The ITER fusion reactor currently being built in France will not achieve first operation until 2034 – almost a decade later than previously planned and some 50 years after the project was first conceived in 1985. The decision by ITER management to take another 10 years constructing the machine means that the first experiments using “burning” fusion fuel – a mixture of deuterium and tritium (D–T) – will now have to wait until 2039. The new “baseline” was agreed as a “working reference” by ITER’s governing council and will be further examined before a meeting in November.
ITER is an experimental fusion reactor that is currently being built in Cadarache, France, about 70 km north-west of Marseille. Expected to cost tens of billions of euros, it is a collaboration between China, Europe, India, Japan, Korea, Russia and the US. Its main aim is to generate about 500 MW of fusion power over 400 seconds using a plasma heating of 50 MW, a power gain of 10. The reactor would also test a “steady state” operation under a power gain of five.
Yet since its conception in the 1980s (see timeline below), ITER has been beset with cost hikes and delays. In 2016, a baseline was presented in which the first deuterium plasma would be delayed until 2025.
This first plasma, however, would have been a brief machine test before further assembly, such as adding a divertor heat-exhaust system and further shielding. “The first plasma [in 2025] was rather symbolic,” claims ITER director-general Pietro Barabaschi, who took up the position in October 2022 following the death of former ITER director general Bernard Bigot.
ITER would only have reached full plasma current in 2032 with the first D–T reaction waiting until 2035 after the installation of additional components.
A new ‘baseline’
Barabaschi notes that since 2020 it was “clear” that the 2025 “first plasma” date was no longer achievable. This was due to several reasons, one of which was the COVID-19 pandemic, which led to supply-chain and quality-control delays.
Manufacturing issues also emerged such as the discovery of cracks in the water pipes that cool the thermal shields. In early 2022 the French Nuclear Safety Authority briefly halted assembly due to concerns over radiological shielding.
Officials then began working on a more realistic timeline for construction to allow for more testing of certain components such as the huge D-shaped toroidal-field coils that will be used to confine the plasma.
The plan now is to start operation in 2034 with a deuterium-only plasma but with more systems in place as compared to the previous “first plasma” baseline of 2025. Research on the tokamak would then be carried out for just over two years before the machine reaches full plasma current operation in 2036. The reactor would then shut down for further assembly to prepare for D-T operation, which is now expected to begin in 2039. ITER fusion-reactor schedule slips by five years
Speaking today at a press conference, Barabaschi notes that the delay will cost an extra €5bn. “We are still addressing the issue of cost with the ITER council,” adds Barabaschi, who did not want to be drawn on how much ITER will now cost overall due to the “complexity” of the way it is funded via “in-kind” contributions.
Sibylle Günter, scientific director of the Max Planck Institute for Plasma Physics in Garching, Germany, says that depite the news being of “no cause for celebration”, ITER is still relevant and necessary. “We are not aware of any project that will analyse the challenges as comprehensively as ITER in the foreseeable future,” she adds. “ITER has also already achieved ground-breaking engineering work up to this point, which will be important for all the fusion projects now underway and those still to come.”
In the meantime, some changes have been to ITER’s design. The material used for the “first wall” that directly faces the plasma will change from beryllium to tungsten. Barabaschi points out that tungsten is more relevant for a potential fusion demonstration plant, known as DEMO.
Officials were also celebrating the news this week that the 19 toroidal-field coils have been completed and delivered to the ITER site. Each coil – made of niobium-tin and niobium-titanium – is 17 m tall and 9 m across, and weighs about 360 tonnes. They will generate a magnetic field of 12 T and store 41 GJ of energy.
Timeline - the way to ITER
1985 US president Ronald Reagan and Soviet Union leader Mikhail Gorbachev, at their first summit meeting in Geneva, resolve to develop fusion energy “for the benefit of all mankind”.
1987 Work on the conceptual design begins, with the EU and Japan joining the US and Russia on the project. Conceptual design completed two years later.
1992 Work on the engineering design begins with teams at San Diego, Garching and Naka. Completed in 1997.
1998 US withdraws due to €10bn price tag.
2001 Revised design completed, resulting in the cost of the project being halved to €5bn.
2003 US re-joins ITER with China and South Korea also signing up. Partners meet but fail to agree on a site leading to an 18-month stalemate.
2005 The EU and Japan agree on ITER’s home being Cadarache in southern France.
2006 India joins ITER. The ITER Organization is formally established by treaty and civil engineering begins.
2010 Detailed design finalized. Cost estimate rises to around €15bn, with building construction starting.
2011 Construction delays push back the date of first plasma from 2016 to 2019, revised to 2020 a year later.
2014 An independent report warns that the project is in “a malaise” and recommends a management overhaul. Manufactured components of the reactor begin to arrive for assembly.
2016 ITER Council agrees new “baseline” plan with first plasma set for 2025 and deuterium–tritium fuel only being used from 2035 onwards.
2020 Assembly of ITER begins while the COVID-19 pandemic hits the project’s supply chain and quality control.
2024 New “baseline” announced for start of operation in 2034.
