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

Korean Radioactive Waste Society (한국방사성폐기물학회)
권호 표지

Immobilization of Radioactive Rare Earth oxide Waste by Solid Phase Sintering

고상소결에 의한 방사성 희토류산화물의 고화

  • Received : 2009.12.23
  • Accepted : 2010.03.05
  • Published : 2010.03.30
Download PDF
⟨ Previous Next ⟩

Abstract

In the pyroprocessing of spent nuclear fuels, LiCl-KCl waste salt containing radioactive rare earth chlorides are generated. The radioactive rare earth oxides are recovered by co-oxidative precipitation of rare earth elements. The powder phase of rare eath oxide waste must be immobilized to produce a monolithic wasteform suitable for storage and ultimate disposal. The immobilization of these waste developed in this study involves a solid state sintering of the waste with host borosilicate glass and zinc titanate based ceramic matrix(ZIT). And the rare-earth monazite which synthesised by reaction of ammonium di-hydrogen phosphate with the rare earth oxides waste, were immobilzed with the borosilicate glass. It is shown that the developed ZIT ceramic wasteform is highly resistant the leaching process, high density and thermal conductivity.

Pyroprocessing에 의한 사용후핵연료 처리 과정에서 방사성 희토류 염화물이 포함된 폐용융염이 발생된다. 이러한 폐 용융염 내에 존재하는 방사성 희토류 염화물을 산화물로 침전시켜 회수함으로서 용융염을 재생할 수 있다. 최종적으로 발생되는 방사성 희토류 산화물의 저장과 처분에 적합한 monolithic 고화체를 제조하기 위한 연구를 수행하였다. 본 연구에서는 고상 소결에 의해 붕규산 유리에 의한 고화체 제조, 희토류 산화물을 모나자이트로 합성한 후 붕규산 유리에 의한 고화체 제조를 수행하였다. 또한 zinc titanate 세라믹이 주요성분인 고화 매질(ZIT)을 개발하여 고화체를 제조하였으며 각각의 고화체에 대한 침출 및 물리화학적 특성을 비교 평가하였다. 고상 소결에 의해 제조된 ZIT 매질 고화체는 내 침출성이 크며 밀도가 크고 열전도도가 우수한 특성을 나타내었다.

Keywords

References

  1. J. J. Laidler, J. E. Battles, W. E. Miller, J. P. Ackerman, E. L. Carls, "Development of pyroprocessing technology," Prog. Nucl. Energy, 31[1/2], pp. 131-140 (1997). https://doi.org/10.1016/0149-1970(96)00007-8
  2. T. Koyama, T. Hijikata, T. Usami, T. Inoue, S. Kitawaki, T. Shinozaka, M. Fukusima, M. Myochin, "Integrated experiments of eletrometallurgical pyroprocessing using plutonium oxide," J. Nucl. Sci. Technol., 44[3], pp. 383-392 (2007).
  3. Jae-Hyung Yoo, Kwon-Pyo Hong and Han-Soo Lee, "A Concepptual design study for a spent fuel pyroprocessing facility of a demonstration scale J. of the Korean Radioactive Waste Society, 6(3), pp. 233-244, (2008).
  4. Reference spent nuclear fuel for pyroprocessing facility design Dong-Keun Cho, Seok-Kyun Yoon, Heui-Joo Choi, Jongwon Choi and Won-II Ko, J. of the Korean Radioactive Waste Society, 6(3), pp. 225-232, (2008).
  5. Y. J. Cho, H. C. Yang, H. C. Eun, E. H. Kim, I. T. Kim, "Characteristics of oxidation reaction of rareearth chlorides for precipitation in LiCI-KCI molten salt by oxygen sparging," J. Nucl. Sci. Technol., 43[10], pp.1280-1286 (2006). https://doi.org/10.3327/jnst.43.1280
  6. C. Lopez, X. Deschanels, J. M. bart, J. M. Boubals, C. Den Auwer, E. Simoni, Solubility of actinide surrogates in nuclear glasses, J. of Nuc. Materials, 312, pp.76-80 (2003). https://doi.org/10.1016/S0022-3115(02)01549-0
  7. A. E. Ringwood, S. E. Kesson, N. G. Ware, W. D. Hibberson and A. Ma,jor, "The SYNROC process: A geochemical approach to nuclear waste immobilization", Geochem. J., 13[141] (1979)
  8. A. E. Ringwood, S. E. Kesson, N. G. Ware, W. D. Hibberson and A. Major, "Immobilization of high level nuclear reactor waste in SYNROC", Nature, 278(219), (1979)
  9. J. Campbell, C. L. Hoenig, F. Ryerson, M. Guiman, R. V. Konynenburg and R. Rozsa, "Properties of SYNROC-D nuclear wasteform: A-State-the-Art Review", UVRL-53240 (1982)
  10. F. Poitras son, E. Olekers, J. Schott, and J. M. Montel, "Experimental determination of synthetic NdPO4 monazite end-member solubility in water from $21^{\circ}C$ to $300^{\circ}C$: Imbrications of rare earth element mobility in crustal fluids", Geochemica et Cosmochimica Acta, 40[10], pp. 2207-2221 (2004).
  11. L. Bois, M.J.Guittet, F. Carrot, P. Trocellier, M. Gautier-Soyer, " Preliminary results on the leaching process of phosphate ceramics potential hosts for actinide immobilization", J. Nuc. Materials, 297, pp. 129-137 (2001) https://doi.org/10.1016/S0022-3115(01)00607-9
  12. B. Damien, A. Fabienne, C. Thibault, S. Dimitri, and B. A. Didier, "Solid-state synthesis of monazite -type compounds $LnPO_{4}$ (Ln=La to Gd)", Solid State Science, 9, pp.432-439 (2007). https://doi.org/10.1016/j.solidstatesciences.2007.03.019
  13. ASTM C 1285-94, Standard Test Methods for Determining Chemical Durability of Nuclear Waste Glasses: The Product Consistency Test (PCT)," Annual Book of ASTM Standards, American Society for Testing and Materials, West Conshohoken, PA, (1995).