Abstract: The present invention provides a grab bar for bathing vessels. The grab bar has a substantially sinusoidal shape in the horizontal (X) and vertical (Y) coordinates, and is twisted approximately 90.degree. in the (Z) coordinate. In a preferred embodiment, the grab bar is mounted at one end to the deck of the bathing vessel, and the other end which is oriented at approximately a 90.degree. angle is mounted to the interior vertical wall of the bathing vessel. In alternate embodiment, the grab bar may be mounted on any two walls which are substantially perpendicular to each other on the bathing vessel to provide a range of angles at which the bather may hold onto and support himself relative to the walls of the bathing vessel and the grab bar.

Abstract: A typical embodiment of the invention combines a novel cellular end fitting for a nuclear reactor fuel assembly with a new design for a fuel rod end cap and a radiation sensing device probe to provide a means for swiftly and accurately distinguishing sound fuel rods from those rods that have developed leaks. For example, a somewhat thinner than usual fuel rod end cap is accessible through the open cellular structure of the end fitting to permit a hollow metal probe to contact the fuel rod end cap. This direct contact excludes most of the water, metal and other shielding materials from the volume between the interior of the fuel rod and the radiation detector, thereby improving the quality of the fuel rod examination. A bridge and trolley structure for accurately positioning the probe also is described.

Abstract: An illustrative embodiment of the invention has a group of three concentrically disposed banks of helical steam generator tubes. Shrouds interposed between each of these three tube banks establish liquid barriers between the individual banks that prevent liquid sodium (or other shell side working fluid) from enjoying free communication throughout all of the tube banks. In this way, potentially damaging leakage between the shell side working fluid and the water within one of the tube banks can be isolated through discontinuation of the shell side working fluid and feedwater flow to the leaking bank, thereby permitting the remaining sound tube banks to continue functioning.

Abstract: A typical embodiment of the invention provides a fitting for stabilizing the burnable poison rods and the like within a nuclear reactor fuel element. An illustrative orifice rod assembly fitting is assembled inexpensively from stamped metal strips which expose the ends of the fuel rods within the fuel element for inspection and simplify rearrangement of partially used fuel elements within a reactor core.

Abstract: A typical embodiment of the invention has an array of sockets that are welded to the intersections of the plates that form the upper and lower end fittings of a nuclear reactor fuel element. The sockets, which are generally cylindrical in shape, are oriented in directions that enable the longitudinal axes of the sockets to align with the longitudinal axes of the fuel rods that are received in the respective sockets. Detents impressed in the surfaces of the sockets engage mating grooves that are formed in the ends of the fuel rods to provide for the structural integrity of the fuel element.

Abstract: An illustrative embodiment of the invention converts a feed solution stream into three separate streams of concentrated acid, concentrated alkali and deionized liquid, respectively, through a combination of ion exchange and electrodialysis techniques. Typically, feed fluid from the primary coolant loop of a nuclear reactor that contains ionized boric acid and lithium -7 hydroxide flows into a bed of mixed anion and cation exchange resins. Two of the walls of this bed, however, are of anion permeable and cation permeable membranes respectively, to permit the anions to migrate into an anolyte compartment and to permit the cations to migrate into a catholyte compartment. Within the anolyte compartment there is an anion resin bed which purifies the borate ions from other contaminative anions. Within the catholyte compartment there is a cation resin bed which purifies the lithium ions from other contaminative cations.

Abstract: In accordance with an embodiment of the invention, an array of apertured flat plates support the tubes in a heat exchanger. Each aperture has at least three bights that provide individual fluid passageways when the associated tube is lodged in place. At least three inwardly protruding members that separate the bights restrain tube movement. Each of these members define arcs of a circle that has a diameter which is only slightly larger than the outside diameter of the respective tube. During heat exchanger assembly, this slightly larger diameter of the circle defined by the inwardly protruding members accommodates departures in the tubing from a perfectly straight condition. In operation, the individual tubes will tend to lay against one or two of the members in each aperture in almost line contact to prevent "crevice corrosion.

Abstract: A typical embodiment of the invention detects leaking fuel rods by means of a radiation detector that measures the concentration of xenon-133 (Xe.sup.133) within each individual rod. A collimated detector that provides signals related to the energy of incident radiation is aligned with one of the ends of a fuel rod. A statistically significant sample of the gamma radiation (.gamma.-rays) that characterize Xe.sup.133 is accumulated through the detector. The data so accumulated indicates the presence of a concentration of Xe.sup.133 appropriate to a sound fuel rod, or a significantly different concentration that reflects a leaking fuel rod.BACKGROUND OF THE INVENTION1. Field of the InventionThis invention relates to inspection techniques, and more particularly, to a radiation detection method and apparatus for identifying leaking fuel rods within a nuclear reactor core, and the like.2.

Abstract: A self contained nut assembly to allow self nut locking and unlocking for use with a support member. The nut assembly comprises an upper nut containing a pronged locking sleeve. The nut and locking sleeve fit onto a threaded element projecting through a support member. The prongs of the locking sleeve are fashioned with feet for engagement with the support member to restrain selective movement therebetween. Arcuate portions of the sleeve are flared to fill openings in the nut thus locking the assembly in place.

