Abstract: Disclosed is a closure mechanism for sealing a nuclear waste disposal container. The mechanism allows partial closure of the container after internal apparatus have been inserted leaving a smaller opening for inserting and processing the waste material. Partial closure is achieved by inserting into the container an annular inner ring that fits against the container and by tightening an annular outer cap onto the inner ring, permitting access to the container through the aligned openings. After the waste material is loaded and processed, a sealing disk, axially joined to an inner plug to permit rotational but not linear movement, is passed through the outer cap opening and seats around the inner ring opening. The inner plug is tightened against the sealing disk by engaging matching threads on the inside of the outer cap opening.

Abstract: The disclosed negative ion source uses a solid-state element having a semiconductor portion, which source includes a region adapted to dissociate molecules of hydrogen or deuterium in said solid-state element by dissolution, another region adapted to convert the atoms generated through the dissociation of said molecules into negative ions as said atoms reach the proximity of surface of said solid-state element through diffusion process by resonance transition of electrons in said solid-state element and to liberate the thus produced negative ions from said surface by hot electrons in said solid-state element, wherein the dissociation, electronic resonance transition, and liberation continuously occur in succession.

Abstract: An accelerator-type neutron source employs a target, an ionization section and a replenisher for supplying accelerator gas. A positive voltage pulse is applied to the ionization section to produce a burst of neutrons. A negative voltage pulse is applied to the ionization section upon the termination of the positive voltage pulse to effect a sharp cut-off to the burst of neutrons.

Abstract: A nuclear reactor fuel assembly spacer grid having grid straps and a first type of spring clip. The grid straps define standard cells enclosing fuel rods and thimble cells enclosing control rod guide thimbles. The spring clip is bent to widthwise encircle a grid strap and has its two ends welded together. The first type of spring clip is used at a location on a grid strap having a standard cell and an adjacent thimble cell. The spring clip has a spring portion compressibly contacting the fuel rod in the standard cell. The spring clip also has a pair of separated flat portions straddling the control rod guide thimble in the thimble cell so as not to interfere with the guide thimble. The spring clip is made of a material having good radiation stress relaxation properties.

Abstract: The invention comprises a core barrel plug capable of being remotely installed in a port of a core barrel of a pressurized water nuclear reactor for converting the reactor from a by-pass downflow configuration to a by-pass upflow configuration. The plug comprises a body having an expandable cylindrical portion with a movable mandrel disposed in the body. Remote fluid pressurization causes the mandrel to be advanced thus expanding the body into contact with the port. The plug also comprises a locking mechanism to prevent inadvertent release of the plug and a venting mechanism to prevent inadvertent overpressurization of the plug.

Abstract: A closure in the form of a wedge-shaped member (3) to close the end of a container, such as a transport flask. The wedge-shaped member (3) carries a seal plate (7) which is urged by spring means (9) to project beyond the smaller end of the wedge-shaped member when the latter is in a position to open the end of the container. On advancing the wedge-shaped member (3) to close the end of the container the projecting end of the plate (7) first abuts against a stop (18) and continued advance of the wedge-shaped member relative to the seal plate (7) causes displacement of the seal plate towards the interior of the container to effect a seal at the end of the container.

Abstract: An apparatus for positioning an adjustable member as a function of a command signal and a control condition, especially for the positioning of a hoisting mechanism on a tractor or the like, comprises an operating circuit and a control circuit. The operating circuit has a bidirectional positionable valve with a valve side and first and second control devices for regulating flow of pressure medium from a supply tank to the adjustable member. The control circuit connects a control pressure medium source to the control devices at first and second junctions and includes adjustable throttles and a flow-regulating valve. A first adjustable throttle is connected between the supply tank and the first junction. The second adjustable throttle is connected between the control pressure medium source and the first junction and in series with the first adjustable throttle.

