A Camera-based Tool Pose Measurement Method for Automatic Tool Insertion for Emergent Operation of Fuelling Machine

Refuelling operations are carried out on power with the aid of two fuelling machines in pressured heavy water reactor (PHWR) system. Two fuelling machines clamp on the two end-fitting on each side of fuel channel and new fuel bundles are pushed from the upstream fuelling machine and spent fuel bundles are taken out into the downstream fuelling machine. The ram assembly of the fuelling machine pushes fuel bundles and operates the shield and closure plugs in each fuel channel, the snout plug in the fuelling machine snout, and the guide sleeve tool. In spite of periodic maintenance, there are some possibilities for the hydraulic drives of the ram to malfunction during their operation and the manual drive handles are provided to fix such problems. But in some cases the plant should be shutdown to be fixed because high dose rate inhibits the access of human workers. To mitigate such an event, KAERI developed a remotely-operated robotic system. The robotic system operates the manual drive handles for B ram and Latch ram to release the fuelling machine from the fuel channel. On-site experiments were performed successfully by KAERI and KHNP at Wolsong nuclear power plant as shown in Fig. 1 during overhaul in 2007