B&w Fuel Company

Framatome Technologies, Inc.

Jeffrey S Whitt

William E Bailey

Douglas W Bell

Michael W Anderson

A grid keying fixture for installing grid keys in a nuclear fuel assembly spacer grid having a matrix of cells, at least some of the cells including a soft stop in a first axis and a soft stop in a second axis. The grid keying fixture includes a frame assembly having a plurality of fixture pegs affixed to the frame assembly and each arranged and adapted to enter a respective cell of the grid. Each of the fixture pegs is operable to simultaneously deflect the first axis soft stop and the second axis soft stop of the respective cell without bearing on a hard stop in the respective cell opposite one of the first axis and second axis soft stops. In the preferred embodiment, alignment pegs are affixed to the frame assembly for aligning the fixture pegs with the respective cells.

Multi-axis spacer grid keying fixture

A modular grid welding fixture for a spacer grid that facilitates full grid laser welding of a spacer grid in one setup. The modular design allows for partial implementation of each weld type. A base plate is used for mounting to the positioning/rotational plate of the welding system. A removable sub-plate received in the base plate is used to position the grid strips for proper location for welding. A top fixture plate is aligned with the base plate and provides for mounting of a second sub-plate if required. Side plates with spring loaded pressure pads that are hinged to the top fixture plate apply uniform pressure to the outer grid strips during processing. The base plate, top plate, side plate, and pressure pads are provided with a plurality of through holes to allow access of the laser beam for welding. Corner clips are used to insure contact of the overlapping sections of the outer grid strips for proper corner welding.

Grid welding fixture for a spacer grid

A grid key for interior grid cells. A rectangular main body portion is bent near the middle at approximately a 90 degree angle. Two tabs that are flush with the main body portion extend outward in opposite directions from one end and along a portion of the length of the main body portion. The opposing side of the tabs is tapered at a 45 degree angle back toward the main body portion. The main body portion has a thickened section that coincides with the tabs. The thickened section is wedged between the soft stops of an individual interior grid cell to retract the stops and allow loading of a fuel rod.

Grid key for interior grid cells

A grid key and method for keying exterior grid cells in a nuclear fuel assembly. The grid key has a main body portion having first and second ends and is bent at approximately a 45 degree angle near the first end. Two tabs extend outward from the first end at a right angle to the main body portion to define a T-shape. The T-shaped end is inserted into the window of the exterior grid strip such that the top of the T-shape is parallel to the longitudinal axis of the grid assembly. The main body portion is then rotated 90 degrees to position the top of the T-shaped end to be perpendicular to the longitudinal axis of the grid assembly and behind the exterior grid strip. The main body portion is then pulled away from the exterior grid strip in a vertical rotating motion, causing the top of the T-shaped end to pull the exterior grid strip away from the center of the cell defined by the grid assembly.

Grid key for exterior grid cells

A grid key and method for keying exterior grid cells in a nuclear fuel assembly. The grid key has a main body portion having first and second ends and is bent at approximately a 45 degree angle near the first end. Two tabs extend outward from the first end at a right angle to the main body portion to define a T-shape. The T-shape end is inserted into the window of the exterior grid strip such that the top of the T-shape is parallel to the longitudinal axis of the grid assembly. The main body portion is then rotated 90 degrees to position the top of the T-shaped end to be perpendicular to the longitudinal axis of the grid assembly and behind the exterior grid strip. The main body portion is then pulled away from the exterior grid strip in a vertical rotating motion, causing the top of the T-shaped end to pull the exterior grid strip away from the center of the cell defined by the grid assembly.

Growing community of inventors

Lynchburg, VA, United States of America

Jeffrey S Whitt