European THERFAT project - thermal fatigue evaluation of piping system "Tee"-connections
European THERFAT project - thermal fatigue evaluation of piping system "Tee"-connections
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DOI：
10.1016/j.nucengdes.2004.08.041
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发表时间：
2005-02-01
影响因子：
1.7
通讯作者：
Wilke, U
中科院分区：
文献类型：
--
作者：
Metzner, K;Wilke, U
热疲劳是核电站中一种重要的长期退化机制。特别是，随着运行的设备变得更老，寿命延长活动开始。运营商和监管机构需要筛选标准，以排除热疲劳的风险和方法，以确定显着的疲劳相关性。一般来说，常见的热疲劳问题是很好地理解和控制的工厂仪表在疲劳敏感的位置。然而，一些事故表明，某些管道系统三通容易受到湍流温度混合效应的影响，而普通热电偶仪表无法对其进行充分监测。因此，一个关于管道系统T形接头热疲劳评估的欧洲项目THERFAT已经启动。在THERFAT中，对现有的现场经验进行了整理，从而选择了T形连接进行进一步的研究。负载确定包括实验测试和先进的热工水力流动模拟。完整性评价工作包包括应力/疲劳分析和断裂力学评估，并得到目标验证损坏测试的支持。建议将提出改进的负荷热疲劳评估程序，筛选标准，以确定较低的非疲劳显着阈值，并建立一个欧洲的热疲劳方法。[图形]（C）2004 Elsevier B. V.保留所有权利。
Thermal fatigue is a significant long-term degradation mechanism in nuclear power plants (NPP). In particular, as operating plants become older and life time extension activities are initiated. Operators and regulators need screening criteria to exclude risks of thermal fatigue and methods to determine significant fatigue relevance. In general, the common thermal fatigue issues are well understood and controlled by plant instrumentation at fatigue susceptible locations. However, incidents indicate that certain piping system Tee's are susceptible to turbulent temperature mixing effects that cannot be adequately monitored by common thermocouple instrumentations. Therefore, a European project on thermal fatigue evaluation of piping system Tee-connections THERFAT has been initiated. In THERFAT, a collation of existing field experience has been conducted leading to a selection of Tee-connections for further investigations. The load determination covers experimental tests and advanced thermo-hydraulic flow simulations. The integrity evaluation work package comprises stress/fatigue analyses and fracture mechanics assessments supported by targeted verification damage tests. Proposals will be made for improved load thermal fatigue assessment procedures, screening criteria to determine lower non fatigue significant threshold values and for establishing a European methodology on thermal fatigue.[GRAPHICS](C) 2004 Elsevier B.V. All rights reserved.