Patent Number: 054467730
Section: claims

1. A heterogeneously loaded fast reactor core comprising a plurality of core fuel assemblies and a plurality of target fuel assemblies, each of said core fuel assemblies comprising a hexagonal wrapper tube and a plurality of core fuel rods positioned within said wrapper tube, each of said core fuel rods having a first predetermined diameter,  each of said target fuel assemblies comprising a hexagonal wrapper tube and a plurality of target fuel rods positioned within said wrapper tube, each of said target fuel rods having a second predetermined diameter, each of said target fuel rods containing 20 to 50% of minor actinide nuclides,  said second predetermined diameter being smaller than said first predetermined diameter,  each of said wrapper tubes of said core fuel assemblies and of said target fuel assemblies, being of the same shape and size,  each of said core fuel assemblies having 271 core fuel rods,  each of said target fuel assemblies having either 331 or 397 target fuel rods,  said fast reactor core having 30 to 50 target fuel assemblies heterogeneously dispersed and loaded therein.  each of said core fuel assemblies comprising a hexagonal wrapper tube and a plurality of core fuel rods positioned within said wrapper tube, each of said core fuel rods having a first predetermined diameter,  each of said target fuel assemblies comprising a hexagonal wrapper tube and a plurality of target fuel rods positioned within said wrapper tube, each of said target fuel rods having a second predetermined diameter, each of said target rods containing aluminum oxide, magnesium oxide, aluminum magnesium oxide, cerium oxide, gadolinium oxide, aluminum nitride or zirconium nitride, to which 20 to 50% of minor actinide nuclides are added.  said second predetermined diameter being smaller than said first predetermined diameter,  each of said wrapper tubes of said core fuel assemblies and of said target fuel assemblies, being of the same shape and size,  each of said core fuel assemblies having 271 core fuel rods,  each of said target fuel assemblies having either 331 or 397 target fuel rods,  said fast reactor core having 30 to 50 target fuel assemblies heterogeneously dispersed and loaded therein. 2. The fast reactor core as claimed in claim 1, wherein the basic material of the fuel containing minor actinide nuclides is a mixed oxide or nitride of uranium and plutonium. 3. A heterogeneously loaded fast reactor core comprising a plurality of core fuel assemblies and a plurality of target fuel assemblies,