Abstract: Methods and apparatus are disclosed for taking advantage of a heat exchange relation between a liquid coolant and a protected liquid, whereby vaporization of the liquid coolant withdraws heat from the body of the protected liquid or an exterior heat source in order to prevent undue temperature rise within the body of the protected liquid.

Abstract: A method for determining the concentration of a plurality of combustible gases in a gas stream comprises providing an electrochemical cell apparatus that includes an electrochemical cell in which a cavity is formed having a diffusion limiting port forming the entrance to the cavity. The cell has a process side in flow communication with a portion of the gas stream flowing into the cavity through the port, and a reference side in flow communication with a reference gas. The process side and the reference side of the electrochemical cell are separated by an electrolyte. The potential difference across the cell is adjusted to create a steady state electrical current flow.

Abstract: A HP/LP seal arrangement is provided for a guide tube and thimble extending outwardly from the core of a nuclear reactor to a seal table where the guide tube is welded to the seal table to provide a high pressure seal relative thereto. A tubular seal fitting is disposed in alignment with the guide tube with the thimble extending therethrough on the low pressure side of the seal table.A first high pressure seal couples one end of the fitting to an end of the guide tube to prevent leakage from within the guide tube. Inwardly facing threading is disposed adjacent the other and outer end of the seal fitting. A nut is disposed about the thimble and it is provided with outwardly facing threading in mating engagement with the fitting threading.The fitting has a seal seat spaced longitudinally inwardly from the threading and facing the fitting outer end and extending annularly about the inner surface of the fitting.

Abstract: An immersion base ultrasonic inspection system for interrogating the bore and near bore material of turbine and generator rotors by passing ultrasonic search units through the rotor bore. This system utilizes variable focus array inspection transducers in a shear mode inspection of the near bore material. The system includes a positioning assembly for a transducer which includes carriage means for supporting the transducer and a first positioning means for tilting one end of the carriage means in a radial axial plane whereby the transducer may be positioned at an angle to a longitudinal axis of the system. A second positioning means is provided for circumferentially rotating the transducer to a known and repeatable angular position. Position resolver means are coupled to the first and second positioning means.

Abstract: The present invention includes a bore mapping system that includes one or more high resolution ultrasonic mapping transducers that are used to measure the diameter of a bore. The travel time for a normally incident pulse to reach the bore surface and return for each transducer is used with a reference reflection time measured in a calibration bore to determine the measured diameter from a mechanically measured reference diameter using a known velocity of the ultrasonic pulse in an immersion fluid. The diameter measured by each of the transducers is averaged to obtain an average measured diameter which is produced for plural axial rotor positions. The present invention also includes a surface time measurement system that uses at least one ranging transducer measuring the ranging time required for a ranging beam to reach and return from the bore surface.

Abstract: A closure system of a spent fuel storage cask includes a lid assembly having a shield lid which is installed under water and which cooperates in the drainage of water from the cask. A primary cover having a spring energized metalic C-ring captured therein to provide a primary gas seal is then installed over the shield lid. Closable gas passages extending through the primary cover permit the primary gas seal to be tested by injecting pressurized gas on one side of the primary gas seal and testing for leakage on the other. A seal cover is installed over the primary cover and welded at its periphery to provide the secondary gas seal. The seal cover has a closable gas passage which allows pressurized gas to be injected between the primary cover and the sealed cover so that leaks at the secondary gas seal can be detected. The closure system may also include a gas pressure monitoring system which communicates with the interior of the cask and which can be recalibrated during long-term storage of spent fuel.

Abstract: A device in a nuclear reactor for connecting a plurality of energy conveying cables to a nuclear reactor head structure comprising a pair of matching multiple cooperative connector plates for disengageably connecting an energy source with the reactor head structure; at least one of said connector plates being a movable connector plate; each of the multiple connector plates containing a multiplicity of individual connectors, each individual connector being one of a matching pair of connectors that are engaged when the matching multiple connector plates are brought together, each connector of the matching pair being mounted in corresponding locations on the opposing matching multiple connector plates; and at least one displacing means, affixed to a support structure on one end and to said movable connector plate at the other end, for accurately guiding the movable connector plate along a precise, predetermined path, such that the connectors of each pair of matching connectors meet in correct alignment.

