The ITER Organization has overall responsibility for the successful integration and assembly of components delivered to the ITER site by the seven ITER Members. This includes the assembly of the ITER Tokamak, with its estimated one million components, and the parallel installation and integration of plant systems such as radio frequency heating, fuel cycle, cryogenic, cooling water, vacuum, control, and high voltage electrical.
Hundreds of thousands of assembly tasks, organized into construction work packages, have been carefully planned and organized by ITER engineers and schedulers. While the ITER Organization is responsible for the surveillance of all construction activities and final compliance with requirements—including nuclear safety requirements in France—the work will be carried out by contractors selected for their industrial know-how, experience, resources, skills and proven track record.
The construction platform has been divided into three distinct assembly zones: tWorksite 1 (Tokamak Pit, Assembly Hall and Cleaning Building) focused on the assembly of the ITER Tokamak; Worksite 2, focused on the Tokamak Complex plant systems directly connected to the machine; and Worksites 3-6 for balance of plant activities (all plant and auxiliary buildings).
The organization of the ITER worksite for assembly and installation activities.
In its role as overall assembly integrator, the ITER Organization is assisted by:
A Construction Management-as-Agent (CMA), whose role is to plan, manage, and supervise the works of the assembly phase including contract preparation, daily contract management, execution supervision, and site coordination. The MOMENTUM Consortium—formed by Wood (UK), Assystem (France) and KEPCO E&C (Korea)—was selected as CMA contractor in 2016.
Assembly contractors working under contracts awarded by the ITER Organization. (Nine major assembly and installation contracts are foreseen.) Construction work packages will be released by the ITER Organization in achievable—and trackable—batches. From the construction work packages, the assembly contractors will generate the installation work packages that define the execution details of each task.
Assembly contractors working under the Domestic Agencies. In a limited number of cases—for example the welding of the cryostat sections in the Tokamak pit by Indian Domestic Agency contractors, or the installation of remote handling equipment—the procurement scope of a component or system includes on-site installation work managed by the Domestic Agencies.
During Assembly Phase I, from March 2020 to December 2024, the ITER Organization will focus on the assembly of the core machine as well as systems essential for First Plasma operation. (See "The World's Largest Puzzle," below.) This period is followed by integrated commissioning, culminating in First Plasma.
Assembly Phase II is planned from June 2026 to June 2028. During this phase, contractors introduce in-vessel components such as the ITER divertor, blanket and in-vessel coils through machine ports , in some cases using remote handling devices. Additional diagnostics and heating systems will be installed. (See the video "In-Vessel Components," below.) An operational campaign in hydrogen and helium will follow.
The shutdown planned from June 2030 to September 2031, Assembly Phase III, is dedicated to installing the heating and diagnostic neutral beam systems, bringing radiofrequency heating systems to full capacity, and installing the ITER test blanket modules. Two years of experimentation at full heating power will ensue.
Finally, the implementation of ITER's full tritium plant and hot cell facility during Assembly Phase IV (March 2034 to March 2035) opens the way for fusion power operation in June 2035.