Japan’s Last Nuclear Reactor to Go Off-line

Nation faces electricity shortfalls if nuclear power is not restored

3 min read

Japan’s Last Nuclear Reactor to Go Off-line

Special Report: Fukushima and the Future of Nuclear Power

Editor's Note: This is part of the IEEE Spectrum special report: Fukushima and the Future of Nuclear Power.


Photo: Kyodo/Reuters
Lights Out: Hokkaido Electric Power Company's Tomari nuclear power plant is scheduled to shut down this week. When that's done, Japan's will have no nuclear power feeding its grid.  Click on image to enlarge.

2 May 2012—Japan’s last operating nuclear reactor, Hokkaido Electric Power Co.’s No. 3 unit, at its Tomari plant in northern Japan, will shut down for a scheduled inspection on 5 May. This will leave Japan without any nuclear-generated power, something that hasn’t happened since the nation’s first commercial plant went on line in 1966.

Japan has 54 reactors. Aside from the four damaged Fukushima Dai-ichi reactors and several others out of service over safety concerns, the rest lie idle as they undergo government-ordered stress tests—a mandate that followed last year’s massive 11 March earthquake and tsunami.

The government had hoped to have several reactors back on line as early as May to head off newly predicted power shortages during Japan’s hot, humid summer, when electricity demand peaks. To this end, Yukio Edano, Minister of Economy, Trade, and Industry, lobbied the local government in Fukui Prefecture, in central Japan, to agree to restart the No. 3 and 4 units at Kansai Electric Power Co.’s (KEPCO) Ohi nuclear plant. These units (each with a capacity of 1.18 gigawatts) are the first to pass plant operators’ self-administered stress tests and to have the results positively reviewed by two government nuclear safety agencies and approved by a “wise men” group of four government ministers, including Edano. 

The local economies of Ohi and other nearby towns hosting KEPCO nuclear plants are heavily reliant on funding and subsidies that come from housing these facilities. Consequently, local officials were receptive to Edano’s entreaties. But then the governments of nearby prefectures and cities, such as Kyoto and Osaka, where antinuclear activism is much stronger, voiced loud opposition. They also accused the central government of “hasty” decision making.

“I’m against restarting the Ohi reactors right now,” Osaka mayor Toru Hashimoto told reporters. “Restarting them based just on the results of the stress tests is impossible. All sorts of questions, including safety concerns and whether or not there will be electricity shortages without them, have to be considered.”

“Legally speaking, the central government doesn’t need the endorsement of the adjacent city and prefectural governments,” points out Kazuaki Matsui, executive director of the Institute of Applied Energy, an independent research organization in Tokyo. “But unfortunately, it’s no longer just a safety issue. It’s become a political battle, so we don’t know what will happen.”

The Osaka mayor’s questioning of energy shortages came as the government published an electricity supply-and-demand outlook using data from nine power utilities that assumes no nuclear reactors are restarted by summer. The report, released on 23 April, further assumes that electricity-saving measures are similar to those carried out in last summer in the wake of the Great East Japan Earthquake. KEPCO is estimating by far the biggest shortfall—16.3 percent—assuming that demand peaks at 179 GW as it did in summer 2010. Only two other operators, Hokkaido Electric Power Co. and Kyushu Electric Power Co., are predicting shortfalls: both of less than 4 percent.

Edano, who is also being criticized by business groups for not yet producing a plan to cope with possible power shortages, says he’ll announce such a plan by mid-May. He also told the newspaper Mainichi Shimbun that should “all nuclear power plants remain out of operation, it will force unreasonable power restrictions and electricity price increases, small- and medium-size companies will collapse, and employment will become unstable in a chain of events that will cause confusion in society.”

Meanwhile, the news only gets worse for supporters of nuclear energy. Since the 11 March 2011 earthquake, the Nuclear and Industrial Safety Agency has been reassessing the seismic safety of nuclear plants near fault lines. Last week, it warned the Japan Atomic Power Co. (JAPC), the operator of the Tsuruga nuclear power plant in Fukui Prefecture, that faults near the plant may have become active.

JAPC says it is investigating the situation. Depending on its findings, the company could be forced to revise its safety standards. Such a revision will likely adversely impact the outcome of the stress tests, which must be passed before a plant’s reactors can be reactivated.

This news comes on the heels of the Tokyo metropolitan government releasing a report that predicts some 10 000 people could die and about 300 000 buildings could be destroyed in Tokyo if a 7.3 magnitude earthquake were to strike Tokyo Bay. A major quake there is predicted for some time in the future, because Tokyo is located near the intersection of two tectonic plates.

About the Author

John Boyd covers technology in Japan. In our November 2011 special report “Fukushima and the Future of Nuclear Power” he and Eliza Strickland laid out the messy future of the Fukushima Dai-ichi site.


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