Synthesis of phase-pure U₂N₃ microspheres and its decomposition into UN

Journal Article · Fri Dec 12 00:00:00 EST 2014 · Inorganic Chemistry

DOI:https://doi.org/10.1021/ic502457n· OSTI ID:1265341

Silva, Chinthaka M. ^[1]; Hunt, Rodney Dale ^[1]; Snead, Lance Lewis ^[1]; Terrani, Kurt A. ^[1]

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1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division

Uranium mononitride (UN) is important as a nuclear fuel. Fabrication of UN in its microspherical form also has its own merits since the advent of the concept of accident-tolerant fuel, where UN is being considered as a potential fuel in the form of TRISO particles. But, not many processes have been well established to synthesize kernels of UN. Therefore, a process for synthesis of microspherical UN with a minimum amount of carbon is discussed herein. First, a series of single-phased microspheres of uranium sesquinitride (U₂N₃) were synthesized by nitridation of UO₂+C microspheres at a few different temperatures. Resulting microspheres were of low-density U₂N₃ and decomposed into low-density UN. The variation of density of the synthesized sesquinitrides as a function of its chemical composition indicated the presence of extra (interstitial) nitrogen atoms corresponding to its hyperstoichiometry, which is normally indicated as α-U₂N₃. Average grain sizes of both U₂N₃ and UN varied in a range of 1–2.5 μm. In addition, these had a considerably large amount of pore spacing, indicating the potential sinterability of UN toward its use as a nuclear fuel.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE)
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1265341
• Journal Information: Inorganic Chemistry, Vol. 54, Issue 1; ISSN 0020-1669
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
uranium nitride kernels
uranium sesquinitride
uranium mononitride