Weld repair systems and methods for use in a nuclear reactor jet pump

Patent metadata

Field	Value
Publication number	US-11112052-B2
Application number	US-201715473903-A
Country	US
Kind code	B2
Filing date	Mar 30, 2017
Priority date	Mar 30, 2017
Publication date	Sep 7, 2021
Grant date	Sep 7, 2021

Abstract

Systems repair jet pump elbow joining structures like RS1 and RS2 welds. Systems include a base having legs that secure to ends of the elbow in different directions, and a drive plate that joins to flow conduits where they meet the elbow. The drive plate and base may then be pushed together, resulting in compression or joining of the elbow and flow conduit. Multiple drive plates may be used with a single base to compress multiple flow conduits to the base. The base and the drive plates can be driven together with a driving bolt extending through the base and driving plate. To provide a better fit, grooves can be created in the flow conduits through machining from the installed base. The drive plate may be seated into the groove to achieve a desired orientation with less slippage. Example embodiments and methods do not require welding or a welding base.

First claim

What is claimed is:

1. A system for repairing a jet pump elbow having at least one of, a first weld connecting the elbow to a first conduit extending in a first direction from the elbow, and a second weld connecting the elbow to a second conduit extending in a second direction from the elbow, the system comprising:
a single-piece base having a first leg shaped to secure in the first direction around the elbow at the first weld and a second leg shaped to secure in the second direction around the elbow at the second weld; and
a drive plate shaped to secure around at least one of the first conduit at the first weld and the second conduit at the second weld, wherein the drive plate and the base are configured to bias against each other so as to compress the at least one of the first conduit and the second conduit into the elbow.

2. The system of claim 1 , wherein the first conduit is a thermal sleeve configured to provide feedwater, and wherein the second conduit is a riser configured to flow the feedwater vertically against gravity in the jet pump.

3. The system of claim 1 , wherein the at least one first conduit and second conduit includes a locking groove at the first or the second weld, and wherein the drive plate includes a locking tongue shaped to seat into the locking groove to prevent relative movement of the drive plate and the at least one first and second conduit.

4. The system of claim 1 , wherein the drive plate includes two sections that are removably joinable, and wherein the two sections joined define a perimeter matching a perimeter of one of the first and the second conduits.

5. The system of claim 1 , wherein the base and the drive plate define a plurality of bosses passing continuously through the base and the drive plate when joined at opposite sides of the first weld, the system further comprising:
a plurality of driving bolts, each shaped to pass through one of the bosses, wherein the driving bolts are configured to bias the drive plate and the base toward each other.

6. The system of claim 1 , further comprising:
a first clamp wing and a second clamp wing, wherein the first clamp wing and the second clamp wing are removably joinable to the base.

7. The system of claim 6 , further comprising:
a plurality of draw bolts passing through the base and at least one of the first clamp wing and the second clamp wing, wherein the draw bolts are configured to drive the first clamp wing and the second clamp wing to the base when tightened.

8. The system of claim 1 , wherein the drive plate is shaped to secure around the first conduit at the first weld, the system further comprising:
an additional drive plate shaped to secure around the second conduit at the second weld, wherein the additional drive plate is configured to bias against the base so as to compress the second conduit into the elbow.

9. The system of claim 8 , wherein the first direction and the second direction are substantially 90 degrees apart.

10. The system of claim 9 , wherein the drive plate is configured to secure around the first conduit in the second direction and compress the first conduit in the first direction into the elbow, and wherein the additional drive plate is configured to secure around the second conduit in the first direction and compress the second conduit in the second direction into the elbow.

11. A method of repairing one or more welds on a jet pump elbow, the method comprising:
securing a base having a first leg and a second leg to the elbow such that the first leg passes around a first portion of the elbow extending in a first direction and the second leg of the elbow passes around a second portion of the elbow extending in a second direction;
securing a first drive plate to a first conduit extending in the first direction from the first portion of the elbow; and
biasing the first drive plate and the first leg of the base together in the first direction so as to compress the second leg of the base into the second portion of the elbow in the first direction.

12. The method of claim 11 , wherein the first conduit is at least one of a riser flowing vertically upward against gravity from the elbow and a thermal sleeve flowing horizontally into the elbow, and wherein the end of the first conduit includes a weld joining the first conduit to the elbow.

13. The method of claim 11 , wherein the securing the base includes clamping a first clamp wing to a clamp center around the elbow at the first portion of the elbow and clamping a second clamp wing to the clamp center around the elbow at the second portion of the elbow.

14. The method of claim 11 , wherein the securing the first drive plate includes clamping a first section and a second section of the first drive plate around the conduit.

15. The method of claim 11 , wherein the biasing the first drive plate and the base together includes tensioning a plurality of driving bolts extending through the first drive plate and the base.

16. The method of claim 11 , wherein the method does not include welding or installing a welding base.

17. The method of claim 11 , further comprising:
securing a second drive plate to a second conduit extending in the second direction from the elbow; and
biasing the second drive plate and the second leg of the base together in the second direction so as to compress the first leg of the base into the first portion of the elbow in the second direction.

18. The method of claim 17 , wherein the first direction and the second direction are substantially perpendicular to each other.

19. The method of claim 11 , further comprising:
forming a locking groove in the first conduit where the first drive plate secures to the first conduit, wherein the securing the first drive plate includes inserting a locking tongue of the first drive plate into the locking groove.

20. The method of claim 19 , wherein the forming the locking groove uses electrical discharge machining the groove into the first conduit, and wherein the electrical discharge machining includes using the base as a machining base.

Assignees

• Ge Hitachi Nuclear Energy Americas Llc

Inventors

• Mosier Sean T
• Nelson Bret E

Classifications

• F04F5/44 Primary

  Component parts, details, or accessories not provided for in, or of interest apart from, groups F04F5/02 - F04F5/42 · CPC title

• G21C13/032

  Joints between tubes and vessel walls, e.g. taking into account thermal stresses · CPC title

• F16L55/168

  from outside the pipe (specially adapted for bends, branch units, branching pipes, or the like F16L55/179) · CPC title

• F04F5/10

  displacing liquids, e.g. containing solids, or liquids and elastic fluids · CPC title

• F16L43/001

  made of metal · CPC title