Nuclear materials apparatus and implementing the same

Patent metadata

Field	Value
Publication number	US-2021057118-A1
Application number	US-202017080966-A
Country	US
Kind code	A1
Filing date	Oct 27, 2020
Priority date	May 4, 2015
Publication date	Feb 25, 2021
Grant date	—

Abstract

An apparatus for supporting spent nuclear fuel including a plurality of wall plates arranged in an intersecting manner to define a basket apparatus extending along a longitudinal axis. The basket apparatus may include a plurality of fuel cells and a plurality of flux traps between adjacent fuel cells. A plurality of reinforcement members may be positioned in the flux traps and may extend between opposing ones of the wall plates that form the flux traps. Each of the wall plates may be a slotted wall plate. The slotted wall plates may be interlocked with one another to form the basket apparatus. Each of the slotted wall plates may include an upper edge, a lower edge, and a plurality of plate slots formed in each of the upper and lower edges. The plate slots of the slotted wall plates may receive intersecting slotted wall plates.

First claim

What is claimed is:

1 . An apparatus for supporting spent nuclear fuel, the apparatus comprising:
a plurality of wall plates arranged in an intersecting manner to define a basket apparatus extending along a longitudinal axis, the basket apparatus comprising a plurality of fuel cells and a plurality of flux traps between adjacent ones of the fuel cells; and a plurality of reinforcement members positioned in the flux traps and extending between opposing ones of the wall plates that form the flux traps; wherein each of the wall plates is a slotted wall plate, the slotted wall plates interlocked with one another to form the basket apparatus; wherein each of the slotted wall plates comprises an upper edge, a lower edge, and a plurality of plate slots formed in each of the upper and lower edges, the plate slots of each of the slotted wall plates receiving intersecting ones of the slotted wall plates; wherein each of the slotted wall plates further comprises a plurality of reinforcement slots in at least one of the upper edge or the lower edge, the reinforcement slots of the slotted wall plates receiving flange portions of the reinforcement members.

2 . The apparatus according to claim 1 wherein for each of the slotted wall plates, the plate slots have a first height and the reinforcement slots have a second height, the second height being less than the first height.

3 . The apparatus according to claim 1 wherein each of the reinforcement members comprise a body portion and first and second flange portions protruding from opposite sides of the body portion; and wherein for each of the reinforcement members: (1) the first and second flange portions nest within the reinforcement slots of the opposing ones of the slotted wall plates between which the reinforcement member extends; and (2) the body portion abuts outer surfaces of the opposing ones of the slotted wall plates between which the reinforcement member extends, thereby maintaining a fixed distance between the opposing ones of the slotted wall plates between which the reinforcement member extends.

4 . The apparatus according to claim 1 wherein for each of the slotted wall plates, the plates slots and the reinforcement slots are arranged in a pattern comprising a repeating sequence of:
reinforcement slot>plate slot>plate slot.

5 . The apparatus according to claim 1 wherein each of the fuel cells comprises a fuel cell axis that is substantially parallel to the longitudinal axis of the basket apparatus; and wherein for each adjacent pair of the fuels cells, a longitudinal reference plane that extends between and includes the fuel axes of the pair of the fuels cells intersects at least one of the reinforcement members.

6 . The apparatus according to claim 1 wherein the reinforcement members comprises a first set of the reinforcement members and a second set of the reinforcement members; and wherein the first set of the reinforcement members are located adjacent a top end of the basket apparatus and the second set of the reinforcement members are located adjacent a bottom end of the basket apparatus.

