General Electric Company

Other

Thurman D Smith

Jack P Clark

David L Richardson

Balasubramanian S Kowdley

Richard W Perry

Alan Carl Foster

Peter M Patterson

Jack Toshio Matsumoto

James Hibbert Oates

James C Tung

David C Berg

A reference block for determining the characteristics of individual ultrasonic transducers contained within right circular cylinder type ultrasonic probes. Right circular cylinder type ultrasonic probes are designed for performing ultrasonic inspections of components that can only be examined from within a center line access hole. The reference block is made from the same material as that of the right circular cylinder type components which will be examined using the ultrasonic probe being characterized and is designed with curved contact surfaces that specifically duplicate the surfaces of those components. This reference block can be used to calibrate instruments prior to contact inspection using angle-beam search units. The reference block is also useful for checking the performance of both angle-beam and straight-beam search units and for evaluating instrument performance.

Reference block for determining operating characteristics of ultrasonic

A soft membrane booted transducer for performing ultrasonic inspections of parts and components that have rough sound beam entry surfaces. These rough surfaces may be in the form of as-welded unprepared overlays, cladded components, as-cast parts, or other unprepared surfaces that tend to prohibit, or prevent, sound entry from normal, smooth, hard-surfaced transducer contacting shoes made from Lucite or similar materials. The booted ultrasonic transducer has a soft membrane boot for coupling the transducer to an uneven or rough sound beam entry surface. The soft membrane is made of a flexible material capable of transmitting ultrasonic waves. When pressed into contact with the uneven or rough surface of the object being inspected, the membrane flexes to generally conform to the shape of the contacted surface. Flexing of the membrane eliminates or reduces air gaps between the transducer and the object surface, thereby increasing the ultrasonic coupling between the piezoelectric element and the object.

Booted ultrasonic transducer

An especially designed probe carries preferably five transducers for the examination of a right circular cylinder flooded with water having limited vertical clearance from the point of required non destructive inspection. The probe includes a generally disc shaped body having a minimal vertical dimension and a radius slightly less than the radius of the right circular cylinder to be inspected. Insertion of the probe interior of the right circular cylinder occurs. At the periphery of the disc, there are disposed five interrogating acoustical transducers. These transducers are spaced from preselected staggered circumferential locations with respect to the right circular cylinder for examination of the water flooded cylinder with refracted rays. The respective transducers are disposed with disclosed angularities and spatial orientation from their point of intended inspection to satisfy Snell's law with respect to the diameter of the right circular cylinder being examined to enable all points on any given radius of the right circular cylinder to be acoustically interrogated. A process of interrogation is disclosed which includes mounting the disc on a rotatable shaft, elevating the disc on the shaft to an elevation having the point of required interrogation intersecting the disc. Upon rotation of the disc, each of the interrogating transducers rotates sequentially to the point of required acoustical interrogation for the desired non destructive acoustical interrogation of the right circular cylinder.

Ultra sound probe for cylindrical body having reduced vertical clearance

An automated system for examining incore housing welds in a nuclear reactor from above is disclosed. The probe uses both ultrasonic and eddy current non-destructive inspection coils to examine the weld for indications, or flaws. It is inserted into the incore housing tube from above because of the high radiation exposure workers experienced using the prior method of inserting a probe into the incore housing from below. This is conveniently done when the incore flux monitors are removed during standard maintenance, and is performed from the refueling bridge.

Incore housing examination system

Method and apparatus for carrying out the in situ inspection of the shaft of a pump. A spacer coupling or link is manually removed from a limited access area intermediate the pump drive and top of the pump shaft. Inspection then is carried out through a previously formed inspection bore extending concentrically along the interior of the shaft. A probe supported by an extension assembly is lowered into the inspection bore until characterizable portions of the shaft such as a labyrinth seal region are identified. A discrete small region of interest which will initially evidence any fault condition then is surveyed with a raster scan movement of the inspection probe. Lower components of the region of interest are also identified by a next adjacent characterizable region such as a fillet welding for a journal assembly. Because of the limited longitudinal extent of the region of interest, the raster type movement of the probe becomes available. A calibration mock-up of the shaft is employed to provide ultrasonic signal readout information to apprise the operator of the presence of characterizable regions and the effectiveness of inspection transducer operation.

