Behaviour of a PWR vessel dissimilar metal weld during a steam line break transient

This paper presents the results of a Finite Element analysis conducted on t he behaviour of a 15 mm. deep fully circumferential crack on the outer surf ace of a bi-metallic weld of a 900 MWe Pressurized Water Reactor vessel, du ring a Steam Line Break transient. The typical weld considered connects the stainless-steel hot leg with the ferritic vessel. This work is part of a Benchmark exercise organised in the framework of an European Commission (DG Environment) project on Transition Welds. However, the results presented here concern only those obtained at Framatome using S YSTUS + code and deal with the thermo-mechanical analysis, the evaluation o f the crack driving energy (J-integral) and a discussion on crack stability . These results are compared with those obtained using a simplified method developed earlier and presented at one of the international conferences. (C ) 2001 Elsevier Science B.V. All rights reserved.