Structural and microstructural analysis of the U-GD-O system using X-ray diffraction data

• Autor(a) principal: DARIN, GASPAR
• Data de Publicação: 2018
• Outros Autores: IMAKUMA, KENGO, MARTINEZ, LUIS G., TURRILAS, XABIER M., ICHIKAWA, RODRIGO U., SILVA, ANDRE S.B., DURAZZO, MICHELANGELO, RIELLA, HUMBERTO G., URANO, ELITA, INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE
• Tipo de documento: Artigo de conferência
• Título da fonte: Repositório Institucional do IPEN
• Texto Completo: http://repositorio.ipen.br/handle/123456789/28337
• topic: atomic displacements; burnable poisons; critical size; gadolinium oxides; microstructure; mixtures; phase diagrams; uranium; x-ray diffraction

Gadolinium is one of the best neutron absorber materials and its usage can be considered as a burnable poison for Light Water Reactors (LWR) and as a sacrificial material in Sodium Fast Reactor (SFR). Most of the experiments in the literature focus on nuclear fuel with up to 12 wt% Gd2O3. Recently, the phase diagram and melting point has been investigated for high contents of Gd2O3 in the U-Gd-O system, that means a solid solution of the composition (U1-x, Gdx)O2 for 0<x<100%. In this work, we present the analysis of the U-Gd-O system for high contents of Gd2O3 using X-ray diffraction data. Rietveld analysis was applied to obtain cell parameters, atomic positions and atomic displacement factors and compared with literature avaliable. Also, the quantification of phases was performed for the different contents of Gd2O3 in the system. Finally, mean crystallite sizes were determined and correlated with the weight fraction of the phases.