Corrosion behavior of Fe-based candidate accident tolerant fuel cladding alloys in spent fuel pool environment - Effect of prior corrosion

The corrosion behavior of Fe-based candidate accident tolerant fuel (ATF) cladding alloys, such as FeCrAl and FeNiCrAl alloys, in simulated spent fuel pool (SFP) water was investigated. Specimens with different prior corrosion histories, such as fresh, normal-serviced (immersed in simulated pressurized water reactor (PWR) environment), and accident-suffered (PWR water immersion followed by high-temperature steam exposure) were used. All Fe-based alloys with various prior corrosion histories show weight loss during the SFP immersion test. In the fresh and normal-serviced conditions, all alloys experience relatively small weight loss in SFP water. In the accident-suffered condition, low-Al FeNiCrAl alloy shows large weight loss. Overall, high-Al FeNiCrAl alloy shows comparable corrosion resistance to FeCrAl alloy in SFP water for all prior corrosion histories. The corrosion behavior of the alloys in SFP water is significantly affected by the pre-formed oxides, such that Cr2O3, Al2O3, Fe-rich and Cr-rich spinel oxides offer better corrosion resistance than Fe2O3. (C) 2021 Elsevier B.V. All rights reserved.