ML20135B815

Forwards non-proprietary & Proprietary Versions of RCS Flow Verification Using Elbow Taps at Westinghouse 3-Loop PWR & Affidavit Which Sets Forth Basis on Which Info May Be Withheld from Public Disclosure

ML20135B815
Person / Time
Site:	Farley
Issue date:	11/26/1996
From:	Dennis Morey SOUTHERN NUCLEAR OPERATING CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML19310D721	List: ML20135B815 ML20135B822 ML20135B826
References
NUDOCS 9612060051
Download: ML20135B815 (3)

Text

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D:ve Morey S:uthern Nuclear Vice President Op:ra7ng Company farley Project R0. Box 1295 Birmingham. Alabama 35201 Tel 205.992.5131 SOUTHERNkL i

J COMPANY Energy to Serve YourWorld" November 26, 1996 Docket Nos.: 50-348 50-364 U. S. Nuclear Regulatoiy Commission ATTN: Document Control Desk Washington, DC 20555 i

Joseph M. Farley Nuclear Plant Request for NRC Staff Review of WCAP-14750 "RCS Flow Verification Usine Elbow Taps at Westinnhouse 3-Loon PWRs" Ladies and Gentlemen:

Southern Nuclear Operating Company is submitting a Westinghouse Owners Group (WOG) technical report, WCAP-14750, "RCS Flow Verification Using Elbow Taps at Westinghouse 3-Loop PWRs," for NRC Staff review and approval. The elbow tap flow measurement method provides an alternate method for satisfying the Technical Specifications eighteen month RCS total flow surveillance. This report is applicable to other 3-loop Westinghouse PWRs for which Farley is the lead plant.

An alternate RCS flow measurement method is necessary because ofinherent limitations associated with the calorimetric-based method in PWRs with extreme low leakage core loading patterns. In recent operating cycles, Farley, along with other 3-loop PWRs, has experienced apparent reductions in RCS flow rate that have been attributed to variations in hot leg streaming, which have been exacerbated by the low leakage core designs. This apparent flow reduction occurs because the temperature measurements used in the precision calorimetric-based method are l influenced by hot leg temperature streaming effects. While RCS flow surveillance using cold leg ethow tap measurements normalized to early cycle calorimetric flow measurements may have larger instrumentation uncertainties, the elbow tap measurements are not sensitive to the hot leg streaming variations. Independent confirmation of the elbow tap flow measurements has been ,

l obtained by performance of cycle-specific RCS hydraulic analysis. I I

9612060051 961126 I APD l PDR ADOCK 05000348 PDR

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% s_ _ a U. S. Nuclear Regulatory Commission Page 2 The elbow tap flow measurement procedure and recommended Technical Specifications changes are included in the attached Westinghouse reports: WCAP-14750 (Proprietary Class 2C) and WCAP-14754 (Proprietary Class 3), "RCS Flow Verification Using Elbow Taps at Westinghouse 3-Loop PWRs." The attachments also include Westinghouse authorization letter CAW-96-1015 and accompanying affidavit, proprietary information notice, and cop > Tight notice. As WCAP-14750 contains information proprietary to Westinghouse Electric Corporation, it is supported by an affidavit signed by Westinghouse, the owner of the information. The affidavit sets forth the basis on which the information may be withheld from public disclosure by the Commission and specifically addresses the considerations listed in paragraph (b)(4) of Section 2.790 of the Commission's regulations. Correspondence with respect to the copyright or proprietary aspects of the items listed above or the supporting Westinghouse affidavit should reference CAW-96-1015 and should be addressed to Nicholas J. Liparulo, Manager of Regulatcy & Engineering Networks, Westinghouse Electric Corporation, P. O. Box 355, Pittsburgh, Pennsylvania 15230-0355.

If you have any questions, please advise.

Respectfully submitted, SOUTHERN NUCLEAR OPERATING COMPANY

$ Aku Dave Morey resflow5.mge Attachments cc: Mr. S. D. Ebneter Mr. T. M. Ross ,

Mr. J.1. Zimmerman )

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ATTACHMENTS i

l Westinghouse letter CAW-96-1015, dated September 26,1996, " Application For Withholding Proprietary Information From Public Disclosure," with the following enclosures: Affidavit, Proprietary Information Notice, and Copyright Notice.

, Westinghouse WCAP-14750 (Proprietary Class 2C) "RCS Flow Verification Using Elbow Taps l l at Westinghouse 3-Loop PWRs."  !

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l Westinghouse WCAP-14754 (Non-Proprietary Class 3) "RCS Flow Verification Using Elbow Taps at Westinghouse 3-Loop PWRs."

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