[2D_PL02] Basic properties of fission products and their behavior under severe accident
The decommissioning of Fukushima Daiichi NPP will be terminated by identifying distributing location of fuel debris in the reactors, taking all of them out and depositing them safely for a long period. Environmental release of radioactive materials and, at the same time, occupational exposures of the decommissioning workers should be minimized during the decommissioning work for more than 40 years. One of the obstruction items for the decommissioning works is harmful effects of radioactive fission products (FP), e.g., 137Cs and 134Cs. In the session, basic properties of fuel debris and FPs are introduced, differences in their behaviors shown during the decommissioning works are pointed out and then it is intended that important suggestion for mitigation of radioactivity release and occupation exposure are applied for the steady and safe decommissioning works.