EVACUATED CONTAINMENT VESSEL FOR A NUCLEAR REACTOR

• US 20090161812A1
• Filed: 03/04/2009
• Published: 06/25/2009
• Est. Priority Date: 11/15/2007
• Status: Active Grant

• Current Assignee: NuScale Power, LLC.
• 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 8,588,360 B2
• Time in Patent Office: Days
• US Class Current: 376/277
• CPC Class Codes: G21C 11/08 Thermal shields; Thermal linings, i.e. for dissipating heat from gamma radiation which would otherwise heat an outer biological shield ; Thermal insulation
• CPC Class Codes: G21C 13/00 Pressure vessels; Containment vessels; Containment in general for chemical or physical processes B01J3/00; pressure vessels in general F16J12/00
• CPC Class Codes: G21C 15/18 Emergency cooling arrangements; Removing shut-down heat
• 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 system includes a containment vessel configured to prohibit a release of a coolant, and a reactor vessel mounted inside the containment vessel. An outer surface of the reactor vessel is exposed to below atmospheric pressure, wherein substantially all gases are evacuated from within the containment vessel.

Claims

1. A system comprising:

a containment vessel configured to prohibit a release of a coolant; and

a reactor vessel mounted inside the containment vessel, wherein an outer surface of the reactor vessel is exposed to below atmospheric pressure, and wherein substantially all gases are evacuated from within the containment vessel.

2. The system according to claim 1, further comprising:

a reactor core submerged in the coolant, wherein the coolant is housed within the reactor vessel; and

a steam vent connected to the reactor vessel, wherein when the reactor core becomes over-heated or over-pressurized the steam vent is configured to vent steam into the containment vessel.

3. The system according to claim 2, wherein a condensation of the steam on an interior wall of the containment vessel reduces pressure in the containment vessel at approximately the same rate that the vented steam adds pressure to the containment vessel.

4. The system according to claim 2, wherein the steam is released into the containment vessel to remove a decay heat of the reactor core primarily through condensation of the steam on an inner surface of the containment vessel.

5. The system according to claim 2, wherein the gases that are evacuated from within the containment vessel comprise non-condensable gases, and wherein the containment vessel remains substantially evacuated of all non-condensable gases after the steam is vented into the containment vessel.

6. The system according to claim 2, wherein the evacuated gases comprise oxygen, and wherein any hydrogen that is vented together with the steam is vented at a level that maintains an oxygen-hydrogen mixture within the containment vessel at a non-combustible level without using a hydrogen recombiner.

7. The system according to claim 1, wherein the below atmospheric pressure prohibits substantially all convective heat transfer between the reactor vessel and the containment vessel.

8. The system according to claim 7, wherein the below atmospheric pressure is less than 300 mmHG absolute.

9. The system according to claim 1, wherein an inner surface of the containment vessel substantially surrounds the reactor vessel, and wherein the inner surface of the containment vessel is substantially dry.

10. A method comprising:

maintaining a containment region at a below atmospheric pressure;

identifying a high pressure event for a reactor vessel; and

releasing coolant into the containment region located between a containment vessel and the reactor vessel to remove decay heat from the reactor vessel, wherein the reactor vessel is substantially surrounded by the containment region, and wherein substantially all gases are evacuated from the containment region.

11. The method according to claim 10, further comprising:

condensing the coolant on an inner wall of the containment vessel during an over-pressurization or over-heating event.

12. The method according to claim 10, further comprising:

increasing a pressure within the containment region when the coolant is released until the pressure reaches an upper pressure limit;

prohibiting the release of coolant into the containment region; and

decreasing the pressure through condensation until the pressure reaches a lower pressure limit, wherein the pressure is cyclically increased and decreased by alternatively releasing and prohibiting the release of coolant into the containment region.

13. The method according to claim 10, wherein the below atmospheric pressure prohibits substantially all convective heat transfer between the reactor vessel and the containment vessel prior to releasing the coolant.

14. The method according to claim 13, wherein the below atmospheric pressure is less than 310 mmHG absolute.

15. The method according to claim 10, wherein the evacuated gases comprise non-condensable gases, and wherein the containment region remains substantially evacuated of all non-condensable gases after the coolant is released.

16. The method according to claim 10, wherein the containment region is substantially dry prior to the high pressure event.

17. The method according to claim 10, wherein the evacuated gases comprise air, and wherein the method further comprises:

maintaining levels of oxygen and hydrogen within the containment region below a combustible mixture without employing a hydrogen recombiner, wherein the levels of oxygen and hydrogen are maintained after the coolant is released into the containment region.

18. A reactor module comprising:

a containment vessel;

a reactor vessel mounted inside the containment vessel; and

a containment region located between the reactor vessel and the containment vessel, wherein the containment region substantially surrounds the reactor vessel in a partial vacuum, and wherein the containment region is substantially evacuated of gases during operation of the reactor module to substantially eliminate all convective heat transfer between the reactor core and the reactor vessel.

19. The reactor module according to claim 18, further comprising:

a release valve mounted to the reactor vessel, wherein the release valve is configured to release coolant into the containment region during an emergency condition, and wherein a mixture of hydrogen and oxygen in the containment region is maintained at below combustible limits without the use of a hydrogen recombiner.

20. The reactor module according to claim 18, wherein the partial vacuum is maintained below 300 mmHG absolute during normal operation of the reactor module.