A nuclear reactor in Miyagi Prefecture damaged by the 2011 earthquake and tsunami disaster formally cleared screening by a national nuclear watchdog on Wednesday, paving the way for it to restart after anti-disaster measures are completed by the end of March next year.
The No. 2 unit of Tohoku Electric Power Co.’s Onagawa plant won the approval of the Nuclear Regulation Authority, becoming the second disaster-damaged reactor, after the Tokai No. 2 power plant in Ibaraki Prefecture, to pass stricter safety standards introduced after the Fukushima nuclear crisis.
Construction of an 800-meter seawall is among anti-disaster measures that still need to be completed at the plant, which straddles the town of Onagawa and the city of Ishinomaki. The operator also needs to obtain consent from local residents before it can restart the plant.
On March 11, 2011, all three reactors at the Onagawa complex shut down when a massive earthquake rocked northeastern Japan and a 13-meter tsunami hit the area, flooding the underground floors of the No. 2 unit.
However, the facility’s emergency cooling system operated correctly and there was no meltdown of the type that occurred at Tokyo Electric Power Company Holdings Inc.’s Fukushima No. 1 plant.
Tohoku Electric applied for safety screening for the No. 2 unit in December 2013 and has been constructing the seawall that will top out at 29 meters above sea level. It expects to spend about ¥340 billion ($3.08 billion) in total on the anti-disaster measures.
The company has already decided to scrap the No. 1 reactor, which began operations in 1984, and is considering applying for the restart of the No. 3 unit, which started power generation in 2002.
When it restarts, the Onagawa No. 2 reactor, which began commercial operations in 1995, will be the first boiling water reactor — the same type used at the Fukushima No. 1 plant — to resume operations since the 2011 earthquake and tsunami hit. The disaster claimed nearly 16,000 lives and left more than 2,500 missing.
Other boiling water reactors at Tepco’s Kashiwazaki-Kariwa plant in Niigata Prefecture and the Tokai No. 2 plant of Japan Atomic Power Co. have already secured approval to resume operations from the regulator, but have yet to obtain local consent.