HomeTech Is the dream of nuclear fusion dead? Why is the international experimental reactor in serious trouble?

Is the dream of nuclear fusion dead? Why is the international experimental reactor in serious trouble?

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Is the dream of nuclear fusion dead? Why is the international experimental reactor in serious trouble?

YoIt was a project that promised the Sun. Researchers would use the world’s most advanced technology to design a machine capable of generating atomic fusion, the process that powers stars, and thus create a cheap, non-polluting source of energy.

That was the initial aim of the International Thermonuclear Experimental Reactor (ITER), which 35 countries – including European states, China, Russia and the United States – agreed to build in Saint-Paul-lez-Durance, in the south of France, at an initial cost of 6 billion dollars. Work began in 2010, with the commitment that reactions that would produce energy would be available by 2020.

But reality has taken over. Cost overruns, Covid, corrosion of key parts, last-minute redesigns and clashes with nuclear safety officials have led to delays that mean Iter will not be ready for another decade, it has just been announced. Worse still, fusion reactions that produce energy will not be generated until 2039, while Iter’s budget, which has already ballooned to $20 billion, is set to increase by another $5 billion.

Other estimates suggest the final price tag could far exceed this figure, making Iter “the most over-expensive and delayed scientific project in history,” the magazine said. American scientist has warned. For its part, the magazine Science has simply stated that Iter is now in “big trouble,” while Nature He said the project had been “plagued by a series of delays, cost overruns and management problems.”

Dozens of private companies are threatening to build fusion reactors within a shorter timeframe, scientists warn. These include Oxford-based Tokamak Energy and US-based Commonwealth Fusion Systems.

“The problem is that Iter has been going on for so long and has suffered so many delays that the rest of the world has moved on,” says fusion expert Robbie Scott of the UK’s Science and Technology Facilities Council. “Since Iter was planned, a whole host of new technologies have emerged, which has left the project in real trouble.”

The Iter plant takes shape in Saint-Paul-lez-Durance, in the south of France, in June. Photo: EJF Riche/Iter Organization

A question mark now hangs over one of the world’s most ambitious technological projects as it attempts to harness the process that powers stars. It involves the nuclei of two light atoms being forced to combine to form a single, heavier nucleus, while releasing vast amounts of energy. This is called nuclear fusion, and it only occurs at colossal temperatures.

To generate that heat, a doughnut-shaped reactor called a tokamak will use magnetic fields to contain a plasma of hydrogen nuclei that will then be bombarded by particle beams and microwaves. When temperatures reach millions of degrees Celsius, the mixture of two hydrogen isotopes — deuterium and tritium — will fuse to form helium, neutrons and a huge amount of excess energy.

Containing plasma at such high temperatures is exceptionally difficult. “It was originally planned to coat the tokamak reactor with protective beryllium, but that turned out to be very difficult. It is toxic and it was eventually decided to replace it with tungsten,” said David Armstrong, professor of materials science and engineering at the University of Oxford. “That was a major design change that was made very late.”

Large sections of Korean-made tokamak were then found to be improperly fitted together, while threats of potential leaks of radioactive materials led French nuclear regulators to suspend construction of the plant. Further construction delays were announced as the problems mounted.

Then came the Covid-19 pandemic. “The pandemic has forced factories supplying components to close, reduced the associated workforce and caused consequences such as delays in shipments and difficulties in carrying out quality control inspections,” acknowledged Iter’s general manager, Pietro Barabaschi.

As a result, Iter has once again postponed its completion until the next decade. At the same time, researchers using other fusion methods have made progress. In 2022, the US National Ignition Facility in California said it had used lasers to superheat deuterium and tritium and fuse them to create helium and surplus energy, a goal of Iter.

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Other fusion projects also claim they could soon make major breakthroughs. “Over the past ten years, there has been a huge growth in private fusion companies promising to do things differently – faster and cheaper – than Iter. Although, to be fair, some are likely to overpromise,” said Brian Appelbe, a physics researcher at Imperial College London.

It remains to be seen whether Iter will survive these crises and its sponsors will continue to fund it, although most of the scientists contacted by the Observer He argued that he still has promising work to do.

One example is research into ways to generate tritium, the rare isotope of hydrogen that is essential for fusion reactors. This can be achieved in a fusion reactor by using the neutrons it generates to bombard samples of lithium, a process that produces helium and tritium. “It’s a worthwhile experiment in itself,” Appelbe said.

For its part, ITER denies that it is “in serious trouble” and rejects the idea that it is a scientific project that will break records in terms of cost overruns and delays. Just look at the International Space Station or, for that matter, the British rail link HS2, said a spokesman.

Others point out that fusion power’s limited carbon emissions would boost the fight against climate change. “However, fusion will come too late to help us reduce carbon emissions in the near term,” said Aneeqa Khan, a nuclear fusion researcher at the University of Manchester. “Only if fusion power plants produce significant amounts of electricity later in the century will they help keep our carbon emissions down, and that will be crucial in the fight against climate change.”

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