JOSE ANTONIO BATISTA DE SOUZA

JOSE ANTONIO BATISTA DE SOUZA

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Coatings for safe long term wet storage of spent Al-clad research reactor fuels
2015 - RAMANATHAN, L.V.; FERNANDES, S.M.C.; CORREA, O.V.; SOUZA, J.A. de; ANTUNES, R.A.; OLIVEIRA, M.C.L. de
Pitting corrosion of the aluminium cladding of spent research reactor (RR) fuels in wet storage has been observed and the use of conversion coatings to protect the cladding was proposed. A coating prepared by conventional chemical processing as opposed to electrochemical processing is the only option due to constraints related to the shape of the fuel and its high radioactivity. Hence, hydrotalcite (HTC) and boehmite were considered. This paper presents: (a) preparation of hydrotalcite (HTC) coatings from different baths followed by post-coating treatments; (b) corrosion behavior of HTC coated AA 6061 alloy; (c) results of field studies in which uncoated and HTC coated AA 6061 alloy coupons and plates, the latter assembled as a dummy fuel element, were exposed to the IEA-R1 reactor spent fuel basin for extended periods. The laboratory and field tests revealed marked improvements in the corrosion resistance of HTC coated specimens, coupons and plates. The mechanism of corrosion protection is presented.
Development of irradiation targets for 99Mo production by nuclear fission
2016 - DURAZZO, M.; CONTUBIA, G.; SOUZA, J.A.B.; CARVALHO, E.F.U. de; RIELLA, H.G.
Preparation and characterization of hydrotalcite coatings to protect aluminium alloys
2016 - FERNANDES, S.M.C.; CORREA, O.V.; SOUZA, J.A.; ANTUNES, R.A.; LIMA, N.B. de; RAMANATHAN, L.V.
Pitting corrosion of the aluminium alloy cladding of spent research reactor fuels during wet storage is the main form of degradation. To prevent this, hydrotalcite (HTC) based coatings were proposed. This paper presents the effect of chemical bath parameters on the microstructure of HTC coatings and the corrosion behavior of HTC coated AA 6061 specimens. The HTC coating formed at 98 °C from nitrate baths and referred to as HT-HTC was homogeneous and consisted of intersecting blade-like crystallites. Electrochemical tests revealed that HT-HTC coated specimens that were treated in a cerium salt solution were the most resistant to corrosion. Field tests in which un-coated and HTC coated AA 6061 alloy coupons as well as full-size plates were exposed to the IEA-R1 reactor’s spent fuel basin for 23 months corroborated the high corrosion resistance imparted by the HT-HTC + Ce coating. The mechanism by which the HTC coating and cerium protect the Al alloy is discussed.
Susceptibility of M5sup(TM) (ZrNbO) alloy to pitting corrosion at different temperatures
2014 - CORREA, OLANDIR V.; OLIVEIRA, MARA C.L. de; PESSINE, ELISABETE J.; SOUZA, JOSE A.B. de; ANTUNES, RENATO A.
Corrosion of fuel cladding is a major concern in the nuclear industry. Zirconium alloys are the standard materials for nuclear fuel tubing due to its notable low neutron absorption crosssection. The M5sup(TM) alloy is currently employed for the production of nuclear fuel cladding in Brazil. Pitting corrosion has been associated with the intergranular stress corrosion cracking of these materials. In this regard, the study of pitting corrosion behavior of M5sup(TM) alloy is of great technological interest in order to allow the development of safer nuclear fuel claddings. The aim of this work was to evaluate the pitting corrosion behavior of M5sup(TM) alloy at different temperatures. Electrochemical measurements comprised potentiodynamic polarization and electrochemical impedance spectroscopy analyses. The tests were conducted in 5.0 wt.% NaCl solution at room temperature, 40 ºC and 60 ºC. The corrosion resistance was shown to be dependent on the testing temperature. The M5sup(TM) alloy showed good corrosion resistance with only a slight decay as the temperature increased.
