Japan's Nuclear Regulatory Authority (NRA) has approved the operational safety programme submitted by Tokyo Electric Power Company (Tepco) for its Kashiwazaki-Kariwa nuclear power plant in Niigata prefecture.
Earlier in October, NRA approved Tepco's plan for implementing additional safety upgrades at Kashiwazaki-Kariwa 7. Tepco plans to complete the work in December.
Tepco in 2013 submitted information on safety upgrades - including its operational safety programme at the nuclear plant and in particular for units 6&7 which it is seeking to restart. Kashiwazaki-Kariwa 6&7, both 1356MWe Advanced Boiling Water Reactors, were built in the late 1990s.
Although the seven-unit Kashiwazaki-Kariwa plant was unaffected by the March 2011 earthquake and tsunami, which destroyed Tepco's Fukushima Daiichi plant, all the reactors were previously all offline for two to three years after the 2007 Niigata-Chuetsu earthquake, which damaged the site but not the reactors. While the units were offline, work was carried out to improve seismic resistance.
In October 2017, the NRA approved a draft report confirming that Kashiwazaki-Kariwa 6&7 met the more stringent post-Fukushima safety standards. It listed safety measures that still needed to be implemented at the site, including seismic reinforcements and construction of a seawall, as well as measures to prevent a serious accident in the event of the loss of on-site power.
Kashiwazaki-Kariwa 6&7 are the first boiling water reactors (BWRs) to be put forward for restart in Japan. All the other units are pressurised water reactors. Under the new safety requirements, Japanese BWRs must be equipped with filtered venting systems.
Photo: Kashiwazaki-Kariwa Nuclear Power Plant (??? - Own work; CC BY-SA 4.0)