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

Korean Radioactive Waste Society (한국방사성폐기물학회)
권호 표지
DOI QR코드

DOI QR Code

Sorption of Tc(IV) in Saline Solutions - II. Sorption on MX-80, Illite, Shale and Limestone in Na-Ca-Cl Solutions

  • Shinya Nagasaki (McMaster University) ;
  • Zhiwei Zheng (McMaster University) ;
  • Jianan Liu (McMaster University) ;
  • Jieci Yang (McMaster University) ;
  • Tammy (Tianxiao) Yang (Nuclear Waste Management Organization)
  • Received : 2024.04.26
  • Accepted : 2024.06.11
  • Published : 2024.09.30
Download PDF
⟨ Previous Next ⟩

Abstract

Technetium has been identified as an element of interest for the safety assessment of a deep geological repository for used nuclear fuel. In this study, the sorption of Tc(IV) onto MX-80 bentonite, illite, and shale in ionic strength (I) 0.1-6 mol·kgw-1 (m) Na-Ca-Cl solutions at pHm = 4-9 and limestone at pHm = 5-9 was studied. Tc(IV) sorption on MX-80 increased with pHm from 4 to 6, reached the maximum at pHm = 6-7, and then gradually decreased with pHm from 7 to 9. Tc(IV) sorption on illite gradually increased with pHm from 4 to 7, and then decreased as pHm increased. The sorption properties of Tc(IV) on shale were quite similar to those on illite. Tc(IV) sorption on limestone slightly increased with pHm from 5 to 6 and then seemed to be constant at pHm = 6-9. Tc(IV) sorption on all four solids was independent of ionic strength (0.1-6 m). The 2 site protolysis non-electrostatic surface complexation and cation exchange model successfully simulated the sorption of Tc(IV) onto MX-80 and illite and the optimized values of surface complexation constants were estimated.

Keywords

Acknowledgement

This work was funded by the Nuclear Waste Management Organization of Canada. The authors appreciate Prof. Koichiro Takao at the Tokyo Institute of Technology and Dr. Taishi Kobayashi at Kyoto University for their valuable comments on the experimental methods and the procedures for confirmation of the reduction of Tc(VII) to Tc(IV).

