Pump Behavior and Its Impact on a Loss-of-Coolant Accident in a Pressurized Water Reactor

The impact of a loss-of-coolant accident (LOCA) on a nuclear reactor is determined in its first phase by many events, one of them being the behavior of the reactor coolant pumps. In this case, a mixture of steam and water flows through the pumps. Experiments were carried out to examine the family of characteristics of geometrically scaled pumps (scale 1:5 and 1:4) within the relevant parameter range under such conditions. The presented results of steady-state experiments are compared with results of former projects. Besides flow and speed, the most significant parameters on two-phase pump performance are void fraction and system pressure. A brief comparison between steady-state and transient results is provided. The impact of the pump’s behavior on the LOCA is demonstrated on the basis of blowdown calculations using various pump models and two-phase pump data.