ELITA FONTENELE URANO DE CARVALHO

ELITA FONTENELE URANO DE CARVALHO

(Fonte: Lattes)

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Graduation at Química Industrial from Universidade Federal do Ceará (1978), master's at Nuclear Engineering from Universidade de São Paulo (1992) and doctorate at Nuclear Engineering from Universidade de São Paulo (2004). Has experience in Nuclear Engineering, focusing on Conversion, Enrichment and Manufacture of Nuclear Fuel, acting on the following subjects: combustivel nuclear, fluoreto, tratamento de efluentes, veneno queimavel and meio ambiente. (Text obtained from the Currículo Lattes on October 8th 2021)

Possui graduação em Química Industrial pela Universidade Federal do Ceará (1978), mestrado em Tecnologia Nuclear pela Universidade de São Paulo (1992) e doutorado em Tecnologia Nuclear pela Universidade de São Paulo (2004). Pesquisador do Instituto de Pesquisas Energéticas e Nucleares da Comissão Nacional de Energia Nuclear. Experiência na área de Engenharia de Materiais e Química com ênfase em Conversão, Enriquecimento, Fabricação de Combustível Nuclear, Tratamento de efluentes radioativos e convencionais e reaproveitamento de resíduos industriais e técnicas de caracterização química de materiais. Membro do Instituto Nacional de Tecnologia- INCT para Reatores Nucleares Inovadores. Autor de capítulo de livro intitulado "Radioisotopes: Applications in Physical Sciences, 2011 ISBN: 9789533075105. Título do capítulo: Research Reactor Fuel Fabrication to Produce Radioisotopes. Professor de pós- graduação da Universidade São Paulo nas áreas de caracterização de materiais e de combustível nuclear. Professor visitante na Escola Politécnica da Universidade de São Paulo - modulo I e II de processamento de combustivel nuclear. Bolsista de Produtividade Desen. Tec. e Extensão Inovadora 2 (Texto extraído do Currículo Lattes em 08 out. 2021)

