Small nuclear reactor containment system

• US 10,460,844 B2
• Filed: 05/09/2017
• Issued: 10/29/2019
• Est. Priority Date: 05/09/2017
• Status: Active Grant

• Current Assignee: Westinghouse Electric Company LLC (Brookfield Asset Management Incorporated)
• Original Assignee: Westinghouse Electric Company LLC (Brookfield Asset Management Incorporated)
• Inventors: Arafat, Yasir, Van Wyk, Jurie
• Primary Examiner(s): Davis, Sharon M
• Application Number:
  US15/590,469
• Publication Number:
  US 20180330836A1
• Time in Patent Office: 903 Days
• Field of Search: 376273, 376274, 376275, 376276
• CPC Class Codes: G21C 13/02 Details
• CPC Class Codes: G21C 15/12 from pressure vessel; from containment vessel
• CPC Class Codes: G21C 15/18 Emergency cooling arrangements; Removing shut-down heat
• CPC Class Codes: G21D 3/06 responsive to faults within the plant in the reactor G21C9/00
• CPC Class Codes: G21F 5/008 Containers for fuel elements
• CPC Class Codes: G21F 5/10 Heat-removal systems, e.g. using circulating fluid or cooling fins
• CPC Class Codes: Y02E 30/00 Energy generation of nuclear origin
• CPC Class Codes: Y02E 30/30 Nuclear fission reactors

Abstract

A nuclear reactor containment system including a nuclear reactor and a container enclosing the nuclear reactor. The container includes a number of heat removal systems each having an active state and an inactive state, wherein the heat removal systems dissipate heat from the container more efficiently in the active state than in the inactive state, and wherein the heat removal systems are structured to switch from the inactive state to the active state based on a temperature of the container.

Claims

1. A nuclear reactor containment system comprising:

a nuclear reactor;

a container enclosing the nuclear reactor, the container including;

at least one heat removal system having an active state and an inactive state, wherein the at least one heat removal system dissipates heat from the container more efficiently in the active state than in the inactive state, and wherein the at least one heat removal system is structured to switch from the inactive state to the active state based on a temperature of the container,

wherein the at least one heat removal system includes a first heat removal system including;

fins disposed in an outer portion of the container and forming a plurality of cooling channels; and

a plurality of air regulating mechanisms structured to block air from flowing through the cooling channels when the first heat removal system is in the inactive state and to allow air to flow through the cooling channels when the first heat removal system is in the active state,

wherein at least one of the air regulating mechanisms includes;

a first plate structured to be disposed over a first cooling channel of the plurality of cooling channels to block airflow through the first cooling channel;

a pivot structured to support a first side of the first plate;

an electromagnetic element structured to support a second side of the first plate via an electromagnetic force and being structured to support the second side of the first plate via the electromagnetic force at a predetermined temperature,

wherein when the first heat removal system is in the inactive state, the electromagnetic element supports the second side of the first plate and the first plate blocks airflow through the first cooling channel, and

wherein when the first heat removal system is in the active state, the electromagnetic element melts and allows the second side of the plate to fall into the first cooling channel and allow airflow through the first cooling channel.

2. The nuclear reactor containment system of claim 1, wherein the at least one heat removal system is structured to switch from the inactive state to the active state at one or more predetermined temperatures of the container above temperatures of the container corresponding to normal operation of the nuclear reactor.

3. The nuclear reactor containment system of claim 1, wherein at least one of the air regulating mechanisms includes:

a bimetallic strip disposed in a second cooling channel of the plurality of cooling channels, the bimetallic strip being structured to bend based on temperature,

wherein the bimetallic strip is structured to be bent in a direction to block airflow in the second cooling channel when the first heat removal system is in the inactive state and to be bent in a direction to allow airflow through the second cooling channel when the first heat removal system is in the active state.

