Tokyo Electric Power Co. has announced that it will decommission all four reactors at its Fukushima No. 2 nuclear power plant.

The decision indicates the landscape of nuclear energy in Japan is entering an age of mass decommissioning.

TEPCO plans to work concurrently to scrap a total of 10 nuclear reactors, including all six at the Fukushima No. 1 nuclear power plant, the site of the 2011 disaster. The task will be almost unparalleled and unprecedented in the world in terms of its scale.

TEPCO should fulfill its momentous duties in undertaking the task to help rebuild disaster-stricken communities of Fukushima Prefecture.

It took TEPCO an entire year to make the latest decision after the utility said last year it would consider the decommissioning option. That is enough evidence there are high barriers to be surmounted.

One difficulty consists in ensuring the availability of workers.

A staff of 3,600 is currently working to scrap the Fukushima No. 1 nuclear plant, where four reactors went crippled. Work to grasp the full picture of the reactor interiors, where nuclear fuel melted down, remains in a trial-and-error stage and is facing extremely rough going.

The latest decision means the Fukushima No. 2 plant, a logistic support base for those efforts, will itself be an additional site of decommissioning work.

TEPCO officials said they have largely figured out how the work will be done. We are left to wonder, however, how they plan to get all the necessary, highly skilled workers.

The task should be undertaken cautiously and steadily so there will be no accidents.

While it is believed it takes about 30 years to decommission a typical nuclear reactor, TEPCO officials said it will likely take more than 40 years to scrap all the reactors at the Fukushima No. 2 plant because the work cannot be done on all four reactors there in one continuous period.

That is about the same span of time that someone spends working for a company from entrance as a new hire through retirement age. The efforts will straddle generations.

TEPCO will be required to keep its staff highly motivated and to overcome any difficulties responsibly during all that time.

While the scrapping work will only start after specific plans for it have been approved by the government’s Nuclear Regulation Authority, solutions have yet to be decided for many anticipated problems.

The four reactors of the Fukushima No. 2 plant contain about 10,000 spent nuclear fuel assemblies. TEPCO plans to have them stored temporarily on the grounds of the nuclear plant before having them taken out of Fukushima Prefecture.

But where exactly they will be taken “will be studied in the years to come,” said Tomoaki Kobayakawa, president of TEPCO Holdings Inc.

Some rules remain to be determined for the disposal of radioactive waste, of which more than 50,000 tons are expected to be produced.

Decommissioning of nuclear reactors is a challenge that faces all major electric utilities.

Decisions have been made to scrap 21 nuclear reactors in the wake of the Fukushima disaster, and more are expected over time.

The question of what to do with spent fuel and radioactive waste should not be put on the back burner. The government should work to solve it.

Rising costs due to tightened safety measures have given a push to utilities’ decisions to scrap their reactors. Only nine reactors have so far been brought back online following the Fukushima disaster.

Plans to build new nuclear plants and reactors are making little progress. As a matter of reality, nuclear energy is losing the status of a mainstay power source.

That notwithstanding, utilities still stick to their old stance of continued reliance on nuclear power, saying they want to utilize what they have.

TEPCO is no exception. The owner of seven reactors at the Kashiwazaki-Kariwa nuclear plant in Niigata Prefecture is hoping to reactivate the No. 6 and No. 7 reactors there for starters.

Major utilities, especially TEPCO, are required to face up to the tough reality and look at what lies beyond the age of mass decommissioning. They bear the social responsibility to assign ample human and financial resources for renewable energy sources, which will be a major pillar of power supply for the next generation, among other areas.

--The Asahi Shimbun, July 28