Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT) (방사성폐기물학회지)

Korean Radioactive Waste Society (한국방사성폐기물학회)
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Assessment on Recovery of Cesium, Strontium, and Barium From Eutectic LiCl-KCl Salt With Liquid Bismuth System

  • Received : 2020.09.14
  • Accepted : 2020.11.19
  • Published : 2020.12.30
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Abstract

This study provides an assessment on a proposed method for separation of cesium, strontium, and barium using electrochemical reduction at a liquid bismuth cathode in LiCl-KCl eutectic salt, investigated via cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy with energy dispersive X-ray spectrometry (SEM-EDS). CV studies were performed at temperatures of 723-823 K and concentrations of the target species up to 4.0wt%. Redox reactions occurring during potential sweeps were observed. Concentration of BaCl2 in the salt did not seem to influence the diffusivity in the studied concentration range up to 4.0wt%. The presence of strontium in the system affected the redox reaction of lithium; however, there were no distinguishable redox peaks that could be measured. Impedance spectra obtained from EIS methods were used to calculate the exchange current densities of the electroactive active redox couple at the bismuth cathode. Results show the rate-controlling step in deposition to be the mass transport of Cs+ ions from the bulk salt to the cathode surface layer. Results from SEM-EDS suggest that Cs-Bi and Sr-Bi intermetallics from LiCl-KCl salt are not thermodynamically favorable.

Keywords

Acknowledgement

This study was performed using two funding sources: (1) The DOE Office of Nuclear Energy's Nuclear Energy University Programs (NEUP) in collaboration with the Pennsylvania State University (NEUP-15-8126) and (2) The Nuclear Regulatory Commission Graduate Student Fellowship received from VCU.

