The primary water stress corrosion cracking (PWSCC) has been detected around weld region of the control rod drive mechanism (CRDM) nozzles in nuclear power plant overseas. The CRDM nozzle was made of Alloy 600. As weld metal, Alloy 82/182 was used. Th...
The primary water stress corrosion cracking (PWSCC) has been detected around weld region of the control rod drive mechanism (CRDM) nozzles in nuclear power plant overseas. The CRDM nozzle was made of Alloy 600. As weld metal, Alloy 82/182 was used. The PWSCC can lead to leakage of reactor coolant, when it is penetrating the nozzle or weld. This paper shows the process and results of the residual life assessment of CRDM nozzle assuming PWSCC. For the study, one of domestic nuclear power plant was selected and PWSCC was postulated in that plant. Finite element analysis was performed to evaluate the stress condition around CRDM nozzle weld. The result shows that PWSCC grows rapidly and can penetrate the nozzle within few years from initiating time.