Prediction of tube wear due to flow-induced vibration in PWR steam generators

摘要

Tube wear due to flow-induced vibration has been of continuing concern in operating Pressurized Water Reactor steam generators. Tube plugging or repair is necessary when inservice inspection indicates tube wall thickness less than a minimumacceptable value. Additional considerations involve the use of tube stabilizers or motion limiters when a plugged vibrating tube can impact on its neighboring active tubes. An analytical wear assessment methodology that predicts tube wear caused byflow-induced vibration is described. The methodology is based on determining a set of wear parameters from a non-linear finite element simulation of the steam generator tubes incorporating clearances at the tube supports under flow-induced turbulence andfluidelastic excitation. Tube wear progression during steam generator life is projected from the analytically determined parameters and experimental wear correlations. The methodology is applied to predict tube wear at scheduled inspections in a steamgenerator.