CAJ | 학술논문

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。
재함결함결구완정성평정중，즉사만족학정성분석요구，결구야회존재발생실효적가능。제출학정성결함험수준칙소대응실효개솔적분석방법，이계산재만족학정성분석요구적림계조건하결구적실효개솔。채용해방법가이험증학정성결함험수준칙시부능구만족결구적개솔요구，야가의거개솔요구지도학정성결함험수준칙중안전계수적제정。침대ASME BPVC제XI권중기우응력강도인자적결함험수준칙，이정상강온공황화승압열충격사고공황위례，대일전형함결함반응퇴압력용기(Reactor pressure vessel, RPV)진행학정성분석화개솔분석，득도상응공황하적림계렬문척촌급실효개솔，병토론안전계수대함결함RPV실효개솔적영향。소분석안례표명，ASME표준중규정적안전계수재정상강온공황하상불능보증RPV림계실효개솔저우핵안전적개솔요구。
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.