References

  1. J.P. Ackerman, T.R. Johnson, and J.J. Laidler, "Waste Removal in Pyrochemical Fuel Processing for the Integral Fast Reactor", Proc. of Int, Symp. on Actinides: Processing & Materials, 1994 TMS Annual Meeting, CA, San Francisco (1994).
  2. Michael F. Simpson. Developments of Spent Nuclear Fuel Pyroprocessing Technology at Idaho National Laboratory, Idaho National Laborator Report, INL/EXT-12-25124 (2012).
  3. M. Shaltry, S. Phongikaroon, and M.F. Simpson, "Ion exchange kinetics of fission products between molten salt and zeolite-A", Microporous Mesoporous Mater., 152, 185-189 (2012). https://doi.org/10.1016/j.micromeso.2011.11.035
  4. Y. Cho, G. Park, H. Lee, and I. Kim, "Concentration of Cesium and Strontium Elements Involved in a LiCl Waste Salt by a Melt Crystallization Process", Nucl. Technol., 7(3), 325-334 (2010).
  5. Y.Z. Cho, T.K. Lee, J.H. Choi, H.C. Eun, H.S. Park, and G. Il Park, "Eutectic(LiCl-KCl) waste salt treatment by sequencial separation process", Nucl. Eng. Technol., 45(5), 675-682 (2013). https://doi.org/10.5516/NET.06.2013.022
  6. A.N. Williams, M. Pack, and S. Phongikaroon, "Separation of strontium and cesium from ternary and quaternary lithium chloride-potassium chloride salts via melt crystallization", Nucl. Eng. Technol., 47(7), 867-874 (2015). https://doi.org/10.1016/j.net.2015.08.006
  7. M. Shim, H.G. Choi, J.H. Choi, K.W. Yi, and J.H. Lee, "Separation of Cs and Sr from LiCl-KCl eutectic salt via a zone-refining process for pyroprocessing waste salt minimization", J. Nucl. Mater., 491, 9-17 (2017). https://doi.org/10.1016/j.jnucmat.2017.04.036
  8. J. Serp, P. Lefebvre, R. Malmbeck, J. Rebizant, P. Vallet, and J. P. Glatz, "Separation of plutonium from lanthanum by electrolysis in LiCl-KCl onto molten bismuth electrode", J. Nucl. Mater., 340(2-3), 266-270 (2005). https://doi.org/10.1016/j.jnucmat.2004.12.004
  9. H. Kim, N. Smith, K. Kumar, and T. Lichtenstein, "Electrochemical Separation of Barium into Liquid Bismuth by Controlling Deposition Potentials", Electrochim. Acta., 220, 237-244 (2016). https://doi.org/10.1016/j.electacta.2016.10.083
  10. T. Lichtenstein, T.P. Nigl, N.D. Smith, and H. Kim, "Electrochemical deposition of alkaline-earth elements (Sr and Ba) from LiCl-KCl-SrCl2-BaCl2 solution using a liquid bismuth electrode", Electrochim. Acta., 281, 810-815 (2018). https://doi.org/10.1016/j.electacta.2018.05.097
  11. B.R. Westphal, J.C. Price, D. Vaden, and R.W. Benedict, "Engineering-scale distillation of cadmium for actinide recovery", J. Alloys Compd., 444-445 (2007).
  12. S. Lee and J. Jang, "Distillation behavior of cadmium for U recovery from liquid cadmium cathode in pyroprocessing", J. Radioanal. Nucl. Chem., 314(1), 491-498 (2017). https://doi.org/10.1007/s10967-017-5394-8
  13. M. Kurata, Y. Sakamura, T. Hijikata, and K. Kinoshita, "Distribution behavior of uranium, neptunium, rare-earth elements (Y, La, Ce, Nd, Sm, Eu, Gd) and alkaline-earth metals (Sr, Ba) between molten LiCl-KCI eutectic salt and liquid cadmium or bismuth", J. Nucl. Mater., 227(1-2), 110-121 (1995). https://doi.org/10.1016/0022-3115(95)00146-8
  14. T. Toda, T. Maruyama, K. Moritani, H. Moriyama, and H. Hayashi, "Thermodynamic properties of lanthanides and actinides for reductive extraction of minor actinides", J. Nucl. Sci. Technol., 46(1), 18-25 (2009). https://doi.org/10.3327/jnst.46.18
  15. K. Liu, L.Y. Yuan, Y.L. Liu, X.L. Zhao, H. He, G.A. Ye, Z.F. Chai, and W-Q. Shi, "Electrochemical reactions of the Th4+/Th couple on the tungsten, aluminum and bismuth electrodes in chloride molten salt", Electrochim. Acta., 130, 650-659 (2014). https://doi.org/10.1016/j.electacta.2014.03.085
  16. O. Shirai, K. Uozumi, T. Iwai, and Y. Arai, "Electrode reaction of the U3+/U couple at liquid Cd and Bi electrodes in LiCl-KCl eutectic melts", Anal. Sci., 17, i959-i962 (2001).
  17. Y. Sakamura, O. Shirai, T. Iwai, and Y. Suzuki, "Thermodynamics of Neptunium in LiCl-KCl Eutectic/Liquid Bismuth Systems", J. Electrochem. Soc., 147(2), 642 (2000). https://doi.org/10.1149/1.1393246
  18. O. Shirai, K. Uozumi, T. Iwai, and Y. Arai, "Electrode reaction of the Np3+/Np couple at liquid Cd and Bi electrodes in LiCl-KCl eutectic melts", J. Appl. Electrochem., 34(3), 323-330 (2004). https://doi.org/10.1023/B:JACH.0000015615.17281.51
