Design & development of robotic system for SS 316L pipe cutting & welding within EC launcher system in DEMO nuclear fusion power plant

Abstract

This bachelor’s thesis investigates the design and development of a robotic system for remote pipe cutting, welding and handling within the pipe forest of the EC launcher system in the DEMO nuclear fusion power plant. The work was motivated by the required development of remote systems to handle maintenance tasks within the constrained, high radiation DEMO environment. 22 SS 316L pipes must be cut, and later rejoined, to allow for the removal of components in the EC launcher system. The thesis uses a literature-based concept design approach in which the workspace and environmental constraints were identified in order to form task requirements, after which robotic systems, actuation methods and modes of control were analysed to determine which system could perform the given task.

The literature review found that a dual-arm water-hydraulic assisted-teleoperation manipulator consisting of rotary vane actuators and prismatic joints was the most suitable robotic system to perform the task. A proposed conceptual CAD model was then developed using design inspiration from existing literature and adapted by the addition of hydraulic motors and additional degrees of freedom to better suit the system requirements determined by the constraints presented.

The payload of a single arm was found to be 129.75kg by carrying out a worst-case posture payload analysis. The conclusion of the study is that while the proposed design appears to be a feasible concept, further work is required on material selection, sensing and control system design, tooling integration and verifying remote operation capability in high radiation environments.