Tokyo Electric Power Company Holdings' (Tepco’s) Kashiwazaki-Kariwa NPP in northern Japan's Niigata prefecture has been approved for restart by the Nuclear Regulation Authority (NRA) more than two years after an order was issued for improvement of counterterrorism measures. NRA said the measures had been enhanced after inspections of the reactor complex However, Tepco still needs to obtain local consent. "We will listen to residents' opinions and make our decision," Niigata Governor Hideyo Hanazumi said.
Tepco has long wanted to resume operation of the Kashiwazaki-Kariwa plant to reduce its dependence on costly fossil fuel imports for non-nuclear thermal power generation. It is also facing huge compensation payments and other costs stemming from the 2011 Fukushima Daiichi accident. The seven-unit Kashiwazaki-Kariwa complex was one of the world's largest NPPs with a combined output capacity of 8, 210MWe when it was fully operational.
Although Kashiwazaki-Kariwa was unaffected by the March 2011 earthquake and tsunami all seven of the plant’s reactors had been offline for two to three years following the earlier 2007 Niigata-Chuetsu earthquake, which caused damage to the site. Work has since been carried out to improve the plant's earthquake resistance. Tepco applied for NRA approval of its design and construction plan for Kashiwazaki-Kariwa units 6&7 (1356 MWe advanced boiling water reactors) in September 2013.
Tepco submitted information on safety upgrades across the site and at those units, which began commercial operation in 1996 and 1997 and were the first Japanese boiling water reactors to be considered for restart. NRA cleared safety screenings for the two units in 2017 paving the way for the resumption of operations. However, security breaches and delays in completing safety upgrades caused delays.
The Kashiwazaki-Kariwa plant was found to be vulnerable to unauthorised entry at multiple locations because of defective intruder detection systems and backups, with security flaws discovered since January 2021, according to NRA. In April 2021, NRA prohibited the transportation or loading of reactor fuel stored at the plant due to insufficient counterterrorism measures, ordering the utility to take corrective action. "We want (Tepco) to take this as a starting line and we will request for continuous improvement" as stipulated in a report on inspections, NRA Chairman Shinsuke Yamanaka said. NRA has now confirmed that measures to prevent the leakage of radioactive materials had been enhanced through an additional 4,268 hours of inspections.
NRA made the decision based on an assumption that continued improvements can be expected at the plants in terms of both hardware and policy. In terms of policy, Tepco has established a Physical Protection Monitoring Office at the plant under the direct supervision of the company’s President Tomoaki Kobayakawa. This will enable him to be instrumental in improving on-site problems, rather than reacting on an ad hoc basis. Tepco has also provided more opportunities to communicate with employees of subcontractors to create an atmosphere in which they can point out problems frankly. As to hardware. switching to equipment more suitable for natural conditions, such as heavy snowfall, has helped to greatly reduce technical problems.
In response to NRA’s decision, Kobayakawa said, “We will keep in mind that we have only returned to the starting line and continue our efforts to improve.”
Niigata Governor Hanazumi is expected to ascertain residents’ opinion on the plant’s restart through discussions in the prefectural assembly, a referendum and a gubernatorial re-election. “An election of course is an option,” he told reporters. However, some local residents oppose such a step. “By setting a precedent of holding a gubernatorial re-election to question the restart – which is a national policy – other local governments may be forced to follow suit,” a senior official of the Kashiwazaki Chamber of Commerce & Industry said. Tohoku University Associate Prof. Kazunori Kawamura said it was a complex issue and “a gubernatorial election or referendum may not be able to successfully mirror public opinion”.
Meanwhile, the Kishida administration, which is seeking to accelerate the restart of NPPs, plans to hold briefings for local municipalities from early next year to seek their understanding. The administration hopes to win their consent by offering financial support such as a grant of up to JPY1bn ($7.02m).
According to Tepco, restart of Kashiwazaki-Kariwa 6&7 will reduce its fuel costs for thermal power generation, resulting in savings of JPY120bn a year. Currently, Tepco’s electricity rates are 20% higher than those of Kansai Electric Power Co and others. “I will take the lead in fulfilling my accountability,” Kobayakawa said.
Economy, Trade & Industry Minister Ken Saito, after a meeting with Kobayakawa, noted: “It is extremely important for Tepco to regain the trust it has lost and become an organisation that can improve on its own.” Saito asked Tepco to report on its measures to restore trust early next year.
Image: Tepco’s Kashiwazaki-Kariwa NPP in northern Japan's Niigata prefecture has been approved for restart by the Nuclear Regulation Authority more than two years after an order was issued for improvement of counterterrorism measures
