Abstract: A water rod for a fuel assembly of a boiling water nuclear reactor has a first end and a second end, wherein at least one of the first and second ends is directly attachable to a tie plate of the fuel assembly without an end plug. The structure of the present invention simplifies the manufacturing process and reduces the cost of the fuel assembly in the boiling water nuclear reactor. The water rod according to the invention has one or both of its ends configured to be directly attachable to the tie plate of the fuel assembly.

Abstract: A support rod 14 carrying one or more separation devices 12, e.g., swirlers, is releasably secured in a fuel bundle. The support rod and separation devices are sized to pass through openings in the spacers S otherwise containing full length fuel rods. The lower end of the support rod is releasably connected to the upper end of a part-length fuel rod PLR which in turn is releasably connected to the lower tie plate. The support rod, separation devices and part-length rod may be installed and removed relative to the fuel bundle as an integral assembly with the part-length rod and separation devices passing through the openings in the spacers. When installed, the separation devices lie above upper spacers in the vent volumes to flow liquid on and into the interstices of the surrounding fuel rods.

Abstract: The static pressure within an air-supported structure is monitored and controlled in accordance with monitored environmental conditions. The static pressure is kept at the minimum value required to maintain the structures's integrity, thereby using a minimum amount of energy. As outside wind velocity incrementally increases, the static pressure is increased incrementally. Under certain weather conditions such as high winds and frozen precipitation, the static pressure is increased to a maximum limit. As a safety feature, a secondary inflation device is activated to assist a primary inflation device to quickly increase pressure in the structure in response to a sudden loss in pressure.

Abstract: 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.

Abstract: In a fuel bundle for a boiling water nuclear reactor comprising a plurality of fuel rods secured within an array and extending between upper and lower tie plates, and including at least one additional fuel rod extending from the lower tie plate but terminating short of the upper tie plate, an improvement wherein a removable extension rod secured to the at least one additional fuel rod and extending substantially to the upper tie plate. The removable extension rod is in the form of a hollow tube having a plurality of openings therein and an internal flow path over an axial portion of the hollow tube, the flow path serving to cause coolant in the hollow tube to be deposited on adjacent fuel rods.

Abstract: An extraction tool for removing a partial length fuel rod from a fuel bundle assembly, wherein the partial length fuel rod has an upper end plug, the tool comprising an extension rod having a pair of gripper jaws mounted at one end thereof, the gripper jaws shaped and sized to engage the upper end plug; and a locking tube slidably received over the extension rod and engageable with the gripper jaws to lock the gripper jaws to the upper end plug.

Abstract: The spacer comprises a plurality of strips interleaved with one another to form an eggcrate-type pattern defining essentially rectilinear cells for each fuel rod. Each strip includes a central body portion with cantilevered loop spring-like projections extending to opposite sides, with spring contact portions projecting inwardly. Stops are provided along each of the central body regions of the strips intermediate the loop springs that project to the opposite side of the strip. Adjoining walls have loop spring portions for biasing the rod into engagement with opposing stops whereby each fuel rod is supported at six contact points, i.e., four spring contact points and two hard stop contacts opposite the paired spring contacts.

Abstract: A fuel bundle for a nuclear reactor includes a plurality of fuel rods extending between upper and lower tie plates, and a filter plate seated on the lower tie plate. The filter plate includes a substantially planar plate having a plurality of fuel rod holes in a predetermined array, the plate having web areas between the fuel rod holes which are formed with a plurality of smaller debris filter holes. At least one of the web areas is formed to include a spring tab pivotable out of the plane of the plate so that in the event of debris overload, coolant can bypass the smaller debris filter holes.

Abstract: The spacer for a nuclear fuel bundle includes unit cells having upper and lower, generally octagonally shaped walls connected one to the other by spring leg portions along sides thereof 90.degree. apart. The walls also carry stops in opposition to the sides of the walls to which the spring leg portions are connected. By orienting the cells in the spacer such that the majority of the cells have their stops lying toward one side of the spacer, the fuel bundle can be disposed in a horizontal position on the one side of the spacers. In that manner, the dead load of the fuel rods and spacers is borne by the stops along the underside of each spacer without substantially loading the springs of the spacer cells.

Abstract: In a nuclear reactor fuel bundle assembly having a plurality of fuel rods and a non-round water rod extending between upper and lower tie plates, and having at least one fuel rod spacer located along the non-round water rod, an improvement which includes cooperating components on the fuel rod spacer and on the water rod for permitting movement of the spacer along the water rod to a desired axial location and for thereafter preventing further axial movement of the spacer in at least one of two opposite axial directions, the cooperating components including at least one spring on one of the spacer and the water rod.

Abstract: The static pressure within an air-supported structure is monitored and controlled in accordance with monitored environmental conditions. The static pressure is kept at the minimum value required to maintain the structure's integrity, thereby using a minimum amount of energy. As outside wind velocity incrementally increases, the static pressure is increased incrementally. Under certain weather conditions such as high winds and frozen precipitation, the static pressure is increased to a maximum limit. As a safety feature, a secondary inflation device is activated to assist a primary inflation device to quickly increase pressure in the structure in response to a sudden loss in pressure.

