原子能科学技术2024，Vol.58Issue(4)：836-847,12.DOI:10.7538/yzk.2023.youxian.0602
基于贝叶斯估计的核电厂安全壳内压概率安全评估
Probabilistic Safety Assessment of Containment Structure under Internal Pressure Based on Bayesian Estimation
摘要
Abstract
The probabilistic safety assessment of nuclear containment under internal pressure is the key evaluation content for guaranteeing nuclear power plant safety,and the fragility assessment of the containment under internal pressure is the most crucial step in the probabilistic safety assessment of nuclear containment.At present,the inter-nal pressure fragility assessment of the containment mostly adopts the simplified lognormal distribution model,which lacks a rigorous theoretical analysis.There are multiple uncertainty issues affecting structural responses of nuclear containment in the fragility analysis and the results of the fragility analysis should be on the basis of a rigorous capacity-demand model.Meanwhile,load parameters(i.e.internal pressure)are usually used as key information to assess the internal pressure failure probability of containment.However,damage and failure of containment are more intensively correla-ted to structural response parameters(e.g.structural acceleration,structural displace-ment,and damage indices)compared with load parameters.For this reason,this paper proposed an internal pressure fragility assessment method based on Bayesian theory for nuclear containment and a form of damage ratio was used as a parameter for fragility assessment of containment.The damage ratio was realized by defining the ratio of the damage area to the full area of the containment concrete.Specifically,the fragility assessment method first established a deterministic demand model for the containment under internal pressure,and then corrected the demand model by adding correction terms.After that,Bayesian estimation was used to gradually filter the correction terms,resulting in an accurate probabilistic demand model.Finally,a fragility assessment result was obtained by establishing a limit state equation for the containment.On this basis,the probabilistic model under internal pressure was introduced to realize the prob-abilistic safety assessment of the containment,and the results of probabilistic safety assessment were compared with those of conventional fragility assessment.The results show that the cumulative containment failure probability(CCFP)of the containment decreases gradually with the increase of the damage ratio and the coefficient of variation of the CCFP is obviously smaller than that of the conventional fragility assessment method.In this paper,Bayesian estimation is introduced for probabilistic safety assess-ment of internal pressure in containment,and the damage ratio is used as a key parame-ter for fragility assessment of containment,which can provide more accurate and conser-vative results for probabilistic safety assessment of internal pressure in containment.关键词
预应力混凝土安全壳/损伤状态/贝叶斯估计/易损性评估/概率安全评估Key words
prestressed concrete containment/damage state/Bayesian estimation/fragility assessment/probabilistic safety assessment分类
核科学引用本文复制引用
田澳楠,郑志,潘晓兰,苏春阳,王勇..基于贝叶斯估计的核电厂安全壳内压概率安全评估[J].原子能科学技术,2024,58(4):836-847,12.基金项目
国家自然科学基金(51908397,52208191) （51908397,52208191）
山西省应用基础研究计划面上青年基金(201901D211025) （201901D211025）
山西省回国留学人员科研资助项目(2023-085) （2023-085）
