Japan’s Nuclear Regulation Authority (NRA) announced on 27 December that units 6&7 of Tokyo Electric Power Company's Kashiwazaki-Kariwa nuclear plant in Niigata Prefecture meet Japan's new regulatory standards. They are the first boiling water reactors (BWRs) to receive NRA approval. All the other reactors approved for restart have been pressurised water reactors (PWRs).
Tepco filed for safety assessments of the 1356MWe Advanced Boiling Water Reactor units in September 2013. NRA approved a draft document in October which said the units met the new post-Fukushima safety standards. That document was released for public comment and NRA has now approved the revision of the reactor installation permit.
Kashiwazaki-Kariwa was unaffected by the March 2011 earthquake and tsunami which damaged the Fukushima Daiichi plant, but the site had previously been damaged during the 2007 Niigata-Chuetsu earthquake causing the reactors to be taken offline. Local opposition to restart of the plant remains strong. Niigata Prefecture Governor Ryuichi Yoneyama has said he will not discuss restart of the units until Tepco has completed a review into the accident at Fukushima Daiichi, which is 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 Kashiwazaki-Kariwa 6&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 1&2; Shikoku's Ikata 3; and Kansai's Takahama 3&4. Another 19 reactors have applied to restart.
In mid-December, Kansai Electric Power Company applied to NRA for pre-service inspections of Mihama 3 in Fukui Prefecture. Kansai submitted its restart application for Mihama 3 in March 2015. The NRA approved the utility's basic design and detailed design for the unit in October 2016 and approved Kansai's safety programme for Mihama 3, a 780MWe PWR, the following month. Kansai expects all inspections to be completed by late March 2020.
Photo: Kashiwazaki-Kariwa nuclear plant (Photo: IAEA)