References

  1. S. Nagasaki, Z. Zhiwei, J. Liu, J. Yang, and T. Yang, "Sorption of Tc(IV) in Saline Solutions - I. Sorption on MX-80 and Granite in Ca-Na-Cl Solutions", J. Nucl. Fuel Cycle Waste Technol., 22(3), 287-299 (2024).
  2. F.B. Walton, J. Paquette, J.P.M. Ross, and W.E. Lawrence, "Tc(IV) and Tc(VII) Interactions With Iron Oxyhydroxides", Nucl. Chem. Waste Manag., 6(2), 121-126 (1986).
  3. P. Tkac, R. Kopunee, F. Macasek, and S. Skraskova, "Sorption of Tc(IV) and Tc(VII) on Soils: Influence of Humic Substances", J. Radioanal. Nucl. Chem., 246(3), 527-531 (2000).
  4. Y. Uezu, H. Watanabe, M. Takeishi, and K. Shinohara, "Distribution and Migration of 99Tc in Surface Soil", JNC Tech. Rev., 12, 139-144 (2001) (in Japanese).
  5. S. Kumar, N. Rawat, A.S. Kar, B.S. Tomar, and V.K. Manchanda, "Effect of Humic Acid on Sorption of Technetium by Alumina", J. Hazard. Mater., 192(3), 1040-1045 (2011).
  6. R.J. Hallam, N.D.M. Evans, and S.L. Jain, "Sorption of Tc(IV) to Some Geological Materials With Reference to Radioactive Waste Disposal", Mineral. Mag., 75(4), 2439-2448 (2011).
  7. J.K. Fredrickson, J.M. Zachara, D.W. Kennedy, R.K. Kukkadapu, J.P. McKinley, S.M. Heald, C. Liu, and A.E. Plymale, "Reduction of TcO4- by Sediment-associated Biogenic Fe(II)", Geochim. Cosmochim. Acta, 68(15), 3171-3187 (2004).
  8. E. Yalcintas, A.C. Scheinost, X. Gaona, and M. Altmaier, "Systematic XAS Study on the Reduction and Uptake of Tc by Magnetite and Mackinawite", Dalton Trans., 45, 17874-17885 (2016).
  9. D.M. Rodriguez, N. Mayordomo, A.C. Scheinost, D. Schild, V. Brendler, K. Muller, and T. Stumpf, "New Insight Into 99Tc(VII) Removal by Pyrite: A Spectroscopic Approach", Environ. Sci. Technol., 54(5), 2678-2687 (2020).
  10. N. Mayordomo, D.M. Rodriguez, D. Schild, K. Molodtsov, E.V. Johnstone, R. Hubner, S.S.A. Azzam, V. Brendler, and K. Muller, "Technetium Retention by Gamma Alumina Nanoparticles and the Effect of Sorbed Fe2+", J. Hazard. Mater., 388, 122066 (2020).
  11. N. Mayordomo, D.M. Rodriguez, A. Rossberg, H. Foerstendorf, K. Heim, V. Brendler, and K. Muller, "Analysis of Technetium Immobilization and Its Molecular Retention Mechanisms by Fe(II)-Al(III)-Cl Layered Double Hydroxide", Chem. Eng. J., 408, 127265 (2021).
  12. D.M. Rodriguez, N. Mayordomo, D. Schild, S.S.A. Azzam, V. Brendler, K. Muller, and T. Stumpf, "Reductive Immobilization of 99Tc(VII) by FeS2: The Effect of Marcasite", Chemosphere, 281, 130904 (2021).
  13. K. Schmeide, A. Rossberg, F. Bok, S.S.A. Azzam, S. Weiss, and A.C. Scheinost, "Technetium Immobilization by Chukanovite and Its Oxidative Transformation Products: Neutral Network Analysis of EXAFS Spectra", Sci. Total Environ.,770, 145334 (2021).
  14. M.Y. Hobbs, S.K. Frape, O. Shouakar-Stash, and L.R. Kennell. Regional Hydrogeochemistry- Southern Ontario, Nuclear Waste Management Organization Technical Report, NWMO DGR-TR-2011-12 (2011).
  15. P. Vilks and T. Yang. Sorption of Selected Radionuclides on Sedimentary Rocks in Saline Conditions - Updated Sorption Values, Nuclear Waste Management Organization Technical Report, NWMO-TR-2018-03 (2018).
  16. P. Bertetti. Determination of Sorption Properties for Sedimentary Rocks Under Saline Reducing Conditions - Key Radionuclides, Nuclear Waste Management Organization Technical Report, NWMO-TR-2016-08 (2016).
  17. J. Hower and T.C.Mowatt, "The Mineralogy of Illites and Mixed -Layer Illite/Montmorillonite", Am. Mineral., 51, 825-854 (1966).
  18. S. Pivovarov, "Physico-Chemical Modeling of Heavy Metals (Cd, Zn, Cu) in Natural Environments", in: Encyclopedia of Surface and Colloid Science, 2004 Update Supplement, P. Somasundaran, ed., 468-492, CRC Press, Boca Raton (2004).
  19. A. Walker, J. Racette, T. Saito, T. Yang, and S. Nagasaki, "Sorption of Se(-II) on Illite, MX-80 Bentonite, Shale, and Limestone in Na-Ca-Cl Solutions", Nucl. Eng. Technol., 54(5), 1616-1622 (2022).
  20. Nuclear Energy Agency, Clay Club Catalogue of Characteristics of Argillaceous Rocks - 2022 Update, OECD Publishing, Paris (2022).
  21. Nuclear Waste Management Organization. OPG's Deep Geologic Repository for Low & Intermediate Level Waste, NWMO Technical Report, NWMO DGR-TR-2011-24 (2011).
  22. B. Grambow, M. Fattahi, G. Montavon, C. Moisan, and E. Giffaut, "Sorption of Cs, Ni, Pb, Eu(III), Am(III), Cm, Ac(III), Tc(IV), Th, Zr, and U(IV) on MX 80 Bentonite: An Experimental Approach to Assess Model Uncertainty", Radiochim. Acta, 94(9-11), 627-636 (2006).
  23. E. Colas, O. Riba, and V. Alba. Radionuclide Solubility Calculations (Phase 2), Nuclear Waste Management Organization Technical Report, NWMO-TR-2022-11 (2022).
  24. L. Ciavatta, "The Specific Interaction Theory in Evaluating Ionic Equilibria", Ann. Chim., (Rome), 70, 551- 567 (1980).
  25. Japan Atomic Energy Agency. April 27 2021. "Thermodynamic DataBase." JAEA hompage. Access Feb. 20 2024. Available from: https://www.jaea.go.jp/04/tisou/english/database/database.html.