DEMO vacuum vessel port closure plate sealing and fixation activities

DEMO should be as close as possible to a future fusion power plant, produce electricity and have a high level of availability. In the current Concept Design phase, the design is to be further elaborated and industry is to be increasingly involved as a partner in the development. An essential component will be the vacuum vessel (VV), which has to fulfil many tasks.

It serves as a first confinement barrier and houses in-vessel components (IVCs) that are necessary for operation. The VV has numerous openings - the ports. These are closed during DEMO operation by so-called port closure plates (PCPs). All handling of the PCPs and IVCs, as well as inspection throughout the operational phase, must be done through remote maintenance tools and without the presence of personnel.

Within the framework of qualified partners from industry the fastening and sealing of the PCPs is studied. Many requirements are associated with the technical implementation. As the development of DEMO is still in an early phase, the present goal is not yet the development to a high degree of maturity.

Instead the review of established industrial solutions regarding their suitability to DEMO as well as the identification of adapted solutions with more attractive features for the DEMO application are aimed for. In this paper, the background as well as the status of this task is explained.