OLANDIR VERCINO CORREA
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Artigo IPEN-doc 23674 Hydrotalcite coatings to protect spent sluminum-clad nuclear fuels during long term wet storage2015 - FERNANDES, S.M.C.; CORREA, O.V.; SOUZA, J.A. de; ANTUNES, R.A.; OLIVEIRA, M.C.L. de; RAMANATHAN, L.V.Pitting corrosion of the aluminium cladding of spent research reactor (RR) fuels in wet storage has been reported and attributed to synergistic influence of certain water parameters. Hence, use of conversion coatings to protect spent Al-clad RR fuel during long term wet storage was proposed. The objective was to develop a coating using a conventional chemical process as opposed to an electrochemical process due to constraints related to the shape of the fuel and its high radioactivity. In this context hydrotalcite (HTC) and boehmite were considered. This paper presents: (a) preparation of boehmite and hydrotalcite (HTC) coatings from different baths followed by post-coating treatments; (b) corrosion behavior of coated AA 6061 alloy; (c) results of field studies in which uncoated and 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 periods of up to 14 months. The laboratory tests revealed marked increase in corrosion resistance of HTC coated specimens. In field tests the HTC coated coupons and plates did not reveal any pits. The mechanism of corrosion protection is presented.Artigo IPEN-doc 22349 Corrosion behavior of hydrotalcite coated AA 6061 alloy2014 - FERNANDES, STELA M.; CORREA, OLANDIR V.; SOUZA, JOSE A.; RAMANATHAN, LALGUDI V.; ANTUNES, RENATO A.; OLIVEIRA, MARA C. dePitting 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.Artigo IPEN-doc 22318 Protective coatings for long term wet storage of spent aluminium-clad research reactor fuel2014 - FERNANDES, S.M.; CORREA, O.V.; SOUZA, J.A.; RAMANATHAN, L.V.; ANTUNES, R.A.; OLIVEIRA, M.C.L deArtigo IPEN-doc 21711 Effect of processing on microstructure and corrosion mitigating properties of hydrotalcite coatings on AA 6061 alloy2015 - FERNANDES, STELA M. de C.; CORREA, OLANDIR V.; SOUZA, JOSE A.B. de; ANTUNES, RENATO A.; LIMA, NELSON B. de; RAMANATHAN, LALGUDI V.Artigo IPEN-doc 21603 Efeito da temperatura de recozimento sobre a resistência à corrosão de revestimentos de Ni-W-P obtidos por deposição química2015 - CORREA, OLANDIR V.; LIMA, NELSON B. de; ETT, BARDIA; OLIVEIRA, MARA C.L. de; ANTUNES, RENATO A.Artigo IPEN-doc 20475 Effect of preparation technique on the extent of corrosion protection of aa 6061 alloy by hydrotalcite coatings2014 - FERNANDES, S.M.; CORREA, O.V.; SOUZA, J.A.; RAMANATHAN, L.V.; ANTUNES, R.A.; OLIVEIRA, M.C. deArtigo IPEN-doc 19256 Protection od spent aluminium-clad research reactor fuels during extended wet storage2013 - FERNANDES, STELA M.C.; CORREA, OLANDIR V.; SOUZA, JOSE A .; ANTUNES, RENATO A.; OLIVEIRA, MARA C.L. de; RAMANATHAN, LALGUDI V.Artigo IPEN-doc 19621 Coatings for increased protection of aluminium clad spent nuclear fuel during long term wet storage2013 - FERNANDES, S.M.C.; CORREA, O.V.; SOUZA, J.A. de; LIMA, N.B. de; RAMANATHAN, L.V.; ANTUNES, R.A.; OLIVEIRA, M.C.L. deArtigo IPEN-doc 19619 Conversion coatings to protect Al-CLAD spent fuel in wet storage2013 - FERNANDES, S.M.C.; CORREA, O.V.; SOUZA, J.A. de; LIMA, N.B. de; RAMANATHAN, L.V.; ANTUNES, R.A.; OLIVEIRA, M.C.L. deArtigo IPEN-doc 18118 Estudo do efeito de tratamentos térmicos de recozimento sobre a resistência à corrosão de eletrodepósitos de Ni-P2011 - ANTUNES, RENATO A.; OLIVEIRA, MARA C.L. de; CORREA, OLANDIR V.; PESSINE, ELISABETE J.