Innovative ultrasonic imaging reactor vessel examination technology for Section XI, Appendix VIII

This paper discusses the advantages of advanced ultrasonic imaging technology to assure the accuracy and high confidence levels required to satisfactorily complete a difficult performance demonstration program. Technical problems relative to application of ultrasonics through weld deposited stainless steel cladding are discussed as well as the empirically developed solutions to these problems. Other areas covered in the paper deal with advanced calibration techniques which depart significantly from classical amplitude-based calibration, and non amplitude-dependent detection and sizing techniques which assure reliable detection and characterization of flaws. In order to take maximum advantage of the latitude allowed by appendix VIII, new techniques that saved time and improved results were developed and empirically proven and demonstrated. The program included development of innovative new search unit designs which significantly enhanced flaw detectability and sizing. (author)