Japan’s Nuclear Regulation Authority has decided that the No.2 reactor at the Tsuruga nuclear power plant in Fukui Prefecture failed to pass its restart safety review.
The decision marks the first time the regulatory body decided not to approve the restart of a nuclear power plant. The watchdog authority was established in 2012, a year after the 2011 nuclear accident at the Fukushima Daiichi power plant due to the earthquake and tsunami.
At a regular meeting on Wednesday, the NRA unanimously agreed on a draft assessment compiled by its secretariat. The document indicated that the No.2 reactor at the Tsuruga nuclear power plant did not meet regulatory standards due to a fault directly beneath the building.
The assessment of the offline unit began in 2015, focusing on whether the fault might move in the future.
The regulatory secretariat concluded in July that the possibility of the fault moving could not be ruled out. It therefore determined that the reactor does not meet the regulatory standards, which do not allow safety-critical facilities to be built over an active fault.
In response, the Japan Atomic Power Company, which operates the plant, requested additional surveys of the fault. But the NRA rejected the request after meeting with the company’s president earlier in August.
The NRA plans to make its decision official after hearing public comments on its assessment.
The Japan Atomic Power Company intends to apply for a fresh round of screening.
But the regulatory body says a reassessment of over 100 faults in and around the plant is a prerequisite. Therefore, it is unclear when the operator can submit its application.
Since the assessment started nine years ago, the review has undergone a rocky process.
In the year it began, an expert panel of the NRA pointed out that the fault under the reactor could move in the future, while the power company maintained that there was no possibility of that happening.
The screening process was repeatedly suspended after inaccuracies and unauthorized alterations were found one after another in the data contained in reports submitted by the plant operator.
In April last year, the NRA instructed the utility firm to amend and resubmit its report regarding the fault, with its chairman declaring that no further corrections would be accepted.
The operator resubmitted a revised application for the screening in August last year. But regulatory officials said the power company’s explanations about the fault lack scientific evidence.