Patent Number: 
Section: claims

1. An assembly for mounting a fuel assembly in a nuclear reactor comprising:a fuel assembly including fuel rods within the fuel assembly, the fuel assembly including a lower tie plate with a fuel assembly mating fixture on a bottom portion of the fuel assembly; anda fuel support including a fuel support mating fixture, the fuel support mating fixture and the fuel assembly mating fixture shaped to fit into one another at only one, only two, or only three orientations of the fuel assembly relative to the fuel support,wherein the fuel assembly mating fixture forming a bottom portion of the fuel assembly is configured to align and mate with the fuel support mating fixture as the fuel assembly is vertically lowered into the fuel support. 2. The assembly of claim 1 wherein the fuel support is configured for elevating the fuel assembly unless the fuel assembly mating fixture is engaged with the fuel support mating fixture at the only one, only two, or only three orientations. 3. The assembly of claim 1 wherein the fuel assembly mating fixture is positioned about a radial from an axis defined by the fuel assembly at one of the only one, only two, or only three orientations of fuel assembly mating fixture relative to the fuel rods within the assembly. 4. The assembly of claim 3 wherein the fuel support mating fixture is configured from a portion of a body of the fuel support defining an aperture for receiving the lower tie plate. 5. The assembly of claim 1 wherein the fuel assembly mating fixture includes an outer shape of the lower tie plate providing the only one, only two, or only three orientations of the fuel assembly and to a lattice contained therein, and wherein the fuel support mating fixture includes an aperture with a corresponding shape defined by the fuel support for receiving the lower tie plate and maintaining the only one, only two, or only three orientations of the fuel assembly to the fuel support upon installation of the fuel assembly onto the fuel support. 6. The assembly of claim 5 wherein the outer shape of the lower tie plate and the corresponding shape of the aperture are selected from the group consisting of a triangle, a quadrilateral, a pentagon, a heptagon, and a star. 7. The assembly of claim 1 wherein the fuel assembly mating fixture includes a male member, and wherein the fuel support mating fixture includes a female member configured to receive and secure the male member to provide the only one, only two, or only three orientations. 8. The assembly of claim 7 wherein the female member includes a beveled cavity for guiding the lower tie plate into the cavity and appropriately mating the fuel assembly mating fixture with the fuel support mating fixture. 9. The assembly of claim 1 wherein the fuel support mating fixture includes a male member, and wherein the fuel assembly mating fixture includes a female member configured to receive and secure the male member to provide the only one, only two, or only three orientations. 10. The assembly of claim 1 wherein the fuel rods within the fuel assembly are arranged to have a predetermined pattern with the only one, only two, or only three orientations within the fuel assembly.