Abstract: A fuel rod capturing support grid having a spring and arch design which provides performance improvements over current or previous designs by decreasing fuel rod fretting wear. The disclosed spring and arch designs follow the contour of the fuel rod, thus providing an increased, substantially arc-shaped area of contact between the fuel rod and the spring tabs and arches.

Abstract: A fuel element (10) for a nuclear reactor having a zirconium-tin alloy cladding tube (20), with a thin coating (30) of a burnable poison consisting of an enriched boron particles sealed in a boron-containing glass or glass compound deposited from a liquid sol-gel.

Abstract: Helical isolator (I.sup.1, I.sup.2) in a turnbuckle frame (10) on a central rod (2) with connector rods (34, 36) of opposite handed threads, are for mounting between a pipe and an adjacent structure. The wire energy absorbing rope bights (32) of the isolator I.sup.1, I.sup.2 are placed in parallel planes and in a state of precompression and have bi-linear spring properties which are adjustably provided by the diameter of the structural tube (10) and spacer bars (30) attached to the tube wall (12) as part of the bases (26, 28) of the isolators.

Abstract: The displacement of a valve stem (16) is measured during diagnostic testing by temporarily mounting a laser head (112) on the valve body (18) or yoke (20), for generating a source laser beam (118) that reflects from a target (120) that moves with the stem. The timing of the reflected beam (132) returning to the head (112) relative to the projection of the source beam, gives an indication of the displacement of the stem.

Abstract: A method of removing in-core instruments and dry tubes from a boiling water reactor during a refueling outage wherein a pair of temporary storage containers are provided in the reactor core. A remotely operated cutting device is superposed on the first temporary storage container. An instrument is suspended by an end, with the in-core part uppermost, and lowered until a portion of the out-of-core part is within the first temporary storage container. The cutting device is then operated to sever the instrument portion within the temporary storage container. The instrument is repeatedly lowered, and portions severed, until all of the out-of-core part of the instrument is in the first temporary container. The in-core part of the instrument is then lowered into the second temporary container and the two temporary containers are removed from the reactor cavity using the existing equipment-handling crane.

Abstract: An electron discharge machining tool (10) for removal of conductive material from a workpiece such as a plug (28) in a nuclear steam generator tube (26) is an end effector connected to a remotely operated manipulator arm by a mount (56). A piston (47) drives a hollow conductive rod (44) with a graphite electrode cutter (30) in reciprocating motion through receptacle (14) having a restrictive drain (37) and containing deionized water. The reciprocation of rod (44) is controlled by power supply (50) sensing the electrical potential and signalling valve (48) which controls hydraulic flow in conduits (54a, 54b) communicated to opposite sides of the piston (47). A TV camera (32) and a light (34) mounted behind a lens (36) are used to monitor the machining.

Abstract: An apparatus for monitoring the position of the shaft of a coolant circulating pump of a nuclear steam generating system comprising light source for directing a light beam at a number of reflecting surfaces on the shaft and a pair of spaced apart light receiving devices adapted to receive light beams reflected off the reflecting surface. Light from the receiving devices is conveyed, by fiber optic cables, to intensity measuring devices which measure the intensity of the two light beams on a time-dependent basis. A processor calculates the shaft rotational speed and the magnitude of the shaft wobble as functions of the time-dependent intensity measurements of the pair of reflected light beams.

Abstract: A method of repairing a nuclear power facility metal component assembly with a "Class A" fastening between hard metal parts (12,14) includes several steps they are:providing aligned openings (20,22) in a plurality of hard metal parts (12,14) to be assembled;EDM machining a non-cylindrically shaped cavity (16) which is analogous to a counterbore having a cavity opening (24) smaller than the cavity base (18);inserting a locking collar (10) with a central aperture (32) and surrounding flange (3) to receive a bolt head (42) and with weakened zones of deformation (34) through the cavity opening (24);inserting a headed and threaded bolt (40) through the central aperture (32) of the locking collar (10) and into the aligned bores (20,22);providing threads (46a) in another of the hard metal parts to mate the bolt threads (46);torquing the bolt (40) in the provided mating threads (46a) to draw the bolt head (42) toward the cavity base (18) and deforming the locking collar at its weakened zones of deformation (34) to ca

Abstract: A removable and reusable cap for fuel rod ends to prevent grid damage during loading permits fuel end configurations to match utility's special tooling for fuel assembly repair and reconstitution. The elastomeric transitory fuel rod guidance ends expand over a flange and temporarily snap into place in a groove in the fuel rod end to provide a tapered guiding surface.

Abstract: A watertight cover for the hook, hook block and cables of a crane comprises a hook box, of a size to receive the hook, fixed to a first cover member, which is of a size to receive the hook block. A second cover member is telescopically carried on the first cover member. Remotely controlled means are provided for displacing the second cover, relative to the first cover, as the hook is lowered into the water.

Abstract: A method of remotely installing or removing and assembling and disassembling nozzle dams (10) from outside a steam generator manway (14) using a tool set. The tools are a bifurcated segment lifting (torquing and push-pull) tool 60 to unweight and faciltate the operation of sliding dam segments (30,32) edgewise along sliding brackets (40) and bars (44) in an assembly and disassembly operation; a cam-lock component (36) operating T-shaped tool (80) with a nozzle dam rib avoiding offset (88), transverse quick-connect body (50b) straddling tool (90) pull a sleeve (50c) in order to disassembly quick-connects; and, a gasket installing, tensioning and removing hook tool (102).

