Tests on Mock-ups Representative of Rolling Zones of Steam Generator tubes in High Temperature Hydrogenated Water

摘要

Primary Water Stress Corrosion Cracking (PWSCC)of Alloy 600 in PWRs led vendors to replace several keycomponents such as steam generator (SG) tubes. Despitethe outstanding operational experience, some concernswere raised on the potential SCC susceptibility of Alloy690 TT. The present paper deals with the results of a longterm study of the resistance to PWSCC of mock-upsrepresentative of the roll transitions of SG tubes close tothe tubesheet, comparing the performance of Alloys 690and 600 up to 100 000 h in high temperaturehydrogenated water at a temperature of 360°C.