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US 10,438,704 B2Granted
Nuclear fuel assembly support feature
AssigneeWestinghouse Electric Corp.
InventorsNathan J. Payne, Jeffrey M. McCarty
Life of this patent
Estimating the term…
Abstract
A nuclear fuel assembly having lateral support provided by a bimetallic spring that extends from a side of the fuel assembly under certain core conditions to pressure against an adjacent component and withdraws under other core conditions, such as shutdown, to enable the nuclear fuel assembly to be aligned or withdrawn from the core and repositioned.
Claims14
A nuclear fuel assembly having an elongated dimension and comprising:
- a plurality of interconnected components wherein at least some of the interconnected components comprise:
- a top nozzle;
- a bottom nozzle;
- a plurality of guide thimbles extending between the top nozzle and the bottom nozzle;
- a plurality of fuel rods extending between the top nozzle and the bottom nozzle;
- and
- a plurality of grids arranged in a tandem spaced relationship that extends between the top nozzle and the bottom nozzle along the elongated dimension, with each of the grids having a plurality of cells some of which support the fuel rods and others through which the guide thimbles respectively pass and attach to the plurality of grids;
- wherein at least some of the interconnected components have a peripheral surface area that extends in a plane a distance along the elongated dimension;
- wherein one of the at least some of the interconnected components has a bimetallic spring that moves between a first and second position relative to the plane as the fuel assembly transitions from a reactor core shutdown temperature to a reactor core operating temperature, with one of the first and second positions placing the bimetallic spring in contact with an adjoining component when the nuclear fuel assembly is placed in a reactor core;
- wherein the bimetallic spring comprises a base material coated with a material having a different coefficient of thermal expansion than the base material,
- wherein the bimetallic spring is configured in a round disc shape,
- wherein the bimetallic spring is provided proximate one corner of the one of the at least some of the interconnected components, and
- wherein a tip of the disc shape fits in a recess in a side of the adjoining component.
10 more elements
A nuclear fuel assembly having an elongated dimension and comprising:
- a plurality of interconnected components wherein at least some of the interconnected components comprise:
- a top nozzle;
- a bottom nozzle;
- a plurality of guide thimbles extending between the top nozzle and the bottom nozzle;
- a plurality of fuel rods extending between the top nozzle and the bottom nozzle;
- and
- a plurality of grids arranged in a tandem spaced relationship that extends between the top nozzle and the bottom nozzle along the elongated dimension, with each of the grids having a plurality of cells some of which support the fuel rods and others through which the guide thimbles respectively pass and attach to the plurality of grids;
- wherein at least some of the interconnected components have a peripheral surface area that extends in a plane a distance along the elongated dimension;
- wherein one of the at least some of the interconnected components has a bimetallic spring that moves between a first and second position relative to the plane as the fuel assembly transitions from a reactor core shutdown temperature to a reactor core operating temperature, with one of the first and second positions placing the bimetallic spring in contact with an adjoining component when the nuclear fuel assembly is placed in a reactor core;
- wherein the bimetallic spring comprises a base material coated with a material having a different coefficient of thermal expansion than the base material,
- wherein the bimetallic spring is configured in a round disc shape, and wherein the bimetallic spring is supported on at least the top nozzle.
8 more elements
A nuclear reactor having a reactive core comprising a plurality of fuel assemblies, each having an elongated dimension and comprising:
- a plurality of interconnected components wherein at least some of the interconnected components comprise:
- a top nozzle;
- a bottom nozzle;
- a plurality of guide thimbles extending between the top nozzle and the bottom nozzle;
- a plurality of fuel rods extending between the top nozzle and the bottom nozzle;
- and
- a plurality of grids arranged in a tandem spaced relationship that extends between the top nozzle and the bottom nozzle along the elongated dimension, with each of the grids having a plurality of cells some of which support the fuel rods and others through which the guide thimbles respectively pass and attach to the grid;
- wherein at least some of the interconnected components have a peripheral surface area that extends in a plane a distance along the elongated dimension;
- wherein on some of the fuel assemblies one of the at least some of the interconnected components has a bimetallic spring that moves between a first and second position relative to the plane as the fuel assembly transitions from a reactor core shutdown temperature to a reactor core operating temperature, with one of the first and second positions placing the bimetallic spring in contact with an adjoining component of the reactive core;
- wherein the bimetallic spring comprises a base material coated with a material having a different coefficient of thermal expansion than the base material,
- wherein the bimetallic spring is configured in a round disc shape, and
- wherein the bimetallic spring is supported on at least the top nozzle.
9 more elements
Dependencies are inferred from the claim text.