Abstract: A nuclear fuel element and a method for making the fuel element are described. The fuel element comprises a graphite block in which elongated holes are filled with nuclear fuel. The nuclear fuel in each of the holes comprises a plurality of fuel rod segments which are, before firing, spaced from each other by a plurality of spacers. Upon firing, the spacer material gasifies, leaving unfilled gaps between the fuel rod segments.

Abstract: Methods and Apparatus for separation of uranium isotopes by selective isotopic excitation of photochemically reactive uranyl salt source material at cryogenic temperatures, followed by chemical separation of selectively photochemically reduced U.sup.+4 thereby produced from remaining uranyl source material.

Abstract: In a high temperature furnace adapted for fuel particle coating applications, an electrode ring forms a portion of the furnace wall, heating elements within the furnace being urged into conductive engagement with an internal surface of the electrode ring by means of adjustable spring mechanisms arranged outside the furnace and interconnected with the heating elements by elongated bolts in order to permit adjustment of the spring load without interrupting operation of the furnace. The spring mechanism provides nearly constant contact pressure between the heating elements and the electrode ring surface under varying thermal and physical conditions and prevents overheating and failure of the electrode ring.

Abstract: Items are coated with substantially homogeneous pyrolytic carbon by first heating them to the desired temperature, e.g., about 1200.degree. C. to 1600.degree. C. in a nonoxidizing atmosphere. A mixture of gas including an inert gas portion and a hydrocarbon portion is supplied to the heated enclosure at a rate so that the mixture approaches the temperature of the heated items and the hydrocarbon decomposes. The hydrocarbon portion includes between about 25 and about 60 volume percent acetylene and the remainder propylene. The exothermic characteristics of acetylene is such that the heat given off upon decomposition is sufficient to sustain the coating reaction.

Abstract: A fuel element is formed with a plurality of fuel rod assemblies detachably connected to an overhead support with each of the fuel rod assemblies having a gas tight seal with the support to allow internal fission gaseous products to flow without leakage from the fuel rod assemblies into a vent manifold passageway system on the support. The upper ends of the fuel rod assemblies are located at vertically extending openings in the support and upper threaded members are threaded to the fuel rod assemblies to connect the latter to the support. The preferred threaded members are cap nuts having a dome wall encircling an upper threaded end on the fuel rod assembly and having an upper sealing surface for sealing contact with the support. Another and lower seal is achieved by abutting a sealing surface on each fuel rod assembly with the support. A deformable portion on the cap nut locks the latter against inadvertent turning off the fuel rod assembly.

Abstract: A neutron flux monitoring system is described for a nuclear reactor which enables the monitoring of very low levels of neutron flux such as may exist during the shutdown condition of the reactor. The pulses produced in the flux detectors distributed around the reactor core and ordinarily used for power range monitoring are conveyed, by isolation means, to summing means which provide a count rate output corresponding to the total number of pulses produced by all of the neutron flux detectors.

Abstract: A nuclear reactor having a large prompt negative temperature coefficient of reactivity. A reactor core assembly of a plurality of fluid-tight fuel elements is located within a water-filled tank. Each fuel element contains a solid homogeneous mixture of 50-79 w/o zirconium hydride, 20-50 w/o uranium and 0.5-1.5 w/o erbium. The uranium is not more than 20 percent enriched, and the ratio of hydrogen atoms to zirconium atoms is between 1.5:1 and 1.7:1. The core has a long lifetime, e.g., at least about 1200 MW days.

Abstract: An annular heat exchanger assembly is described which is particularly suited for structurally self supporting installation in a vapor generator associated with a nuclear reactor. The assembly includes parallel inlet and outlet header conduits interconnected by a multiplicity of helical tubes, adjacent portions of these tubes being tied together to increase structural integrity of the annular tube bundle formed by the helical tubes. Various baffles are employed as necessary to promote uniform flow of a heating fluid over the tubes in the tube bundle, preferably in a radial direction of flow.

Abstract: Apparatus is disclosed for generating electrical pulses in response to rotation of a shaft. The apparatus incorporates an internal optical disc carried by a hub assembly attached to the operating shaft, with the hub assembly having a beveled bearing surface at one end thereof for engaging a similarly beveled surface of the apparatus housing, and biasing means for biasing the hub assembly toward said housing beveled surface to compensate for mechanical wear and to also minimize erratic movement of the optical disc. The combination of a light emitting diode and photo-transistor generate electrical signals in response to the blocking and transmitting of light through radially oriented opaque segments of the disc during rotation. The light emitting diodes and photo-transistors are retained by receptacles which snap fit within cooperating apertures of the housing.

Abstract: The components of a liquid mixture consisting essentially of HI, water and at least about 50 w/o iodine are separated in a countercurrent extraction zone by treating with phosphoric acid containing at least about 90 w/o H.sub.3 PO.sub.4. The bottom stream from the extraction zone is substantially completely molten iodine, and the overhead stream contains water, HI, H.sub.3 PO.sub.4 and a small fraction of the amount of original iodine.When the water and HI are present in near-azeotropic proportions, there is particular advantage in feeding the overhead stream to an extractive distillation zone wherein it is treated with additional concentrated phosphoric acid to create an anhydrous HI vapor stream and bottoms which contain at least about 85 w/o H.sub.3 PO.sub.4. Concentration of these bottoms provides phosphoric acid infeed for both the countercurrent extraction zone and for the extractive distillation zone.

