Study on the endoscopic inspection of ITER thermal shield cooling pipes

A novel endoscope is developed for the inspection of long and complex-shaped cooling pipe of ITER Thermal Shield (TS). The mechanical design of the endoscope is improved for its easier insertion into long pipe routing. Main break-through is to reduce the cable friction against metal pipe surface as well as to maintain the elastic rigidity of the cable for the insertion. Spacers are attached on both the camera head and the cable to reduce the friction. Plate spring tube is used to protect signal wire and to maintain elastic rigidity of the cable. The conceived endoscope was tested to the pipe routing mock-up, which is similar to the longest and most complex TS pipe routing. Special device is also presented for making the endoscope insertion be easier. The insertion test result is compared with that of a conventional endoscope. Several endoscopic images are also discussed for typical pipe samples and for the curved region of pipe routing.