High-density subterranean storage system for nuclear fuel and radioactive waste

Patent metadata

Field	Value
Publication number	US-11469008-B2
Application number	US-202117200333-A
Country	US
Kind code	B2
Filing date	Mar 12, 2021
Priority date	Jan 10, 2013
Publication date	Oct 11, 2022
Grant date	Oct 11, 2022

Abstract

An underground ventilated system for storing nuclear waste materials. The system includes a storage module having an outer shell defining an internal cavity and an inner shell. A majority of the height of the outer shell may be disposed below grade. The outer shell may include a hermetically sealed bottom. First and second canisters are positioned in lower and upper portions within the cavity respectively in vertically stacked relationship. A centering and spacing ring assembly is interspersed between the first and second canisters to transfer the weight of the upper second canister to the lower first canister. The assembly may include centering lugs which laterally restrain the first and second canisters in case of a seismic event. A natural convection driven ventilated air system cools the canisters to remove residual decay heat to the atmosphere. In one non-limiting embodiment, the shells are made of steel.

First claim

What is claimed is:

1. A method for storing nuclear waste canisters comprising:
providing a module comprising a vertically elongated shell defining an internal cavity;
inserting a first canister into the cavity;
inserting a middle ring-lug assembly into the cavity;
positioning the middle ring-lug assembly on top of the first canister;
inserting a second canister into the cavity;
positioning the second canister on the middle ring-lug assembly; and
centering the second canister on the middle ring-lug assembly by engaging a plurality of vertically elongated centering lugs on the middle ring-lug assembly with the second canister.

2. The method according to claim 1 , wherein the step of inserting the first canister is preceded by steps of inserting a bottom ring-lug assembly into the cavity, and the step of inserting the first canister comprises positioning the first canister on the bottom ring-lug assembly.

3. The method according to claim 2 , wherein the step of inserting the bottom ring-lug assembly comprises positioning the bottom ring-lug assembly on a bottom plate of the shell.

4. The method according to claim 2 , wherein the step of inserting the first canister further comprises engaging a bottom of the first canister with a castellated surface of the bottom ring-lug assembly.

5. The method according to claim 4 , wherein the step of inserting the first canister further comprises engaging the canister with a plurality of upwardly protruding centering lugs of the bottom ring-lug assembly.

6. The method according to claim 5 , wherein the centering lugs have a polygonal shape.

7. The method according to claim 5 , wherein the centering lugs of the bottom ring-lug assembly are attached to arcuate raised segments thereof formed by the castellated surface.

8. The method according to claim 5 , wherein the first canister first slideably engages angled edges of the centering lugs when the first canister is positioned on the bottom ring-lug assembly.

9. The method according to claim 1 , wherein the second canister first slideably engages first angled edges of the vertically elongated centering lugs when the second canister is positioned on the middle ring-lug assembly.

10. The method according to claim 1 , further comprising centering the middle ring-lug assembly on the first canister by engaging the plurality of vertically elongated centering lugs on the middle ring-lug assembly with the first canister.

11. The method according to claim 10 , wherein the first canister slideably first engages second angled edges of the vertically elongated centering lugs when the middle ring-lug assembly is centered on first canister.

12. The method according to claim 1 , wherein the vertically elongated centering lugs are attached to an annular body of the middle ring-lug assembly.

13. The method according to claim 1 , wherein the step of positioning the second canister further comprises engaging a castellated surface on the middle ring-lug assembly with the second canister.

14. The method according to claim 13 , wherein the middle ring-lug assembly comprises a laterally widened annular body and the castellated surface is formed by alternating arcuate raised segments and arcuate recessed segments.

15. The method according to claim 1 , wherein the step of positioning the middle ring-lug assembly on top of the first canister further comprises engaging a castellated surface on a bottom of the middle ring-lug assembly with the first canister.

16. A method for storing nuclear waste canisters comprising:
providing a module comprising a vertically elongated shell defining an internal cavity;
inserting a first canister into the cavity;
inserting a middle ring-lug assembly into the cavity;
positioning the middle ring-lug assembly on top of the first canister;
inserting a second canister into the cavity; and
positioning the second canister on the middle ring-lug assembly;
wherein the step of positioning the second canister on the middle ring-lug assembly comprising forming a plurality of radially extending cooling ventilation air openings between the first and second canisters to enhance cooling the canisters.

17. The method according to claim 16 , wherein the ventilation air openings are defined by a castellated surface of the middle ring-lug assembly which engages a bottom surface of the second canister.

18. The method according to claim 1 , further comprising:
positioning a top ring-lug assembly on a top of the second canister;
engaging a plurality of vertically elongated centering lugs with sides of the second canister; and
engaging a castellated bottom surface of the top ring-lug assembly with a top of the second canister.

19. A method for storing nuclear waste canisters comprising:
providing a module comprising a vertically elongated shell defining an internal cavity;
positioning a middle ring-lug assembly on top of a first canister, the middle ring-lug assembly comprising an annular body and a plurality of vertically elongated centering lugs attached to the annular body and protruding radially outwards therefrom;
inserting the combination of the first canister and middle ring-lug assembly into the cavity;
inserting a second canister into the cavity; and

positioning the second canister on the middle ring-lug assembly.

Assignees

• Holtec International

Inventors

• Singh Krishna P

Classifications

• G21F7/015

  Room atmosphere, temperature or pressure control devices · CPC title

• G21F5/14 Primary

  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

• B65D43/02

  Removable lids or covers (with means for piercing, cutting, or tearing a frangible inner closure B65D51/22) · CPC title

• B65D21/0224

  Auxiliary removable stacking elements other than covers · CPC title

• B09B1/006

  Shafts or wells in waste dumps · CPC title