Method and apparatus for carrying out the in situ inspection of the

An apparatus and process for the remote inspection for stress corrosion cracking of welded shut boiling water reactor shroud access cover plates is disclosed. The apparatus consists of a streamline housing having a top side with lugs for the attachment of lowering lines on either end of the housing. Medially of the streamline housing and projecting downwardly from the bottom of the streamline housing, there is provided a central rotating pedestal with a rubber base. The rotating pedestal and rubber base enable the entire housing to rest on and rotate relative to the pedestal and rubber base. A first motor interior of the housing rotates the housing at a bevel gear rigidly mounted to the central pedestal. A second motor rotates a threaded shaft driving a ball screw with an attached mount for an ultrasound transducer. The mount and transducer responsive to rotation of the ball screw traverse along the elongate dimension of the housing over an opening through the bottom of the housing. A focused ultrasound transducer passes above the metal to be inspected. This ultrasound transducer focuses the sound through the water at an oblique angle to and from the metal of the hatch cover plate for an ultrasonic examination for stress corrosion cracking.

Apparatus for ultrasonic examination of BWR shroud access cover plate

In operation, the device is lowered with paired lines attached to both housing lugs but suspended under tension only from one line to one lug so that the streamline housing is vertically disposed. With the housing vertically disposed during lowering, obstacles can be avoided such as the guide rod for the steam separator and dryer as well as the feedwater and core spray spargers. When lowered to the vicinity of the ledge and cover plate to be inspected, the slack line is fished around any obstacle and thereafter placed under tension. The streamline housing is then lowered using both lines in a horizontal position so as to expose downwardly the pedestal and rubber foot. Lowering is completed with remote camera assistance. Sample sweeps with the ultrasound transducer of spaced apart sections of the cover plate weld are used for precise centering of the pedestal and rubber base with respect to the center of the cover plate. Repeatedly logging a longitudinal excursion of the ultrasound detector with indexed rotation of the housing permits scanning entirely around the weld of the cover plate. This enables remote ultrasound survey of the weld of the cover plate for stress corrosion cracking.

Ultrasonic examination of BWR shroud access cover plate retaining welds

An apparatus for the remote examination of peripheral shroud hold down bolts on steam separators used in boiling water reactors is disclosed. The testing apparatus is used while the steam separator is in a holding pool. The testing apparatus includes a depending pole having attached at the bottom thereof an aluminum shoe. The shoe has a flat, upwardly exposed bottom and opens to one side at gathering surfaces to receive the lower ends of the shroud bolts. The upwardly exposed bottom of the shoe defines an aperture through which an upwardly exposed piezoelectric device is exposed for direct contact with the bottom of the bolt. An overlying clamp member is provided to clamp the lug onto the bottom of the shoe for testing. The clamp member defines a receiving slot to receive the shaft of the bolt immediately overlying the rectangular lug. The clamp member slides over the shaft at the slot into contact with the top of the lug. The clamp member clamps the lug end of the bolt securely onto the upwardly exposed piezoelectric device on the upwardly exposed bottom of the shoe. A piezoelectric ultrasonic test is then run from the bottom and radioactive portion of the bolt to and towards the top of the bolt. Testing for longitudinal sound waves, refracted sound waves and shear sound waves for inter granular stress corrosion cracking can occur despite the radioactive and remote under water location of the bolts.

Apparatus for the ultrasonic examination of shroud hold down bolts

A system for on-site, non-destructive examination of the seam welds or other portions of the walls of a vessel, for example, a nuclear reactor pressure vessel, including an instrument carrying, remotely controlled vehicle with magnetic adherence means which may be selectively propelled to any position on the walls of the vessel and including an ultrasonic signal system utilizing a triangulation technique for remotely indicating the position of the vehicle on the vessel.

Vessel examination system

Apparatus for on-site, non-destructive examination of the connection of a pipe to a vessel including a vessel-to-nozzle and nozzle-to-pipe weld seams, including an instrument carrying, remotely controlled vehicle with magnetic adherence means for scanning such connection.

Growing community of inventors

San Jose, CA, United States of America

Thurman D Smith