Abstract: An electromagnetic pump for molten metals wherein a rotating magnetic field causes rotation of the molten metal about the axis of the pump structure. A swirl inducer at the inlet end of the pump has inlet passageways radially spaced from the axis of the pump so as to induce rotational flow in the molten metal passing therethrough.A dual-conical shaped inductor supported within and axially aligned with a molten metal passageway forms in combination with said passageway a conically tapered flow path for the molten metal.Angularly oriented flutes are provided in the region of the inductor periphery within the vicinity of the largest diameter portion thereof in order to convert the rotational flow of the molten metal back into axial flow for discharge from the pump.

Abstract: A position selection system comprising a map of a plurality of selection positions arranged in columns and rows with a normally unenergized light emitter and a respective normally disabled light detector positioned at opposie ends of each of the columns and rows. The light emitters are sequentially energized and the respective light detectors are synchronously sequentially enabled to thereby avoid the necessity of collimating light from the light emitters.

Abstract: A nuclear fuel element for use in the core of a nuclear reactor is disclosed and has an improved composite cladding comprised of a moderate purity metal barrier of zirconium metallurgically bonded on the inside surface of a zirconium alloy tube. The metal barrier forms a shield between the alloy tube and a core of nuclear fuel material enclosed in the composite cladding. There is a gap between the cladding and the core. The metal barrier forms about 1 to about 30 percent of the thickness of the composite cladding and has low neutron absorption characteristics. The metal barrier serves as a preferential reaction site for gaseous impurities and fission products and protects the alloy tube from contact and reaction with such impurities and fission products. Methods of manufacturing the composite cladding are also disclosed.

Abstract: Alloys reacting with water, water vapor and reactive gases at temperatures in the range of about 200.degree. to about 650.degree. C. have the essential components of nickel, titanium and zirconium. The alloys can be made by arc melting zirconium, nickel and titanium and can be formed into sheet or foil by inert-atmosphere hot rolling. The alloys can also be made by plating nickel on a sheet of zirconium-titanium alloy and then conducting a diffusion process by heating the plated alloy in vacuum.

Abstract: The invention is directed to a supervisory circuit for a control system of the type having a plurality of redundant input channels and a single output channel. More specifically, the invention is directed to a supervisory circuit for a two-channel redundant control system that provides reliability approaching that of a three-channel system. The supervisory circuit operates on the assumption that the majority of control circuit failures are catastrophic. The supervisory circuit includes a channel select circuit that receives the outputs of both of the identical control circuits and determines the faulted channel. Determination of the faulted channel is accomplished by a two-step comparison. In the first step, the outputs of both channels are compared with a previously stored output, or average of previous outputs. In the second step, signals representative of the absolute difference between each channel output and the stored output are compared.

Abstract: A method for monitoring and controlling the operation of a dual platen press used in the manufacture of nuclear fuel pellets is disclosed. The method comprises the steps of indicating the displacements of both platens and imposing the displacements of the platens on orthogonal axes such that the displacements jointly control the motion of a point which traces a lissajous figure representative of the displacement and relative velocity of the press platens. A second lissajous figure representing the desired platen movements and relative velocity may be superimposed on the first lissajous figure, differences between the first and second lissajous figures indicating deviations from the desired operation of the press. Alternately, a press operator may simply use the first lissajous figure constructed from the actual platen displacements to analyze the operation of the press. The completion of preselected portions of the first lissajous figure may be detected and used to trigger subsequent press operations.

Abstract: A readily transportable device of relative light weight comprising a pair of tensioned guides for providing accurate and stable reference planes. An embodiment comprises a pair of rods or guides in tension between a pair of end members, the end members being spaced apart by a compression member. The tensioned guides provide planes of reference for measuring devices moved therealong adjacent a component to be measured. The device is especially useful for making on-site dimensional measurements of components, such as irradiated and therefore radioactive components, that cannot readily be transported to an inspection laboratory.