Abstract: The invention pertains to a device for accepting axial forces generated during the operation of a nuclear reactor by the flow of the cooling medium and the thermal expansion of the fuel assemblies consisting of rod-shaped fuel rods while the fuel assemblies are resting on a lower grid plate and at the upper end are elastically supported against an upper grid plate.

Abstract: A typical embodiment of the invention provides a means for restraining the fuel elements within a nuclear reactor core from movement during reactor operation. Illustratively, within one of the fuel element end fittings a rectangular grid of torsion bars is positioned with the ends of each of the bars anchored in opposing parallel sides of the end fitting. Individual torsion arms fastened to the midportion of each of the respective torsion bars protrude above the end fitting to bear against the adjacent grid pads and thereby restrain motion in the direction of coolant flow. In the opposite fuel element end fitting a tube that extends through the length of the fuel element is connected to the center of a convex spring. The two ends of the spring are hinged to respective locking bars that are cammed to move in a direction that is transverse to the axis of the tube. As the fuel element moves in the direction of coolant flow, the tube presses the convex spring flat.

Abstract: A typical embodiment of the invention is a steam drying device that has a frame with two recessed slipways spaced from each other. A first array of longitudinally disposed bars within the frame are spaced transversely from each other. The ends of the bars in this first array, moreover, are received within respective slipway recesses. There also is a second array of longitudinal bars, the ends of which are received in respective slipways, the bars in both arrays being transversely spaced from each other to enable the bars to remove water droplets from the steam.

Abstract: An illustrative embodiment of the invention is directed to a thermally insulated exhaust duct structure. In this regard, a typical duct comprises an inner stainless steel conduit and one or more sheets of highly-reflective material that are spirally wrapped around and spaced outwardly from the outer surface of the conduit. The adjacent layers of the sheet material, moreover, are spaced from each other a predetermined distance through corrugated strips that are fastened to one side of the sheet material. Thus, when wound about the conduit in an overlaying relationship, the corrugation peaks bear against the sheet of material that is immediately below and thereby estabish a spacing between adjacent layers that is at least equal to the depth of the corrugations. Other features of the inventon include an outer protective stainless steel casing that fits over the spirally wrapped insulating sheet and a roof penetration for the duct structure.

Abstract: A pulsed flow process for the reduction of UF.sub.6 where the process may be continuous or batch starting without a seed bed. The initial amplitude and frequency of the pulsed flow is altered as a bed of particle-form material is formed and thereafter the particle-form product of the reaction is removed from the reaction zone.

Abstract: A typical embodiment has an end fitting for a nuclear reactor fuel element that is joined to the control rod guide tubes by means of a nut plate assembly. The nut plate assembly has an array of nuts, each engaging the respective threaded end of the control rod guide tubes. The nuts, moreover, are retained on the plate during handling and before fuel element assembly by means of hollow cylindrical locking cups that are brazed to the plate and loosely circumscribe the individual enclosed nuts. After the nuts are threaded onto the respective guide tube ends, the locking cups are partially deformed to prevent one or more of the nuts from working loose during reactor operation. The locking cups also prevent loose or broken end fitting parts from becoming entrained in the reactor coolant.

Abstract: Illustrative embodiments of the invention disclose fuel pellets for nuclear reactors in which the pellets have a controlled and relatively homogeneous porosity that accommodates fuel swelling and permits fission gases to escape from these pellets. Typically, small low density spheres, that may be formed from highly volatile material, are blended with a nuclear fuel powder, and are pressed and sintered into pellets of appropriately low density to produce an improved product.

Abstract: Typical embodiments of the invention can be used for photon generation, plasma containment or for atmospheric and/or space vehicle propulsion. Illustratively, a large dome of insulating material supports an array of smaller insulating domes. Conducting electrodes that are embedded in the external surfaces of these smaller domes are coupled to a high frequency alternating current. The electrical potential on these electrodes produces ionization in the medium external to the dome array. The ions, charged with a potential that is the same as electrode voltage, are repelled from the dome array in a preferred direction. This action establishes a resultant force that can be used to drive the array through the medium in a direction opposite to that of the ions. The ionization phenomena produced in accordance with the described technique also generates abundant photons.

Abstract: A typical embodiment of the resinous foam sandwich construction that characterizes the invention has face sheets of fiber reinforced thermoplastic resin laminates. The foam core is a mixture of hollow glass spheres and resin, in which the resin in the core is the same as the resin used to form the face sheets.

Abstract: A typical embodiment of the invention provides a structural support for large pressure vessels. Illustratively, the lower surface of a forging on the bottom of the pressure vessel has a keyway slot. A support plate with a mating key that is received within the slot is bolted to the bottom forging. The lower surface of the support plate, moreover, has an arcuate surface that presses against a matching lubricated surface to transmit the entire vertical load to a concrete pedestal that has a means for cooling the concrete structure.