Kashiwazaki-Kariwa units pass safety inspections

Units 6 and 7 of Tokyo Electric Power Company's Kashiwazaki-Kariwa nuclear power plant in Niigata Prefecture meet Japan's new regulatory standards, the Nuclear Regulation Authority announced today. They are the first of the country's boiling water reactors determined to meet the standards.

Units 6 and 7 of Tokyo Electric Power Company's (Tepco's) Kashiwazaki-Kariwa nuclear power plant in Niigata Prefecture meet Japan's new regulatory standards, the Nuclear Regulation Authority (NRA) announced today. They are the first of the country's boiling water reactors (BWRs) determined to meet the standards.

Kashiwazaki-Kariwa units 6 and 7 (Image: Tepco)

Under Japan's reactor restart process, plant operators are required to apply to the NRA for: permission to make changes to the reactor installation; approval of its construction plan to strengthen the plant; and, final safety inspections to ensure the unit meets new safety requirements. Operators are required to add certain safety-enhancing equipment within five years of receiving the NRA's approval of a reactor engineering work programme.

Tepco filed for safety assessments of Kashiwazaki-Kariwa 6 and 7 in September 2013. The units - 1356 MWe Advanced Boiling Water Reactor units built in the late 1990s - were the first Japanese BWRs to be put forward for restart.

The NRA approved a draft document on 4 October this year that concluded the units meet new safety standards that came into force in July 2013 following the accident at Tepco's Fukushima Daiichi plant in March 2011. That draft document was then released for public comment. The NRA today announced its official approval of the review reports, thereby approving revision of the reactor installation permit of the two units, the first stage in the restart process.

Tepco said: "We would like to express our heartfelt appreciation to the members of the Nuclear Regulation Authority, and all those involved with inspections, for all their hard work during the four-plus years since we applied for permission. Going forward, Tepco will continue to carefully and earnestly take all actions required by inspections relating to our applications for revision for construction permit and safety regulations."

Kashiwazaki-Kariwa was unaffected by the March 2011 earthquake and tsunami which damaged the Fukushima Daiichi plant, although the plant's reactors were previously all offline for up to three years following the 2007 Niigata-Chuetsu earthquake, which caused damage to the site but did not damage the reactors themselves. While the units were offline, work was carried out to improve the plant's earthquake resistance.

Although it has worked on the other units at the Kashiwazaki-Kariwa site, Tepco is concentrating its resources on units 6 and 7 while it deals with the clean-up at Fukushima Daiichi. Restarting those two units - which have been offline for periodic inspections since March 2012 and August 2011, respectively - would increase the company's earnings by an estimated JPY100 billion ($883 million) per year.

Tepco said today, "As we have mentioned during NRA meetings, Tepco will meet our responsibilities to help Fukushima recover, decommission the Fukushima Daiichi plant and provide compensation, whilst striving to improve nuclear safety and further improve the safety and reliability of the Kashiwazaki-Kariwa plant. In doing this, Tepco will succeed in managing Kashiwazaki-Kariwa whilst prioritising the local community and offer our complete cooperation to the three investigations being conducted by Niigata Prefecture."

Niigata Prefecture Governor Ryuichi Yoneyama has said he will not discuss their restart until Tepco has completed a review into the accident at Fukushima Daiichi, a process expected to take up to four years. The mayor of Kashiwazaki, Masahiro Sakurai, has also called for at least one of the plant's seven reactors to be decommissioned as a precondition to the restart of units 6 and 7.

Of Japan's 42 operable reactors, five have so far cleared inspections confirming they meet the new regulatory safety standards and have resumed operation. These are: Kyushu's Sendai units 1 and 2; Shikoku's Ikata unit 3; and Kansai's Takahama units 3 and 4. Another 19 reactors have applied to restart.

Researched and written
by World Nuclear News