Commercially available UT and Eddy current data acquisition systems were used. Customised UT transducers and ECT probes were manufactured to account for the coarse grain structure typical of the statically cast stainless steel pump casing. Dedicated scanning plates and electrical cabling were designed to interface the various probes and the data acquisition system to the inspection robot.

NDT procedure qualification (open trials) and NDT personnel qualification (blind trials) were performed to comply with the requirements of the Swedish nuclear authority. Relevant examples from the open trials shall be presented to illustrate the excellent examination capability of the method.

The first inservice inspection according to the fully qualified new concept was performed in the Ringhals 4 unit, in September 1997 : the scheduled 7-day period for the intervention was respected. For the second inservice inspection, performed in May 1998 in the Ringhals 2 unit, the examinations were completed in less than 5 days. In both cases, the detailed interpretation of all NDT examination data was finalised and reported less than 48 hours after completion of the last scanning sequence.