ML20043B120

Forwards, Diesel Generator Voltage Response Improvement Rept. Combined Effect of Resetting Exciter Current Transformers to Achieve flat-compounding & Installing Electronic Load Sequence Timers Produced Acceptable Voltage

ML20043B120
Person / Time
Site:	Sequoyah
Issue date:	05/18/1990
From:	Wallace E TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20043B121	List: ML20043B120 ML20043B606
References
RTR-REGGD-01.009, RTR-REGGD-1.009 NUDOCS 9005240213
Download: ML20043B120 (3)

Text

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TENNESSEE VALLEY AUTHORITY.

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CH ATTANOOG A, TENNESSEE 37401 SN 157B Lookout Place MAY 181990 U.S. Nuclear Regulatory Commission j ATTN: Document Control Desk Washington, D.C. 20555 1

Gentlemen: l In the Matter of' ) Docket Nos. 50-327 Tennessee Valley Authority ) 50-328 SEQUOYAH-NUCLEAR PLANT-(SQN) - IMPROVEMENT PLAN.FOR SQN DIESEL GENERATORS TRANSIENT-VOLTAGE RESPONSE q u

Reference:

TVA letter to NRC dated July 8, 1988, "Sequoyah Nuclear Plant l

.(SQN) - Improvement Plan for SQN Diesel Generators (DGs)  !

Transient-Voltage Response" - j

.t The purpose of this letter is to-provide.NRC with.the; evaluation and test ')

results of the postmodification tests performed for the-modifications. l implemented to provide acceptable improvement =in the SQN diesel generators ..

transient-voltage response. TVA committed by-the referenced. letter to provide  ;

NRC with the enclosed information.

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Based on the results of,the enclosed report, the combined effect of resetting l

.the exciter current transformers'to achieve flat-compounding; installing  !

! electronic load sequence-timers, and installing a voltage-overshoot-reduction I p device has produced acceptable voltage performance. meeting the numerical  !

l- guidelines of Regulatory Guide 1.9 for the SQN-Unit I diesel generators during .<

a design accident load sequence. Based on the similar postmodification' test  !

results for the Unit 2 diesel-generators, it is expected that=they'will also j meet the Regulatory Guide l'.9 voltage guidelines when the load. sequence tests y are performed.

There are no commitments contained in this submittal. Please-direct questions- f concerning this issue to Bruce S. Schofield at (615) 843-6172. l Very truly yours, TENNESSEE VALLEY AUTHORITY l

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E. G. Hallace, Manager Nuclear Licensing and Regulatory Affairs Enclosure cc: See page 2  ;

9005240213 900518 PDR b

P ADOCK 0300032'7 -

PDC

• An Equal opportunity Employer- o3o ,

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U.S. Nuclear Regulatory Commission MAY 181990 ,

cc: Ms. S. C.-Black, Assistant Director-(Enclosure) I for Projects. .. 1 TVA Projects Division ,

U.S. Nuclear Regulatory Commission- i One White Flint, North 11555 Rockville Pike *!

.Rockville, Maryland .20852 NRC Resident Inspector (Enclosure)

Sequoyah Nuclear Plant 2600 Igou Ferry Road <

Soddy Daisy, Tennessee '37379- i Mr. B. A. Wilson, Assistant Director (Enclosure)

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for Inspection Programs TVA Projects Division _

U.S. Nuclear Regulatory Commission- d Region II . -

101 Marietta-Street, NH, Suite ?900 Atlanta, Georgia 30323 ,

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. ENCLOSURE.

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.SEQUOYAH NUCLEAR PLANT DIESEL GENERATOR VOLTAGE RESPONSE IMPROVEMENT REPORT >

-(B37 900511 800)

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