The 40-year lifespan for nuclear reactors, established after the catastrophic accident at the Fukushima No. 1 nuclear power plant in 2011, is now in danger of being watered down to irrelevance.

The rule requires the decommissioning of aging reactors, starting with the oldest, for a gradual, carefully controlled process of phasing out nuclear power generation in this country.

The Nuclear Regulation Authority (NRA) on April 20 formally decided that the No. 1 and No. 2 reactors at Kansai Electric Power Co.’s Takahama nuclear power plant in Fukui Prefecture, which have been in service for over 40 years, meet new nuclear safety standards introduced after the devastating 2011 accident.

This is the first license renewal for a reactor that has been in operation for more than four decades under the new standards.

If they pass the remaining regulatory inspections concerning technical details by the July deadline, the reactors will likely continue to generate electricity for two more decades.

The 40-year lifespan provision was introduced through a revision to the law after the Fukushima disaster.

Just one service life extension of up to 20 years is allowed, but only as an “extremely exceptional” measure.

This exception was made to avoid a shortage of electricity. But concerns about any serious power crunch have virtually dissipated thanks to a marked rise in levels of power and energy conservation in society.

The NRA’s formal decision to extend the life of the two aging reactors came amid a series of earthquakes rocking central Kyushu around Kumamoto Prefecture which have been described by the Japan Meteorological Agency as “a deviation from the rules extracted from past experiences.”

Many Japanese are concerned that the quakes could affect Kyushu Electric Power’s Sendai nuclear plant in neighboring Kagoshima Prefecture. The NRA’s decision to grant an exception to the rule so quickly could have the effect of relaxing the safety standards and deepening public distrust of the government’s nuclear regulation.

The Abe administration is leaving all licensing decisions on individual reactors entirely to the NRA. But it has mapped out a long-term energy supply plan based on the assumption that the service life of reactors will be extended.

Prime Minister Shinzo Abe, who repeatedly pledged to lower Japan’s dependence on nuclear power as much as possible, has been changing his stance little by little without announcing any clear policy shift.

The NRA’s mission is to enhance the safety of nuclear plants from a scientific viewpoint.

But the way the nuclear watchdog assessed the safety of the reactors at the Takahama plant has raised questions about its appropriateness. The NRA has, for instance, allowed Kansai Electric Power to delay required quake resistance tests.

If it has scheduled its assessment work in a way to ensure that the July deadline will be met, the agency has got its priorities completely wrong.

A troubling situation is now emerging where decisions on whether to decommission specific reactors are effectively left to the utilities that operate them. As a result, these decisions are being based primarily on whether extending the life of the reactors will pay.

Operating many nuclear reactors in Japan, a small country with a large population that is highly prone to earthquakes and other natural disasters, inevitably entails a large risk.

This grim reality was the starting point for the reform of the nuclear power policy prompted by the Fukushima accident.

If the government sticks to the policy of maintaining nuclear power generation, the burden on society, including the costs of disposing of nuclear waste, could increase over the long term.

There is a clear global trend toward raising energy self-sufficiency through efforts to develop renewable energy sources.

A transition period may be necessary. But the only policy that makes sense is to shut down reactors steadily over a period of years.

The 40-year rule is one of the key principles of this policy. The government should remember this fact.

--The Asahi Shimbun, April 21