Westinghouse Electric Corporation

Westinghouse Electric Company LLC

Wade H Widener

David A Boatwright

Kenneth K Klapper

Robert Duncan

Thomas B Huggins

An end cap is mounted on a fuel rod gripper to cover the end portions of fingers thereon to minimize impacts with grid cell dimples. The fingers are defined by circumferentially-spaced and longitudinally-extending slots in the gripper which permit the finger end portions to radially expand and retract between corresponding expanded and collapsed conditions. The end cap includes a body having a forward camming portion and a rearward mounting portion. The rearward mounting portion is hollow and configured to fit over and cover the end portions of the gripper fingers with the forward camming portion extending forwardly thereof. Also, circumferentially-spaced and longitudinally-extending attachment flutes are disposed internally of the hollow mounting portion of the body and project radially inwardly therefrom. The flutes are configured to releasably fit within the respective slots of the gripper when the finger end portions thereof are in the expanded condition and to be retained therein when the finger end portions are in the retracted condition.

Fuel rod gripper end cap for minimizing impact with grid cell dimples

An apparatus for loading cylindrical fuel pellets into tubular fuel rods includes pellet segregation means for detecting and segregating an undersized pellet prior to its entry into a fuel rod. The segregation means includes a pair of laterally separated guide rails adapted to support the lateral side edges of the advancing pellets, and such that a pellet of undersized diameter will drop to a level below that of the properly sized pellets. A lateral shoulder is positioned at the downstream end of the guide rails for engaging and holding any dropped pellet so that it cannot advance into the fuel rod. Also, a pellet deflecting plate is positioned at the upstream end of the guide rails, to interrupt the contact between adjacent pellets and thus assure that an undersized pellet is not carried along the guide rails by the adjacent pellets.

Apparatus and method for loading pellets into fuel rods

An end cap is mounted on a fuel rod gripper to cover the end portions of fingers thereon to minimize impacts with grid cell dimples. The fingers are defined by circumferentially-spaced and longitudinally-extending slots in the gripper which permit the finger end portions to radially expand and retract between corresponding expanded and collapsed conditions. The end cap includes a body having a forward camming portion and a rearward mounting portion. The rearward mounting portion is hollow and configured to fit over and cover the end portions of the gripper fingers with the forward camming portion extending forwardly thereof. Also, circumferentially-spaced and longitudinally-extending attachment flutes are dispsoed internally of the hollow mounting portion of the body and project radially inwardly therefrom. The flutes are configured to releasably fit within the respective slots of the gripper when the finger end portions thereof are in the expanded condition and to be retained therein when the finger end portions are in the retracted condition.

A nuclear fuel pellet unloading apparatus includes a transfer housing pivotally movable between an upright position remote from a pellet deposit site and an inverted position adjacent to the deposit site, and convertable between opened and closed conditions. In its upright position and closed condition, the housing receives a sintering boat loaded with nuclear fuel pellets and holds the boat while retaining the pellets within the boat as the boat is moved from upright to inverted orientations upon pivoting of the housing from its upright to inverted position. An actuator is operated for causing pivoting of the housing from its upright to inverted position and back to its upright position. A latch member latches the housing in its closed condition when the housing is disposed in its upright position and as the housing is pivoted from its upright position toward its inverted position. A release member actuates the latch member as the housing reaches its inverted position to unlatch the housing and render it capable thereafter of converting from closed to opened condition upon reverse pivoting of the housing from the inverted position back toward the upright position by operating the actuator, thereby allowing dispensing of pellets from the opened housing and open top of the boat to the pellets deposit site.