Abstract: A nuclear reactor system in which the neutron-energy spectrum is displaced towards lower energy (enthalpy) by a control selectively operable by commands outside of the reactor. The core of the reactor contains, in addition to fuel assemblies, sealed tubes filled with helium. The selective control of the neutron energy spectrum includes a master cylinder having a master piston. The master cylinder is immersed in the coolant and admits the coolant through a check valve. The admitted coolant serves as hydraulic fluid of the cylinder. When the external command to shift the neutron-energy spectrum is entered, the master piston compresses the coolant in the master cylinder. The compressed coolant flows into slave cylinders displacing their slave pistons. The slave pistons carry piston rods which drive rupturing tools into engagement with the tubes rupturing the tubes and admitting the coolant which is a neutron moderator and enhances the moderaton of the neutron energy.

Abstract: A hydraulic power system having a variable displacement hydraulic pump, a hydraulic motor driven by the hydraulic pump for actuating a load, with the pump and motor being connected to constitute a closed hydraulic circuit. A hydraulic servo controls the displacement volume of the pump, and a motor stop arrangement prevents, in its operative position, the motor from rotating. The system includes a control valve responsive to a main line pressure in the closed hydraulic circuit for controlling a hydraulic fluid supply to the hydraulic servo to prevent the main line pressure from substantially exceeding a predetermined level, and a control is responsive to the operation of the hydraulic servo for releasing the motor stop arrangement from the operative position when the hydraulic servo is operating.

Abstract: A control device for a hydrostatic gear driven by a drive engine, such as an internal combustion engine, with an auxiliary pump which is driven synchronously with the drive engine, to produce a control pressure which is adjustable via a control valve and which is dependent on the speed of the drive engine. The control device also has further a pressure reduction valve located in the control line, to remove or shut off the control pressure depending upon an external parameter. In order to make possible, with such a control device, both a partial pressure reduction and a complete pressure reduction by hydraulic means without the aid of sensitive control rods, it is proposed in this invention that the pressure reduction valve have a servo valve spool which is adjusted by the external parameter.

Abstract: A locking connection for releasably attaching a handling socket to the duct tube of a fuel assembly for a nuclear reactor. The connection comprises a load pad housing mechanically attached to the duct tube and a handling socket threadably secured within the housing. A retaining ring is interposed between the housing and the handling socket and is formed with a projection and depression engageable within a cavity and groove of the housing and handling socket, respectively, to form a detachable interlocked connection assembly.

Abstract: The servomotor is constructed in one embodiment with a partition which forms a constriction through which air is throttled during an emergency closing of the valve. The constriction is formed with a flow resistance equivalent to a free cross-sectional area of not more than 0.02D.sup.2 ; D being the inside diameter of the cylinder. In addition, the chamber defined between the piston and the partition is not more than 10% of the combined volume of this chamber and a pressurized chamber below the partition.In another embodiment, the pressurized chamber may be formed by a pressure tank which is connected via a line which forms a constriction to the chamber below the piston. In still another embodiment, a spherical pressure tank may be secured about a cup-shaped cylinder to form the pressurized chamber while radial grooves in a flange of the cylinder form a constriction with a cover secured to the cylinder and spherical tank.

Abstract: This invention teaches a nuclear fission reactor having a core vessel and at least one tandem heat exchanger vessel coupled therewith across upper and lower passages to define a closed flow loop. Nuclear fuel such as a uranium alloy in its liquid phase fills these vessels and flow passages. Solid control elements in the reactor core vessel are adapted to be adjusted relative to one another to control fission reaction of the liquid fuel therein. Moderator elements in the other vessel and flow passages preclude fission reaction therein. An inert gas such as helium is bubbled upwardly through the heat exchanger vessel operable to move the liquid fuel upwardly therein and unidirectionally around the closed loop and downwardly through the core vessel. This helium gas is further directed to heat conversion means outside of the reactor vessels to utilize the heat from the fission reaction to generate useful output. The nuclear fuel operates in the 1200.degree.-1800.degree. C. range, and even higher to 2500.degree.

