Exxon Nuclear Company, Inc.

Siemens Power Corporation, Inc.

John W Long

Barney S Flora

David W Christiansen

Kenneth L Ford

A nuclear fuel assembly for a pressurized water reactor having lower and upper tie plates, guide tubes, spacer grids, an instrumentation tube, and extended fuel rods which extend to the lower tie plate and which are spaced radially and supported along the guide tubes by the spacer grids, at least one of the extended fuel rods having at a lower end a fuel rod lower end cap secured by a first spring within an aperture in the lower tie plate and which exerts a lateral force against the lower end cap. The upper tie plate further includes a fuel rod support housing which extends down over the upper end of the at least one of the extended fuel rods and has a second spring positioned in a bore in the fuel rod support housing which exerts a lateral force on the upper end of the extended fuel rod positioned within the bore in the fuel rod support housing.

Nuclear fuel assembly for a pressurized water reactor

A boiling water reactor fuel assembly having a lowered fuel rod support plate and increased fuel rod length while restraining the fuel rods against lateral vibration.

BWR nuclear fuel assembly

In a nuclear power reactor fuel bundle having tie rods fastened to a lower tie plate and passing through openings in the upper tie plate, the assembled bundle is secured by locking lugs fixed to rotatable locking sleeves which engage the upper tie plate. Pressure exerted by helical springs mounted around each of the tie rods urge retaining lugs fixed to a retaining sleeve associated with respective tie rods into a position with respect to the locking sleeve to prevent accidental disengagement of the upper plate from the locking lugs. The bundle may be disassembled by depressing the retaining sleeves and rotating the locking lugs to the disengaged position, and then removing the upper tie plate.

Assembly mechanism for nuclear fuel bundles

A spacer capture system for nuclear fuel assemblies of the type in which fuel rods are disposed in parallel array between supporting end plates. At intervals along the fuel rods spacer grids are provided which properly position the fuel rods, reducing vibration and obtaining proper spacing to assure uniform heat removal from the fuel rods during operation. The spacers hold the fuel rods by spring pressure against protrusions formed from the side walls of the grids. The spacers are held in the proper position against vibration and the force of water passing adjacent the tubes by lugs provided on special fuel containing spacer capture rods which engage the protrusions on each spacer and thereby preventing its longitudinal movement relative to the fuel rods. The lugs are so mounted as to permit freeing of the spacer capture rods by a 45.degree. rotation of the spacer capture rods and conversely, the spacers may be locked in position by a 45.degree. rotation of the spacer capture rods from the unlocked position. In a region in which the locking lugs are provided, inert material replaces the nuclear fuel material in order to avoid overheating of the tubes.

Spacer capture system for nuclear fuel assemblies

In a nuclear power reactor fuel bundle having tie rods fastened to a lower tie plate and passing through openings in the upper tie plate, the assembled bundle is secured by rotatable locking sleeves which engage slots provided in the upper tie plate. Pressure exerted by helical springs mounted around each of the fuel rods urge the upper tie plate against the locking sleeves. The bundle may be disassembled after depressing the upper tie plate and rotating the locking sleeves to the unlocked position.

Growing community of inventors

Richland, WA, United States of America

John W Long