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 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 14598 Lanthanide based conversion coatings for long term wet storage of aluminium-clad spent fuel2010 - 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.Artigo IPEN-doc 16154 Optimization of rare earth additions to increase high temperature oxidation resistance of chromia and alumina forming alloys2010 - FERNANDES, STELA M.; CORREA, OLANDIR V.; RAMANATHAN, LALGUDI V.Artigo IPEN-doc 16153 Lanthanide based conversion coatings to protect aluminum alloys2010 - FERNANDES, S.M.; CORREA, O.V.; SOUZA, J.A.; RAMANATHAN, L.V.Artigo IPEN-doc 18566 Cerium modified conversion coatings to protect aluminium cladding of spent nuclear fuel during extended wet storage2012 - FERNANDES, STELA M.C.; CORREA, OLANDIR V.; SOUZA, JOSE A. de; RAMANATHAN, LALGUDI V.