Japan’s nuclear watchdog gave approval Wednesday for the nation’s third reactor to operate beyond the mandated 40-year maximum life span as the enforcement of limits introduced after the Fukushima disaster continues to weaken.
The No. 3 unit at Kansai Electric Power Co.’s Mihama plant in Fukui Prefecture is the latest reactor given the approval following two units at the utility’s Takahama complex, also in Fukui.
The 40-year operational limit was part of tougher safety requirements introduced by the Nuclear Regulation Authority after the Fukushima disaster. It was meant to encourage operators to retire aging reactors that could be prone to accidents.
Although a 20-year extension of operations is possible, nuclear regulators had initially indicated that it would, in practice, be extremely difficult to get approval for such a move.
Some officials in Fukui and neighboring Shiga and Kyoto prefectures have expressed safety concerns over reactors that are more than 40 years old and questioned the necessity of restarting the aging facilities.
The Mihama reactor, which began commercial operations in December 1976, went offline in May 2011 for a regular checkup. The unit’s operations have been suspended ever since, while it underwent the new safety screening.
To meet the new regulations, Kepco plans to spend about ¥165 billion ($1.5 billion) to upgrade the facilities at the reactor, which has a capacity of 826,000 kilowatts.
The reactor is not expected to be rebooted before spring 2020 to allow time for Kepco to put in place the required safety measures, it said.
The utility said in a written statement that it hopes to “smoothly resume the operation of reactors whose safety is confirmed,” adding it will start planning the upgraded safety measures that are to be included as soon as possible.
Elsewhere, the company is considering extending the operation period for the Nos. 1 and 2 reactors at its Oi nuclear power plant located on the coast near the Sea of Japan. Both reactors began commercial operations nearly 37 years ago.
Some utilities have decided to scrap their aging reactors amid soaring safety costs. Kepco has given up restarting the two other reactors at the three-unit Mihama plant.
A total of six reactors at five plants in the country will be scrapped under the 40-year rule.