Study and design of locking system for fusion reactor lower port closure plate

Abstract

The goal of the DEMO fusion reactor is to rapidly and reliably generate electricity using remote maintenance tools while following the safety requirements set for the operators, the reactor and the environment. To fulfil this goal, the containment barriers inside of the reactor, specifically the port closure plates, need to be secure and need to work efficiently together with remote maintenance tools. The existing locking system for the lower port closure plate is insufficient, and a new mechanism is needed. It was found that the locking mechanisms that are used in bank vault doors and in ship’s bulkhead doors are both designs that fit the port closure plate requirements. Both locking systems were successfully 3D modelled, and rendered studies of their movements were created. Lastly, prototypes of the models, which displayed the locking and unlocking movement of the models, were 3D printed. The two locking designs were scored and compared using an evaluation matrix to analyse various aspects of the systems. It was concluded that the design based on a heavy bank vault door locking system was the most suitable for the reactor application out of the two designs. The design securely locks the port closure plate, creating a reliable containment barrier in the reactor’s lower port. The design was created to be rapidly operated by remote maintenance tools, which is a requirement set for the port closure plate. The final design fits the safety-oriented engineering and technological constraints outlined for the DEMO fusion reactor. Overall, the design is promising and could be utilized in the reactor lower port closure plate after additional testing, modifying and refining. Additionally, the design can be improved and adjusted to be of use in the upper and equatorial port closure plates, as well as other reactor applications.