The Nuclear Regulation Authority has determined that the No. 2 reactor of the Tsuruga Nuclear Power Plant in Fukui Prefecture does not meet its safety standards. The decision will block efforts to restart the idled reactor.

Operator Japan Atomic Power Co. should make a decision to decommission the reactor given the grim fact it has been unable to meet the safety requirements to bring the unit back online in spite of the huge amount of time it has spent on the effort, while many other reactors have met the regulatory requirements.

At a July 26 review meeting, the nuclear safety watchdog concluded that the possibility of an active fault running directly beneath the containment building that houses the Tsuruga No. 2 reactor cannot be ruled out.

The stricter nuclear safety standards established after the catastrophic accident at the Fukushima No. 1 nuclear plant in 2011 categorically state that critical facilities such as nuclear reactors must not be located directly above an active fault, which is a fracture or a zone of fractures in the Earth’s crust where the movement of rocks can cause earthquakes. If ground surface displacement occurs around such vital facilities, it can cause significant damage, leading to a severe accident.

The NRA is expected to reject Japan Atomic Power’s application to restart the reactor, following the compilation of the review document.

Since the NRA’s establishment, 27 reactors have applied for permission to restart, and 17 have been recognized as meeting the new safety standards. If the application to reactivate the Tsuruga No. 2 unit is rejected, it will mark the first such action by the regulatory body.

A major nuclear accident would cause irreversible damage. Based on this lesson, regulatory decisions on the safety of reactors should err on the side of greater safety when in doubt.

The risk from an active fault directly below a critical nuclear facility is extremely high, and if its presence under the reactor cannot be denied, there is a compelling case for not allowing the operation of the reactor.

However, the NRA cannot force the decommissioning of nuclear reactors that do not meet the new safety standards. Japan Atomic Power plans to seek further reviews from the NRA after additional plant surveys to secure permission to restart the reactor.

Yet, nine years have already passed since the application to restart the Tsuruga No. 2 unit was submitted. The prolonged review process is due to the operator’s mishandling of the procedure.

There were more than 1,000 errors in the application documents. Tampering with geological data was also discovered.

These were serious issues that shook the foundation of the safety assessment, leading to the NRA’s decision to suspend the process.

Given the backlog of other nuclear plant reviews and the time the NRA has already devoted to this application, Japan Atomic Power must surely realize it is being unreasonable in pursuing the undertaking.

In the first place, the location of the Tsuruga nuclear plant is not suitable for a nuclear facility. Japan Atomic Power acknowledges that an active fault, known as “Urasoko Danso,” runs through the site.

Located on a peninsula, evacuation routes would be limited in the event of an earthquake causing a serious accident. We just witnessed how the Jan. 1 Noto Peninsula earthquake flattened many buildings and cut off roads at many locations, reaffirming the difficulty of sheltering indoors or evacuating when a major earthquake hits a peninsula.

Japan Atomic Power is a company that sells electricity generated from nuclear power to major electric utilities that are its shareholders.

But since the earthquake and tsunami disaster in 2011, it has been decided that two of the company’s four reactors need to be decommissioned. As the other two are not in operation, the company is forced to operate only on the “basic fees” paid by the electric power companies.

This cost is passed on to the public through higher electric bills. The major electric power companies have a responsibility to consider the future of Japan Atomic Power, including whether to continue or discontinue its operations.

--The Asahi Shimbun, July 27