Abstract: Remotely manipulatable probe and apparatus for positioning a corrosion thickness sensing transducer over selected areas of the internal surface of a tubular radioactive component submerged in a pool of water for radiation shielding.

Abstract: Apparatus for monitoring and controlling the operation of a dual platen press used in the manufacture of nuclear fuel pellets is disclosed. The apparatus includes means for indicating the displacements of both platens and imposing the displacements of the platens on orthogonal axes such that the displacements jointly control the motion of a point which traces a lissajous figure representative of the displacement and relative velocity of the press platens. A second lissajous figure representing the desired platen movements and relative velocity may be superimposed on the first lissajous figure, differences between the first and second lissajous figures indicating deviations from the desired operation of the press. Alternately, a press operator may simply use the first lissajous figure constructed from the actual platen displacements to analyze the operation of the press. The completion of preselected portions of the first lissajous figure may be detected and used to trigger subsequent press operations.

Abstract: A process for recovering compounds of enriched nuclear fuel from scrap materials is disclosed. The process yields an acid solution with the nuclear fuel dissolved therein. Except for spent filter media, the scrap materials are calcined to produce an oxidized material, which is reduced to a particulate material and leached in an acid bath that contains some recycled acid to yield an acid solution of the nuclear fuel material. The scrap materials comprised of spent filter media are mulched and contacted with the acid solution. The insoluble materials are separated from the acid solution, and at least a portion of the acid solution is recycled to the leaching step, while the remainder of the acid solution is collected for subsequent treatment to recover the dissolved nuclear fuel material. Apparatus for performing the foregoing process is also disclosed.

Abstract: Apparatus for remotely testing radioactive components, for example, the components of a nuclear reactor, by determining and recording the neutron transmission characteristics of the component.

Abstract: A mixture of powders, preferably UO.sub.2 powders, is blended to complete homogeneity in a nuclear-safe, bubbling-bed fluidized bed blender. The blender includes a generally vertically-oriented, slab-shaped, nuclear-safe mixing vessel having a fluidizing grid disposed on the bottom of the vessel. The fluidizing grid comprises a linear array of generally downwardly-directed pyramidal-shaped hoppers each having walls converging into a conically-shaped closable opening. A plurality of gas orifices is provided for directing a flow of fluidizing gas downwardly into the bottom of each of the hoppers and fluidizing gas is supplied to the orifices at a velocity sufficient to cause bubbles of fluidizing gas to rise through and emerge from the mixture of UO.sub.2 powders until a homogeneous blend of solid UO.sub.2 powders is achieved. The apparatus eliminates dead-zones normally present near the bottom of prior art fluidized bed blenders.

Abstract: A mixture of fine and cohesive powders is blended to complete homogeneity in a nuclear-safe bubbling-bed fluidized bed blender having an improved fluidizing grid. The blender includes a generally vertically-oriented slab-shaped, nuclear-safe mixing vessel having a fluidizing grid disposed at one end of the vessel. The fluidizing grid comprises a linear array of generally downwardly-directed, pyramidal-shaped hoppers each having walls converging into a conically-shaped opening. A plurality of ball valves are employed, one such valve being disposed at the bottom of each hopper. The rotary closure member of each of the ball valves includes a first set of gas orifices for directing a flow of fluidizing gas upwardly in a divergent swirl-shaped pattern along the walls of each of the hoppers. In one embodiment a second set of fluidizing gas orifices for directing a flow of fluidizing gas downwardly into the apex of each of the hoppers is also provided.

Abstract: In an arrangement for feeding a fluid at a given temperature into a vessel containing fluid at a different temperature from an inlet pipe through an inlet nozzle to feedfluid distribution means in the vessel, a removable thermal isolator arrangement is provided. Spaced concentric sleeves form a series of fluid spaces which thermally insulate the inner surface of the nozzle from the feedfluid and leakage feedfluid is directed away from the nozzle whereby thermal cycling of the inner surface of the nozzle is minimized to eliminate cracking thereof.

