Use of robotics for inspection and maintenance of Connecticut Yankee Series 27 Steam generators

Inspecting and maintaining nuclear steam generators (SG) provides a unique challenge to all utility, plant, and vendor personnel. The need to use robotics to remotely perform all SG primary-side inspections, maintenance, and repair including tube plugging and plug repair, in very high radiation fields and in several SG's simultaneously required careful planning and coordination to meet all schedule requirements and keep personnel radiation exposure ALARA (as low as reasonably achievable). Robotics were first used extensively at Connecticut Yankee (CY) during the 12989-1990 refueling outage for the inspection and repair of the primary side of the Westinghouse ({und W}) Series 27 SG's by B and W Nuclear Service Company, Special Products and Inspection Services Division. The workscope included a 100 percent full length eddy current inspection of all tubes in all four SG's, visual inspection of all W ribbed plugs, repair of suspect W ribbed plugs using BWNS plug-a-plug retainers and plugging of all defective tubes.