CRACK STABILITY CRITERIA IN STEAM GENERATOR TUBES

ABSTRACT The safety assessment function of the steam generator tubes in French PWRs greatly relies on the leak-before-risk-of-break concept, which must forestall any risk of tube bursting irrespective of operating conditions. The examination of this concept led EdF and FRAMATOME to set up and implement an extensive theoretical and experimental program, with the aim of evaluating the margins available for steam generator tubes with respect to break risks, for the leakage allowing which should precede a rupture during normal operation.