Spacer grid welding fixture

Patent metadata

Field	Value
Publication number	US-2020376610-A1
Application number	US-202016998689-A
Country	US
Kind code	A1
Filing date	Aug 20, 2020
Priority date	Mar 14, 2013
Publication date	Dec 3, 2020
Grant date	—

Abstract

A spacer grid welding fixture comprises a frame sized to receive an assembled spacer grid comprising a first set of parallel straps and a second set of parallel straps oriented orthogonally to the first set of parallel straps, the first and second sets of parallel straps interlocked together by slots cut into the straps. A first set of grid engagement bars is placed on a first side of the spacer grid with each grid engagement bar arranged parallel with the straps of the first set of parallel straps and engaging the straps of the second set of parallel straps. A second set of grid engagement bars is placed on an opposite second side of the spacer grid with each grid engagement bar arranged parallel with the straps of the second set of parallel straps and engaging the straps of the first set of parallel straps.

First claim

1 . A spacer grid welding fixture comprising:
a frame sized to receive an assembled spacer grid comprising a first set of parallel straps and a second set of parallel straps oriented orthogonally to the first set of parallel straps, the first and second sets of parallel straps interlocked together by slots cut into the straps; a first set of grid engagement bars placed on a first side of the spacer grid, each grid engagement bar of the first set of grid engagement bars being arranged parallel with the straps of the first set of parallel straps and engaging the straps of the second set of parallel straps; and a second set of grid engagement bars placed on an opposite second side of the spacer grid, each grid engagement bar of the second set of grid engagement bars being arranged parallel with the straps of the second set of parallel straps and engaging the straps of the first set of parallel straps.

2 . The spacer grid welding fixture of claim 1 wherein ends of the grid engagement bars nest into slots of the frame.

3 . The spacer grid welding fixture of claim 2 further comprising:
retaining bars securing the ends of the grid engagement bars to the frame.

4 . A method comprising:
securing an assembled spacer grid comprising a first set of parallel straps and a second set of parallel straps oriented orthogonally to the first set of parallel straps in a spacer grid welding fixture as set forth in claim 1 ; welding the assembled spacer grid while secured in the spacer grid welding fixture to form a welded spacer grid; and removing the welded spacer grid from the spacer grid welding fixture.

5 . The method of claim 4 wherein the securing comprises:
(i) placing the assembled spacer grid in the frame of the spacer grid welding fixture with the first side of the spacer grid exposed;
(ii) placing the first set of grid engagement bars on the first side of the spacer grid and securing the ends of the first set of grid engagement bars to the frame of the spacer grid welding fixture; and
(iii) placing the second set of grid engagement bars on the second side of the spacer grid and securing the ends of the second set of grid engagement bars to the frame of the spacer grid welding fixture.

6 . The method of claim 5 including flipping the frame over between placement operations (ii) and (iii).

7 . A method comprising:
(i) disposing an assembled spacer grid comprising a first set of parallel straps and a second set of parallel straps oriented orthogonally to the first set of parallel straps and interlocked with the first set of parallel strips by slots cut into the straps in a frame of a spacer grid welding fixture; and (ii) after performing operation (i), disposing grid engagement bars onto the assembled spacer grid with grooves of the grid engagement bars engaging straps of the assembled spacer grid that are oriented orthogonally to the grid engagement bar and with ends of the grid engagement bars nesting into slots in the frame of the spacer grid welding fixture.

8 . The method of claim 7 wherein the operation (ii) comprises:
(iia) disposing a first set of mutually parallel grid engagement bars onto a first side of the assembled spacer grid; and
(iib) disposing a second set of mutually parallel grid engagement bars onto a second side of the assembled spacer grid opposite the first side of the assembled spacer grid with the second set of mutually parallel grid engagement bars being disposed orthogonally to the first set of mutually parallel grid engagement bars.

9 . The method of claim 7 further comprising:
after performing operation (ii), securing retaining bars onto the frame to lock the ends of the grid engagement bars into the slots in the frame of the spacer grid welding fixture.

10 . The method of claim 7 further comprising:
after performing operation (ii), securing the ends of the grid engagement bars into the slots in the frame of the spacer grid welding fixture.

11 . The method of claim 10 further comprising:
after securing the ends of the grid engagement bars into the slots in the frame of the spacer grid welding fixture, welding junctions between straps of the assembled spacer grid.

12 . The method of claim 11 wherein the welding further comprises:
welding guide tubes to the assembled spacer grid to form a structural skeleton for a fuel assembly.

13 . The method of claim 12 further comprising:
loading fuel rods comprising fissile 235 U into the structural skeleton to generate a nuclear reactor fuel assembly.

Assignees

• Bwxt Mpower Inc

Inventors

• Ridgeway Roger D
• Austin Jeffrey W
• Lee Jeffrey T

Classifications

• Y02E30/30

  Nuclear fission reactors · CPC title

• B23K2101/24

  Frameworks · CPC title

• B23K37/0408 Primary

  for planar work · CPC title

• B23K37/0443

  Jigs · CPC title

• B23K37/04 Primary

  for holding or positioning work · CPC title