Progress in the study of anti-oxidant mechanism and performance enhancement of accident tolerant fuel UN

Uranium nitride (UN) is considered to be one of the most promising accident tolerant fuels due to its high uranium density, high thermal conductivity and high melting point. Although UN has demonstrated great value in nuclear applications in respect to nuclear energy safety, its poor high-temperature oxidation resistance and corrosion performance are urgent issues that need to be addressed as an accident-tolerant fuel (ATF) candidate. In view of the low antioxidant performance of UN-based nuclear fuel under in-reactor service conditions, this paper summarizes the oxidation reaction process of UN in air and water vapor and the methods to enhance the antioxidant performance of UN nuclear fuel, which include the use of highly corrosion-resistant ceramics sintered to form a protective barrier and the addition of suitable metal elements for alloying, etc. In addition, this paper summarizes the current scientific issues that need to be urgently addressed in the research on the enhancement of antioxidant properties of new UN-based fuels.