A detailed BWR recirculation loop model for RELAP

- A new detailed BWR recirculation loop model was developed for RELAP.
- All jet pumps, risers, manifold, suction and control valves, and recirculation pump are modeled.
- Model is tested against data from partial blockage of two jet pumps.
- For practical applications, simulation results showed good agreement with available data.

A new detailed geometric model of the whole recirculation loop of a BWR has been developed for the code RELAP. This detailed model includes the 10 jet pumps, 5 risers, manifold, suction and control valves, and the recirculation pump, per recirculation loop. The model is tested against data from an event of partial blockage at the entrance nozzle of one jet pump in both recirculation loops. For practical applications, simulation results showed good agreement with data. Then, values of parameters considered as figure of merit (reactor power, dome pressure, core flow, among others) for this event are compared against those from the common 1 jet pump per loop model. The results show that new detailed model led to a closer prediction of the reported power change. The detailed recirculation loop model can provide more reliable boundary condition data to a CFD models for studies of, for example, flow induced vibration, wear, and crack initiation.