[1A01-04] Radiolysis, Corrosion 1

[1A01] Direct experimental evidence of the reduction of Cr₂O₃ by Zr at high temperature

*Kejian Wei¹, Lijuan Cui¹, Bo Li¹, Zongda Yang¹, Sho Kano¹, Hiroaki Abe¹ (1. UTokyo)

Keywords:Accident tolerant fuel, Cr coating, Oxidation mechanism

Cr-coated Zr alloys are widely considered as one of the most promising candidates for the accident tolerant fuel (ATF). The key degradation process of the Cr coating is the reduction of Cr₂O₃ by Zr. However, there is still a lack of direct experimental evidence for this redox reaction. To analyze the reaction between the Cr₂O₃ and Zry4 alloy, they were first bonded under high temperature. After bonding, a new Cr-enriching layer adjacent to the Zry4 substrate was observed, which was thought to be the direct experimental evidence of the reduction of Cr₂O₃ by Zr. In accompany with this redox reaction, there are also another two important processes, ZrO₂ transformed into α-Zr (O) and the inter diffusion of Cr/Zr happened. Therefore, the present results indicated that a Cr₂O₃ layer is not a sufficient barrier against the inter diffusion of Cr/Zr.