A Damage-Tolerant Design and Inspection Philosophy for Nuclear and Other Pressure Vessels

Statistical analyses of pressure vessel failure rates indicate that, to date, the record is very good. However, the public hazard and environmental consequences of failure in certain industrial processes now give cause for much greater concern. With the exception of an Appendix in ASME III, the current design codes and requirements for new vessels are all based on the assumption that they are free from cracklike defects, but engineers recognize that such perfect vessels cannot be manufactured. Taking into account failure mechanisms, material properties, pre and in-service inspection, proof testing, failure statistics and probabilistic methods, views are put forward on how a damage-tolerant design and inspection philosophy may be developed to reduce further the possibility of “rogue” vessel failure.