(Bloomberg) -- Japan’s nuclear power recovery has hit a surprise speedbump.

The Nuclear Regulation Authority refused to extend deadlines for utilities to build emergency facilities for reactors in the event of a terrorist attack and will shut the units if the construction isn’t finished in time, officials from the agency said during a meeting Wednesday. The decision may impact at least 10 reactors operated by Kyushu Electric Power Co., Kansai Electric Power Co. and Shikoku Electric Power Co., whose shares declined.

“Today’s decision was very severe,” a Shikoku spokesman said. “We will do what we can to shorten our construction timeline and meet the deadline.”

The surprise move is the latest setback for Prime Minister Shinzo Abe’s government, which wants nuclear power to account for at least 20 percent of the nation’s energy mix by 2030. Opposition from local governments and temporary injunctions from courts have slowed restarts of Japan’s atomic fleet, forcing operators to shut reactors for months or years. Kyushu Electric and Kansai Electric weren’t immediately available for comment.

The NRA “wasn’t expected to make such tough decision on this issue,” Reiji Ogino, an analyst at Mitsubishi UFJ Morgan Stanley, said by phone. “It’s negative for power companies as it’s an entirely new risk” that could lead to shutdowns of operating reactors.

Share Plunge

Kyushu Electric fell 5.8 percent to 1,094 yen a share, the lowest close since November 2016. Kansai Electric slumped 7.8 percent and Shikoku Electric declined 5 percent.

Seven of the reactors that likely won’t make the deadline have restarted under post-Fukushima safety rules. Japan has only restarted nine of its 37 operable reactors under the new guidelines.

The anti-terrorism guidelines require operators to build separate buildings that include backup power and water pumps for reactors, as well as an emergency meeting room for workers. The facilities are intended to help avoid meltdowns -- like the 2011 Fukushima disaster -- in the event of a terrorist attack, such as being hit by a hijacked airplane.

Below is a list of the reactors seeking extension and the NRA-imposed deadlines for retrofits to be completed.

To contact the reporters on this story: Stephen Stapczynski in Singapore at sstapczynsk1@bloomberg.net;Tsuyoshi Inajima in Tokyo at tinajima@bloomberg.net

To contact the editors responsible for this story: Ramsey Al-Rikabi at ralrikabi@bloomberg.net, Ben Sharples, Aaron Clark

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