ABSTRACT
The study of actinides under irradiation raised specific problems related to the more or less localized character of f electrons. The plutonium nucleus decays principally by alpha decay which produces an alpha particle and a recoil uranium nucleus. This induces defects that evolve with time in the material. Ideally, experimental data could be provided, but they are very scarce in the litterature, due to the difficulty to manipulate plutonium. Quantum scale studies are limited to less than one hundred of atoms, which is not enough to account for collision cascades that are responsible for the production of defects in plutonium alloys. In delta plutonium, electronic correlations are very strong, the specific heat coefficient is high, the Cauchy pressure is negative, the anisotropy of elastic constants is high and the thermal dilatation coefficient is negative.
