Non-Destructive Evaluation Methods for Nuclear In-Process Weld Inspection

The manufacture of heavy vessels within the nuclear industry from ferritic and austenitic steels is dependent on successfully welding seams, joints and circumferences to high levels of quality. In order to minimise the need for rework of the welded seams and joints costly, time-consuming, and potentially hazardous mid- and post-manufacture radiography is used for Non-Destructive Testing and Evaluation (NDT/E). This report evaluates the current ‘state-of-the-art’ for in-process NDT/E of heavy vessel welding in the nuclear industry and considers alternative NDT/E techniques and approaches which can address the issues of traditional mid- and post-manufacture testing. Chapter 2 considers welding processes in the nuclear industry by evaluating a variety of welding techniques commonly used in the nuclear industry, alongside the different welding joint and configurations, before moving on to discussing defects that typically occur during welding. The chapter concludes with a summary of weld inspection options during the welding process. Chapter 3 details a review of the current literature for4 NDT/E categories: Ultrasonic, Electromagnetic, Acoustic Emission, and Optical. Where appropriate, within these categories different NDT/E methods have been researched and evaluated. Each NDT/E method was assessed against a range of criteria, to determine the suitability of a given NDT/E method for in-process weld inspection and monitoring.