document: Zirconium alloys are commonly used as the fuel cladding for water cooled nuclear fission reactors, mainly due to their low neutron cross-section, good corrosion resistance during normal operating conditions and sufficient mechanical strength [1]. Despite high corrosion resistance at normal operating temperatures (around 300 °C) [2], Zr alloys oxidise very rapidly when exposed to temperatures a few hundred degrees higher. This is an exothermic reaction, which can further accelerate oxidation and, at temperatures beyond 1000 °C, potentially lead to disintegration of the fuel rods, as highlighted during the Fukushima Daiichi nuclear accident. For this reason new research activities have been initiated worldwide to develop accident tolerant fuels (ATF). Additionally, ATFs could also provide further enhancements in corrosion performance during normal operating conditions enabling the development of fuel assemblies for very high burn-up.
extractive_keyphrases: accident tolerant fuels atf development of fuel assemblies disintegration of the fuel rods enhancements in corrosion performance exothermic reaction fuel cladding oxidation oxidise water cooled nuclear fission reactors zirconium alloys zr alloys
abstractive_keyphrases: develop accident tolerant fuels fuel assemblies fuel rods