Abstract: An apparatus for the safe storage of a plurality of fissionable masses including an array of discrete neutron absorbing shields which utilizes the principle of the neutron trap to reduce the multipication factor of the storage array to a subcritical value when immersed in a neutron moderating medium. Each discrete neutron absorbing shield is designed to perimetrically encircle each of the stored fissionable masses. Each shield is spaced such that the encircled fissionable mass is spaced from the next adjacent neutron absorbing shield by a distance determined by the enrichment of the fissionable masses and attenuation of the moderating medium.

Abstract: An output stage and feedback circuit for a buffer amplifier are disclosed. The output stage protects an operational-amplifier circuit preceding it from overvoltages appearing at the load. The circuit includes a pair of complementary transistors in a push-pull arrangement that sources and sinks current to and from the load. Both the transistors are in common-emitter configurations, and each one has a corresponding diode connected between its collector and the load in an orientation opposite that of the collector-base junction. The diodes prevent the reverse current that would otherwise flow in response to an output overvoltage of the polarity that forward biases the collector-base junction of the transistor, and the over-voltage is thereby prevented from being seen at the operational-amplifier output terminal. Overvoltages of the other polarity are not seen because they reverse bias the base-collector junction.

Abstract: An arrangement for a steam cooled spacer tube which restrains movement of pendantly supported superheater division panels of a steam generator. A horizontal portion of the spacer engages the panel and a vertical portion engages a pair of bumped furnace wall tubes at a restraining area. A freely rotatable sleeve surrounds the spacer at the restraining area, and a sleeve surrounds each of the bumped furnace wall tubes.

Abstract: A shipping and handling fixture for a large rigid load such as a steam generator or other vessel in which the fixture is incorporated with the load to provide a carrier having wheeled sections at opposite ends thereof that comprises a vehicle commonly known as a Schnabel-type railway or over-the-road car. The handling fixture includes a longitudinal support skid that underlies the vessel and is held in tension between wheeled sections of the car while the vessel itself becomes a stuctural part of the carrier that transmits compressive forces between oppposite ends of the car.

Abstract: A flow monitoring system which utilizes the decay of a measurable parameter of the flowing fluid by measuring the magnitude of the parameter at two spaced points along the flow of the fluid. Accurate measurements are enabled by the elimination of detector identity and calibration problems by repeatedly translating one detector between first and second positions external to the fluid conduit along the flow path of said fluid. This translation is preferably accomplished by a pendulum device with the detector positioned at the end of the pendulum.

Abstract: A shock buffer is provided for the gradual deceleration of a rapidly descending control element assembly in a nuclear reactor. The interactive buffer components are associated respectively with the movable control element assembly and part of the upper guide structure independent of and spaced from the fuel assemblies of the reactor.Preferably, the buffer is of the piston and cylinder type, with a piston extending upward from a tube sheet of the upper guide structure and a cylinder opening downward and carried by the control element assembly near its upper end. The cylinder descends about the buffer piston near the lower extent of control element assembly travel. Liquid naturally occupying the buffer cylinder, as the reactor coolant at the ambient pressure within the reactor, provides hydraulic decelerating forces on the control element assembly when relative insertion of the piston in the cylinder occurs.

Abstract: A steam generator having a coal fired furnace including water cooled walls, and having a hopper bottom. A plurality of steel struts are provided which extend between the furnace walls at a level at or above the top of the hopper bottom, and the furnace inlet ring header located at the bottom of the hopper, so that the unit can be bottom supported. The steam generating tubes extending upwardly out of the ring header and forming the furnace walls each contain a bend therein, so as to be flexible enough to accommodate differential thermal growth of the struts relative to the adjacent furnace walls during transient temperature occurrences.

Abstract: A "package-type" boiler fired by pulverized coal that is adapted to be constructed and assembled in a shop then shipped as a completed unit to a given plant site. The boiler is provided with tube walls extending between longitudinally disposed drums that simultaneously provide optimum heat transfer along with internal support. The walls are bent to a configuration that imparts to the boiler a hopper-shaped bottom wall on opposite sides of an elongate throat through which solid products of combustion may be discharged.

Abstract: A nuclear reactor fuel assembly having an easily disassembled threaded connection between the end fitting and the control rod guide tubes. More specifically, the threaded connection is formed between the upper and/or lower alignment posts and the guide tubes and clamps the fuel assembly end plate therebetween. The sizing and arrangement of the connections is such that the assembled joint may be subjected to thermal cycling without incurring excessive stresses or deformations.

Abstract: A fluid driven actuator for a neutron absorber in a nuclear reactor is of the piston and cylinder type. The actuator is located above the reactor core. Means are provided for alternately opening and closing a by-pass fluid flow path or passage through or across the piston within the cylinder. The flow path is closed when the piston and control rod is being raised and is subsequently opened to reduce flow resistance during insertion or scram. In the preferred embodiment, the piston is longitudinally movable relative to the piston or extension rod which connects with the neutron absorber. In one position of the piston, the by-pass path is open and in another position, it it closed.

