Disclosed embodiments include fuel assemblies, fuel element, cladding material, methods of making a fuel element, and methods of using same.

Nuclear fuel assemblies include fuel elements that are sintered or cast into billets and co-extruded into a spiral, multi-lobed shape. The fuel kernel may be a metal alloy of metal fuel material and a metal-non-fuel material, or ceramic fuel in a metal non-fuel matrix. The fuel elements may use more highly enriched fissile material while maintaining safe operating temperatures. Such fuel elements according to one or more embodiments may provide more power at a safer, lower temperature than possible with conventional uranium oxide fuel rods. The fuel assembly may also include a plurality of conventional UO.sub.2 fuel rods, which may help the fuel assembly to conform to the space requirements of conventional nuclear reactors.

A zirconium alloy is manufactured through melting; solution heat treatment at 1,000 to 1,050 C. () for 30 to 40 min and -quenching using water; preheating at 630 to 650 C. for 20 to 30 min and hot rolling at a reduction ratio of 60 to 65%; primary intermediate vacuum annealing at 570 to 590 C. for 3 to 4 hr and primarily cold-rolled at a reduction ratio of 30 to 40%; secondary intermediate vacuum annealing at 560 to 580 C. for 2 to 3 hr and secondarily cold-rolled at a reduction ratio of 50 to 60%; tertiary intermediate vacuum annealing at 560 to 580 C. for 2 to 3 hr and tertiarily cold-rolled at a reduction ratio of 30 to 40%; and final vacuum annealing at 460 to 590 C. for 7 to 9 hr.

A zirconium alloy is manufactured through melting; solution heat treatment at 1,000 to 1,050 C. () for 30 to 40 min and -quenching using water; preheating at 630 to 650 C. for 20 to 30 min and hot rolling at a reduction ratio of 60 to 65%; primary intermediate vacuum annealing at 570 to 590 C. for 3 to 4 hr and primarily cold-rolled at a reduction ratio of 30 to 40%; secondary intermediate vacuum annealing at 560 to 580 C. for 2 to 3 hr and secondarily cold-rolled at a reduction ratio of 50 to 60%; tertiary intermediate vacuum annealing at 560 to 580 C. for 2 to 3 hr and tertiarily cold-rolled at a reduction ratio of 30 to 40%; and final vacuum annealing at 460 to 590 C. for 7 to 9 hr.

A fuel assembly for use in a core of a nuclear power reactor. The assembly includes a plurality of helically twisted fuel elements supported by a frame in a fuel rod bundle. Each of the fuel elements includes fissile material. When viewed in a cross-section that is perpendicular to an axial direction of the fuel assembly, the outermost fuel elements of the fuel rod bundle define a substantially circular perimeter. The fuel elements are arranged in a mixed grid pattern that includes a first, rectangular grid pattern and a second, triangular grid pattern.

A fuel assembly for use in a core of a nuclear power reactor. The assembly includes a plurality of helically twisted fuel elements supported by a frame in a fuel rod bundle. Each of the fuel elements includes fissile material. When viewed in a cross-section that is perpendicular to an axial direction of the fuel assembly, the outermost fuel elements of the fuel rod bundle define a substantially circular perimeter. The fuel elements are arranged in a mixed grid pattern that includes a first, rectangular grid pattern and a second, triangular grid pattern.

Disclosed embodiments include fuel assemblies, fuel element, cladding material, methods of making a fuel element, and methods of using same.

Disclosed embodiments include fuel assemblies, fuel element, cladding material, methods of making a fuel element, and methods of using same.

Annular metal fuel and fuel rods are described that have improved performance over uranium oxide fuel rods. The annular metal fuel can be made out of porous metal nuclear fuel and will generate more power and operate at a much lower temperature than uranium oxide fuel. The annular metal fuel rods may be used in traveling wave reactors and other fast reactors. Pressurized water reactors may also be retrofit with annular metal fuel rods to improve reactor performance.

Annular metal fuel and fuel rods are described that have improved performance over uranium oxide fuel rods. The annular metal fuel can be made out of porous metal nuclear fuel and will generate more power and operate at a much lower temperature than uranium oxide fuel. The annular metal fuel rods may be used in traveling wave reactors and other fast reactors. Pressurized water reactors may also be retrofit with annular metal fuel rods to improve reactor performance.