Abstract: A spacer for retaining nuclear fuel rods in laterally spaced relation to one another includes first and second sets of spacer strips extending in mutually perpendicular diagonal directions relative to a generally rectilinear peripheral spacer band. The strips have linearly extending sections with adjacent sections angularly related to one another and meeting at apices. The sections of each strip alternately intersect a diagonal line across the spacer with the apices alternately located on opposite sides of the diagonal line. Alternate apices have springs projecting to one side of the strip for engaging fuel rods and apices between the alternate apices have stops projecting on opposite sides of the strip for engaging the fuel rods. Slots are provided in the strips enabling intermeshing of the strips with one another to define discrete cells peripherally encompassing and retaining fuel rods within the spacer.

Abstract: In a boiling water reactor fuel bundle, a three dimensional debris catching grid construction is placed within the flow volume defined by the lower tie plate assembly between the inlet nozzle and upper fuel rod supporting grid. A perforated plate is utilized having round holes as small consistent with the prevention of inadvertent closure due crudding and a hole pitch consistent with mechanical integrity requirements. The perforated plate is placed in a three dimensional construction such as a dome, cylinder, pyramid, inverted pyramid or corrugated construction spanning the flow volume of the lower tie plate assembly. As a consequence of this three dimensional grid construction, the total flow through area of the perforations in the metal plate does not introduce appreciable pressure drop in the lower tie plate assembly between the inlet nozzle and the rod supporting grid.

Abstract: A fuel bundle assembly for a nuclear reactor, wherein a plurality of fuel rods and at least one water rod extend between an upper tie plate and a lower tie plate, includes upper end plugs secured to a pair of water rods and having axial cut-out portions defined by upper and lower shoulders. A latching mechanism for securing the pair of water rods to the upper tie plate includes a latch bar mounted on an upper surface of the upper tie plate and rotatable into and out of the cut-out portions in the end plugs when the end plugs extend above the upper surface of the tie plate upon installation of the upper tie plate on the fuel bundle assembly. A locking pin is provided which prevents the latch bar from being accidentally unlocked.

Abstract: A grapple is provided for use with a fuel bundle channel of a nuclear reactor wherein the channel is provided with a pair of gussets in opposite corners of an upper end of the channel, each gusset having a hole therein. The grapple includes a pair of lever arms, each provided with a lifting foot at a lower end of the respective lever arm. The lever arms are movable in opposite directions to a channel lifting position wherein the channel gripper of each lever arm is located under a respective one of the pair of channel gussets. The channel lifting foot of each lever arm includes a pair of laterally spaced lifting elements such that the lifting feet may engage the underside of the gusset on either side of the gusset hole. In addition, each channel lifting foot includes a secondary foot or slider captured between the pair of lifting elements.

Abstract: An apparatus for loading nuclear fuel rods through spacer grid cells of a fuel bundle includes a handle having at least one elongate clip joined thereto, and a flexible tubular sleeve joined to the clip. The clip rigidly supports the sleeve along its longitudinal axis while allowing the sleeve to unfurl perpendicularly thereto for disassembly from a fuel rod. In several embodiments of the invention, the clip may include a slot for bridging adjacent grid cells during assembly, or the clip may be removably fixedly joined to the handle for allowing easy replacement of the sleeves.

Abstract: In a boiling water reactor fuel bundle, a three dimensional debris catching grid construction is placed within the flow volume defined by the lower tie plate assembly between the inlet nozzle and upper fuel rod supporting grid. A perforated plate is utilized having round holes as small consistent with the prevention of inadvertent closure due crudding and a hole pitch consistent with mechanical integrity requirements. The perforated plate is placed in a three dimensional construction such as a dome, cylinder, pyramid, inverted pyramid or corrugated construction spanning the flow volume of the lower tie plate assembly. As a consequence of this three dimensional grid construction, the total flow through area of the perforations in the metal plate does not introduce appreciable pressure drop in the lower tie plate assembly between the inlet nozzle and the rod supporting grid.

Abstract: A method and apparatus measure squareness of an end of a rod relative to a longitudinal centerline axis thereof without requiring rotation of the rod. The apparatus includes a flat plate mounted substantially perpendicularly to the rod centerline axis. The method positions the plate in abutting contact with the rod end, and a tilt angle of the plate in abutting contact with the rod end is measured for determining squareness of the rod end.

Abstract: A plenum spring and getter assembly for use in a nuclear fuel rod has a plenum spring design which retains the getter at a desired distance from the fuel column. The plenum spring is a wire having a first wound section of diameter greater than the diameter of the getter installed therein, a second wound section of diameter less than the getter diameter and a third wound section having a diameter which is preferably, but not necessarily, equal to the diameter of the first wound section. The wound sections are connected in series along an axis, with the "necked" second wound section being situated intermediate the first and third wound sections. When the fuel rod in accordance with the invention is installed upright in the reactor, the getter bears against and is supported by the first turn of the necked wound wire section.

Abstract: A fuel pellet retainer spring assembly is disclosed for insertion to the open unsealed end of a fuel rod. The assembly includes a locking sleeve having a normal radial diameter exceeding the inside radial diameter of the fuel rod cladding. This sleeve is compressed to a diameter less than the inside diameter of the fuel rod cladding. Thereafter, the sleeve is inserted. In the preferred embodiment, a washer and coil spring precedes the sleeve into the fuel rod. The sleeve is inserted and thereafter allowed to expand and frictionally hold to the inside wall of the cladding. When the sleeve is in place, the coil bears against the inside portion of the radial sleeve and forms the surface from which a fuel pellet biasing spring maintains fuel pellets within the unsealed fuel rod.