Presentation of a Numerical 3D Approach to Tackle Thermal Striping in a PWR Nuclear T-Junction

Abstract

This paper presents a numerical study to tackle thermal striping phenomena occuring in piping systems. It is here applied to the Residual Heat Removal (RHR) bypass system. A large Eddy Simulation (L.E.S.) approach is used to model the turbulent flow in a T-junction. The thermal coupling between the Finite Volume CFD Code_Saturne and the Finite Element thermal code Syrthes, gives access to the instantaneous field inside the fluid and the solid. By using the instantaneous solid thermal fields, mechanical computations (as presented in (Stephan et al 2002)) are performed to yield the instantaneous mechanical stresses seen by the pipework T-junction and elbow.

Approach to a Method of Integrated Evaluation of Thermal Fatigue and its Validation Using SPECTRA

“…The Japan Atomic Energy Agency (JAEA) is currently developing an evaluation method (2) that combines computational fluid dynamics (CFD) with thermal conductive and stress analysis., Électricité de France (EDF) (3) and the French Atomic Energy Commission (CEA) (4) both developed original evaluation methods for thermal fatigue, to investigate the root cause of leakage in the residual heat removal system of Civaux Unit No.1 in 1998. These organizations employ originally developed codes for CFD, thermal conductive, and stress analysis.…”