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

Korean Radioactive Waste Society (한국방사성폐기물학회)
권호 표지
DOI QR코드

DOI QR Code

Loss of Li2O Caused by ZrO2 During the Electrochemical Reduction of ZrO2 in Li2O-LiCl Molten Salt

Li2O-LiCl 용융염을 이용한 ZrO2의 전기화학적 환원과정에서 발생하는 Li2O의 손실

  • Received : 2012.07.19
  • Accepted : 2012.10.23
  • Published : 2012.12.30
Download PDF
⟨ Previous Next ⟩

Abstract

A molten salt technology using $Li_2O$-LiCl has been extensively investigated to recover uranium metal from spent fuels in the field of nuclear energy. In the reduction process, it is an important point to maintain the concentration of $Li_2O$. $ZrO_2$ is inevitably contained in the spent fuels because Zr is one of the main components of fuel rod hulls. Therefore, the fate of $ZrO_2$ in $Li_2O$-LiCl molten salt has been investigated. It was found that $Li_2ZrO_3$ and $Li_4ZrO_4$ were formed chemically and electrochemically and they were not reduced to Zr. The recycling of $Li_2O$ is the key mechanism ruling the total reaction in the electrolytic reduction process. However, $ZrO_2$ will have a role as a $Li_2O$ sink.

$Li_2O$-LiCl 용융염을 이용한 전해환원기술은 사용후핵연료로부터 우라늄 금속을 회수하기 위해 연구되고 있다. 이 전해환원기술에서는 $Li_2O$가 촉매로 이용되기 때문에 그 농도를 유지하는 것은 매우 중요한 운전인자이다. $ZrO_2$는 피복관의 주성분이 Zr이기 때문에 사용후핵연료에 불가피하게 함유되며, 본 연구에서는 $Li_2O$를 촉매로 이용하는 전해환원공정에서 $ZrO_2$의 거동을 살펴보았다. $Li_2O$와 $ZrO_2$의 화학반응과 전해환원공정 중에서의 생성물을 분석한 결과, $Li_2ZrO_3$와 $Li_4ZrO_4$가 주요하게 관찰되었고, 이는 $Li_2O$의 손실을 가져오는 원인이 된다. 즉, $ZrO_2$는 $Li_2O$를 소모하는 역할을 하며, 반응생성물은 전기화학적으로 안정하기 때문에 $Li_2O$의 손실이 불가피하게 된다.

Keywords

References

  1. E. J. Karell, K. V. Gourishankar, J. L. Smith, L. S. Chow, L. Redev, "Separation of Actinides from LWR Spent Fuel Using Molten-Salt-Based Electrochemical Process", Nucl. Technol., 136(3), pp. 342-353 (2001).
  2. J. M. Hur, C. S. Seo, S. S. Hong, D. S. Kang, S. W. Park, "Metallization of U3O8 via Catalytic Electrochemical Reduction with Li2O in LiCl Molten Salt", React. Kinet. Catal. Lett., 80(2), pp. 217-222 (2003). https://doi.org/10.1023/B:REAC.0000006128.15961.1d
  3. S. M. Jeong, H. S. Shin, S. H. Cho, J. M. Hur, H. S. Lee, "Electrochemical Behavior of a Platinum Anode for Reduction of Uranium Oxide in a LiCl Molten Salt", Electrochim. Acta, 54, pp. 6335-6340 (2009). https://doi.org/10.1016/j.electacta.2009.05.080
  4. S. D. Herrmann, S. X. Li, "Separation and Recovery of Uranium Metal from Spent Light Water Reactor Fuel via Electrolytiv Reduction and Electrorefining", Nucl. Technol., 171(3), pp. 247-265 (2010).
  5. S. M. Jeong, B. H. Park, J. M. Hur, C. S. Seo, H. S. Lee, K. C. Song, "An Experimental Study on an Electrochemical Reduction of an Oxide Mixture in the Advanced Spent-Fuel Conditioning Process", Nucl. Eng. Technol. 42(2), pp. 183-192 (2010). https://doi.org/10.5516/NET.2010.42.2.183
  6. Y. Sakamura, M. Kurata, T. Inoue, "Electrochemical Reduction of $UO_{2}$ in Molten $CaCl_{2}$ or LiCl", J. Electrochem. Soc., 153(3), pp. D31-39 (2006). https://doi.org/10.1149/1.2160430
  7. J. M. Hur, S. M. Jeong, H. S. Lee, "Underpotential Deposition of Li In a Molten LiCl-$Li_{2}O$ Electrolyte for the Electrochemical Reduction of U from Uranium Oxides", Electrochem. Comm., 12, pp. 706- 709 (2010). https://doi.org/10.1016/j.elecom.2010.03.012
  8. B. H. Park, J. M. Hur, "Behavior of Diffusing Elecmets from an Integrated Cathode of an Electrochemical Reduction Process", Korean J. Chem. Eng., 27(4), pp. 1278-1283 (2010). https://doi.org/10.1007/s11814-010-0191-x
  9. B. H. Park, J. M. Hur, H. S. Lee, "A Chemical Reaction Calculation and a Semi-Emperical Model for the Dynamic Simulation of an Eletrolytic Reduction of Spent Oxide Fuels", J. Kor. Rad. Waste Soc., 8(1), pp. 19-32 (2010).
  10. G. K. Moiseev, N. A. Vatolin, "Interaction of Lithium Zirconate with Lithium under Equilibrium Conditions", Phys. Chem., 388(4), pp. 505-509 (2003).
  11. E. Y. Choi, J. M. Hur, I. K. Choi, S. G. Kwon, D. S. Kang, S. S. Hong, H. S. Shin, M. A. Yoo, S. M. Jeong, "Electrochemical reduction of porous 17 kg uranium oxide pellets by selection of an optimal cathode/anode surface area ratio", J. Nucl. Mater., 418, pp. 87-92 (2011). https://doi.org/10.1016/j.jnucmat.2011.08.001
  12. A. M. Abdelkader, A. Daher, R. A. Abdelkareem, E. El-Kashif, "Preperation of Zirconium Metal by the Electrochemical Reduction of Zirconium Oxide", Metall. Mater. Trans. B., 38B, pp. 35-44 (2007).
  13. K. S. Mohandas, D. J. Fray, "Electrochemical Deoxidation of Solid Zirconium Dioxide in Molten Calcium Chloride", Metall. Mater. Trans. B., 40B, pp. 685-699 (2009).

Cited by

  1. Salt System vol.165, pp.2, 2018, https://doi.org/10.1149/2.0281802jes
  2. Reduction of ZrO2 during SNF Pyrochemical Reprocessing vol.168, pp.3, 2012, https://doi.org/10.1149/1945-7111/abe8be