Japan's nuclear watchdog on Wednesday decided that a reactor in Fukui Prefecture failed to pass its restart safety review, marking the first such case since the regulatory body's founding after the 2011 Fukushima nuclear crisis.
The No. 2 reactor at the Tsuruga plant in central Japan, operated by Japan Atomic Power Co, fell short of the safety requirements due to a possible active fault underneath the offline unit. The Nuclear Regulation Authority plans to seek public comments on its assessment report before making its decision official possibly in the fall.
In quake-prone Japan, building reactors or other important safety facilities directly above active faults is prohibited.
Japan Atomic Power first applied for the safety screening with the hope of restarting the reactor in November 2015.
But a safety review team of the NRA concluded in July this year it could not rule out that an active fault located around 300 meters north of the reactor building could potentially stretch right beneath the facility.
The assessment process for the reactor had been rocky, with proceedings suspended twice after it was revealed that Japan Atomic Power had submitted documents that included inaccuracies and data rewritten without approval. It reapplied in August last year.
The Tsuruga nuclear plant is a two-unit complex, with the No. 1 reactor set to be scrapped.
The No. 2 reactor, which started commercial operations in February 1987, went offline in May 2011.
Japan revamped its regulatory setup by launching the NRA in 2012 and has also introduced a set of new safety requirements to reflect the lessons learned from the disaster at Tokyo Electric Power Company Holdings Inc's Fukushima Daiichi plant, triggered by a huge earthquake and tsunami in March 2011.
So far, 17 reactors among the 27 that have been put forward for safety screening nationwide have cleared the process.
