Abstract: A preventive maintenance method and apparatus for a structural member in a reactor pressure vessel according to the present invention reduce a tensile residual stress on a surface of the structural member by impinging a water jet from a nozzle onto a plane surface of a deflector to thereby change direction of flow of the water jet, and impinging the water jet after being deflected onto the surface of the structural member. This method and apparatus are applicable to a narrow space portion, and can improve a residual stress on the surface of the structural member and can also prevent damage such as stress corrosion cracking.

Abstract: A combustion activated tool includes a housing having a longitudinal bore that extends and connects with a vertical bore, a piston and piston guide disposed within the longitudinal bore and moveable axially therein, and an advance lever having a reset end and an advancing end, the lever disposed on a pivot skew to the axis of the longitudinal bore, the lever having an axis essentially parallel with the longitudinal bore, the advancing end of the lever attached on an arm of the lever angled to one side of the axis of the longitudinal bore and effective to engage teeth on the side of a strip of charges disposed in the vertical bore, the reset end of the lever being disposed on the same side of the axis of the longitudinal bore engaging the piston guide along an edge of the lever.

Abstract: A fuel assembly mechanical flow restriction apparatus for detecting failure in situ of nuclear fuel rods in a fuel assembly during reactor shutdown.

Abstract: The boron concentration can be measured without intervention into the cooling circuit of a nuclear power station. A mobile emitter and a mobile receiver are provided, with the interposition of at least one coolable region, for placement on a coolant-carrying component of the cooling circuit.

Abstract: In a nuclear reactor, in-core stability is improved, power density is increased, and an economical natural-circulation reactor (or partial forced-circulation reactor) is achieved. The reactor core has a void reactivity coefficient between −0.07 and −0.03% &Dgr;k/k/% void fraction. This void reactivity coefficient range is achieved by, for example, the design of the by-pass portion and channel box, the enrichment distribution along the axial direction, the provision of blanket areas, and/or the arrangement of water rods and fuel rods within a channel box.

Abstract: A preventive maintenance method and apparatus for a structural member in a reactor pressure vessel according to the present invention reduce a tensile residual stress on a surface of the structural member by impinging a water jet from a nozzle onto a plane surface of a deflector to thereby change direction of flow of the water jet, and impinging the water jet after being deflected onto the surface of the structural member. This method and apparatus are applicable to a narrow space portion, and can improve a residual stress on the surface of the structural member and can also prevent damage such as stress corrosion cracking.

Abstract: In a system for monitoring power of a nuclear reactor, a plurality of neutron flux measuring devices are arranged in a reactor core of the nuclear reactor for measuring neutron flux so as to generate neutron flux signals on the basis of the measured neutron flux. The neutron flux signals are filtered through a first weighting coefficient and a second weighting coefficient previously held in a monitoring signal calculating unit so as to generate stability monitoring signals. The first weighting coefficient corresponds to a fundamental mode of a neutron flux distribution in the reactor core and tire second weighting coefficient corresponds to a higher mode of the neutron flux distribution therein. The stability monitoring signal filtered through the first and second weighting coefficients are transmitted to a stability monitoring unit the stability monitoring unit monitors the stability of the core according to the transmitted stability monitoring signals.

Abstract: In each of a number of fuel assemblies loaded in a core of a boiling water reactor, a fuel holding portion of a lower tie plate holds lower end portions a plurality of fuel rods and at least one water rod. The water rod includes a rising pipe opened to a space in the lower tie plate below the fuel holding portion and introducing upward a coolant introduced to the rising pipe, and a falling pipe communicated with the rising pipe and introducing downward the coolant introduced through the rising pipe. The falling pipe has a coolant outlet opened to a second coolant passage defined between the fuel rods above the fuel holding portion. The rising passage is filled with the coolant during a period of rated power operation of the reactor, and a surface of the coolant is formed in the rising pipe during a period of non-rated power operation in which a flow rate of the coolant supplied to the fuel assemblies is lower than that during the period of rated power operation.

