Europe completes the final ITER Vacuum Vessel sector

Europe has achieved a massive industrial feat in its contribution to ITER. The fifth and last European Vacuum Vessel sector exited the factory this week to join the world’s largest fusion reactor, under assembly in France. Fusion for Energy (F4E) and the AMW consortium, formed by Ansaldo Nucleare, Westinghouse, and Walter Tosto, worked together to manufacture this component on time. Its delivery will mark the completion of a 15-year project that involved a supply chain of 15 European companies.

The Vacuum Vessel forms the stainless-steel heart of the ITER device. Inside it, a plasma will be heated up to 150 million °C so hydrogen atoms can fuse together, releasing huge amounts of energy. The vessel, shaped like a doughnut and hermetically sealed, is designed to keep impurities out and safely contain the extreme environment within. It is made up of nine D-shaped sectors, five made in Europe and four in Korea. Once joined, the chamber will measure 19.4 meters across and weigh 5,200 tonnes.

The sectors’ size, combined with stringent geometry and safety requirements, set an unprecedented benchmark for manufacturers. But Europe’s industry rose to the challenge. F4E and its partners mobilised a skilled workforce: at least 150 professionals, from engineers to welders or quality officers, across various workshops. F4E also collaborated with ITER Korea, sharing best practices.

The process involves thousands of tasks, performed with great precision. The raw steel forgings are cut, machined and joined into four segments, which are then assembled into the final sector. In total, one sector counts over 150 km of welding beads, rigorously inspected to ensure a seamless fit.

Sector 2 came together at the Westinghouse Electric Italy workshop in Monfalcone. With four sectors under their belt, the consortium’s teams had learned to master complex assembly and machining processes. But this time they had to do it faster. With only months to go, the delivery date was brought forward due to the quick progress in ITER’s on-site assembly.

The project did not crack under pressure. “It was a last uphill stretch, but we managed to keep the momentum across suppliers and complete this sector faster compared to others” said F4E Programme Manager, Boris Bellesia. He puts it down to two words: resilience and teamwork. “Our teams and partners stayed committed and always acted in the interest of the project, beyond a customer-supplier dynamic,” he added.

“We are extremely proud of this achievement. The project presented exceptional technological and managerial challenges, but by coordinating across multiple facilities, we completed the EU sectors in line with the new ITER baseline. It’s a remarkable result, achieved thanks to years of hard work by all our colleagues and close collaboration with F4E,” stated AMW Project Director, Luca Ascione.

“The completion of Europe’s final sector marks the end of a journey, which started two years ago when F4E delivered its first Vacuum Vessel sector to ITER. This success belongs to our staff, and industrial partners, who have shown exceptional commitment and professionalism. We finished the work in time by working as one team with our suppliers and ITER Organization. In addition, we made good use of knowledge acquired from the previous sectors and lessons learnt from ITER Korea. This demonstrates that Europe has a supply chain that is robust, effective and can manufacture the components of future fusion devices,” says F4E Director, Marc Lachaise.