Abstract: A beta ray flux measuring device in an activated member in-core instrumentation system for pressurized water reactors. The device includes collector rings positioned about an axis in the reactor's pressure boundary. Activated members such as hydroballs are positioned within respective ones of the collector rings. A response characteristic such as the current from or charge on a collector ring indicates the beta ray flux from the corresponding hydroball and is therefore a measure of the relative nuclear power level in the region of the reactor core corresponding to the specific exposed hydroball within the collector ring.

Abstract: A circuit device for simulating a selected one of a plurality of process transducers, including: signal input and output terminals connectable to external conductors; a plurality of circuit components (90,92,94; 104,108) connectable between the signal input and output terminals; a coupling device (106) connected between two of the circuit components for conducting a signal between the two components; and selective connecting members including connector terminals connected to at least one of the circuit components (90,92,94; 104,108), and connector elements for establishing conductive connections between selected ones of the connector terminals for configuring the circuit device to apply to the signal output terminal a signal corresponding to the output signal of a selected transducer.

Abstract: A flow sensor includes a strap-on heater attached to a fluid conduit downstream of a drain valve and two differential temperature measuring thermocouples attached to the fluid conduit downstream of the heater. A monitoring system employing at least one of the flow sensors further includes a controller which receives the differential temperature signal produced by the two thermocouples, a signal indicative of a selected valve position, and a signal indicative of steam turbine operating condition, i.e., hot or cold. The controller includes a logic circuit for correlating the differential temperature value signal, the valve position signal and the steam turbine condition signal to a diagnosis of the drain valve condition.

Abstract: A cryogenically coolable inductive coil including: a multicomponent conductor comprising a plurality of components, each component including a cable of conductive material having a longitudinal axis about which the cable is twisted, the cable being wrapped helically and being compacted, after wrapping, to minimize voids in the cable and to give the component a polygonal profile, the components being disposed parallel, and adjacent, to one another with mutually facing sides of adjacent components being in contact with one another; and an electrical insulating and support structure at least partially surrounding the conductor for supporting stresses induced in the conductor due to magnetic fields created by the flow of current through the conductor, the conductor and the structure being wound to form the coil.

Abstract: The present invention is a cycle monitoring system and method that acquires, logs and analyzes analog and/or digital signals from component sensors in a process control plant such as a nuclear power plant. The system continuously monitors the sensors and records steady-state and transient phenomena. Compression of the data is performed to reduce storage load. The compression ratio for transient data is driven by a threshold indicating a measurement signficant to stress determination. Transient data is retained at a higher sampling rate, so that the parameters of transient such as the maximum value can be determined for stress analysis. The stress analysis determines pressure and thermal stresses which are used to calculate a usage factor which indicates the stress age and thus the remaining life of a component. The system provides estimates of fatigue accumulation associated with selected locations of critical power plant components.

Abstract: This invention relates to a method for measuring vibration in turbine blades and to an apparatus for mounting a sensing device for monitoring blade tip vibration in turbo-machinery. A guide tube is mounted through the cylinder covers of a turbine and extends to a position adjacent to the tip of the turbine blades. The guide tube is sealed at the cylinder covers and has a gate valve external of the turbine cylinder covers. A method for measuring vibration and turbine blades while the turbine is in full operation includes the steps of removing a dummy probe partially from the guide tube while the turbine is in operation. With the dummy probe still in a portion of the guide tube, the gate valve is closed.

Abstract: Instrumentation and monitoring systems utilize, as differential temperature sensors, heated, split-well thermowells of duplex design, mounted to the sidewall of a pressure vessel and communicating through a penetration in the sidewall with the fluid state within the vessel. Each probe has at least one parallel axial bore therein, a related, selected pair of probes receiving respective heater and temperature sensing elements in the associated bores and together functioning as a differential temperature sensor producing distinguishable, differential temperature outputs representative of the presence of steam versus water. The systems monitor the differential temperature outputs of plural such sensors to produce alarm indications and perform verification and error checking of the sensor output indications.

