Evaluation of analysis methods for prevention of catastrophic failure in pressure vessels

Considerable safety margins may exist in ductile structures like reactor pressure vessels even in presence of deep cracks. Safety assessments for such vessels can always be performed using full 3D FEM analysis but the cost may become unacceptably large. Therefore, today also a number of different engineering analysis methods for such assessments is available. Examples of such methods are R6 and more advanced FAD methods, Kiefners methods and crack driving force diagrams in accompanion to EPRI Handbook formulae or perhaps even 2D FEM. The accuracy of different engineering assessment methods is most appropriately evaluated by carparing the results calculated using these methods with those from experiments.