A Size Evaluation for Continuous Flaw Monitoring Using the Tip Diffraction Method

초음파(超音波)의 Tip Diffraction 방법(方法)을 이용한 결함연속감시(缺陷連續監視)를 위한 크기 평가(評價)

Most of significant defects in the pressure boundaries of nuclear power plant we re dispositioned to be monitored periodically every inservice inspection. Due to the difficulty of the defect sizing during operation, it is necessary to develope the continuous flaw monitoring techniques. The Tip Diffraction method, specifically speaking, spot seems to be suitable for flaw monitoring. The optimum conditions of selecting the transducer were 3.5 MHz and 45-57 degree according to compatibility with the defect height. The effective calculation of the defect height was to assume the fact that the incident beam is parallel. This method would be supplemented to ASME method about the defect characterization for the surface flaw.