Underwater wall climbing robot for nuclear pressure vessel inspection

The paper describes the development of an underwater teleoperated wall climbing robot that can carry another pipe crawler robot to nozzle openings inside a nuclear pressure vessel CPV). The wall climbing robot is positioned over each nozzle in the pressure vessel via teleoperation using visual feedback. The pipe crawler robot then transfers into the nozzle where it non-destructively tests circumferential welds located at a distance of 700mm from the inside walls of a pressure vessel. The results of trials with the robot in water tanks and a mock-up of the PV are presented. The paper describes the performance of the two underwater wall climbing robot prototypes, with emphasis on the design of a highly manoeuvrable robot and the performance of a special design of suction cups that have a low coefficient of friction and permit motion in cylindrical pressure vessels. Copyright © 2008 by World Scientific Publishing Co. Pte. Ltd