Abstract
Uranium nitride is an advanced fuel candidate for a wide variety of advanced nuclear reactors. This work summarizes the first characterization of UN kernels by Raman spectroscopy. First-principles density functional theory calculations were performed to predict the Raman spectra of uranium sesquinitride (U2N3), uranium dinitride (UN2), uranium mononitride (UN), uranium monocarbide (UC), as well as U-N-C (UN1-xCx) and a U-N-C-O mixture. A core–shell structure was identified by scanning electron microscopy and Raman spectroscopy imaging. A signal at ∼500 cm−1 was identified on the periphery of the core-shell structure, possibly corresponding to U2N3 and/or UN2. This signal broadens and shifts to 470 cm−1 because of the formation of UNC, UNCO or U2N3+x structures. The culmination of this work demonstrates the feasibility of using Raman spectroscopy to identify variations in composition and phases in UN kernels.
| Original language | English |
|---|---|
| Article number | 155050 |
| Journal | Journal of Nuclear Materials |
| Volume | 595 |
| DOIs | |
| State | Published - Jul 2024 |
Funding
This work was sponsored by the US Department of Energy (DOE) Office of Nuclear Energy's Advanced Fuels Campaign. Portions of this work were sponsored by the DOE National Nuclear Security Administration Office of Defense Nuclear Nonproliferation. Theoretical calculations research was supported by the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility at Oak Ridge National Laboratory. This research used resources belonging to the National Energy Research Scientific Computing Center (NERSC), a DOE Office of Science User Facility operated under Contract No. DE-AC02- 05CH11231.
Keywords
- DFT calculations
- Raman spectroscopy
- Uranium nitride