Abstract: A locking assembly for a firearm, such as a semiautomatic or fully automatic pistol, includes a support member with an action locking arm and an action locking lug extending from a first end of the support member and a retainer arm extending from a second end of the support member. The action locking lug and arm are received in the firing chamber of a pistol, while the muzzle end of the pistol is rested on the retainer arm. A recoil spring in the pistol generates a pincer action between the action locking arm and the retainer arm to securely maintain the pistol in the locking assembly, preventing withdrawal with the normal upward movement. The action locking arm and lug positively prevent operation of the pistol trigger and prevent accidental chambering of an ammunition round. The pistol may be deployed with one downward thrust on the pistol grip, compressing the recoil spring and providing clearance for removal of the action locking arm and lug.

Abstract: A nuclear spectroscopy method and apparatus for obtaining qualitative and quantitative information related to water flow, comprising the steps of:(1) irradiating the water flow with a source of neutrons of sufficient energy to interact with oxygen atoms in the water according to the activation reaction O.sup.16 (n,p)N.sup.16 ;(2) detecting and counting, with at least at a detector, the gamma rays emitted during disintegration of N.sup.16 ;(3) making a plot of the counts versus time; and(4) deriving from said plot information related to said water flow.The irradiating is advantageously interrupted after a given period of time, and is preferably immediately followed by the detection. The water flow velocity "V" is calculated from the formula V=d/t, where "d" is the distance between the source and the detector(s), and "t" is the time period between the irradiation and the time corresponding to a characteristic on said plot, representative of the water flow and departing from the N.sup.16 exponential decay curve.

Abstract: A fuel assembly of a pressurized water nuclear reactor includes at least two fuel rods, respectively, having a cladding tube of given outer and inner diameters and pellets of given outer diameter received in the cladding tube, the fuel rods being disposed in the fuel assembly at a given mutual spacing of center points thereof, a ratio of the given mutual spacing of the center points of the fuel rods to the outer diameter of the cladding tube being in a range between 1.35 and 1.37.

Abstract: A corrosion resistant zirconium alloy is comprised of, in weight percent, about 0.1 to less than 0.5 percent bismuth, about 0.1 to less than 0.5 percent niobium, and the balance substantially zirconium. Preferably, niobium is about 0.1 to 3 weight percent. The alloys have improved corrosion resistance as compared to the moderate-purity sponge zirconium while maintaining a ductility comparable to sponge zirconium.

Abstract: A mixing grid for use in a pressurized reactor comprises at least two sets of crossed fixed together at their cross-points, delimiting cells, some for receiving fuel rods and the others for receiving guide tubes, the plates being provided with coolant stirring fins extending the plates downstream and disposed to deflect the coolant transversely to its general flow direction, each plate being provided with abutment means projecting inwardly from each of the faces of the cells for receiving fuel rods, thereby delimiting a passage that is larger than the size of the rods but small enough to prevent a rod contained in the cell coming into contact with the fins. In each wall the abutment means comprise two portions of plate that are cut out and deformed into a scoop-shape, and that are offset relative to each other in the coolant flow direction, with the scoops projecting in opposite directions and tending to cause coolant to pass from one cell to another.

Abstract: The lower end nozzle (1) comprises an adaptor plate (2), supporting feet (3) and a particle retention device (6) consisting of a filter plate pierced with holes and attached to the bottom face of the adaptor plate (2) over a substantial portion of its surface.

Abstract: Particulates from a source fall into a tundish which discharges to a collection chamber. The build-up of particulates in the chamber is sensed, and a valve opened at the bottom of the chamber when a pre-determined level of the particulates is sensed in the chamber. A valve at the top of the chamber may be closed at the same time so that pressurized air can be injected into the chamber to expel the particulates through the bottom of the chamber through the valve. A filter circuit may be connected to the tundish to assist in removing particulates from the tundish.

Abstract: A gas cooled nuclear fuel element. A cylindrical tube having an open lower end contains nuclear fuel disks stacked one upon the other to define an annular space between the tube and disks. An upper and a lower end fitting in the tube support the stack of fuel disks. Each disk has an axial bore or channel for coolant flow. The disks may also be provided with grooves extending radially on the upper or lower face from the axial channel to the outer edge of each disk. The lower end fitting has a central bore that is coaxial with the axial channel in the disks. Coolant flows into the annular space, radially between disks, and then axially out the disks and lower end fitting.

Abstract: So as to position a device, such as an eddy current probe support inside a cylindrical cavity with radial perforations opening into said cavity, a device (36) is proposed, said device including a pole (50) orientated parallel to the axis of the cavity. This pole may occupy different pre-established indexing positions in rotation and in translation inside the cavity by means of a mechanism (42, 44, 54, 58, 60). In each of these indexing positions, an active head (98), mounted at the extremity of the pole (50) by means of a pantograph (66) and a cladding arm (100), is able to move in a specific active zone on the lower wall of the cavity. To this effect, the active head is clad by the arm (100) and is equipped with autonomous thrustors controlling its movement.

Abstract: A method of decontaminating radio nuclide-contaminated corrosion products, which are sparingly soluble in acid, from primary system surfaces in reactors of the pressurized water reactor type and the boiler reactor type with hydrogen dosage and similar, by oxidation and concurrent dissolution in an acidic decontamination solution of the acid soluble corrosion products obtained by said oxidation. The characteristic feature of the method is that said oxidation is performed with Ce.sup.4+ ions, ozone and chromic acid in the presence of perhalogen acid, preferably perchloric acid, at a pH below 3.