Experimental and numerical study on the burst pressure of steam generator tubes with L- and U-type through-wall combination cracks

Abstract

Several nuclear power plants have reported that they often experience through-wall combination cracks consisting of longitudinal and circumferential cracks in the steam generator tubes. In this study, L- and U-type through-wall combination cracks in a steam generator tube were evaluated using the crack opening angle (COA) in an elastic-plastic analysis. The calculated burst pressures were also compared with the experimental results. In the procedure, the stress intensity factor (KI) in elastic analysis was reviewed to validate COA as an appropriate fracture parameter for the burst pressure of longitudinal through-wall cracks and T-type through-wall combination cracks. From the results, an appropriate length-based burst criterion by using COA can be used for a structural integrity assessment for the through-wall combination cracks in steam generator tubes.