The final vacuum vessel sector manufactured in South Korea for the International Thermonuclear Experimental Reactor (ITER) has arrived at the construction site in Cadarache, France. This delivery completes the Korean contribution to the nine-sector vessel, a key milestone for the assembly of the world's largest tokamak. The component, designated Sector #1, joins Sector #6, which was also fabricated in Korea and delivered in August 2023. The arrival marks the culmination of a multi-year manufacturing effort by Hyundai Heavy Industries, which was responsible for producing four of the nine sectors, along with several key port structures. The successful delivery keeps the complex assembly sequence of the main reactor vessel on its critical path. Source: ITER

Each vacuum vessel sector is a significant engineering feat, weighing approximately 400 tonnes and standing 12 metres high. The D-shaped, double-walled structure is fabricated from 60-millimetre-thick stainless steel plates. Its primary function is to contain the superheated plasma, acting as the first confinement barrier and a high-quality vacuum chamber. The space between the inner and outer walls will be filled with water for cooling and to provide neutron shielding. The nine sectors, once welded together, will form a torus with a total plasma volume of 840 cubic metres. The precision required for manufacturing and alignment is exceptionally high, as the final assembled vessel must withstand extreme temperatures, pressures, and neutron bombardment. Source: ITER

Each vacuum vessel sector is a significant engineering feat, weighing approximately 400 tonnes and standing 12 metres high.

The fabrication of the ITER vacuum vessel is a global collaboration, with the nine sectors and 54 ports being manufactured by consortia in Europe and South Korea. The European domestic agency, Fusion for Energy, is responsible for five sectors, which are being produced by the Italian consortium AMW (Ansaldo Nucleare, Mangiarotti, Walter Tosto). South Korea, through its domestic agency KFE (Korea Institute of Fusion Energy), contracted Hyundai Heavy Industries for the remaining four sectors. This international in-kind contribution model is central to the ITER project's structure, distributing the manufacturing burden and technical expertise among its member nations. The successful completion of Korea's manufacturing scope demonstrates the viability of this complex global supply chain for fusion energy components. Source: ITER

With all nine sectors now on-site at Cadarache, the focus shifts entirely to the assembly phase within the Tokamak Pit. The sectors are joined using a process of advanced robotic welding, a procedure that must be performed with extreme precision to ensure the vacuum integrity and structural stability of the final vessel. The first sector was positioned in the assembly tool in 2022. The subsequent integration of thermal shields, toroidal field coils, and poloidal field coils around the completed vacuum vessel will form the core of the fusion machine. The completion of the vacuum vessel is a prerequisite for achieving First Plasma, the initial operational milestone for the entire ITER program. Source: ITER