Investigation on Oxidation Behaviors of FeCrAl Alloy Cladding Under the Simulated LOCA Conditions

Abstract During a LOCA (Loss of Coolant Accident), the zirconium alloy cladding undergoes oxidation, generating significant heat and hydrogen gas. In extreme circumstances, this can result in hydrogen explosions compromising reactor safety. Recently, the ATF (Accident Tolerant Fuel) cladding has been introduced as a new generation of fuel cladding. Among the ATF claddings, FeCrAl alloy cladding exhibits a low oxidation rate during LOCA due to the formation of a dense alumina layer during high-temperature oxidation. However, current research on this FeCrAl alloy cladding remains limited in scope and depth. The present study focuses on the oxidation behavior of FeCrAl alloy cladding at 1200 °C in steam. Key findings include: (1) Spots on the sample were identified as oxides of Fe, Cr, and Al through microscopic analysis. (2) An oxide layer of Al was observed with a thickness ranging from 0.86 μm to 1.98 μm. (3) The ring compression test revealed that the FeCrAl alloy cladding neither fractured nor underwent a ductile-brittle transition.