ITER's Progress and Europe's Role in Fusion Energy

Europe stands as one of the most ambitious scientific endeavours in human history as the global energy landscape transforms towards sustainable solutions. With ITER taking shape in southern France, the continent is positioning itself as the leader in fusion energy development—a technology that promises to revolutionise how we generate clean, abundant power. As the World Nuclear Exhibition 2025 approaches, Europe's role in delivering fusion energy at a global scale becomes increasingly significant.

Located in Saint Paul-lez-Durance in southern France, ITER (which means "The Way" in Latin) represents unprecedented international collaboration in pursuit of fusion energy. In southern France, 33 nations are collaborating to build the world's largest tokamak, a magnetic fusion device that has been designed to prove the feasibility of fusion as a large-scale and carbon-free source of energy based on the same principle that powers our Sun and stars.

The scale of ITER is staggering. The world's largest tokamak—twice the size of the largest machine currently in operation, with six times the plasma chamber volume. When operational, ITER is designed to yield in its plasma a ten-fold return on power (Q=10), or 500 MW of fusion power from 50 MW of input heating power, making it the first fusion experiment in history to produce net energy gain.

Europe's commitment to ITER extends far beyond hosting the facility. As the largest contributor to the project, Europe is responsible for the largest portion of construction costs (45.6 percent). The European Union has further demonstrated its commitment through significant budgetary allocations, with €5.61 billion allocated to the project between 2021-2027.

ITER has made substantial progress since construction began in 2010. Machine assembly was launched with the central Tokamak Building handed over to the ITER Organization in March 2020 for the start of machine assembly, with the first major achievement being the installation of the 1,250-tonne cryostat base in May 2020.

However, the project has faced significant challenges that have necessitated timeline adjustments. In a major update announced in 2024, the giant fusion reactor known as ITER will not turn on until 2034, 9 years later than currently scheduled. The updated timeline shows that the start of the deuterium-tritium operation phase in 2039 represents a delay of four years from previous projections.

Despite these delays, the revised approach prioritises scientific robustness. The new baseline prioritises a robust start to scientific exploitation with a more complete machine than initially planned, with a divertor, blanket shield blocks and other key components and systems in place.

Europe's ambitions extend well beyond ITER itself. Recent strategic documents highlight the continent's comprehensive approach to fusion energy development. Mario Draghi's report (2024) on the future of European competitiveness calls for an EU strategy on fusion and the creation of a public-private partnership to promote its quick commercialisation.

The European Commission recognises the need for a stable and predictable fusion ecosystem for industrial innovation, leveraging the ITER project, while ensuring a clear technology development roadmap. This strategic approach positions Europe to capitalise on the knowledge and experience gained from ITER for commercial applications.

ITER's scientific objectives are precisely defined to bridge the gap between experimental fusion research and commercial power generation. The facility is designed to achieve several crucial milestones:

Burning Plasma Demonstration: The primary objective of ITER is the investigation and demonstration of burning plasmas—plasmas in which the energy of the helium nuclei produced by the fusion reactions is enough to maintain the temperature of the plasma.

Technology Integration: ITER will also test the availability and integration of technologies essential for a fusion reactor (such as superconducting magnets, remote maintenance, and systems to exhaust power from the plasma).

Tritium Breeding: ITER will provide a unique opportunity to test mockup in-vessel tritium breeding blankets in a real fusion environment, addressing one of the key challenges for future commercial fusion power plants.

The path from ITER to commercial fusion power is becoming increasingly clear. ITER will bridge the gap between today's smaller-scale experimental fusion devices and the demonstration fusion power plants of the future. The project's mission extends beyond scientific demonstration to practical preparation for commercial applications.

Fusion for Energy, the European Union's organisation responsible for Europe's contribution to ITER, emphasises that the mission is to make fusion energy a reality through involvement in ITER, with this knowledge being used towards the development of commercial fusion power plants.

The growing momentum in the fusion sector is evident from recent developments. With recent technological breakthroughs and increased private investments, the fusion industry is gaining momentum, suggesting that the transition from ITER's experimental success to commercial deployment may occur more rapidly than previously anticipated.

Europe's leadership in fusion energy comes at a time of increasing global competition. While ITER represents international collaboration, individual nations are developing their own fusion strategies. The United States has launched its own comprehensive approach, with the Department of Energy aiming to realise a commercially relevant, private sector-led fusion pilot plant in the 2030s.

This competitive landscape makes Europe's early leadership through ITER even more strategically significant. The knowledge, experience, and industrial capabilities developed through ITER provide Europe with substantial advantages in the race to commercialise fusion energy.

Beyond ITER, Europe is building a comprehensive fusion energy ecosystem. Recent analyses suggest that now is the time for Europe to show vision to harness the full potential of this "disruptive technology". This ecosystem includes not only the experimental facilities but also the industrial supply chains, research institutions, and regulatory frameworks necessary for commercial deployment.

The European approach recognises that fusion power plants will offer steady and reliable energy, providing "baseload" electricity, addressing one of the key challenges in renewable energy deployment—the need for consistent, weather-independent power generation.

As the nuclear industry prepares to gather at the World Nuclear Exhibition 2025 at Parc des Expositions – Hall 6, Villepinte, from 4-6 November, fusion energy will undoubtedly feature prominently in discussions about delivering fusion energy at a global scale. The event provides an ideal platform for showcasing Europe's leadership in fusion technology and discussing the pathways from experimental success to commercial deployment.

The timing is particularly relevant, as ITER moves through its assembly phase towards its Start of Research Operation planned for 2034. The nuclear industry gathering will offer opportunities to discuss the integration of fusion technology with existing nuclear infrastructure and the role of fusion energy in the broader clean energy transition.