Japan Atomic Power Company’s (JAPC’s) ageing single unit Tokai II NPP in Ibaraki Prefecture has passed the Nuclear Regulation Authority’s (NRA’s) tougher safety standards, but still requires further NRA approvals to keep the plant in service after it reaches the government’s operational limit of 40 years on 27 November.
At a general meeting on 26 September, the five NRA commissioners unanimously agreed that safety measures submitted by the Tokai plant met the stricter safety standards that were introduced after the Fukushima Daiichi accident. Tokai II plant is the first NPP damaged by the March 2011 earthquake and tsunami to pass the NRA’s safety screening. The earthquake left the plant without an external power source, and the tsunami incapacitated one of its three emergency power generators. However, the plant managed to cool down its reactor over three and a half days after the disaster because the two other power generators remained operational.
Tokai II’s 1,060 MWe boiling-water reactor (BWR) is Tokai 2 is the 15th power reactor approved for restart by NRA and the third BWR to be approved, the other two BWRs being units 6 and 7 at Tokyo Electric Power Co’s (Tepco’s) Kashiwazaki-Kariwa NPP in Niigata Prefecture. The reactors that melted down at Fukushima Daiichi were also BWRs.
JAPC still needs NRA to approve detailed plans to implement the safety measures against possible disasters, such as the building of breakwaters. Construction work is scheduled to be completed in March 2021. NRA approval is also required to extend Tokai II’s operational life by 20 years beyond the 40-year limit. Once JAPC has completed all construction work needed for life extension, it will also have to get the consent of the prefectural government, the village of Tokai and five surrounding municipalities to restart the reactor.
NRA is in the final phase of screening the company’s applications for the extension as well as its detailed construction plans. However, JAPC is behind schedule in submitting the necessary documents for the extension. The company must also compile an evacuation plan covering the 960,000 residents within a 30-kilometre radius of the plant. This is the largest number of potential evacuees for any Japanese NPP because it is located in a metropolitan region.
JAPC applied for the restart in May 2014 with a plan to construct a 1.7km coastal levee, predicting a potential tsunami as high as 17.1 metres. Costs for safety measures at the plant are estimated at some JPY180 billion ($1.6 billion), and JAPC is in financial difficulty as none of its reactors has been online since the 2011 disaster. Tepco and Tohoku Electric Power Co, which receive electricity from Tokai II, have offered financial support. Tokai II began commercial operation in November 1978. Another reactor at the site, the 137MWe Tokai I Magnox unit, was permanently shut down in 1998 and is being decommissioned.
Elsewhere in Japan, the Hiroshima High Court on 25 September accepted an appeal by Shikoku Electric Power Co allowing it to restart unit 3 at its Ikata NPP in Ehime Prefecture, dismissing concerns about the dangers of potential volcanic activity in a nearby prefecture. This reversed an earlier provisional injunction that demanded that Shikoku should keep the plant closed until the end of September. The temporary suspension order, issued last December following a request from a local opposition group, was the first case of a high court prohibiting operations at a nuclear plant since the Fukushima accident.
In the new ruling, Judge Masayuki Miki said: “There is no reason to believe in the possibility of a destructive volcanic eruption during the plant’s operating period and there is only a small chance of volcanic ash and rocks reaching the plant,” which is about 130 kilometres away.
Shikoku Electric said it will restart Ikata 3, a 846MWe pressurised water reactor, on 27 October and begin sending power to the grid on 30 October. “The court decision to remove the injunction proves the facility’s safety,” Shikoku Electric President Hayato Saeki said in the statement. “We will begin preparing the facility to resume operations. The unit has been closed for maintenance since October 2017. Ikata 3 is Shikoku Electric’s largest power production facility and while it is offline, the company has to pay an additional JPY3.5 billion a month for power generation using fossil fuels. The company will have accumulated extra bills totalling JPY30 billion by the end of September.
However, residents in nearby Oita, Kagawa and Yamaguchi prefectures are also seeking to stop the reactor in pending court cases, and a request to extend the period of the injunction has been filed with the Hiroshima District Court. According to The Mainichi, citing Datsugenpatsu Bengodan, a group of lawyers who oppose nuclear power, there are some three dozen lawsuits pending against Japan’s nuclear facilities and the decision in favour of Shikoku may have some influence on future rulings. A nationwide survey by Mainichi Newspaper in February show the restart of nuclear reactors was opposed by almost half of the respondents, while about a third of them approved.
The latest ruling came after Kansai Electric Power Co won a decision in July allowing the restart of units 3 and 4 at its Ohi NPP in Fukui Prefecture. Kansai Electric has four reactors operating in Fukui, and has six more lawsuits before the courts. Kansai President Shigeki Iwane has repeatedly stated that winning the suits one by one will reduce the risk of future lawsuits.