Abstract: An improved method and apparatus for the submerged arc surfacing of metallic work pieces with metal electrode strips melting in an electric arc while forming welding beads upon the work piece. The apparatus comprises a work piece which is to be surfaced, an electrode strip comprising the cladding material, means operative to move the strip and work piece relative to one another, a DC source, the opposite poles of which are connected to the electrode strip and the work piece, an electro-magnetic means having poles of opposite polarity operatively positioned at opposite sides of the electrode strip and adjacent the pool of molten flux and molten metal lying behind the electrode strip. The current to the electro-magnetic means is pulsed to thereby cause an agitation of the molten slag and weld deposit thereby resulting in a weld bead of extremely high quality, uniform thickness and also a defect-free tie-in between adjacent weld beads.

Abstract: An electric system normally responsive to radiation over a path traversed by a body of material. An auxiliary radiation source generates a continuous signal through the portion of the circuit monitored for failure. The continuous signal opposes deenergization of the system relay during the period the material blocks normal radiation to the system and while the monitored circuit is operative.

Abstract: Apparatus is described for supplying injection liquid to the primary coolant pump shaft seals in a pressurized water nuclear reactor system. The injection liquid is the resultant mixture of liquid extracted from both the upstream and downstream sides respectively of the regenerative heat exchanger in the chemical and volume control system of the plant. The temperature of this liquid is controlled by regulating the liquid proportions admitted in the respective flow streams.

Abstract: An apparatus for the safe storage of a plurality of fissionable masses including an array of discrete neutron absorbing shields which utilizes the principle of the neutron trap to reduce the multiplication factor of the storage array to a subcritical value when immersed in a neutron moderating medium. Each discrete neutron absorbing shield is spaced such that the encircled fissionable mass is spaced from the next adjacent neutron absorbing shield by a distance determined by the enrichment of the fissonable masses and attenuation of the moderating medium.

Abstract: A process for making an adjustable split door frame is disclosed, the process comprising the steps of cladding the front surface of the board with vinyl, grooving a plurality of parallel grooves of various shapes in the back surface of the board down to but not through the vinyl, folding and gluing the board along the grooves, inserting a support member and attaching a hard board to the back surface of the resulting door frame. In addition, a second board is clad, grooved and folded in a similar manner to provide the other half of the split adjustable door frame.

Abstract: A furnace has its interior walls covered with tubes which carry fluids being heated has supports for the tubes extended from the furnace shell. The supports are attached to the inside of the shell and extend beyond the refractory lining the shell. A strap member on each support extends from, and is movable in, tracks of each support to clamp a tube to the support.

Abstract: A main burner oil gun in which hard to ignite liquid fuels can be burned, including an ignition means for the oil gun which will reliably light the oil gun time after time. The oil is sprayed from the oil gun tip in the shape of a hollow cone. Air is introduced surrounding the oil gun, and flows over a baffle plate located transversely of the oil gun, creating eddies of air, some of which break through the curtain of fuel issuing from the tip in a conical shape. This current of air that breaks through the fuel carries some fine droplets of fuel along with it, and forms a recirculation zone extending back to the oil gun tip. The ignition means is located within the hollow conical fuel flow, along the inner edge of the recirculation zone, so that the initial flame established is carried back to a point directly in front of the oil gun tip.

Abstract: A system is provided for the relief of excess pressure from the region above the nuclear reactor core to the cold leg on the occurrence of a loss of coolant accident. This system includes a series of passages connecting the annulus surrounding the exterior of the core barrel with the interior of the outlet nozzle or with the plenum above the reactor core. A flow blocking obstruction, such as a seal band, is held in a flow blocking position by the differential pressure experienced during normal operation of the reactor between the exterior of the core barrel and the exit region of the reactor core. Reversal of the differential pressure, which may be expected upon the occurrence of a loss of coolant accident, removes the flow blocking obstruction to permit the relief of excess pressure which may result at the outlet end of the reactor core.

Abstract: A method and apparatus is disclosed for feeding welding flux to both the leading and trailing sides of the strip electrode used in a submerged arc strip cladding process. In order to prevent distortion of the bead shape the pressure due to the weight of the flux burden is controlled to be less in the region of the molten metal and slag pools lying directly behind the welding arc. The flux burden is caused to increase from a first depth directly behind the strip to a maximum depth at the trailing edge of the weld crater region where the quantity of liquid metal and liquid slag is a minimum.

Abstract: An actuator comprises a piston and cylinder in which the piston is biased axially inwardly of the end of the cylinder to an intermediate position by two bias members respectively on axially opposite sides of the piston. Limit means associated with each respective bias member serve to coact between the respective bias member and the cylinder to limit the inward travel of the respective bias member in the cylinder to establish a constant position at which the piston receives no net biasing force from the two bias members. Each limit means may comprise a flanged cup which moves with the inner end of the bias member and a stop surface in the cylinder for engaging the cup flange to limit its inward movement, and thus the inward movement of the bias member.