Nuclear reactor fuel assemblies and process for production

Patent metadata

Field	Value
Publication number	US-12094618-B2
Application number	US-201916731867-A
Country	US
Kind code	B2
Filing date	Dec 31, 2019
Priority date	Jan 18, 2019
Publication date	Sep 17, 2024
Grant date	Sep 17, 2024

Abstract

A nuclear fuel assembly for a nuclear reactor core including at least one fuel cartridge having a lattice structure including an outer wall defining an interior volume, at least one flow channel extending through the interior volume of the lattice structure, at least one lattice site disposed in the interior of the lattice structure; and at least one fuel compact disposed within a corresponding one of the at least one lattice site. A cross-sectional shape of the at least one fuel compact is the same as a cross-sectional shape of the corresponding one of the at least one lattice site.

First claim

The invention claimed is:

1. A nuclear fuel assembly for a nuclear reactor core, comprising:
at least one fuel cartridge comprising:
a lattice structure including an outer wall defining an interior volume and a plurality of inner walls, the lattice structure defining a longitudinal center axis,
at least one elongated tube extending through the interior volume of the lattice structure to define a flow channel;
the lattice structure defining at least one lattice site disposed in the interior of the lattice structure adjacent to the elongated tube, a horizontal cross-sectional shape of the lattice site being defined at least in part by at least one of the inner walls and a corresponding portion of an outer circumference of the elongated tube; and
at least one fuel compact disposed within a corresponding one of the at least one lattice site, the fuel compact including a fuel compact cladding tube defining an interior volume,
wherein a horizontal cross-sectional shape of the at least one fuel compact is non- circular and is the same as the horizontal cross-sectional shape of the corresponding one of the at least one lattice site.

2. The nuclear fuel assembly of claim 1 , wherein:
the at least one elongated tube of the lattice structure comprises a plurality of elongated tubes defining respective flow channels,
the at least one lattice site of the lattice structure comprises a plurality of lattice sites, and
the at least one fuel compact comprises a plurality of fuel compacts, each fuel compact including:
a plurality of fuel pins, each fuel pin including a pin cladding tube defining an interior volume, and fissionable fuel disposed within the interior volume of the pin cladding tube,
wherein the plurality of fuel pins is disposed within the interior volume of the fuel compact cladding tube, and the horizontal cross-sectional shape of the fuel compact is defined by the fuel compact cladding tube.

3. The nuclear fuel assembly of claim 2 , wherein the fissionable fuel in the plurality of fuel pins is one of a fuel pellet, a plurality of fuel kernels and fuel powder.

4. The nuclear fuel assembly of claim 2 , wherein each fuel pin and the fuel compact cladding tube of each fuel compact are cylindrical prior to a swaging process that results in the horizontal cross-sectional shape of the fuel compact.

5. The nuclear fuel assembly of claim 4 , wherein an outer diameter of a first fuel pin is greater than the outer diameter of a second fuel pin, the first and the second fuel pins being disposed in one of the plurality of fuel compact cladding tubes.

6. The nuclear fuel assembly of claim 2 , wherein the at least one fuel cartridge comprises a plurality of fuel cartridges, and each fuel cartridge further comprises a top wall and a bottom wall disposed on opposite ends of the lattice structure so that each lattice site defines a sealed volume.

7. The nuclear fuel assembly of claim 6 , wherein the top wall and bottom wall of each fuel cartridge defines a plurality of apertures, each aperture corresponding to a location of a corresponding flow channel of the fuel cartridge.

8. The nuclear fuel assembly of claim 2 , each lattice structure further comprising a plurality of inner walls, wherein each inner wall extends between either of a pair of adjacent elongated tubes or an elongated tube and the outer wall of the lattice structure.

9. The nuclear fuel assembly of claim 2 , wherein the outer wall of each lattice structure has a hexagonal cross-section taken horizontally to the longitudinal center axis of the lattice structure.

