Abstract: An analysis device for detecting fission products by measurement of a radioactivity includes a first line for carrying a liquid sample, a first detector connected to the first line and designed for measuring the radioactivity of fission products contained in the liquid sample, a second line for carrying a gas sample and a second detector connected to the second line and designed for measuring the radioactivity of fission products contained in the gas sample. The analysis device includes a separation device for separating gas from the first line carrying the liquid sample, which line has an outlet opening into the second line for gas separated from the liquid sample. The outlet opening fluidly connected to the second lines in such a manner that the gas separated from the liquid sample is suppliable as a gas sample to the second detector for measuring the radioactivity of fission products contained therein.

Abstract: A device and method for performing ultra-sound scanning of a substantially cylindrical object. The device comprises a cuff adapted to fit around a circumference of the object, an ultrasound probe mounted about the inner circumference of the cuff and positioned to scan the circumference of the object, and one or more data connections providing control information for the ultrasound probe and receiving scanning data from the ultrasound probe. The probe includes one or more sensors to determine its orientation or location, and this data is used to control the operation of the device and to process data from the array.

Abstract: Disclosed are methods and systems to nondestructively detect cracks at or near a countersink of a fastener, such as a rivet, in a thin walled structure using Lamb waves. Generation and detection of Lamb waves at symmetric locations relative to the fastener provides signals used to calculate a symmetry parameter. The symmetry parameter represents a comparison of the relative amplitudes of the detected Lamb wave signals and provides a simple indication of whether a crack exists.

Abstract: Methods for performing non-invasive thrombolysis with ultrasound using, in some embodiments, one or more ultrasound transducers to focus or place a high intensity ultrasound beam onto a blood clot (thrombus) or other vascular inclusion or occlusion (e.g., clot in the dialysis graft, deep vein thrombosis, superficial vein thrombosis, arterial embolus, bypass graft thrombosis or embolization, pulmonary embolus) which would be ablated (eroded, mechanically fractionated, liquefied, or dissolved) by ultrasound energy. The process can employ one or more mechanisms, such as of cavitational, sonochemical, mechanical fractionation, or thermal processes depending on the acoustic parameters selected. This general process, including the examples of application set forth herein, is henceforth referred to as “Thrombolysis.

Abstract: A portable device for inspecting a weld of metal tubes, comprises: at least one clamp formed from two jaws, each jaw including a circularly arcuate void defining, once the clamp has been closed, a substantially circular slot suitable for receiving a tube the weld of which is to be inspected; at least two multielement ultrasound probes that are mounted to be movable relative to the inspecting device and to be able to rotate relative to an axis passing through the center of the two lateral portions of the substantially circular slot of a clamp; a means configured to drive the ultrasound probes to rotate to pass around the entire circumference of the weld to be inspected; and an angular sensor configured to deliver a signal representative of the angular position of at least one sensor relative to an initial position.

Abstract: An apparatus for measuring external corrosion in pipes is disclosed.

Abstract: Provided is an inspection robot that is self-propelled on piping, measures moisture contained in a lagging material using a mounted inspection device, for example, a neutron moisture meter, and detects risk of corrosion. The inspection robot includes a main frame 1 including a recessed part 17 fit onto an outer circumferential surface of piping P, a main frame drive mechanism (first drive mechanism) D1 that causes the main frame to advance/retract in an axis direction of the piping, a revolving member 32 supported in an advanceable/retractable manner along an arc-shaped locus in the recessed part of the main frame, a revolving member drive mechanism (second drive mechanism) D2 that moves the revolving member, and an inspection device mounted on the revolving member.

Abstract: An ultrasonic inspection device includes: a vibration generating section that irradiates laser beam onto a first member to generate ultrasonic vibration; a detecting section that detects the ultrasonic vibration propagated from the first to a second members via a welded portion; and an analyzing section that analyzes the propagated ultrasonic vibration detected by the detecting section. The analyzing section obtains at least one of frequency and wavelength of the ultrasonic vibration detected by the detecting section upon when a displacement in the second member in a thickness direction becomes maximum. The analyzing section obtains a cross sectional dimension of the welded portion from a correlated relationship of the cross sectional dimension of the welded portion obtained in advance at a position on a surface of the second member on the first member side and the at least one of the frequency and wavelength of the ultrasonic vibration.

