ML20066H620

Submits Info Re RTD Bypass Elimination & Steam Generator Tube Plugging to Support 901026 Application for Amend to License NPF-2,per 910207 Telcon W/Nrc & Westinghouse

ML20066H620
Person / Time
Site:	Farley
Issue date:	02/15/1991
From:	Hairston W ALABAMA POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20066H625	List: ML20066H620 ML20066H627
References
NUDOCS 9102210214
Download: ML20066H620 (2)

Text

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. Alcama Power Company

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Nudear Opetahans Mgh3mg gg-eesw en<m eso m Docket No. 50-348 U. S. Nuclear Regulatory Comatission ATIN: Document Control Desk washington, D.C. 20555 Gentlemen:

Joseph M. Farley Nuclear Plant - Unit 1 hTD Bypass Elimination and Steam Generator Tube Plugging Amendment By letter dated October 26, 1990, Alabama Power Company submitted a technical specification amendment to support implementation of the RID Bypass Elimination modification and an increased steam generator tube plugging limit for Farley Nuclear Plant Unit 1. To account for a seismic allowance term which had been inadvertently omitted from the overtemperature AT setpoint uncertainty calculation, Alabama Power Company letter dated January 31, 1991 provided s changed technical specification page (2-10) to replace the original proposed change.

In a telephone conference call between Alabama Power Company, Westinghouse and the NRC on February 7, 1991, the NRC requested that the proposed DNB limit for Reactor Coolant System (RCS) total flow rate be changed to r.ccount for feedwater system flen venturi fouling. The flow venturis are used to develop feedwater flow data for the secondary calorimetric which is used in the eighteen month RCS total flow measurement surveillance. WCAP 12613, Revision 2, (proprietary) and WCAP 12614, Revision 2, (non-proprietary) provided the basis for the Farley specific RCS total flow rate uncertainty including flow calorimetric instrumentation uncertainties and sensitivities. The uncertainty calculations did not account for a venturi fouling uncertainty factor because the Farley feedwater flow venturis are inspected (and cleaned if necessary) every refueling outage.

However, as a conservative measure Alabama Power Company will include an additional 0.1% RCS flow uncertainty bias as recommended by the NRC to account for the uncertainty associated with the potential for feedwater flow venturi fouling. As such, the DNB limit for RCS total flow rate on technical specification page 3/4 2-15 must be changed. The changed replacement page is attached. The change includes a total 2.3% flow uncertainty (versus the original proposed 2.2%) and annotates that 0.1%

uncertainty bias is included to account for feedwater flow venturi fouling.

9102210214 910215 [/ g DR ADOCK0500gg8

U. S. Nuclear Regulatory Comission ATIN: Document Control Desk It should be noted that Alabama Power Company plans to pursue the issue of feedwater flow venturi fouling uncertainty as it applies to RCS flow measurement at Farley Nuclear Plant. Assuming that an adequate technical basis can be developed, Alabama Power company may request that the venturi fouling uncertainty bias be removed in the future.

Alabama Power Company has reviewed the significant hazards evaluation provided with the-license amendment submitted on October 26, 1990. The conclusions of the significant hazards evaluation remain valid and no changes are considered necessary. With the submittal of this changed page the NRC is therefore requested to approve the Unit 1 RTD Bypass Elimination and 15% tube plugging amendment as soon as possible to support implementation of the modification in the upcoming outage which is scaeduled to start March 8, 1991.

Alabama Power Company's Plant Operations Review Committee has reviewed the proposed change and the Nuclear Operation Review Board will review the change at a future meeting. A copy of this proposed change is being sent ,

to Dr. C. E. Fox, the Alabama State Designee, in accordance with 10 CrR ,

50.91 (b)(1).

If there are any questions, please advise.

Respectfully submitted, ALABAMA POWER COMPANY DbtAd WJ3 Hairston, III WGH/MGEssf$33.19 Attachment  !

SWORN 'IO AND SUBSCRIBED BEFORE ME cet Mr. S. D. Ebneter Mr. S. T. Hoffman THIS /P ADAY OFpIA,a,[,1991 Mr. G. F. Maxwell -

,p /

Dr. C. E. Fox [ / _ c [<o 4 A v7 e &

' Notary /Public My Comission Expires <7/N[99

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