Skip to main content
Log in

Phase distribution of uranium in matrices for immobilization of the rare earth–actinide fraction of high-level waste

  • Published:
Radiochemistry Aims and scope

Abstract

The uranium distribution in candidate host materials for the rare earth–actinide fraction was studied. The compositions of the materials were set so as to obtain artificial phases with the structures of pyrochlore Ln2(Ti,Zr)2O7 (space group Fd3m, Z = 8) and of monoclinic (P21, Z = 4) and rhombic (Fddd, Z = 16) titanates with the formulas Ln2Ti2O7 and Ln4Ti9O24, respectively, where Ln is a mixture of lanthanides simulating the wastes. The uranium content was varied from 3.5 to 5.5 wt %. In some cases, an equiatomic amount of calcium was introduced into the charge to check the possibility of the replacement of two Ln3+ cations by the Ca2+ + U4+ pair. Samples were prepared by sintering of the oxide charge or by its melting and crystallization of the melt. Along with the prevalent target compounds, the products contained uranium and lanthanide oxides, titanate of Ln and U with brannerite structure, Ln titanosilicates, and other phases. The main uranium concentrators in the samples are pyrochlore, oxides, and brannerite; small amounts of uranium (1–2 wt %) are incorporated in titanosilicates and rhombic titanate. The addition of calcium does not influence the capacity of monoclinic and rhombic titanates for uranium. Based on these data and the results of previous studies, a conclusion is made that rhombic titanate Ln4Ti9O24 and brannerite (Ln,U)Ti2O6 deserve an additional study as candidate host materials for the rare earth–actinide fraction.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Shoup, S.S., Bamberger, C.E., Haverlock, T.J., and Peterson, J.R., J. Nucl. Mater., 1997, vol. 240, pp. 112–117.

    Article  CAS  Google Scholar 

  2. Laverov, N.P., Yudintsev, S.V., Stefanovsky, S.V., and Ewing, R.Ch., Dokl. Earth Sci., 2012, vol. 443, no. 2, pp. 526–531.

    Article  CAS  Google Scholar 

  3. Yudintsev, S.V., Gotovchikov, V.T., Omel’yanenko, B.I., et al., Geoekologiya, 2013, no. 4, pp. 383–392.

    Google Scholar 

  4. Yudintsev, S.V., Stefanovsky, S.V., and Nikonov, B.S., Dokl. Earth Sci., 2014, vol. 454, no. 1, pp. 54–58.

    Article  CAS  Google Scholar 

  5. Yudintsev, S.V., Aleksandrova, E.V., Livshits, T.S., et al., Dokl. Earth Sci., 2014, vol. 458, no. 2, pp. 1281–1284.

    Article  CAS  Google Scholar 

  6. Yudintsev, S.V. and Stefanovsky, S.V., Dokl. Chem., 2015, vol. 460, no. 1, pp. 21–25.

    Article  CAS  Google Scholar 

  7. Yudintsev, S.V., Dokl. Earth Sci., 2015, vol. 460, no. 2, pp. 130–136.

    Article  CAS  Google Scholar 

  8. Yudintsev, S.V., Stefanovsky, S.V., Nikonov, B.S., et al., Radiochemistry, 2015, vol. 57, no. 2, pp. 187–199.

    Article  CAS  Google Scholar 

  9. Yudintsev, S.V., Livshits, T.S., Zhang, J., and Ewing, R.C., Dokl. Earth Sci., 2015, vol. 461, no. 1, pp. 247–253.

    Article  CAS  Google Scholar 

  10. PDFWIN-2, Newton Square (PA): Int. Centre for Diffraction Data, 1999.

  11. Skapin, S.D., Kolar, D., and Suvorov, D., Solid State Sci., 1999, vol. 1, pp. 245–255.

    Article  CAS  Google Scholar 

  12. Gong, W. and Zhang, R.J., J. Alloys Compd., 2013, vol. 548, pp. 216–221.

    Article  CAS  Google Scholar 

  13. James, M. and Watson, J.N., J. Solid State Chem., 2002, vol. 165, no. 2, pp. 261–265.

    Article  CAS  Google Scholar 

  14. James, M., Carter, M.L., and Watson, J.N., J. Solid State Chem., 2003, vol. 174, no. 2, pp. 329–333.

    Article  CAS  Google Scholar 

  15. Vance, E.R., Zhang, Y., and Zhang, Z., J. Nucl. Mater., 2010, vol. 400, pp. 8–14.

    Article  CAS  Google Scholar 

  16. Nastren, C., Jardin, R., Somers, J., et al., J. Solid State Chem., 2009, vol. 182, pp. 1–7.

    Article  Google Scholar 

  17. Rak, Zs., Ewing, R.C., and Becker, U., J. Phys. Condens. Matter, 2013, vol. 25, pp. 1–10.

    Article  Google Scholar 

  18. Stewart, M.W.A., Vance, E.R., Jostsons, A., et al., Mater. Res. Soc. Symp. Proc., 2002, vol. 713, pp. 381–388.

    CAS  Google Scholar 

  19. Strachan, D.M., Scheele, R.D., Buck, E.C., et al., J. Nucl. Mater., 2005, vol. 345, pp. 109–135.

    Article  CAS  Google Scholar 

  20. Thomas, B.S. and Zhang, Y., Radiochim. Acta, 2003, vol. 91, pp. 463–472.

    Article  CAS  Google Scholar 

  21. Lumpkin, G.R., Elements, 2006, vol. 2, pp. 365–372.

    Article  CAS  Google Scholar 

  22. Charalambous, F.A., Synthesis, characterisation and dissolution of brannerite, a uranium titanate mineral, PhD Thesis, Australia: RMIT, 2013. 223 p.

    Google Scholar 

  23. Laverov, N.P., Velichkin, V.I., Omel’yanenko, B.I., et al., Izolyatsiya otrabotavshikh yadernykh materialov: geologo-geokhimicheskie osnovy (Isolation of Spent Nuclear Materials: Geological and Geochemical Principles), Moscow: Inst. Fiziki Zemli Ross. Akad. Nauk, 2008.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to S. V. Yudintsev.

Additional information

Original Russian Text © S.V. Yudintsev, S.V. Stefanovsky, O.I. Stefanovskaya, B.S. Novikov, M.S. Nikol’skii, 2015, published in Radiokhimiya, 2015, Vol. 57, No. 6, pp. 547–555.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Yudintsev, S.V., Stefanovsky, S.V., Stefanovskaya, O.I. et al. Phase distribution of uranium in matrices for immobilization of the rare earth–actinide fraction of high-level waste. Radiochemistry 57, 640–651 (2015). https://doi.org/10.1134/S1066362215060120

Download citation

  • Received:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1134/S1066362215060120

Keywords

Navigation