Passive emergency feedwater system

Patent metadata

Field	Value
Publication number	US-9984777-B2
Application number	US-201213425776-A
Country	US
Kind code	B2
Filing date	Mar 21, 2012
Priority date	Nov 15, 2007
Publication date	May 29, 2018
Grant date	May 29, 2018

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.

First claim

The invention claimed is:

1. A power module assembly comprising:
a reactor vessel containing a primary coolant;
a containment vessel surrounding the reactor vessel, wherein the containment vessel is at least partially submerged in a containment cooling pool;
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; and
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 on-site power.

3. 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.

4. 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.

5. 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.

6. The power module assembly according to claim 1 , wherein the containment vessel is configured to completely retain the primary coolant within the containment vessel.

7. The power module assembly according to claim 6 , wherein the reactor vessel is configured to completely retain the primary coolant within the reactor vessel both prior to and during the loss of power event.

8. The power module assembly according to claim 1 , wherein the containment vessel is internally dry.

9. A power module assembly for use in a containment cooling pool containing emergency feedwater, the power module assembly comprising:
a reactor vessel containing a primary coolant;
means for removing heat from the primary coolant;
a containment vessel surrounding the reactor vessel, wherein the containment vessel is at least partially submerged in the containment cooling pool;
means for drawing the emergency feedwater from the 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.

10. The power module assembly according to claim 9 , 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.

11. The power module assembly according to claim 9 , 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.

12. The power module assembly according to claim 9 , 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.

13. The power module assembly according to claim 9 , wherein the containment vessel is configured to prohibit a release of the primary coolant into the containment cooling pool.

14. The power module assembly according to claim 9 , wherein the containment vessel is internally dry.

15. A power module assembly comprising:
a reactor vessel containing a primary coolant;
a containment cooling pool containing emergency feedwater;
a containment vessel surrounding the reactor vessel, wherein the containment vessel is at least partially submerged in the containment cooling pool;
one or more inlets configured to draw the emergency feedwater 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 emergency feedwater back into the containment cooling pool; and
a heat exchanger configured to circulate the emergency feedwater from the one or more inlets, through the reactor vessel, and out the one or more outlets without intermixing the primary coolant and the emergency feedwater.

16. The power module assembly according to claim 15 , wherein the primary coolant is completely retained within the containment vessel both prior to and during the loss of power event.

17. The power module assembly according to claim 15 , wherein the containment vessel is internally dry both prior to and during the loss of power event.

18. The power module assembly according to claim 15 , wherein the heat exchanger is configured to circulate the emergency feedwater without using a pump.

19. The power module assembly according to claim 15 , wherein the emergency feedwater is vented into the containment cooling pool after passing through the heat exchanger.

20. The power module assembly according to claim 15 , wherein the emergency feedwater circulates through the heat exchanger 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 one or more inlets and the one or more outlets.

Assignees

• Reyes Jose N
• Groome John T
• Nuscale Power Llc

Inventors

• Reyes Jose N
• Groome John T

Classifications

• Y02E30/40

  Cross-Sectional Technologies · mapped topic

• G21C15/26

  by convection, e.g. using chimneys, using divergent channels · CPC title

• G21C1/32

  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 title

• G21C15/18 Primary

  Emergency cooling arrangements; Removing shut-down heat · CPC title

• Y02E30/30

  Nuclear fission reactors · CPC title