Probe Positioning System for Heat Exchanger Inspection

Abstract

In 2002, Hydro-Québec's Gentilly-2 (G2) Nuclear Power Plant commissioned the Hydro-Québec Research Institute to integrate its SCOMPI technology into their Eddy Current heat exchanger inspection setup. The purpose of this project was to develop an automated, fast, precise, and reliable positioning device, which would be adaptable to several heat exchangers, including steam generators. Hydro-Québec's SCOMPI robot is a portable, six axes robot, developed in 1992 for the repair and maintenance of turbine runners. Given the name “REC System”, the integrated SCOMPI robot was first used during the 2003 moderator and shut-down cooler heat exchanger inspections. In 2005, the REC System replaced its SCOMPI technology with that of the newer Mini-SCOMPI, and was afterwards used to inspect two G2 steam generators. The Mini-SCOMPI is a smaller version of the SCOMPI which allows one-man, quick and easy installation. Both the 2003 and the 2005 campaigns were successful, with the REC system integration proving to be nearly transparent to the inspection process. No failure or time losses occurred during these inspections and all of the heat exchangers' tubes were accessible. In addition, probe positioning was very efficient thanks to the Mini-SCOMPI and the vision system. In 2005, half of the tubes belonging to Steam Generators 1 and 2 were inspected from the inlet side. In the future, all heat exchanger inspections with the REC System will be performed using the Mini-SCOMPI. The 5th CNS International Steam Generator Conference provides us with an excellent forum for presenting the successful integration of a new technology into an existing system for the inspection of various types of heat exchangers.