Hostname: page-component-848d4c4894-cjp7w Total loading time: 0 Render date: 2024-07-03T08:27:40.633Z Has data issue: false hasContentIssue false
  • English
  • Français

Europium interaction with a vault backfill at high pH

Published online by Cambridge University Press:  05 July 2018

R. Telchadder ,
K. Smith  and
N. D. Bryan
R. Telchadder
Affiliation:
Centre for Radiochemistry Research, School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK
K. Smith
Affiliation:
Centre for Radiochemistry Research, School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK
N. D. Bryan*
Affiliation:
Centre for Radiochemistry Research, School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK
*
*E-mail: nick.bryan@manchester.ac.uk
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Batch experiments have been used to assess the sorption properties of a potential cementitious repository backfill, NRVB (Nirex reference vault backfill), using Eu3+ as a model trivalent radionuclide and ethylenediaminetetraacetic acid (EDTA) as a competing ligand. The NRVB is an effective scavenger of Eu from solution, with most sorbed within minutes onto the crushed material and less than 1.5% remaining in solution after one day (Rd values in the range 0.3–2.4 × 104 l kg−1). Ultrafiltration showed that nearly all of this remaining Eu (>94%) is attached to NRVB derived colloids or particulates that are mainly retained by a 100 kDa ultrafilter. High concentrations of EDTA (>0.01 M) reduced the extent of sorption at apparent equilibrium. The addition of EDTA to a pre-equilibrated system of Eu3+ and NRVB resulted in a temporary suspension of some Eu, but this very quickly returned to the solid phase. There is some irreversibility in these systems, with EDTA able to prevent removal of Eu(III) from solution, but unable to bring it back into solution under the same conditions.

Keywords

europium speciationgeological disposalNRVBmodelling vault backfill
Type
Research Article
Information
Mineralogical Magazine , Volume 76 , Issue 8 , December 2012 , pp. 3083 - 3093
Creative Commons
Creative Common License - CCCreative Common License - BY
© [2012] The Mineralogical Society of Great Britain and Ireland. This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY) licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2012

