NUCLEAR REACTOR SHROUD

• US 20200135349A1
• Filed: 11/25/2019
• Published: 04/30/2020
• Est. Priority Date: 02/27/2013
• Status: Active Grant

• Current Assignee: Smr Inventec, LLC
• Original Assignee: Smr Inventec, LLC
• Inventors: Singh, Krishna P., Rampall, Indresh, Rajkumar, Joseph Gerald Leo
• Granted Patent: US 11,289,219 B2
• Time in Patent Office: Days
• CPC Class Codes: G21C 13/02 Details
• CPC Class Codes: G21C 15/24 Promoting flow of the coolant electrodynamic pumps H02K44/02
• CPC Class Codes: G21C 15/243 for liquids
• CPC Class Codes: G21C 9/04 Means for suppressing fires ; Earthquake protection
• CPC Class Codes: Y02E 30/30 Nuclear fission reactors

Abstract

A nuclear reactor in one embodiment includes a cylindrical body having an internal cavity, a nuclear fuel core, and a shroud disposed in the cavity. The shroud comprises an inner shell, an outer shell, and a plurality of intermediate shells disposed between the inner and outer shells. Pluralities of annular cavities are formed between the inner and outer shells which are filled with primary coolant such as demineralized water. The coolant-filled annular cavities may be sealed at the top and bottom and provide an insulating effect to the shroud. In one embodiment, the shroud may comprise a plurality of vertically-stacked self-supported shroud segments which are coupled together.

Claims

1. A method for assembling a shroud for a nuclear reactor vessel, the method comprising:

providing a first shroud segment and a second shroud segment, each shroud segment including a top closure plate and a bottom closure plate;

abutting the top closure plate of the second shroud segment against the bottom closure plate of the first shroud segment;

axially aligning a first mounting lug on the first shroud segment with a second mounting lug on the second shroud; and

locking the first mounting lug to the second mounting lug to couple the first and second shroud segments together.

2. The method according to claim 1, wherein the locking step is preceded by a step of pivoting a mounting clamp movably coupled to the first shroud segment about a fixed pivot axis from an unlocked open position to a locked closed position.

3. The method according to claim 2, wherein the pivoting step includes receiving the first and second mounting lugs into a recess formed in the mounting clamp.

4. The method according to claim 3, wherein the locking step further includes tightening a locking fastener and engaging the fastener with the first or second locking lugs through the clamp to retain the clamp in the locked closed position.

5. The method according to claim 4, wherein the fastener is a vertically oriented set screw rotatably received through a corresponding threaded bore of the clamp.

6. The method according to claim 5, wherein the set screw is projectible into and retractable from the recess of the clamp via rotating the set screw.

7. The method according to claim 5, wherein the set screw is located proximate to a first end of the clamp and the fixed pivot axis is located proximate to an opposite second end of the clamp and formed on the first mounting lug of the first shroud segment.

8. The method according to claim 3, wherein the fixed pivot axis is formed on the first mounting lug of the first shroud segment.

9. The method according to claim 3, wherein the clamp is C-shaped.

10. The method according to claim 9, wherein the recess is laterally open to receive the first and second mounting lugs.

11. The method according to claim 3, wherein the fixed pivot axis is formed by a pivot pin extending axially through the clamp and the first mounting lug of the first shroud segment.

12. The method according to claim 11, wherein the pivot pin extends through a pair of spaced apart flanges of the clamp which define the recess.

13. The method according to claim 3, wherein the first mounting lug is integrally formed with the bottom closure plate of the first shroud segment and the second mounting lug is integrally formed with the top closure plate of the second shroud segment.

14. The method according to claim to claim 13, wherein the first and second mounting lugs extend radially outwards.

15. The method according to claim 2, wherein the mounting clamp further includes a fixedly attached and vertical arcuately shaped seismic restraint arranged to engage an interior surface of the reactor vessel, the seismic restraint being pivotably movable with the clamp between the locked and unlocked positions.

16. A method for assembling a shroud for a nuclear reactor vessel, the method comprising:

providing a first shroud segment and a second shroud segment, each shroud segment including a top closure plate and a bottom closure plate;

abutting the top closure plate of the second shroud segment against the bottom closure plate of the first shroud segment;

axially aligning a first plurality of circumferentially spaced apart radial mounting lugs on the bottom closure plate of the first shroud segment with a second plurality of circumferentially spaced apart radial mounting lugs on the top closure plate of the second shroud segment; and

locking each of the first plurality of mounting lugs to the second plurality of mounting lugs with a mounting clamp to couple the first and second shroud segments together.

17. The method of claim 16, wherein the locking step is preceded by a step of swinging a mounting clamp pivotably coupled to each of the first plurality of mounting lugs about a fixed pivot axis from an outward unlocked open position to an inward locked closed position engaged with the second plurality of mounting lugs.

18. The method of claim 17, wherein the swinging step includes receiving a pair of the first and second plurality of mounting lugs into a locking recess formed in each of the mounting clamps.

19. The method of claim 18, wherein the locking step further includes tightening a threaded fastener rotatably coupled to each of the mounting clamps to retain the clamp in the inward locked closed position.

20. The method according to claim 18, wherein the mounting clamps are C-shaped and the locking recesses formed between top and bottom flanges of each mounting clamp.