PITTING AND ITS PROTECTION OF STEAM GENERATOR TUBES IN NUCLEAR POWER PLANTS

Pitting is a type of localized corrosion resulting in penatration of steam generator tubes.Pitting is often a precursor of stress corrosin cracking leading to frequent unforeseen shutdown.The measures used to prevent pitting include selection of heat transfer tube material,secondary side water chemical impurity control,cleaning of sludge on the tubesheet and tube bundle and nondestructive testing of heat transfer tubes.