Abstract: Cladding for nuclear fuel elements which is formed with a zirconium metal barrier layer bonded to the inside surface of a zirconium alloy tube and which is sized by a cold working tube reduction process and is heat treated after final reduction at a temperature and for a time period which allows substantially complete recrystallization of the zirconium metal barrier layer and provides a fine-grained microstructure therein and which stress-relieves but does not fully recrystallize the zirconium alloy tube. The crystallographic structure of the zirconium metal barrier layer may be improved by compressive deformation such as shot-peening.

Abstract: A remotely operable device for cutting sample pieces from the walls of an irradiated component while the component is submerged in a pool of water to shield the operator from radiation.

Abstract: A process for imparting increased strength and physical durability in green bodies or pellets formed of particulate oxides of uranium, plutonium and the like in the production of pelletized fissionable nuclear fuel. The green or unfired pellets comprise a fugitive binder dispersed through the particulate oxide fuel material.

Abstract: A device for sealing a gateway between interconnectable pools in a nuclear facility comprising a frame supporting a liquid impermeable sheet positioned in a U-shaped gateway between the pools. An inflatable tube carried in a channel in the periphery of the frame and adjoining the gateway provides a seal therebetween when inflated. A restraining arrangement on the bottom edge of the frame is releasably engagable with an adjacent portion of the gateway to restrict the movement of the frame in the U-shaped gateway upon inflation of the tube, thereby enhancing the seal. The impermeable sheet is formed of an elastomer and thus is conformable to a liquid permeable supportive wall upon application of liquid pressure to the side of the sheet opposite the wall.

Abstract: A hydrogen sensing device for determining the concentration of hydrogen in a fluid atmosphere consists of a sealed chamber formed with a window which selectively allows diffusion of hydrogen into the chamber. Alpha particles from a source contained in the chamber ionize the hydrogen and a pair of polarized electrodes collect the resulting electrons to provide a current which is a function of the hydrogen concentration in the chamber. A second window permeable to helium allows escape of the helium from the chamber that is formed by the combination of electrons with alpha particles therein.

Abstract: An underwater suction device for collecting irradiated materials in a pool of water. The device includes injection and suction tubes and a removable, disposable filter for capturing irradiated materials. Pressurized water is injected into the suction tube through a jet pump nozzle to establish a suction flow through the tube. The suction device is manually positionable by an operator standing at a dry location and extending the device underwater by maneuvering a positioning pole. The pole is pivotally connected to the injection or suction tube by a variably positioning latching mechanism.

Abstract: Advantage is taken of the non-uniform axial neutron flux density distribution in a nuclear reactor core by using fuel rod spacers of low neutron absorption in high neutron flux density regions and fuel rod spacers of low coolant flow resistance in the lower neutron flux density regions of the core, this spacer combination also providing higher fuel bundle thermal limits.

Abstract: Typical nuclear fuel material contains tramp ferromagnetic particles of random size and distribution. Also, selected amounts of paramagnetic or ferromagnetic material can be added at random or at known positions in the fuel material. The fuel material in its nonmagnetic container can be scanned by magnetic susceptibility change detecting apparatus to provide a unique signal waveform of the container of fuel material as a signature thereof. At subsequent times in its life, the container similarly can be scanned to provide subsequent signatures. Comparison of the signatures reveals any alteration or tampering with the fuel material.

Abstract: A critically safe container for the storage and rapid discharge of enriched nuclear fuel material in powder form is disclosed. The container has a hollow, slab-shaped container body that has one critically safe dimension. A powder inlet is provided on one side wall of the body adjacent to a corner thereof and a powder discharge port is provided at another corner of the body approximately diagonal the powder inlet. Gas plenum for moving the powder during discharge are located along the side walls of the container adjacent the discharge port.

Abstract: Braking of the motion of a fluid-actuated drive is provided by a buffer arrangement which is normally sealed to prevent vaporization of the fluid in a buffer cylinder and which isolates the drive piston rings from braking pressures.

Abstract: Nuclear fuel for use in nuclear reactors is provided in the form of a nuclear fuel element with an interior barrier layer interposed between the sheath and the fuel. The barrier layer incorporates particles of copper in finely divided form to provide by combination with cadmium, which is released during irradiation of the fuel, a stabilized copper-cadmium compound localized intermediate the fuel and the sheath, thus impeding attack on the sheath by the released cadmium. There is further provided a simple, low cost method for applying the barrier layer in a nuclear fuel element.

Abstract: A fuel assembly for a nuclear reactor including a plurality of fuel rods held in spaced, parallel position between upper and lower tie plates and retained in lateral position by intermediate spacers and having a water tube in lieu of a fuel element in one or more of the rod positions, the water tubes having an outside diameter greater than that of the fuel rods and the spacer springs in the spacer cells of the water tubes being modified to accommodate the larger diameter of the water tubes.

