An investigation of the thermal stability of NdxYyZr1-x-yO2-δ inert matrix fuel materials

JOURNAL OF ALLOYS AND COMPOUNDS

卷:635

Article

Hayes, John R.¹  Grosvenor, Andrew P.¹  Saoudi, Mouna^2,3 

[1] Univ Saskatchewan, Dept Chem, Saskatoon, SK S7N 5C9, Canada

[2] Canadian Nucl Labs Ltd, Chalk River, ON K0J 1J0, Canada

[3] Atom Energy Canada Ltd, Ottawa, ON K1A 0S4, Canada

关键词: X-ray absorption spectroscopy;    Nuclear fuel;    Yttria-stabilized zirconia;    Structural characterization;    Inert matrix;    Fuel cycle;   

DOI  :  10.1016/j.jallcom.2015.02.022

来源: Elsevier

【 摘 要 】

An important step in achieving a closed uranium fuel cycle is to develop new inert matrix fuel (IMF) materials for use in the burn-up of transuranic species (TRU; i.e., Pu, Np, Am, Cm). Cubic fluorite zirconia (ZrO2) has ideal properties for use in IMF applications, but it is not stable at room temperature and must be stabilized through the addition of small amounts of dopants such as Y. While Y-substituted zirconia (YSZ) has been extensively studied, relatively little work has been done to investigate how the addition of an actinide to the YSZ system affects the properties of these materials. To this end, the long-range and local structures of a series of NdxYyZr1-x-yO2-delta compounds (Nd was used as a surrogate for Am) were studied using powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray absorption spectroscopy (XAS) at the Zr K-, Zr L-3-, Y K-, and Nd L-3-edges. The thermal stability of Nd-YSZ materials was also investigated by annealing the materials at temperatures ranging between 600 and 1400 degrees C. These studies showed that the thermal stability of the NdxYyZr1-x-yO2-delta system was improved by the addition of small amounts of Y (i.e. >= 5 at.%) to the system. Additionally, the XAS results showed that the local structure around Zr remained relatively constant; only changes in the second coordination shell were observed when the materials were annealed. These results strongly suggest that the addition of Y can significantly improve the thermal stability of zirconia-based IMFs. This study has also confirmed the importance and value of using advanced characterization techniques that are sensitive to the local structures of a material (i.e., XAS). (C) 2015 Elsevier B.V. All rights reserved.

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