Abstract: An apparatus for moving an object in an isolated environment may be employed as a high pressure and temperature facility for testing steam generator tubes. A tube to be tested extends through an opening in a plate that is mounted in a test vessel. The vessel is partially filled with water having selected contaminants, and heated water under high pressure is circulated through the tube to raise the temperature and pressure within the vessel. A lever arm having an inner end and an outer end extends through an opening in the test vessel. A vibration-coupler connects the inner end of the arm to the tube under test, and a fulcrum-former operationally connects an intermediate portion of the arm to the test vessel. The outer end of the lever arm is connected to a plug element which is shaken, so that the arm pivots about a fixed point at the fulcrum-former and the vibration-coupler moves the tube under test with respect to the plate.

Abstract: An emergency feedwater system for the steam generators of a pressurized water nuclear reactor has two separately located subsystems, each subsystem supplying water to at least one steam generator when activated, where each subsystem contains an emergency feedwater supply tank, and a pair of emergency feedwater lines leading from the tank which communicate with the inlet line of a steam generator. An electrical operated motor driven pump is located in one of said pair of emergency feedwater lines and a steam turbine driven pump in the other of said pair, with a cavitating venturi provided in an emergency feedwater line between the pump and inlet line of the steam generator. The system is adaptable for use with two, three, and four loop pressurized water reactor systems.

Abstract: A multi-star fiber optic network achieves improved access periods by grouping terminal devices into subnetworks that are connected to a bus, with token passing or collision detection being localized to individual subnetworks and with communication between subnetworks being conducted over the bus via non-interfering optical channels. The optical channels may be obtained by using light sources having different wavelengths or by modulating light at different channel frequencies. Each subnetwork includes an N-to-1 star which receives optical signals from terminal devices in the subnetwork and 1-to-N star which distributes optical signals to terminal devices in the subnetwork. Each subnetwork also includes a transmit repeater connected between the N-to-1 star and the bus to transmit messages which are addressed to other subnetworks on a unique channel, and a receive repeater connected between the bus and the 1-to-N star to receive messages on the channels assigned to other subnetworks.

Abstract: A method for forming a sealed coupling between two bodies each body presenting an abutment surface. The respective bodies are arranged so that their respective abutment surfaces are axially adjacent one another, defining a space therebetween in which a deformable gasket is disposed. An axial external force is applied to the bodies for compressing the abutment surfaces together against the gasket to form a seal between the bodies. The bodies are immobilized relative to one another while the external force is being applied to the bodies so that sufficient compression will be maintained by the abutment surfaces to preserve the integrity of the seal when the external axial force is withdrawn. The external axial force is then withdrawn, leaving the two bodies coupled together via the seal.

Abstract: A method for remotely measuring the level of a bulk material in a vessel, wherein the bulk material comprises loose particles, with adjoining particles defining interstices therebetween. Liquid is added to the vessel at a constant flow rate through a liquid inlet of the vessel, wherein the liquid progressively fills the interstices of the bulk material from the bottom of the vessel to the surface level of the bulk material. The liquid level indications of a level measuring device are monitored as a function of time. The level at which the rate of change of liquid level in the vessel decreases is determined. Such level represents the surface level of bulk material in the vessel.

Abstract: An analog output network provides multiple communication paths for control of an actuator in response to an input signal. The analog output network includes at least two controllers, each of which is connected to an analog output circuit and a controller selector which is connected to each of the controllers and the analog output circuits. The controller selector ensures that at least one of the analog output circuits is enabled at all times and identifies one of the controllers as an on-line controller. The analog output circuit connected to the on-line controller generates an actuation signal which passes through the actuator and the other analog output circuit. An alternate current path comprising a diode string with a voltage drop larger than the voltage drop of the actuation signal in the other analog output circuit is provided so that if an analog output circuit is removed or defective, the actuation signal from the on-line analog output circuit is still provided with a current path.

Abstract: The range of objects from a television camera is obtained by projecting a series of patterns of uniquely coded stripes of light onto the objects at an oblique angle to the optical axis of the camera and capturing in the camera the coded light signals reflected by the objects. Through proper selection and scaling of a coordinate system and related coding of the light stripes, the range of the object is determined for each pixel by simply subtracting one coordinate of the pixel from the binary coded light signal reflected into the pixel.