  19. O. Shirai, M. Iizuka, T. Iwai, and Y. Arai, "Electrode reaction of Pu3+/Pu couple in LiCl-KCl eutectic melts: comparison of the electrode reaction at the surface of liquid Bi with that at a solid Mo electrode.", Anal. Sci., 17(1), 51-57 (2001). https://doi.org/10.2116/analsci.17.51
  20. Y. Castrillejo, M.R. Bermejo, P.D. Arocas, A.M. Martinez, and E. Barrado, "The electrochemical behaviour of the Pr(III)/Pr redox system at Bi and Cd liquid electrodes in molten eutectic LiCl-KCl", J. Electroanal. Chem., 579(2), 343-358 (2005). https://doi.org/10.1016/j.jelechem.2005.03.001
  21. Y. Castrillejo, M.R. Bermejo, P. Diaz Arocas, F. De la Rosa, and E. Barrado, "Electrode reaction of cerium into liquid bismuth in the eutectic LiCl-KCl", Denki Kagaku., 37(3), 636-643 (2005).
  22. Y. Castrillejo, R. Bermejo, A.M. Martinez, E. Barrado, and P. Diaz Arocas, "Application of electrochemical techniques in pyrochemical processes-Electrochemical behaviour of rare earths at W, Cd, Bi and Al electrodes", J. Nucl. Mater., 360(1), 32-42 (2007). https://doi.org/10.1016/j.jnucmat.2006.08.011
  23. M. Li, Q. Gu, W. Han, X. Zhang, Y. Sun, M. Zhang, and Y. Yan, "Electrochemical behavior of La(iii) on liquid Bi electrode in LiCl-KCl melts. Determination of thermodynamic properties of La-Bi and Li-Bi intermetallic compounds", RSC Adv., 5(100), 82471-82480 (2015). https://doi.org/10.1039/C5RA12723H
  24. W. Han, N. Ji, J. Wang, M. Li, X. Yang, Y. Sun, and M. Zhang, "Electrochemical formation and thermodynamic properties of Tb-Bi intermetallic compounds in eutectic LiCl-KCl", RSC Adv., 7(50), 31682-31690 (2017). https://doi.org/10.1039/C7RA04448H
  25. A.V. Volkovich, "Diffusion Coefficients of Alkaline-Earth Metal Ions in Molten Equimolar Mixtures of Potassium and Sodium Chlorides", Melts, 7(106), 43-43 (1993).
  26. M. Matsumiya, R. Takagi, and R. Fujita, "Recovery of EU2+ and Sr2+ using liquid metallic cathodes in molten nacl-kcl and kcl system", J. Nucl. Sci. Technol., 34(3), 310-317 (1997). https://doi.org/10.1080/18811248.1997.9733666
  27. M. Matsumiya, M. Takano, R. Takagi, and R. Fujita, "Recovery saof Ba2+ using liquid metallic cathodes in molten chlorides", J. Nucl. Sci. Technol., 35(11), 836-839 (1998). https://doi.org/10.1080/18811248.1998.9733952
  28. M. Matsumiya, M. Takano, R. Takagi, and R. Fujita, "Electrochemical Behavior of Ba2+ at Liquid Metal Cathodes in Molten Chlorides", Zeitschrift fur Naturforsch., 54(12), 739-746 (1999). https://doi.org/10.1515/zna-1999-1211
  29. M. Matsumiya, H. Matsuura, R. Takagi, and R. Fujita, "Continuous recovery of concentrated solute from the melt by countercurrent electromigration", J. Alloys Compd., 306(1-2), 87-95, (2000). https://doi.org/10.1016/S0925-8388(99)00813-0
  30. M. Matsumiya and R. Takagi, "Electrochemical impedance spectroscopic study on Eu2+ and Sr2+ using liquid metal cathodes in molten chlorides", Zeitschrift fur Naturforsch. - Sect. A J. Phys. Sci., 55(8), 673-681 (2000). https://doi.org/10.1515/zna-2000-0802
  31. T. Lichtenstein, N.D. Smith, J. Gesualdi, K. Kumar, and H. Kim, "Thermodynamic properties of Barium-Bismuth alloys determined by emf measurements", Electrochim. Acta, 228, 628-635 (2017). https://doi.org/10.1016/j.electacta.2016.12.141
  32. J.M.P.Q. Delgado and M. Vazquez da Silva, "Analytical Solutions of Mass Transfer around a Prolate or an Oblate Spheroid Immersed in a Packed Bed", in Multiphase System and its Applications, Mohamed El-Amin, ed, 765-780, InTech, London (2011).
  33. D. Yoon, S. Phongikaroon, and J. Zhang, "Electrochemical and Thermodynamic Properties of CeCl3 on Liquid Cadmium Cathode (LCC) in LiCl-KCl Eutectic Salt", J. Electrochem. Soc., 163(3), E97-E103 (2016). https://doi.org/10.1149/2.0101605jes
  34. D. Yoon, "Electrochemical Studies of Cerium and Uranium in LiCl-KCl Eutectic for Fundamentals of Pyroprocessing Technology", Virginia Commonwealth University, Accessed Dec. 14 2016. Available from: https://scholarscompass.vcu.edu/cgi/viewcontent.cgi?article=5690&context=etd.
  35. A. Lasia, Electrochemical Impedance Spectroscopy and Its Applications, 1st ed., 143-248, Springer, New York (2014).
  36. D. Yoon and S. Phongikaroon, "Measurement and Analysis of Exchange Current Density for U/U3+ Reaction in LiCl-KCl Eutectic Salt via Various Electrochemical Techniques", Electrochim. Acta, 227, 170-179 (2017). https://doi.org/10.1016/j.electacta.2017.01.011