DEVELOPMENT OF ULTRASONIC TOMOGRAPHY TECHNIQUES FOR DIAGNOSTICS OF NUCLEAR POWER PLANT PIPING

摘要

Computerized ultrasonic tomography techniques have been elaborated for the assessment of parameters of metal condition in thick-walled NPP piping. The techniques have been implemented in a scattered-signal ultrasonic tomographic scanner. They are based on scanning the piping outer surface using a direct piezoelectric transducer, recording of back-scattered signal, tomographic reconstruction of scattering ability of metal, and assessment of metal degradation on the basis of tomographic images.