ML20082S822

Application for Amends to Licenses DPR-77 & DPR-79, Consisting of TS Change 90-01,incorporating New RCS Pressure Temp Limits Based on Reg Guide 1.99,Rev 2 Methodology

ML20082S822
Person / Time
Site:	Sequoyah
Issue date:	09/06/1991
From:	Joshua Wilson TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20082S825	List: ML20082S822 ML20082S828 ML20082S833 ML20082S836
References
RTR-REGGD-01.099, RTR-REGGD-1.099 TAC-79900, TAC-79901, NUDOCS 9109170309
Download: ML20082S822 (3)

Text

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September 6, 1991 l,

i: .TVA SQN-TS-90-01, R1 10 CFR 50.90 l'

U.S. Nuclear Legulatory Commission

ATTN

Doc ui. cnt Control Desk Washington, D.C. 20555 i'

Gentlemen:

In the Matter of ) Docket Nos. 50-327 Tennessee Valley Authority ) 50-328

SEQUOYAH NUCLEAR PLANT (SQN) - TECHNICAL SPECIFICATION (TS) CHANGE 90-01, l REVISION 1 (TAC-NOS. 79900 and 79901) l i

References:

1. TVA letter to NRC dated March 1, 199i, "3equoyah Nuclear l- Plant (SQN) - Technical Specification (TS) Change 90-01"

2. NRC letter to TVA dated May 23, 1991, " Request for Additional Information (RAI) - Technical Specification Change 90 Sequoyah Nuclear Plant, Units 1 and 2 (TAC Nos. 79900/79901)"

In accordance with 10 CFR 50.'0, we are enclosing a requested amendment to Licenses DFR-77 and DPR-79 to change the TSs of SQN Units 1 and 2.

The proposed change incorporates new reactor coolant system pressure temperature (P-T) limits that are based on NRC Regulatory Guide (RG) 1.99, Revision-2, methedology.

It should be noted that the enclosed information supersedes TVA's previous TS Change 90-01 provided in Reference 1. TVA reviewed calculations in response to NRC questions on TS Change 90-01 (Ref erence 2) and found an error, which af f ected TVA's calculated P-T limits. -Information on this error was verbally conveyed to NRC staff on April 23, 1991. The. error was a result of an assumption that the vessel forging material continued to be the controlling material as it had in

. previous calculations. In addition, the method of applying irradiation damage data for the tangential and axial directions for forging materials was changed to be consistent with the method applied by NRC. New P-T limits have now been generated by Westinghouse Electric Corporation. 4 4 9109170309 910906 ,\ I(

{DR ADOCK 05000327 POR s

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i 2-l U.S. Nuclear Regulatory Commission h September 6 1991 P

The Westinghouse calculations provided in Enclosure 4 address the NRC 1 questions contained in the Reference 2 letter. This approach to l addressing the Reference 2 questions was coordinated with NRC staff on i June 18, 1991.

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As a result Of TVA's update to SQN's P-T limits, TVA perf ormed a  ;

reassessment of SQN's reactor pressure vessel nil-ductility reference l temperatures for protection against pressurized thermal shock (PTS)  !

events (Enclosure 5). This reassessment was performed in accottance with NRC's recent amendment to 10 CFR 50.61, " Fracture Toughness seguirements t for Protection Against Pressurized Thermal Shock Events ," that was t published-in the Federal Register on May 15, 1991 (5bfR22300-22306). l TVA's assessment indicates that projected nil-ductility reference l temperature values:for both units do not exceed the PTS screening -

criterion (270 degrees Fahrenheit [F] for plates, forging, and axial weld  !

materials or 300 degrees F for circumferential weld material).  !

i The proposed TS change is identified in Enclosure 1. The justificat .n {

for the proposed TS change is provided in Enclosure 2. A proposed [

determination of no'significant hazards considerat;on perf ormed pursuant j to 10 CFR 50.92 is provided in Enclosure 3. The Westinghouse P-T ,

calculations-(WCAP-12970 for Unit I and.WCAP-12971 for Unit 2) are t

, provided in Enclosure 4 TVA's assessment of PTS performed pursuant to  :

10 CFR 50.61 is provided in Enclosure 5. {

i Please direct questions concerning this issue to D. V. Goodin at i (615) 843-7734 ,

-Very truly yours.

I TENNESSEE val. LEY AUTHCRITY V

h G L-J/ L. Wilson  !

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L sworn tg"and subscribed before me [

this b day of $gf_prjtttg 1991  :

, t OA4 0LYM b U- '

-Notary / Pub'lic l k '[- 9 JL

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My Ccmmission. Expires {

Enclosures [

cc: _See page 3 {

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U.S. Nuclear Regulatory Commission September 6, 1991 ec (Enclosures);

American Nuclear Insurers Attention: Librarian  !

The Exchange, Suite 245 270 Farmington Avenue l Farmington, Connecticut 06032 L Mr. D. E. LaBarge, Project Manager l U.S. Nuclear Regulatory Commission [

One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852  ;

Mr. Michael H. Mobley, Director (w/o Enclosures)

Division of Radiological Health T.E.R.R.A. Building  !

150 9th Avenue, N Nashville, Tennessee 37203 '

NRC Resident Inspector Sequoyah Nuclear Plant  ;

2600 Igou Ferry Road Soddy Daisy, Tennessee 37379 Mr. B. A. Wilson, Project Chief U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323

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