Research on Dimension Calculation of CPR1000 Safety Injection System High-pressure Restriction Orifices

This paper starts from the basic principle of throttle orifice pipe. Based on the flow capacity test data of safety injection system of the 4th unit in Ling’ao Nuclear Power Plant Phase II, and by the calculation with classical fluid mechanics formulation, the theoretical results of the size for the throttle orifice are obtained, which are similar with the actual installation data, therefore, this test result can provide feasible plan for the size calculation of high pressure throttle orifice in the CPR1000 safety injection system.