Molecular dynamics simulations of grain boundary thermal resistance in UO sub(2)

• Published in: Journal of nuclear materials Vol. 452; no. 1-3; pp. 364 - 369
• Main Authors: Chen, Tianyi, Chen, Di, Sencer, Bulent H, Shao, Lin
• Format: Journal Article
• Language: English
• Published: 01.09.2014
• ISSN: 0022-3115
• DOI: 10.1016/j.jnucmat.2014.05.035

By means of molecular dynamics (MD) simulations, we have calculated Kaptiza resistance of UO sub(2) with or without radiation damage. For coincident site lattice boundaries of different configurations, the boundary thermal resistance of unirradiated UO sub(2) can be well described by a parameter-reduced formula by using boundary energies as variables. We extended the study to defect-loaded UO sub(2) by introducing damage cascades in close vicinity to the boundaries. Following cascade annealing and defect migrations toward grain boundaries, the boundary energy increases and so does Kaptiza resistance. The correlations between these two still follow the same formula extracted from the unirradiated UO sub(2). The finding will benefit multi-scale modeling of UO sub(2) thermal properties under extreme radiation conditions by combining effects from boundary configurations and damage levels.