反应堆压力容器疲劳时限老化分析研究

Analysis of Fatigue Time Limit Aging of Reactor Pressure Vessels

基于美国核管会(U.S.NRC)的管理导则RG1.207提出的2种考虑冷却剂环境对设备疲劳寿命的影响评估办法,对比了美国NUREG/CR-6909和日本JNES两大体系不同环境疲劳修正因子(Fen)表达式和边界条件对环境疲劳的影响,对比了Fen和环境疲劳曲线2种分析方法对环境疲劳寿命评估的差异。最后,将考虑应变率历程的详细Fen方法、环境疲劳曲线方法、参数保守取值的Fen方法3种方式都应用于某核电厂反应堆压力容器进口接管嘴部位的疲劳评定中。结果表明,相比环境疲劳曲线的方法和参数保守取值的Fen计算方法,考虑应变率历程的详细Fen方法能更准确评估结构的环境疲劳寿命。

Based on two methods of evaluating the influence of the coolant environment on the fatigue life of equipment proposed by U.S.NRC in the management guideline RG1.207,the effects on different environmental fatigue correction factor(Fen)expressions and boundary conditions were compared between the NUREG/CR-6909 of USA and JNES of JAPAN.The difference of the environmental fatigue life assessment between environmental fatigue correction factor and environmental fatigue curve was also analyzed.Finally,the three methods were adopted in the analysis of the reactor pressure vessel inlet nozzle fatigue assessment.The methods are Fen method considering strain rate history,environmental fatigue curve method and the Fen method using conservative parameters.The results show that,compared with other two methods,the Fen method considering strain rate history can evaluate the environmental fatigue life of structures with higher accuracy.