Abstract: An electrical metering system includes an electrical meter which is free of current sensors and an external current sensor for producing an output signal related to electrical current conducted by a transmission line to an electrical load associated with the electrical meter such that the power consumption of the electrical load can be computed by the electrical meter. The current sensor generally can include an unbalanced bridge circuit for producing a scaled output signal related, according to a predetermined ratio to the electrical current conducted by the transmission line. The electrical meter generally includes a register, responsive to the output signal produced by the external current sensor, to tabulate load data related to the power consumption of the associated electrical load.

Abstract: Power output switching circuit for use in high current and high frequency applications. The output circuit provides a series of geometrically symmetric, parallel spaced semiconductor converters arranged such that the voltage for each semiconductor output device is substantially equal and minimal for each device. In this way, each device exhibits substantially the same impedance, such that circuit performance is largely a function of intrinsic device characteristics, and substantially independent of cross coupling and other external influences.

Abstract: A method for modeling linear control systems that are asymptotically stable provided that any initial deviation is within a definite bound is described. The method includes the steps of generating a parametric model of the quasi steady state system, generating a time-invariant parametric mapping function, using the system model, to relate a system setpoint parameter at a system setpoint function to an input process parameter implicit in a system implicit parameter, and generating an interface protocol to adjust the time-invariant parametric mapping function to account for any time-dependent variations in the relative performance between the input process parameter and the implicit system parameter.

Abstract: A check valve for use in a GDCS of a nuclear reactor and having a motor driven disk including a rotatable armature for rotating the check valve disk over its entire range of motion is described. In one embodiment, the check valve includes a valve body having a coolant flow channel extending therethrough. The coolant flow channel includes an inlet end and an outlet end. A valve body seat is located on an inner surface of the valve body. The check valve further includes a disk assembly, sometimes referred to as the motor driven disc, having a counterweight and a disk shaped valve. The disk valve includes a disk base having a seat for seating with the valve body seat. The disk assembly further includes a first hinge pin member which extends at least partially through the disk assembly and is engaged to the disk. The disk valve is rotatable relative to the first hinge pin member. The check valve also includes a motor having a stator frame with a stator bore therein.

Abstract: A medical catheter for treating atherosclerotic plaque and other abnormalities includes optical fibers for applying laser energy to the plaque and an ultrasonic transducer system for sensing the location and configuration of the plaque. The optical fibers and electrical wiring for the transducers extend through a probe which is rotatable inside of the catheter tube to provide universal directional control of the fibers and transducers. A reflective system includes a curved reflector in the probe which can be axially adjusted to vary the directions of the ultrasonic signals. Alternative forms of the invention include different reflector schemes, an angled ultrasonic transducer having a conical signal output that varies with frequency, and various different systems for rotating the transducers and fibers.

Abstract: A capacitive sensor device for use at least up to 1300.degree. C. and 40 bar, including a coaxial cable comprising a conductive sleeve (10) and at least one inner conductor (21) which are separated by an insulator (19), said cable having an end portion (1) of enlarged diameter forming a probe in which the insulator is an anticorrosive refractory element (9, 29) locked by a first and a second anticorrosive refractory metal protection element (5, 4), welded to the sleeve and to said inner conductor, respectively, which second protection element forms an electrode (4) having a flat surface (4a) of an area larger than the cross-sectional area of the end portion of the inner conductor.

Abstract: A truss spacer and support device for installation between the chords of adjacent trusses includes an elongate, generally U-shaped channel member. There is a tongue on each end having at least one nail integrally formed thereon which is adapted to overlie the top of a chord with the integral nail embedded therein. Tabs extend from each side of the channel member at each end with at least one nail integrally formed thereon. The tabs are raked inwardly toward the opposite end sufficiently that the ends of the nails do not extend past the ends of the channel member sufficiently to interfere with positioning the device between the chord members of adjacent trusses. The tabs can be bent to overlie the sides of the chord, with their integral nails embedded therein. The devices are employed to accurately space and support trusses during construction of a structure, and to provide added support against in-service loads.

