OSAKA -- Shikoku Electric Power is joining the ranks of Japanese utilities that have decided to pull the plug on aging nuclear reactors that are too costly to maintain.
The company, which serves the western Japanese island of Shikoku, plans to decommission the No. 1 reactor at its Ikata nuclear power plant in Ehime Prefecture.
The reactor, currently offline, began operating in September 1977 and will reach the 40-year government-mandated limit on the operational life of nuclear reactors in 2017. Shikoku Electric can extend the reactor's life span to 60 years should it submit a petition to Japan's Nuclear Regulation Authority by September.
Shikoku Electric had been evaluating whether an extension would make economic sense. It has concluded that the reactor, which has a relatively small output capacity of 566,000kW, would not contribute enough to its earnings to justify a massive investment. Making the necessary updates, such as fireproofing power cables that are key to safely running the reactor, will cost roughly 200 billion yen ($1.77 billion), according to the utility's estimate.
Shikoku Electric halted all three reactors at Ikata, its only nuclear plant, after the 2011 earthquake. The facility now has one of the best safeguards in the country against earthquakes and tsunamis. The No. 3 reactor, its newest which came online 21 years ago, passed the nuclear watchdog's inspection last summer. The company will apply for another screening on Friday, and hopes to restart the No. 3 reactor in July.
Japanese power companies decided last spring to decommission five nuclear reactors due to their age and other factors, including two at Kansai Electric Power's Mihama plant and the No. 1 reactor at Chugoku Electric Power's Shimane plant.
Kansai Electric has petitioned the nuclear regulator to extend the lives of two reactors at its Takahama plant, which have passed the 40-year limit. It also applied for an extension for its No. 3 reactor at Mihama, but the projected costs of required updates have ballooned from its original plans and could force the company to choose a shutdown instead. Shikoku Electric's decision could affect other nuclear reactors whose fates are still up in the air.
To be exempt from the 40-year rule, reactors must pass an inspection by the nuclear watchdog based on newly established safety standards. But it is said to cost at least around 100 billion yen to update one nuclear reactor. The actual figure often ends up even higher, due to necessary steps such as retrofitting facilities to resist earthquakes.
Investing this much in large reactors with an output capacity of about 1 million kilowatts is believed to make economic sense, since they contribute enough to companies' earnings. But smaller reactors with capacities of about 500,000kW are not considered worth the cost.