Japan has had all of its 50 reactors offline as the country runs safety tests following the 2011 Fukushima Daiichi atomic disaster. Above, the reactor buildings at Fukushima as seen in May 2012.The move, which could take effect as soon as next week, comes after local leaders from western Japan backed away from their opposition, giving provisional support to a restart of the two reactors, located at Kansai Electric Power Co.'s 9503.TO +3.18% Oi plant.
"I effectively accept" a restart of the reactors, provided it is on a temporary basis, to help deal with expected power shortages in the peak summer period, Osaka Mayor Toru Hashimoto said at a city-office news conference Thursday. "It's time to stop superficial arguments."
Without the restart of the two powerful reactors, the government said, the area covered by the Oi complex, which includes the city of Osaka, would face power shortages of up to 15%. The two reactors are expected to largely eliminate that shortfall, but don't guarantee a swift return of other idled plants. Opinion polls continue to show the public is looking for a long-term exit from nuclear power.
The threat of power shortages and a possible exodus of businesses from the region—now a hub of electronics makers such as Panasonic Corp. and Sharp Corp.—helped fracture the unity of the local opposition.
The government's nuclear minister, Goshi Hosono, won agreement from local leaders in a meeting Wednesday by promising that no other reactor will be restarted until an independent nuclear regulator is created—likely after summer. All of Japan's nuclear reactors were eventually shut down after the March 2011 nuclear disaster.
The local leaders issued a statement Wednesday that any restart should be a temporary measure.
The abrupt about-face of Mayor Hashimoto, a tough critic of the Noda administration and a man seen as the voice of growing political dissatisfaction in Japan, deprived the local leaders' group of a rallying point in their opposition, resulting in their rapid climb-down.
"We have put across our concerns to the government. We have fulfilled our responsibility as local government leaders," Katsunori Ishida, spokesman for the local leaders' group, said.
The government must now get the approval of the governor of Fukui prefecture, where the Oi plant is located, and the local assembly. Gov. Issei Nishikawa, a past proponent of nuclear energy, is expected to endorse the move.
Mr. Hosono is set to be dispatched to the prefecture to explain a plan to create stronger safety oversight of the plant—including the temporary stationing of a deputy minister there and the permanent assignment of plant engineers.
"I will make a final decision on the restart at my own responsibility," Mr. Noda said in a news conference Wednesday.
On May 5, the last operating reactor went offline, depriving the country of an energy source that used to account for over 30% of its power supply. The government has since been warning of serious power shortage, especially in western Japan where reliance on nuclear power is much greater than in the eastern half.
On May 18, the government announced a plan to ask households and businesses in the service area of Kansai Electric to reduce power usage by at least 15% during summer, compared with peak levels in 2010.
Gov. Yukiko Kada, who leads Shiga prefecture next to Fukui, where the Oi plant is located, stressed Wednesday that she will still press the government to proceed cautiously with a restart. Her office also said the governor hasn't dropped her tough demands, including a clear road map for Japan exiting nuclear power.