THE ROLE OF VISUAL INSPECTION IN PLANNING FOR CHEMICAL AND MECHANICAL CLEANING

摘要

From the beginning, the commercial nuclear power industry has faced many difficult challenges. For the Pressurized Water Reactor (PWR) family, steam generator maintenance and repair costs are paramount. Worldwide, utilities have spent billions of dollars on steam generator inspection and repair due to tube corrosion. Several utilities have replaced steam generators. Recent history has shown that most of the corrosion and fouling takes place on the secondary side of steam generators. Visual inspection tools are now providing much of the information necessary to plan when and what methodology should be used to remove the corrosion drivers. Prior to 1989, visual inspection was mainly used to look for foreign objects or assess component damage. In 1989, a USA utility visually inspected the upper internals of their PWR steam generators. The results changed the approach to steam generator maintenance adopted by the PWR commercial nuclear industry Visual inspection is now the primary method used to plan for and assess chemical and mechanical cleaning results. Rapid advancements in visual technology and the ability to deliver it to previously inaccessible locations, is aiding industry in appraising components and determining where to take action. Inspection results help decide what cleaning technology offers the best opportunity for success.