Plutonium and neptunium incorporation in zirconolite
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Date
1997
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Publisher
Materials Research Society
Abstract
The incorporation of Pu and Np in zirconolite (CaZrTi2O7) has been investigated over a range of redox conditions. Zirconolite formulations designed to favour either trivalent or tetravalent Pu and Np were prepared by limiting the amount of charge compensating additives available to maintain electroneutrality. From near-edge X-ray absorption spectroscopy the Pu valence state was found to vary with the processing atmosphere, from completely tetravalent when fired in air, and located on either the Ca or Zr sites, to trivalent, when substituted on the Ca site after annealing in 3.5% H2/N2. Np was predominantly tetravalent over the range of redox conditions examined and was readily incorporated on either of zirconolite's Ca or Zr sites. The charge compensation mechanisms at work in different zirconolites are also discussed. © Materials Research Society 1997
Description
Physical copy held by ANSTO at DDC: 621.4838/31.
Abstract also available online at https://doi.org/10.1557/PROC-465-325.
Keywords
Plutonium, Neptunium, Zirconolite, Redox process, Absorption, Annealing, Air, Valence
Citation
Begg, B. D., Vance, E. R., Day, R. A., Hambley. M., & Conradson, S. D. (1996). Plutonium and neptunium incorporation in zirconolite. Paper presented to the Scientific Basis for Nuclear Waste Management XX, 2-6 December 1996, Boston, Massachachuetts, U. S. A. In Gray, W. J. & Triay, I. R. (Eds.), Material Research Society Symposium Proceedings, Symposium held December 2-6 , 1996, Boston, Massachusetts, U. S. A., (Vol. 465, pp. 325-332).