As summarized in a recent review by Garnsey1 , certain designs of steam generator (s.g.) used in pressurized water reactors (PWR's) have been subject to a variety of serious corrosion problems. Although pitting corrosion of s.g. tubes or internals is not in the forefront of these difficulties, it remains a cause of concern, since ingress of cooling water into the secondary circuit as a result of condenser leakage may lead to the presence of chloride-containing species in the s.g. water. In KWU practice, stringent control of secondary water chemistry means that attack of this kind would not be expected, but the extent of the safety margin involved is difficult to assess in view of the scarcity of data on the pitting resistance of s.g. materials in high-temperature water containing low levels of chloride. The present work was thus undertaken in an attempt to quantify the pitting behaviour of three alloys commonly used in s.g. construction in solutions simulating faulted PWR secondary water at near-operating and intermediate temperatures.
