Development of Sizing Technique for Axial ODSCC in Steam Generator Tubes

It is necessary to evaluate the depth and length of the crack in steam generator tubes in order to complete the condition monitoring and the operational assessment of the Steam Generator Management Program. Various methods have been used to size crack indications from eddy current data during the in-service inspection in nuclear power plants. However, sizing results have had uncertainties due to its difficulty and ambiguity. Many trials to develop crack-sizing techniques have been made in many countries. The qualified technique has not been developed yet. KEPRI (Korea Electric Power Research Institute) has been developing crack-sizing techniques by utilizing Kori Unit 1 Retired Steam Generators (RSG). The crack-sizing technique for axial ODSCC (Outside Diameter Stress Corrosion Cracking) has been developed by KEPRI through the round robin tests. The developed technique can be used in the Steam Generator Management Program after being qualified by the peer review process