Abstract: A coupler body 12 with a socket 44 therein is attached to nuclear stream generator tools to be mated with an arm 22 of a remotely controlled manipulator. A plug 16 for insertion in socket 44 is mounted with a ball detent lock actuating air cylinder 18 on L-shaped bracket 20 attached to the end of arm 22. Cam surfaces 62 on body 12 and 64 on bracket 20 align the plug 16 and socket 44 for insertion to mate and couple the tools and arm 22.

Abstract: Bottom end fuel assembly reconstitution is permitted by elimination of weld of Inconel lower grid perimeter strip to stainless steel lower end fitting. Slots in 2 or 3 sides of L.E. Fitting capture ribbed sections of grid perimeter strip, locking screws hold L.E. Fitting in position on guide thimbles. Grids lip on perimeter strip is interlocked by sliding in L.E. Fitting groove.

Abstract: A tool for axially removing a defect-containing length portion from a steam generator tubesheet primary side grips the tube length portion on both sides of the defect by radially outwardly moving gripper structure in the form of expanding ferrules (16,20) or collet spring fingers (60). Structure in the form of a central mandrel member (12, 13 or 50, 52, 54) moves axially to actuate the gripper structure. A sleeve (62) separately actuated on the mandrel (50) assists this action in the collet spring finger (60) embodiment. Movement of the defect-containing length portion requires an initial cutting of the tube-to-tubesheet weld, and for convenience, separation of the tube length portion from the remainder of the tube. Hydraulic structure (32, 56, 64) provides the motion axially of the grippers' actuators (14, 22, 23 or 58, 66) on either side of the defect either independently or together.

Abstract: A watertight cover for the hook of a crane comprises a cylindrical rod interposed between the hook and the load. A circular seal, slidingly carried on the rod, engages an imperforate cover member telescoped over the rod and the hook. A device is provided for drawing the seal and cover member toward the hook as the hook is lowered into the water.

Abstract: An improved lower end fitting (L.E.F.) having a bell mouth type of flow jet diffuser decrease pressure drop 10-15%, more evenly distributes flow and adds strength. It includes neutron thimble flux impingement shield of instrument and/or cable. Diffusers are stainless steel of circular cross-sect. and parabolic to optimize diffusion. Shape is based on lower core plate flow hole geometry, L.E.F. design and reactor flow rate. Thinner L.E.F. legs, smaller L.E.F. gussets and thinner L.E.F. flow plates possible.

Abstract: A nuclear steam generator 10 with economizer 32 adjacent secondary side feedwater inlets 38a and 38b includes a secondary side divider plate 36 and handholes 40 at opposing 180.degree. locations in alignment with the ends of the plate 36. Notches 42 in the ends of the plate 36 adjacent the aligned handholes 40 facilitate inspection and maintenance access on the secondary side above tubesheet 22. To prevent bypass flow from one side of the divider plate 36 to the other, a novel flow blocker 50 of cylindrical shape is provided for mounting in handholes 40 and notches 42. The flow blocker 50 is defined by telescopically assembled member 52 and 62 which are biased in opposite directions by pre-loaded spring 64 therein to insure stability against vibration and flow induced loads. The flow blocker 50 fits sungly in notch 42 and handhole 40 and is bolted to the inside of closure plate 74 of handhole 40.

Abstract: A permanent pool seal and neutron shield 30 for providing an effective water barrier over the annular space 28 between a nuclear reactor vessel flange 24 and a surrounding annular ledge 22 includes annular deck sections 32 supported on spaced ribs 46.Flexible membranes 50,52 on the deck section peripheries accommodate relative movement. Openings 42, each with a removable plug structure which includes cover 44 and tapered can 60, provide vessel cavity 14 with ventilation and maintenance access. All cans 60 and similar containers 56 and 59 under the deck structure and flange 24 contain a shielding material 58 in the form of a boron-containing concrete. Supported below the cans is refractory insulating material 54.

Abstract: A method of nondestructively identifying regions "R" of high density in a substrate (10) of a bonded matrix of carbon fibers by resistively heating the substrate and taking an infrared image of the heated substrate. Terminals 12, 14, 16 and 18 are connected to a power supply 26 by wires 22 and cable 24 of which they are a part, to effect the heating.

Abstract: A frame 10 with downwardly projecting members 52 mounts by means of a pair of hoists 36 and lifting bracket 42 downwardly into upwardly open recesses of complementary mounting members 54 secured to reactor head lifting legs 30. Frame 10 is mounted on the head either with lead wool shielding blankets 40 hanging from it or without. In the latter case, hangers 60 with blankets 40 hanging therefrom and horizontally gravity biased hooks 64 mounted on a curved beam 62, are lowered by hoist 36 until hooks 64 grapple, pivot and hang hanger 60 and the shielding on frame 10 at a location radially inwardly of the head bolt locations 22. The hook of hoist 36 is lowered until it is disengaged from the radially outwardly biased bail 70 of hanger 60.