AP1000核电厂ATWS事故分析

ATWS Accident Analysis for AP1000 Nuclear Power Plant

对美国三代核电厂(AP1000)所有未能紧急停堆的预期瞬态(ATWS)进行分析,确定失去正常给水ATWS为最极限的ATWS。通过敏感性分析对多样化驱动系统(DAS)控制保护逻辑进行改进:蒸汽发生器(SG)宽量程低水位触发蒸汽旁排隔离及堆芯补水箱(CMT)动作,并立即停运主冷却剂泵(RCP)。按照改进后的DAS逻辑进行最终工况分析,结果表明:在整个电厂寿期内,考虑最极限的慢化剂温度系数(MTC),失去正常给水ATWS的反应堆冷却剂系统(RCS)峰值压力满足验收准则,且有较大的裕度。

?According to the analysis of all the anticipated transients without scram(ATWS) for AP1000 plant,it was determined that the loss of normal feedwater ATWS event is the limiting ATWS.Based on several sensitivity studies,the diverse actuation system(DAS) was improved as follow:low SG wide range water level setpoint implement the steam dump isolation and CMTs actuation,and then trip the RCP immediately.The final cases have been analyzed assuming the new DAS ATWS protection logic,and the results of analysis show that:considering the limiting MTC for the whole AP1000 plant life,the RCS peak pressure of LNFW ATWS meets the acceptance criteria with considerable margin.