TY - JOUR
T1 - Effect of pores and He bubbles on the thermal transport properties of UO2 by molecular dynamics simulation
AU - Lee, C. W.
AU - Chernatynskiy, A.
AU - Shukla, P.
AU - Stoller, R. E.
AU - Sinnott, S. B.
AU - Phillpot, S. R.
N1 - Funding Information:
CWL and SRP were support by the on Physics-Based Models for 3D Predictive Simulation of Fast Reactor Fuel Performance. This work was co-authored by subcontractor (AC) of the NEAMS FOA Project U.S. Government under DOE Contract No. DE-AC07-05ID14517 , under the Energy Frontier Research Center ( Office of Science, Office of Basic Energy Science , FWP 1356 ). Accordingly, the U.S. Government retains and the publisher (by accepting the article for publication) acknowledges that the U.S. Government retains a nonexclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for U.S. Government purposes. SBS acknowledges the support of the Air Force Office of Scientific Research through Award Number FA9550-12-1-0456 . RES acknowledges the support of U.S. Department of Energy, Office of Fusion Energy Sciences under contract with UT-Battelle, LLC .
Publisher Copyright:
© 2014 Elsevier B.V. All rights reserved.
PY - 2015/1
Y1 - 2015/1
N2 - The thermal conductivities of UO2 single crystals containing nanoscale size pores and He gas bubbles are calculated using non-equilibrium molecular dynamics as a function of pore size and gas density in the bubble. As expected, the thermal conductivity decreases as pore size increases, while the decrease in thermal conductivity is determined to be more substantial than the predictions of traditional analytical models by Loeb and Maxwell-Eucken. However, the recent model of Alvarez, which is applicable when the phonon mean-free path is comparable to the pore size, is able to quantitatively reproduce the simulation results. The thermal conductivity of UO2 of the small pores considered here is reduced further when the pore is filled with He gas. This surprising result is due to the penetration of the helium atoms into the lattice where they act as phonon scattering centers.
AB - The thermal conductivities of UO2 single crystals containing nanoscale size pores and He gas bubbles are calculated using non-equilibrium molecular dynamics as a function of pore size and gas density in the bubble. As expected, the thermal conductivity decreases as pore size increases, while the decrease in thermal conductivity is determined to be more substantial than the predictions of traditional analytical models by Loeb and Maxwell-Eucken. However, the recent model of Alvarez, which is applicable when the phonon mean-free path is comparable to the pore size, is able to quantitatively reproduce the simulation results. The thermal conductivity of UO2 of the small pores considered here is reduced further when the pore is filled with He gas. This surprising result is due to the penetration of the helium atoms into the lattice where they act as phonon scattering centers.
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U2 - 10.1016/j.jnucmat.2014.09.052
DO - 10.1016/j.jnucmat.2014.09.052
M3 - Article
AN - SCOPUS:84908088023
SN - 0022-3115
VL - 456
SP - 253
EP - 259
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
ER -