General Electric Company

Robert S Tsukida

Frank Ortega

Edward W Saxon

Thomas W White

Balasubramanian S Kowdley

Douglas K Ethridge

Thomas A Lewis

Bettadapur N Sridhar

Harry I Russell

Christopher J Miller

Robert K Lovell

Thomas R Eckmann

Andrew S Wong

Edward J Pulpan

Herbert B Dela Rosa

Paul Debenedetto

Dale M Oliver

Vincent R Cantacessi

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 removal of the internal bushings from a piston coupling of a CRD. The tool incorporates a spring-loaded and hardened collet supported on one end of a ram. The collet has a pair of arms with shoulders or projections which latch inside the internal bushing ring to be removed. The tool is inserted into the piston coupling from either end, depending on which internal bushing is to be removed. The tool is inserted until the latching shoulders or projections snap behind the radially inwardly projecting internal bushing, with the contact surfaces of the shoulders or projections in contact with a radial end surface of the bushing. The bushing can then be dislodged, from the inside out, by impacting the other end of the ram with a hammer.

Internal bushing removal 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 improved tool for removing the highly contaminated inner filter from a control rod drive during a maintenance operation. The tool may also be used to install the inner filter by pushing the inner filter on and locking the spring clip onto flats of the center lug of the control rod drive stop piston. The tool has a collet with flexible fingers which are inserted inside the inner filter while flexed radially inward. After the collet is inserted, a retractable cam with a conical bearing surface is retracted to a position whereat it urges the collet fingers radially outward to clamp the collet onto the inner filter. The locked filter must be rotated before removal. With the inner filter coupled to the collet, the tool is then pulled out to remove the inner filter from the control rod drive.

Inner filter removal tool

A multi-port tool which tests for leaks in the seals of a control rod drive that has been removed from its housing. The fixture is attached to the flange of the control rod drive using quick-release clamps. Two ports of the fixture are respectively coupled to the insert and withdraw ports of the control rod drive. A source of demineralized water at a constant pressure is applied to an inlet port of the leak test fixture. The pressurized water is applied to the control rod drive while the index tube is restrained by a restraining rig. A number of valves are selectively opened or closed to provide a flow path for the pressurized water to either the insert port or the withdraw port. The leakage rate at each of a number of leakage points is determined when the pressurized water is applied at the insert port only and again when the pressurized water is applied at the withdraw port only.

Leak test fixture

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.

Outer filter removal tool

In a post-accident sample needle system, at the sample station, an improved seal for a PASS liquid sample needle is disclosed. In such systems, a bottle with a septum is impaled on paired needles. The first needle provides venting, and the second needle provides for the placement of potentially radioactive samples in the bottle through the septum. A needle of the hypodermic type having an angled point is provided with a flared end remote from the point. A rubber O-ring fits over the needle adjacent the flare having an inner circumferential diameter that permits passage along the length of the needle and trapping at the end of the needle adjacent the flare. The O-ring is captured at the flared end of the needle by a conventional compression nut. The nut, when tightened, compresses the O-ring to circumferentially expand beyond the edges of the flare to form a seal between the needle and O-ring and to form a secondary seal between the bore and O-ring. In the expansion of the O-ring, the needle is self-centered and braced for the dispensing of a sample.

Growing community of inventors

San Jose, CA, United States of America

Robert S Tsukida