ML20106F611

Forwards Proprietary & Nonproprietary WCAP-10690 & 10691, Technical Bases for Eliminating Large Primary Loop Pipe Ruptures as Structural Design Basis for Callaway & Wolf Creek Plants, & Application for Withholding

ML20106F611
Person / Time
Site:	Wolf Creek, Callaway, 05000000
Issue date:	10/26/1984
From:	Petrick N STANDARDIZED NUCLEAR UNIT POWER PLANT SYSTEM
To:	Harold Denton Office of Nuclear Reactor Regulation
Shared Package
ML19269A701	List: ML20106F611 ML20106F620 ML20106F636
References
SLNRC-84-125, NUDOCS 8410300317
Download: ML20106F611 (3)

Text

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l Standardized Nuclear Unit Power Plant System 5 Choke r.herry Road Nicholas A. Petrick j v land 20850 Executive Director October 26, 1984  ;

SLNRC 84-125 FILE: 0279 SUBJ: Request for Partial Exemption from Provisions of GDC-4 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Docket Nos: 50-482 and STN 50-483 Ref: (a) SNUPPS Letter SLNRC 84-0088, 05/31/84: Request for Partial Exemption from Provisions of GDC-4 (b) NRC Letter to Texas Utilities Generating Co. (TUGCo),

dated 3/2/84, Comanche Peak Steam Electric Station Units 1 and 2, Docket Nos. 50-445 and 50-446

Dear Mr. Denton:

The refe_rence (a) letter informed the NRC that SNUPPS was requesting the elimination of postulated pipe breaks in the RCS primary loop from the structural design basis of the Callaway and Wolf Creek plants.

As part of that letter, Westinghouse reports WCAP-10500 and WCAP-10501, ,

" Technical . _ Bases for Eliminating Large Primary Loop Pipe Rupture as Structural Design Basis for Callaway and Wolf Creek Plants" (both proprietary and non-proprietary versions) were enclosed. Those reports provided the type of information requested by the Staff for NRC review of the technical bases for elimination of RCS primary loop pipe breaks.

The reference (b) NRC letter indicated that the NRC Staff had reviewed (1) the leak-before-break analysis provided by TUGCo on their Comanche Peak docket, and (2) the generic Westinghouse report WCAP-10456 dealing with fracture toughness of piping materials under thermal aging condi-tions. As a result of that review, the Materials Engineering Branch (MEB) requested addicional information to complete its evaluation on the subject matter for Comanche Peak as well as for other applicants requesting a similar GDC-4 exemption. .

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' Page Two At a meeting held March 22, 1984, with representatives of the NRC Staff / Texas Utilities (representing the NT0L's)/ Westinghouse to review the Staff questions, the Westinghouse approach to addressing the MEB requests was presented and f avorably received by the NRC. On the basis of that meeting and subsequent communications with SNUPPS, Westinghouse has prepared responses to the referenced MEB request for additional information, specifically for the SNUPPS units as discussed below.

The purpose of this letter is to transmit 3 copies each of WCAP-10691 Westinghouse Proprietary, and WCAP-10690 (Non-Proprietary version of WCAP-10691), " Technical Bases for Eliminating Large Primary Loop Pipe Ruptures as the Structural Design Basis for Callaway and Wolf Creek Plants." WCAP-10691 is a new report (Proprietary and Non-Proprietary versions as appropriate) prepared specifically for the SNUPPS Units.

This new report incorporates the previous material in Westinghouse report WCAP-10500 along with the additional information addressing MEB Items 121.16, 121.17, 121.18, and 121.19. For Item 121.20, an

-assessment of margins considering the loads, flaw size, and material toughness for the Callaway and Wolf Creek RCS piping material is also included. Results covering the elastic-pl astic fracture mechanics analysis of the 4-inch thermally aged pipe in WCAP-10456 are essentially completed and have been handled on a generic basis between Westinghouse and the NRC.

Also enclosed is a Westinghouse authorization letter, CAW-84-93 and accompanying affidavit.

As WCAP-10691 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 addresses with specificity the considerations listed in paragraph (b)(4) of Scction 2.790 of the Comission's regulations.

Accordingly, it is respectfully requested that the information which is proprietary to Westinghouse be withheld from public disclosure in accordance with 10CFR Section 2.790 of the Comission's regulations.

Correspondence with respect to the proprietary aspects of the Applica-tion for Withholding or the supporting Westinghouse affidavit should reference CAW-84-93 and should be addressed to R. A. Wiesemann, Manager, Regulatory & Legislative Aff airs, Westinghouse Electric Corporation,

- P.O. Box 355, Pittsburgh, Pennsylvania 15230.

Your prompt review of the enclosed reports and action on our request for partial exemption from provisions of GDC-4 will be appreciated.

The schedule of the Wolf Creek plant is such that the schedule for processing of our request is critical to the decision as to whether

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' improved reactor- cavity shielding can be installed for startup testing and Linitial operations. . With respect to Callaway, the existing water bags for cavity shielding have proved troublesome and replacement with improved shielding at an early date .is' desirable.

Very truly yours, C

N cholas A. Petr?ck FS/bds/14a1

Enclosures:

1. _ 3 copies of WCAP-10691, " Technical Bases for Eliminating Large v'

Primary Loop Pipe Rupture as a Structural Design Basis for Callaway -

and Wolf Creek Plants," ' Westinghouse Proprietary Class 2,' October 1984.

2. 3 copies _ of WCAP-10690, " Technical Bases for Eliminating Large Primary Loop Pipe Rupture as a Structural Design Basis for Callaway and Wolf Creek Plants," Westinghouse Non-Proprietary, October 1984.

3. 1 copy of Westinghouse authorization -letter, CAW-84-93 and accompanying affidavit. -

cc: D. F. Schnell UE G. L. Koester KGE J. M. Evans KCPL-H. Bundy USNRC/WC J. Neisler/B. Little -USNRC/ CAL

~W.'L. Forney USNRC/RIII D. R.. Hunter USNRC/RIV-I