ML20116M357

TS Change 92-13 to Licenses DPR-77 & DPR-79,changing TS to Reduce Min RCS Total Flow Rate Requirement in TS 3.2.5 from Greater than or Equal to 378,400 Gpm to Greater than or Equal to 375,000 Gpm,Per Westinghouse Calculations

ML20116M357
Person / Time
Site:	Sequoyah
Issue date:	11/16/1992
From:	Joshua Wilson TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20116M358	List: ML20116M357 ML20116M360
References
NUDOCS 9211200209
Download: ML20116M357 (2)

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I November 16, 1992 TVA-SQN-TS-92-13 10 CFR 50.90 U.S. Nuclear Regulatory Commission ATIN: Document Control Desk Washington, D.C. 20555 Centlement In the Matter of ) Docket Nos. 50-327 Tennessee Valley Authority ) 50-328 SEQUOYAll NUCLEAR PLANT (SQN) - TECIINICAL SPECIFICATION (TS) Cl!ANGE 92-13 "RF'CTOR COOLANT SYSTEM (RCS) MINIMUM FLOW RATE REQUIREMENT REDUCTION" In accotdance with 10 CFR 50.90, we are enclosing a requested amer.Jment to Licenses DPR-77 and'DPR-79-to change the TSs of SQN Units 1 and 2.

The proposed change will reduce the minimum RCS total flow rate J requirement in TS 3.2.5. Table 3.2-1, from greater than or equal to 378,400 gallona per minute (gpm) to greater than or equal to 375,000 gpm. .This change is based upon accuracy calculations performed by Westinghouse Electric Corporation that support using a 2.4 percent flow measurement ancertainty for SQN instead of the generic 3.5 percent uncertainty utilized for initial licensing. The footnote associated with the RCS total flow rate value in TS Table 3.2-1 is also revised to-reflect the 2.4 percent flow measurement uncertainty.

The proposed TS change is identified in Enclosure 1. The justificatirn for the proposed TS change is provided in Enclosure 2. A proposed ,

determination of no significant hazards consideration performed pursuart to 10 CFR 50.92 is provided in Ei.losure 3.- The Westinghouse evaluations that support this change are provided in Enclosure 4.

The margin between the' currently calculated RCS total flow rates and the.

present TS limiting value is less than one percent for both SQN Units-1 and 2. Changes in the methods for calculating RCS flow rates in combination with the flow reductions associated with steam generator tube 190010 piugging ano reactor cooiant pump impeller wear have affected the calculated margin at SQN over time. -For this' reason, while not definitely required, TVA requests NRC review and approval of the proposed change to eliminate excessive measurement uncertainty before the end.of 3g the upcoming SQN Unit.1 Cycle 6 refueling outage to ensure the ability to ) ) l 9211200209-921116 \ l PDR ADOCKc05000327  ;

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U.S. Nuclear Regulatory Conunissior.

Page 2 November 16, 1992 enmply with the TS requirements for minimum RCS flow rate. NRC approval by the end of A,ril1 1993 would ensure the availability of this relaxation for the next performance of the 18-month survsi? lance for RCS flow rate as required by TS 4.2.5.2.

'IVA requests a 30-day implementation period for thh. TS change following issuance.

Please direct questions concerning this issue to K. C, Weller at (615) 843-7527.

Sincerely, h At gL. Wilson ripedbefgreine Sworn this / h_today ai dofsubs {gMerd&1992 f xia b kAn Notary Public My Conunission Expires .3-7Mb Enclosures cc (Enclosures):

Mr. D. E. LaBarge, Project Manager U.S. Nuclear Regulatory Conunission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852-2739 Mr. Michael H. Mobley, Director (w/o Eaclosures)

Divialoa of Radiological llcalth 3rd Floor L & C Annex 401 Church St eet Nashville, Ttunessee 37243-1532 x

NRC Resident Inspector Seo.syah Nuclear Plant to00 Igou Ferry Road Soddy Daisy. Tennessee 37379-3624 Mr. B. A. Wilson, Project Chief U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323-0199 i

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