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

Korean Radioactive Waste Society (한국방사성폐기물학회)
권호 표지
DOI QR코드

DOI QR Code

Removal of Uranium by an Alkalization and an Acidification from the Thermal Decomposed Solid Waste of Uranium-bearing Sludge

알카리화 및 산성화에 의한 우라늄 함유 슬러지의 열분해 고체 폐기물로부터 우라늄 제거

  • Received : 2013.01.29
  • Accepted : 2013.03.20
  • Published : 2013.06.30
Download PDF
⟨ Previous Next ⟩

Abstract

This study has been carried out to elucidate the characteristics of the dissolution for Thermal Decomposed Solid Waste of uranium-bearing sludge (TDSW), the removal of impurities by an alkalization in a nitric acid dissolving solution of TDSW, and the selective removal (/recovery) of uranium by an acidification in an carbonate alkali solution, respectively. TDSW generated by thermal decomposition of U-bearing sludge which was produced in the uranium conversion plant operation, was stored in KAERI as a solid-powder type. It is found that the dissolution of TDSW is more effective in nitric acid dissolution than oxidative-dissolution with carbonate. At 1 M nitric acid solution, TDSW was undissolved about 30wt% as a solid residue, and uranium contained in TDSW was dissolved more than 99%. In order to the alkalization for the nitric acid dissolving solution of TDSW, carbonate alkalization is more effective with respect to remove the impurities. At the carbonate alkali solution controlled to about 9 of pH, Al, Ca, Fe and Zn co-dissolved with U in dissolution step was removed about $98{\pm}1%$. On the other hand, U could be recovered more than 99% by an acidification at pH about 3 in a carbonate alkali solution, which was nearly removed the impurities, adding 0.5M $H_2O_2$. It was found that uranium could be selectively recovered (/removed) from TDSW.

본 연구는 우라늄 변환시설 운전 중에 발생된 우라늄 함유 슬러지를 가열 처리하여 분말 형태로 저장 중인 우라늄 함유 슬러지의 열분해 고체폐기물 (Thermal Decomposed Solid Waste of uranium-bearing sludge : TDSW)을 대상으로 TDSW의 용해, TDSW 질산 용해액의 알카리화에 의한 불순물 제거 및 탄산염 알카리화 용액의 산성화에 의한 U 선택적 제거/회수 특성 등을 규명하였다. TDSW의 용해는 질산용해가 탄산염 산화용해 보다 효과적이었다. 1M 질산에서 TDSW의 약 30wt%가 고체 잔류물로 불용해되었고, TDSW 내 함유 U은 99% 이상이 용해되었다. TDSW의 질산 용해액의 알카리화는 탄산염에 의한 알카리화가 불순물 제거 측면에서 보다 효과적이며, 탄산염 알카리화 (pH 약 9)에서 U과 공용해된 Ca, Al, Zn 및 Fe 등의 $98{\pm}1%$가 제거되었다. 그리고 불순물이 거의 제거된 알카리화 용액 (0.5 M $H_2O_2$ 첨가)의 산성화 (pH 약 3) 에서 U의 99% 이상을 회수할 수 있어 TDSW로부터 U을 선택적으로 제거/회수할 수 있었다.