Abstract: The invention relates to a method for localizing a defect in an electrochemical store (165). The method includes a step of controlling the temperature of a subarea (145, 150, 155, 160, 170) of the electrochemical store (165) to increase an internal pressure of the subarea (145, 150, 155, 160, 170), a step of detecting a measured value which represents an escape of a component from the subarea (145, 150, 155, 160, 170) occurring in response to the increased internal pressure of the subarea (145, 150, 155, 160, 170), and a step of localizing the defect in the subarea (145, 150, 155, 160, 170) when the measured value is in a predetermined relation to a comparison value.

Abstract: Immersion ultrasonic NDE is performed within cavities of inanimate objects, having downwardly directed openings, such as for in situ inspection of steam inlet sleeves and steam inlet necks within steam turbine housings. A shaft assembly has one or more single angle or phased array ultrasonic probes that are affixed on an upstream or distal end. An inflatable bladder is affixed to the shaft on a proximal end of the shaft assembly downstream the ultrasonic probe(s). The shaft is inserted into the cavity opening, and the bladder is inflated to form a fluid tight seal against the cavity. Immersion fluid is introduced upstream the bladder in the volume occupied by the probes. Immersion ultrasonic inspection of the object is then performed.

Abstract: A system and method for monitoring the properties of a fluid, such as water, in a steam pipe without mechanically penetrating the wall of the pipe. The system uses a piezoelectric transducer to launch an ultrasonic probe signal into the pipe. Reflected ultrasonic signals are captured in a transducer, which can be the same transducer that launched the probe signal. The reflected signals are subjected to data processing, which can include filtering, amplification, analog-to-digital conversion and autocorrelation analysis. A result is extracted which is indicative of a property of the fluid, such as a height of the condensed fluid, a cavitation of the condensed fluid, and a surface perturbation of the condensed fluid. The result can be recorded, displayed, and/or transmitted to another location. One embodiment of the system has been constructed and tested based on a general purpose programmable computer using instructions recorded in machine-readable non-volatile memory.

Abstract: An ultrasonic probe carrier includes a base, a first side arm having a first end thereof attached to the base and a second end thereof extending outwardly from the base on one side of a tube, and a second side arm having a first end thereof attached to the base and a second end thereof extending outwardly from the base on an opposite side of the tube, at least a portion of the first and second side arms being biased towards each other to removably secure the carrier around at least a portion of a circumference of the tube. An ultrasonic probe is attached to the base, and the carrier and ultrasonic probe are rotatable around the tube to scan at least one of: the circumference of the tube and a weld disposed around the circumference of the tube.

Abstract: An acoustic detector assembly for detecting a leak of a pressurized mixture of liquids and gases in a pipeline or pressurized vessel that includes an ultrasonic acoustic transducer generating an output in response to receiving an acoustical signal associated with the leaking mixture of liquids and gases, a detector connected with the acoustic transducer.

Abstract: A method of predicting stresses on a BWR steam dryer that includes creating an analytical acoustic model of a BWR steam system; generating pressure estimations by inputting empirical data into the analytical acoustic model of the BWR steam system; creating an analytical structural model of the BWR steam dryer; and predicting stresses on the BWR steam dryer using the analytical structural model and the pressure estimations.

Abstract: An ultrasonic inspection method and ultrasonic inspection apparatus is capable of inspecting a weld line and of detecting a circumferential crack and an axial crack that are present in the weld line. An ultrasonic probe is placed on the surface of a structure and transmits an ultrasonic wave. The ultrasonic wave is transmitted at an angle in an X?-Z plane. The direction of a normal to the surface is defined as an X axis. The direction in which the weld line extends is defined as a Y axis. The direction perpendicular to the X axis and the Y axis is defined as a Z axis. An axis obtained by rotating the X axis around the Z axis is defined as an X? axis. A control mechanism performs signal processing of signals reflected from the defect or defects to detect the defect or defects and to measure the length of the defect or defects.

