MINIMIZING CORROSION is a primary objective of nuclear power plant design. Such plants use corrosion-resistant alloys and high purity and well controlled water chemistries in critical systems to achieve that objective. Despite such measures, nuclear plants have experienced localized corrosion and environmentally assisted cracking in several plant components. These corrosion events have had significant ramifications on plant operability due to the extremely stringent requirements on component reliability and containment of radio-nuclides. Standards devoted to assessing susceptibility to localized corrosion and stress-corrosion cracking (SCC) have been used to qualify materials and remedial countermeasures. In many cases, the evolution of nuclear plant designs has required development of new standards.