PASSIVE EMERGENCY FEEDWATER SYSTEM

• US 20120294408A1
• Filed: 04/23/2012
• Published: 11/22/2012
• Est. Priority Date: 11/15/2007
• Status: Active Grant

• Current Assignee: NuScale Power, LLC. (Fluor Enterprises, Inc.)
• Original Assignee: University (290275) (Independent Bank Group Incorporated), Oregon State University (Oregon University System)
• Inventors: Groome, John T., REYES, Jose N. Jr.
• Granted Patent: US 8,731,130 B2
• Time in Patent Office: Days
• US Class Current: 376/282
• CPC Class Codes: G21C 1/32 Integral reactors, i.e. reactors wherein parts functionally associated with the reactor but not essential to the reaction, e.g. heat exchangers, are disposed inside the enclosure with the core G21C1/02 - G21C1/30 take precedence
• CPC Class Codes: G21C 15/18 Emergency cooling arrangements; Removing shut-down heat
• CPC Class Codes: G21C 15/26 by convection, e.g. using chimneys, using divergent channels
• CPC Class Codes: G21C 9/00 Emergency protection arrangements structurally associated with the reactor , e.g. safety valves provided with pressure equalisation devicesemergency cooling arrangements G21C15/18
• CPC Class Codes: G21C 9/012 by thermal accumulation or by steam condensation, e.g. ice condensers
• CPC Class Codes: Y02E 30/30 Nuclear fission reactors

Abstract

A power module assembly includes a reactor vessel containing a reactor core surrounded by a primary coolant. A containment vessel is adapted to be submerged in a containment cooling pool and to prohibit a release of the primary coolant outside of the containment vessel. A secondary cooling system is configured to remove heat generated by the reactor core. The heat is removed by circulating liquid from the containment cooling pool through the primary coolant.

Claims

1. A power module assembly comprising:

a primary cooling circuit comprising a reactor vessel and a reactor core surrounded by a primary coolant, the primary cooling circuit configured to promote a natural circulation flowpath within the reactor vessel;

a containment vessel submerged in a containment cooling pool and configured to prohibit release of the primary coolant outside of the containment vessel;

a heat exchanger disposed within the containment vessel in fluid communication with the primary coolant, the heat exchanger configured to remove heat from the primary coolant;

a secondary cooling circuit including a steam generation circuit configured to generate steam, using heat extracted from the primary coolant, to drive a turbine;

an emergency cooling system, isolated from the steam generation circuit, and configured to be coupled to the heat exchanger during emergency operation to remove heat from the primary coolant via natural circulation of an emergency coolant, without a pump or external power source.

2. The power module assembly of claim 1, wherein the steam generation circuit further comprises an accumulator tank.

3. The power module assembly of claim 1, wherein the emergency cooling system comprises at least one valve that isolates the emergency cooling system from the steam generation circuit during emergency operation.

4. The power module assembly of claim 1, wherein the emergency coolant circulates through the heat exchanger by the natural circulation induced by a temperature difference between the emergency coolant and the primary coolant.

5. The power module assembly of claim 1, wherein heat removed from the primary coolant is deposited in the containment cooling pool.

6. The power module assembly of claim 1 wherein the emergency coolant comprises coolant drawn from the containment cooling pool.

7. The power module assembly of claim 1 wherein the emergency coolant enters the emergency cooling circuit via an inlet disposed in the containment cooling pool.

8. The power module assembly of claim 7 wherein the emergency coolant exits the emergency cooling circuit via an outlet disposed in the containment cooling pool.

9. The power module assembly of claim 8, wherein the outlet is positioned at an elevation of the containment cooling pool that is above an elevation of the inlet, and wherein the emergency coolant circulates through the primary coolant by the natural circulation at least partly due to an elevation difference between the inlet and the outlet.

10. The power module assembly of claim 1, wherein the emergency cooling circuit further comprises an inlet line configured to deliver the emergency coolant from an inlet to the heat exchanger and an outlet line connecting the heat exchanger to an outlet.

11. The power module assembly of claim 1, wherein the containment vessel is internally dry before emergency operation.

12. A power module assembly comprising:

a reactor vessel containing a reactor core surrounded by a primary coolant, internal structures within the reactor vessel configured to promote natural circulation of the primary coolant;

containment means configured to prohibit a release of the primary coolant into a surrounding containment cooling pool;

a heat exchanger disposed in fluid communication with the primary coolant to remove heat generated by the reactor core;

a steam generation circuit configured to generate steam, using heat extracted from the primary coolant, to drive a turbine; and

an emergency cooling circuit, isolated from the steam generation circuit, and configured to be coupled to the heat exchanger during emergency operation to circulate an emergency coolant to remove heat from the primary coolant,

wherein the emergency coolant is circulated through the heat exchanger and the emergency cooling circuit via natural circulation.

13. The power module assembly of claim 12, wherein the emergency cooling circuit comprises an inlet submerged in the containment cooling pool.

14. The power module assembly of claim 13, wherein the emergency cooling circuit further comprises an outlet positioned at an elevation in the containment cooling pool that is higher than an elevation of the inlet.

15. The power module assembly of claim 13, wherein natural circulation is established in the emergency cooling system at least partly due to a difference in density of the emergency coolant at the inlet and the emergency coolant at the outlet.

16. The power module assembly of claim 12, wherein the containment vessel is internally dry before emergency operation.

17. The power module assembly of claim 12, wherein the emergency cooling circuit further comprises at least one valve that isolates the emergency cooling system from the steam generation circuit during emergency operation.

18. The power module assembly of claim 12, wherein heat removed from the primary coolant is deposited in the containment cooling pool.

19. The power module assembly of claim 12, wherein the steam generation circuit further comprises an accumulator tank.

20. The power module assembly of claim 12, wherein the emergency cooling circuit further comprises an inlet line configured to deliver the emergency coolant from an inlet to the heat exchanger and an outlet line connecting the heat exchanger to an outlet.