Abstract: A system for effecting transport over a surface among a plurality of terminals, including at least one transport vehicle movable over the surface, light barriers dividing the surface into a plurality of contiguous elemental zones and sensing the passage of a vehicle across a boundary between two contiguous zones, light signal generators for emitting light signals identifying each zone occupied by a vehicle and identifying the location of each terminal, logic circuitry connected between the barriers and said light signal generators for controlling the light signals identifying each zone in response to passage of a vehicle across a boundary, a photoelectric receiver carried by the vehicle for sensing light signals produced by the light signal generators and producing electrical signals representative of the light signals, and a vehicle movement control circuit carried by the vehicle and connected to receive the electrical signals from the photoelectric receiver for controlling the movement of the vehicle in dep

Abstract: A refueling machine within a nuclear reactor facility includes an inner mast or gripper tube (12) to the bottom of which is secured a gripper assembly (16). An actuator tube (20) controls the gripper mechanisms of the gripper assembly (16), and in order to insure proper and accurate alignment of the gripper mechanisms with the fuel assembly nozzles, a television camera (26) is mounted within the actuator tube (20). A television monitor (34) is operatively connected to the television camera (26), the monitor (34) being disposed upon the refueling machine personnel trolley. The television camera (26) is removably mounted within the actuator tube (20) by a bayonet-type system which includes camera housing lugs (78) which are adapted to pass through slots (76), subsequent to which the camera housing (28) and the lugs (78) are rotated 90.degree. whereby the lugs (78) are seated within recesses (80).

Abstract: A fuel transfer system for transferring fuel assemblies through a transfer tube between fuel exchange locations respectively in a fuel storage and handling building and a containment structure of a nuclear reactor includes a segmented track comprising first, second and third track segments and a segmented drive screw comprising first, second and third drive screw segments respectively associated with the fuel storage and handling building, the transfer tube, and the containment structure. Gaps between the successive, corresponding track segments and drive screw segments permit operation of valves for closing the ends of the transfer tube during normal operation of the reactor, which valves are then opened during fuel exchange operations. The adjacent but normally displaced ends of the first and second and of the second and third drive screw segments include respective, mating engagement means.

Abstract: A refueling machine (100) is provided with a latching/unlatching rod (116) which is provided with a hexagonally configured head portion for mated engagement with a hexagonally configured socket (34) defined within a latching/unlatching screw (22) of a fuel assembly (10) whereby the fuel assembly (10) may be securely mechanically connected to the lower core support plate of the reactor internals. The latching/unlatching rod (116) is fixedly connected to a housing (118) which is co-axially disposed within a torque tube (140), the latter of which is fixedly secured to the lower end of a spur gear (130). The spur gear (130) is rotatably engaged with a drive spur gear (148) through means of an idler gear (128), whereby torque is transmitted to the torque tube (140).

Abstract: In the upper internals storage pit of a containment building housing a pressurized water nuclear reactor, there is installed a three-coordinate positioning apparatus which has a frame-like, horizontally oriented base track enclosing an area designed to be occupied by any of the control rod clusters when lowered from the upper internals supported in the storage pit; a mechanism for supporting and vertically displacing the base track in the storage pit; a traversing track supported on the base track for back-and-forth displacement in a first horizontal direction; a mechanism for moving the traversing track in the first horizontal direction; and a carriage supported on the traversing track for back-and-forth displacements in a second horizontal direction perpendicular to the first horizontal direction. The carriage is adapted to receive thereon inspection equipment.

Abstract: A procedure for vacuum degassing of a reactor coolant system which basically utilizes existing equipment to degas and refill the coolant system. The level of radiogas and non-radiogas concentration is reduced to low residual levels in less than two hours to expedite shutdown operations. The procedure enhances residual heat removal by using the steam generators as reflux condensers. During draindown of the reactor coolant to the midplane of the reactor vessel outlet nozzles, a two-phase pump is used and a vacuum is established in the vapor space created in the reactor pressure vessel, and the steam generators.

Abstract: A digital rod position indicator having discrete coils spaced along the travel path of an elongated magnetically permeable member stores in digital form compensation signals for automatically adjusting the location relative to the coils at which the digital output signal representative of the position of the end of the elongate member transitions from one code to the next. The appropriate compensation signal is addressed using the digital output signal and a correction factor which takes into account the direction of movement including reversals.

