Abstract: A fuel assembly design for nuclear reactors that is used in fast neutron reactor cores to provide more reliable spacing of a fuel element bundle in a fuel assembly and reduced local stress in the cladding of the fuel elements in the region where the elements are in contact with spacing elements. The fuel assembly has a top nozzle and a bottom nozzle which are connected to one another by a jacket. A bundle of rod-type fuel is elements arranged in the fuel assembly with the aid of a grid and spiral spacer elements wrapped around the cladding of each fuel element. At least the peripheral fuel elements in the bundle are provided with spacer elements in the form of thin-walled tubes with longitudinal through slots, wherein the elements have a substantially oval cross section in the regions where they are in contact with the jacket.

Abstract: A fuel assembly design for nuclear reactors that is used in fast neutron reactor cores to provide more reliable spacing of a fuel element bundle in a fuel assembly and reduced local stress in the cladding of the fuel elements in the region where the elements are in contact with spacing elements. The fuel assembly has a top nozzle and a bottom nozzle which are connected to one another by a jacket. A bundle of rod-type fuel is elements arranged in the fuel assembly with the aid of a grid and spiral spacer elements wrapped around the cladding of each fuel element. At least the peripheral fuel elements in the bundle are provided with spacer elements in the form of thin-walled tubes with longitudinal through slots, wherein the elements have a substantially oval cross section in the regions where they are in contact with the jacket.

Abstract: The invention relates to nuclear technology and may be used in preparing fuel rods and fuel assemblies for the cores of fast-neutron reactors utilizing a liquid-metal coolant. The invention reduces metal content of a fuel rod the contact stresses occurring in a fuel rod casing in a reactor core during nuclear fuel burnup. The fast neutron reactor fuel rod includes nuclear fuel disposed in a hermetically-sealed container in the form of a thin-walled tubular casing, and a spacing element wound in a wide-pitch spiral and secured to the casing or to the end components. The spacing element is a thin-walled tube having a longitudinal through-slot along the length thereof. Alternatively, the spacing element is made of a thin-walled tube or a thin band having a middle portion in the form of a tube with a longitudinal through-slot of a set width, and end components of fragments of the cylindrical casing.