ROSATOM Completes New Stages in ATF Development Program
ROSATOM has completed the scheduled milestone in development of Russian accident tolerant fuel. The Research Institute of Atomic Reactors (NIIAR) in Dimitrovgrad, Ulyanovsk Region, has completed the second cycle of irradiation of the experimental fuel assemblies with VVER and PWR fuel rods in the MIR research reactor. Each fuel assembly contains 24 fuel elements with four various combinations of cladding and fuel matrix materials. Fuel pellets were made of traditional uranium dioxide, as well as uranium-molybdenum alloy with increased density and thermal conductivity. Zirconium alloy with a chromium coating and chromium-nickel alloy were either used as the rod cladding material.
After each irradiation cycles, several fuel rods of each fuel assembly were extracted for further post-irradiation studies, and the new non-irradiated samples were installed instead. All the irradiated fuel rods have been remaining hermetic.
Furthermore, the Bochvar Institue (a research facility of TVEL Fuel Company of ROSATOM) has started the project of developing the fabrication technology for uranium disilicide pellets (U3Si2) as another option for the ATF fuel matrix. An experimental U3Si2 ingot has been manufactured for the further producing of powder and pellets.https://www.rosatom.ru/upload/medialibrary/32f/32f00e419b93265fc0b3b1fbe12590f8.jpg