Abstract: Methods and apparatus for detecting the onset of stress corrosion cracking are described. In one aspect, the present invention is a passive detector for in-situ detection of the onset of stress corrosion cracking in a nuclear reactor. The detector includes a ceramic insulator mounting member. A first material sample and a second material sample are secured to the mounting member. In the one embodiment, a metal bolt extends through the first and second material samples and secures the samples to the mounting member. The first material sample is cold worked to induce residual tensile stress and the second material is not cold worked. A first electrical conductor is electrically connected to the first material sample and a second electrical conductor is electrically connected to the second material sample.

Abstract: Methods and apparatus for enabling repeatable positioning of inspection and other service tools on an inner diameter of a shroud wall between a top guide and core plate in a boiling water nuclear reactor are described. In one embodiment, the delivery system includes a positioning unit configured to attach to a shroud head flange, a strong back assembly, and a rail assembly connected to the strong back assembly. The positioning unit includes a horizontal member having a plurality of slots and circular shaped openings to mate with seismic pins on the shroud head flange, a radial member and a z-axis adjustment assembly. The radial member extends from the horizontal member to the z-axis adjustment assembly. The z-axis adjustment assembly includes a mast coupling and an elongate screw threadedly attached to the coupling so that as the screw rotates, the coupling moves relative to the radial member. The strong back assembly includes a mast and an extension unit.

Abstract: Repair assemblies and methods for a jet pump diffuser in a nuclear reactor are described. In one particular embodiment, the diffuser has a substantially conical shape, and the larger diameter end of the diffuser is engaged to a shroud support plate of the reactor. The diffuser further has at least a first portion and a second portion welded together at a weld joint. The assembly, in one embodiment, includes a first c-ring having a first frusto-conical portion and a second substantially planar portion, and a second c-ring having a first frusto-conical portion and a second substantially planar portion. The first and second c-rings are configured, in the one embodiment, so that when the first and second c-rings are operatively positioned, first and second openings in the first c-ring are substantially aligned with first and second openings in the second c-ring, respectively.

Abstract: In a programmable logic controller data is exchanged between a data communication section and a sequential control section. Within the sequential control section a communication task is activated for a given period during each PLC cycle. Subsequently, inter alia a user task is activated; this user task controls a machine or a process inter alia on the basis of the data exchanged. By making the ratio of the period in which the communication task is active to that in which the user task is active adjustable, very time-critical processes with a very short response time can be controlled as well as large amounts of data can be exchanged in few PLC cycles during less time-critical phases of operation of the machine or process to be controlled.

Abstract: An actuator for performing work in a nuclear reactor is described. In one embodiment, the actuator includes an x-axis linear slide assembly, a y-axis linear slide assembly, and a z-axis linear slide assembly. The x-axis linear slide assembly is mounted to a junction box, the y-axis linear slide assembly is mounted on a carriage of the x-axis assembly, and the z-axis linear slide assembly is mounted on a carriage of the y-axis assembly. The actuator also includes motor assemblies coupled to respective linear slide assemblies. Each motor assembly includes a motor and a resolver sealed in a leakproof can. Pulley-timing belt assemblies couple each motor to a respective lead screw. Specifically, a drive pulley is connected to a rotor shaft of each motor, and a lead screw pulley is secured to an end of each lead screw. Each pulley-timing belt assembly also includes an idler pulley, and a belt extends around the lead screw pulley, the idler pulley, and the drive pulley.

Abstract: Liquid cooled electric motors including stator frames having cast in place cooling conduits are described. In an exemplary embodiment, the conduit is arranged in a generally helical configuration and the stator frame is cast around the conduit so that the conduit is embedded within, and integral with, the frame. Spacer, or stabilizer, bars are engaged to the conduit and provide support for the conduit and facilitate maintaining the desired spacing between lengths of conduit and between the conduit and the frame wall. The stator frame with the cast in place cooling conduit has the advantages of a liquid cooled motor yet is believed to be lower cost than known liquid cooled motors. The frame also is believed to be less susceptible to corrosion and liquid leaks as compared to known liquid cooled motors.

