Density-functional theory (DFT) simulations are applied to obtain elastic, strength, and EOS properties of actinide metals under extreme conditions. In this presentation, we will show our recent study on temperature effects of the properties of solids of actinide metals. For example of low temperature uranium (U) solids, elastic constants are calculated directly from the DFT total energy for the ground-state phase in a wide pressure range. For higher temperature U solids, we are applying a recent scheme to calculate temperature-dependent phonon dispersions through the self-consistent ab initio lattice dynamics (SCAILD) technique. This scheme is particular important for the higher temperature phases that the elasticity cannot be analogously obtained because of its mechanical instability at lower temperatures. From these SCAILD phonon dispersions we then extract the elastic constants from the slopes approaching the Γ point. In addition, the phonon density of states of U obtained from SCAILD/DFT calculations have been used to parameterize a double Debye model for its ion-thermal free energy. We will discuss the ramification of this new Debye model on our development of multi-phase uranium EOS.