Abstract: An object of the present invention is to provide an inspection apparatus for inspecting weld zones in a reactor pressure vessel, the inspection apparatus comprising: an ultrasonic probe 6 for emitting an ultrasonic wave; a probe holding unit 60 for holding the ultrasonic probe 6 such that a ultrasonic wave transmitting surface of the ultrasonic probe 6 is kept in direct contact with or at a constant distance from the outer surface of the reactor pressure vessel 1; a pressing unit 50 for pressing the probe holding unit 60 parallel to a central axis of a control rod drive housing 8 against the reactor pressure vessel; and a rotator 40 for rotating the probe holding unit 60 and the pressing unit 50 about the central axis of the control rod drive housing 8.

Abstract: A method of inspecting, performing maintenance on, or repairing a nuclear reactor may include operatively connecting a fixing device, a first track, an arm including one or more second tracks, and an effector to form an apparatus; inserting the apparatus into the reactor; fixing the apparatus within the reactor; and operating the apparatus. At least one of the one or more second tracks may include at least three track sections. The arm may have a contracted length. The arm may have an expanded length. The expanded length may be greater than two times the contracted length. The first track may include one or more motors configured to move the arm relative to the first track. A method of operating a reactor may include shutting down; inspecting, performing maintenance on, or repairing the reactor; and starting up the reactor.

Abstract: A tool assembly provides for brushing circumferential welds in a restrictive access area between a cylindrical inner member and a cylindrical outer member such as the shroud and vessel in a nuclear reactor. The tool assembly includes a circumferential plate sized larger than an outside diameter of the inner member and smaller than an inside diameter of the outer member. At least one renew brush is coupled with the circumferential plate, and a motor is coupled with the renew brush that rotates the renew brush. A driving assembly mounted between the inner member and the outer member engages the circumferential plate and circumferentially drives the circumferential plate in the restrictive access area.

Abstract: The ultrasonic probe of the ultrasonic inspection apparatus, which is pushed onto the outer surface of the reactor pressure vessel, transmits and receives an ultrasonic wave to and from a penetration having a welded portion while changing an incident angle of the ultrasonic wave. Based on a result of reception of an echo obtained by the reflection of the ultrasonic wave on the inner surface of the penetration, an inclination angle of the penetration relative to a wall surface of the reactor pressure vessel is measured. A circumferential direction position of the penetration, which corresponds to the inclination angle, is calculated based on the relationship of an inclination angle and a circumferential direction position, which have been calculated in advance. Then, the circumferential direction position can be obtained as information on the inspection position.

Abstract: A miniature air gap inspection crawler. The miniature air gap inspection crawler may include a base, a linear drive mechanism and a circumferential drive mechanism such that either the linear drive mechanism or the circumferential drive mechanism may be employed, and an inspection module connected to the base.

Abstract: The present invention relates to a nondestructive method or inspecting defects of the cladding of a nuclear fuel rod, which is featured by a wave emitter obliquely discharging an inspection wave to an inspected tube and a receiver arranged at a side of the inspected tube with respect to the wave emitter. If liquid is accumulated inside the tube, the incident inspection wave will be refracted so that the receiver can receive the refracted inspection wave at a specific location. The method can determine whether liquid is accumulated inside the tube and further is able to detect the level of the liquid.

Abstract: The diameter of a segment of a peripheral rod in a fuel assembly is measured between two successive spacer grids. A measuring tool is positioned at a level situated between the two successive spacer grids, the tool comprising two measuring fingers that are free to move relative to each other in a first horizontal direction and that are urged towards each other by a resilient return arrangement, and that extend in a second horizontal direction perpendicular to the first horizontal direction. The measuring fingers are moved in the second horizontal direction towards a rod so as to put two contact pieces of the measuring fingers into contact with two zones of the rod segment. The measuring fingers are moved in the vertical axial direction of the rod along its segment situated between the two spacer grids and an electromagnetic sensor is used to measure the distance between the measuring fingers in the first horizontal direction while the measuring fingers are being moved axially.

