Non-destructive measurements of fuel cladding thickness

Abstract

The method of non-destructive measuring the thickness of small-diameter thin-walled pipes consists of using the reso-nant frequency of vibrations in the plane of the pipe cross-section to determine the pipe wall thickness. The relative ratio of the measured frequencies determines the thickness of the thin-walled pipe with great accuracy. For small pipe diame-ters, the method achieves the most accurate results. The accuracy of the measurement is directly dependent on the thickness of the pipe wall and for very thin walls the method achieves the highest accuracy. The invention relates to a method of non-destructively measuring the thickness of pipes that can only be accessed from the outside or just possi-bly from the inside. Particularly good results are obtained with thin-walled pipes of small diameter, such as nuclear fuel cladding or steam generator pipes. Measurement of the cladding thickness is important for downstream activities such as nuclear fuel inspections or thermomechanical calculations. The non-destructive form of measuring the thickness of thin-walled components such as fuel claddings opens the possibility of expanding activities within the inspection of en-ergy equipment to other areas of industry, testing, or structural diagnostics.