Construction of World’s Largest Fusion Reactor begins

Engineers started construction at ITER, world’s largest nuclear fusion project in southern France, with operations planned to begin in late 2025.

“Enabling the exclusive use of clean energy will be a miracle for our planet.”

Anyone driving to ITER can take full measure of the enormity of the project a few kilometers before reaching the destination.



Massive and complex first-of-a-kind components have been arriving at the ITER construction site in recent months from all over the world. The Tokamak Building and Assembly Hall are united. The cryostat base is installed. The cryostat lower cylinder and poloidal field coils #5 and #6 are on hand. The requisite assembly tools are largely in place.

This week, the first sector of the ITER vacuum vessel will arrive in France from Korea. Together with two toroidal field coils and sections of the silver-coated protective thermal shield, all components needed to create the first Tokamak sub-assembly will now physically be in France. Machine assembly can begin.



Teams at Fusion for Energy completed a critical milestone in late March when they successfully transferred the vast assembly theatre to the ITER Organization, while many industrial and corporate activities in France and other countries had come to a near standstill.

Laurent Schmieder, Program Manager for Buildings, Infrastructure and Power Supplies at Fusion for Energy, said:

“It has been quite a challenge. Everything was going according to plan despite the fact that we had bad weather last year. A few weeks before the March deadline, the COVID-19 episode fell upon us! Whereas 2,500 people usually work on site — including project management, contractors and consulting engineers — this number dropped to a few dozen for the first few weeks, then a few hundred. Today the number of workers on site is rising again gradually.”

Construction of World’s Largest Fusion Reactor begins

source ITER