Abstract: A tool kit for adjusting the angular orientation of water rods about respective axes in a nuclear fuel bundle includes a washer wrench, socket, orientator wrenches, orientator gauges and an orientator cap. The washer wrench has opposed jaws having parallel surfaces and reliefs at junctures between the surfaces and the base of the jaws to inhibit rounding off corners of tie bars connected to the water rods. The socket has a corresponding D-shaped recess as the tie bar ends to facilitate rotational adjustment thereof. Orientator wrenches have witness notches for aligning the flats of the tie bars. The orientator gauges comprise a series of gauge bodies each having a pair of axially parallel openings with stepped margins to the openings such that one opening is axially offset from the margin defining the entrance to the other opening.

Abstract: A fuel assembly for a boiling water reactor comprising a plurality of fuel units (3a, 3b, 3c, 3d), stacked on top of each other, each one comprising a top tie plate (5), a bottom tie plate (6) and a plurality of fuel rods (4a, 4b, 4c) arranged between the top tie plate and the bottom tie plate. The fuel units are surrounded by a fuel channel (9) with a substantially square cross section. At least some of the fuel units comprise fuel rods with different diameters and different fuel quantities. The fuel rods are adapted such that fuel quantity and lattice space are optimized laterally and axially in the fuel assembly.

Abstract: Extruded Borated Aluminum rodlets of extended length are formed to maximize neutron absorption surface area while minimizing weight. They are located in the empty cells of a new or spent fuel assembly previously used by control rods and instrumentation with a length equal to that of a fuel rod or guide tube and control the reactivity of the fuel assembly during storage and shipment of the spent fuel assembly.

Abstract: A mounting system for a cylindrical object such as a spotting rifle is provided. First and second U-shaped brackets are coupled to a base such as a launching device. Each U-shaped bracket has first and second legs extending from a common base. The two U-shaped brackets are oriented such that the first and second legs of one U-shaped bracket are perpendicular to the first and second legs of the other U-shaped bracket. Each U-shaped bracket slidably receives a sleeve between its first and second legs. Each sleeve is attachable to the bracket's common base such that the position of the sleeve relative to the bracket's common base is adjustable. A locking mechanism is provided with each U-shaped bracket/sleeve combination to lock the sleeve laterally between the first and second legs of the U-shaped bracket. The two sleeves are coaxially aligned.

Abstract: A spacer of a fuel assembly having intersecting webs undergoes reduced longitudinal expansion as a result of corrosion during an operating period. The webs have intersection locations at which assembly gaps are provided. The assembly gaps have widths which correspond essentially, at most over a fraction of their total length, to the wall thickness of an intersecting web, but are wider in a remaining region. Since corrosion layers growing from an edge of an assembly gap toward the intersecting web cannot touch the web, no solid pressure, which could lead to longitudinal expansion, builds up.

Abstract: A locking device for use in restraining a jet pump downcomer of a nuclear reactor, including an upper jaw; a lower jaw placed in an opposing position below the upper jaw; and a tightening screw movably supporting the upper jaw and the lower jaw. When installed on a jet pump downcomer, the complete assembly includes a restraining ring; a downcomer carried by the restraining ring; a wedge supported by the restraining ring and the downcomer; and a guide bolt extending in an axial direction in relation to the downcomer such that the wedge is movably supported by the guide bolt. The wedge is interposed between the upper jaw and the lower jaw, and one end of the upper jaw and a corresponding end of the lower jaw are moveably supported by the guide bolt. The upper jaw and lower jaw are supported at their respective opposite ends by the tightening screw.

