French developments in the ultrasonic examination of pressure vessels

Experience gained in the ultrasonic examination of the reactor vessels of French PWRs is outlined. The development work initiated concerns: - the improvement of the knowledge of methods used; - the beginning of automation in fabrication control; - the continuation of the technical implementation of the signal and image processing. At the fabrication stage, work was carried out to demonstrate the total adequacy of those examinations required by the RCCM code. In addition, Framatome is developing the automation of ultrasonic inspection in shop. Inservice inspection of the vessel is carried out with 'MIS' inspection equipment. Data analysis is improved by special software allowing the performance of different types of UT indications to be presented. Diffraction echoes from focused probes are used to size underclad defects on reactor nozzles. (author)