Abstract: An electrochemical device for measuring the concentration of oxygen in liquid alkali metal is described. Such device includes an elongated probe tube which is designed to be inserted into the liquid alkali metal whose oxygen content is of interest. A cup of a solid electrolyte material is bonded to the tube adjacent its lower end so that the outside surface of its bottom wall is in intimate contact with the liquid metal. The cup contains a mixture comprising a known concentration of one of the free metals gallium, indium and tin, and an oxide of such metal. This mixture is liquid at the temperature of operation of the device and is in intimate contact with the inner side of the bottom wall of the cup to provide a reference electrode.

Abstract: The invention is directed to a method and apparatus for providing a single-cycle boiling moderator-coolant nuclear reactor which accommodates changes in demand with a turbine generator on direct governor control. Current single-cycle boiling moderator-coolant nuclear reactors employ turbine generators that are slaved to the reactor. This arrangement is dictated because of inherent response limitations of the single-cycle boiling moderator-coolant nuclear reactor. The system of the present invention diverts steam from steam consuming normal auxiliary plant equipment to maintain reactor pressure when a rapid increase in turbine power demand is made such as during a daily load following or a frequency regulation change in demand. This allows the turbine generator to be placed on direct governor control. Rapid positive or negative demands accepted by the turbine cause a decrease or an increase in the pressure of the reactor.

Abstract: Remotely manipulatable probe and apparatus for positioning a corrosion thickness sensing transducer over selected areas of the surface of a radioactive component submerged in a pool of water for radiation shielding.BACKGROUNDIn known types of nuclear power reactors, for example as used in the Dresden Nuclear Power Station near Chicago, Ill., the reactor core comprises a plurality of spaced fuel assemblies arranged in an array capable of self-sustained nuclear fission reaction. The core is contained in a pressure vessel wherein it is submerged in a working fluid, such as light water, which serves both as coolant and as a neutron moderator. Each fuel assembly comprises a removable tubular flow channel, typically of approximately square cross section, surrounding an array of elongated, cladded fuel elements or rods containing suitable fuel material, such as uranium or plutonium oxide, supported between upper and lower tie plates.

Abstract: A process control system providing a particular control effort function is divided into a primary control effort portion having a primary controller, and a feed back from the controlled process to the primary controller, and a secondary control effort portion having a secondary controller in controlling relation therewith, and receiving its control input from the primary controller. The secondary controller is provided with limits such that it becomes saturated in operation, thereby permitting selective overriding by the primary controller, while utilizing the secondary controller and actuators the maximum practical amount. The arrangement is suitable for use with continuously variable devices or for use with on-off (bang-bang) devices. The particular embodiments illustrated are (1) a bang-bang heater system, and (2) a continuously variable fluid flow control system.

Abstract: A method of determining the oxygen content of a liquid metal is disclosed and comprises measuring the EMF across an electrolytic cell in which one of the electrodes comprises the liquid metal and the other electrode is a reference electrode of a mixture comprising a known concentration of one of the metals selected from the group of gallium, indium and tin, and an oxide of said metal with the mixture being liquid at the temperature of measurement, and the electrolyte is an oxygen ion conductive, solid electrolyte body wall having a pair of opposite side surfaces with the first one of said surfaces being in intimate contact with the liquid and the other one of said surfaces being in intimate contact with said reference electrode.

Abstract: A process for fabricating a body of a nuclear fuel material has the steps of admixing the nuclear fuel material in powder form with a binder of a compound or its hydration products containing ammonium cations and anions selected from the group consisting of carbonate anions, bicarbonate anions, carbamate anions and mixtures of such anions, forming the resulting mixture into a green body such as by die pressing, heating the green body to decompose substantially all of the binder into gases, further heating the body to produce a sintered body, and cooling the sintered body in a controlled atmosphere. Preferred binders used in the practice of this invention include ammonium bicarbonate, ammonium carbonate, ammonium bicarbonate carbamate, ammonium sesquicarbonate, ammonium carbamate and mixtures thereof.