Abstract: In plasma arc welding apparatus of a type including a plasma arc torch which is movable relative to a welding stock and transforms orifice gas into a plasma jet stream directed toward the welding stock, the flow of orifice gas is regulated by a throttle valve, a motor adjusting the valve under the influence of adjustable timing means capable of selectively increasing, decreasing and maintaining at a steady state the flow of orifice gas toward the torch. In order to accurately regulate the throttling valve, the timing means preferably includes an adjustable cam assembly driven by the motor along with the valve and operatively coupled with the motor by one or more switches capable of regulating motor operation in order to achieve desired flow control by the valve.

Abstract: A wind driven power apparatus for converting wind to mechanical energy is disclosed which includes a fixed axis turbine supported centrally of a fixed air guide defining a plurality of horizontal air passages disposed circumferentially of the turbine and each being adapted to receive an air stream therein coming from a limited range of wind directions and effect accelerated air flow toward the turbine. In one embodiment, an air guide block is disposed circumferentially of the turbine and is rotatable about the axis of the turbine to direct accelerated air flow to the turbine from the windwardly facing ones of the air passages, while in alternative embodiments means are provided for selectively closing off the air passages so that accelerated air flow from selected air passages is directed to the turbine.

Abstract: A method and apparatus for pneumatically loading an array of nuclear fuel rods into suitable storage containers and also for removing them therefrom. Within the method and apparatus, a vacuum is developed to hold the fuel rods in place upon a transfer unit, the vacuum condition being selectively terminated in order to release the fuel rods for unloading. Preferably, air pressure is employed to more rapidly eliminate the vacuum condition and facilitate release of fuel rods. The vacuum condition is maintained by outside air flow restricting passages if one or more fuel rods are missing from the array to be transferred.

Abstract: A support assembly in a heat exchanger for securing tubes of a tube bundle in parallel, spaced-apart relation includes a plurality of concentrically arranged tube support rings for respectively securing circumferential groups of tubes in the tube bundle, each tube support ring being formed with inner and outer cylindrical support elements rigidly interconnected by a number of circumferentially spaced apart radial bars.

Abstract: A continuous reaction is carried out between gaseous SO.sub.2, I.sub.2 and liquid H.sub.2 O in a substantially vertical reaction zone. H.sub.2 O plus I.sub.2 in a substantial excess are supplied to an upper location at preselected rates. SO.sub.2 is injected into the zone at a lower location, and a desired temperature is maintained at an intermediate location where the reaction proceeds to produce sulfuric acid and hydrogen iodide. The reaction products are removed from a location near the bottom at a rate proportional to the preselected rates to cause a continuous downward flow within the reaction zone. The SO.sub.2 flow rate assures that substantially all of the SO.sub.2 either reacts or is absorbed by the downward traveling nongaseous reactants.

Abstract: Biocompatible artificial tendon or ligament prostheses having an exterior adherent coating of vapor deposited carbon, comprising a strand of a plurality of fibers each of which is designed to sustain a tensile strain of about 5 percent or less and means for attaching the strand at the implantation site.

Abstract: The first wall of a deuterium-tritium fusion reactor is regenerated in situ. The first wall substantially surrounds an enclosed reaction region confined within the reaction chamber of the reactor. To regenerate a worn first wall without opening the reactor chamber, a gaseous substance is introduced into the chamber, at least a portion of the gaseous substance comprising material, such as low Z refractory material, suitable for forming the first wall. At least a portion of this material is deposited, as by pyrolysis, in solid form on the first wall to regenerate the first wall, and residual gas is removed from the chamber. The chamber is then recharged with a mixture of deuterium and tritium. All the while the inflow of contaminants into the chamber is substantially excluded. Preferably, the pyrolysis of the gaseous substance is effected by energizing the coils used in the operation of the reactor for producing a plasma of deuterium and tritium ions in the reaction chamber.

Abstract: In one embodiment, a closed cycle gas turbine system employs a precooler for cooling the gas prior to compression. A closed loop coolant circuit for the precooler includes a primary heat exchanger. A secondary heat exchanger is provided which may be employed during periods of peak demand on the turbine system to provide additional cooling for the coolant in the closed loop coolant circuit for the precooler. The secondary heat exchanger may also be employed to transfer heat in the reverse direction during periods of time in which the primary heat exchanger is operating at high effectiveness to provide storage of a fluid at low temperature to enhance operation in the initially described mode. In another embodiment, a similar coolant circuit operates in conjunction with a condenser for a steam power electrical generating facility.

Abstract: A battery backup system provides DC power to a data processing system in the event of an AC power failure. A preferred embodiment supplies DC power from a plurality of series-connected batteries at a voltage level sufficient to operate a data processor. After a time delay, the batteries are connected in parallel to provide DC power at a lower voltage level sufficient to maintain information stored in a memory.

Abstract: Hydrogen is produced by bombarding a mixture of water and heavy elements having an atomic weight of at least about 40 with fast neutrons so as to cause thermal dissociation of the water to produce hydrogen ions following elastic collision of the fast neutrons with the heavy elements. The hydrogen ions are removed from the reaction zone to prevent recombination to water, maintaining conditions which favor combination to molecular hydrogen or combination with carbon to form hydrocarbons.