Abstract: The contents of a container 1 are non-intrusively monitored by probing the container with an ultrasonic signal, and measuring changes in the ultrasound signature of the received signal after the signal has passed through the contents of the container.

Abstract: An inspection apparatus for inspecting jet pump beams of nuclear reactors is provided. The inspection apparatus includes a base straddlingly mountable on a jet pump beam. The base includes a beam bolt opening sized to receive a jet pump beam bolt. A first transducer holder is coupled to a first side portion of the base, and a second transducer holder coupled to a second side portion of the base. The first side portion is opposed to the second side portion. Each holder includes an adjustment cylinder configured to contact the jet pump beam when activated.

Abstract: A preferred embodiment may generally be construed as providing a method for storing fissile material, such as spent nuclear fuel (SNF), and includes the steps of: providing a storage container configured to receive the fissile material therein; and applying a coating to a surface of the storage container. Preferably, the coating is formed, at least in part, of a neutron-absorbing material and is adapted to reduce neutron multiplication and/or provide a shielding of the fissile material received within the storage container. Systems also are provided.

Abstract: An inspection apparatus for inspecting welds in a nuclear reactor jet pump includes a probe subassembly rotatably and linearly movably coupled to a frame structure configured to attach to a top flange of the reactor pressure vessel. The probe subassembly includes a plurality of probe arms pivotably coupled to a housing, with each probe arm including a sensor. The probe arms are pivotably movable between a first position where the probe arms are parallel to a longitudinal axis of the probe subassembly, and a second position where the probe arms are at an angle to the longitudinal axis of the probe subassembly. An insertion subassembly couples to the jet pump suction inlet. The insertion subassembly is sized to receive the probe subassembly and guide the probe subassembly into the jet pump through the jet pump suction inlet.

Abstract: An end effector for supporting an ultrasonic testing probe on a robot arm having a robot mounting bracket for use in a nuclear reactor pressure vessel. The end effector has a wrist assembly with a rotatable wrist axle. The wrist assembly is coupled to the robot mounting bracket and a probe assembly is coupled to the wrist shaft. The ultrasonic testing probe is floatably disposed within the probe assembly.

Abstract: Scan methods of inspecting piping and welds of a pipe elbow in a reactor pressure vessel of a boiling water reactor are disclosed. The scan apparatus includes a motor connected to a scan head having two ultrasonic transducer probes each including an ultrasonic transducer, a transducer arm connected to each transducer probe, a scan platform having an arcuate cutout, and a connector connecting each transducer arm to the scan platform. The scan head allows the transducer probes to remain substantially in contact with the pipe elbow while the scan head traverses the pipe elbow. The scan apparatus further includes a pivot arm connecting the scan platform to a pivot pin. The method includes the steps of positioning the scan head and the transducer probe such that the ultrasonic transducer is substantially in contact with the pipe elbow surface. Then moving the scan head axially along the pipe elbow in a first direction while maintaining the ultrasonic transducer in substantial contact with the pipe elbow surface.

Abstract: A method and an apparatus for ultrasonically inspecting the welds which attach the differential pressure and liquid poison nozzles to the bottom head of the reactor pressure vessel in a boiling water reactor. The scanning apparatus is seated on the upper taper of the nozzle outer tube and incorporates a stationary frame having a cutaway section which allows installation from the side. The apparatus has vertical and circumferential positioning mechanisms which are operated remotely to scan an ultrasonic transducer package over the circumferential welds and heat-affected zones thereof. The rotating frame has a transducer carriage mounted thereon which is vertically displaceable relative to the rotating frame. The vertical and angular motion motors can be controlled together to provide the desired path for the ultrasonic transducer around the stub tube. The tool also includes a vessel contour follower which follows the contour of the inclined surfaces of the reactor pressure vessel bottom head.

