The Fukushima accident in 2011 revealed some major flaws in traditional nuclear fuel materials under accidental conditions. Thus, the focus of research has shifted toward “accident tolerant fuel” (ATF). The aim of this approach is to develop fuel material solutions that lead to improved reactor safety. The application of protective coatings on the surface of nuclear fuel cladding has been proposed as a near-term solution within the ATF framework. Many coating materials are being developed and evaluated. In this article, an overview of different zirconium-based alloys currently in use in the nuclear industry is provided, and their performances in normal and accidental conditions are discussed. Coating materials proposed by different institutions and organizations, their performances under different conditions simulating nuclear reactor environments are reviewed. The strengths and weaknesses of these coatings are highlighted, and the challenges addressed by different studies are summarized, providing a basis for future research. Finally, technologies and methods used to synthesize thin-film coatings are outlined.

1. Introduction
2. Zirconium Based Alloys
    2.1 Performance of Zirconium Alloys UnderNormal and Accident Conditions
3. Overview of ATF Cladding Concepts
4. Protective Coatings
    4.1 Current Development Status
    4.2 Influence of Coating Thickness
    4.3 Coatings Performance in NormalOperation & Anticipated OperationalOccurrences Conditions
    4.4 Design Basis Conditions
    4.5 Beyond Design Basis Conditions
    4.6 Challenges
5. Thin Films Technologies
6. Conclusions
REFERENCES

• Rofida Hamad Khlifa(National Research Tomsk Polytechnic University) Corresponding author
• Nicolay N. Nikitenkov(National Research Tomsk Polytechnic University)