A First-principles study on heat capacity of actinide dioxides

Nakamura, Hiroki  ; Machida, Masahiko  

Actinide dioxides are the main components of mixed oxide nuclear fuel (MOX). Therefore, in order to develop MOX fuels, we have to have a detailed knowledge of actinide dioxides. However, the determination of their properties through experiments is not easy owing to limitations associated with their handling. In such cases, numerical simulations are effective for the evaluation of the properties of actinide dioxides. So far, we calculated the heat capacity of plutonium dioxide using first-principles density functional theory and successfully reproduced the observed values. In this paper, we apply this calculation method to other actinide dioxides, such as UO, NpO and AmO, and evaluate their heat capacity. In conclusion, our calculation method is available to evaluate heat capacity of actinide dioxides.