Iit was a project that promised the sun. Researchers will use the world’s most advanced technology to design a machine that can generate nuclear fusion, the process that powers the stars – and thus create a source of cheap, non-polluting power.
This was initially the aim of the International Thermonuclear Experimental Reactor (Iter) which 35 countries – including European states, China, Russia and the US – agreed to build at Saint-Paul-lez-Durance in the south of France against a start-up cost of $6 billion. Work began in 2010, with a commitment to have energy-producing reactions by 2020.
Then reality set in. Cost overruns, Covid, corrosion of key parts, last-minute redesigns and confrontations with nuclear safety officials have caused delays that mean Iter won’t be ready for another decade, it has just been announced. Worse, energy-producing fusion reactions won’t be generated until 2039, while Iter’s budget – already up to $20 billion – will increase by a further $5 billion.
Other estimates suggest that the final price tag could rise well above this figure, making Iter “the most delayed and cost-inflated science project in history,” the journal Scientific American warned. In turn, the journal Science simply stated that Iter is now in “big trouble”, while Earth noted that the project was “plagued by a series of delays, cost overruns and management issues”.
Dozens of private companies are now threatening to create fusion reactors on a shorter timescale, scientists warn. This includes Tokamak Energy in Oxford and Commonwealth Fusion Systems in the US.
“The problem is that Iter has been running for so long, and has had so many delays, that the rest of the world has moved on,” said fusion expert Robbie Scott of the UK Science and Technology Facilities Council. “A host of new technologies have emerged since Iter was planned. This left the project with real problems.”
A question mark now hangs over one of the world’s most ambitious technological projects in its global effort to harness the process that powers the stars. It involves forcing the nuclei of two light atoms to combine to form a single heavier nucleus, releasing massive amounts of energy. It is nuclear fusionand it only occurs at colossally high temperatures.
To create such heat, a doughnut-shaped reactor, called a tokamak, would use magnetic fields to contain a plasma of hydrogen nuclei that would 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 large amount of excess energy.
It is extremely difficult to contain plasma at such high temperatures. “It was originally planned to run the tokamak reactor with protective beryllium, but it was very difficult. It is toxic and eventually it was decided to replace it with tungsten,” said David Armstrong, professor of materials science and engineering at Oxford University. “It was a major design change taken very late in the day.”
Then large parts of the Korean-made tokamak were found not to fit together properly, while threats that there could be leaks of radioactive materials led French nuclear regulators to halt the plant’s construction. More delays in construction were announced as problems piled up.
Then came Covid. “The pandemic has closed factories that supply components, reduced the associated workforce and caused impacts – such as delays in shipping and challenges to carry out quality control inspections,” admitted Iter’s director general, Pietro Barabaschi.
So Iter put back its completion again – until the next decade. At the same time, researchers using other approaches to fusion have made breakthroughs. In 2022, the US National Ignition Facility in California said it used lasers to superheat deuterium and tritium and fuse them together to create helium and excess energy – a goal of Iter.
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Other merger projects claim that they may also break ground soon. “In the last 10 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 probably overpromising,” said Brian Appelbe, a physics research fellow at Imperial College London.
It remains to be seen whether Iter will survive these crises and its backers will continue to fund it – although most scientists working through the Observer argued that it still has promising work to do.
An example is the research into ways to generate tritium, the rare hydrogen isotope essential for fusion reactors. It can be made at a fusion reactor site by using the neutrons it generates to bombard samples of lithium, a process that makes helium and tritium. “It’s a valuable experiment in its own right,” Appelbe said.
Iter, for its part, denies that it is “in deep trouble” and rejects the idea that it is a record-breaking science project for cost overruns and delays. Just look at the International Space Station or for that matter the UK’s HS2 rail link, a spokesman said.
Others point out that fusion power’s limited carbon emissions will boost the fight against climate change. “However, fusion will come too late to help us reduce carbon emissions in the short term,” says Aneeqa Khan, a research fellow in nuclear fusion 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 low – and this will become crucial in the fight against climate change.”
