Feeder Pipe Inspection Robot Using an Inch-Worm Mechanism with Pneumatic Actuators

The outlet feeder pipe thinning in a PHWR (pressurized heavy water reactor) is caused by high pressure steam flow; inside the pipe, which is a well known degradation mechanism called FAC (flow assisted corrosion). In order to monitor the degradation, the thickness of the outlet bends closed to the exit of the pressure tube should be measured and analyzed at every official overhaul. This paper develops a mobile feeder pipe inspection robot that can minimize the irradiation dose of human workers by automating the measurement process. The robot can move by itself on the feeder pipe by using an inch worm mechanism, which is constructed by two grip per bodies that can fix the robot body on the pipe, one extendable and contractable actuator, and a rotation actuator connected the two gripper bodies to move forward and backward, and to rotate in the circumferential direction