Abstract: Apparatus for controlling a nuclear reactor by vertical displacement of a unit absorbing neutrons, comprising, inside a sealed enclosure (1) in communication with the interior of the reactor, a movable magnetic piece (6) connected to a control shaft (3) which is itself connected to the absorbent unit. This magnetic piece (6) has at least two radial projections (7). The magnetic piece (6) is displaced by an inductor (10) with at least two pole shoes (16) corresponding to the projections (7) on the magnetic piece (6) and allowing magnetic coupling between the inductor (10) and the magnetic piece (6). The inductor (10) and its displacement device (30, 32, 33) are disposed outside the sealed enclosure (1). A control means (38) allows the control shaft (3) to be uncoupled from a member (36, 37) assuring its suspension so as to drop the absorbent unit in the event of emergency shutdown. The apparatus is particularly applicable to control rods of pressurized water nuclear reactors.

Abstract: A fuel assembly for a boiling reactor is constructed according to the accompanying drawing (FIG. 1). Preferably, only partial spacers (6) are used in the fuel assembly. Each partial spacer positions only a minor portion of the total number of fuel rods in the assembly. Groups of partial spacers are arranged axially one after the other, the partial spacers in each group being positioned at at least two different levels and together positioning all fuel rods in the fuel assembly.

Abstract: A turbine blade for a gas turbine engine has a hollow aerofoil and a root. A first insert for the distribution of cooling air in the aerofoil is inserted thereinto through an opening in the root but due to the relatively high camber of the blade the insert is such that it has to be displaced laterally after insertion. A second insert, also inserted through the opening, is provided to secure the first insert in position and to guide the cooling air from the opening to the first insert.

Abstract: The present invention relates to an electric igniter of the type which comprises two electrically conducting bodies (8, 9) separated by an electrically insulating body (10). The conductive and insulating bodies define a very smooth common end surface (13) with an interconnecting member (20) for electrically connecting the conductive bodies (8, 9). A pyrotechnic charge (14) is in contact with the interconnecting member (20 ) for ignition when said member is heated by flow of electric current therethrough. The interconnecting member (20) comprises at least one relatively thin metal layer (21, 22) which is bonded to said smooth end surface and a thin inert layer (23) applied directly on the metal layer (22). In addition to said layers the interconnecting member (20) also comprises a metal thin film layer (24) applied directly on the inert layer, the interconnecting member (20) being adjusted to its correct resistance value by means of oxidizing the metal layer (22) adjoining the inert layer (23).

Abstract: A core shroud including flexible panels sealingly attached to the inner surface of the shroud at an elevation opposite the fuel assembly grids nearest the core midplane. Each panel forms the outer wall of a deformable chamber which is pressurized through a conduit carried by the shroud. One end of the conduit is in fluid communication with the reactor coolant at a high pressure location remote from the panels, producing a pressure differential across the panel which urges the panel against the adjacent grid to prevent core bowing.

Abstract: In a method for the controlled removal of hydrogen released into the chambers of a nuclear reactor containment after a break of the primary cooling system, the hydrogen is contacted with an oxygen providing material stored in the containment which causes recombination of the hydrogen to H.sub.2 O in a controlled manner at least until the amount of the gas within the hydrogen chamber is below the ignition limit of a hydrogen oxygen gas mixture.

Abstract: A filter assembly for a luminaire for preventing contaminants and impurities from entering the sealed enclosure of the luminaire while permitting air to pass into and out of the sealed enclosure. The filter assembly includes a fitting and a cap. The fitting has an axially extending passageway opening at its opposite ends and a cavity receiving an air-permeable filter across the passageway. The cap has a first portion coupled to the fitting to cover one end of the fitting passageway, a second portion extending laterally from the first portion and a solid back member extending over the first and second portions. The first and second portions and the back member define a non-linear passageway in fluid communication with the fitting passageway to permit air to flow into and out of the luminaire sealed enclosure through the filter, while protecting the filter from the elements.

Abstract: A missile or rocket detent and positive release mechanism, actuated by the rocket's thrustor, is mounted on the outside of a rocket launcher tube. A notched-end (52) of a spring-loaded lever (50) extends into the launch tube for positively locking a rocket (10) into place. One end of a sear (60) extends over the spring lever for maintaining the lever in its locked position. A toggle lever (44) is pivotally connected to the other end of the sear and extends into the blast region of the rocket, whose high speed exhaust gasses cause it to be pivoted out of the way, to withdraw the sear from the spring loaded lever, and thus to permit release of the rocket.

Abstract: Apparatus for detecting ferromagnetic material such as is present in an explosive cartridge being loaded into a borehole, e.g., according to the method described in U.S. Pat. No. 3,986,430, which includes an inductance coil connected in series with a resistor, separately rectifies and amplifies the AC voltages across the coil and resistor and connects them in series opposition. The value of the balancing resistance is adjusted so that the two rectified voltages are equal and opposite when no ferromagnetic material is present. When the unbalance voltage exceeds a threshold value, a signalling device is actuated.