Abstract: A revolver-lock device including a positive means, for locking of the bullet cylinder, a lock-housing for containing lock mechanism components, an extension rod, an inner permanent magnet, an extension spring, a multiple number of balls or similar members, a housing sealing disc, an external magnet key with slot, means for preventing retraction of the locking expansion balls from the cylinder walls, for preventing insertion of bullets into the cylinder holes, and for preventing the cylinder from rotating, and thus operation of the trigger, hammer and firing pin, means for restricting the bullet firing caps to be off-line with the firing pin, means for preventing the revolver cylinder from being opened for loading, a method for high volume, low cost production due to simplicity of design, a quick activating/deactivating means for fast use of the revolver, a compact size and shape which allows easy casing of the revolver, a parts interchanging feature for similar revolvers of the same caliber and for different

Abstract: A passive pulse generator can be connected to a line in order to activate a safety fitting in a nuclear power plant. The line can be closed by a closure element. In the event of a temperature change in the vicinity of the pulse generator, the closure element is actuated solely as a result of a thermal volume change of an actuating element, so that the line is released. The pulse generator therefore activates the fitting passively, without additional control pulses. A method for activating a fitting with a passive pulse generator is also provided.

Abstract: A telescope apparatus and system for rifles and other weapons comprising a forward portion, consisting of a forward objective lens fixed on the front end of a firing line light tube, held firmly to the weapon by slip springs in which the forward light tube may be rotated, and/or a side optics system extending perpendicular to the rear of the forward portion of the telescope may be turned and locked on the forward portion, so that the side optics system of the telescope, extending a preferred distance to the side of the weapon, may be positioned and fixed at the preference of a person, forward or back and on the left or right side of the weapon, or other preferred positions, and aimed by a person sighting through the viewing lens system of the telescope at the end of the side optics system, using conventional, manual aiming devises and/or aiming the weapon by means of electronically controlled laser aiming devises, together with attachable range finding and other devises.

Abstract: The service life of gun barrels of firearms with a high cyclic rate can be extended by means of the cooling device of the invention. To this end, coolant (7) is conveyed from a reservoir (6) into a pressure cylinder (10) by drawing up a hydraulic cylinder (13), while the feed line (14) to the gun barrel is closed. Thereafter the hydraulic piston (13) is moved in the opposite direction by a pressure reversal and the coolant (7) in the pressure cylinder (10) is placed under a defined operating pressure. Prior to triggering a volley, the feed line (14) is opened, so that the coolant (7) can flow via the feed line (14) and the nozzle (16) to the gun barrel (1). The coolant (7) is pushed back by the gas pressure respectively being created when a shot is fired, and following the lowering of the gas pressure to the operating pressure, it is again injected into the gun barrel (1).

Abstract: The present invention provides a rear gun rest that can be attached to a stock of a firearm in a permanent fashion. The rear gun rest remains on the firearm with minimal interference with the use of the firearm. The rear gun rest includes a main tube pivotally connected to said stock. The main tube includes a pivot pin as part of the main tube, a retaining pin as part of the main tube and at least one tension spring connected between said pivot pin and said retaining pin. The pivot pin allows the pivoting of the main tube. The tension spring aids in retaining the main tube in a desired position. The rear gun rest also includes an extension tube and a fine adjustment rod for adjusting the height of the stock. The extension tube is extendible from the main tube. The fine adjustment rod is extendible from the extension tube.

Abstract: The present invention is a device that, when used properly, is useful for increasing the safety of firearms. In one embodiment, the present invention comprises a threaded aperture located in a rear position of a firearms' trigger, toward the handle. The preferred location of the aperture is located close to an upper rear corner of an exposed surface of the trigger. Inserted into the threaded aperture is a complementarily threaded barrel screw. The screw has a special keyed head. The special key configuration of the head prevents curious children from inadvertently reversing the safety mechanism. In a preferred embodiment, the keyed head has a pentagonal shaped indentation and generally centered within the indentation is an outwardly projecting guide pin. When the screw has been inserted into the aperture, there are two function positions. In a use position, the screw is contained in the trigger and does not substantially project from the trigger.