Abstract: An apparatus and method for loosening a mechanical plug in a tube. A cartridge having a nose portion, central portion formed from a material that produces an exothermic reaction when ignited, and a base is inserted into the plug to be loosened and removed. An insulated wire extends through the base into the central portion and is connected to a resistive noninsulated wire positioned in the central portion. Sending an electrical current through the wiring causes the noninsulated wire to heat up rapidly. The rapid heat buildup initiates an exothermic reaction in the central portion. The heat generated causes stress conditions in the plug that exceed plug yield and results in a stress relief condition in the plug where the diameter of the plug is reduced. This loosens the plug in the tube and reduces pulling forces needed to remove the plug from the tube.

Abstract: A gas cooled nuclear fuel element having a particle fuel retention device which acts as a passive restraint in the event of failure of hot frit. A particle fuel retention device is positioned either in the annular space within the inner frit, in the end cap through which coolant gas flows, or attached to the end cap and extending axially beyond the fuel element.

Abstract: This invention pertains to a braced offshore structure that is constructed on land as a single unit in a compact bundle before being transported on a barge to the installation site. After the compact unit is launched, it is unfolded and ballasted before being installed upon the ocean floor. This structure consists of an elongated central tower having a plurality of braces pivotally secured thereto. These braces are initially positioned generally parallel to this central tower within recesses in the central tower but after the braces are unfolded, they extend at an angle to the central tower.

Abstract: A nuclear fuel element for a particle bed reactor. Concentric inner and outer porous cylinders attached at either end define an annulus therebetween that contains a fuel particle bed of nuclear fuel material. The outer porous cylinder is provided with fins that extend radially outward along its entire length. A nonporous cylinder is attached to the outer porous cylinder at either end and is positioned around the outer porous cylinder so as to be concentric therewith. Flexible fins extend radially inward form the nonporous cylinder along its entire length and contact the fins on the outer porous cylinder for conduction of heat to heat removal tubes on the outer surface of the nonporous cylinder. The heat removal tubes allow bimodal cooling of the particle bed reactor.

Abstract: An end fitting for a fuel assembly. A lower plate having a pin extending perpendicular thereto at each corner slidably receives a main body portion on the pins. Stop washers or nuts on the pins prevent the main body portion from sliding off the pins. A hairpin shaped spring along each side of the main body portion is positioned between the plate and main body portion to resiliently bias them apart. The end of the spring against the lower plate is offset from the end of the plate to preload the spring tension.

Abstract: A locking bolt assembly that prevents the release of loose parts in the event of bolt failure. A bolt having a head and threaded main body portion is provided with a central bore through the head and main body portion. The central bore has a necked down area adjacent the end of the main body portion away from the head. A plurality of slots along the end of the main body portion in communication with the central bore form bolt fingers around the necked down area. A plunger slidably received in the central bore places radial pressure at the necked down area to expand the bolt fingers outwardly and lock the bolt in its installed position without changing the preload of the installed bolt. The plunger is retained in its bolt locking position and prevents the release of loose parts in the event of bolt failure.

Abstract: A method of inspecting tube welds in tubular membrane panel walls whereby a radiation source if placed intermediate adjacent tube welds with radiographic film positioned along the far wall of each adjacent tube thereby covering the far wall critical area of each tube weld. Simultaneously each radiographic film is exposed to an intermediate radiation source thereby creating an actual size image of each tube weld with both images totaling or equaling at least one full weld being radiographed per exposure.

Abstract: A method of inspecting a tube header bore comprises scoring an oxide scale layer within the bore using a hard scribing tool. The bore is then cleaned using one or more honing brushes having flexible bristles with carbide tips. After sufficiently cleaning the inner surface of the bore a florescent dye is applied to the surface for highlighting surface defects and a visual inspection is made. For easy access to the interior of the bore, the tube is cut at a point spaced from the bore. After the inspection is complete a new length of tube is connected such as by welding.

Abstract: An apparatus and method of sealing the cold leg nozzles of a reactor vessel during plant outages for reactor vessel inspection and core support maintenance includes insertion of a sealing plug into each of the cold leg nozzles, by means of an installation tool suspended within the vessel, to permit drainage of downstream piping and inspection and maintenance of associated steam generators and pumps.

