In the described series pump arrangement, from which source does the residual heat removal pump take suction?

• A. Containment Pumps
• B. Feedwater Pumps
• C. Condensate Return
• D. Sump Basin

Answer: (A)

In a series pump arrangement, the downstream pump takes suction from the discharge of the upstream pump. Here, the residual heat removal pump is placed after the containment pumps, so it draws its suction from the discharge line of those containment pumps. Water is first pumped by the containment pumps and then fed into the residual heat removal loop, which is why the suction source is the containment pumps’ discharge. The other sources would apply if the pumps were not arranged in series, but with this configuration the series flow dictates suction from the previous pump’s output.