基于风险指引方法的“华龙一号”运行技术规格书后撤状态优化研究

Research on HPR1000 Operation Technical Specification Endstate Optimization Based on Risk Informed Method

结合风险指引型方法对国内核电厂运行技术规格书开展优化工作是目前国内、外研究的热点,机组后撤状态优化难度较大,国内尚无应用。本文以“华龙一号”(HPR1000)首堆为例,采用风险指引型方法对后撤状态优化关键技术进行了研究,包括不同停堆工况下风险定性、定量评价方法。以一列安全注入系统不可用时的后撤状态为例进行了详细分析,结果表明,双相中间停堆工况RHR运行条件(RHR隔离)是最为安全的停堆状态,该状态可用设备更多,始发事件更少,机组总体风险更低,也满足纵深防御、安全裕度等要求。机组后撤状态优化后,减少了操作员操作负担,机组发生设备故障导致非计划停运时,可以减少停运时间12.5 h以上。

The optimization of operation technical specifications combined with risk informed methods is a hot research topic at home and abroad.The study of unit endstate is a difficult issue,and has no application at home.The key technologies of HPR1000 endstate optimization is studied by using the risk informed methods,including qualitative and quantitative risk assessment methods under different endstate.The endstate of one RSI train inoperable is analyzed in detail.Research shows that MODE 3c(Biphasic intermediate shutdown,RHR conditions(RHR not connected)is the safest endstate with more usable equipments,less initial events,lower overall risk,and satisfies the requirements of defense in depth,and safety margins.The operator’s burden is reduced after the endstate optimization,and the unit shutdown time is reduced more than 12.5 hours in case of unplanned shutdown due to equipment failure.