During natural circulation, what is true about steam generator pressures?

• A. Stable or decreasing
• B. Increasing
• C. Uncertain
• D. Unchanged

Answer: (A)

During natural circulation, there is no pump forcing more flow or higher pressure. The loop relies on buoyancy from density differences, and the steam generator pressure is set by the balance between heat input and steam removal in the condenser. Without an external driver to push more steam or increase flow, the pressure in the steam generator tends to settle at a steady level or fall as cooling and steam removal change. That’s why the correct statement is that the steam generator pressures are stable or decreasing.