10. The nuclear fuel assembly of claim 9 , wherein the nuclear fuel assembly includes a plurality of fuel cartridges that are disposed end to end and secured to each other.

11. The nuclear fuel assembly of claim 9 , wherein the fuel cartridges of the fuel assembly are secured to each other by one of diffusion bonding, resistance welding and mechanical fastening.

12. The nuclear fuel assembly of claim 9 , wherein a material gradient of a first fuel cartridge is different than a material gradient of a second fuel cartridge.

13. The nuclear fuel assembly of claim 9 , wherein fuel enrichment of a first fuel cartridge is different than a fuel enrichment of a second fuel cartridge.

14. The nuclear fuel assembly of claim 13 , wherein the first fuel cartridge includes a greater amount of fissionable fuel than does the second fuel cartridge.

15. The nuclear fuel assembly of claim 1 , wherein the horizontal cross-sectional shape of both the at least one fuel compact and the at least one lattice site is a trefoil.

16. A nuclear fuel assembly for a nuclear reactor core, comprising:
at least one fuel cartridge comprising:
a lattice structure including an outer wall defining an interior volume;
at least one flow channel extending through the interior volume of the lattice structure;
at least one lattice site disposed in the interior of the lattice structure; and
at least one fuel compact including a longitudinal center axis, comprising:
a fuel compact cladding tube defining an interior volume, and
a plurality of fuel pins arranged inside the fuel compact cladding in parallel with one another, each fuel pin including a longitudinal center axis, a pin cladding tube defining an interior volume, and fissionable fuel disposed within the interior volume of the pin cladding tube,

wherein the plurality of fuel pins include at least a first fuel pin having an outer diameter that is greater than an outer diameter of a second fuel pin, and the plurality of fuel pins is disposed within the interior volume of the fuel compact cladding tube so that a first distance between the longitudinal center axis of the first fuel compact fuel pin and the longitudinal center axis of the fuel compact is greater than a second distance between the longitudinal center axis of the fuel compact second fuel pin and the longitudinal center axis of the fuel compact.

17. The nuclear fuel assembly of claim 16 , wherein:
the at least one flow channel of the lattice structure comprises a plurality of flow channels,
the at least one lattice site of the lattice structure comprises a plurality of lattice sites, and
the at least one fuel compact comprises a plurality of fuel compacts.

18. The nuclear fuel assembly of claim 16 , wherein a horizontal cross-sectional shape of the at least one fuel compact is non-circular and is the same as a horizontal cross-sectional shape of the corresponding one of the at least one lattice site.

19. The nuclear fuel assembly of claim 18 , wherein the horizontal cross-sectional shape of both the at least one fuel compact and the at least one lattice site is a trefoil.

20. A nuclear fuel assembly for a nuclear reactor core, comprising:
at least one fuel cartridge comprising:
a lattice structure including an outer wall defining an interior volume, the lattice structure defining a longitudinal center axis;
a plurality of elongated tubes extending through the interior volume of the lattice structure to define respective flow channels;
the lattice structure defining a plurality of lattice sites disposed in the interior of the lattice structure; and
a plurality of fuel compacts disposed within corresponding ones of the lattice sites,
wherein a horizontal cross-sectional shape of each of the fuel compacts is non-circular and is the same as a horizontal cross-sectional shape of the corresponding lattice site and wherein a portion of the horizontal cross-sectional shape of the corresponding lattice site is defined

Assignees

• Bwxt Advanced Tech Llc

Inventors

• Shargots Scott J
• Neeley Gary W
• Ziegler Ryan Z

Classifications

• Y10S376/903

  Shapes · CPC title

• G21C5/06

  Means for locating or supporting fuel elements {(means forming part of the element G21C3/12)} · CPC title

• Y02E30/30

  Nuclear fission reactors · CPC title

• G21C3/328 Primary

  Relative disposition of the elements in the bundle lattice · CPC title

• G21D5/02

  Reactor and engine structurally combined, e.g. portable · CPC title