Status on Design and Construction of the ITER Buildings and Plant Systems

The Tokamak complex building construction is progressing on the ITER site. This consists of the Tokamak building hosting the machine, the Tritium building and the Diagnostic building, together with a wide range of auxiliary buildings, such as those for the heating systems, cryoplant, power supply, or the assembly of the Tokamak machine. The ITER project applies a staged approach, with the first plasma phase scheduled end of 2025, followed by the Prefusion power operation phase I and II, and finally the Tritium phase scheduled in 2035. As a consequence of the staged approach, the schedule of the building construction and plant systems installation has to be organized accordingly, and the plant configuration for each phase has to be defined. While the manufacture of the long lead items for the Tokamak machine is currently ongoing, the plant systems are completing the final design and manufacturing design, in order to start the manufacture of the components to be ready on time for the start of the installation works in the buildings. This paper gives an overview of the building overall integration and design process, and the construction status of each building. This paper further highlights the definition freeze and control of the physical and functional interfaces which are needed, in order to decouple the plant systems design and reducing the risk of possible changes propagated to the more advanced and mature interfacing systems. The newly introduced staged approach is described with the requirements on the four plasma phases.