References

Aggarwal, S., Angus, M.J., Hibbert, R.C. and Tyson, A. (2001) Radionuclide Concentration in Cementitious Pore-Fluids Extracted Under High Pressure. AEA Technology plc report (for UK Nirex), report number AEAT/R/ENV/0231.Google Scholar
Baston, G.M.N., Berry, J.A., Brownsword, M., Heath, T.G., Tweed, C.J. and Williams, S.J. (1995) Sorption of plutonium and americium on repository backfill and geological materials relevant to the JNFL lowlevel radioactive waste repository at Rokkasho- Mura. Materials Research Society Symposium Proceedings, 353, 957–964.CrossRefGoogle Scholar
Braney, M.C. (1993) A study of the effects of an alkaline plume from a cementitious repository on geological materials. Journal of Contaminant Hydrology, 13, 379–402.CrossRefGoogle Scholar
Curti, E., Kulik, D.A. and Tits, J. (2005) Solid solutions of trace Eu(III) in calcite: thermodynamic evaluation of experimental data over a wide range of pH and pCO2. Geochimica et Cosmochimica Acta, 69, 1721–1737.CrossRefGoogle Scholar
Dario, M., Molera, M. and Allard, B. (2006) Sorption of europium on TiO2 and cement at high pH in the presence of organic ligands. Journal of Radioanalytical and Nuclear Chemistry, 270, 495–50.CrossRefGoogle Scholar
Department for Environment Fisheries and Rural Affairs (DEFRA), Department for Business, Enterprise and Regulatory Reform (BERR) and the Devolved Administration for Wales and Northern Ireland. (2008) Managing Radioactive Waste Safely: A Framework for Implementing Geological Disposal. DEFRA, London, 100 pp.Google Scholar
Francis, A.J., Cather, R. and Crossland, I.G. (1997) Development of the Nirex Reference Vault Backfill: Report on Current Status in 1994. UK Nirex report number S/97/014.Google Scholar
Heath, T.G. and Williams, S.J. (2005) Effects of Organic Complexants and Their Treatment in Performance Assessments. Serco report SA/ENV-0726.Google Scholar
Keith-Roach, M.J. (2008) The speciation, stability, solubility and biodegradation of organic co-contaminant radionuclide complexes: a review. Science of the Total Environment, 396, 1–11.CrossRefGoogle ScholarPubMed
Mandaliev, P., Dähn, R., Tits, J., Wehrli, B. and Wieland, E. (2010) EXAFS study of Nd(III) uptake by amorphous calcium silicate hydrates (C-S-H). Journal of Colloid and Interface Science, 342, 1–7.CrossRefGoogle Scholar
Martell, A.E. and Smith, R.M. (1974) Critical Stability Constants, Volume 1: Amino Acids. Plenum Press, New York.Google Scholar
McCarter, W., Crossland, I. and Chrisp, I. (2004) Hydration and drying of Nirex Reference Vault Backfill. Building and Environment, 39, 211–221.CrossRefGoogle Scholar
Means, J.L., Kucak, T. and Crerar, D.A. (1980) Relative degradation rates of NTA, EDTA and DTPA and environmental implications. Environmental Pollution Series B - Chemical and Physical, 1, 45–60.CrossRefGoogle Scholar
Nuclear Decommissioning Authority (2010) Geological Disposal: Near-field Evolution Status Report. NDA report NDA/RWMD/033, 2010.Google Scholar
Pitois, A., Ivanov, P., Abrahamsen, L., Bryan, N., Taylor, R. and Sims, E. (2008) Magnesium hydroxide bulk and colloid-associated 152Eu in alkaline environment: colloid character tion and sorption properties in the presence and absence of carbonate. Journal of Environmental Monitoring, 10, 315–324.CrossRefGoogle Scholar
Pointeau, I., Piriou, B., Fedoroff, M., Barthes, M., Marmier N. and Fromage, F. (2001) Sorption mechanisms of Eu3+ on CSH Phases of hydrated cements. Journal of Colloid and Interface Science, 236, 252–259.CrossRefGoogle Scholar
Pointeau, I., Landesman, C., Giffaut, E. and Reiller, P. (2004) Reproducibility of the uptake of U(VI) onto degraded cement pastes and calcium silicate hydrate phases. Radiochimica Acta, 92, 645–65.CrossRefGoogle Scholar
Pointeau, I., Coreau, N. and Reiller, P.E. (2008) Uptake of anionic radionuclides onto degraded cement pastes and competing effect of organic ligands. Radiochimica Acta, 96, 367–374.CrossRefGoogle Scholar
Ramsay, J.D.F., Avery, R.G. and Russel, P.J. (1988a) Physical characteristics and sorption behaviour of colloids generated from cementitious systems. Radiochimica Acta, 44/45, 119–124.Google Scholar
Ramsay, J.D.F., Russel, P.J. and Avery, R.G. (1988b) Colloids Related to Low and Intermediate Level Waste. UK Department of the Environment report DOE/RW/89/002.Google Scholar
Schlegel, M., Pointeau, I., Coreau, N. and Reiller, P. (2004) Mechanism of europium retention by calcium silicate hydrates: an EXAFS study. Environmental Science & Technology, 38, 4423–4431.CrossRefGoogle ScholarPubMed
Stumpf, T. and Fanghanel, T. (2002) A time-resolved laser fluorescence spectroscopy (TRLFS) study of the interaction of trivalent actinides (Cm(III)) with calcite. Journal of Colloid and Interface Science, 249, 119–122.CrossRefGoogle ScholarPubMed
Tits, J., Stumpf, T., Rabung, T., Wieland, E. and Fanghanel, T. (2003) Uptake of Cm(III) and Eu(III) by calcium silicate hydrates: a solution chemistry and time-resolved laser fluorescence spectroscopy study. Environmental Science & Technology, 37, 3568–3573.CrossRefGoogle ScholarPubMed
Tits, J., Wieland, E. and Bradbury, M.H. (2005) The effect of isosaccharinic acid and gluconic acid on the retention of Eu(III), Am(III) and Th(IV) by calcite. Applied Geochemistry, 20, 2082–2096.CrossRefGoogle Scholar
Toste, A.P., Osborn, B.C., Polach, K.J. and Lechnerfish, T.J. (1995) Organic analyses of an actual and simulated mixed waste - Hanford’s organic complexant waste revisited. Journal of Radioanalytical and Nuclear Chemistry, 194, 25–34.Google Scholar
Wieland, E. and Spieler, P. (2001) Colloids in the mortar backfill of a cementitious repository for radioactive waste. Waste Management, 21, 511–523.CrossRefGoogle ScholarPubMed
Wieland, E., Tits, J. and Bradbury, M.H. (2004) The potential effect of cementitious colloids on radionuclide mobilisation in a repository for radioactive waste. Applied Geochemistry, 19, 119–135.CrossRefGoogle Scholar
Zavarin, M., Roberts, S.K., Hakem, N., Sawvel, A.M. and Kersting, A.B. (2005) Eu(III), Sm(III), Np(V), Pu(V), and Pu(IV) sorption to calcite. Radiochimica Acta, 93, 93–102.CrossRefGoogle Scholar