Abstract: A grid assembly fixture for use in assembling grid straps to form a grid comprises a generally flat plate having first and second sets of parallel grooves, with the grooves of the sets at right angles. A retention strap comprises first and second pairs of bars, the bars of each pair hinged together adjacent their ends, and releasable joining elements for joining the pair of bars.A method of assembling the grid straps includes positioning a first set of straps in a grid assembly fixture, positioning a second set of straps at right angles to the first set to form a grid, placing outer straps on the grid, and placing a retention strap on the outer straps.

Abstract: The sleeving method comprises inserting a metal sleeve within a tube so as to bridge the defective region of the tube. The sleeve is constructed to have annular slots on the outside thereof that are capable of tightly contacting the inside surface of the defective tube and creating a labyrinth-type seal therebetween. The sleeve is also constructed to have an expander member captured therein that may be pulled through the sleeve thereby causing expansion of those portions of the sleeve having the annular slots therein. Once such a sleeve has been inserted into the defective tube, the sleeve is internally expanded in the area of the sleeve wherein the annular slots are located by pulling the expander member through the sleeve. The expansion of the sleeve in the area wherein the annular slots are located causes the lands between each annular slot to closely contact the inside surface of the tube. The other end of the sleeve can then be either similarly attached to the tube or otherwise attached to the tube.

Abstract: A welding apparatus for internally welding sleeves to tubes comprises a central shaft with an electrode attached thereto which are capable of being inserted in a tubular member. A plurality of remotely actuable seals are disposed on the welding apparatus and around the electrode for establishing a sealed chamber in the sleeve in which the welding may take place. The welding apparatus is capable of supplying an inert shielding gas to the sealed chamber for pressurizing the sealed chamber during the welding process and while the electrode completes a weld around the inner circumference of the sleeve. The apparatus may also be used to internally braze the sleeve to the tube.

Abstract: A strap and vane positioning fixture is provided for aligning simultaneously the segments of straps forming a fuel rod grid. The fixture comprises a plate having a plurality of rods extending from it, in rows and columns, positioned for entry into cells of a grid. The rods at the periphery of the plate comprise a first set and have at their upper ends a spade with a single blade, the remaining rods comprising a second set and having at their upper ends a spade with a pair of blades. A method comprising engaging vanes extending from certain straps to align segments of each strap between the slots thereof, and holding the straps in the aligned position.

Abstract: A workpiece handling assembly for gripping, manipulating and releasing a fixtured workpiece assembly for transport to and from and positioning in a workpiece welding station and the like by a hoist to minimize contamination of the welds comprising an inverted generally "U" shaped gripping and manipulating gripping device including a telescopically extensible horizontal crossbeam structure having depending support arms extending downwardly from opposite ends thereof. The lowermost ends of said arms have pivoted gripper jaw members journaled therein for rotary movement about a common horizontal axis, including foot formations shaped to interfit and grip convergent grip edges of triangular protrusions projecting from the workpiece. The gripper jaw members are movable to and from gripping relation with the triangular protrusions, and the gripper jaw members can be latched at diametrically opposite angular positions to support the workpiece in either of two relatively inverted positions.

Abstract: The fuel assembly skeleton compaction system provides a means for remotely dismantling an irradiated nuclear fuel assembly skeleton once the nuclear fuel rods have been removed therefrom while the skeleton remains submerged in a coolant. The system comprises a feed chamber for holding the spent fuel assembly skeleton and for feeding a spent fuel assembly skeleton into a shear chamber which is arranged near the feed chamber. The shear chamber contains a shearing device for shearing the skeleton into small pieces and for moving the pieces of the skeleton into a compaction chamber which is located adjacent to the shear chamber. The compaction chamber contains a compaction cylinder for compacting the pieces of the skeleton introduced thereinto. A storage canister is located below the compaction chamber such that when the slide of the compaction chamber is opened, the compacted pieces of the skeleton may be pushed into the storage canister.

Abstract: A grid assembly fixture for use in assembling grid straps to form a grid comprises a generally flat plate having first and second sets of parallel grooves, with the grooves of the sets at right angles. A retention strap comprises first and second pairs of bars, the bars of each pair hinged together adjacent their ends, and releasable joining elements for joining the pair of bars.

Abstract: Apparatus is disclosed for laser machining a work piece comprising a laser lens adapted to be releasably mounted to permit cleaning of the lens to remove any debris collected thereon during laser machining. The mounting includes a cylindrical base for defining a path along which the laser beam emitted by the laser source is directed onto the work piece, and a mounting member for mounting the laser lens with respect to the cylindrical base and adapted to be removably mounted on the cylindrical base in a manner whereby the lens is disposed to a certain position with respect to the cylindrical base. To this end, there is included a locking member engaging the cylindrical base and biasing the mounting member and its laser lens to the certain position with respect to the cylindrical base.

Abstract: A welding apparatus for internally welding sleeves to tubes comprises a central shaft with an electrode attached thereto which are capable of being inserted in a tubular member. A plurality of remotely actuable seals are disposed on the welding apparatus and around the electrode for establishing a sealed chamber in the sleeve in which the welding may take place. The welding apparatus is capable of supplying an inert shielding gas to the sealed chamber for pressurizing the sealed chamber during the welding process and while the electrode completes a weld around the inner circumference of the sleeve. The apparatus may also be used to internally braze the sleeve to the tube.

Abstract: A robotic manipulator wrist has one part 10 rotatable relative to the other part 12 of the wrist, and gear trains 16, 18, 20, operates to rotate the end effector shaft 14 when a brake 36 is applied to prevent relative movement between the two parts 10 and 12, and to rotate one part 10 relative to the other part 12 when a second brake 38 is applied to prevent relative movement between the end effector gear 18 and the intermediate gear 16.

Abstract: Welding plates for laser beam welding of a fuel rod grid are provided, each welding plate having a surface with a set of equally spaced, parallel grooves and with a second set of such grooves perpendicular to the first set. Each of the welding plates is provided with openings therethrough at the points of intersection of the straps forming the grid, so as to expose those points of intersection to a laser beam for laser beam welding of the points of intersection. A vane side welding plate has the walls of the laser beam access openings placed so as to hold vanes extending from the straps in deflected position. Stand-off pins and clamping bolts are provided, the latter having heads with access openings for the laser beam. The welding plates are provided with protrusions which extend laterally thereof, the protrusions having precisely located holes with precision bushings therein.

Abstract: Apparatus for decontaminating radioactive components comprising an attachment mechanism for completely suspending the apparatus from the tube sheet of a nuclear steam generator, a first drive mechanism for moving the apparatus in a first direction, a second drive mechanism for pivoting the apparatus in a second direction, and a third drive mechanism for moving the apparatus in a third independent direction. The apparatus also comprises a dual nozzle arrangement attached to the third drive mechanism for directing a water-grit mixture toward the component to be decontaminated. The apparatus provides a mechanism for remotely decontaminating the channel head of a nuclear steam generator so as to allow working personnel to enter therein.