IR 05000328/1988030

Forwards Safety Evaluation Supporting Compensatory Measures Re Core Shutdown Margins,Per LER 50-328/88-030.LER Applies to Unit 1 Core 4 & Unit 2 Core 3 Which Are Current Cores for Units

ML20154R144
Person / Time
Site:	Sequoyah
Issue date:	09/30/1988
From:	Black S NRC OFFICE OF SPECIAL PROJECTS
To:	White S TENNESSEE VALLEY AUTHORITY
Shared Package
ML20154R147	List: IR 05000328/1988030 ML20154R180
References
TAC-R00398, TAC-R00399, TAC-R398, TAC-R399, NUDOCS 8810040181
Download: ML20154R144 (3)

Text

. September 30, 1988

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Docket Nos. 50-327/328 Distribution

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' Docket File MSimms NRC PDR JRutberg Mr. S. Local POR FMiraolia Senior Vice President, Nuclear Power OSP Reading B. Grines Tennessee Valley Authority Projects Rdg. EJordan 6tf 38A Lockout Place JPartlow ACPS(10)

1101 Markct Street SRichardson GPA/PA Cattannoga, Tennessee 37402-2801 SDLiaw GPA/CA FMcCoy SCN Pdg. File

Dear Mr. White:

JDonohew SURJECT: CORE SHUTDOWN MAPGIN - SECUOYAH NUCLEAR PLANT, UNITS 1 AND 2 (TACSR00398,R00399)

By letter dated July 14, 19P8, the Tennessee Valley Authority (TVA) submitted a Licensee Event Report (LER 50-328/88-030) on the shutdown margin in the cores for Sequoyah Units 1 and 2. This LER apolies to Unit 1 core 4 and Unit 2 core 3 .shich are the current cores for the units. Unit 1 is preparing to begin cycle 4 operation and Unit 2 is in cycle 3 operation. The number assioned to the core for each unit is the cycle the unit is currently in or preparing to enter when the unit returns to power.

The staff conducted an inspection on this subject during July 11-14, 1988, reviev:ed the above LER and reviewed TVA's letter of August 31, 1988. The staff concludes that the corpensatory measures put in place by TVA adequately address the effects of excessive cooldown on shutdown margins and that no unresolved safety issue exists. Please note that this conclusion is limited to Unit 2 core 3 operation and to the restart of Unit 1 core 4 because TVA relies on operator action to compensate for known deficiencies in design or raintenance. The compensatory measures are acceptable for the short-term. TVA has stated that itThis will submit the details of its is acceptable.

long-tern program by October 14, 1988.

Further review and approval by the staff will be necessary for the long-tern operation of unit I core 4 and the restart of Unit 9 after the upcomino Cycle 3 refueling outage. The staff intends to evaluate your October 14, 198A submittal expediteously and will issue its evaluation in a separate letter.

This letter will address long-term creration of Unit 1 core 4 and the restart of Unit 2 from the Cycle 3 refuelino cutage.

Sincerely

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Original signed by Suzanne Black, Assistant Director for Projects Office of Special Projects Fnclosure:

Safety Evaluation report cc w/ enclosure: \

W next page ll ($o nes A/FM OSP:

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f,h\oO*y)y f& 7 o

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September 30, 1988

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v Docket Nos. 50-327/328 Distribution r Docket File MSimms NRC POR JRutberg FMiraglia

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Mr. S. Local PDR Senior Vice President, Nuclear Power OSP Reading 8. Gritnes !

Tennessee Valley Authority Projects Rdg. EJordan ,

6N 38A Lookout Place JPartlow ACRS(10)

1101 Market Street SRichardson GPA/PA ,

Cattanooga, Tennessee 37402-2801 BDLiaw GPA/CA '

i j FMcCoy SQN Rdg. File

Dear Mr. White:

JDonohew SUBJECT: CORE SHUTDOWN MAPGIN - SEQUOYAH NUCLEAR PLANf, UNITS 1 AND 2 i

! (TACSR00398,R00399)

By letter dated July 14, 1988, the Tennessee Valley Authority (TVA) submitted a Licensee Event Report (LER 50-32a/88-030) on the shutdown margin in the cores .

for Sequoyah Units 1 and 2. This LER applies to Unit 1 core 4 and Unit 2 ;

core 3 which are the current cores for the units. Unit 1 is preparing to begin i cycle 4 operation and Unit 2 is in cycle 3 operation. The nurr.ber assigned to ;

the core for each unit is the cycle the unit is currently in or preparing to

'

enter when the unit returns to power.

'

The staff conducted an inspection on this subject during July 11-14, 1988, !

reviewed the above LER and reviewed TVA's letter of August 31, 1988. The ,

staff cor.cludes that the compensatory measures put in place by TVA adequately

'

address the effects of escetsive cooldown on shutdown margins and that i no unresolved safety issue exists. Please note that this conclusion  ;

15 limited to Unit 2 core 3 operation and to the restart of Unit 1 core 4 because TVA relies on operator action to compensate for known deficiencies in design or maintenance. The compensatory measures are acceptable for  ;

the short-term. TVA has stated that it will submit the details of its long-tem program by October 14, 1988. This is acceptable.

Further review and approval by the staff will be necessary for the long-term operation of unit 1 core 4 and the restart of Unit 2 after the upcoming [

Cycle 3 refueling outage. The staff intends to evaluate your October 14,19s8 i submittal expediteously and will issue its evaluation in a separate letter. l This letter will address long-tem operation of Unit 1 core 4 and the restart r of Unit 2 fron the Cycle 3 refueling outage. [

Sincerely, f

i Original signed by [

!

Suzanne Black, Assistant Director [-

for Projects Office of Special Projects i

,

Enclosure: l Safety Evaluation Report  ;

cc w/ enclosure: p See next page A/PM OSP: e 0/P i ew SBlack t g/88 is9ff 88

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,

-2- Sequoyah Nuclear Plant Mr. S. A.' White

.

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cc: Regional Administrator, Region 11 General Counsel U.S. Nuclear Regulatory Comission Tennessee Valley Authority

' 400 West Sumit Hill Drive 101 Marietta Strcet N.W. i Atlanta, Georgia 30323  ?

E11 B33 Knoxville, Tennessee 37902 Resident Inspector /Sequoyah NP r Mr. R. L. Gridley c/o U.S. Nuclear Pegulatory Comission i Tennessee Valley Authority 2600 Igou Ferry Road ,

SN 157B Lookeut Place Soddy Daisy, Tennessee 37379 i i

Chattanooaa. Tennessee 37402-2801 Mr. Michael H. Mobley, Director :

Mr. John T. LaPoint t Tennessee Valley Authority Division of Radiolohical Health l Seouoyah Nuclear Plant T.E.R.R.A. Building 6th Floor P.O. Box 2000 150 9th Avenue North Soddy Daisy, Tennessee 37379 Nashville, Tennessee 37219-5404 ,

Mr. M. Ray Dr. Henry Myers, Science Advisor !

Tennessee Valley Authority Comittee on Interior Sequoyah Nuclear Plant and Insular Affairs ,

U.S. House of Representatives P.O. Box 2000 Washington, D.C. 20515

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Soddy Daisy, Tennessee 37379 Tennessee Valley Authority Mr. D. L. Williarr.s <

Tennessee Valley Authority Rockville Office i

400 West Sumit Hill Prive 11921 Rockville N ke W10 885 Sutte 402 Knoxville, Tennessee 3790? Rockville, Maryland 20852 County Judge Hamilton County Courthouse Chattanooga, Tennessee 37402