Cr coatings to protect zirconium fuel claddings

Crucial accidents at the Three Mile Island and Fukushima nuclear power plants occurred as a result of loss of coolant (LOCA) and bursts of reactivity. It showed a danger of a rapid reaction of steam with zirconium at high temperatures. Nowadays, a lot of science groups are developing accident tolerant nuclear fuel (ATF).
This work is devoted to study of oxidation resistance of zirconium E110 alloy with a protective coating of chromium. For this, several series of E110 samples were prepared using by using magnetron sputtering and investigations of their resistance under normal operation and LOCA scenarios were performed.
It was shown the role of deposition technology on the coating properties (thickness, microstructure, mechanical parameters, adhesion), resistance to oxidation during autoclave tests (360 ° С, 186 atm) and LOCA conditions.
The studies showed that surface modification of zirconium fuel cladding by chromium coating can significantly reduce its oxidation, increase the time until zirconium start to interact with oxygen and improve the safety of light water nuclear power reactors.
The work was supported by the Russian Science Foundation [grant No. 19-79-10116].