Fabrication and Characterization of Reaction-Resistant LaYO3 Material for the Melting Crucible of Metal Fuels

LaYO3 which has phase stability at high temperature is introduced as a promising candidate for reaction-preventing crucible materials with Uranium-Zirconium (U-Zr) melt containing rare-earth elements (RE). RE is composed of rare-earth elements such as Nd, Ce, Pr and La. The LaYO3 material was synthesized by a solid-state reaction method at elevated temperature according to a pseudo-phase diagram of LaYO3 and Y2O3. Green compacts blended with La2O3 and Y2O3 powder were made by the Cold Isostatic Pressing (CIP) method, with La2O3 and Y2O3 powders varying with molar ratios from 1.0 to 1:2. LaYO3 synthetics were fabricated at sintering temperatures ranging from 1450°C to 1600°C. LaYO3 pellets sintered at below 1550°C showed a highly dense orthorhombic phase with a perovskite structure, resulting in an enhancing reaction-resistant effect with RE.

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This work was supported by the National Nuclear R&D program funded by Ministry of Science and ICT (RS-2022-00155198) in the Republic of Korea