Radiographic system for evaluation of steam-generator support-plate integrity. Final report

Radiographic techniques and equipment have been developed to identify significant damage in the support plate ligaments between tube holes and flow holes. The radiographic technique utilizes a dual source, with the source positioned equidistant above and below the plate inside a tube to provide a distribution of penetrating radiation to produce a relatively uniform density radiograph of the ligaments. Surrounding the source tube, as many as six film cassettes mounted on carriers are placed at the appropriate elevation within adjacent steam generator tubes and exposed simultaneously. The sources and multiple cassette carriers are manipulated by independent systems which utilize eddy current methods to properly locate these components with respect to the support plates. This radiographic system has been demonstrated in a realistic full-scale mock-up