Symmetric blanket nuclear fuel assembly

Claim 2

In a fuel assembly having a plurality of spaced-apart fuel rods, the combination comprising: (a) a first group of said fuel rods containing natural uranium only; and (b) a second group of said fuel rods constituting the remainder thereof containing enriched uranium only; (c) said fuel rods of said first group being surrounded by said fuel rods of said second group in a predetermined symmetrical relationship; (d) said first group of said fuel rods forming an inner, centrally-located, generally squared pattern wherein the only fuel rods present in said inner squared pattern are said fuel rods of said first group; (e) said second group of said fuel rods forming an outer, peripherally-located, generally squared annular pattern which surrounds said first group wherein the only fuel rods present in said outer squared pattern are said fuel rods of said second group.

Claim 3

The fuel assembly as recited in claim 1, wherein said first and second groups of fuel rods together compose a squared array in which said fuel rods of each group are aligned with one another in columns and rows.

Claim 4

The fuel assembly as recited in claim 1, wherein said patterns of said first and second groups of fuel rods together compose a squared array of fuel rods.

Claim 5

The fuel assembly as recited in claim 1, wherein: said squared pattern of said first group has four sides; and said squared annular pattern of said second group surrounds said first group on all four sides thereof.

Claim 6

The fuel assembly as recited in claim 1, further comprising: a plurality of guide thimbles disposed in spaced-apart relationship among both said first and second groups of said fuel rods.

Claim 7

The fuel assembly as recited in claim 5, wherein said guide thimbles are formed in a generally squared pattern of aligned columns and rows of said thimbles.

Claim 8

In a fuel assembly for use in a radial blanket in a nuclear reactor core, said fuel assembly having a plurality of spaced-apart fuel rods, the combination comprising: (a) a first group of said fuel rods containing natural uranium only; (b) a second group of said fuel rods constituting the remainder thereof containing enriched uranium only; (c) said fuel rods of said first group being surrounded by said fuel rods of said second group in a predetermined symmetrical relationship wherein said first and second groups together compose a squared array of fuel rods; (d) said first group of fuel rods in said squared array forming an inner, centrally-located, generally squared pattern wherein the only fuel rods present in said inner squared pattern are said fuel rods of said first group; (e) said second group of fuel rods in said squared array forming an outer, peripherally-located, generally squared annular pattern which surrounds said first group wherein the only fuel rods present in said outer squared pattern are said fuel rods of said second group; (f) said rods of each group being aligned with one another in columns and rows; and (g) a plurality of guide thimbles interspersed in spaced-apart relationship among both said first and second groups of fuel rods in a generally squared pattern; (h) said guide thimbles in said squared pattern thereof being aligned in columns and rows.

Claim 9

In a fuel assembly for use in a radial blanket in a nuclear reactor core, said fuel assembly having a plurality of spaced-apart fuel rods, the combination comprising: (a) a first group of said fuel rods containing natural uranium only; (b) a second group of said fuel rods constituting the remainder thereof containing enriched uranium only; (c) said fuel rods of said first group being surrounded by said fuel rods of said second group in a predetermined symmetrical relationship wherein said first and second groups together compose a squared array of fuel rods; (d) said first group of fuel rods in said squared array forming an inner, centrally-located, generally squared pattern wherein the only fuel rods present in said inner squared pattern are said fuel rods of said first group; (e) said second group of fuel rods in said squared array forming an outer, peripherally-located, generally squared annular pattern which surrounds said first group wherein the only fuel rods present in said outer squared pattern are said fuel rods of said second group; (f) said rods of each group being aligned with one another in columns and rows; and (g) a plurality of guide thimbles interspersed in spaced-apart relationship among both said first and second groups of fuel rods in a generally squared pattern; (h) said guide thimbles in said squared pattern thereof being aligned in columns and rows.