CPR1000核电厂乏燃料水池重力补水的有效性分析

Analyse of the Efficiency of Gravity Makeup from SFP in CPR1000 Nuclear Power Plants

CPR1000核电厂维修冷停堆工况下如发生全厂失电,汽动辅助给水泵等不依赖动力电源的设备不再可用,将增加了堆芯损坏的风险。设计可利用乏燃料水池和一回路之间的水位差可实现向堆芯的重力补水。本文对影响乏燃料水池重力补水效率的现象进行了分析,并进行建模计算。结果表明,在维修冷停堆工况下,在安全壳未打开条件下,安全壳内压力的升高是降低重力补水效率的主要因素;在最不利的工况下,从乏燃料水池通过重力向一回路补水确保至少在2.7小时内堆芯不会裸露。

Considering the Station Black Out in the condition of maintenance cold shutdown（ MCS） in CPR1000 nuclear power plants,the equipments independent of power source,such as the turbine auxiliary feedwater pump,are not usable anymore,this increase the risk of core damage. Makeup by gravity is practical to inject water into the core depending to the height difference between spent fuel pool（ SFP）and primary loop. The phenomena which may impair the efficiency of gravity makeup from SFP are analyzed and modeled. The result show that if the containment is closed in MCS,the pressure rise in the containment is the main reason of decreasing the efficiency of gravity makeup,and even in the worst condition,the gravity makeup from SFP will ensure the core keeping covered within at least 2. 7 hours.