OLANDIR VERCINO CORREA

OLANDIR VERCINO CORREA

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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.
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.
Hydrotalcite coatings to protect spent sluminum-clad nuclear fuels during long term wet storage
2015 - 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.
Effect of processing on microstructure and corrosion mitigating properties of hydrotalcite coatings on AA 6061 alloy
2015 - FERNANDES, STELA M. de C.; CORREA, OLANDIR V.; SOUZA, JOSE A.B. de; ANTUNES, RENATO A.; LIMA, NELSON B. de; RAMANATHAN, LALGUDI V.
Effect of mixed rare earth oxide gel coatings on the high temperature oxidation behavior of iron-chromium alloys
2012 - FERNANDES, STELA M.; CORREA, OLANDIR V.; RAMANATHAN, LALGUDI V.
Oxidos de terras raras nanocristalinos para uso como recobrimento protetor das ligas Fe-20Cr expostas a temperaturas elevadas
2013 - FERNANDES, STELA M.C.; CORREA, OLANDIR V.; RAMANATHAN, LALGUDI V.
Lanthanide based conversion coatings to protect aluminum alloys
2010 - FERNANDES, S.M.; CORREA, O.V.; SOUZA, J.A.; RAMANATHAN, L.V.
Cerium modified conversion coatings to protect aluminium cladding of spent nuclear fuel during extended wet storage
2012 - FERNANDES, STELA M.C.; CORREA, OLANDIR V.; SOUZA, JOSE A. de; RAMANATHAN, LALGUDI 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.