Corrosion tests were performed on 12 test vessels. Two sets of model heat exchangers a set consists of a steam generator and superheater and eight miniature heat exchangers were tested dynamically in a pressurized water loop. One set of model heat exchangers had bimetal tubes stainless steel in the primary, carbon steel in the secondary and the other had Inconel tubes. The set with bimetal tubes was service tested for 4890 and that with Inconel tubes was service tested 4747 hr. The secondary environment in the bimetal vessels simulated the SM-1 water conditions while the secondary in the Inconel vessels simulated reactor quality water. The Inconel, nickel and Monel tubing performed well in both reactor grade and high chloride secondary water. The Inconel tubing in the model vessels exposed to reactor grade water did not pit. The bimetal model vessels which were tested using reactor grade water showed the degree of pitting was prohibitive for long-life steam generators. Tubing in one of the bimetal miniature vessels was defected to expose stainless steel to the high chloride secondary environment no cracking of the stainless sublayer occurred.