Redundancy and a shared power source

A fictional safety-design discussion presents two pumps intended to perform the same cooling function. Both pumps depend on one unprotected electrical supply and one environmental location. The supplied scenario states that a single flooding event can disable that supply and both pump controls. A trainee multiplies two independent component failure probabilities and says simultaneous loss is effectively impossible. No independence evidence, alternate supply or environmental qualification is provided. Students must identify the difference between duplicate equipment and demonstrably independent provisions and explain what the shared event changes in the model. The case is a design-reasoning exercise and supplies neither an actual plant vulnerability nor instructions for altering or operating a nuclear system.