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Chemical Equilibrium Modeling for Magnetite-Packed Crevice Chemistry in a Nuclear Steam Generator

  • Bahn, Chi-Bum (Department of Nuclear Engineering, Seoul National University) ;
  • Rhee, In-Hyoung (Department of Chemical Engineering, Soonchunhyang University) ;
  • Hwang, Il-Soon (Department of Nuclear Engineering, Seoul National University) ;
  • Park, Byung-Gi (Department of Nuclear Engineering, Seoul National University)
  • Published : 2005.11.20

Abstract

Modeling of a steam generator crevice in a nuclear power system needs to take into account both thermalhydraulic and chemical phenomena. As a first step towards developing a reliable model, a chemical equilibrium model was developed to predict chemical speciation in a magnetite-packed crevice by adopting the “tableau” method. The model was benchmarked with the available experimental data and the maximum deviation did not exceed two orders of magnitude. The developed model was applied to predict the chemical speciation in a magnetite-packed crevice. It was predicted that caustic environment was developed by the concentration of NaOH and the dissolution of magnetite. The model indicated that the dominant aqueous species of iron in the caustic crevice was $FeO_2\;^-$. The increase of electrochemical corrosion potential observed in the experiment was rationalized by the decrease of dissolved hydrogen concentration due to a boiling process. It was predicted that under the deaerated condition magnetite was oxidized to hematite.

Keywords

References

  1. Millett, P. J. Theoretical and Experimental Investigation of Local Concentration Processes in PWR Steam Generators, Ph. D. Dissertation; The University of Connecticut: CT, U.S.A., 1991
  2. Millett, P. J.; Fenton, J. M. Nucl. Tech. 1994, 108, 256
  3. Engelhardt, G. R.; Macdonald, D. D. Corr. Sci. 1999, 41, 2165 https://doi.org/10.1016/S0010-938X(99)00039-6
  4. Engelhardt, G. R.; Macdonald, D. D.; Millett, P. J. Corr. Sci. 1999, 41, 2191 https://doi.org/10.1016/S0010-938X(99)00040-2
  5. Fauchon, C. L. Development and Testing of an Electrochemical Model for PWR Steam Generators Crevice Environment, Master Thesis; Massachusetts Institute of Technology: Cambridge, U.S.A., 2000
  6. Paine, J. P. N. MULTEQ: Equilibrium of an Electrolytic Solution with Vapor-Liquid Partitioning and Precipitation, Volume 2: The Database (Revision 3), NP-5561-CCML, Volume 2, Revision 3; Electric Power Research Institute: San Hose, U.S.A., 1992
  7. Paine, J. P. N.; Millett, P. J. MULTEQ: Equilibrium of an Electrolytic Solution with Vapor-Liquid Partitioning, Volume 3: Theory Manual, NP-5561-CCML Volume 3; Electric Power Research Institute: San Hose, U.S.A., 1992
  8. Morel, F. M. M.; Hering, J. G. Principles and Applications of Aquatic Chemistry; John Wiley & Sons: New York, U.S.A., 1983; p 11
  9. Kim, C. H. Numerical Methods and Computer Programming (in Korean); Kyohaksa: Seoul, Korea, 1990; p 262
  10. Roine, A. HSC Chemistry$^{\circledR}$ for Windows: Chemical Reaction and Equilibrium Software with Extensive Thermochemical Database, User's Guide, Version 5.0; Outokumpu: PORI, Finland, 2002
  11. Shock, E. L.; Helgeson, H. C. Geochim. Cosmochim. Acta 1988, 52, 2009 https://doi.org/10.1016/0016-7037(88)90181-0
  12. Shock, E. L.; Helgeson, H. C.; Sverjensky, D. A. Geochim. Cosmochim. Acta 1989, 53, 2157 https://doi.org/10.1016/0016-7037(89)90341-4
  13. Shock, E. L.; Oelkers, E. H.; Johnson, J. W.; Sverjensky, D. A.; Helgeson, H. C. J. Chem. Soc. Faraday Trans. 1992, 88, 803 https://doi.org/10.1039/ft9928800803
  14. Shock, E. L.; Sassani, D. C.; Willis, M.; Sverjensky, D. A. Geochim. Cosmochim. Acta 1997, 61, 907 https://doi.org/10.1016/S0016-7037(96)00339-0
  15. Sweeton, F.; Baes, C. J. Chem. Thermodynamics 1970, 2, 479 https://doi.org/10.1016/0021-9614(70)90098-4
  16. Diakonov, I. I.; Schott, J.; Martin, F.; Harrichourry, J.-C.; Escalier, J. Geochim. Cosmochim. Acta 1999, 63, 2247
  17. Beverskog, B.; PUIGDOMENECH, I. Corr. Sci. 1996, 38, 2121 https://doi.org/10.1016/S0010-938X(96)00067-4
  18. Bahn, C. B.; Oh, S. H.; Park, B. G.; Hwang, I. S.; Rhee, I. H.; Kim, U. C.; Na, J. W. Nucl. Eng. Des. 2003, 225, 129 https://doi.org/10.1016/S0029-5493(03)00179-1
  19. Bahn, C. B.; Oh, S. H.; Park, B. G.; Hwang, I. S.; Rhee, I. H.; Kim, U. C.; Na, J. W. Nucl. Eng. Des. 2003, 225, 145 https://doi.org/10.1016/S0029-5493(03)00180-8