High Cycle Thermal Fatigue in French PWR
High Cycle Thermal Fatigue in French PWR
复制标题
DOI：
10.1115/icone10-22762
复制
发表时间：
2002
期刊：
影响因子：
--
通讯作者：
E. Blondet;C. Faidy
中科院分区：
文献类型：
--
作者：
E. Blondet;C. Faidy
世界上反应堆冷却剂系统（SIS、RHR、CVC）辅助管线上发生的不同疲劳相关事故促使EDF寻找解决方案，以避免或限制热力学现象（Farley-Tihange、自由对流回路和分层、独立热循环）的后果。研究是在模拟上进行的，并与核电站上的仪表进行比较。目前，研究使EDF能够进行管道改造，并为下一代核电厂制定规范和建议。1998年，在Civaux的RHR系统上出现了一个新现象。在冷热流体（温差140度）的区域发现了裂缝。C）混合。冶金学研究得出结论，这种裂纹是由高循环热疲劳引起的。自1998年以来，EDF正在根据标准对法国压水堆的所有混合区进行清点。对于所有识别的区域，开发了一种方法来改进第一分类，并仅保留潜在的损坏管道。目前，正在对连接到反应堆压力容器的装料管线喷嘴进行研究。为了评估载荷历史，已经开发了一个实体模型，并在该喷嘴上实现了机械计算。本文将对EDF在以下不同点上的结论进行概述：-无流动连接管线中的盲管段和涡流; -分层; -具有高{delta}T的混合三通。（作者）«少
Different fatigue-related incidents which occurred in the world on the auxiliary lines of the reactor coolant system (SIS, RHR, CVC) have led EDF to search solutions in order to avoid or to limit consequences of thermodynamic phenomenal (Farley-Tihange, free convection loop and stratification, independent thermal cycling). Studies are performed on mock-up and compared with instrumentation on nuclear power stations. At the present time, studies allow EDF to carry out pipe modifications and to prepare specifications and recommendations for next generation of nuclear power plants. In 1998, a new phenomenal appeared on RHR system in Civaux. A crack was discovered in an area where hot and cold fluids (temperature difference of 140 deg. C) were mixed. Metallurgic studies concluded that this crack was caused by high cycle thermal fatigue. Since 1998, EDF is making an inventory of all mixing areas in French PWR on basis of criteria. For all identified areas, a method was developed to improve the first classifying and to keep back only potential damage pipes. Presently, studies are performing on the charging line nozzle connected to the reactor pressure vessel. In order to evaluate the load history, a mock-up has been developed and mechanical calculations are realised onmore » this nozzle. The paper will make an overview of EDF conclusions on these different points: - dead legs and vortex in a no flow connected line; - stratification; - mixing tees with high {delta}T. (authors)« less