The grain-size effect on thermal conductivity of uranium dioxide
- Idaho National Lab. (INL), Idaho Falls, ID (United States)
- Idaho National Lab. (INL), Idaho Falls, ID (United States); Rensselaer Polytechnic Inst., Troy, NY (United States)
- Rensselaer Polytechnic Inst., Troy, NY (United States)
- Univ. of Florida, Gainesville, FL (United States)
We have investigated the grain-boundary scattering effect on the thermal transport behavior of uranium dioxide (UO2). The polycrystalline samples having different grain-sizes (0.125, 1.8, and 7:2 µm) have been prepared by a spark plasma sintering technique and characterized by x-ray powder diffraction, scanning electron microscope, and Raman spectroscopy. The thermal transport properties (the thermal conductivity and thermoelectric power) have been measured in the temperature range of 2–300 K, and the results were analyzed in terms of various physical parameters contributing to thermal conductivity in these materials in relation to grain-size. We show that thermal conductivity decreases systematically with lowering grain-size in the temperatures below 30 K, where the boundary scattering dominates the thermal transport. At higher temperatures, more scattering processes are involved in the heat transport in these materials, making the analysis difficult. We determined the grain-boundary Kapitza resistance that would result in the observed increase in thermal conductivity with grain-size and compared the value with Kapitza resistances calculated for UO2 using molecular dynamics from the literature.
- Research Organization:
- Idaho National Laboratory (INL), Idaho Falls, ID (United States)
- Sponsoring Organization:
- USDOE Office of Nuclear Energy (NE)
- Grant/Contract Number:
- AC07-05ID14517; Advanced Fuel Campaign
- OSTI ID:
- 1581148
- Alternate ID(s):
- OSTI ID: 1567715
- Report Number(s):
- INL/JOU-19-54003-Rev000; TRN: US2101861
- Journal Information:
- Journal of Applied Physics, Vol. 126, Issue 12; ISSN 0021-8979
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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