Evaluation of the probability of a leak in the flange joint of a steam-generator collector cover as a result of stud failure

A two-stage approach to evaluating the probability of leak appearing in the flange joint as a result of a failure of the securing studs is described. First the probability of only one stud failing is calculated. This probability depends on, specifically, the integrity of all other studs. The probabilities of different combinations of the relative arrangements of whole and failed studs are calculated at the second stage. The method is illustrated for the calculation of the probability of a leak in the region of the collector cover for a PGV-1000 steam generator. Normative data on the strength and mechanical characteristics of the structural materials and loads corresponding to the nominal operating regimes are used in the calculations.[PUBLICATION ABSTRACT]