MODIFICATION OF THE SURFACE AND COATING APPLICATION ON FUEL CLADDING TUBES FOR nuclear reactors
We present a review of the methods for increasing the corrosion resistance of fuel rods of thermal and fast nuclear reactors using surface modification and coating application to improve the safety and efficiency of operation of nuclear fuel. We report the results of tests carried out at the SSC RF TRINITI with coatings on fuel claddings made of EP-823 steel, considered for use in the BREST-OD-300 reactor, and of zirconium alloy E110, i.e. the “forward” of Russian commercial nuclear power energy. Corrosion tests of experimental samples of fuel claddings with Al, Al2O3, Cr coatings in liquid lead with a high oxygen content and a temperature of 650-720 °C (for steel shells) and on air at a temperature of 1100 °C (for zirconium shells) showed almost complete corrosion suppression. Physical barriers to the applicability of coatings as protective layers on fuel claddings are identified: fretting corrosion of fuel element shells, the problem of low heat resistance of fuel element shells, the problem of high residual energy release of fuel elements, the lack of self-healing of protective ceramic coatings, and the problem of low-temperature radiation embrittlement of coatings. We have proposed solutions to the problems of protecting nuclear power plants.