Japan's nuclear watchdog on Wednesday approved plans to decommission two reactors in Fukui Prefecture, a move their operator decided to take rather than shoulder the high cost of implementing safety upgrades.

Kansai Electric Power Co. will spend 118.7 billion yen ($1.1 billion) to dismantle the Nos. 1 and 2 units at the Oi nuclear power plant, with work expected to wrap up in the fiscal year ending March 2049.

The units, which each have an output capacity of more than 1 million kilowatts, are the most powerful reactors to have decommissioning plans greenlit by the Nuclear Regulation Authority since a magnitude-9.0 earthquake and subsequent tsunami in March 2011 caused a meltdown at the Fukushima Daiichi plant.

Following the disaster, the government placed a 40-year limit on the lifespan of reactors in the country, with a possible 20-year extension if strict safety standards are met.

Kansai Electric had a choice of whether to apply for the extension -- both units came online in 1979 and were approaching the 40-year limit -- or decide to scrap them.

In December 2017, the utility announced it will scrap the aging reactors, citing the high cost of implementing additional safety measures. Kansai Electric submitted the decommissioning plan to the authority November 2018.

The plant's Nos. 3 and 4 units came online in 1991 and 1993, respectively, and are currently active.

Around 23,000 tons of low-level radioactive waste will come out of the dismantling process, according to the plan, along with another 13,200 tons of non-radioactive waste. The plan does not state where the waste will be kept.

==Kyodo

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