Diffusion characteristics of HTO and 99TcO4 in compacted Gaomiaozi (GMZ) bentonite

  • Tsuey-Lin Tsai
  • Shih-Chin Tsai
  • Yu-Hung Shih
  • Liang-Cheng Chen
  • Chuan-Pin Lee
  • Te-Yen Su


The characteristics of diffusion are essential to the transport of radionuclides through buffer/backfill materials, such as bentonite, which are commonly found in waste repositories. This study used through-diffusion techniques to investigate the diffusion behavior of HTO and 99TcO4 on GMZ bentonite of various densities. Diffusion rates were calculated by measuring the diffusion coefficients (D e, D a), plotting breakthrough curves and interpreting experiment data. The apparent and effective diffusion coefficients of HTO ranged from (1.68 ± 0.40) × 10−11 to (2.80 ± 0.62) × 10−11 m2/s and from (4.61 ± 1.28) × 10−12 to (16.2 ± 2.50) × 10−12 m2/s, respectively. The apparent and effective diffusion coefficients of 99TcO4 ranged from (5.26 ± 0.16) × 10−12 to (7.78 ± 0.43) × 10−12 m2/s and from (1.49 ± 0.002) × 10−12 to (4.16 ± 0.07) × 10−12 m2/s, respectively. The distribution coefficients of HTO and 99TcO4 ranged from (0.70 ± 0.12) × 10−2 to (1.36 ± 0.53) × 10−2 mL/g and from (1.12 ± 0.06) × 10−2 to (5.79 ± 2.22) × 10−2 mL/g, respectively. The D e and K d values were shown to decrease with an increase in the bulk dry density of compacted bentonite. Our results show that HTO and 99Tc could be considered non-sorbent radionuclides. The data obtained in this study provide a valuable reference for the safety assessment of waste repositories.


Distribution coefficient Apparent diffusion coefficient Effective diffusion coefficient Compacted bentonite Through-diffusion 



The authors would like to thank the Nuclear Backend Management Department at Taiwan Power Company for financially supporting this research.


