Fiber-optic instruments help keep nuclear plant humming
Technicians at the Point Beach Nuclear Plant of Wisconsin Electric Power Co. are using an Olympus Videoimagescope in the radiologically controlled area, as well as the clean side of the plant. Whether it`s looking inside feedwater heat exchangers, pipes on the clean side, spent-fuel storage casks or sump valves in containment, the technicians are able to determine that everything is clean and operating efficiently. When working in radioactive areas, equipment is protected from contamination by plastic coverings, which are later disposed of according to accepted procedures. The Olympus Videoimagescope contains a long fiber-optic probe (usually 25 to 75 ft long) that transmits powerful light from an external source and out through the tip to illuminate the area being studied. A CCD “chip” camera at the tip transmits the full-color image to the electronic processing unit for projection on the video monitor. Here it can be viewed by several people at once and stored on disks or videotape for further study and image analysis.
A typical nuclear application for the Videoimagescope is to examine the sump valves below the floor inside the containment vessel, ensuring there is no debris at the bottom of the hydraulic lift. Another challenging job is inspection of the dry, fuel-storage containers used to store spent-fuel rods and to ensure there is no debris inside. On the plant`s clean side, technicians have used the Videoimagescope to examine the feedwater heat exchangers and look for any erosion, debris or signs of leaks. Michaelson and his colleagues stress the importance of cleanliness. Every time they open a pipe or equipment connection, they probe to ensure there are no foreign materials, shavings of metal, or dirt or debris.