Utilization and development of evacuation time estimates in wide-area evacuation planning for nuclear disasters in Japan

At the time of the nuclear accident at the Fukushima Daiichi nuclear power plant in March 2011, approximately 150,000 people evacuated across a wide area in response to the accident and that caused great confusion. Since this accident, the nuclear emergency preparedness has been reviewed in Japan, and wide-area evacuation plans have been revised in the local government surrounding the nuclear power plant. It is extremely important to establish a wide-area evacuation plan. Then, computer simulation called evacuation time estimation (ETE) is utilized to consider such a wide-area evacuation planning. This is to build an artificial society including population and road network on a computer, and to simulate the evacuation situation. For a large-scale evacuation, it is important to grasp in advance the time that evacuation takes and issues at the evacuation. Then, it is utilized to figure out a tendency of the evacuation situation and extract the issues such as congestion, and to consider measures to address such issues and verify the effects of those measures. To date, we have conducted more than 15 ETE projects in more than 10 years for local governments around nuclear power plants. Here, we describe the utilization of ETE in nuclear emergency preparedness in Japan and its effects, its development, and current issues.