The nation’s oldest nuclear reactor was brought back online at the Takahama nuclear power plant in Fukui Prefecture on July 28 for the first time in 12 years.

Operated by Kansai Electric Power Co., the No. 1 reactor at the Takahama plant first went into service in 1974. 

The restart followed an extension of the reactor service period, which is set at 40 years in principle.

It left serious problems unaddressed, including the effectiveness of current evacuation plans in an emergency and how spent nuclear fuel from the reactor will be handled.

We cannot help but harbor doubts and fears about the situation. 

The Takahama No. 1 reactor was undergoing regular maintenance and safety inspections when the 2011 earthquake and tsunami disaster triggered a triple meltdown at the Fukushima No. 1 nuclear power plant and had remained offline since then.

Lessons from the disaster at the Fukushima facility, which is operated by Tokyo Electric Power Co., led the authorities to set the service life of all nuclear reactors at 40 years in principle, with an exceptional provision that the service period may be extended for a maximum of 20 years just once.

That provision was applied to the Takahama No. 1 reactor. The Nuclear Regulation Authority approved an extension of the reactor’s service life in 2016 following a screening process.

The nuclear power plant built half a century ago, however, has an old design. Concerns have also been raised about the deterioration of reactor components such as the state of the cables and concrete used in its construction as the deterioration progressed while the reactor remained offline.

Let us recall the 40-year rule was intended not only to make Japan less dependent on atomic energy but also to reduce risks arising from these and other forms of age-related degradation.

The central government, however, has emasculated that rule. Tokyo has not only applied the exceptional 20-year extension clause to one reactor after another but also amended laws during the last Diet session to allow nuclear reactors to operate for more than 60 years.

The central government has effectively ditched the lessons of the Fukushima disaster.

The reactor restart, against the backdrop of a revival of nuclear power generation, has presented, in addition to the aging issue, a variety of conundrums that have yet to be solved.

The coastal area along Wakasa Bay, where the Takahama plant is located, is known as the “main thoroughfare” of nuclear plants, as the area in Fukui Prefecture is also home to Kansai Electric’s Oi and Mihama nuclear facilities and Japan Atomic Power Co.’s Tsuruga nuclear plant.

That makes simulations of, and response to, possible emergencies quite a complicated affair. The area’s residents harbor deep-rooted concerns about whether they would be able to take refuge as planned, given the topographical limitations to available evacuation routes.

There are also issues related to the “aftermath” of nuclear power generation.

Kansai Electric promised the Fukui prefectural government it would acquire a land plot outside the prefecture to build an interim storage facility for spent nuclear fuel, which continues to accumulate at the three nuclear plants it operates in the prefecture.

The utility had set a final deadline for doing so at the end of this year, but no prospect is in sight for finding a candidate site.

Last month, Kansai Electric said it will be shipping part of the spent nuclear fuel from the Takahama plant to France, which operates a reprocessing plant, and argued that measure means the utility “has fulfilled its promise.”

Kansai Electric’s sophistry, however, leaves us dumbfounded. The shipment accounts for only 5 percent of the total amount being stored at the three nuclear plants.

Residents of Fukui Prefecture were quite rightly angered by the utility’s argument.

Moreover, Kansai Electric is planning to restart the Takahama plant’s No. 2 reactor as early as September. It has also applied for a 20-year service life extension for the Takahama plant’s No. 3 and No. 4 reactors.

The utility’s attitude can only be described as irresponsible.

The structure behind these problems is common to all of Japan’s nuclear plants and reactors.

One of the structural factors is a deep impasse that persists when it comes to the country’s nuclear fuel recycling program, which would involve reprocessing of spent nuclear fuel.

In addition, no prospect is in sight for finding a site for the final disposal of high-level radioactive waste that is left behind in the end.

The power industry and the central government should squarely face these realities, as epitomized by the situation at the Takahama nuclear plant.

--The Asahi Shimbun, July 31