Failure Pressure and Leak Rate of Steam Generator Tubes With Stress Corrosion Cracks

This paper illustrates the use of an “equivalent rectangular crack” approach to predict leak rates through laboratory generated stress corrosion cracks. A comparison between predicted and observed test data on rupture and leak rate from laboratory generated stress corrosion cracks are provided. Specimen flaws were sized by post-test fractography in addition to pre-test advanced eddy current technique. The test failure pressures and leak rates are shown to be closer to those predicted on the basis of fractography than on NDE. However, the predictions based on NDE results are encouraging, particularly because they have the potential to determine a more detailed geometry of ligamented cracks from which more accurate predictions of failure pressure and leak rate can be made in the future.