TOKYO (Reuters) - Three aging nuclear reactors in Japan will be decommissioned due to the high cost of upgrading them in line with tougher safety standards set after the Fukushima disaster, their operators said on Tuesday.
Another two reactors were also likely to be scrapped, local media reports said, with announcements expected later in the week.
The moves are the first concrete sign that Japan's nuclear industry is heeding a government request to shut down older reactors that are considered more vulnerable to natural disasters in the hope that it will ease public concerns about a restart of other reactors.
All 48 of Japan's nuclear reactors were taken offline after an earthquake and tsunami set off meltdowns at Tokyo Electric Power's Fukushima Daiichi plant in 2011.
As many as two-thirds of the country's reactors may never return to operation because of high costs, local opposition or seismic risks, a Reuters analysis showed last year.
Kansai Electric Power, which depended on its nuclear fleet for nearly half of its total power output before 2011, said on Tuesday it would scrap its Mihama No. 1 and No. 2 reactors. Japan Atomic Power said it would decommission its Tsuruga No. 1 reactor.
Kyushu Electric Power and Chugoku Electric Power are both expected to announce their plans to scrap two old reactors on Wednesday.
The five reactors are among Japan's oldest, ranging in age from 39 to 44 years, and have relatively low generating capacity of up to 559 megawatts each.
It is the first time utilities have opted to close older reactors to comply with new safety standards set after the Fukushima disaster that limits a nuclear reactor's lifespan to 40 years unless it can clear tough rules for a one-time extension. The deadline to apply for that extension is July 2015.
Japan's trade ministry has been pushing nuclear operators for a quick decision on scrapping aging reactors that are too costly to upgrade, promising financial support for a smooth decommissioning.
Japan has revised accounting rules to allow utilities to spread the write-offs for reactor closures over 10 years and to pass on some of the cost to ratepayers.
For Japan's newer plants, Prime Minister Shinzo Abe has said his government will restart reactors that have won approval from the nuclear regulator.
So far, Kyushu Electric's two-reactor Sendai plant and Kansai Electric's No. 3 and No. 4 Takahama reactors have cleared initial safety checks.
(Reporting by Kentaro Hamada; Editing by Richard Pullin)