OLANDIR VERCINO CORREA

OLANDIR VERCINO CORREA

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Tribology analysis on anodized aluminum surfaces for biomedical purposes
2023 - PIERETTI, EURICO F.; CORREA, OLANDIR V.; NEVES, MAURICIO D.M. das; ANTUNES, RENATO A.; PILLIS, MARINA F.
Coatings to protect spent aluminium-clad research reactor fuel during extended wet storage
2017 - FERNANDES, S.M.C.; CORREA, O.V.; SOUZA, J.A. de; RAMANATHAN, L.V.; ANTUNES, R.A.; OLIVEIRA, M.C.L. de
Conversion coatings have been used to protect aluminium surfaces from corroding. Hence use of this type of coating was considered to protect the aluminium cladding of spent research reactor fuels during extended wet storage. A conventional chemical process, as opposed to an electrochemical process, is preferred due to the shape of the fuel and its high radioactivity. In this context hydrotalcite (HTC) and boehmite coatings were considered. This paper presents the results of further development of HTC coatings, from the stand point of eventually being able to coat highly radioactive spent fuels using remote handling equipment. More specifically: (a) preparation of HTC coatings from different baths on AA 6061 alloy surfaces that were given pre-treatments to simulate spent fuel surfaces; (b) characteristics of the HTC coatings as a function of bath temperature; (c) corrosion behaviour of HTC coated AA 6061 alloy; (d) results of field studies in which dummy fuel elements, consisting of Al alloy plates coated with HTC from different baths (with or without post coating treatments), were immersed in the IEA-R1 reactor’s spent fuel basin for periods of up to 2 years. This study demonstrates that Al surfaces can be coated with HTC using an allroom temperature process. The field tests revealed marked increase in corrosion resistance of HTC coated plates. The mechanism of corrosion protection is discussed and a mock-up arrangement to remotely handle dummy-fuel elements to pre-treat, coat with HTC and post-treat is presented.
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.
Protective coatings for long term wet storage of spent aluminium-clad research reactor fuel
2014 - FERNANDES, S.M.; CORREA, O.V.; SOUZA, J.A.; RAMANATHAN, L.V.; ANTUNES, R.A.; OLIVEIRA, M.C.L de
Lanthanide based conversion coatings for long term wet storage of aluminium-clad spent fuel
2010 - FERNANDES, S.M.C.; CORREA, O.V.; SOUZA, J.A. de; RAMANATHAN, L.V.
Spent fuels from research reactors are stored in basins with water of less than desirable quality at many facilities around the world and instances of cladding failure caused by pitting corrosion have been reported. Conversion coatings have been used in many industries to protect different metals, including aluminium alloys. This paper presents the results of an ongoing investigation in which the corrosion resistance of lanthanide (cerium, lanthanum and praseodymium) based conversion coated RR fuel cladding alloys has been studied. Electrochemical tests in the laboratory revealed higher corrosion resistance of CeO2, La2O3 and Pr2O3 coated AA 1100 and AA 6061 alloys in NaCl solutions. Uncoated and CeO2 coated coupons of these alloys exposed for 50 days to the spent fuel basin of the IEA-R1 research reactor in IPEN, Brazil, revealed marked reductions in the extent of pitting corrosion.
Effect of preparation technique on the extent of corrosion protection of aa 6061 alloy by hydrotalcite coatings
2014 - FERNANDES, S.M.; CORREA, O.V.; SOUZA, J.A.; RAMANATHAN, L.V.; ANTUNES, R.A.; OLIVEIRA, M.C. de
Conversion coatings to protect spent nuclear fuel during extended wet storage
2012 - FERNANDES, S.M.C.; CORREA, O.V.; SOUZA, J.A. de; RAMANATHAN, L.V.
Coatings for increased corrosion resistance of aluminium-clad spent fuel in wet storage
2012 - FERNANDES, S.M.C.; CORREA, O.V.; SOUZA, J.A. de; RAMANATHAN, L.V.
Hydrotalcite and Boehmite coatings for increased protection of Aluminum clad spent nuclear fuel
2012 - FERNANDES, STELA M.C.; CORREA, OLANDIR V.; SOUZA, JOSE A. de; RAMANATHAN, LALGUDI V.
It is essential to increase the corrosion resistance of Al-clad research reactor (RR) spent fuels during long term wet storage. Laboratory and field tests were carried out to evaluate the pitting corrosion resistance of rare earth containing conversion coatings on Al alloys, AA 1100 and AA 6061, used as cladding of RR fuel plates. These investigations were extended to include boehmite and hydrotalcite (HTC) coatings on Al alloy surfaces. Characterization of the coatings was done with the aid of SEM/FEG/EDS and x-ray diffraction analysis. The electrochemical behavior of uncoated and coated specimens was determined in 0.1 M NaCl. Field tests were carried out in which uncoated, lanthanide-based conversion coated, boehmite coated, cerium modified boehmite coated, HTC coated and cerium modified HTC coated Al alloy coupons were exposed to the IEA-R1 reactor spent fuel basin for varying periods and then their corrosion resistance evaluated. Most of the coatings increased the pitting corrosion resistance of the two alloys and among the coatings, the cerium modified HTC coating was the most efficient.
Protection od spent aluminium-clad research reactor fuels during extended wet storage
2013 - FERNANDES, STELA M.C.; CORREA, OLANDIR V.; SOUZA, JOSE A .; ANTUNES, RENATO A.; OLIVEIRA, MARA C.L. de; RAMANATHAN, LALGUDI V.