Container and system for handling damaged nuclear fuel, and method of making the same

Patent metadata

Field	Value
Publication number	US-9748009-B2
Application number	US-201214239752-A
Country	US
Kind code	B2
Filing date	Aug 20, 2012
Priority date	Aug 19, 2011
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

A container and system for handling damaged nuclear fuel, and a method of making the same. In one embodiment, the invention is a damaged fuel container having a specially designed top cap that can be detachably coupled to the elongated tubular wall by simply translating the top cap into proper position within, the elongated tubular wall, wherein biased locking elements automatically lock the top cap to the elongated tubular wall. In another embodiment, the vent screens of the damaged fuel container are integrally formed rather than being separate components. In still other embodiments, the lower vent screens are arranged on an upstanding portion of the damaged fuel container. In an even further embodiment, the elongated tubular wall is formed by an extrusion process.

First claim

What is claimed is:

1. A system for storing and/or transporting nuclear fuel comprising:
a vessel comprising a vessel cavity and extending along a vessel axis;
a fuel basket positioned within the vessel cavity, the fuel basket comprising a grid forming a plurality of elongated cells, each of the cells extending along a cell axis that is substantially parallel to the vessel axis; and
an elongated tubular container comprising a container cavity containing damaged nuclear fuel, the elongated tubular container positioned within one of the cells, the elongated tubular container further comprising:
an extruded tubular wall forming a container cavity about a container axis, the extruded tubular wall formed of a metal matrix composite having neutron absorbing particulate reinforcement;
a bottom cap coupled to a bottom end of the extruded tubular wall, the bottom cap comprising a body including a floor plate and plurality of oblique walls arranged obliquely to the container axis, the oblique walls extending upward from a perimeter of the floor plate to define an annular wall structure forming a tapered bottom end of the container;
a top cap detachably coupled to a top end of the extruded tubular wall;
each oblique wall including a first screen comprising a plurality of openings that define lower vent passageways into a bottom of the container cavity; and
a second screen comprising a plurality of openings that define upper vent passageways into a top of the container cavity.

2. The system according to claim 1 wherein a top portion of the extruded tubular wall comprises locking apertures, and the top cap comprises locking elements that are alterable between a retracted state and an extended state, the locking elements biased into the extended state, and wherein the top cap is detachably coupled to the extruded tubular wall when the locking elements are in the extended state and protrude into the locking apertures.

3. The system according to claim 2 wherein contact between the extruded tubular wall and the locking elements forces the locking elements into the retracted state during insertion of the top cap into the container cavity until the locking elements become aligned with the locking apertures.

4. The system according to claim 1 wherein the bottom cap comprises the first screen and the top cap comprises the second screen.

5. The system according to claim 1 further comprising a floor of the container cavity, and wherein at least one of the plurality of openings of the first screen is located an axial distance above the floor of the container cavity.

6. The system according to claim 1 , wherein the vessel further comprises a cylindrical vessel shell and a vessel floor plate having a solid structure free of openings, the vessel floor plate seal welded to the vessel shell for hermetically sealing the vessel cavity.

7. The system according to claim 6 , wherein the floor plate of the bottom cap of the container abuttingly contacts the vessel floor plate when the container is positioned in the one of the cells.

8. The system according to claim 7 , wherein the floor plate of the bottom cap has a solid structure free of openings.

9. The system according to claim 1 , wherein the floor plate of the bottom cap has a solid structure free of openings.

10. A system for storing and/or transporting nuclear fuel comprising:
a vessel comprising a vessel cavity and extending along a vessel axis;
a fuel basket positioned within the vessel cavity, the fuel basket comprising a grid forming a plurality of elongated cells, each of the cells extending along a cell axis that is substantially parallel to the vessel axis; and
an elongated tubular container comprising a container cavity containing damaged nuclear fuel, the elongated tubular container positioned within one of the cells, the elongated tubular container further comprising:
an extruded tubular wall forming a container cavity about a container axis, the extruded tubular wall formed of a metal matrix composite having neutron absorbing particulate reinforcement;
a bottom cap fixedly coupled to a bottom end of the extruded tubular wall;
a top cap detachably coupled to a top end of the extruded tubular wall;
the bottom cap including a plurality of first screens each comprising a plurality of openings that define lower vent passageways in fluid communication with a bottom of the container cavity; and
the top cap including a second screen comprising a plurality of openings that define upper vent passageways in fluid communication with a top of the container cavity;

wherein a top portion of the extruded tubular wall comprises locking apertures, and the top cap comprises locking elements in the form of laterally and linearly movable pins each arranged for insertion into a corresponding one of the locking apertures when the top cap is coupled to the extruded tubular wall;
each of the pins being laterally movably alterable between a laterally inward retracted state and a laterally outward extended state, the locking elements biased outward into the extended state via a spring, and wherein the top cap is detachably locked to the extruded tubular wall when the pins are in the extended state and protrude into the locking apertures.

11. The system according to claim 10 , wherein contact between the extruded tubular wall and the pins forces the pins into the retracted state when engaged by the extruded tubular wall during insertion of the top cap into the container cavity until the pins each become aligned with one of the locking apertures and move to the extended state engaged with the apertures.

12. The system according to claim 11 , wherein the locking apertures are disposed in an upper section of the extruded tubular wall having a configuration that flares outward moving from a transition shoulder upwards to a top edge of the extruded tubular wall, the pins engaging the upper section and forced into the retracted state when the top cap is inserted into the container cavity.

13. The system according to claim 10 , wherein the bottom cap comprises a body including a floor plate and plurality of oblique walls arranged obliquely to the container axis, the oblique walls extending upward from a perimeter of the floor plate to define an annular wall structure forming a tapered bottom end of the container.

14. A system for storing and/or transporting nuclear fuel comprising:
a vessel comprising a vessel cavity and extending along a vessel axis;
a fuel basket positioned within the vessel cavity, the fuel basket comprising a grid forming a plurality of elongated cells, each of the cells extending along a cell axis that is substantially parallel to the vessel axis; and
an elongated tubular container comprising a container cavity containing damaged nuclear fuel, the elongated tubular container positioned within one of the cells, the elongated tubular container further comprising:
an extruded tubular wall forming a container cavity about a container axis, the extruded tubular wall formed of a metal matrix composite having neutron absorbing particulate reinforcement;
a bottom cap fixedly coupled to a bottom end of the extruded tubular wall;
a top cap detachably coupled to a top end of the extruded tubular wall;
the bottom cap including a plurality of first screens each comprising a plurality of openings that define lower vent passageways in fluid communication with a bottom of the container cavity; and
the top cap including a second screen comprising a plurality of openings that define upper vent passageways in fluid communication with a top of the container cavity;

wherein a top portion of the extruded tub

Assignees

• Singh Krishna P
• Holtec International

Inventors

• Singh Krishna P

Classifications

• G21F5/008 Primary

  Containers for fuel elements · CPC title

• G21C19/26

  Arrangements for removing jammed or damaged fuel elements or control elements; Arrangements for moving broken parts thereof · CPC title

• B23K2103/172

  wherein at least one of the layers is non-metallic · CPC title

• G21F5/012

  Fuel element racks in the containers · CPC title

• B23K2101/12

  Vessels · CPC title