Abstract: An improved method for removing sulfur oxides from a hot gas by introducing the gas into a first compartment of a spray drying reactor chamber for settleable particulate removal, by then directing the gas to a second compartment of the reactor chamber wherein the gas is contacted with an atomized alkali slurry for sulfur oxide removal by formation of a dry mixture of sulfite and sulfate compounds, by removing a portion of the dry mixture from the gas in the second compartment and by passing the gas from the second compartment to a dry particle collection zone for removal of substantially all of the remaining gas entrained dry mixture.

Abstract: An improved centrifugal separator for vapor-liquid mixtures having a vertical upflow conduit closed at the top end and open at the bottom end. A plurality of curved arms similar in shape to a truncated torus of rectangular cross-section penetrate and extend within the conduit at its upper portion. A second plurality of curved arms are located immediately below the upper group and are contiguous thereto. The vertical upflow conduit has a lesser internal diameter in the lower portion, interconnected with a greater internal diameter portion in the upper portion by a frusto-conical section.

Abstract: An apparatus for removing particulate matter from a flue gas stream exiting a vapor generator and recirculating said gas back to the generator. The apparatus includes a back face, a bottom face and a recirculation duct. The recirculation duct is located in front of the apparatus, thereby increasing the access area in the vicinity of the generator burners and facilitating maintenance of said burners. The back face, bottom face and recirculation duct envelope ash hoppers and other internal components of the apparatus.

Abstract: A pair of parallel fluid flow connected steam-water drums and associated piping for natural or assisted circulation steam generators including downcomer pipes for receiving water from the drums and being disposed below and in equispaced relationship with the drums. A plurality of supply tubes for connecting the downcomer pipes with each drum, the supply tubes being equally divided between the drums; and a plurality of riser tubes for delivering a steam-water mixture to the drums, the riser tubes being equally divided between the drums.

Abstract: The present invention relates to a solar central receiver or steam generating and superheating unit (20) comprised of a first and a second series of circularly disposed tube panels (21) and (23), respectively. The first series (21) including steam superheating tube panels (12-12') and (14-14') and the second series including steam generating tube panels (16-16'). The steam generating tube panels (16-16') being interposed between at least some of the steam superheating panels (12-12') and (14-14') and the solar heat source.

Abstract: A support structure for pressure vessels including a plate member welded to the vessel and a sleeve passing through the member and engaged by a pin and clevis type support.

Abstract: A hydraulic vibration brake for use in nuclear power plants is shown. The brake has a casing that a piston divides into two chambers. A storage tank in hydraulic fluid communication through appropriate conduits and valves maintains proper pressure in the system. The piston rod penetrates the casing wall and, at this penetration has a seal which arrests fluid leakage. In this manner, no hydraulic fluid is lost at the seals and sufficient fluid always is available to enable the brake to carry out its function, thereby eliminating the need for a number of burdensome inspections.

Abstract: A typical embodiment of this invention provides a hydraulic mechanism for alleviating the effect of seismic forces and other stresses that are applied to a fuel assembly in a nuclear reactor. Illustratively, hollow guide posts protrude into a fuel assembly end fitting grid from biased spring pads. Plungers that move with the spring pads plug one end of each of the respective guide posts. Plates on the end fitting grid that have individual holes for fluid discharge partially plug the other ends of the respective guide posts, thereby providing a hydraulic means for absorbing the longitudinal component of seismic shocks and other anticipated forces.

Abstract: A typical embodiment of the invention provides a nuclear fuel assembly lock structure for control rod guide tubes. Illustratively, a sleeve telescopes over an end portion of a control rod guide tube which bears against an internal shoulder of the tube. The upper end of the sleeve protrudes beyond the control rod guide tube spider and is locked in place by means of a resilient cellular lattice or lock that is seated in a mating groove in the outer surface of the sleeve. A special tool is provided for disengaging the entire lock structure, washer, spider, spring and grill from the end of the fuel assembly in order to enable these components to be removed in an assembled state and subsequently replaced on the fuel assembly after inspection and repair.

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 grouping of straight tubes, bundled and packed for shipment, having the tube ends on one end of the bundle deformed for locating and supporting the tubes in a tube sheet, with the deformations located and produced in a manner resulting in a compact shipping package and improvements in handling at the job site and place of manufacture.