Nuclear fuel pellet sintering boat unloading apparatus and method

An inspection gage includes an expandable tubular member insertable within a fuel assembly guide thimble. The tubular member has embossments circumferentially spaced from one another about the tubular member and being the same in number as bulges on the guide thimble and configured to fit therewithin. An expansion member rotatably mounts the tubular member and is axially movable therewithin when the latter is inserted within the guide thimble. The expansion member is movable between a first position in which it permits inward contraction of the tubular member an displacement of its embossments away from the guide thimble bulges for removing the embossments from registry therewith and a second position in which it produces radial expansion of the tubular member and displacement of its embossments toward the guide thimble bulges for placing the embossments in registry therewith. A handle is used for rotating the tubular member relative to the expansion member so as to bring the embossments into alignment with the guide thimble bulges concurrently as the embossments are being displaced toward and into registry with the bulges. An indicator mechanism responses to rotation of the tublar member away from a reference position to provide an indication of the orientation of the guide thimble bulges relative to a reference point upon displacement of the embossments into registry therewith.

Nuclear fuel assembly grid sleeve/guide thimble bulge orientation gage

An improved end plug for attachment on an end of a cladding tube of a nuclear fuel rod facilitates using a gripper tool for loading the fuel rod into a nuclear fuel assembly. The end plug includes an inner portion adapted to be inserted into the end of the tube and an outer portion adapted to extend from the end of the tube when the inner portion is inserted therein. The outer plug portion has a body part disposed adjacent the tube end and a leading part disposed remote from the tube end. The leading part of the outer plug portion has a hollow interior cavity defined therein, an exterior annular truncated surface defined on a terminal end thereof and an exterior annular tapered surface defined on a lateral side thereof. The exterior tapered surface extends between and merges with the body part and the exterior truncated surface and provides sufficient angular inclination so as to facilitate insertion of the end plug when mounted on the fuel rod tube end into the fuel assembly. The interior cavity in the leading part has an inner end, an outer opening defined at and surrounded by the exterior annular truncated surface and an interior annular wall surface interconnecting the inner end and the outer opening. An undercut annular groove is defined in the interior wall surface of the cavity, has a larger diametrical size than the interior wall surface and is spaced from the cavity opening. The groove is engageable by the gripper tool when fitted through the cavity opening for loading the fuel rod into the nuclear fuel assembly. The leading part has a thickness between the exterior tapered surface thereon and the interior cavity undercut groove therein which is less than the radius of the groove and greater than the width of the exterior truncated surface, and the interior wall surface of the cavity has an axial length between the exterior truncated surface and the undercut groove which is greater than the axial width of the groove, such that the leading part is provided with sufficient wall structure laterally surrounding the interior cavity to react the forces created by engagement of the gripper tool within the cavity groove.

End plug with truncated tapered leading end configuration

An improved retention strap for maintaining a fuel assembly grid in an assembled condition during manufacture in a grid assembly fixture includes four members extendible along the respective outer grid straps, between the corners and about the periphery of the grid. Each member has a pair of end posts and a cross member extending between and connected with the end posts. The end posts of the members are disposed adjacent the respective corners of the grid when the grid is in the assembled condition. Pairs of brackets interconnect respective ones of the end posts of the members, whereas pairs of releasable connectors fasten respective others of the end posts of the members so as to form diagonally opposite pairs of substantially rigidly squared first fixed and second openable corners. Also, the retention strap includes a pair of clamps disposed at each of the fixed and openable corners formed by the end posts. The clamps are engagable with a selected one of the end portions of the outer grid straps forming the respective grid corner disposed adjacent one of the squared corners of the retention strap. The outer grid strap end portion selected is the one having a terminal edge defining the inner part of the lap joint at the grid corner. The clamps have inner hook-shaped elements which engage on the selected end portion to pull outwardly thereon and thereby pull outwardly on the other end portion of the pair thereof forming the grid corner which secures the end portions against the respective one of the squared corners of the retention strap and thereby prevents distortion of the grid corner during welding of each respective lap joint at a corner of the grid. Each clamp also has a second adjustable element adapted to bear against the retention strap member and exert an outwardly-directed pulling force on the outer grid strap end portion via the first element thereon.

