Challenges for management of radioactively contaminated wastes and volume reduction and reuse/recycling of removed soil derived from the activities for environmental remediation after the Fukushima Daiichi Nuclear Power Station accident

This is the overview of the following five speeches presented at the annual meeting of the Japan Atomic Energy Association in 2017: (1) comprehensive management of contaminated waste, (2) mechanism of Cs adsorption/desorption to clay minerals, (3) national strategy for technological development of volume reduction and recycling, (4) safety assessment of recycling use, and (5) disposal cost. In (1), the following are described: initial action for radioactively contaminated waste, current state of contaminated waste, characteristics of contaminated waste, and points of attention in landfilling at final disposal sites. In (2), the following are reported: adsorption mechanism to clay, physical decontamination and volume reduction, and heat treatment and recycling use. The contents of (3), which are the reports of the Ministry of the Environment on technological development strategy, are the promotion of recycling use, directionality study on final disposal, and fostering national people's understanding. There are also reports on basic ideas on safe use. In (4), the following are described: evaluation of the radioactivity concentration level that can be recycled, additional radiation dose assessment for examining conditions for further dose reduction to the general public at the time of reuse, dose reduction to the general public at the time of reuse, and additional radiation dose assessment at the time of disaster. In (5), the following are described: cost estimates method, and knowledge obtained from cost evaluation. (A.O.)