Understanding the influence of the composition and microstrucutre of Cr based PVD coatings on the performance of coated claddings

Ensuring the safety of nuclear power reactors has been at the forefront of their development, deployment and operation whereby improvements in both materials and fuels technology remains central to the success of the sector.

The main aim of accident tolerant fuel (ATF) development is to identify and evaluate alternative fuel system technologies that can further enhance the safety of light water reactor (LWR) systems.

Enhanced ATFs can tolerate a severe accident in the reactor core for a considerably longer time than the current UO2 - zirconium alloy fuel system, while improving the fuel performance during normal operations and operational transients.

Presently, the addition of a chromium-based coating to Zr through physical vapour deposition (PVD) has been shown to be a promising ATF contender.

However, significant variations in the coating's performance occurs as the deposition parameters and coating design are altered.

Further investigation of the influence of these parameters on the microstructure, mechanical properties and irradiation performance of chromium-based coated claddings is needed if they are to be accepted as a feasible ATF alternative.