Evaluation of Passive Safety Injection System Performance Under Large Break LOCA for Qinshan PWR

In this work, a brand new passive safety injection system has been designed for the ocean-based Qinshan Phase I nuclear power plant to update and replace traditional active ones. The is made up of high pressure, medium lower pressure system, two-stage automatic depressurization system. To evaluate performance, double-ended cold leg large break LOCA analyzed by best-estimated analysis RELAP5 code. main operation parameters such as primary safe mass flow rates, core water level, peak cladding temperature have presented. results conclude that can act similar AP1000, which assure sufficient cooling keep reactor covered under most severe LBLOCA condition.