OSAKA - Japan is facing renewed questions over how to secure electricity while dealing with mounting nuclear waste, as power demand is expected to rise with the spread of generative AI and the government considers replacing as many as five nuclear reactors by the 2040s.
The Ministry of Economy, Trade and Industry presented a new proposal on June 5 saying Japan may need to replace up to five reactors by the 2040s and as many as 14 by the 2050s. The government says rising electricity demand, including from artificial intelligence, is forcing Japan to look again at nuclear power. But the final destination for the growing volume of spent nuclear fuel and radioactive waste remains undecided.
The issue was also taken up in this year’s nuclear energy white paper, compiled in June, which focused on the nuclear fuel cycle. The fuel cycle refers to the process of reprocessing spent fuel from nuclear power plants so that it can be used again as fuel, while disposing of material that cannot be reused. The white paper said the nuclear fuel cycle remains only partly realized and that public understanding of the issue cannot be described as high.
One country already deeply involved in the nuclear fuel cycle is France, a major nuclear power with a population of about 69 million and 57 reactors, one of the highest ratios in the world relative to population. Nuclear power accounts for more than 65% of France’s domestic electricity generation.
The first site visited was the Flamanville Nuclear Power Plant in Normandy, about five hours by car from Paris on the Cotentin Peninsula. Operated by state-owned Electricite de France, the plant’s No. 3 reactor began full-scale operations in December last year.
The No. 3 unit is a new EPR reactor. Like the advanced light-water reactors Japan aims to develop, it incorporates lessons from past nuclear accidents, with safety as a central feature. The plant is equipped with a core catcher designed to receive and contain molten nuclear fuel in the event of a meltdown. Its containment vessel and other facilities are covered by double concrete walls designed to withstand the impact of an aircraft crash caused by terrorism.
The No. 3 reactor can supply electricity to 2 million households. Construction began in 2007 and cost 13.2 billion euros, equivalent to about 2.4 trillion yen. France plans to build six more reactors and is also considering construction of another eight.
At the heart of the nuclear fuel cycle is reprocessing, which allows spent fuel used in power generation to be used again. In Japan, a reprocessing plant in Rokkasho, Aomori Prefecture, was originally scheduled for completion in 1997, but the project has been delayed 27 times.
France’s La Hague reprocessing plant has accepted spent fuel from Japan. Located about 15 kilometers north of the Flamanville plant, it receives spent fuel from nuclear power plants around the world in transport containers.
The fuel is removed behind thick glass. Although radiation is blocked by concrete walls 1.2 meters thick, radiation levels inside are extremely high, and no one has entered the area since operations began in 1986. Even maintenance work, such as replacing equipment, is carried out entirely by remote operation from outside.
The removed spent fuel is cooled and stored in pools 9 meters deep. More than 10,000 tons of spent fuel are held there. After a certain cooling period, reprocessing is carried out, recovering about 96% of the material as energy that can be used again for power generation.
The remaining 4%, which cannot be reused, is sealed in stable vitrified form inside special containers. This is high-level radioactive waste, commonly known as nuclear waste. The containers are stored for long periods underground in a facility designed specifically for that purpose.
Because Japan’s reprocessing facility remains incomplete, the country cannot reprocess spent fuel domestically. It has also yet to decide where to build a final disposal site for nuclear waste.
France, by contrast, is moving ahead with plans for final disposal. About 230 kilometers east of Paris, access was granted to the Bure Underground Research Laboratory. An elevator takes about five minutes to descend 500 meters below ground.
A network of long underground tunnels stretches for 2.5 kilometers in multiple directions. A final disposal facility is planned nearby, and the laboratory is being used to test whether nuclear waste and other radioactive materials can be disposed of underground.
About 30 experiments are being conducted at the site. Steel containers designed to hold nuclear waste are being tested, and the plan for the final disposal facility calls for robots to push the containers into underground tunnels, where the waste will be managed deep below the surface.
The surrounding area is made up of clay rock that allows little water to pass through, making it suitable for confining radioactive waste. France plans to begin placing radioactive waste in the final disposal facility from 2050.
Japan has now set out a new direction for replacing aging reactors. Kansai Electric Power is among the utilities moving first. The company has decided to decommission the No. 1 and No. 2 reactors at the Mihama Nuclear Power Plant in Fukui Prefecture and began geological surveys in November last year as part of preparations for possible replacement. Kansai Electric says it will continue surveys and analysis before deciding whether to install a new reactor.
Asked about realizing the nuclear fuel cycle, Kansai Electric President Nozomu Mori said the process remains incomplete at this stage but must be achieved as soon as possible. "France is a little ahead in realizing it," Mori said. "With a certain level of involvement from the national government, we will also fulfill our role and move forward."
With electricity demand expected to increase as generative AI spreads, securing power for daily life has become an issue that everyone must face. The question now is what Japan will leave, and what it wants to leave, for future generations.
Source: Television OSAKA NEWS