Abstract: A self-supporting pipe rupture and whip restraint system (10) for a process fluid pipe (12) of a nuclear reactor steam generator pressure vessel (14) includes a guard pipe (26) concentrically disposed about the process pipe (12) so as to entirely encase the process pipe (12) from the pressure vessel nozzle 18 to a terminal end fitting component (36) disposed exteriorly of the reactor facility building wall (32), the guard pipe (26) being integrally fixed to the process pipe (12) through means of the nozzle (18) and the component (36). Under postulated rupture conditions of the process pipe (12), pipe whipping of the process pipe (12) is restrained by the guard pipe (26), and the process fluid effluent from the process pipe (12) is contained within the guard pipe (26). Leak detection apparatus (50) is operatively associated with the annular space (30) defined between the process pipe (12) and the guard pipe (26) so as to detect ruptures or fractures within either the process pipe (12) or the guard pipe (26).

Abstract: A method and apparatus for producing a color strip display of eddy current test data from a signal produced by an eddy current detector and which varies in amplitude and in phase relative to a reference signal as the detector is displaced relative to a test body. In order to produce the display, a signal representative of the relative displacement of the detector, a signal representative of the amplitude of the detector signal, and a signal representative of the relative phase of the detector signal are produced and the representative signals are supplied to a color display device for producing a strip display which extends along a path determined by the signal representative of the relative displacement of the detector, has an amplitude perpendicular to the path which is a function of the signal representative of the amplitude of the detector signal, and has a color the hue of which is a function of the signal representative of the relative phase of the detector signal.

Abstract: A redundant d.c. power supply arrangement for supplying power to a load circuit, wherein the power supply arrangement is subjected to voltage transients of high frequency and magnitude which emanate from the load circuit. The arrangement includes first and second power supply branches connected in electrical parallel with the load circuit. Each power supply branch includes a d.c. voltage supply and a Zener diode connected in electrical series with the voltage supply. The Zener diodes are selected and arranged for causing at least one of the voltage supplies to deliver power to the load circuit. Each Zener diode has a reverse breakdown voltage for clamping a voltage transient emanating from the load circuit to that Zener breakdown voltage and provides a low impedance path for a resulting current surge associated with the voltage transient.

Abstract: A refueling machine (10, 100) within a nuclear reactor facility includes an outer stationary mast (12, 112) upon which are mounted a plurality of light sources (28, 128), inclined mirrors (36, 136), and television cameras (24, 124) for scanning a fuel assembly (32) for the existence of any defects or damage as the fuel assembly (32) is being withdrawn from the reactor core into the stationary mast (12, 112). In a first embodiment, the light sources (28), mirrors (36), and cameras (24) are mounted upon a sleeve (14) clamped about the lower end of the stationary mast (12), while in a second embodiment, the light sources (128), mirrors (136), and cameras (124) are mounted upon a basket-type framework (178) which is suspendingly supported upon the stationary mast (112) by support cables (158). A fixture (176) can support the framework (178) in an off-the-mast mode so as to permit remote-controlled maintenance or repair of the light sources ( 128), mirrors (136), or cameras (124).

Abstract: Numerous signal conditioning circuits on a plurality of printed circuit boards are calibrated remotely by a signal processing unit which sends coded signals to each board, either sequentially or in parallel, to connect either on-board or off-board test signals to one of the conditioning circuits in place of its field generated input. The processing unit utilizes the actual and expected responses of each conditioning circuit to low and high test signals to generate a gain and an offset which are applied to the conditioned field signal to provide a calibrated signal. The time constant for each conditioning circuit is also measured periodically, or upon a selected temperature change, for use in generating a minimum waiting period for obtaining valid data following transfers between the field generated signals and the test signals.

Abstract: Axially spaced measurements of the neutron flux in a pressurized water reactor are used to generate point-by-point signals representative of the core average xenon-135 axial distribution and the rate of change thereof. These signals may be used directly to generate visual displays representative of the xenon-135 distribution and/or can be used to generate a skewness signal representative of divergence of the xenon-135 distribution from the equilibrium, full power axial xenon-135 distribution and a rate of change of the skewness signal. A two dimensional comparison of the skewness and rate of change of skewness signals can be used in a xenon control mode of a wide band constant axial offset control system to automatically position the control rods to dampen the xenon transients.