Analysis of CAP1400 Reactor Coolant Hot Leg Flow Field

The CAP1400 reactor coolant main pipe plays a very important role in the plant safety operation, as it transports coolant among the Reactor Vessel, the Steam Generator and the Reactor Coolant Pumps, simultaneously connects the main equipments. The flow resistance of CAP1400 coolant main pipe is calculated by classic flow resistance calculation formula at present, but a big tolerance would be caused by the big size, complex structure and multi system/ instruments interfaces of the main pipe. Otherwise, CAP1400 Reactor Coolant System employs elbow flow instrument to measure coolant flowrate, the big size piping nozzle like ADS 4th and surge line might influence the stability of flow field, which affects the accuracy of the elbow flow instrument. A CFD software STAR-CCM+ is used to model CAP1400 main pipe hot leg in this paper and analyze the detailed flow field to obtain more precise calculation results, and verify if the elbow flow instrument arrangement is reasonable.