风险指引的CPR1000核电厂LBLOCA分析方法初步研究

随着核电厂安全分析方法的不断发展，结合传统确定论分析与概率风险评价（PSA）的风险指引型安全分析方法逐渐引起安审当局和核电业主的广泛关注。本文基于国际上风险指引型分析方法在其他领域的应用现状，提出了风险指引的大破口失水事故（LBLOCA）分析方法，并重新评估了CPR1000核电厂的堆芯燃料包壳峰值温度（PCT）裕量。在PSA分析中，识别并量化了LBLOCA发生后可能发生的162个事件序列，并采用确定论现实分析方法（DRM）对筛选出的18个概率较大的事件序列进行了计算分析。然后通过期望值评估法和特定序列覆盖法对LBLOCA的PCT裕量进行了评估。结果表明，本文方法下LBLOCA的PCT裕量约为36~55 ℃，相比于传统的DRM裕量提升了16~35 ℃。

Preliminary Study on Risk-informed LBLOCA of CPR1000 Nuclear Power Plant

With the development of the safety assessment approach of nuclear power plants (NPPs), a risk-informed analysis methodology combining traditional deterministic methodology and probabilistic safety assessment (PSA) has aroused a widespread concern in nuclear safety authorities and nuclear power plant owners. Following the international application of risk-informed analysis methodology, the framework of risk-informed large break loss of coolant accident (LBLOCA) was proposed, and the peak cladding temperature (PCT) margin of CPR1000 nuclear power plant was re-evaluated in this paper. In the PSA analysis, 162 probabilistic sequences were identified and quantified after LBLOCA occured. Then 18 probabilistically significant sequences were selected for the deterministic methodology analysis with deterministic realistic method (DRM). Then the risk-informed PCT margin was evaluated by two different methods, namely the expecting value estimation method and the sequence probability coverage method. The results show that the PCT margin evaluated by the risk-informed LBLOCA is about 36-55 ℃, which is greater than that of the DRM by 16-35 ℃.