Optical scanner for steam generator tube inspection. Final report. [PWR]

The objective of this program is to develop and evaluate a prototype solid-state scanner for use as a non-destructive inspection device for the interior surface of steam generator tubes. Imaging of the tube was accomplished using a Reticon RO-64 self-scanning photodiode array in a scanner head with integral optics and light source. A unique data processing scheme was utilized to present the raw video in a manner which facilitates defect detection and quantification. Following development of the prototype scanner system, defects (holes, pits, cracks) and dents were simulated in tubes at Science Applications, Inc. (SAI) in order th characterize scanner performance. Results indicated that defects with a width/diameter of 0.20mm (.008 in.) and dents with a radial depth of 0.10mm (.004 in.) can be detected. In addition it was found that signal amplitudes of the defects scanned correlated well with defect size, and thus, defect width and dent depth can be measured.