Abstract: Automated inspection assemblies for scanning pipes of a nuclear reactor are described. In one embodiment, the assembly includes a mounting subassembly and a scanning subassembly. The mounting subassembly includes a clamp configured to be mounted to selected pipes in a nuclear reactor pressure vessel, and the scanning subassembly is movably coupled to the mounting subassembly. The scanning assembly includes a scanning head configured to scan at least a portion of the circumference of the pipe to be inspected, and the scanning head includes a substantially "U" shaped transducer support assembly sized to receive the pipe. Transducer elements are coupled to the transducer support assembly legs, and the transducer support assembly is configured to rotate about the pipe to inspect the pipe.

Abstract: The apparatus for inspecting the rods of a cluster insertable in the core of a nuclear reactor comprises a body provided with sliding guide means for rods in m different orientations of the cluster, m being a submultiple of the number n of rods in the cluster, and a measurement jig carrying n/m heads (16) for eddy current examination and n/m probes (18) for ultrasound scanning placed on different guide paths. Each ultrasound probe (18) is constituted by an annular support surrounding a rod path and carrying a ring of individual transducers. The transducers are connected to a circuit for sequentially exciting the transducers in successive groups, causing the tube to be scanned circumferentially, and for electronic focusing towards the surface of a tube travelling on the path.

Abstract: A system and method of the present invention measures the relative stress in the cladding of a nuclear fuel rod caused by the internal gas pressure of the rod. This is done by determining the attenuation ratio of two specific frequencies from a broadband low frequency acoustic energy spectrum. Relative pressure differentials are measurable and therefore any loss of fuel rod gas pressure is a direct indication of fuel rod cladding failure.

Abstract: A probe inspects steam generator tubing for defects. The probe includes a transducer which generates a localized ultrasonic Lamb wave. The ultrasonic wave is transferred to the tubing by a coupling medium, such as water, that physically couples the transducer and the tubing. Defects in the tubing reflect the ultrasonic wave to the probe which detects the reflections. The results are then used to determine the length and depth of such defects as cracks, pitting, and thinning. The localized ultrasonic wave performs an inspection sensitive enough to detect ligaments between crack segments. This allows highly accurate predictions of tubing integrity and rupture strength.

Abstract: A reactor pressure vessel top guide structure inspection and transport system comprising a remotely operable and positionable underwater vehicle for traversing the top guide structure of a reactor pressure vessel and for positioning an inspection system for detecting defects in the top guide structure.

Abstract: An ultrasonic flaw detecting apparatus for efficiently detecting a flaw existing in a deep portion of a multi-layer structure includes a first sensor arranged so as to transmit an ultrasonic wave into a different property layer surrounded by a medium having a different acoustic impedance in the multi-layer structure, a function generator for generating a pulse-shaped sine wave, a power amplifier for amplifying and supplying the pulse-shaped sine wave to the first sensor, a second sensor arranged so as to receive a boundary echo from the different property layer, a first amplifier for amplifying the boundary echo received by the second sensor, an intensity detector for judging the intensity of an amplified signal of the boundary echo, a third sensor arranged so as to receive an echo from a flaw inside a layer in a deep portion of the different property layer, a second amplifier for amplifying the flaw echo received by the third sensor, a recorder for recording the amplified flaw echo signal, and a control unit

Abstract: A process and an apparatus for the ultrasonic testing of a component accessible only through a gap, includes driving a carrier accommodating an ultrasonic testing head into an annular gap and bringing the ultrasonic testing head into a position of alignment with the component, for the purposes of repeated testing of components disposed in the poorly accessible gap. Subsequently, the ultrasonic testing head is driven out from the carrier approximately at right angles to the driving-in movement, and is brought into contact with the component. After completing the testing process, the ultrasonic testing head is driven once more into the carrier and brought into a position of alignment with the next component.

Abstract: A component maintenance system having a network linked to a data acquisition system, a data analysis system, a historical file of component design and inspection information, and a diagnostic system having the capability to perform structural analysis of discontinuities identified by the data acquisition system. The network nodes may be located apart from each other; for example in the maintenance of a nuclear power plant steam generator, the data acquisition system may be located in a high radiation area while the data analysis system is safely located away from the radiation areas. Furthermore, the diagnostic system and the file of component design and inspection history information may be centrally located and shared to support component evaluations being conducted in numerous geographic locations. Network communication facilitates the rapid evaluation of discontinuities, thereby permitting the inspection plan to be modified as the inspection results are obtained.

