ML20213D679

Forwards Nonproprietary WCAP-11328 & Proprietary WCAP-11327, Cumulative Usage Factor Criterion for Break Postulation for South Texas Units 1 & 2, Per NRC 861022 Request.Proprietary Rept Withheld (Ref 10CFR2.790)

ML20213D679
Person / Time
Site:	South Texas
Issue date:	10/31/1986
From:	Wisenburg M HOUSTON LIGHTING & POWER CO.
To:	Noonan V Office of Nuclear Reactor Regulation
Shared Package
ML19292G221	List: ML20213D679 ML20213D701 ML20213D726
References
ST-HL-AE-1793, NUDOCS 8611120189
Download: ML20213D679 (4)

Text

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The Light NE Uf thiuston Lighting & Power PG. Ilox 1700 flouston, Texas 77001 (713)228-9211 1986 October 31'/93 ST-HL-AE-l File No.: G9.10 Mr. Vincent S. Noonan, Project Director PWR Project Directorate #5 U. S. Nuclear Regulatory Commission Washington, DC 20555 South Texas Project Units 1 and 2 Docket Nos. STN 50-498, STN 50-499 Responses to NRC Request For Additional Information on STP Position on Pipe Break Postulation Relative to Cumulative Usage Factor

References:

(1) Letter from M. R. Wisenburg (Hi4P) to H. L. Thompson (NRC) dated February 28, 1986 (ST-HL-AE-1611)

(2) Letter from M. R. Wisenburg (HIAP) to H. L. Thompson (NRC) dated August 14, 1986 (ST-HL-AE-1722)

(3) Letter from M. R. Wisenburg (HL&P) to V. S. Noonan (NRC) dated September 17, 1986 (ST-HL-AE-1758)

(4) Meeting Minutes of October 1, 1986 and October 15, 1986 from N. Prasad Kadambi (NRC) to HL&P dated October 22, 1986.

Dear Mr. Noonan:

I Pursuant to the additional documentation requested by the staff and documented in Reference (4), enclosed is additional information setting forth the South Texas Project (STP) position relative to use of an increased cumulative usage factor (CUF) for pipe break postulation. This additional justification is provided to supplement References (1), (2) and (3).

HL&P considers the use of CUF-0.1 for pipe break postulation currently specified in the SRP, to be extremely conservative for ASME Section III, Class l 1 piping fabricated using austinetic stainless steel and operated with fluid meeting PWR water chemistry specifications. The enclosed report demonstrates that extremely large margins exist for crack extension by fatigue even for an j enveloping piping system (a typical accumulator U ne) with a CUF of 0.6 which significantly envelopes the requested extension of CUF to 0.4.

For the enveloping accumulator line, a fatigue crack growth analysis at the worst location based on the stress and geometry was completed. The procedure for calculating fatigue crack growth is outlined in the enclosure and the applicable fatigue crack growth law is presented. The potential for g Ll/NRC/md Q , P O R~ TO $00 W fh f q LP0R , 6 jM 86111E0189 861031 , NO PDR ADOCK 05000498 A PDR b' b L

ST-HL-AE-1793 Houston Lighting & Power Company File No.: G9.10 Page 2 vibratory stressen to enhance fatigue crack growth is examined and shown not to be a contributing factor to crack growth in the Class 1 lines under discussion. For the enveloped accumulator line, an initial small crack is assumed present and growth evaluated until it goes thru wall on the pipe.

Full wall penetration is shown not to occur until 55 plant lifetimes have passed (over 2000 years). Therefore, an enveloping conservative case shows very large margins against a crack growing to significant size for butt welded austinetic stainless steel PWR Class 1 piping 2 inches and larger.

Based upon the enclosed additional justification for an increased CUF and current LBB analysis work in progress, HL&P considers that CUF-0.4 for break postulation is warranted. HL&P considers that this submittal satisfactorily completes docketing of all required information needed by the staff to provide a favorable response to the HL&P request.

