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Synthesis and Characterization of Brannerite Compositions for MOX Residue Disposal

Published online by Cambridge University Press:  19 December 2016

D.J. Bailey ,
M.C. Stennett  and
N.C. Hyatt
D.J. Bailey*
Affiliation:
Immobilisation Science Laboratory, Department of Materials Science and Engineering, Univeristy of Sheffield, Mappin Street, Sheffield, S1 3JD, United Kingdom
M.C. Stennett
Affiliation:
Immobilisation Science Laboratory, Department of Materials Science and Engineering, Univeristy of Sheffield, Mappin Street, Sheffield, S1 3JD, United Kingdom
N.C. Hyatt
Affiliation:
Immobilisation Science Laboratory, Department of Materials Science and Engineering, Univeristy of Sheffield, Mappin Street, Sheffield, S1 3JD, United Kingdom
*
*(Email: [email protected])
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Abstract

Due to their high actinide content MOX residues require immobilization within a robust host matrix. Although it is possible to immobilize actinides in vitreous wasteforms; ceramic phases, such as brannerite (UTi2O6), are attractive due to their high waste loading capacity and relative insolubility. Brannerites Gd0.1U0.9Ti2O6, Ce0.1U0.9Ti2O6 and Gd0.1U0.81Ce0.09Ti2O6 were prepared using an oxide route. Charge compensation of trivalent cations was expected to occur via the oxidation of U (IV) to higher valence states (U (V) or U (VI)). Gd was added to act as a neutron absorber in the final Pu bearing wasteform and Ce was used as a structural surrogate for Pu. X-ray absorption spectroscopy showed that Ce (IV) was reduced to Ce (III) in all cases. X-ray powder diffraction of synthesized specimens found that the final phase assemblage was strongly affected by processing atmosphere (air or argon). Prototypical brannerite was formed in all compositions, secondary phases observed were found to vary according to processing atmosphere and stoichiometry. Microstructural analysis (SEM) of the sintered samples confirmed the results of the X-ray powder diffraction.

Keywords

Uceramicmicrostructure
Type
Articles
Information
MRS Advances , Volume 2 , Issue 10: Scientific Basis for Nuclear Waste Management XL , 2017 , pp. 557 - 562
Copyright
Copyright © Materials Research Society 2016 

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References

REFERENCES

Hyatt, N. C., “Plutonium management policy in the United Kingdom: The need for a dual track strategy,” Energy Policy, 99, (In press, 2016).Google Scholar
Wilson, P. D., The Nuclear Fuel Cycle: From Ore to Waste, 1st ed (Oxford University Press, Oxford, 1996).Google Scholar
Szymanski, J. T. and Scott, J. D., “A Crystal Structure Refinement of Synthetic Brannerite, UTi2O6, and Its Bearing on Rate of Alkaline-Carbonate Leaching of Brannerite in Ore,” Can. Mineral., 20, 271–279 (1982).Google Scholar
Ryerson, F. J. and Ebbinghaus, B., “Pyrochlore-Rich Titanate Ceramics for the Immobilization of Plutonium : Redox Effects on Phase Equilibria in Cerium- and Thorium- Substituted Analogs,” Lawrence Livermore National Laboratory Report, UCRL-ID-139092 (2000).Google Scholar
Zhang, Y., Lumpkin, G. R., Li, H., Blackford, M. G., Colella, M., Carter, M. L., and Vance, E. R., “Recrystallisation of amorphous natural brannerite through annealing : The effect of radiation damage on the chemical durability of brannerite,” J. Nucl. Mater., 350, 293–300 (2006).Google Scholar
Charalambous, F. A., Ram, R., Pownceby, M. I., Tardio, J., and Bhargava, S. K., “Chemical and microstructural characterisation studies on natural and heat treated brannerite samples,” Miner. Eng., 39, 276–288 (2012).Google Scholar
Lumpkin, G. R., “Alpha-decay damage and aqueous durability of actinide host phases in natural systems,” J. Nucl. Mater., 289 (1–2), 136–166 (2001).Google Scholar
Stennett, M. C., Freeman, C. L., Gandy, A. S., and Hyatt, N. C., “Crystal structure and non-stoichiometry of cerium brannerite: Ce0.975Ti 2O5.95,” J. Solid State Chem.,192, 172–178 (2012).Google Scholar
Vance, E. R., Watson, J. N., Carter, M. L., Day, R. A., and Begg, B. D., “Crystal Chemistry and Stabilization in Air of Brannerite, UTi2O6,” vol. 44, pp. 141–144, 2001.Google Scholar
James, M. and Watson, J. N., “The Synthesis and Crystal Structure of Doped Uranium Brannerite Phases U1−xMxTi2O6 (M=Ca2+, La3+, and Gd3+),” J. Solid State Chem., 165, 261–265 (2002).Google Scholar
Ravel, B. and Newville, M., “ATHENA, ARTEMIS, HEPHAESTUS: Data analysis for X-ray absorption spectroscopy using IFEFFIT,” Journal of Synchrotron Radiation, 12(4), 537–541 (2005).Google Scholar
Patchettt, J. E. and Nuffield, E. W., “Studies of Radioactive Compounds X- The Synthesis and Crystallography of Brannerite,” Can. Mineral., 6, 483–490 (1960).Google Scholar
Bailey, D. J., Stennett, M. C., and Hyatt, N. C., “Synthesis and Characterization of Brannerite Wasteforms for the Immobilization of Mixed Oxide Fuel Residues,” Procedia Chem., 21, 371–377 (2016).Google Scholar