Keywords

References

  1. J.H. Park, E.H. Kim, J.J. Park, T,J, Kim, W.M. Jung, K,C, Jung, J.H. Choi, and I.S. Chang, "Improvement of reconversion process for nuclear fuel", KAER/RR-1005/90 (1991)
  2. E.H. Lee, K.Y. Lee, D.Y. Chung, K.W. Kim, K.W. Lee and J.K. Moon, "Removal of uranium from U-bearing lime precipitate using dissolution and precipitation methods", J. Korean Radioact. Waste Soc., 10(2), pp.77-85 (2012) https://doi.org/10.7733/jkrws.2012.10.2.077
  3. D.S. Hwang, K.I. Lee, Y.D. Choi, S.T. Hwang, and J.H. Park, "Characteristics of lagoon sludge waste generated from an uranium conversion plant", J. Radioanal. Nucl. Chem., 260(2), pp.327-333 (2004). https://doi.org/10.1023/B:JRNC.0000027105.83084.c7
  4. J.H. Oh, D.S. Hwang, K.I. Lee, Y.D. Choi, S.T. Hwang, J.H. Park, and S.J. Park, "Stabilization of uranium sludge from a conversion plant through thermal decomposition", J. Ind. Eng. Chem., 12(5), pp.682-688 (2006).
  5. J.H Oh, D.S. Hwang, K.I. Lee, Y.D. Choi, S.T. Hwang, J.H. Park, S.J. Park, "Thermal decomposition and stabilization of the lagoon sludge solid waste after dissolution with water", J. Korean Radioact. Waste Soc., 3(3), pp. 249-256 (2005).
  6. "Regulation for the receiving of low- and intermediate radioactive waste", Korea Radioactive Waste Management Corporation (2009).
  7. "Regulation on the standards to estimate the cost of radioactive waste disposal and spent fuel management", Ministry of Knowledge Economy, Prescription No. 2011-197 (2011).
  8. International Atomic Energy Agency report, "Minimization of waste from uranium purification, enrichment and fuel fabrication", IAEA-TECDOC-1115, (1999).
  9. D.W. Shoesmith, "Used fuel and uranium dioxide dissolution studies- review", NWMO TR-2007-03, Nuclear Waste Management Organization, (2008).
  10. K.W. Kim, D.Y. Chung, H.B. Yang, J.K. Lim, E.H. Lee, K.C Song, and K. Song, "A conceptual process study for recovery of uranium alone from spent nuclear fuel by using high-alkaline carbonate media", Nucl. Tech., 166, pp.170-179 (2009).
  11. K.W. Kim, J.T. Hyun, E.H. Lee, G.I, Park, K.W. Lee, M.Y. Yoo, K.C Song, and J.K. Moon, "Recovery of uranium from $(U,Gd)O_2$ nuclear fuel scrap using dissolution and precipitation in carbonate media", J. Nucl. Mat., 418, pp.93-97 (2011). https://doi.org/10.1016/j.jnucmat.2011.06.019
  12. C.F.V. Mason, W.R. J.R. Turney, B.M. Thomson, N. Lu, P.A. Longman, and C.J. Chisholm-Brause, "Carbonate leaching of uranium in contaminated soils", Enviro. Sci. Tech., 31(10), pp.2707-2711 (1997). https://doi.org/10.1021/es960843j
  13. N. Asanuma, H. Tomiyasu, M. Harada, Y. Ikeda, and S. Hasegawa, "Anodic dissolution of $UO_2$ in aqueous alkaline solutions", J. Nucl. Sci. Tech., 37(5), pp.486-488 (2000). https://doi.org/10.1080/18811248.2000.9714921
  14. B. Hamrouni and M. Dhahbi, "Analytical aspects of silica in saline waters- application to desalination of brackish waters", Desalination 136, pp.225-232 (2001). https://doi.org/10.1016/S0011-9164(01)00185-0
  15. C.F. Baes, JR. and R.E. Mesmer, "The Hydrolysis of Cations", Robert E. Krieger Pub. Company, Malabar, Florida (1986).
  16. R.C. Merritt, "The extractive metallurgy of uranium", Colorado school of Mines Research Institute, US Atomic Energy Commission (1971).
  17. S.M. Pepper, L.F. Brodnax, S.E. Field, R.A. Zehnder, S.N. Valdez, and W.H. Runde, "Kinetic study of the oxidation dissolution of $UO_2$ in aqueous carbonate media", Ind. Eng. Chem. Res., 43, pp.8188-8193 (2004). https://doi.org/10.1021/ie049457y
  18. K.W. Kim, Y.H. Kim, SY. Lee, J.W. Lee, K.S. Joe, E.H. Lee, J.S. Kim, K. Song, and K.C. Song, "Precipitation Characteristics of Uranyl Ions at Different pHs Depending on the Presence of Carbonate Ions and Hydrogen Peroxide", Envion. Sci. Tech., 43, pp.2355-2361 (2009). https://doi.org/10.1021/es802951b
  19. J.A. Dean, "Lange's Handbook of Chemistry", 12th Edition, McGraw-Hill Book Company (1979).
  20. P.C. Debets, "X-ray diffraction data on hydrated uranium peroxide", J. Inorg. Nucl. Chem., 35, pp.727-730 (1963).
  21. K.W. Kim, Y.H. Kim, E.H. Lee, K. Song, and K.C. Song, "Study on electrolytic recoveries of carbonate salt and uranium from a uranyl peroxy carbonato complex solution generated from a carbonate-leaching process", Ind. Eng. Chem. Res., 49, pp.2085-2092 (2009).

Cited by

  1. Reprocessing of simulated voloxidized uranium-oxide SNF in the CARBEX process vol.51, pp.7, 2013, https://doi.org/10.1016/j.net.2019.05.020