First-principles study of bubble nucleation and growth behaviors in α U-Zr

Bubble nucleation and growth is responsible for swelling in metallic fuels such as U-Zr. Computational modeling is useful for understanding and ultimately developing mitigation strategies for the swelling behavior of the fuel. However, the relevant fundamental parameters are not currently available. In our previous work, the formation energy and migration barrier of uranium vacancies and interstitials in α U have been obtained by first-principles calculations, and the calculated diffusion activation energy agrees reasonably well with the experimental results, within 0.1 eV (Huang and Wirth 2011 J. Phys.: Condens. Matter 23 205402). In this paper, the formation energy and migration barrier of Xe, Zr, Pu, in addition to the binding energy of small vacancy clusters, Xe-vacancy clusters, and small interstitial clusters are investigated. These are among the essential data essential for the analysis and computational modeling of swelling in metallic nuclear fuel.