4. The nuclear reactor containment system of claim 1, wherein at least one of the air regulating mechanisms includes:

a second plate structured to be disposed over a second cooling channel of the plurality of cooling channels to block airflow through the second cooling channel;

a pivot structured to support a first side of the second plate;

a fusible element structured to support a second side of the second plate and being structured to melt at a predetermined temperature,

wherein when the first heat removal system is in the inactive state, the fusible element supports the second side of the second plate and the second plate blocks airflow through the second cooling channel, and

wherein when the first heat removal system is in the active state, the fusible element melts and allows the second side of the second plate to fall into the cooling channel and allow airflow through the second cooling channel.

5. The nuclear reactor containment system of claim 1, wherein at least one of the air regulating mechanisms includes:

a second plate structured to be disposed over a second cooling channel of the plurality of cooling channels to block airflow through the second cooling channel,

wherein the second plate is comprised of a melting material,

wherein when the first heat removal system is in the inactive state, the second plate blocks airflow through the second cooling channel, and

wherein when the first heat removal system is in the active state, the second plate is structured to melt and allow airflow through the second cooling channel.

6. The nuclear reactor containment system of claim 1, wherein the at least one heat removal system includes a second heat removal system structured to dissipate heat to ground.

7. The nuclear reactor containment system of claim 6, wherein the second heat removal system includes:

a primary chamber disposed in a bottom portion of the container, the primary chamber having a first material disposed therein; and

a secondary chamber disposed above the primary chamber and around a perimeter of the container, the secondary chamber having a second material disposed therein,

wherein the first material is a porous material having a higher melting point than the second material,

wherein when the second heat removal system is in the inactive state, the second material does not melt, and

wherein when the second heat removal system is in the active state, the second material melts and flows into the primary chamber.

8. The nuclear reactor containment system of claim 7, wherein the first material has a porosity in a range of about 30-80%.

9. The nuclear reactor containment system of claim 7, wherein the second material as at least one of chips, spheres, or powder in its solid state.

10. The nuclear reactor containment system of claim 6, further comprising:

a heat spreader base plate in contact with a bottom surface of the container;

a base area disposed below the container; and

a number of heat conductive plates extending from the heat spreader base plate into the base area.

11. The nuclear reactor containment system of claim 10, wherein the base area is comprised of concrete.

12. The nuclear reactor containment system of claim 1, wherein the container has a substantially cylindrical shape and is comprised of a plurality of layers, the plurality of layers including:

a neutron absorber layer;

a gamma shield layer; and

a container vessel wall.

13. The nuclear reactor containment system of claim 12, wherein the plurality of layers further includes:

a neutron reflector layer.

14. The nuclear reactor containment system of claim 1, further comprising:

an underground vault structured to receive the container, the underground vault including a recess to receive the container and a surrounding barrier area having a plurality of heat conductive plates formed therein.

15. The nuclear reactor containment system of claim 1, further comprising:

a cask structured to receive the container; and

a number of impact limiters structured to limit impacts to the container during transport.

16. The nuclear reactor containment system of claim 1, wherein a top portion of the container includes a lid having a lug, wherein the container is structured to be lifted via the lug.

17. A nuclear reactor containment system comprising:

a nuclear reactor;

a container enclosing the nuclear reactor, the container including;

at least one heat removal system having an active state and an inactive state, wherein the at least one heat removal system dissipates heat from the container more efficiently in the active state than in the inactive state, and wherein the at least one heat removal system is structured to switch from the inactive state to the active state based on a temperature of the container,

wherein the at least one heat removal system includes a first heat removal system structured to dissipate heat to ground

wherein the first heat removal system includes;

a chamber disposed in a bottom portion of the container, the chamber having a top side, a bottom side, and sidewalls;

a flexible liner disposed in the chamber, the flexible liner having a thermally conducting fluid disposed therein; and

thermally expanding elements disposed on the sidewalls of the chamber, the thermally expanding elements being structured to expand inward and reduce an interior volume of the chamber as temperature rises,

wherein when the first heat removal system is in the inactive state, the interior volume of the chamber is large enough that the flexible liner and thermally conducting fluid do not contact the top of the chamber, and

wherein when the first heat removal system is in the active state, the thermally expanding elements expand and reduce the interior volume of the chamber such that the flexible liner and thermally conducting fluid are pressed upward to contact the top of the chamber.