Compatibility of fuel-element cladding materials with gallium-containing uranium and uranium–plutonium oxide fuel

Powders of uranium oxide powder and mixed fuel containing 5 and 20 mass % plutonium and 0.4 and 5 mass % gallium were prepared by coprecipitation from nitrate solutions. Pelleted samples for testing were made by cold pressing and sintering. The compatibility of uranium oxide fuel and mixed uranium–plutonium fuel, containing 0.4 and 5 mass % gallium, with the zirconium alloy E-110 at 400 and 500°C and ChS-68 corrosion-resistant steel at 650 and 750°C over periods of 1000, 2000, and 3000 h was investigated. Metallographic and x-ray spectral microprobe analyses of diffusion samples established that there was no interaction and penetration of gallium into the zirconium alloy and steel. In addition, the diffusion coefficient of metallic gallium in zirconium alloy and the distribution of the elements on interaction of gallium with ChS-68 steel were evaluated.