Abstract: A pressurized water reactor of an advanced design comprises, in vertically spaced relationship, a lower barrel assembly having lower and upper core plates, an inner barrel assembly and an axially removable calandria assembly having a lower calandria plate. A plurality of rod guides are cantilever-mounted in parallel axial relationship within the inner barrel assembly and, specifically, are rigidly mounted at the lower ends thereof to the upper core plate. Axially extending sleeves are affixed to the upper ends of the rod guides and telescopingly receive therein generally cylindrical supports which are affixed to and depend downwardly from the lower calandria plate and define alignment axes for the respectively associated rod guides.

Abstract: The present invention includes a keyboard encoder which encodes a key selected by an operator. The encoder is isolated from a bi-directional bus by an isolation circuit. When a key has been selected a key code is made available for reading by a separate CPU. The separate CPU enables transfer of the key code from the encoder to the bi-directional bus and then reads the key code. The separate CPU acknowledges receipt of the key code and provides feedback to keyboard operator by sending a bank and light selection code to the keyboard over the bi-directional interface bus, after the isolation circuit has been reactivated and after a function, to be performed by the separate CPU and specified by the key code, has been started. The isolation circuit prevents the key code and the bank and light selection code from becoming intermixed on the bi-directional bus. The bank select code is used to select a bank of light code decoders which activate a light corresponding to the light code.

Abstract: An immersion based ultrasonic inspection system is disclosed which is used to interrogate the bore and near bore material of turbine and generator rotors by passing ultrasonic search units through the rotor bore. This system utilizes variable focus array inspection transducers in a shear mode inspection of the near bore material. The flaw location method includes recording calibration transit times and transducer locations for calibration holes from which refraction angles, and material velocities are determined. When a flaw is detected the surface time for a bore surface reflection, the flaw reflection time and transducer position are used to determine the position of the flaw.

Abstract: Differences between both the code and documentation of a revised generation of software and a previous generation are compared by a digital computer with the intended revisions stored in a release file. When all discrepancies have been eliminated, and for the original generation of the software, actual impacts in the form of the locations in the program where one routine is called by another and where common statements and public variables are used, are compared with expected impacts stored in the release file. When all actual impacts have been identified, the revised software, or the original version in the case of newly created software, is stored in a library with the code and documentation paired, and with each revision of each unit identified for later retrieval and reconstruction of any software generation.

Abstract: A spider assembly for supporting a corresponding rod cluster in a pressurized water reactor vessel, through which the core outlet flow passes in a predetermined direction. Each spider assembly comprises a generally cylindrical, central hub disposed in parallel axial relationship to the predetermined direction of the core outlet flow and a plurality of vane assemblies. Each vane assembly comprises means for mounting at least one rod to the assembly and at least one vane element connecting the rod mounting means to the hub. Each vane element has generally parallel, major planar surfaces disposed parallel to the predetermined direction of flow and a square trailing edge configuration which mitigates the shedding forcing function on the spider resulting from the core outlet flow thereover, while maximizing material content and thereby the strength thereof.

Abstract: A heated, split thermowell comprises a cylindrical shank and integral, axially extending, part-cylindrical probes spaced by at least a first gap defined by a bilateral plane. The thermowell is mounted to the sidewall of a pressure vessel for communicating through a penetration in the sidewall with the fluid state in the pressure vessel. Each probe has at least one parallel axial bore therein, a related, selected pair of probes receiving respective heater and temperature sensing elements in the associated bores, and together functioning as a differential temperature sensor producing distinguishable, differential temperature outputs representative of the fluid condition of steam versus water. Duplex sensor embodiments permit toggling between different, selected such pairs of probes for on-line testing and verification of monitored conditions and operability of the elements and supporting circuits, with automatic substitution of complementary elements in the event of element failure.