A model for predicting corrosion damage within crevice under heat transfer condition

This paper presents a model based on chemical thermo-hydraulics to quantitatively predict the corrosion damage within crevices under heat transfer conditions. The model considers damage within crevices under heat transfer conditions as a function of corrosion temperature and concentration of chemicals can be extrapolated using data obtained from autoclave tests under the same material and environmental conditions. The model can be used to determine the corrosion temperature and concentration of aggressive chemicals through calculating the localized chemical thermo-hydraulic conditions in crevices to predict corrosion damage. The effect of porous deposits packed within crevices is considered in the model. This paper studied several different geometrical crevices and Zircaloy cladding failure at spacer grids. A test with Zircaloy cladding in simplified spacer grids in a LiOH solution under subcooled boiling condition is described. The predicted results are found to be in good agreement with the experimental data