Systems And Methods For Dry Storage And/Or Transport Of Consolidated Nuclear Spent Fuel Rods

• US 20140039235A1
• Filed: 08/02/2013
• Published: 02/06/2014
• Est. Priority Date: 08/02/2012
• Status: Active Grant

• Current Assignee: NAC International Inc. (Hitachi Zosen Corporation)
• Original Assignee: NAC International Inc. (Hitachi Zosen Corporation)
• Inventors: Subiry, Juan C.
• Granted Patent: US 9,558,857 B2
• Time in Patent Office: Days
• US Class Current: 588/16
• CPC Class Codes: G21F 5/012 Fuel element racks in the containers
• CPC Class Codes: G21F 5/10 Heat-removal systems, e.g. using circulating fluid or cooling fins

Abstract

In one embodiment, a system and method for dry storage comprises removing spent fuel rods from their fuel rod assemblies and placing the freed fuel rods in a storage cell of a dry storage canister with a high packing density and without a neutron absorber material present.

Claims

1. A system for dry storing spent fuel rods, the system comprising:

a dry storage canister including an outer housing and an internal basket provided within the housing, the internal basket forming multiple discrete storage cells adapted to receive free fuel rods that have been separated from their fuel rod assemblies.

2. The system of claim 1, wherein the outer housing is an elongated cylindrical housing.

3. The system of claim 1, wherein the storage cells are configured such that a rod packing density of approximately 4 to 6 spent fuel rods per square inch can be achieved.

4. The system of claim 1, wherein the internal basket is made of a metal material having a high thermal conductivity.

5. The system of claim 1, wherein the internal basket is made of one or more of carbon steel, aluminum, or copper.

6. The system of claim 1, wherein the internal basket comprises multiple divider walls that define the storage cells, the divider walls extending radially outward from a center of the canister to the outer housing.

7. The system of claim 6, wherein the divider walls provide a generally triangular, pie-piece configuration to the storage cells.

8. The system of claim 6, wherein the internal basket further comprises a central tube from which the divider walls radially extend.

9. The system of claim 6, wherein the internal basket further comprises end walls that extend between distal ends of the divider walls.

10. The system of claim 1, wherein the storage cells comprise corrugated dividers that separate the fuel rods into multiple discrete rows of rods.

11. The system of claim 1, wherein the internal basket comprises multiple tubes that define the storage cells.

12. The system of claim 11, wherein the tubes are cylindrical tubes.

13. The system of claim 11, wherein the tubes are rectangular.

14. The system of claim 11, wherein the internal basket further comprises a spacer disk that extends between the tubes.

15. The system of claim 1, further comprising a cask in which the canister can be placed.

16. A method for dry storing spent fuel rods, the method comprising:

removing spent fuel rods from their fuel rod assemblies;

placing the fuel rods in a storage cell of a dry storage canister with a high packing density; and

sealing the canister with the rods in a dry state;

wherein the canister contains no neutron absorber material.

17. The method of claim 16, wherein placing the fuel rods in a storage cell comprises placing the fuel rods in the cell with a packing density of approximately 4 to 6 spent fuel rods per square inch.

18. The method of claim 16, wherein placing the fuel rods in a storage cell comprises placing the fuel rods in a cell having a generally triangular, pie-piece configuration in which fewer fuel rods are provided near a center of the canister relative to near outer walls of the canister.

19. The method of claim 18, further comprising dissipating heat from the center of the canister with divider walls that define the storage cell and that extend radially outward from the center of the canister.

20. The method of claim 16, further comprising dissipating heat from the fuel rods using corrugated dividers provided within the storage cell.

21. The method of claim 16, wherein placing the fuel rods in a storage cell comprises placing the fuel rods in a tube that extends along a length direction of the canister.