Abstract: A control system for a hydraulic circuit having at least first and second hydraulic pumps of the variable displacement type, a first hydraulic actuator arranged for hydraulic connection with the first pump through first valve to be driven thereby, and a second hydraulic actuator arranged for selective hydraulic connection with said first and second pumps through second and third valve respectively to be driven thereby.

Abstract: The invention relates to a pool-type fission reactor power plant design having a reactor vessel containing a primary coolant (such as liquid sodium), and a steam expansion device powered by a pressurized water/steam coolant system. Heat pipe means are disposed between the primary and water coolants to complete the heat transfer therebetween. The heat pipes are vertically oriented, penetrating the reactor deck and being directly submerged in the primary coolant. A U-tube or line passes through each heat pipe, extended over most of the length of the heat pipe and having its walls spaced from but closely proximate to and generally facing the surrounding walls of the heat pipe. The water/steam coolant loop includes each U-tube and the steam expansion device. A heat transfer medium (such as mercury) fills each of the heat pipes.

Abstract: A hydrostatic steering system having a hand operated metering pump and steering control valve regulating and distributing fluid flow from a servo pump to a piston servomotor of the differential pressure surface type. A compensation valve disposed in the pressure line leading to one of the opposed chambers of the piston servomotor, is actuated by a differential pressure surface dimensioned to establish a constant ratio of pressures prevailing in the opposed pressure chambers in the neutral steering position while the metering pump is ineffective to produce any differential pressure. During active steering, the compensation valve is bypassed through a check valve.

Abstract: In a hydrostatic auxiliary power steering apparatus, a short-circuit passage of a control valve establishes a restricted flow path from a pump pressure line to a reservoir return line in the neutral position of the control valve wherein all other flow paths are blocked. A fixed flow restrictor in the pump pressure line conducts a continuous flow from one of two pumps connected to the pressure line for regulation of the fluid power steering circuit by the pressure drop across the flow restrictor. If one of the pumps is of the variable volume type, the pressure downstream of the flow restrictor is utilized to regulate pump flow adjustment. If fluid under operating pressure is supplied to both the fluid power steering circuit and another fluid operating circuit, a flow dividing valve controlled by the pressure differential across the flow restrictor distributes pressurized fluid between the two fluid circuits.

Abstract: The operation of a nuclear fueled, electric power generating unit is monitored by utilizing decision tree analysis of selected system parameters to generate a representation of the real time system status. Current system status is presented to the operator either in the form of conclusory indications, such as verbal statements, representative of system status, or in the form of a visual display of the entire decision tree including indications of the path through the tree representative of current conditions. In either case, indications of off-normal conditions are accompanied by directions as to appropriate action to be taken, either by the operator or the automatic control system, to steer the system toward more acceptable conditions. In addition, the status indications are prioritized to indicate the seriousness of the off-normal conditions and to direct the sequence of corrective action to be taken when multiple off-normal conditions exist.

Abstract: The invention relates to a steering control unit for a bidirectional servomotor which is connectable to steerable wheels. A steering wheel controlled quantity setting unit of a known type has ports connectable to a pump and a return tank and two control ports through which metered quantities of fluid flow to opposite sides of the servomotor and to other parts of the apparatus for actuating the servomotor. A directional control valve for selectivity directing pressurized fluid from a power circuit to opposite sides of the servomotor is controlled by a control circuit containing the setting unit. A utility valve having pressure regulating and control and power valve capabilities is provided. In cases wherein the quantity setting apparatus is remotely located from the regulating valve the length of the signal channels add to the reaction time.

Abstract: An engine piston is formed with a top crown surface and a top ring groove. An upper annular land surface is defined between the top ring groove and the edge of the top crown surface. The upper annular land surface and the side walls of the top ring groove are defined by a part of the piston which is formed of a matrix metal reinforced with inorganic fibers. The proportion of the inorganic fibers by volume in the reinforced part of the piston may optionally be approximately between 2% and 10%.