초록 ▼

An open lattice elongated nuclear fuel assembly including small diameter fuel rods disposed in an array spaced a selected distance above an array of larger diameter fuel rods for use in a nuclear reactor having liquid coolant flowing in an upward direction. Plenums are preferably provided in the upp

An open lattice elongated nuclear fuel assembly including small diameter fuel rods disposed in an array spaced a selected distance above an array of larger diameter fuel rods for use in a nuclear reactor having liquid coolant flowing in an upward direction. Plenums are preferably provided in the upper portion of the upper smaller diameter fuel rods and in the lower portion of the lower larger diameter fuel rods. Lattice grid structures provide lateral support for the fuel rods and preferably the lowest grid about the upper rods is directly and rigidly affixed to the highest grid about the lower rods.

대표청구항 ▼

A composite nuclear fuel assembly adapted for use with a thermal nuclear reactor having a liquid coolant flowing upwardly through a core including said assemblies in a vertical orientation, said assembly comprising: a plurality of elongated coextending cylindrical upper nuclear fuel rods having fiss

A composite nuclear fuel assembly adapted for use with a thermal nuclear reactor having a liquid coolant flowing upwardly through a core including said assemblies in a vertical orientation, said assembly comprising: a plurality of elongated coextending cylindrical upper nuclear fuel rods having fissionable nuclear fuel encased in a sealed cladding, said upper rods arranged in a closely spaced array; a plurality of upper lattice structures disposed about said array of upper rods spaced at preselected elevations along said upper rods for laterally supporting said rods in individual cells, each said cell laterally enclosing a corresponding one of said upper rods; a plurality of elongated cylindrical coextending lower nuclear fuel rods having fissionable nuclear fuel encased in a sealed cladding, said lower rods being arranged in a closely spaced array, the top of said lower rods being spaced a preselected distance below the bottom of said upper rods and each being of larger diameter than said upper fuel rods, the number of said lower rods in said assembly being smaller than the number of upper rods in said assembly; and a plurality of lower lattice structures disposed about said array of lower rods spaced at preselected elevations along said lower rods for laterally supporting said lower rods in individual cells, each said cell laterally enclosing a corresponding one of said upper rods the lateral periphery of said lower lattice structures being sized substantially similar to the lateral periphery of said upper lattice structures; said upper and lower rods being the only fuel bearing rods in said assembly.