Hydro-thermal-mechanical analysis of thermal fatigue in a mixing tee
T. Payen, S.Chapuliot, C. Gourdin, J.P. Magnaud, A. Monavon,
Third International Conference on Fatigue of Reactor Components, Seville, Spain, October 3-6, 2004,
Rapport DSR 32
This article describes the approach adopted by the CEA to establish natural mechanisms (turbulence, pulsing and instability) which might be the cause of any substantial thermo-mechanical loading in the piping. This work is supported by IRSN. The main goal of the work is to analyse, by calculation, the thermal loading caused by turbulent mixing in tees and to understand the mechanism of initiation and propagation of cracks in such components.
One of the originalities of this study is to have carried out the overall analysis to the complex 3D geometry of the Civaux unit 1 case (which includes a mixing tee, elbows and straight sections - thermal-hydraulic and thermo-mechanical) with a single computer code, the CAST3M code developed by the CEA.