This standard specifies a method for the determination of the apparent density and vibrated density of free-flowing nuclear fuel powder used for pelletizing and sintering of nuclear fuel pellets. The powder can consist of grains, granules, spheres or other types of particle. The method can be applied to fuel powders such as UO2, PuO2, ThO2 and powder mixtures such as UO2-PuO2 and UO2-Gd2O3.