Prediction of Creep Rupture of Pressure Vessels

Predictions of creep rupture of a reactor pressure vessel in a severe hypothetical accident needs to accurately take into account the interactions between creep and damage phenomena. This paper presents an approach based on a model coupling elasto-visco-plasticity and damage, formulated within the framework of continuous damage theory. The model and its implementation in a finite element software are presented and special attention is devoted to the procedure enabling the identification of the parameters of the model. The approach is validated on two tests of the program RUPTHER which concerns A508 cl3 steel cylinder and on the EC-FOREVER experiment (A533 steel mockup) developed as part of the European Commission Program Assessment of Reactor Vessel Integrity.