Predicting the wall thinning engendered by erosion-corrosion using CFD methodology

Research highlights: → Resulting in pipe repair, plant shutdown, or even personnel injury, erosion- corrosion is indeed a serious piping degradation mechanism for a nuclear power plant (NPP). → A CFD methodology is proposed to investigate the dependence of wall thinning on the hydrodynamic characteristics within the piping. → Based on the curve describing these relationships of near-wall turbulence kinetic energy and wall thinning, an envelopment model is developed to conservatively predict the amount of local wall thinning around the surface of fitting. - Abstract: Erosion-corrosion (EC) is a serious degradation mechanism of piping, especially for nuclear power plants since it may result in the piping damage, plant shutdown, or personnel injury. The majority of this paper investigates the dependence of wall thinning on the hydrodynamic characteristics using the computational fluid dynamics (CFD) methodology. Four piping systems in a pressurized water reactor (PWR) power plant are selected in this investigation. Based on the plots showing the measured wall thinning with the calculated hydrodynamic parameters, the relationship between them is clearly revealed. Utilizing the characteristics of near-wall turbulence kinetic energy, an envelopment model is proposed herein to conservatively predict the amount of wall thinning distributed on the pipe wall. This estimation model can simply predict the possible distributions of severe EC wear sites and subsequently assist the plant staff to schedule the pipe wall monitoring program in the measured range of pipe wall for the fittings.