Abstract: A sensor system for mapping absolute acoustic noise intensity in a three-dimensional acoustic noise field. Localized noise sources within a vessel are extracted using a distant array of transducers mounted on the vessel wall. The absolute intensity can be measured even when totally masked by background noise at the transducer locations. The system includes an integrated transducer installation. Each transducer is an accelerometer which is mounted on the vessel wall using a rigid attachment rod which serves as an ultrasonic waveguide. The output of each transducer is split into low- and high-frequency components, the low-frequency component being a function of the vibrational displacement of the localized portion of the vessel wall and the high-frequency component being a function of the vibrational/ultrasonic waves propagating through the localized portion of the vessel wall.

Abstract: A testing arrangement (14) and a method for materials testing at lead-throughs in a cap of a pressurized-water reactor, comprising a flexible sword (85) which at one end is equipped with a probe. Since the lead-throughs consists of a first tube passing the cap and welded to it, and a second tube inserted in the first tube, the weld joint has to be inspected from below via a gap between the tubes. In order to do this by means of a manipulator, a pinching arrangement (32) is arranged, which by pressing the inner tube towards one side widens the gap at the opposite side so that the sword can be inserted.The pinching arrangement and the sword can then be displaced so that the sword and the widened gap moves around the inner tube, in order that the whole weld and its surrounding area can be inspected.

Abstract: A method and an apparatus for inspecting a core shroud by remote operation. The apparatus is a robotic scanning device which can be installed in the narrow space between the core shroud and the jet pumps and which can scan azimuthally and vertically around the circumference of the core shroud. The scanning device provides gross positioning to the area of interest and precise motion control in a limited scanning range. The scanning uses a thin wide arm to support a bank of transducers at its bottom end, and is rigidly mounted to a precision two-axis positioner at its top end. The arm is of narrow thickness to pass through the 0.5-inch access opening and to allow radial flexibility to absorb surface contour variation over the inspection area. The transducer mounting includes a water jet thruster to provide a radially inwardly directed reaction force to maintain the transducers in contact against the shroud. The arm is fabricated with a row of longitudinal holes extending throughout its length.

Abstract: The tubular cladding (1) comprises an internal surface of substantially prismatic shape, having successive faces. An ultrasonic examination head (3) makes it possible to emit ultrasound waves in the form of pulses from the outside of the cladding (1), so that the ultrasound waves pass through the wall of the cladding (1) and scan the wall over its entire periphery. The frequency of the ultrasound pulses is adjusted as a function of the circumferential scanning speed of the cladding (1). An ultrasound signal reflected by the internal surface of the cladding (1) is recorded and the reflected signal is analyzed in order to examine the number and the amplitude of the faces and the variation in thickness of the tubular cladding (1) over one revolution.

Abstract: A method and an apparatus for in situ ultrasonic inspection of the core spray T-box to thermal sleeve attachment weld and the core spray T-box to cover plate attachment weld in BWRs. The apparatus incorporates a stationary clamping mechanism and sliding and rotational mechanisms which are operated remotely to scan the transducer over the T-box welds and heat-affected zones thereof.

Abstract: Corrosion damage to the tubes of power plant boiler waterwalls is detected by a portable hand-held ultrasonic scanner probe equipped with plurality of dual element transducers having concave cylindrically curved surfaces for simultaneously examining arcuate areas of walls of several tubes as the probe is moved along the waterwall. Tube wall thickness and probe location data are processed by a computer for detection, display and recording of places where significant tube damage has occurred.

Abstract: An accelerometer is mounted onto the releasable fuel gripper structure of a refueling machine to form a mechanical interconnection between an accelerometer and a nuclear fuel assembly during removal from a core of a nuclear reactor. An electrical signal is received and processed through an analyzer and recorded corresponding to mechanical vibrations occurring due to the passage of a fluid medium through a porous sidewall defect in a fuel rod of the fuel assembly which is induced by a hydrostatic pressure change on the fuel assembly during upward movement from the reactor core.