Retention strap in a grid assembly fixture

A fastener locking device for attaching the lower end of a guide thimble to the upper adapter plate of a fuel assembly bottom nozzle includes a connecting fastener and an annular locking sleeve. The fastener has an elongated body portion and an enlarged head portion, and is insertable from the bottom through a passageway of the bottom nozzle. The fastener body portion is externally-threaded for forming a threaded connection with an internally-threaded plug on the lower end of the guide thimble. Also, the fastener head portion has a cross-sectional size larger than that of the fastener body portion and of a small diameter upper passageway portion but smaller than that of a large diameter lower passageway portion for defining an annular gap therebetween and bottoming against an annular ledge which divides the upper and lower passageway portions. The fastener head portion also has a annular outwardly-opening groove defined therein. The annular locking sleeve has opposite upper and lower end segments. The sleeve upper end segment is insertable into the annular gap, and has a smaller cross-sectional size than that of the fastener head portion and an annular inwardly-extending lip thereon which fits into the annular groove when the sleeve is inserted into the gap. Also, the sleeve upper end segment contains a plurality of circumferentially spaced axially-extending slots which facilitates resilient circumferential expansion of the cross-sectional size thereof for fitting it snugly about and past the fastener head portion and into frictional engagement with a knurled exterior surface on the fastener head portion and for fitting the lip on the sleeve past the fastener head portion and into the groove. The other sleeve end segment has projections which mate with recesses defined in the lower passageway portion when the sleeve is inserted into the gap.

Fastener locking device for attaching guide thimble to fuel assembly

An apparatus for repairing a protruding portion of an outer grid strap spring includes a support frame made up of interconnected members defining a generally rectangular opening and a plurality of devices mounted on the frame members above and below the frame opening for attaching the frame to the outer strap of the support grid. At least some of the devices are adjustable for securing the frame in a stationary position on the outer strap so that the frame opening is stationarily aligned with the outwardly protruding spring on the outer strap. A pair of spaced apart rails attached to the members on upper and lower sides of the opeing define a guide channel therebetween which extends along the opening in a first direction. The apparatus also includes a rectangular-shaped slide housing having a pair of spaced vertical flanges on opposite lateral sides thereof defining a passageway through the housing and a guide way extending along the passageway in a second direction generally orthogonal to the first direction. The housing is mounted in the guide channel of the frame for sliding movement along the frame opening back and forth in the first direction between lateral sides thereof for aligning the passageway with the outwardly protruding portion of the outer strap spring. Also, a spring reset mechanism is provided by the apparatus which is operable for resetting the protruding spring to a nonprotruding position relative to the outer strap when the mechanism is aligned with the protruding portion of the spring. The apparatus also has a slide block which supports the spring reset mechanism and is mounted in the guide way of the housing for sliding movement along the housing passageway back and forth in the second direction between upper and lower sides thereof for aligning the spring reset mechanism with the protruding spring portion.

Outer grid strap protruding spring repair apparatus

An orientation device for properly orienting nuclear fuel rod end plugs (18) in their proper mode for ultimate use and processing includes a funnel (12) the inside diameter (d) of which is greater than the diameter (D) of each end plug (18), and the diameter (D) of each plug (18) is greater than the length (L) of each plug. The plugs (18) are permitted to pass through the funnel bore (30), however, only when the longitudinal axis of each plug is coaxial with the longitudinal axis of the funnel bore (30) because the diagonal dimension (DG) of each plug as defined between any point on the plug's upper peripheral surface (26) and a point disposed diametrically opposite the first point upon the lower peripheral surface (28) is greater than the diameter (d) of the funnel bore. Each plug (18) also includes a large diameter portion (20) having the diametrical dimension D, and a smaller diameter portion (22), and in order to insure the ultimate proper orientation of each plug such that the smaller diameter portion (22) is disposed downwardly, the plugs (18) are pivoted 90.degree. by a deflector plate (38) and are transferred to a second re-orientation zone which includes a semicircular trough (36) and a rectangularly configured trough (42) having rails (44) defined within the sidewalls for supporting the plugs (18') in their correctly oriented vertical mode. The plugs (18') are discharged through a port (58) to a shuttle mechanism for subsequent processing.

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Cayce, SC, United States of America

Wade H Widener