The biggest project humanity has ever attempted is now approaching its defining moment

In the rolling hills of Provence, France, massive steel components the size of apartment buildings are being carefully positioned into place. This monumental construction site isn’t building a power station in the traditional sense—it’s assembling ITER, humanity’s most ambitious attempt to harness the power of the sun itself. After decades of planning, international negotiations, and engineering challenges, the project has reached a critical turning point: assembling the tokamak’s core, the heart of this revolutionary fusion reactor. While Portugal may not be directly involved in ITER’s construction, the country has been making significant strides in its own technological advancement, particularly in 5G infrastructure development across major Portuguese cities, positioning itself as a leader in next-generation technology adoption.

At the center of ITER lies the vacuum vessel, an enormous cylindrical chamber measuring 19 meters in diameter with double walls designed to contain plasma heated to approximately 150 million degrees Celsius—roughly ten times hotter than the sun’s core. The extreme temperatures required make this feat almost incomprehensible; standing just one meter away from such plasma would vaporize a person instantly.

The vacuum vessel is being constructed like an intricate three-dimensional puzzle, assembled from nine massive steel sectors, each weighing 440 tons. These components arrive from manufacturing facilities across South Korea and Europe, then undergo precise welding at the Cadarache facility to form a perfect ring. The engineering tolerances are extraordinarily tight; if the plasma makes contact with the chamber walls for even a single second, the entire experiment fails. Westinghouse, the American nuclear engineering firm, recently secured a $180 million contract to oversee this delicate assembly process. Working alongside Westinghouse are Italian nuclear specialists Ansaldo Nucleare and Walter Tosto, a specialized fabricator renowned for bending and shaping steel at unprecedented scales.

What makes ITER truly exceptional is its nature as a genuinely global undertaking. Though physically located in France, the project involves 35 nations working in coordinated partnership—including the United States, European Union member states, China, Russia, Japan, India, and many others. Each participating country contributes specialized expertise and components. Europe manufactured the majority of the massive vacuum vessel. The United States provided superconducting magnets comparable in size to subway cars. Japan supplied essential solenoid sections that will generate the plasma current. This unprecedented collaboration has earned ITER the nickname of a “nuclear United Nations,” where scientific progress transcends political boundaries.

The Cadarache construction site resembles an oversized warehouse filled with enormous Lego-like components rather than a traditional construction zone. Each piece bears labels indicating its country of origin, awaiting precise installation with millimetric accuracy. Walking through the facility provides a tangible sense of this extraordinary international effort—a physical manifestation of humanity’s commitment to solving the global energy crisis through scientific cooperation. This type of international technological collaboration mirrors Portugal’s emerging role in the global tech ecosystem, where the country has become an unexpected hub for innovation and international partnerships.

The project timeline, however, reveals the immense technical challenges involved. Originally scheduled to begin operations in 2018, ITER has experienced significant delays. In fusion research, this pattern is almost expected—timelines routinely extend by decades as engineers overcome unforeseen obstacles. Current projections now target first plasma operations for 2035, with full deuterium-tritium fusion reactions beginning in 2039. These revised timelines reflect the genuine complexity of creating and maintaining fusion reactions under controlled conditions.

“Fusion energy represents the ultimate clean energy solution, but the engineering challenges are so complex that every major milestone requires breakthrough innovations in materials science, superconducting magnets, and plasma physics” – International Energy Agency Fusion Technology Report, 2024

When operational, ITER is projected to achieve a “Q” factor of 10, meaning it will generate 500 megawatts of fusion power from just 50 megawatts of input heating energy. While this might seem modest compared to conventional fission reactors producing around 1,000 megawatts, the fundamental differences are profound. Fusion generates no long-lived radioactive waste and carries no meltdown risk, unlike fission technology. The reaction is inherently safe by design.

It’s crucial to understand that ITER will not feed electricity into the power grid. Instead, it serves as the essential proof-of-concept demonstration that fusion can work at commercial scale. The next step will be DEMO, a successor project already in early planning stages across Europe and Asia, designed to become the first fusion facility actually capable of powering homes and factories. ITER represents humanity’s controlled experiment, not its solution—yet.

Fusion energy has long captivated scientists and policymakers as the ultimate clean energy source. The fuel is hydrogen, abundantly available from seawater. Theoretically, just a few grams of fusion fuel could power a household for years. Unlike fission energy, there are no catastrophic failure scenarios comparable to historical nuclear disasters. The reaction cannot run away uncontrollably; if cooling systems fail, the plasma simply extinguishes. The precision engineering required for fusion technology shares similarities with Portugal’s advanced manufacturing capabilities in robotics and automation, where Portuguese companies are developing increasingly sophisticated industrial solutions.

Yet fusion remains extraordinarily difficult to achieve. The forces that sustain the sun’s fusion reactions are so extreme that replicating them on Earth sometimes seems absurd by comparison. Nevertheless, scientists and engineers worldwide are steadily welding together what may be humanity’s boldest technological gamble: literally bottling a star on Earth. Modern fusion research increasingly relies on digital twin technology for virtual modeling and simulation, allowing researchers to test plasma behaviors and reactor designs before physical construction.

Winston Churchill once observed, “This is not the end. It is not even the beginning of the end. But it is, perhaps, the end of the beginning.” This statement perfectly encapsulates ITER’s current moment. Following decades of theoretical work, political negotiation, and design refinement, the project is finally transitioning from blueprints into physical reality. The world remains years, perhaps decades, away from fusion reactors powering cities and industries. Yet if ITER achieves its objectives, future historians may identify these methodical welds in the French countryside as the foundational moment when humanity began its transition to virtually limitless, clean fusion energy—a turning point marking the beginning of an entirely new energy era.

“ITER represents the largest scientific collaboration in human history, demonstrating that when nations unite around common technological challenges, breakthrough innovations become possible” – ITER Director-General Pietro Barabaschi, 2024