Abstract: Improved core servicing apparatus for a nuclear reactor of the type having a reactor vessel, a vessel head having a head penetration therethrough, a removable plug adapted to fit in the head penetration, and a core of the type having an array of elongated assemblies. The improved core servicing apparatus comprises a plurality of support columns suspended from the removable plug and extending downward toward the nuclear core, rigid support means carried by each of the support columns, and a plurality of servicing means for each of the support columns for servicing a plurality of assemblies. Each of the plurality of servicing means for each of the support columns is fixedly supported in a fixed array from the rigid support means. Means are provided for rotating the rigid support means and servicing means between condensed and expanded positions.

Abstract: A rod type wet scrubber having two trays or decks of rods that are normally in space relation relative to the gas flow and wherein alignment of the rods is initially achieved by mounting them in a manner that will permit lateral movement and then bringing the two trays together such that the rods are interspersed in contact and accurately aligned with each other. The rods of each tray are then secured in place in their respective positions to thereafter prevent lateral movement therebetween.

Abstract: Improved nuclear reactor arrangement to facilitate both through the head instrumentation and insertion and removal of assemblies from the nuclear core. The arrangement is of the type including a reactor vessel head comprising a large rotatable cover having a plurality of circular openings therethrough, a plurality of upwardly extending nozzles mounted on the upper surface of a large cover, and a plurality of upwardly extending skirts mounted on a large cover about the periphery or boundary of the circular openings; a plurality of small plugs for each of the openings in the large cover, the plugs also having nozzles mounted on the upper surface thereof, and drive mechanisms mounted on top of some of the nozzles and having means extending therethrough into the reactor vessel, the drive mechanisms and nozzles extending above the elevation of the upwardly extending skirts.

Abstract: A firetube is mounted in a body of liquid to transmit heat to the liquid. A burner of fluid fuel is attached to one end of the firetube to discharge products of combustion into the firetube. The cooled products are discharged from the other end. The last portion of the firetube in the liquid bath has a series of tubes mounted through its walls. Liquid of the bath passes through the tubes and is heated by the products of combustion in contact with the tubes from within the firetube.

Abstract: A new part length rod is provided which may be used to not only control xenon induced power oscillations but also to contribute to shutdown reactivity when a rapid shutdown of the reactor is required. The part length rod consists of a control rod with three regions. The lower control region is a longer weaker active portion separated from an upper stronger shorter poison section by an intermediate section which is a relative non-absorber of neutrons. The combination of the longer weaker control section with the upper high worth poison section permits the part length rod of this invention to be scrammed into the core, when a reactor shutdown is required but also permits the control rod to be used as a tool to control power distribution in both the axial and radial directions during normal operation.

Abstract: A buckstay arrangement for a steam generator whereby tube walls of the steam generator are supported by buckstays having retainers that slide longitudinally to permit thermal expansion thereof while providing continuous support for the tube walls.

Abstract: The ability of a nuclear reactor to withstand high seismic loading is enhanced by including, on each fuel assembly, at least one seismic grid which reduces the magnitude of the possible lateral deflection of the individual fuel elements and the entire fuel assembly. The reduction in possible deflection minimizes the possibility of impact of the spacer grids of one fuel assembly on those of an adjacent fuel assembly and reduces the magnitude of forces associated with any such impact thereby minimizing the possibility of fuel assembly damage as a result of high seismic loading. The seismic grid is mounted from the fuel assembly guide tubes, has greater external dimensions when compared to the fuel assembly spacer grids and normally does not support or otherwise contact the fuel elements.

Abstract: The strength of a nuclear reactor fuel assembly is enhanced by increasing the crush strength of the zircaloy spacer grids which locate and support the fuel elements in the fuel assembly. Increased resistance to deformation as a result of laterally directed forces is achieved by increasing the section modulus of the perimeter strip through bending the upper and lower edges thereof inwardly. The perimeter strip is further rigidized by forming, in the central portion thereof, dimples which extend inwardly with respect to the fuel assembly. The integrity of the spacer grid may also be enhanced by providing back-up arches for some or all of the integral fuel element locating springs and the strength of the fuel assembly may be further enhanced by providing, intermediate its ends, a steel seismic grid.

Abstract: A board of electrical insulating material has power conductors mounted on one side and work circuits mounted on the other side. A power source to actuate the work circuits is connected to the power conductors in a set sequence. Holes are provided through the board to receive conductive pins to electrically connect power conductors to work circuits to actuate each selected work circuit at a predetermined point in the set sequence.

Abstract: An automatic motion inhibit system for a nuclear power generating system for inhibiting automatic motion of the control elements to change the reactor power in response to turbine load changes. A final reactor power level setpoint is continuously compared with reactor power and a setpoint-greater-than-power signal is generated when the final reactor power level setpoint is greater than the reactor power. The final reactor power level setpoint is a setpoint within the capacity of a steam relief valve system which in no event is lower in value than the lower limit of automatic operation of the automatic motion control means. Also the reactor power demand or turbine load is continuously compared with a predetermined power demand threshold and a demand-less-than-threshold signal is generated when the reactor power demand is less than the demand threshold.