Corrosion behavior of hydrotalcite coated AA 6061 alloy
2014 - FERNANDES, STELA M.; CORREA, OLANDIR V.; SOUZA, JOSE A.; RAMANATHAN, LALGUDI V.; ANTUNES, RENATO A.; OLIVEIRA, MARA C. de
Pitting corrosion of the aluminium cladding of spent research reactor (RR) fuel during wet storage is the main form of degradation and this could eventually lead to release of fissile material and contamination of storage facilities. Hence, the use of conversion coatings to protect spent Al-clad RR fuel during long term storage was proposed. Preliminary laboratory and field investigations carried out at IPEN in São Paulo, Brazil, revealed that cerium hydroxide coatings increased the corrosion resistance of Al alloys. These investigations were extended to include boehmite, hydrotalcite (HTC), cerium modified boehmite and cerium modified HTC coatings on Al alloy surfaces. This paper presents: (a) the preparation of hydrotalcite coatings from different baths followed by post-coating treatments; (b) the results of x-ray diffraction analysis and scanning electron microscopic studies of the HTC coatings; (c) the effect of HTC coating process variables such as temperature, duration of treatment and the duration of cerium modification on HTC morphology and electrochemical polarization behavior of HTC coated AA 6061 alloy in NaCl; (d) results of field tests in which uncoated and HTC coated AA 6061 coupons were exposed to the IEA-R1 reactor spent fuel basin for up to 5 months. The laboratory test specimens as well as the field test coupons coated with HTC from a high temperature bath followed by cerium modification were the most resistant to pitting.
Influence of aging time on the corrosion behavior of 6061 Al alloy in alkaline solution
2014 - CORREA, OLANDIR V.; SOUZA, JOSE A.B. de; OLIVEIRA, MARA C.L. de; ANTUNES, RENATO A.
Al alloys of the 6XXX series (Al-Mg-Si) are employed as structural materials in a variety of industrial applications due to a combination of high mechanical strength and good corrosion resistance. The final mechanical properties are achieved after specific precipitation hardening heat treatments. The aging time during precipitation hardening is known to affect these properties and can also influence the corrosion resistance of the alloy. The susceptibility of Al alloys to corrosion in alkaline media is well-known. In this work the effect of aging time on the corrosion behavior of 6061 Al alloy was evaluated in NaOH and NaCl solutions. The material was aged at 200 ºC for times ranging from 1 to 36 h. The corrosion behavior of the aged alloy was studied using potentiodynamic polarization and electrochemical impedance spectroscopy. The results showed that the corrosion resistance was progressively lower for increasing aging times up to 8 h in NaCl and up to 24 h in NaOH. Longer aging times led to a decrease of the corrosion current density.
A CFD numerical model for the flow distribution in a MTR fuel element
2015 - ANDRADE, DELVONEI A. de; ANGELO, GABRIEL; ANGELO, EDVALDO; SANTOS, PEDRO H. di G.; OLIVEIRA, FABIO B.V. de; TORRES, WALMIR M.; EMBEHAUN, PEDRO E.; SOUZA, JOSE A.B. de; BELCHIOR JUNIOR, ANTONIO; SABUNDJIAN, GAIANE; PRADO, ADELK de C.
Current status of Usub(3)Sisub(2) fuel elment fabrication in Brazil
2007 - DURAZZO, M.; CARVALHO, E.F.U. de; SALIBA SILVA, A.M.; SOUZA, J.A.B.; RIELLA, H.G.
Procedimentos de fabricacao de elementos combustiveis a base de dispersoes com alta concentracao de uranio
2010 - SOUZA, J.A.B. de; DURAZZO, M.
Estudo de métodos para caracterização de fases no intermetálico UAlx
2012 - CONTUBIA, G.; GARCIA, R.H.L.; SOUZA, J.A.B. de; CARVALHO, E.F.U. de; RIELLA, H.G.; DURAZZO, M.