Abstract: In the processes of nuclear fuel manufacture, scrap material such as uncontaminated reject powder and reject pellets, which would previously have been reprocessed chemially in conversion of the uranium values by dissolution into liquid form, is now mechanically reduced by crushing in a substantially inert atmosphere and converted to a slurry having between about 70 to 85 weight per cent solids, and then attrition milled utilizing scrap sintered UO.sub.2 pellets as the reducing medium. Grinding swarf generated during the centerless grinding of UO.sub.2 pellets may also be recycled provided it is sufficiently pure.

Abstract: Fixed ammonia in an aqueous stream is converted to free ammonia in solution by mixing the stream with a lime slurry in a mixing zone. The resulting liquid mixture is heated by contact with steam-containing gas to a temperature of at least about 95.degree. C. to form a heated liquid mixture containing free ammonia in solution and an ammonia-rich product vapor. A portion of the heated liquid mixture is withdrawn and is contacted with steam in a packed stripping zone to produce liquid waste and vapor containing free ammonia and steam. At least a portion of the vapor from the stripper is used as steam-containing gas for heating the liquid mixture. Ammonia is recovered from ammonia-rich product vapor withdrawn from the mixing zone.

Abstract: An apparatus incorporating a microprocessor control is provided for automatically loading nuclear fuel pellets into fuel rods commonly used in nuclear reactor cores. The apparatus comprises first and second elongated members having "V" troughs for alternately receiving a plurality of fuel pellets to be loaded alternately in first and second fuel rods. The pellets are weighed while in the "V" trough of each elongated member and each elongated member is alternately relocated in axial alignment with a cooperating fuel rod. A guide bushing assembly is provided to assist the transfer of the pellets from each of the elongated members into awaiting fuel rods. A rod handling assembly incorporating rod handling means, a thumper assembly to facilitate the loading of fuel pellets into the fuel rods, an adjustable fuel rod backstop and a rod carousel carrying a plurality of fuel rods, presents two fuel rods to the guide bushing assembly at the appropriate stage in the loading sequence.

Abstract: A method and arrangement for operating a boiling water nuclear reactor and fuel assembly designs for such reactor wherein the reactor is operated with uniquely located control rods that serve the primary functions of power shaping and reactivity control. A second and separate distinct group of control rods is withdrawn when the reactor is at power and the control rods of this group serve the primary function of reactor shutdown. The design of the fuel assemblies and the selected patterns of fuel assemblies and control rods make the separation of control functions feasible. The power shaping and reactivity control control rods are located in low power regions of the core designated control cells. The design of the fuel is such that the control rods of the control cells may remain in fixed positions in these cells during the operating cycle until withdrawal for burnup reactivity compensation.

Abstract: In a jet pump for a nuclear reactor a slip joint is provided between the mixer and diffuser sections thereof to facilitate jet pump maintenance and to allow thermal expansion. To limit leakage flow through the slip joint to a rate below that which causes unacceptable flow induced vibration of the pump, there is provided a labyrinth seal for the slip joint in the form of a series of flow expansion chambers formed by a series of spaced grooves in the annulus of the slip joint.

Abstract: A method is disclosed for preventing stress corrosion cracking or metal embrittlement of a zirconium or zirconium alloy container that is to be coated on the inside surface with a layer of a metal such as copper, a copper alloy, nickel, or iron and used for holding nuclear fuel material as a nuclear fuel element. The zirconium material is etched in an etchant solution, desmutted mechanically or ultrasonically, oxidized to form an oxide coating on the zirconium, cleaned in an aqueous alkaline cleaning solution, activated for electroless deposition of a metal layer and contacted with an electroless metal plating solution. This method provides a boundary layer of zirconium oxide between the zirconium container and the metal layer.

Abstract: A method is disclosed for controlling the release of radioiodine produced by the fission of uranium 235 during the process for the production of molybdenum 99. In the process for producing molybdenum 99, an aluminum-uranium alloyed target is irradiated with a neutron flux to bring about fission of the Uranium 235 producing molybdenum 99, radioiodine and other fission by-products. The method herein comprises reacting the irradiated target with a caustic solution. A reactive silver is then mixed with the caustic solution in an amount sufficient to react with substantially all of the radioiodine present in the caustic solution thereupon forming a silver precipitate of radioiodine. The precipitate formed is then separated from the caustic solution resulting in a substantially radioiodine-free caustic solution containing molybdenum 99.

Abstract: An accurately formed straight edge member serves as a track for a carriage movable along the length of an elongated component. Distance measuring devices supported by the carriage engage the adjacent surface of the component by which flatness, bow and twist of the component can be determined.