ML19332D365

Submits Revised Response to IE Bulletin 80-20, Failures of Westinghouse Type W-2 Spring Return to Neutral Control Switches. Review Identified 444 Westinghouse W-2 Switches Originally Installed at Plant

ML19332D365
Person / Time
Site:	Sequoyah
Issue date:	11/28/1989
From:	Michael Ray TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
IEB-80-20, NUDOCS 8912010076
Download: ML19332D365 (2)

Text

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' TENNESSEE VALLEY AUTHORITY -

CHATTANOOGA, TENNESSEE 3740i  !

5N 1578 Lookout Place: 'I

, e NOV 281988-

U.S.. Nuclear Regulatory Commisston ATTN

Document Control' Desk Washington, D.C 4 20555 Jl b Gentlemen:

. In the Matter of ) Docket Nos. 50-327 Tennessee Valley Authority- ) 50-328-SEQUOYAH NUCLEAR PLANT (SQN)' IELBULLETIN 80-20,-FAILURES OF WESTINGHOUSE h TYPE W-2 SPRING RETURN TO NEUTRAL CONTROL SWITCHES

.This submittal provides a revised response to IE Bulletin 80-20 for SON Units 1 and 2.

s TVA has completed a. review and has identifled 444 Westinghouse Electric .

Corporation H-2 switches originally installed at SQN. The switches are listed  ;

and the evaluation results documented in Calculation SQN-El-008.

,Eight of the 444 W-2= switches have been replaced by Electro Switch Corporation's Electroswitch units, which do not exhibit the problem. For 106

..of the switches with Indicating lights, the circuits have been wired to  ;

monitor contact continuity in the spring-return-to-neutral position. The '

lights were wired in series with the switches and are energized when the .

switch spring. returns to the neutral position. The remaining 330 W-2 switches

. at SON require no-modification. These switches are acceptable without modification because one of the following four conditions applies: <

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-l. The switch is not used to perform any function necessary for. safe shutdown 7 of the plant.  ;

2. The controlled device will go to its safety position or there is an alternate actuation if the neutral-switch position contact failed to close '

) upon spring. return.

3. The. neutral position contacts are not used to' perform a function required for_ safe shutdown.

'4. LThe switch is required by procedure to be manually verified / actuated when (

It is necessary to perform its safety-related function.

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,, 8912010076 891128 ADOCK 05000327

{DR PDC

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,g An Equal opportunity Employer

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e.. NOV 281989 U(S.NuclearRegulatoryCommission No commitmenlis are contained in this' submittal. Please direct questions ,

concerning this-issue to Kathy S. Whitaker at (615) 843-7748.

Very-truly yours,

, TENNESSEE VALLEY AUTHORITY ,

N '

Managec)_ Nucle 1 ensing and Regulatory Affairs

-cc: .Ms.S.'C. Black,NssistantDirector ,

for Projects.

TVA Projects Division '

.U.S. Nuclear Regulatory Commission One White Flint,. North

'11555 Rockville Pike

< Rockville, Maryland 20852 7

Mr. B. A. Wilson, Assistant Director for.. Inspection Programs TVA-Projects' Division U.S. Nuclear Regulatory Commission

-Region II-101 Marietta Street, NW, Suite 2900 -

Atlanta, Georgia 30323 NRC Resident Inspector

.Sequoyah Nuclear Plant 2600 Igou Ferry Road Soddy Daisy,' Tennessee 37379

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