Because Enclosure (1) contains information proprietary to Westinghouse Electric Corporation, the attached affidavit signed by Westinghouse management sets forth the basis on which the information may be withheld from public disclosure by the NRC in accordance with the requirements of 10CFR2.790(b)(1).

This affidavit addresses with specificity the considerations of 10CFR2.790(b)(4). Correspondence with respect to the proprietary aspects of the affidavit and Application for Withholding of Enclosure 1 should reference CAW-86-096 and should be addressed to R. A. Wiesmann, Manager Regulatory and Legislature Affairs, Westinghouse Electric Corporation, P. O. Box 355, Pittsburgh, Pennsylvania 15230.

If you should have any questions on this matter, please contact Mr. M. E. Powell at (713) 993-1328.

Very truly ou s, e

J M. R. Wise, urg Deputy Project Manage ABP/yd -

Enclosures:

(1) WCAP-ll327 " Cumulative Usage Fac or Criterion for Break Postulation for South Texas Units 1 and 2", Westinghouse Proprietary Class 2, October, 1986. (5 copies)

(Also enclosed is a Westinghouse authorization letter,, (CAW-86-096), Proprietary Information Notice, and accompanying affidavit).

(2) WCAP-11328, " Cumulative Usage Factor criterion for Break Postulation for South Texas Units 1 and 2," Westinghouse Proprietary Class 3, October, 1986. (5 Copies)

L1/NRC/md

Houston Lighting ac Power Company ST-HL-AE-1793 File No.: C9.10 Page 3 cc:

Hugh L. Thompson, Jr., Director A. Backus/J. E. Malaski Division of PWR Licensing - A City of Austin Office of Nuclear Reactor Regulatica P.O. Box 1088 U.S. Nuclear Regulatory Commission Austin, TX 78767 Washington, DC 20555 J. B. Poston/A. vonRosenberg Robert D. Martin City Public Service Board Regional Administrator, Region IV P.O. Box 1771 Nuclear Regulatory Commission San Antonio, TX 78296 611 Ryan Plaza Drive, Suite 1000 Arlington, TX 76011 Brian E. Berwick, Esquire Assistant Attorney Ceneral for

• N. Prasad Kadambi, Project Manager the State of Texas U.S. Nuclear Regulatory Commission P.O. Box 12548, Capitol Station 7920 Norfolk Avenue Austin, TX 78711 Bethesda, MD 20814 ,

i Lanny A. Sinkin Claude E. Johnson Christic Institute Senior Resident Inspector /STP 1324 North Capitol Street c/o U.S. Nuclear Regulatory Washington, D.C. 20002 Commission P.O. Box 910 Bay City, TX 77414 Oreste R. Pirfo, Esquire Hearing Attorney Office of the Executive Legal Director M.D. Schwarz, Jr. , Esquire U.S. Nuclear Regulatory Commission Baker & Botts Washington, DC 20555 One Shell Plaza Houston, TX 77002 Citizens for Equitable Utilities, Inc, c/o Ms. Peggy Buchorn J.R. Newman, Esquire Route 1, Box 1684 Newman & Holtzinger, P.C. Brazoria, TX 77422 1615 L Street, N.W.

Washington, DC 20036 Docketing & Service Section Office of the Secretary Director, Office of Inspection U.S. Nuclear Regulatory Commission and Enforcement Washington, DC 20555 U.S. Nuclear Regulatory Commission (3 Copies)

Washington, DC 20555 Advisory Committee on Reactor Safeguards T.V. Shockley/R.L. Range U.S. Nuclear Regulatory Commission Central Power & Light Company 1717 H Street P.O. Box 2121 Washington, DC 20555 Corpus Christi, TX 78403 l

• Includes attachments 1 & 2 All others without attachments L1/NRC/md Revised 10/09/86

f Attachment 1

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