  1. 1.
    Taiwan Power Company. Preliminary technical feasibility study for final disposal of spent nuclear fuel—2009 Progress Report (Summary), Taiwan, 2009.
  2. 2.
    T.K. Ikäheimonen, V.P. Vartti, E. Ilus et al., Technetium-99 in Fucusand seawater samples in the Finnish coastal area of the Baltic Sea, 1999. J. Radioanal. Nucl. Chem. 252(2), 309–313 (2002). doi: 10.1023/A:1015770423323 CrossRefGoogle Scholar
  3. 3.
    J.H. Chao, C.L. Tseng, C.L. Lee, Sequential extraction separation for determination of technetium-99 in radwastes by ICP-MS. J. Radioanal. Nucl. Chem. 251(1), 105–112 (2002). doi: 10.1023/A:1015054529857 CrossRefGoogle Scholar
  4. 4.
    Y.G. Chen, W.M. Ye, X.M. Yang et al., Effect of contact time, pH and ionic strength on Cd(II) adsorption from aqueous solution onto bentonite from Gaomiaozi, China. Environ. Earth Sci. 64(2), 329–336 (2011). doi: 10.1007/s12665-010-0850-6 CrossRefGoogle Scholar
  5. 5.
    Y.G. Chen, C.M. Zhu, Y.H. Sun et al., Adsorption of La(III) onto GMZ bentonite: effect of contact time, bentonite content, pH value and ionic strength. J. Radioanal. Nucl. Chem. 292(3), 1339–1347 (2012). doi: 10.1007/s10967-012-1612-6 CrossRefGoogle Scholar
  6. 6.
    X.D. Liu, T.A. Lug, G.P. Zhu, et al., Study on the properties of Gaomiaozi bentonite as the buffer/backfilling materials for HLW disposal (in Chinese). China Nuclear Information Centre, CNIC-01922 ECIT-000l, pp. 140–156.
  7. 7.
    Y.M. Liu, G.Q. Xu, S.F. Liu, et al., Study on the basic property of Gaomiaozi bentonite, Inner Mongolia (in Chinese) China Nuclear Information Centre, CNIC-01552 BRIUG-0054, pp. 1–16.
  8. 8.
    Y. Zhao, Z. Guo, J. Xu, 99TcO4 diffusion and sorption in compacted GMZ bentonite studied by capillary method. J. Radioanal. Nucl. Chem. 298, 147–152 (2013). doi: 10.1007/s10967-012-2329-2 CrossRefGoogle Scholar
  9. 9.
    D.J. Liu, X.H. Fan, Adsorption behavior of 99Tc on Fe, Fe2O3 and Fe3O4. J. Radioanal. Nucl. Chem. 264(3), 691–698 (2005). doi: 10.1007/s10967-005-0772-z CrossRefGoogle Scholar
  10. 10.
    H. Wang, T. Wu, J. Chen et al., Effect of humic acid contact time on the diffusion of Re(VII) in GMZ bentonite. Nucl. Sci. Tech. 26, S10314-1–S10314-5 (2015). doi: 10.13538/j.1001-8042/nst.26.S10314 Google Scholar
  11. 11.
    G.P. Xiao, T. Wu, H. Wang et al., Effect of inorganic salts on Se(IV) and Re(VII) diffusions in bentonite. Nucl. Sci. Tech. 26, 050302-1–050302-5 (2015). doi: 10.13538/j.1001-8042/nst.26.050302 Google Scholar
  12. 12.
    H. Vinšová, P. Večerník, V. Jedináková-Křížová, Sorption characteristics of 99Tc onto bentonite material with different additives under anaerobic conditions. Radiochim. Acta 94, 435–440 (2006). doi: 10.1524/ract.2006.94.8.435 Google Scholar
  13. 13.
    X. Wang, Z. Tao, Diffusion of 99TcO4 in compacted bentonite: effect of pH, concentration, density and contact time. J. Radioanal. Nucl. Chem. 260(2), 305–309 (2004). doi: 10.1023/B:JRNC.0000027101.01834.1b CrossRefGoogle Scholar
  14. 14.
    T.E. Eriksen, A. Jacobsson, Diffusion in clay. Experimental techniques and theoretical models. SKB TR 84-05, 1984, Svensk Kärnbränslehantering AB, Sweden.
  15. 15.
    C. Paul, Compilation of radionuclide sorption coefficients for performance assessment, SKB R-97-13, 1997, Svensk Kärnbränslehantering AB, Sweden.
  16. 16.
    J. Crank, The mathematics of diffusion, 2nd edn. (Oxford, London (UK): Clarendon Press, 1975), pp. 50–52.
  17. 17.
    C.P. Lee, S.C. Tsai, Y.L. Jan et al., Sorption and diffusion of HTO and cesium in crushed granite compacted to different lengths. J. Radioanal. Nucl. Chem. 275(2), 371–378 (2008). doi: 10.1007/s10967-007-6976-7 CrossRefGoogle Scholar
  18. 18.
    S.W. Wang, Y.H. Dong, M.L. He et al., Characterization of GMZ bentonite and its application in the adsorption of Pb(II) from aqueous solutions. Appl. Clay Sci. 43, 164–171 (2009). doi: 10.1016/j.clay.2008.07.028 CrossRefGoogle Scholar
  19. 19.
    Data report for the safety assessment SR-Site, SKB TR 10-52, p.p 163-169, December 2010, Svensk Kärnbränslehantering AB, Sweden.
  20. 20.
    J.Y. Li, W. Dai, G.P. Xiao et al., Pertechnetate diffusion in GMZ bentonite. J. Radioanal. Nucl. Chem. 293, 763–767 (2012). doi: 10.1007/s10967-012-1733-y CrossRefGoogle Scholar
  21. 21.
    Z. Szántó, É. Svingor, M. Molnár et al., Diffusion of H-3, Tc-99, I-125, Cl-36 and Sr-85 in granite, concrete and bentonite. J. Radioanal. Nucl. Chem. 252(1), 133–138 (2002). doi: 10.1023/A:1015256308843 CrossRefGoogle Scholar
  22. 22.
    J.W. Yu, I. Neretnieks. Diffusion and sorption properties of radionuclides in compacted bentonite, SKB TR 97-12, 1997, Svensk Kärnbränslehantering AB, Sweden.
  23. 23.
    Y.Y. Liu, C.X. Liu, R.K. Kukkadapu et al., 99Tc(VII) retardation, reduction, and redox rate scaling in naturally reduced sediments. Environ. Sci. Technol. 49, 13403–13412 (2015). doi: 10.1021/acs.est.5b03273 CrossRefGoogle Scholar

Copyright information

© Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Chinese Nuclear Society, Science Press China and Springer Science+Business Media Singapore 2017

Authors and Affiliations

  • Tsuey-Lin Tsai
    • 1
  • Shih-Chin Tsai
    • 2
  • Yu-Hung Shih
    • 1
  • Liang-Cheng Chen
    • 1
  • Chuan-Pin Lee
    • 3
  • Te-Yen Su
    • 1
  1. 1.Chemistry DivisionInstitute of Nuclear Energy ResearchTaoyuanChina
  2. 2.Nuclear Science and Technology Development CenterNational Tsing Hua UniversityHsinchuChina
  3. 3.Department of Earth SciencesNational Cheng Kung UniversityTainanChina

Personalised recommendations