During Refueling Outage 18 (RFO18, April 2011) Pilgrim Nuclear Power Station (PNPS) identified crack-like indications on the Steam Separator Lifting Lugs. A multi-disciplinary engineering effort was undertaken to determine the cause of the cracking and prepare the technical justification for long term operation of the lifting lugs. This approach focused on addressing the potential for future degradation due to the existing indications, and the resulting effects on the hardware and its function. A materials evaluation concluded that intergranular stress corrosion cracking (IGSCC), most likely associated with cold work present in the as-fabricated steam separator, was the cause of the indications found on the lifting lugs. To support long term operation of the lifting lugs at PNPS, a structural evaluation was completed using ANSI N14.6 and NUREG-0612 criteria with a conservative bounding configuration. Crack growth rates, based on BWRVIP-76 guidance of 5E-5 in/hr for length and 2.2E-5 in/hour for depth, were used in the analyses. The evaluation concluded that PNPS could continue with long term operation of the Steam Separator. Consistent with standard practice, a general heavy loads examination was performed in 2013 (RFO19), confirming no discernable changes. The general examination will be repeated in 2015 (RFO20), and an examination of the lifting lugs is planned for the 2017 Refueling Outage (RFO21) to confirm that the indication behavior is consistent with the evaluation results.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.