of radionuclides to the atmosphere. The radionuclide which remains most in the environment is a radioactive cesium isotope. Therefore, we concentrate on the behavior of the cesium to predict the distribution and fate of the radionuclides in the environment. Cesium is an alkali metal and is strongly sorbed by soil particles, especially small ones. In addition, the movement of the soil particles is strongly affected by an aquatic system such as a river and a lake. Accordingly, when we simulate the sediment transport by the influence of the aquatic system, we can predict the behavior of the cesium. In this research, we concentrate on the behavior of the sediment around the mouth of the Ukedo River which is located in about 7 km north from FDNPP. Since its upstream was heavily contaminated by the radionuclides released from FDNPP, the contaminated soils flow from the upstream by a flood. Therefore, we examine the behavior of the sediment with utilizing the 2-dimensional river simulation code Nays2D and we reveal where the sediment accumulates at a flood. We believe that the result is very useful information for the effective decontamination of the contaminated soils.
