General Electric Company

Andrew A Lingenfelter

David Grey Smith

John L Harmon

Jaime A Zuloaga, Jr

Robert A Haughton

Johnny R Skipper

Harold B King

William C Peters

Michael T Kiernan

Edward G Apple

Jeffrey A Wilson

Jeffrey P Johnson

Robert J Sziemkiewicz

Harry L Batson

James M Gehr

Michelle Wagner

A high pressure laser welding method and apparatus enables seam welding of a nuclear fuel rod at hyperbaric pressure. In an automatic process, a loaded fuel rod and an upper end plug are mated within a sealable weld box. A pressure within the weld box is controlled relative to a pressure within the fuel rod, and a laser assembly welds the seam at hyperbaric pressure. Helium flowing through a laser window nozzle during welding prevents soot contamination of the laser window glass and prevents formation of ionic plasma. The upper end plug fuel rod welding operation is thus reduced to a single step and eliminates inspection related tasks with respect to a sealed hole.

High pressure laser welding of nuclear fuel rods

A swirler is releasably attached to a spacer and lies in the opening through the spacer lying above a part-length fuel rod in a nuclear fuel bundle. Adjacent ferrules have upstanding tabs with loops forming part of connecting elements for releasably securing the swirler to the spacer. The spacer is mounted on a mounting ring having radially outwardly directed elements terminating in barbed ends for insertion through the loops in response to rotation of the swirler mounting ring relative to the tabs. The barbed ends can be squeezed together to release the swirler from its attachment with the spacer.

Swirler attachment for a spacer of a nuclear fuel bundle

End plugs for nuclear fuel rods are provided with a spot weld along the interior end face of the end plugs to seal any streamer openings or passages along the axis of the end plugs, thereby maintaining the fuel rods sealed at its opposite ends. The spot welds are applied by an automated laser welding system in which pallets of end plugs are supported on X-Y positioning tables below a laser movable in a vertical direction. By successively locating the end plugs in the pallet below the laser, the spot welds are formed along the axis of the end plugs and along the interior faces thereof sealing the end plugs.

Apparatus and methods for sealing end plugs for nuclear fuel rods

To inspect the integrity of pressurization holes in nuclear fuel rod final end plugs, quality assurance apparatus includes an adapter providing a test chamber into which an end plug is inserted. Instrument gas is introduced into the test chamber through an inlet port for flow to the atmosphere through the pressurization hole. A mass flow meter measures the gas flow through the pressurization hole to determine if it is capable of supporting requisite pressurization of a nuclear fuel rod when the end plug is assembled thereto.

Nuclear fuel rod end plug pressurization hole inspection apparatus

Growing community of inventors

Wilmington, NC, United States of America

Andrew A Lingenfelter