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Sintering behavior of UO2-Er2O3 mixed fuel
2018 - DURAZZO, MICHELANGELO; FREITAS, ARTUR C.; SANSONE, ALBERTO E.S.; FERREIRA, NILDEMAR A.M.; CARVALHO, ELITA F.U. de; RIELLA, HUMBERTO G.; LEAL NETO, RICARDO M.
The incorporation of burnable neutron absorbers into nuclear fuel pellets is important regarding reactivity compensation, which enables longer fuel cycles. The dry mechanical blending route is the most attractive process to accomplish absorbers incorporation because of its simplicity. By using this route, the present work has investigated the sintering behavior of UO2Er2O3 mixed fuel. A comparison with UO2Gd2O3 sintering behavior was presented. The behavior of UO2Er2O3 fuel sintering was similar to that reported for UO2Gd2O3 fuel, e.g. two-stage sintering with two peaks in the shrinkage rate curves. The effect showed to be less pronounced for Er2O3. This was attributed to the characteristics of the Er2O3 powder particles used as raw-material, whose agglomerates can be more easily broken and thus better homogenized during the blending with UO2 powder. These results confirmed that sinterability depends directly on the quality of the homogenization of the powders, as seen previously. A second phase was experimentally detected in the UO2Er2O3 system, but its impact on the sintering behavior of this mixed fuel has not yet been clarified.
Phase quantification in UAlx-Al dispersion targets for Mo-99 production
2018 - CONTURBIA, G.L.C.R.; DURAZZO, M.; CARVALHO, E.F.U. de; RIELLA, H.G.
Uranium aluminide (UAlx) is a mixture of three distinct intermetallic compounds comprised of UAl2, UAl3 and UAl4, where the “x” is used to denote a mixture of those phases. Usually UAlx is formed during the target fabrication process by means of a solid state reaction between the uranium aluminide and aluminum. Quantitative techniques such as image analysis and X-ray diffraction using the Rietveld method were compared for their applicability in the determination of the UAl2, UAl3 and UAl4 concentrations, both in the UAl2 primary ingot and in the UAlx-Al dispersion. The UAlx composition was quantified in all stages of the target manufacturing. The image analysis method was shown to be useful for UAlx phase quantification in the primary UAl2 ingot, but was not applicable in the case of UAlx-Al dispersions. The X-ray diffraction method allowed the quantification of the existing UAlx phases in both the primary ingot and UAlx-Al dispersions. Possible sources of error are discussed. The method of quantification based on X-ray diffraction was shown to be appropriate to monitor the evolution of UAlx phases during the manufacturing process.
Evolution of fuel plate parameters during deformation in rolling
2017 - DURAZZO, M.; VIEIRA, E.; CARVALHO, E.F.U. de; RIELLA, H.G.
The Nuclear and Energy Research Institute IPEN/CNEN-SP routinely produces the nuclear fuel necessary for operating its research reactor, lEA-R1. This fuel consists of fuel plates containing U3Si2-Al composites as the meat, which are fabricated by rolling. The rolling process currently deployed was developed based on information obtained from literature, which was used as a premise for defining the current manufacturing procedures, according to a methodology with an essentially empirical character. Despite the current rolling process being perfectly stable and highly reproducible, it is not well characterized and is therefore not fully known. The objective of this work is to characterize the rolling process for producing dispersion fuel plates. Results regarding the evolution of the main parameters of technological interest, after each rolling pass, are presented. Some defects that originated along the fuel plate deformation during the rolling process were characterized and discussed. The fabrication procedures for manufacturing the fuel plates are also presented. (C) 2017 Elsevier B.V. All rights reserved.
Effect of Al(OH)3 on the sintering of UO2–Gd2O3 fuel pellets with addition of U3O8 from recycle
2017 - SANTOS, LAURO R. dos; DURAZZO, MICHELANGELO; CARVALHO, ELITA F.U. de; RIELLA, HUMBERTO G.
The incorporation of gadolinium as burnable poison directly into nuclear fuel is important for reactivity compensation, which enables longer fuel cycles. The function of the burnable poison fuel is to control the neutron population in the reactor core during its startup and the beginning of the fuel burning cycle to extend the use of the fuel. The implementation of UO2-Gd2O3 poisoned fuel in Brazil has been proposed according to the future requirements established for the Angra-2 nuclear power plant. The UO2 powder used is produced from the Ammonium Uranyl Carbonate (AUC). The incorporation of Gd2O3 powder directly into the AUC-derived UO2 powder by dry mechanical blending is the most attractive process, because of its simplicity. Nevertheless, processing by this method leads to difficulties while obtaining sintered pellets with the minimum required density. The cause of the low densities is the bad sintering behavior of the UO2-Gd2O3 mixed fuel, which shows a blockage in the sintering process that hinders the densification. This effect has been overcome by microdoping of the fuel with small quantities of aluminum. The process for manufacturing the fuel inevitably generates uranium-rich scraps from various sources. This residue is reincorporated into the production process in the form of U3O8 powder additions. The addition of U3O8 also hinders densification in sintering. This study was carried out to investigate the influence of both aluminum and U3O8 additives on the density of fuel pellets after sintering. As the effects of these additives are counterposed, this work studied the combined effect thereof, seeking to find an applicable composition for the production process. The experimental results demonstrated the effectiveness of aluminum, in the form of Al(OH)3, as an additive to promote increase in the densification of the (U,Gd)O2 pellets during sintering, even with high additions of U3O8 recycled from the manufacturing process.
Investigation of powdering ductile gamma U-10 wt%Mo alloy for dispersion fuels
2014 - LEAL NETO, R.M.; ROCHA, C.J.; URANO de CARVALHO, E.; RIELLA, H.G.; DURAZZO, M.
Phase studies in the UOsub(2)-Gdsub(2)Osub(3) system
2010 - DURAZZO, M.; OLIVEIRA, F.B.V.; CARVALHO, E.F.U. de; RIELLA, H.G.
Remarks on the sintering behaviour of UOsub(2)-Gdsub(2)Osub(3) fuel
2010 - DURAZZO, M.; SALIBA SILVA, A.M.; CARVALHO, E.F.U. de; RIELLA, H.G.
Sintering behavior of UOsub(2)-Gdsub(2)Osub(3) fuel: pore formation mechanism
2013 - DURAZZO, M.; SALIBA SILVA, A.M.; CARVALHO, E.F.U.; RIELLA, H.G.