主给水管道破口尺寸对CPR1000二次侧非能动应急热阱事故缓解能力影响研究

在主给水管道破裂事故下，针对不同破口面积，利用RELAP5/MOD3.4程序对CPR1000压水堆一回路和二次侧非能动应急热阱的主要热工水力参数瞬态特性进行分析计算，验证采用CPR1000二次侧非能动应急热阱对事故的缓解能力和不同破口面积对主要参数的影响。结果表明：CPR1000在发生主给水管道破裂事故后，二次侧非能动应急热阱可及时向蒸汽发生器补水，同时导出堆芯余热，保证反应堆处于安全状态，随着破口面积的增大，初始时刻一回路压力和温度升高更快，随着二次侧非能动应急热阱的投入，压力和温度又迅速降低，说明CPR1000二次侧非能动应急热阱在文中所研究的破口面积范围内可非常有效地缓解事故。

Analysis of Secondary Emergency Passive Heat Sink's Ability to Relieve Accident of CPR1000 With Different Main-Feedwater Line Break Area

The transient thermal hydraulic characteristics of CPR1000 were analyzed using RELAP5/MOD3.4 code to verify the ability of the adopting water-cooled heat exchanger’s emergency passive heat sink system(WEPHS) for accident mitigation under the condition of feed water line break(FLB) with different break area.The calculation results show that the WEPHS of CPR1000 can supply the water to steam generator immediately and remove the core residual heat after the FLB successfully.With the broken area increasing,the pressure and temperature of the primary loop increase higher,and decrease more sharply with the WEPHS operation.It also shows that the design of WEPHS of CPR1000 is effective.