ITER vacuum vessel sector modules continue to be installed in the tokamak pit

Vacuum vessel fabrication and module build

ITER’s plasma chamber, the vacuum vessel, is the structure that houses fusion reactions and serves as a first safety containment barrier. With an interior volume of 1,400 cubic metres, the chamber will be formed from nine wedge-shaped steel sectors measuring more than 14 metres in height and weighing 440 tonnes each. When assembled, the ITER vacuum vessel is described as having an outer diameter of 19.4 metres, a height of 11.4 metres, and an approximate weight of 5,200 tonnes. After installation of in-vessel components including the blanket and the divertor, the vacuum vessel total weight is stated as 8,500 tonnes. Each sector module includes a vacuum vessel sector, two toroidal field coils, thermal shields, and auxiliary components, with lifting equipment and stabilising beams attached for the lift operation.

Core sector-module installation progress

The fabrication of the vacuum vessel sectors is shared between Europe (five sectors) and South Korea (four sectors). South Korea’s initial responsibility covered producing two vacuum vessel sectors, and an additional agreement in 2016 extended its scope to produce two more sectors originally assigned to the EU. Sector modules that make up the ITER core have been progressively installed within the tokamak pit since April 2025. The sixth tokamak sector module, #1, weighing about 1,100 tonnes, was transferred from the Assembly Hall and lowered into the pit in a coordinated lifting operation that mobilised more than 100 people, took 30 hours, and concluded on 28 July. The suspended load, including its lifting rig, is described as nearly 1,400 tonnes. The latest sector installation is said to bring two-thirds of the torus-shaped core into place. With sector module #1 now complete, it joins the five others already in the tokamak pit: #4, #5, #6, #7 and #8.

Schedule outlook for remaining modules and torus joining

ITER states that it is on track to install the final sector module in mid-2027, with teams continuing to identify opportunities for further schedule optimisation. The project says it expects a seventh sector module to be transferred before the end of the year. Once all nine sector modules are positioned in the pit, teams will proceed with the work of joining the sectors to complete the torus.

ARC signs multiyear INL framework for ARC-100 first deployment

ARC Clean Technology announced that it has entered into a Strategic Partnership Project agreement with Battelle Energy Alliance, identified as the management and operating contractor of Idaho National Laboratory. The agreement sets out a multiyear framework for collaboration between ARC and INL.

Under the framework, the parties will work on the design, demonstration, and first deployment of ARC-100, which ARC describes as a 100-MWe sodium-cooled fast reactor.

The arrangement is positioned as an early partnership model for a first-of-a-kind reactor effort, spanning multiple phases from design through demonstration and initial deployment. For supply-chain and procurement stakeholders, the announcement signals an organized interface between the reactor developer and INL’s operational leadership during the run-up to first deployment.

As the work proceeds under the Strategic Partnership Project agreement, the collaboration scope described by ARC centers on technical development and the pathway to initial deployment of the ARC-100 unit.

Site preparations begin for planned Kola NPP-2 units

Ceremony launches preparatory phase

A ceremony held on Wednesday marked the beginning of works to prepare a site for a future nuclear power plant at Kola. The event was attended by the Governor of Murmansk Andrey Chibis, the management of the Kola plant, and representatives from the general contractor, JSC Titan-2.

Officials said the activities underway do not constitute the official start of construction for a nuclear unit, which will come later. Preparatory work will include survey work, design and preparation of a construction base, and ensuring access roads and facilities for the future workforce.

Licensing and reviews precede main construction

The main construction phase is expected to begin after the design is completed, expert reviews have been completed, and the construction licence is received from Rostekhnadzor. Rosatom characterised the milestone as a major project extending beyond the current decade.

Vasily Omelchuk, Director of the Kola NPP, said the plant is building on experience from operating existing facilities, noting established processes and a high level of professionalism. He also linked personnel readiness to training and workforce transitions, saying the project will include training young specialists and transferring employees to new capacities as existing units are decommissioned.

Planned reactor configuration and workforce needs

The plan described by Rosatom is for four new units at Kola II using the VVER-S design. Rosatom describes this as a 600 MWe water-cooled reactor under development, with the first two units scheduled to be built between 2027 and 2037.

Rosatom said the VVER-S approach is intended to replace the existing four Kola units as they reach the end of their operating lives. The existing units are VVER-440 reactors: Units 1 and 2 are V-230 models, and Units 3 and 4 are of the V-213 type. The source states their capacity is 411 MWe and that they were connected to the grid between 1973 and 1984.

Chibis said the construction phase would create over 5,000 new jobs and that operation would require hundreds of highly qualified specialists. He also said commissioning Kola NPP-2 would support industrial enterprises and social infrastructure in the Murmansk Region by helping ensure uninterrupted power supply.