Abstract: In a nuclear reactor (e.g. one having coolant down-flow through a core to a hearth below) thermal insulation (e.g. of a floor of the hearth) comprises a layer of bricks and a layer of tiles thereon, with smaller clearances between the tiles than between the bricks but with the bricks being of reduced cross-section immediately adjacent the tiles so as to be surrounded by interconnected passages, of relatively large dimensions, constituting a continuous chamber extending behind the layer of tiles. By this arrangement, lateral coolant flow in the interbrick clearances is much reduced.The reactor core is preferably formed of hexagonal columns, supported on diamond-shaped plates each supported on a pillar resting on one of the hearth-floor tiles.

Abstract: A method of starting operation of a nuclear reactor which contains fresh fuel rods comprising increasing a fuel power P(Kw/ft) produced by the fresh fuel rods to an amount determined by the following inequality;P< 366.times.(G/D)- 1.38,where D is a diameter of a fuel pellet of the fresh fuel rod and G is an initial gap between a fuel cladding of the fresh fuel rod and the fuel pellet, maintaining the fuel power at the amount for a predetermined period and thereafter increasing the fuel power to a desired maximum power level.BACKGROUND OF THE INVENTIONThe present invention relates to a method of starting operation of a nuclear reactor having fresh fuel rods of the type containing nuclear fuel covered with fuel rod claddings. (The term "fresh fuel rod" is utilized herein to designate a fuel rod which has not been irradiated or used.

Abstract: An actuating mechanism for actuating electrical switches to insure coordinated connection of circuits vital to safe operation of a mass-transit vehicle includes a frame upon which are mounted one or more electrical switches. Also included is a cam rotatably mounted on the frame for actuating engagement with the switches upon rotation of the cam by key or similar device. The actuating mechanism further includes a toggle mechanism that is connected at one end to the frame and at the other end to the cam at a point spaced from the point of mounting of the cam to the frame. Secured to the toggle mechanism is a spring whose dead center position does not coincide with the point of actuating contact of the cam with the switch such that upon rotation of the cam, the spring resists movement of the cam until the dead center position of the spring is reached.

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: The present invention is a method and an apparatus for guiding a rotating moving body to keep it on course towards a target, this method and apparatus comprising emitting electromagnetic radiation, with the aid of a radiation emitter having a variable-focus optical system enabling the body to be followed during its flight, having a very short wave length and in the form of a beam which is amplitude modulated in such a way that different areas over a cross section of the beam in a plane passing through the body being guided contain respectively radiation of high and low intensity, sweeping this beam with at least one radiation detector mounted on the body being guided and calculating, from the signals emitted by one or more detectors, the data necessary for automatically guiding the body along an axis extending between the center of the amplitude modulated beam and the target.

Abstract: An emergency retraction means is provided for removing the extended manipulator arm of a nuclear reactor vessel inspection device from within a nozzle thereof or from a fully extended position should power for normal extension drive fail. A cable is looped about the interior of a carriage assembly which drivingly engages the remainder of the manipulator arm. The cable is fixedly clamped at one location within the carriage assembly and looped about a first idler pulley mounted in the manipulator arm and is guided therefrom by another idler to an accessible point where the end of the cable is formed into a ring. The ring is detachably secured thereat to the carriage assembly.When an emergency occurs, a hook is lowered to engage the ring and is then lifted to detach it from the carriage assembly and move it upwardly therefrom.

Abstract: Liquified coal fuel is maintained in a liquified state by surrounding the injection pump, injection nozzle, suction line, pressure line and overflow line with jackets through which a heating medium is passed. The jackets surrounding the suction line, overflow line and pressure line are corrugated for expansion and are connected via bellows-like sealing bodies and flanges to the jacket surrounding the pump housing. Outlets are provided for leakage and are connected to separators to remove the fuel from the heating medium.

Abstract: A bed light safety apparatus which includes a normally wall mounted lighting fixture. The upper rearward edge of the fixture is pivotally mounted to a plate adapted for attachment to a wall. One embodiment of the apparatus includes a switch carried by the fixture. When used in conjunction with a hospital bed or the like which is power operated to a raised position, the switch is made a part of the electrical circuit for the bed drive means. In the event equipment carried by the bed strikes the fixture on raising of the bed, the consequent pivotal movement of the fixture causes the switch to open the circuit to the bed drive means and halt further raising of the bed. In other embodiments the safety apparatus may include visual or auditory alarms actuable by a switch in the fixture.

Abstract: A combined baggage rack and overhead light assembly for attachment to an interior wall of a vehicle includes a pair of parallel support arm assemblies extending outwardly away from the wall for receiving a grill which provides the baggage rack. An elongated overhead light fixture housing is connected below the baggage rack and includes a pair of elongated tracks having an elongated opening therebetween to receive a plurality of light fixtures. The light fixtures are adapted to be moved on the tracks to different desired positions, dependent upon the seating arrangement in the vehicle, prior to securing them in place on said tracks. Panels of predetermined lengths are placed between adjacent pairs of light fixtures after fixtures are secured in place.

