Assembly and Remote Handling of ITER Plasma Facing Components

The assembly and remote maintenance of the plasma-facing components of ITER presents major challenges for the construction, operation and maintenance of ITER. The main plasma-facing components, the divertor and the blankets, are large components, with exceptionally demanding alignment requirements, and require complex support systems to sustain loads under normal and off-normal operational conditions. The plasma-facing components are designed to be maintained using special remote handling (RH) tools. These tools and the associated RH systems and processes are currently undergoing detailed design and certain key processes have been subject to extensive R&D / prototyping activities. In addition, a specific set of in-vessel mechanical handling tools are also under design for the installation of other large in-vessel components such as the ELM and VS coils and diagnostic looms. The main tools are an In-Vessel Tower Crane (IVTC) which includes a personnel platform, an in-vessel floor system to allow safe personnel-access at 4 levels throughout the vacuum vessel, and a Through Port Transfer System (TPTS) to transfer components into the vacuum vessel via the equatorial ports. A Trial, Test and Training Facility (TTTF) to validate the tools and the assembly processes is also included. These tools have been designed to be compatible with the blanket remote maintenance tools, so that the first installation of the blanket can be performed with either system, or with a combination of both as appropriate to minimize risk, optimize durations or to validate the operation of the RH systems. The first assembly of the divertor will be performed using the RH system designed for the maintenance of the system, with welding and testing activities carried out hands-on. Several thousand customized supports and connections will ensure the precise alignment of the plasma-facing components and help facilitate future remote maintenance. This will require an in-vessel datum system, state-of-the-art metrology and machining. The overall assembly process, requirements for the design of the tools, the in-vessel working environment and regime, including expectations for working in a beryllium-controlled environment during the installation of the blanket's beryllium first wall (FW) panels will be presented. Trials to date to validate the assembly and maintenance processes will also be explained. ITER is a Nuclear Facility INB-174.