PASSIVE EMERGENCY FEEDWATER SYSTEM

• US 20120177168A1
• Filed: 03/21/2012
• Published: 07/12/2012
• 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: Reyes, Jose N. Jr., Groome, John T.
• Granted Patent: US 9,984,777 B2
• Time in Patent Office: Days
• US Class Current: 376/293
• 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: Y02E 30/30 Nuclear fission reactors

Abstract

A power module assembly may include a reactor vessel containing a primary coolant and one or more inlets configured to draw a secondary coolant from the containment cooling pool in response to a loss of power and/or a loss of coolant. One or more outlets may be submerged in the containment cooling pool and may be configured to vent the secondary coolant into the containment cooling pool. A heat exchanger may be configured to remove heat from the primary coolant, wherein the heat may be removed by circulating the secondary coolant from the containment cooling pool through the heat exchanger via natural circulation.

Claims

1. A power module assembly comprising:

a reactor vessel containing a primary coolant;

one or more inlets configured to draw a secondary coolant from the containment cooling pool in response to a loss of power event;

one or more outlets submerged in the containment cooling pool and configured to vent the secondary coolant into the containment cooling pool;

a heat exchanger configured to remove heat from the primary coolant, wherein the heat is removed by circulating the secondary coolant from the containment cooling pool through the heat exchanger via natural circulation and without intermixing the primary coolant and the secondary coolant.

2. The power module assembly according to claim 1, wherein the loss of power event comprises a loss of off-site power.

3. The power module assembly according to claim 1, wherein the loss of power event comprises a loss of on-site power.

4. The power module assembly according to claim 1, wherein the secondary coolant is vented into the containment cooling pool after passing through the heat exchanger.

5. The power module assembly according to claim 1, wherein the secondary coolant circulates through the heat exchanger by the natural circulation due to both a temperature difference between the secondary coolant and the primary coolant and a difference in elevation between the one or more inlets and the one or more outlets.

6. The power module assembly according to claim 1, wherein the natural circulation comprises a circulation path of the secondary coolant entering the one or more inlets, passing through the heat exchanger, exiting the one or more outlets, and re-entering the one or more inlets.

7. The power module assembly according to claim 1, further comprising a containment vessel surrounding the reactor vessel, wherein the containment vessel is submerged in the containment cooling pool.

8. The power module assembly according to claim 7, wherein the containment vessel is configured to completely retain the primary coolant within the containment vessel during the loss of power event.

9. The power module assembly according to claim 8, wherein the reactor vessel is configured to completely retain the primary coolant within the reactor vessel prior to the loss of power event.

10. The power module assembly according to claim 7, wherein the containment vessel is internally dry prior to the loss of power event.

11. A power module assembly comprising:

a reactor vessel containing a primary coolant;

means for removing heat from the primary coolant;

means for drawing emergency feedwater from a containment cooling pool in response to a loss of power event;

means for venting the emergency feedwater into the containment cooling pool, wherein the means for venting is submerged in the containment cooling pool; and

means for circulating the emergency feedwater from the containment cooling pool through the means for removing heat and back to the containment cooling pool without intermixing the primary coolant and the emergency feedwater, wherein the emergency feedwater is circulated through natural circulation.

12. The power module assembly according to claim 11, wherein the means for drawing is submerged in the containment cooling pool, and wherein the means for drawing is positioned at an elevation in the containment cooling pool that is lower than an elevation of the means for venting.

13. The power module assembly according to claim 11, wherein the natural circulation is due to an elevation difference between the means for drawing and the means for venting, and wherein the natural circulation is further due to a difference in density of the emergency feedwater that is vented from the means for venting and the emergency feedwater that is drawn from the containment cooling pool.

14. The power module assembly according to claim 11, wherein the emergency feedwater circulates through the means for removing heat by the natural circulation due to both a temperature difference between the emergency feedwater and the primary coolant and a difference in elevation between the means for drawing and the means for venting.

15. The power module assembly according to claim 11, wherein the means for drawing does not comprise a pump.

16. The power module assembly according to claim 11, further comprising a containment means submerged in the containment cooling pool and configured to prohibit a release of the primary coolant into the containment cooling pool during the loss of power event.

17. The power module assembly according to claim 16, wherein the containment means surrounds the reactor vessel, and wherein the containment means is internally dry prior to the loss of power event.

18. A method of removing heat from a primary coolant contained within a reactor vessel, comprising:

drawing emergency feedwater into one or more inlets from a containment cooling pool in response to a loss of power event;

venting the emergency feedwater from one or more vents into the containment cooling pool, wherein the one or more vents are submerged in the containment cooling pool; and

circulating the emergency feedwater from the containment cooling pool through the reactor vessel and back to the containment cooling pool without intermixing the primary coolant and the emergency feedwater, wherein the emergency feedwater is circulated through natural circulation.

19. The method according to claim 18, wherein the reactor vessel is contained within a containment vessel submerged in the containment cooling pool, and wherein the primary coolant is completely retained within the containment vessel both prior to and during the loss of power event.

20. The power module assembly according to claim 19, wherein the containment vessel is internally dry prior to the loss of power event.