Abstract: A stem generator with its sections arranged for the limited space available in a marine installation. The heated surfaces are exposed to both the products of combustion of original fuels and the discharge from the prime movers of marine propulsion. The water being vaporized is positively pumped up through the heated surfaces to the short length upper steam separator drum. The superheat surfaces are arranged in modular form so they may be readily replaced and can also be drained of collected liquid when maintenance is required.

Abstract: A primary element is connected to a control element of a fluid pressure relay to move the element to positions at which fluid pressure outputs of the relay will be generated to represent the positions.

Abstract: A device for discriminating between the presence of flame in a selected position and the presence of flame in nearby locations within a combustion area is disclosed. A means for detecting electromagnetic radiation having wavelengths known to be characteristic of the base of the flame but not of the rest of the flame is aimed at the position at which the base of the flame to be monitored will occur if the flame is present. The intensity of the radiation having the given wavelengths is compared with the intensity of radiation having nearby wavelengths, and the relative magnitudes of the two intensities are used as an indication of whether flame is present or absent at the selected position.

Abstract: Pipe insulating units are disclosed which can be slipped radially over the pipe. The units are formed such that two adjacent pieces interlock to form a set which completely surrounds the pipe and which has parallel faces which are abutted by the parallel faces of adjacent sets. The units and sets are then held together by bolting or other means. Each unit comprises a circular piece of insulating material having a hole in the center thus forming an annular disc. This annular disc has a portion of the annulus omitted with this omitted portion having sides which are parallel to each other and which are tangent to the periphery of the hole in the center. The sides of this omitted portion extend outwardly to the periphery of the disc. Formed integrally therewith on one face of the disc is an outwardly extending portion in the area bonded by extensions of the parallel sides of the omitted portion and on the opposite of the center hole from the omitted portion.

Abstract: An air quality control system scrubs flue gas of SO.sub.2 and particulates with a slurry of lime/limestone and water. The system includes a tank below the contact of gas and slurry in which the chemical action is completed and from which the slurry is recirculated to the scrubber. A bubbler system is connected to the reaction tank to detect the density of the slurry and monitor or control the density. The bubbler system is supplied the liquid and dissolved solids decanted from the thickener to which the slurry is drawn for disposal.

Abstract: An apparatus for compensating for line voltage variations in a pulsed welding arc supply. A circuit for drawing a current that is proportional to that part of the supply voltage in excess of a predetermined reference is drawn from the capacitor charging circuit in a UJT triggering device. Thus, the more the line voltage exceeds the desired level, the greater is the compensating current withdrawn from the capacitor charging circuit. As a result, the average welding current remains at the desired level despite supply-voltage variations.

Abstract: An apparatus is disclosed for realizing analog signal filters with very long time constants. In order to avoid the losses inherent in conventional energy-storage devices such as capacitors and inductors, an analog signal is converted into digital form for storage, thereby eliminating losses, and the digital quantity is continuously converted back to analog form for use in the analog circuit.

Abstract: An automatic motion inhibit system for a nuclear power generating system for inhibiting automatic motion of the control elements to reduce reactor power in response to a turbine load reduction. The system generates a final reactor power level setpoint signal which is continuously compared with a reactor power signal. The final reactor power level setpoint is a setpoint within the capacity of the bypass valves to bypass steam which in no event is lower in value than the lower limit of automatic control of the reactor. If the final reactor power level setpoint is greater than the reactor power, an inhibit signal is generated to inhibit automatic control of the reactor.

Abstract: An improved core servicing apparatus for a nuclear reactor having a vessel, a head for the vessel, one or more penetration openings in the head and a core within the vessel of the type having an array of fuel assemblies and including apertures in the array for neutron absorbers. The servicing apparatus includes a support column adapted to be supported by and depend from the head in registry with a penetration opening; a plurality of core servicing elements which may include neutron absorber actuating means and/or instrument packages are supported by the support column; and means are provided for laterally displacing at least some of the servicing elements relative to the support column between a laterally compact and a laterally expanded configuration.In one embodiment, instruments may be located at the lower end of long resilient cables and are longitudinally movable within and beyond guide channels supported by the support column.

Abstract: A pouring ladle for pouring molten metal into molds or other containers, including wall structure forming a chamber for holding the molten metal, a spout having wall structure forming longitudinal passage means therein, the passage having an inlet end in fluid communication with a chamber and an outlet end through which molten metal can be discharged, a drive gear arrangement is provided for rotating the pouring ladle about an axis of rotation, positioned such that the axis of rotation passes through the center of the discharge end of the passage, and the pouring ladle and spout being constructed such that the lower outer surface of the wall structure forming the chamber and the lower outer surface of the wall structure of the spout lie in the same horizontal plane when the ladle is in its full, non-pouring position. Thus, the entire ladle can be positioned above the mold while it is being filled with molten metal, or while the ladle is being moved to the pouring position.