本构模型不确定性评价结构化方法开发及应用  

Development and Application of Structural Method for Uncertainty Evaluation of Constitutive Models

作　　者：熊青文 苟军利[2] 杜鹏 邓坚[1] 刘余[1] 陈伟[1] 党高健[1] Xiong Qingwen;Gou Junli;Du Peng;Deng Jian;Liu Yu;Chen Wei;Dang Gaojian(Science and Technology on Reactor System Design Technology Laboratory,Nuclear Power Institute of China,Chengdu,610213,China;School of Nuclear Science and Technology,Xi’an Jiaotong University,Xi’an,710049,China)

机构地区：[1]中国核动力研究设计院核反应堆系统设计技术重点实验室,成都610213 [2]西安交通大学核科学与技术学院,西安710049

出　　处：《核动力工程》2022年第4期147-153,共7页Nuclear Power Engineering

摘　　要：最佳估算加不确定性(BEPU)方法被国际原子能机构(IAEA)推荐用于核电厂安全分析,目前已成为核电厂执照申请的主流方法。典型BEPU方法依赖于最佳估算程序将输入参数的不确定性传播至输出,而程序本构模型的不确定性则往往没有得到适当考虑。本研究提出了一种结构化方法用于评价程序本构模型的不确定性,基于该方法对本构模型按照特征进行分类,针对不同模型类型采用不同评价方法。本研究使用的模型评价方法包括前向方法中的非参数曲线估计法以及反向方法中的贝叶斯校准法和覆盖率校准法,此外还包含替代模型的构建方法。使用该结构化方法量化了失水事故中重要模型的不确定性,并将量化的模型不确定性通过抽样计算传播至包壳峰值温度。结果表明,抽样计算值和实验值均小于保守计算值,考虑了模型不确定性后的传播计算结果能够很好地包络实验值,且考虑模型不确定性后能够有效增加安全裕量。The best estimate plus uncertainty(BEPU)analysis is recommended by IAEA for safety analysis of nuclear power plants,and has become the mainstream method for license application of nuclear power plants.Typical BEPU method relies on the best estimation program to propagate the uncertainties of input parameters to the output,while the uncertainties of the program constitutive model are often not properly considered.In this study,a structural method is proposed to evaluate the uncertainties of program constitutive model.Based on this method,constitutive models are classified according to characteristics,and different evaluation methods are adopted for different model types.The model evaluation methods used in this study include the non-parametric curve estimation method in the forward method and the Bayesian calibration method and coverage calibration method in the reverse method,as well as alternative model construction methods.The structural method is used to quantify the uncertainties of important models in LOCA,and the quantified model uncertainties are transmitted to the peak cladding temperature through sampling calculation.The results show that both the sampling calculation values and the experimental values are smaller than the conservative calculation value,and the propagation calculation results after considering the model uncertainties can well cover the experimental values,and the safety margins can be effectively increased after considering the model uncertainties.

关 键 词：本构模型 结构化方法 非参数曲线估计 贝叶斯校准 不确定性量化 

分 类 号：TL364[核科学技术—核技术及应用]