Process for manufacturing improved nuclear fuel pellets, including compacting ceramic powder in the Compaction chamber of a pelletizing machine with only the lower punch moving on compaction, wherein the walls of the compaction chamber are widened on at least part of their height in the direction of a diameter increase towards the die-bearing table.
These ceramic pellets generally consist of uranium, plutonium, thorium, etc.. in oxide, nitride, carbide or other form. The manufacturing process for these pellets comprises the compression of appropriate powder in a cylindrical mould, followed by sintering to confer to the pellets the necessary characteristics, such as mechanical resistance and density.