在含缺陷结构完整性评定中，即使满足确定性分析要求，结构也会存在发生失效的可能。提出确定性缺陷验收准则所对应失效概率的分析方法，以计算在满足确定性分析要求的临界条件下结构的失效概率。采用该方法可以验证确定性缺陷验收准则是否能够满足结构的概率要求，也可依据概率要求指导确定性缺陷验收准则中安全系数的制定。针对ASME BPVC第XI卷中基于应力强度因子的缺陷验收准则，以正常降温工况和承压热冲击事故工况为例，对一典型含缺陷反应堆压力容器(Reactor pressure vessel, RPV)进行确定性分析和概率分析，得到相应工况下的临界裂纹尺寸及失效概率，并讨论安全系数对含缺陷RPV失效概率的影响。所分析案例表明，ASME标准中规定的安全系数在正常降温工况下尚不能保证RPV临界失效概率低于核安全的概率要求。

The accepted defective components using a deterministic approach in structural integrity assessment may still fail under the operation conditions used in the assessment. A probability analysis method is proposed in this paper to estimate the failure probability of the defective components corresponding to the critical conditions of the deterministic assessment method. The method not only can be used to validate the probabilistic requirement under the deterministic assessment criteria, but also guide to draft the safety factors in the deterministic assessment criteria based on the probabilistic requirement. Considering elastic fracture mechanics based flaw acceptance criteria given in ASME BPVC Section XI, a typical cooling down transient (normal operation) and a typical pressurized thermal shock transient(a fault condition) are analyzed using both the deterministic and probabilistic methods for a reactor pressure vessel(RPV) with defects. The critical crack sizes are calculated using the deterministic method with assigned safety factors and the corresponding failure probabilities are estimated. Then, the effect of the safety factor on the failure probabilities is discussed. The results of the case study show that the safety factors recommended by ASME Code may not be sufficient for the normal cooling down transient to satisfy the probabilistic requirement of nuclear safety.