Abstract: A system for mapping absolute acoustic noise intensity in a three-dimensional acoustic noise field, and using three-dimensional absolute noise intensities to infer operational or performance characteristics of components or structures within the monitored field. Localized noise sources are extracted using a distant array of transducers, and the absolute intensity can be measured even when totally masked by background noise at the transducer locations. The system includes an integrated sensor installation; a neural network detection system algorithm; a zoom system to precisely examine a small region in the steam generator vessel; a fuzzy logic system detection algorithm; and an expert detection system. The signal processing subsystem operates at three different levels of detection. At the top level of detection a trained neural network system monitors the vessel length for any indication of a leak. The proposed approach uses discriminators which do not require any beamforming of the sensor signals.

Abstract: A system for inspection and mending in a reactor vessel of a nuclear reactor comprises a track mechanism, support mechanisms for supporting the track mechanism, an inspection apparatus traveling on the track mechanism, at least one mending apparatus traveling on the track mechanism, a setting mechanism for lowering all the above-described mechanisms and apparatus in the reactor vessel, each of which is composed so as to pass through a hole of an upper grid of a reactor, and an installing mechanism for positioning the support mechanisms fixed with two of the upper grid, a core support plate and internal structures below the core support plate and the track mechanism at the inside of the reactor vessel by remote control and for attaching the inspection apparatus and the mending apparatus to the same track mechanism by remote control.

Abstract: A system for mapping absolute acoustic noise intensity in a three-dimensional acoustic noise field, and using three-dimensional absolute noise intensities to infer operational or performance characteristics of components or structures within the monitored field. Localized noise sources are extracted using a distant array of transducers, and the absolute intensity can be measured even when totally masked by background noise at the transducer locations. The system includes an integrated sensor installation; a neural network detection system algorithm; a zoom system to precisely examine a small region in the steam generator vessel; a fuzzy logic system detection algorithm; and an expert detection system. The signal processing subsystem operates at three different levels of detection. At the top level of detection a trained neural network system monitors the vessel length for any indication of a leak. The proposed approach uses discriminators which do not require any beamforming of the sensor signals.

Abstract: A device for easily installing and removing strain gauge instrumentation and associated wiring on the inside of in-core monitor housings. A vibration sensor is attached to an inside diameter of a cylindrical housing. A signal cable is coupled to the vibration sensor and extends into an exterior of the reactor pressure vessel. A protective assembly minimizes the damage inflicted on the signal cables during handling. The signal cables are helically wound in an annular space between a pair of concentric thin-walled tubes and then passed through cable penetration bores formed in the body of a flange insert. The flange insert supports the concentric tube assembly and is sandwiched between the housing flange and the in-core monitor instrument flange of a conventional in-core monitor assembly.

Abstract: A method for ultrasonically inspecting a closely packed regular array of mutually parallel, uniformly sized and spaced rigid rods surrounded by a thin-walled metallic channel and immersed in a compressible medium. The method utilizes the properties of coherently scattered ultrasonic waves to identify rods which are defective, out of position or missing. A plane, monochromatic ultrasonic wave is transmitted toward the array of rods on one side thereof. Then an interference pattern produced on an opposing side of the array is detected. This interference pattern is the result of multiple scattering and diffraction of the plane ultrasonic wave during propagation through the array of rods. When the wavelength is comparable with the rod diameter and the rods are not too close together, scattering results in spatial relationships that produce an unusually large amount of wave penetration through the array in certain directions relative to the incident propagation vector.

Abstract: A compact ultrasonic inspection device of high resolution and operating speed is presented for examining the defects in a welded section between the end plug and the fuel pipe. The welded fuel rod is inserted into an inspection section of a rotating member filled with water, and is held immovably. The rotating member, having a plurality of ultrasonic probes disposed around the periphery, is rotated around the axis of the fuel rod to examine the welded section.