Abstract: A plurality of radially arranged and neutron absorbing baffles are stacked in vertical sets under the fuel core assemblies, and the whole enclosed in a bottle shaped containment vessel. The radially arranged baffles of each set extend vertically, and each set has double the number of baffles as the set above it in the stack. A melt-down of a fuel core assembly drops the fissioning nuclear fuel into the stacked sets of baffles, there, as it passes through, to be progressively divided, redivided and dispersed in smaller and smaller masses between the doubling number of baffles in safe fuel pellet size. Neutron absorbing containment prevents contamination of the environment and together with cooling means stops fissioning of fuel.

Abstract: An improved hand grenade incorporating safety features including a normally uncocked striker arm and a protective shield over the primer. Because the striker spring is normally unstressed, the major working parts of the grenade may be inexpensively made from plastics.

Abstract: A photoflash unit having a plurality of flashlamps mounted in a planar array on a printed circuit board containing circuitry for sequentially igniting the flashlamps in response to successive firing pulses applied thereto. The circuitry includes a plurality of solid state switches capable of being activated by radiant energy generated during flashing of lamps located adjacent to respective switches. Initially, each of the switches has a resistance sufficiently high to provide an open circuit to the applied firing pulses, and after being activated by radiation, the switch undergoes chemical conversion to a conductive state. The switches are prepared from compositions which include a selected proportion of silver-coated glass beads to consistently assure a predetermined low resistance after conversion and maintenance of good adherence and electrical contact with the printed circuit board circuitry.

Abstract: A smoke cup projectile charge comprising smoke cups stacked one above the other in the shell jacket in discharging direction, the smoke cup supporting components having identical strength and being filled with smoke charge composition comprising hexachloroethane, zinc oxide and metal powder, and a fuse system of priming cartridges embedded in transmission composition in the smoke charge and ignited by capillary delay tubes.

Abstract: Processes are disclosed for the separation of isotopes of an element comprising vaporizing uranyl compounds having the formula (UO.sub.2 A.sub.2).sub.n, where A is a monovalent anion and n is an integer from 2 to 4, the compounds having an isotopically shifted infrared absorption spectrum associated with uranyl ions containing said element which is to be separated, and then irradiating the uranyl compound with infrared radiation which is preferentially absorbed by a molecular vibration of uranyl ions of the compound containing a predetermined isotope of that element so that excited molecules of the compound are provided which are enriched in the molecules of the compound containing that predetermined isotope, thus enabling separation of these excited molecules. The processes disclosed include separation of the excited molecules by irradiating under conditions such that the excited molecules dissociate, and also separating the excited molecules by a discrete separation step.

Abstract: A portable lighting system which includes a stand having an adjustable effective length which positions lights carried on a frame at a predetermined vertical position with respect to a supporting surface. The frame is releasably secured to the stand and can readily be set up and dismantled for transport in a compact space. Lights carried by the frame include a new and simple technique for attaching the gelatine filter holders, and may be connected to a foot operated control box which includes switches actuated to energize preselected lights or groups of lights. The energized lights or preselected energized lights can be intensity modulated with a foot operated dimmer while leaving the operator's hands free to play a musical instrument.

Abstract: This present invention provides a process of recovering uranium from a uranium-containing acid lixiviation solution comprising extracting the lixiviation solution with an organic extractant comprising an organic diluent, a dialkyl pyrophosphoric acid, and a stabilization agent, and treating the mixture of solutions as follows:(a) bubbling anhydrous ammonia gas into the solution mixture to precipitate the ammonium salt of excess dialkyl pyrophosphoric acid; and(b) separating the precipitate from the solution and recovering the uranium from the solution.

Abstract: An adjustable recessed electrical lighting fixture utilizing an electrical socket which engages a lamp. A mounting plate surrounds at least a portion of the lamp. A frame having a pair of legs pivotally connects the mounting plate and provides support for the electrical socket. The frame is pivoted in relation to the mounting plate to provide adjustment about a horizontal axis. A race which contacts at least a portion of the mounting plate is movable in relation to the mounting plate to provide adjustment about a vertical axis.

Abstract: A method of controlling the molybdenum content of uranium yellowcake which is precipitated from an eluate of ammonium carbonate. The pH of the eluate is maintained at a relatively high value, i.e., never less than 9.3, while the eluate is heated to strip off ammonia, carbon dioxide, and water. Ammonia is added to the eluate during heating to keep the pH high and the molybdenum in solution in the eluate. Also, the precipitated uranium yellowcake may be treated by adding aqueous ammonia and heating to form an insoluble uranium salt and a soluble molybdenum salt which can be filtered to produce a uranium yellowcake having a reduced molybdenum content.

Abstract: The efficiencies of laser isotope separation processes based on multiple photon absorption from infrared laser pulses are enhanced thermally by raising the temperature of the gas upon which the laser beam is incident, thereby increasing the absorption and the isotopically selective excitation which enables isotopes in the gas to be separated. This same enhancement is applicable to processes for laser purification of gases which involve multiple photon absorption from infrared laser pulses.

Abstract: This application discloses a method of separating the isotopes of an element which form a volatile compound having an isotopically shifted but overlapping infrared absorption spectrum. In the method, IR radiation of first and second laser frequencies are employed. The first infrared laser frequency produces a selective excitation of the desired isotope of the compound, while the second infrared laser frequency produces a higher multiphoton excitation which allows conversion of the excited compound.