Surface-modified zirconium (Zr)-based alloys,
mainly by fabricating protective coatings, are being developed
and evaluated as accident-tolerant fuel (ATF) claddings,
aiming to improve fuel reliability and safety during
normal operations, anticipated operational occurrences,
and accident scenarios in water-cooled reactors. In this
overview, the performance of Zr alloy claddings under
normal and accident conditions is first briefly summarized.
In evaluating previous studies, various coating concepts
are highlighted based on coating materials, focusing
on their performance in autoclave hydrothermal corrosion
tests and high-temperature steam oxidation tests. The
challenges for the utilization of coatings, including materials
selection, deposition technology, and stability under
various situations, are discussed to provide some valuable
guidance to future research activities.