1st East Japan Reactor Restarted since 2011 Fukushima Crisis
Ishinomaki/Onagawa, Miyagi Pref., Oct. 30 (Jiji Press)--Tohoku Electric Power Co. restarted the No. 2 reactor at its Onagawa nuclear power plant in Miyagi Prefecture on Tuesday, making it the first reactor to come back online in eastern Japan since the March 2011 Fukushima nuclear crisis.
This is also the first restart since the nuclear crisis of a boiling water reactor, the type of reactors crippled at Tokyo Electric Power Company Holdings Inc.'s Fukushima No. 1 plant in Fukushima Prefecture, south of Miyagi, following the 9.0-magnitude earthquake and subsequent tsunami on March 11, 2011.
"The restart of a nuclear plant in eastern Japan is extremely important," Japanese industry minister Yoji Muto told a press conference on the day.
Tohoku Electric and TEPCO have relied on thermal power generation since halting their nuclear reactors following the Fukushima accident. As a result, their electricity rates are about 20 pct higher than those of Kansai Electric Power Co. and Kyushu Electric Power Co., which have restarted a total of 11 nuclear reactors.
At 7 p.m. Tuesday, an official at the Onagawa plant's central control room counted down from three and flipped the switch to change the operational status of the No. 2 reactor, which reached criticality, or a self-sustaining nuclear chain reaction, at 12:12 a.m. Wednesday after the 137 control rods that suppress nuclear fission in the reactor were removed one by one.
The reactor is slated to resume power generation on Nov. 7 at the earliest, but will be temporarily halted for fresh inspections as it has been offline for as long as 13 years. The reactor is expected to resume commercial operations around December.
The restart of the Onagawa plant will "further enhance the reconstruction of the Tohoku (northeastern Japan) region following the earthquake" in March 2011, Tohoku Electric President Kojiro Higuchi said in a statement.
"Additionally, this restart will provide great significance from the perspectives of both carbon neutrality and the stable supply of electricity," Higuchi noted. He added that the company will continue to strengthen efforts to build trust with local residents.
Miyagi Governor Yoshihiro Murai issued a statement calling on Tohoku Electric to "work with a sense of tension while putting safety first."
Masami Saito, mayor of Ishinomaki, said the city wants the power company to give careful explanations to local residents, while Yoshiaki Suda, mayor of Onagawa, said the town will closely monitor the restart process. The plant straddles the two municipalities.
In the March 2011 disaster, the Onagawa plant's No. 1 to No. 3 reactors were hit by a tsunami as high as about 13 meters. At the time, the No. 1 and No. 3 units were in operation, while the No. 2 reactor was in the process of being activated.
Although some emergency generators stopped functioning due to seawater flowing into the plant after the tsunami, external power sources were available, allowing all Onagawa reactors to be brought to a state of cold shutdown.
Tohoku Electric spent a total of about 570 billion yen on construction to ensure the plant's safety, such as raising the height of seawalls from 17 meters above sea level to 29 meters and newly erecting a wall to prevent tsunami from entering water intake channels.
Following the Fukushima accident, Japan introduced new regulatory standards for nuclear plants in 2013. Excluding the Onagawa No. 2 reactor, 12 reactors have been restarted so far after being found to meet the new standards. The 12 are pressurized water reactors located in western Japan.
Among other boiling water reactors in the country, Chugoku Electric Power Co. aims to restart the No. 2 reactor at its Shimane nuclear power plant in western Japan in early December.
The resumption of the Onagawa No. 2 reactor is seen reducing Tohoku Electric's costs by about 60 billion yen per year, but the company is cautious about lowering its prices, which have already been set based on the assumption of the restart of the reactor.
Meanwhile, TEPCO is working to restart the No. 7 reactor at its Kashiwazaki-Kariwa nuclear plant in Niigata Prefecture, central Japan, but it has yet to win the understanding of local residents.
TEPCO's efforts to restart the reactor may face higher hurdles after candidates from the main opposition Constitutional Democratic Party of Japan, which is cautious about nuclear power use, won all five Niigata constituencies in Sunday's general election, a company source said.
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