General Electric Company

Edward W Saxon

Frank Ortega

Robert S Tsukida

Thomas W White

Bettadapur N Sridhar

Balasubramanian S Kowdley

Thomas A Lewis

Thomas R Eckmann

Benedict Kazirskis

Christopher J Miller

Paul Debenedetto

Andrew S Wong

Edward J Pulpan

An uncoupling tool has a two-module design: one module being a driver assembly for developing the uncoupling movement and the other module being a probe assembly for verifying the uncoupled condition. The probe assembly attaches to the threaded end of the piston tube with its probe extending inside the piston tube. The driver assembly attaches to the CRD ring flange. The probe assembly detects the ring magnet in the drive piston using analog position sensors which operate on the principle of the Hall effect and solid state circuitry. A top sensor provides a signal indicating that the control rod is in its 'full out' position; a bottom sensor provides a signal indicating that the control rod is uncoupled; and an intermediate sensor provides a signal indicating that the control rod is in a transition position between the 'full out' and uncoupled positions. The probe incorporates spacers which focus the magnetic flux onto the sensors. To uncouple the control rod, the probe assembly is lifted using a separate driver assembly.

Multistage control rod drive uncoupling tool

A method and a gage for testing uncoupling tools to ensure proper operation prior to use. The uncoupling tool gage simulates the actual conditions under which the uncoupling tool is expected to perform. The gage has a cylindrical guide for slidably receiving a magnet housing. The guide is supported such that it is concentric with respect to the probe of an uncoupling tool to be checked. The magnet housing is placed inside the cylindrical guide and then moved toward the bottom thereof. When the magnet moves into proximity with a switch in the uncoupling tool probe, an indicator lamp in the uncoupling tool illuminates. If the face of the magnet housing is within a range band on the outside of the guide when the indicator is illuminated, then the uncoupling tool is operating properly.

Control rod drive uncoupling tool gage

A tool for checking the length of a control rod drive measured from the top of the control rod drive flange to the end of the uncoupling rod. The tool is a GO--NO--GO gauge with tight tolerance. The top of the tool supports a gage which has an arm that pivots about an axis parallel to the tool axis. The arm has a stepped notch with a predetermined height equal to the length tolerance range (e.g., 0.0625 inch). The length is considered acceptable when the gage is rotated and the first edge of the stepped notch on the arm just clears the end of the uncoupling rod but the second edge stops the gage from pivoting any further. The length is not acceptable if the first edge of the stepped notch on the arm abuts the uncoupling rod, preventing the gage from pivoting any further, or if the gage misses the uncoupling rod entirely.

Control rod drive length measurement tool

A gauge for ensuring that the uncoupling rod of a control rod drive is properly inserted in the center hole of the spud and not in one of the outer lobes, i.e., spud flow holes, which communicate with the center hole. The uncoupling rod is inserted in the spud. Then the gauge is placed on top of the spud with a centering ring protruding into the spud. The uncoupling rod is correctly installed if it is free to slide inside the gauge and the spud. The gauge is also provided with a ring to protect the spud during transfer of the control rod drive.

Uncoupling rod centering gauge

An effluent container has two halves which fit together to form a cylinder, open at the top, for catching residual contaminated water falling from the control rod drive (CRD) housing under the influence of gravity when the seal between the CRD housing and the CRD is broken. The container has an aperture which fits around the extension rod that supports the CRD when the mounting bolts are removed. The container halves are held together by elastic cords stretched between hooks on the side-walls. The effluent container has L-shaped slots which hook onto the bracing bolts of the sway brace system to support the container in position for catching falling water. Spilled water drains out of the container to a sump.

Effluent container

An improved tool for removing a highly contaminated outer filter from a control rod drive during a maintenance operation. The tool slides onto the control rod drive and surrounds the outer filter with a shield. The shield has a window for removing the screws used to mount the outer filter on the control rod drive. The tool has a support for the spud on the inside thereof. A U-shaped handle is slidably inserted into guideways so that it interlocks with circumferential slots in the shield. The arms of the inserted U-handle latch underneath the ring flange of the outer filter, whereby the outer filter is captured by the tool. The filter-mounting screws are then removed by unscrewing through the aligned window in the shield. Thereafter, the outer filter is removed from the CRD when the outer filter removal tool is lifted.

Growing community of inventors

San Jose, CA, United States of America

Edward W Saxon