Inside ITER: Engineering the Future of Fusion
As the world’s largest fusion experiment overcomes design, safety, and diplomatic hurdles, its global impact may be just beginning
Deep in southern France, the ITER complex embodies humanity’s most audacious energy experiment: harnessing nuclear fusion—the reaction that powers the Sun—on Earth. But ITER is more than a research reactor; it is a global collaboration involving 35 nations, tasked with proving that fusion can deliver more energy than it consumes.
Despite its groundbreaking ambition, the project has long been targeted for its complexity, delays, and soaring cost—an estimated €22 billion ($27.9 billion).
Critics question whether such a vast public effort is still relevant in a world where fast-moving startups appear to be narrowing the gap to ignition. But at a recent panel in London, ITER’s Director of Communication, Laban Coblentz, made the case for why the project remains irreplaceable.
“It’s fair,” he acknowledged, when asked whether ITER deserves its reputation for being expensive and slow. “But that cost calculation is incomplete.”
More Than a Price Tag
Coblentz argued that the usual cost-per-kilowatt metrics miss the broader value that ITER delivers.
“One is waste disposal, which is much cheaper with fusion than fission,” he said. “But the other one is war. I’ve never seen a calculation that incorporated the cost of armed conflict over fossil fuels.”
While the project’s budget is often cited as a reason for skepticism, Coblentz offered a striking comparison: “Europe imports about the equivalent of that 22 billion euros every three weeks in petroleum costs.”
ITER, in other words, may be expensive, but it’s also proportionate to the scale of the problem it seeks to solve.
ITER is a testing ground not only for plasma physics but also for global collaboration. For over a decade, it has coordinated technical, logistical, and industrial cooperation across rival nations.
Regulatory Recalibration
One of ITER’s most significant obstacles is regulation, not plasma physics.
In particular, the French nuclear safety regulator, ASN (Autorité de sûreté nucléaire), posed unexpected complications. Formed in 2006 to oversee nuclear safety and transparency, ASN brought a framework grounded in fission-era assumptions to fusion.
“They chose to take their vast knowledge of fission and apply it to fusion,” Coblentz said. “That is a real mismatch.”
The result was oversized safety margins and excessive shielding requirements—factors that jeopardized the physical stability of the reactor structure. “We were going to have to incorporate so much radiation shielding that we ended up overpowering the base plate on which we’ve got everything.”
Rather than clash with regulators, ITER adjusted. “We stepped back and said, ‘We’re going to get to Q equals 10, but we’ll do it with low neutron fluence.’”
This approach lets ITER achieve critical scientific goals while managing regulatory demands and simplifying engineering risks.
The Q value refers to the ratio of fusion power produced in a nuclear fusion reactor to the power required to maintain the plasma in a steady state. An ideal Q-value would be greater than 25.
Building the Ecosystem
Speaking at The Economist’s “Fusion Fest” in London on April 8, Coblentz challenged the idea that agile private companies are outpacing public megaprojects like ITER.
“That is an oversight and a very understandable and common narrative,” he said. “Many journalists perpetuate it, and I think it’s naive.”
Instead, he argued that ITER has laid the industrial and scientific foundation for the entire fusion ecosystem. “We’ve created this supply chain,” he said.
A corridor in ITER’s facility features 250 plaques, each representing a company that helped develop its parts and systems. Among them are Siemens, General Atomics, Hyundai, Mitsubishi, and dozens more, many of whom took on demanding technical challenges without immediate profit.
“Whoever gets there first, that’s your Model T Ford,” said Coblentz. “ITER will help you get to a Ferrari.”
To widen its impact, ITER is now sharing its accumulated expertise. It plans to publish a 1,000-page design handbook, with the first 500 pages publicly available by year’s end. Meanwhile, hundreds of internal technical documents are being reviewed for release to qualified institutions and startups.
“Commonwealth Fusion Systems and University of Wisconsin–Madison are already asking, ‘Can we get these?’” Coblentz said.
Toward a Global Fusion Framework
Coblentz also spotlighted opportunities for countries with strong manufacturing but weak startup ecosystems, like India.
After visiting companies such as Tata and Larsen & Toubro, ITER’s leadership was stunned by their advanced fabrication capabilities. “I don’t know anywhere in the US or Europe that has the fabrication capabilities that I saw in India,” he said.
Yet, he noted, India has only a few early-stage private fusion firms. That mismatch presents a global opportunity: leverage world-class infrastructure where it already exists and link it with rising innovation hubs.
China, meanwhile, remains both a partner and a reference point. ITER has worked with the EAST tokamak in Hefei, using it to test materials such as tungsten, which is now integral to ITER’s first wall design. And despite geopolitical tensions, collaboration has endured.
“ITER is the one project, other than the International Space Station, that is exempt from European sanctions, even through the Ukraine conflict,” Coblentz said.
He also urged the international community not to dismiss China's methods, despite concerns over intellectual property.
“If China has this reputation for stealing IP, don’t just bash them. Emulate them. Learn from what they’re doing,” he said. “Fusion will need to replicate some of those things intelligently if we want this to be the generational change for our kids that we hope it will be.”
As ITER looks toward its next phase—first plasma, now expected in the early 2030s—it’s becoming less a monument to theoretical science and more a strategic hub for applied knowledge, international alignment, and technical readiness.
“We’ve turned a big corner,” Coblentz said. “We’re finally getting to the point where we’ll have efficient processes in place to do that.”
Fusion’s future may still rest on a combination of public and private breakthroughs—but wherever it starts, ITER will remain the place where it all connects.