A series of autoclave corrosion tests were conducted to simulate conditions in the steam generator. Nal-Prep III, a commercial passivating treatment, produced only slight reduction in the pitting rate on carbon steel. Type 316 stainless steel and more highly alloyed stainless steels showed no or low pitting and no stress corrosion cracking in the steam generator conditions. Alloys with low or no molybdenum such as Type 304 showed some pitting at the liquid-vapor interface. Electrochemical tests suggest that eliminating the caustic 94D4 wash water from the bottoms water may decrease pitting in the steam generator tubes.
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