Remote inspection and welding of difficult to access reheater pipes in Advanced Gas-Cooled Reactors (AGR) 

James Fisher Nuclear was tasked with the design and development of a bespoke remote inspection and repair system to remotely; identify a leak, clean the leaking tube ends, and insert and weld a plug to isolate the tube from the steam circuit at both inlet and outlets in the UK’s AGR reactor fleet.

James Fisher Nuclear has developed a bespoke, remote inspection and repair manipulator. The deployment head is compatible with different tools to sense gas leaks, clean the leaking tube, insert and weld the plugs. The system can be lowered through a narrow penetration to the tube sheet, locked into position, and, using several actuated joints, perform all operations. 

You can read the complete paper here