What is the purpose of coatings or liners in protecting reactor components from flow-assisted corrosion?

• A. To provide a barrier to corrosion and reduce wear and hydrogen ingress
• B. To improve electrical insulation
• C. To increase heat transfer
• D. To reflect neutrons

Answer: (A)

Coatings and liners protect reactor components by acting as a barrier between the metal surface and the flowing coolant. Flow-assisted corrosion combines chemical attack with mechanical wear from high-velocity flow, so a protective layer reduces direct contact with the corrosive environment and slows or prevents oxide dissolution on the metal. A good coating also smooths or hardens the surface, lowering erosive wear from the fast-moving fluid and particles. In addition, many coatings limit hydrogen ingress into the metal, helping prevent hydrogen embrittlement and related degradation.

This approach requires the coating to be chemically compatible with the coolant, withstand high temperature and radiation, maintain strong adhesion, and remain intact under flow conditions. So, the primary purpose is to provide a barrier to corrosion and reduce wear and hydrogen ingress. Electrical insulation, enhanced heat transfer, or reflecting neutrons are not the aims of coatings used specifically to guard against flow-assisted corrosion.