Abstract: Nuclear fuels in the form of rod bundle with one or several beryllium rods inserted therein are proposed for use in power reactors positioned to obtain reactivity increase in order to save the D.sub.2 O inventory in a heavy water reactor or to relax the requirement of uranium enrichment if used in light water reactors.

Abstract: A personal security device incorporated into a conventional flashlight for informing a person, by remote control means, who is outside the door of the house, and indicating by a picture, whether it is a man, woman or child, the picture appearing on a view screen of a unit mounted on the flashlight, so that a person is thus cautioned against opening the door, particularly if there is a man outside.

Abstract: An auxiliary cooling device for a primary fluid heat exchanger of a rapid neutron nuclear reactor, the exchanger having at least one nest of tubes in which there flows water to be heated to superheated steam and around whose tubes and inside whose casing there flows a liquid alkaline metal constituting the primary fluid. The casing of the exchanger is surrounded by a jacket having an air inlet tube and an air outlet tube at opposite ends. Inside the jacket there are auxiliary heat exchange surfaces such as spikes projecting from the casing of the primary heat exchanger proper. Application is to the absorption of residual power produced by a rapid neutron reactor after it is shut down.

Abstract: A lighting fixture of square, rectangular or triangular shape consisting of a completely enclosed metal box within which the wiring and ballast transformers are contained, with integral portions of the box providing supports for one or more fluorescent lamps and thereby completely eliminating the need to secure to the body of the fixture separate support clips for the lamps. Reductions in material and manufacturing costs as well as shipping costs are realized because of reductions in material used, assembly time and physical size. The closed box configuration permits open suspension mounting, and the geometry is such that heat to which the ballasts are subjected is reduced.

Abstract: Disclosed are a method and apparatus for regulating and shutting down a gas cooled nuclear reactor having a bed of spherical fuel elements, wherein regulation of the reactor is accomplished by a first set of absorber rods in the side reflector of the reactor, partial shutdown is achieved by a second set of absorber rods movable in the top reflector and in the space above the fuel elements, and total shutdown is accomplished by a third independent set of absorber rods which can be moved downwardly into the fuel elements.

Abstract: A circuit for controlling the current supplied to an ignition coil is usable in conjunction with an electronic ignition. In one embodiment a transistor is connected in shunt with the input of a current amplifier and has a control electrode connected to a voltage divider a portion of which is in series with the coil, so that the transistor is responsive to both battery voltage and coil current. Excessive voltage or coil current causes the transistor to conduct thereby lowering the input signal to the current amplifier and reducing the coil current.

Abstract: After a nuclear reactor is shut down, the top of a nuclear fuel assembly in the core of a reactor pressure vessel is covered with a cap through which an air supply line, a warm water supply line and a sampling line extend. Air is supplied through the air supply line to form an air layer in the cap to stop the passage of a current of cooling water through the fuel assembly. A portion of the cooling water in the reactor pressure vessel is pumped up and heated to prepare warm water which is supplied through the warm water supply line to the fuel assembly so as to replace the cooling water in the fuel assembly by the warm water. After the fuel assembly is filled with the warm water, the fuel assembly is allowed to stand as it is for a predetermined period of time, and then a portion of the warm water in the fuel assembly is sampled. The radioactivity of the sample of the warm water is measured thereby to detect whether any of the nuclear fuel elements constituting the fuel assembly under test is a faulty element.

Abstract: A spring clip is secured to a support at each end of a light fixture such as a fluorescent light fixture and the clip extends downwardly therefrom. It is provided with at least one projection which snap engages a bead formed on the upper end edges of a lens component thus detachably securing the lens in position in an easy and unobtrusive manner.

Abstract: A control rod assembly for a nuclear reactor is disclosed having a remotely disengageable coupling between the control rod and the control rod drive shaft. The coupling is actuated by first lowering then raising the drive shaft. The described motion causes axial repositioning of a pin in a grooved rotatable cylinder, each being attached to different parts of the drive shaft which are axially movable relative to each other. In one embodiment, the relative axial motion of the parts of the drive shaft is used either to couple or to uncouple the connection by forcing resilient members attached to the drive shaft into or out of shouldered engagement, respectively, with an indentation formed in the control rod.

Abstract: A solid state timing circuit exhibiting very high reliability under adverse environmental operational conditions such as are encountered in automatic truck lubrication systems. The circuit utilizes an electrochemical timing device operating in plate and deplate modes to achieve a periodic actuation of an inductive load. Two transistor stages are operatively associated with the electrochemical timing device and an R-C timing network is used to control one of these transistor stages.

Abstract: A simplified guidance system for air-to-air missiles where the pilot adjusts his helmet sight to compensate for missile errors and this information is fed to a computer which computes correction data from error information, aircraft position information and missile position information, correction data is then sent via a radio link to the missile control system which changes the flight path accordingly.