Which statement describes a primary purpose of reactor chemistry control?

Which statement describes a primary purpose of reactor chemistry control?

• A. Increase fuel burnup
• B. Change coolant color
• C. Enhance thermal conductivity
• D. Protect reactor coolant system pressure boundary

Answer: (D)

The main goal of reactor chemistry control is to protect the reactor coolant system’s pressure boundary by keeping the coolant chemistry within tight ranges to minimize corrosion and material degradation. When the chemistry is properly managed—adjusting pH, controlling dissolved oxygen or hydrogen, and limiting corrosive species—the metal surfaces that form the boundary between the reactor and coolant are less prone to corrosion, cracking, or the formation of corrosion products that can deposit as CRUD. This preserves the integrity of pipes, vessels, and heat exchangers, reduces the risk of leaks, and supports safe, reliable operation of the reactor. Other options don’t address this protective function. Increasing fuel burnup relates to how efficiently fuel is used, not to protecting the boundary via chemistry. Changing coolant color isn’t a meaningful or primary control parameter, and enhancing thermal conductivity is more about basic coolant properties or design than a primary chemistry control objective.

The main goal of reactor chemistry control is to protect the reactor coolant system’s pressure boundary by keeping the coolant chemistry within tight ranges to minimize corrosion and material degradation. When the chemistry is properly managed—adjusting pH, controlling dissolved oxygen or hydrogen, and limiting corrosive species—the metal surfaces that form the boundary between the reactor and coolant are less prone to corrosion, cracking, or the formation of corrosion products that can deposit as CRUD. This preserves the integrity of pipes, vessels, and heat exchangers, reduces the risk of leaks, and supports safe, reliable operation of the reactor.

Other options don’t address this protective function. Increasing fuel burnup relates to how efficiently fuel is used, not to protecting the boundary via chemistry. Changing coolant color isn’t a meaningful or primary control parameter, and enhancing thermal conductivity is more about basic coolant properties or design than a primary chemistry control objective.