PREDICTING CRACK ARREST IN A NUCLEAR-REACTOR PRESSURE-VESSEL DURING A HYPOTHETICAL PRESSURIZED THERMAL-SHOCK EVENT

The paper uses a dynamic analysis based on the reflectionless stress intensity factor procedure to predict crack arrest in a nuclear reactor pressure vessel that is subjected to a pressurized thermal shock event. For the case in which an initially shallow crack propagates deep into the thickness of the vessel, the procedure predicts a crack jump length that is significantly less than the jump length predicted via the ASME Code KIa procedure. This prediction is in accord with the general conclusions arising from a procedure, recently developed by Combustion Engineering, which predicts crack arrest on the basis of a static analysis, and assumes that during the propagation event the surface to which the crack propagates is restrained from moving in the crack propagation direction. The results from the present paper's analysis therefore supports the Combustion Engineering view that, when a shallow crack arrests deep in the thickness of a vessel, the currently accepted. ASME Code procedure is overly conservative in its prediction of crack arrest. © 1990.