First Principles Study of Point Defects in Uranium Dioxide
To clarify the origin of a characteristic fine grain structure formed under the high burn-up of the nuclear fuel, the comprehensive first-principles calculations for UO2 containing various types of point defect have been performed by the PAW-GGA+U with lattice relaxation for supercells containing 1, 2 and 8 unit cells of UO2. The electronic structure, the atomic displacement and the defect formation energies of defective systems are obtained, and the effects of supercell size on these properties are discussed. Based on this relatively high precise self-consistent formation energies dataset, thermodynamic properties of various types of point defects in UO2 are further investigated in the framework of the point defects model.
Young Won Chang, Nack J. Kim and Chong Soo Lee
Y. Chen et al., "First Principles Study of Point Defects in Uranium Dioxide", Materials Science Forum, Vols. 561-565, pp. 1971-1974, 2007