Westinghouse Electric Company LLC

Westinghouse Electric Corporation

William K Cullen

Qui V Le

Craig Bowser

Warren R Junker

Robert F Keating

Lee W Burtner

Charles H Roth, Jr

David A Chizmar

Francis X Gradich

Thomas A Pitterle

Robert J Maurer

Warren E Lester

Lawrence Galata

The systems and methods of the invention pertain to analyzing steam generator tube data for the detection of wear. Further, the invention is capable of performing a comparison of current tube signal data to baseline or historic tube signal data, e.g., from previous and/or the first, in-service inspection of the steam generator. The systems and methods are automated and can generate results to show potential tube-to-tube contact wear areas as well as the progression of tube-to-tube gap reduction within a steam generator tube bundle. In certain embodiments, the invention is capable of comparing current and historical eddy current data to determine the difference that may be related to degradation or other interested phenomena, and of processing and trending historical comparison results to establish normal variance and detect abnormal variances.

Systems and methods for steam generator tube analysis for detection of tube degradation

A method predicts an amount of wear that is expected to occur on the tubes of a steam generator as a result of vibration against another structure within the steam generator. The method includes determining a volumetric amount of material that has been worn from a location on a tube over a duration of time and employing that volume as a function of time to determine the volume of material of the tube wall that is predicted to be worn from the tube or another tube at a future time. The volumetric-based analysis enables more accurately prediction of the wear depth at a future time. This enables the plugging of only those tubes that are determined from a volumetric analysis to be in risk of breach at the future time, thus slowing the rate at which tubes of a steam generator will be plugged.

Method of predicting wear on tubes of steam generator

Method of restricting transverse displacement of a nuclear heat exchanger tube support plate during a transient event, the support plate having a plurality of holes therethrough for passage of respective ones of a plurality of heat transfer tubes. The method includes radially expanding the tube adjacent the first side of the support plate to define a first expanded region thereat, the tube being expanded to a diameter greater than the diameter of the hole formed through the support plate. The method further includes radially expanding the tube adjacent the second side of the support plate to define a second expanded region thereat, the tube being expanded to a diameter greater than the diameter of the hole formed through the support plate. The first expanded region and the second expanded region coact to restrict transverse displacement of the support plate because the support plate is firmly captured between the first expanded region and the second expanded region.

Method of restricting transverse displacement of a nuclear heat

An apparatus and a method for remotely inspecting the interior walls of a cavity having a circular cross section that varies in diameter, such as the interior of a hollow tube plug. The apparatus has an eddy current probe head having a distal and proximal end, wherein the distal end engages the cavity walls, an elongated support assembly connected to the proximal end of the probe that is insertable within the cavity, a radial extender mechanism for radially extending and withdrawing the distal end of the probe with respect to the longitudinal axis of the support assembly, and a probe driving and delivery system for inserting the support assembly into the cavity and helically moving the probe head to inspect the cavity walls for discontinuities. In the method of the invention, the radial extender mechanism radially retracts the probe head within the support assembly when it is inserted through the cavity prior to the inspection operation in order to avoid mechanical interference, and then radially extends the probe head into engagement with the cavity walls. The probe driving and delivery system then helically moves the probe head across the cavity walls to scan the walls for discontinuities that indicate cracks.

System and method for inspecting metallic plugs in heat exchanger tubes

An improved robotic arm for effecting a tube plugging operation is disclosed herein. The improvement generally comprises the provision of a compliance coupling between the plugging tool and the guidance mechanism of the robotic arm that is compliant in three dimensions, thereby allowing the plugging tool to smoothly insert tube plugs into the mouths of heat exchanger tubes despite inaccuracies in alignment caused by sag and other factors. The improvement further comprises a length adjustment assembly for allowing the length of the base arm of the robotic arm to be easily and conveniently changed so that the robotic arm can service more than one particular type of nuclear steam generator, as well as an emergency release mechanism for remotely detaching the tool from the arm in the event of a jam. Finally, a rotary-type tube plug magazine is provided which includes a spring loaded drum having a plurality of spring clips mounted around its periphery for detachably retaining a large inventory of tube plugs and unloading these plugs without scratching. A stop mechanism with rollers prevents the tube plugs retained by the spring clips from rotating past an unloading position where the plugging tool can engage and smoothly remove the plug. Once a plug is removed at the unloading station, the torsional spring rotates the drum to advance another tube plug to the unloading position, where it may likewise be unloaded into the plugging tool.

Robotic arm for delivering a tube plugging tool

Growing community of inventors

Pittsburgh, PA, United States of America

William K Cullen