Modeling Corrosion Kinetics of Zirconium Alloys in Loss-of-Coolant Accident (LOCA)

Correctly predicting the mechanical behavior of zirconium fuel cladding during a LOCA transient is critical for nuclear safety analysis as the fuel rod needs to maintain its coolable geometry throughout the LOCALOCA sequence. A physically-based zirconium alloy corrosion model called the Coupled Current Charge Compensation (C4) is developed. The model calculates the coupling of oxygen, electron and hydrogen currents and predicts the oxide, oxygen-stabilized $$ \alpha $$-Zr and prior-$$ \beta $$-Zr layers kinetics as well as the oxygen concentration profiles during a LOCA scenario. The results obtained during isothermal conditions are compared to experimental data for validation. Future developments of the C4 model include an implementation into the nuclear performance code BISON, which currently does not provide a physical description of the oxygen and hydrogen concentration profiles in the cladding. Thanks to the C4 implementation into BISON, structural integrity of the fuel cladding following a LOCA event can be assessed.