A kinetic model of fuel/cladding chemical interaction (FCCI) has been developed. By fitting the model to in-pile experimental data, a wastage correlation has been derived that predicts corrosion depth due to FCCI. The model can explain the temperature dependency of the corrosion depth observed in the in-pile experimental data. The model successfully predicts the high corrosion rate observed in out-of-pile simulation tests that employ fission products in cladding capsules.