Vistas has successfully performed numerous reactor head visual inspections for boron leakage since the spring of 2001. A specialized 6 x 4 x 1.8 inch magnetic crawler is utilized and all inspections are completed with low dosage to the crew.
The crawler incorporates a high-resolution pan and tilt camera, remote focus color camera in the front and a high resolution fixed color camera in the rear of the unit (The rear camera is necessary to ensure unimpaired exit mobility for the crawler and to support umbilical management). A VT card is used to calibrate camera resolution. The crawler also has fore and aft variable LED arrays; magnets in the chassis powerful enough for climbing vertical and overhead ferrous surfaces; and two tracks that allow excellent mobility on the reactor head between the penetrations. The system also contains a variable pressure blower for clearing loose debris. The umbilical is 100′ long. The bare head inspection requirement is also satisfied with this inspection system.
Customer procedures and quality plans are strictly followed. Original DVDs or digital tapes and final reports with detailed 360 degree photos of each CRDM are submitted to the customer prior to Vistas departing the site.