共查询到16条相似文献,搜索用时 28 毫秒
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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. 相似文献
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反应堆压力容器是核电厂最重要设备之一,其辐照脆化状态决定了核电厂的实际运行寿命。通过借鉴国外反应堆压力容器安全评估方法,开发出一套反应堆压力容器辐照脆化时限老化分析(TLAA)的方法。该方法从上平台能量、反应堆运行压力-温度曲线及承压热冲击3个方面评价压力容器材料在正常工况和事故工况下的安全裕度。采用该方法在秦山核电厂运行许可证延续(OLE)项目中对反应堆压力容器进行了辐照脆化TLAA安全评估,其评估方法和评估结论到得国家核安全监管局的认可,为秦山核电厂延寿20 a奠定了基础。 相似文献
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本文对考虑压水堆一回路冷却剂环境对材料疲劳影响的环境疲劳修正因子Fen进行研究,结合核电厂延寿需求,确立基于环境疲劳修正因子的疲劳分析流程。针对典型接管嘴结构,采用考虑瞬态应力时间历程的应变增量方法计算转换应变率和Fen,对比了环境修正对疲劳结果的影响。考虑环境影响后,奥氏体不锈钢的疲劳使用系数增大3.2倍,低合金钢的疲劳使用系数增大8.5倍,冷却剂环境对疲劳寿命的影响显著。将考虑环境影响后的疲劳使用系数与EPRI导则的计算结果进行对比,二者计算结果接近,验证了考虑瞬态组合的环境疲劳修正因子分析计算方法的正确性。 相似文献
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反应堆压力容器老化敏感性分析方法 总被引:1,自引:0,他引:1
结合近期开展的大亚湾反应堆压力容器老化分析及大纲编写工作,归纳总结了反应堆压力容器老化敏感性分析方法,提出了较为明确的表单化的老化分析流程,可以为相关的老化分析与评价活动提供借鉴. 相似文献
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控制棒驱动机构耐压壳下部密封环应力与疲劳分析 总被引:1,自引:0,他引:1
采用有限元分析方法对某核电工程控制棒驱动机构耐压壳下部密封环的2种对接厚度进行了应力和疲劳分析对比,在疲劳分析中采用瞬态分组技术,同时参考RCC-M 2002规范对ANSYS程序中的弹塑性修正因子(Ke)进行解耦修正。结果表明,2种接头厚度的分析结果均满足RCC-M规范中的应力评定准则,其中,较薄密封环结构疲劳分析结果相对更安全,较厚密封环结构在其余工况相对更安全;在疲劳分析中对瞬态进行分组能明显降低使用系数和一次加二次应力之和幅值的保守性;在热和机械共同作用的一次加二次应力之和的幅值较高时,对Ke的修正能明显提高计算结果精度。 相似文献
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反应堆压力容器(RPV)的辐照脆化问题是核安全的重中之重,影响到核电厂的安全性、经济性与公众信心。介绍了传统RPV辐照监督方案,讨论了现行技术的局限性,梳理了RPV辐照监督无损评估技术国外研究进展与存在问题,在实验与理论研究的基础上创新性地提出了中子辐照条件下RPV钢力学性能预测统一模型,并形成了基于电磁性能的RPV辐照监督无损评估技术,进一步完善后具有较好的工程应用前景。同时指出了开展RPV钢电磁性能实验研究,既有助于从一个全新的角度理解与再认识国产RPV钢长寿期服役时的辐照脆化行为,又有利于揭示RPV钢辐照脆化机理,丰富辐照脆化的基础理论。 相似文献
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《Journal of Nuclear Science and Technology》2013,50(12):1131-1139
In this study, round robin problems for the failure probabilities of a reactor pressure vessel are solved using the probabilistic fracture mechanics code. The flaw distribution and flaw density were modified to incorporate the effects of inspection quality. Then, the impact of the inspection quality and other key parameters on the failure probability was quantitatively evaluated. The results showed that the effect of inspection quality on the failure probability has the same characteristics irrespective of the two quite different transients and the wide range of fluence level. Overall, the various inspection qualities considered in this study resulted in about an order of magnitude difference in failure probability. Additionally, it was found that the effect of warm prestressing on the failure probability depends on the characteristics of the transients. 相似文献
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《中国原子能科学研究院年报》2018,(0)
正Reactor pressure vessels are of great importance for nuclear power safety and play an extremely important role in the safe operation of reactors and in preventing nuclear leakage.As material microstructure probe,neutrons have the 相似文献
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