Fuel subassembly for nuclear reactor

Claim 2

In a nuclear reactor according to claim 2 wherein said strips are interposed between said wrapper tube and said core bundle assembly, and wherein said strips are substantially parallel with the longitudinal axis of said wrapper tube.

Claim 3

In a nuclear reactor according to claim 2 wherein said strips are elongated and wherein said strips are thin and narrow.

Claim 4

In a nuclear reactor, the combination comprising a fuel subassembly including a wrapper tube, an upper core bundle assembly and a lower core bundle assembly contained within said wrapper tube, a first plurality of elongated metal strips, alternate strips having a high coefficient of thermal expansion and a low coefficient of thermal expansion, the strips being alternately connected at their top ends and a their bottom ends in series, one end of said plurality of strips being attached to said wrapper tube and the other end thereof being attached to said core bundle assembly to cause magnified axial displacement of said upper core bundle assembly in an upward direction; a second plurality of elongated metal strips, alternate strips of said second plurality of strips having a high coefficient of thermal expansion and a low coefficient of thermal expansion, said second plurality of strips being alternately connected at their top ends and at their bottom ends in series, one end of said second plurality of strips being attached to said wrapper tube and the other end thereof being attached to said lower bundle to cause axial displacement of said lower bundle assembly in a downward direction, thereby to reduce reactivity of said nuclear reactor when the temperature of said fuel subassembly increases.

Claim 5

In an nuclear reactor to claim 1 wherein said plurality of high coefficient of thermal expansion members and said plurality of low coefficient of thermal expansion members are a plurality of concentric hollow cylinders having a high coefficient of thermal expansion and a plurality of concentric hollow cylinders having a low coefficient of thermal expansion.

Claim 6

In a nuclear reactor according to claim 3 wherein said cylinders are elongated and are disposed between said core bundle assembly and the wrapper tube.

Claim 7

In a nuclear reactor according to claim 3 further comprising a connecting bar disposed in parallel relationship with respect to said cylinders and being positioned within the innermost cylinder, said innermost cylinder being attached to said connecting bar, at least one tie rod fixedly connecting said connecting bar to the wrapper tube, and at least one connecting arm fixedly connecting the outermost cylinder to the core bundle assembly.

Claim 8

In a nuclear reactor according to claim 8 wherein said connecting bar is longer in length than the length of said cylinders, and wherein one tie rod is disposed adjacent one end of the connecting bar anD another tie rod is disposed adjacent the other end of the connecting bar.