CPR1000全厂断电叠加小破口失水事故下一回路外部注水策略分析

Analysis of primary system external water injection strategies of station blackout along with small break loss-of-coolant accident for CPR1000

严重事故管理导则(SAMGs)是目前缓解核电站严重事故进程的主要依据,而对反应堆一回路进行卸压和注水是严重事故下保证堆芯冷却最常用的策略,但是目前的SAMGs对于外部注水策略并没有给出具体的操作指导.为此,以我国目前广泛应用的CPR1000核电站作为研究对象,以全厂断电叠加小破口失水事故作为基础事故序列,采用模块化严重事故分析程序对其进行建模,并对一回路外部注水策略进行了详细分析.结果表明,根据不同外部注水时间采取合适的卸压速率及注水流量可有效缓解事故进程,使堆芯冷却,防止压力容器失效及大量放射性物质外泄.该研究成果可为完善CPR1000核电站SAMGs中外部注水的具体措施以及核电厂类似事故序列的培训课程提供参考.

Severe accident management guidelines(SAMGs)is the key guidance for alleviating severe accidents in nuclear power plants.Among them,depressurization and water injection for the primary coolant system are the most commonly used strategies to ensure core cooling.However,the current SAMGs have not provided specific operational guidance for external water injection strategy.Thus,in this paper,based on the commonly used CPR1000 nuclear power station in our country,and using station blackout along with small break loss-of-coolant accident as basic accident sequence,a model is established using a modular severe accident analysis code and the external water injection strategies of the primary system is detailedly analized.The results show that proper depressurized rate and water injection flow rate based on different external water injection time can effectively alleviate the process of accident,cool the reactor core,and prevent the failure of pressure vessel and the release of a large amount of radioactivity.The results of this study can provide references for improving specific measures of external water injection in SAMGs of CPR1000 nuclear power station and for the training courses of similar accident sequences in nuclear power plants.