Measurement of PWSCC Growth Rates vs. K in the Alloy 600/182 Weld

Primary water stress corrosion cracking (PWSCC) of the Alloy 600/182 welded parts in reactor pressure vessel head penetration nozzles at pressurized water reactors has been found in many countries. It is recognized that a precise and non-destructive measurement of the crack length variation during PWSCC is necessary to properly assess the reliability/integrity of nuclear core components. In the present study, the crack growth rates (CGRs) depending on the stress intensity factor (K) of Alloy 600 base metal and the Alloy 182 weld metal around a CRDM penetration nozzle were precisely determined using a direct current potential drop method. The cracking behaviors of the Alloy 600/182 weld were also examined using various microscopic equipment