ITER moves vacuum vessel sector #9 into pre-assembly tooling

ITER has moved vacuum vessel sector #9 into the Cleaning Facility and Assembly Hall, turning a completed prep job into the next concrete step in the tokamak’s build order. The sector arrived on March 6 and spent the intervening months in a building near the Tokamak Complex while crews welded and installed bosses, studs, clips, sensors and cables on both its inner and outer walls. That work is now finished, and the sector is ready to take its place in the tooling that will shape it into a full vacuum vessel module.

The pace is what stands out. ITER said the preparation took just over three months, which it described as record time for a sector with a dense sensor configuration and twice as much work activity as some earlier sectors. In a project where millimeters matter and every cable route or sensor mount has to survive the full machine build, that kind of throughput is more than a shop-floor milestone. It shows the assembly line is getting faster at handling the most intricate parts of the machine.

The move also opened a vacancy in the tokamak pit after sector module #4 was transferred there on May 26-27. As of May 27, five of the nine vacuum vessel sector modules were already in place, and a sixth is expected in the pit this summer. That sequencing matters because each sector does not just arrive and sit. It has to be positioned, checked and integrated in a carefully managed chain that keeps the pit, the Assembly Hall and the Cleaning Facility all working in lockstep.

ITER’s Assembly Hall is built for that choreography. Connected directly to the Tokamak Building, it uses two 750-tonne cranes and the Sector Sub-Assembly tool to suspend sectors while toroidal field coils and thermal shielding are installed. ITER says the broader tooling system includes 128 custom-designed tools, assembly tolerances of just 2 to 3 mm and about 1.5 million labour hours over four years. Sector #9 now enters that exact process, where precision handling becomes the bridge between fabrication and final installation.

The vacuum vessel itself adds another layer of pressure. ITER says it contains 9,000 in-wall shielding blocks, with two-thirds installed during fabrication and the remainder delivered for assembly. That is why the quick turnaround on sector #9 matters: it is not just a tidy logistics win, but part of the work that protects magnets, supports shielding and gets each sector ready for the plasma chamber it will eventually help enclose. After the three-month preparation sprint, the next lift has to land cleanly, because the whole cadence of ITER assembly depends on moments like this lining up one after another.