7 . A ventilated cask for transporting and/or storing radioactive materials comprising:
a vertically elongated overpack body comprising a longitudinal axis, an outer shell defining an outer surface, an inner shell defining an inner surface, a gap extending radially between the inner and outer shells, and an internal cavity configured for holding a nuclear fuel canister; a base enclosing a bottom end of the cavity; a lid enclosing a top end of the cavity; a plurality of outlet ducts each forming an air outlet passageway from a top portion of the cavity to an external atmosphere; a plurality of arcuately curved air inlet ducts extending radially between the outer and inner surfaces at a bottom portion of the overpack body, the air inlet ducts configured for admitting ambient cooling air into a lower portion of the cavity; the air inlet ducts spaced circumferentially apart around the longitudinal axis and the bottom portion of the overpack body in a symmetric arrangement; a plurality of wall segments comprising a radiation shielding material filled in the gap between each pair of air inlet ducts, each wall segment comprising a circumferentially projecting convex portion and an opposing circumferentially recessed concave portion.

8 . The ventilated cask according to claim 7 , wherein each of the wall segments has a convex outer wall that adjoins the outer shell of the overpack body and a concave inner wall that adjoins the inner shell of the overpack body.

9 . The ventilated cask according to claim 8 , wherein each of the curved segments is a singular uninterrupted monolithic structure.

10 . The ventilated cask according to claim 9 , wherein each wall segment is separated from every other wall segment by the air inlet ducts.

11 . The ventilated cask according to claim 8 , wherein the wall segments are arranged in an intermeshing configuration such that the convex portion of each wall segment is at least partially nested within the concave portion of an adjacent wall segment.

12 . The ventilated cask according to claim 11 , wherein each air inlet duct is interspersed between the convex and concave portions of adjacent wall segments.

13 . A separable multi-component cask for spent nuclear fuel transport and storage comprising:
a vertical longitudinal axis; a vertically elongated first cylinder having a neutron radiation shielding composition, the first cylinder defining a first cavity extending along the longitudinal axis; a vertically elongated second cylinder having a gamma radiation blocking composition, the second cylinder defining a second cavity extending along the longitudinal axis and configured to hold a spent nuclear fuel canister; the second cylinder detachably mounted inside the first cavity of the first cylinder; and an air ventilation annulus formed between the first and second cylinders, the air ventilation annulus defining a heat removal passage to remove heat emitted by the canister when placed inside the second cylinder.

14 . The cask according to claim 13 , wherein the second cylinder has a higher thermal conductivity than the first second cylinder has a higher thermal conductivity than the first shell.

15 . The cask according to claim 13 , wherein the second cylinder includes a bottom lid attached to a bottom end of the second cylinder, and a radially protruding top mounting flange extending circumferentially around a top end of the second cylinder.

16 . The cask according to claim 15 , wherein the top mounting flange is received at least partially with an upwardly open annular recess formed in a top end of the first cylinder.

17 . The cask according to claim 16 , wherein the annular recess is formed by an angle ring having an L-shaped cross section.

18 . The cask according to claim 16 , wherein the annular recess comprises a plurality of raised spacer blocks, the top mounting flange of the second cylinder being seated on the spacer blocks to form a plurality of upper air outlet openings between the top flange and the first cylinder within the recess which is in fluid communication with the air ventilation annulus between the first and second cylinders.

19 . The cask according to claim 18 , wherein the top mounting flange is coupled directly to the spacer blocks by threaded fasteners.

20 . The cask according to claim 15 , wherein the first cylinder includes a castellated top end, the top mounting flange of the

Assignees

• Holtec International

Inventors

• Singh Krishna P
• Anton P Stefan
• Springman Richard M
• Mahorter Robert

Classifications

• Y02E30/30

  Nuclear fission reactors · CPC title

• G21F5/012 Primary

  Fuel element racks in the containers · CPC title

• G21F5/14

  Devices for handling containers or shipping-casks, e.g. transporting devices {loading and unloading, filling of containers (cranes, load-engaging elements or devices for cranes, capstans, winches or tackles B66C)} · CPC title

• G21F5/08

  Shock-absorbers, e.g. impact buffers for containers · CPC title

• G21F5/10

  Heat-removal systems, e.g. using circulating fluid or cooling fins · CPC title