Fast reactor fuel assembly

Fuel elements consisting of sections filled with fissile or raw materials and of collection sections for collecting gaseous fission products are placed in a fast reactor fuel assembly whose one base ends in a head while the other ends in a shank. The collection sections are divided in a central and a peripheral group of which at least one is situated downstream of the coolant, advancing the fuel element material sections. The design described allows reducing pressure to which the jacket walls are rated. Thus, the fuel assembly size in the core can be reduced and the multiplication factor of nuclear fuel increased. (J.B.)