The Mito District Court ordered the suspension of Japan Atomic Power Co.'s Tokai No. 2 Power Station on March 18, citing lack of preparation for an effective evacuation plan in the event of a serious accident, and that local residents' safety was not ensured.
It is the nation's first judicial decision banning a nuclear power plant's operations simply because of inadequate evacuation plans.
Absolute safety does not exist when operating nuclear power plants. If a serious accident occurs, widespread damage will occur, and evacuating residents will be extremely difficult. The Fukushima Daiichi Nuclear Power Station accident 10 years ago is testament to that fact.
The International Atomic Energy Agency imposes five layers of safety measures on nuclear power plants, with an evacuation plan as the last resort. Currently, local governments within 30 kilometers of a nuclear plant are required to formulate corresponding evacuation plans.
The Tokai No. 2 Power Station is the only nuclear plant in the Tokyo metropolitan area, and is currently out of operation. About 940,000 residents live within 30 kilometers of it, the largest concentration of people around an atomic power station in Japan.
Of the 14 municipalities in its orbit, nine local governments including the Ibaraki Prefecture capital of Mito, which has a population of approximately 270,000, have yet to formulate evacuation plans.
The ruling stated evacuation plans that have been devised by the five remaining municipalities and the Ibaraki Prefectural Government were also inadequate, with shortcomings including failures to provide multiple evacuation routes in the event roads are cut off in disasters.
Many people would have to evacuate in a potential disaster, meaning effort will be required to coordinate with other municipalities accepting evacuees and secure transportation for them. Outlining an evacuation plan for the area is, from the start, a difficult task.
The district court's ruling may also affect other nuclear plants' operations.
Even at nuclear plants that have already restarted or are undergoing procedures to restart, evacuation routes and transportation systems are limited, and questions hang over the effectiveness of their evacuation plans.
Nuclear plant operators now have a heavier responsibility. Though evacuation plans are mainly formulated by local governments, it will now be necessary for plant operators to also get further involved.
Evacuation plans are not subject to review by the Nuclear Regulation Authority. Even if it endorses nuclear power stations' safety measures, anxiety among residents will not be dispelled unless the evacuation plan, drawn up in case of an emergency, is sufficient.
The latest ruling is the eighth judicial decision since the March 2011 Fukushima Daiichi Nuclear Power Station accident to disallow the operation of a nuclear plant. Courts are casting an increasingly stern gaze on the issue.
The national government should take the response seriously, and review its policies with a view to breaking away from nuclear power generation.