A method for coating of uo.sub.2 - core - fuel particles with al.sub.2 o.sub.3 and manufactured according to this process a nuclear reactor fuel element -

摘要

Particles of uranium dioxide are coated with a first porous layer of alumina and a second outer layer of impermeable alpha alumina by hydrolysing aluminium chloride at 200-900 DEG C. to form the porous layer and then at 900-1400 DEG C. to form the impermeable layer, in the presence of hydrogen in a fluidized bed of the uranium dioxide particles. The uranium dioxide preferably has a particle size of 50-400 m . The example refers to the first layer being formed at 750 DEG C. for 6 hours and the second layer at 1000 DEG C. for 12 hours.