Two nuclear reactors on the Sea of Japan coast have become the first run by the operator of the crippled Fukushima power plant to formally clear the stricter government safety standards imposed after the 2011 crisis.
The Nuclear Regulation Authority endorsed Wednesday safety measures for the No. 6 and 7 reactors at Kashiwazaki-Kariwa power station in Niigata Prefecture, paving the way for their restart by Tokyo Electric Power Company Holdings Inc., known as Tepco.
The two reactors are boiling-water reactors, the same as those that suffered meltdowns in the Fukushima crisis caused by the massive earthquake and tsunami in March 2011. No such reactor types had previously cleared Japan's tougher safety standards since the disaster, partly as they are required to conduct major refurbishment for added safety.
The NRA's endorsement of the two units gives impetus to the Japanese government's push to restart idled nuclear power plants that were taken offline after the world's worst nuclear disaster since Chernobyl.
In addition to assessing technical requirements, the review by the NRA focused on whether Tepco is qualified to operate a nuclear power plant as it struggles with the scrapping of the Fukushima Daiichi complex -- an effort expected to take until around 2051 -- and in dealing with contaminated water around the crippled plant where radiation levels remain high.
Tepco, facing huge compensation payments and other costs stemming from the Fukushima crisis, has been keen to resume operation of its reactors to reduce dependence on costly fossil fuel imports for non-nuclear thermal power generation.
However, the process of restarting the two reactors straddling the municipalities of Kashiwazaki and Kariwa in Niigata could still require at least several more years as local governments need to give their consent to resumption.
Among them, Niigata Gov. Ryuichi Yoneyama has said it will take "at least three to four years" before deciding whether to give his approval to bringing them back online, citing the need to assess the causes of the accident at the Fukushima Daiichi nuclear complex.
The two reactors are the newest among the seven units at the Kashiwazaki-Kariwa plant. The complex is one of the world's largest nuclear power plants, with a combined output capacity of 8.2 million kilowatts.
In a move not seen in the screening processes for other utilities, Tepco agreed to a request from the regulator to provide a pledge to carry through the scrapping of the Fukushima complex, leading the regulator to soften its position.
Tepco filed for safety assessments of the two reactors in September 2013.
