Big Reactors to Die

Kansai Electric Power Company decided that it would dismantle the reactor #1 and #2 in Oi Nuclear Power Plant in Fukui. They would be the first reactors with high output over 1 million kilowatts to be dismantled after the severe accident in First Fukushima Nuclear Power Plant in 2011. Even a big nuclear reactor, which has been recognized as more efficient than smaller ones, is proved to be unable to survive in the strict regulation on nuclear business.

Each of two reactors in Oi Plant has 1.175 million kilowatts of output power. Their life will be ended in 2019, according to the regulation that all the reactors should not be used for more than 40 years. As exception with approval from Nuclear Regulation Authority, nuclear reactors can extend its life for more 20 years. Reactor #1in Oi Plant will face the time limit of application for the extension next March.

To apply the extension, KEPCO needs to have examination for the damages inside the reactor, which may take several months. New regulation after Fukushima accident requires strict safety measures against earthquake or tsunami, demanding higher cost. Since reactor #1 or #2 in Oi has complicated structure that makes reinforcement difficult, KEPCO seems to decide dismantle them to avoid further cost. Underground rifts around the plant, which would require expensive preventive measures, also caused the decision.

KEPCO had been depending one-half of its whole electric power supply on nuclear power generation before Fukushima accident. Affected by introduction of power retailing liberalization in April 2016, the company has been losing its clients. Although resumption of Oi Plant had to be the key element for regaining competitiveness, it proved to be too expensive to be affordable.

Each of the six rectors determined to be dismantled was with smaller output of 340 to 556 thousand kilowatts. The decision in Oi Plant may affect the fortune of other large reactors such as in Second Tokai Nuclear Power Plant. While the government of Japan has Energy Basic Plan that expects nuclear power generation to owe 20 to 22% of all electric power supply, retreat of large nuclear reactors can demand thorough review of the plan.

Only 14 rectors out of all 45 have passed examination of NRA so far. Electric power companies in Japan are getting more careful in applying resumption of nuclear reactors to the government. It is likely that the government will face two choices; one is to change the target of the share of nuclear power generation and another is to approve building new nuclear power plants.