Abstract: A laser profiler is mounted to the focusing head for a laser welding beam to generate profile data for successive transverse viewing planes of an elongated joint prior to their presentations to the welding beam. The profile data is computer processed in accordance with a joint extraction algorithm using parameters defined in a tracking schedule characterizing the geometry of the joint to calculate the location of the joint centerline. The centerline location data is computer processed in accordance with a tracking algorithm to generate signals for activating a positioning head to adjust the position of the welding beam focal point and thus to track the moving joint as seam welding is effected.

Abstract: An apparatus and process for the construction of a cruciformed section control rod is disclosed. The control rod is characterized by having square exterior sectioned tubes with central cylindrical volumes for the containment of neutron absorbing poisons. In the process, these tubes are welded together at the corners of the square sections to form the planar members of the cruciformed shaped rods. An apparatus and process is disclosed in which the rods are all held by a jig in the same configuration as is ultimately fabricated. Thereafter, the jig is drawn through fixtures, which fixtures accurately guide the rods to be joined by welding past paired and opposed laser welding heads. By the expedient of positioning the laser and rapidly drawing the braced together tubes by the laser, control rod fabrication occurs. There results a solid, integral control rod constituting a suitable pressure vessel for neutron absorbers for control of nuclear reactions.

Abstract: An apparatus and process for the construction of a cruciformed section control rod is disclosed. The control rod is characterized by having square exterior sectioned tubes with central cylindrical volumes for the containment of neutron absorbing poisons. In the process, these tubes are welded together at the corners of the square sections to form the planar members of the cruciformed shaped rods. An apparatus and process is disclosed in which the rods are all held by a jig in the same configuration as is ultimately fabricated. Thereafter, the jig is drawn through fixtures, which fixtures accurately guide the rods to be joined by welding past paired and opposed laser welding heads. By the expedient of positioning the laser and rapidly drawing the braced together tubes by the laser, control rod fabrication occurs. There results a solid, integral control rod constituting a suitable pressure vessel for neutron absorbers for control of nuclear reactions.

Abstract: In a control rod construction for moderating and controlling a reaction of a nuclear reactor, a control rod structure is disclosed in which hafnium is welded to stainless steel. Typically, the control rod is confined for movement axially along its length into and out of the reactor. The hafnium is surrounded in the control rod structure by a sheath of stainless steel to inhibit movement relative to the control rod structure other than in the axial direction of control rod movement. The hafnium is friction welded to the stainless steel of the control rod so as to stress the weld in either tension or compression due to dynamic loading occurring from control rod movement. The stainless steel to which the hafnium is welded is in turn conventionally welded or mechanically connected to the remaining steel components of the control rod.