Which corrosion type is a concern for leak conditions in a nuclear reactor system due to boron content in coolant?

• A. Crevice corrosion
• B. Impurity
• C. Bor ic acid corrosion
• D. Flow accelerated corrosion

Answer: (C)

Boron in reactor coolant exists as boric acid in the borated water. When a leak occurs, boric acid can concentrate at the leak site and create a localized, corrosive environment that attacks the metal surfaces of reactor components (often stainless steel and nickel-based alloys). This makes boric acid corrosion the concern for leak conditions, since it directly ties the presence of boron in the coolant to chemical attack and potential leaks.

Crevice corrosion relies on stagnant solution in tight gaps, which isn’t specifically driven by boron content. Impurity corrosion is a broader category tied to general impurities rather than boron chemistry. Flow accelerated corrosion is about oxide dissolution due to high-velocity flow and is not unique to boric acid chemistry.