Cr-doped U3Si2 composite fuels under steam corrosion

Abstract

Dense Cr-doped U3Si2 composite fuels were manufactured by spark plasma sintering, and the effects of Cr addition on mechanical properties and oxidation resistance were investigated. Dynamic oxidation testing by thermogravimetric analysis revealed significantly improved oxidation resistance of U3Si2 with minimal doping of 3 wt% Cr. The onset oxidation temperature increased to above 550 °C in air and ∼520 °C in steam conditions for the 5 wt% and 10 wt% Cr-doped composites. Steam corrosion testing under 360 °C for 24 hours indicated well-maintained pellet integrity without pulverization for the 10 wt% Cr-doped U3Si2 pellet which only showed minor surface oxidation. The first promising results open up the possibility of designing and manufacturing metal additive-doped U3Si2 composite fuels with significantly-improved corrosion resistance as a potential candidate for accident tolerant fuels.