Abstract: A refueling machine having relative positioning capability for refueling a nuclear reactor. The refueling machine includes a pair of articulated arms mounted on a refueling bridge. Each arm supports a respective telescoping mast. Each telescoping mast is designed to flex laterally in response to application of a lateral thrust on the end of the mast. A pendant mounted on the end of the mast carries an air-actuated grapple, television cameras, ultrasonic transducers and waterjet thrusters. The ultrasonic transducers are used to detect the gross position of the grapple relative to the bail of a nuclear fuel assembly in the fuel core. The television cameras acquire an image of the bail which is compared to a pre-stored image in computer memory. The pendant can be rotated until the television image and the pre-stored image match within a predetermined tolerance.

Abstract: A repositionable puzzle having a base, at least one removable piece having a first surface having a fastener adapted to releasably engage the base and a second surface having indicia. A panel is attached to the base. The panel has clue and answer indicia thereon. The at least one removable piece is moved on the base from a position adjacent to the answer indicia on the panel to a position adjacent to the corresponding clue indicia on the panel to complete the puzzle. A method of playing a puzzle game on a repositionable puzzle having a base, at least one removable piece having a first surface having a fastener adapted to releasably engage the base and a second surface having indicia, a panel attached to the base having clue and answer indicia thereon, the method includes the step moving the at least one removable piece on the base from a position adjacent to the answer indicia on the panel to a position adjacent to the clue indicia on the panel to complete the puzzle.

Abstract: A jig system for aligning wooden chords and metal web members in the manufacture of joists, the system includes an assembly surface having a longitudinally extending track therein, and a plurality of jigs positionable in the track. The jigs have upwardly projecting pins for engaging alignment holes in the webs for properly orienting and spacing the webs. The jigs may also have generally parallel alignment bars on either side of the pin for holding the portion of the metal web surrounding the alignment hole therebetween.

Abstract: The present invention, in one form, is a collapsible pitcher's practice cage including a frame and a fabric enclosure. The frame includes a first portion and a second portion. The frame second portion is pivotally coupled to the frame first portion so that the frame second portion is movable between a first position, where frame second portion is substantially perpendicular to frame first portion, and a second position, where frame second portion is substantially parallel to frame first portion. The fabric enclosure includes a rear wall and a bottom wall and is foldably coupled to the frame. Particularly, the rear wall is coupled to the frame first portion and the bottom wall is coupled to the frame second portion so that when the frame second portion is in the first position, the rear wall is substantially perpendicular to the bottom wall, and so that when the frame second portion is in the second position, the rear wall is substantially parallel to the bottom wall.

Abstract: Methods and apparatus for securing a tie rod to a shroud support structure are described. One embodiment of the apparatus is a toggle bolt assembly including a toggle bolt body having an upper threaded portion and a lower toggle engaging portion. A toggle is rotatably secured to the toggle bolt body at the lower toggle engaging portion. A crimp nut including a threaded nut portion and a crimp collar is threadedly secured to the upper threaded portion of the toggle bolt body. Such toggle bolt assembly also includes a sleeve sized to have at least a portion of the toggle bolt body and the toggle located therein. The sleeve has a toggle opening so that the toggle can rotate from a first position in which the toggle is substantially located within the sleeve to a second position in which surface engaging portions of the toggle extend beyond the sleeve. A lower portion of the sleeve has a toggle rotation surface to facilitate rotation of the toggle.

Abstract: A bottom head dome assembly which includes, in one embodiment, a bottom head dome and a liner configured to be positioned proximate the bottom head dome is described. The bottom head dome has a plurality of openings extending therethrough. The liner also has a plurality of openings extending therethrough, and each liner opening aligns with a respective bottom head dome opening. A seal is formed, such as by welding, between the liner and the bottom head dome to resist entry of water between the liner and the bottom head dome at the edge of the liner. In the one embodiment, a plurality of stub tubes are secured to the liner. Each stub tube has a bore extending therethrough, and each stub tube bore is coaxially aligned with a respective liner opening. A seat portion is formed by each liner opening for receiving a portion of the respective stub tube. The assembly also includes a plurality of support shims positioned between the bottom head dome and the liner for supporting the liner.