ML20076E141

Responds to NRC Inquiry Re Classification of Stresses by C-E in Potential Finding Rept 2448-011.Misclassification of Stresses Is Isolated Case,Based on Specific Method.No Generic Problem Indicated

ML20076E141
Person / Time
Site:	Waterford
Issue date:	08/17/1983
From:	Carpenter F TORREY PINES TECHNOLOGY
To:	Knighton G Office of Nuclear Reactor Regulation
References
TPT:064:FDC:83, TPT:64:FDC:83, NUDOCS 8308240155
Download: ML20076E141 (3)

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TORREY PINES TECHNOLOGY PO. Box 85608 San Diego, Cahfornia 92138 gp.372 Telephone: (619) 455-2654 A Dnnson of GA Technologies Inc.

TPr:064:FDC:83 August 17, 1983 Director of Nuclear Reactor Regulation Attention: Mr. George W. Knighton Chief, Licensing Branch No. 3 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D. C. 20555

Subject:

Docket No. 50-382 Louisiana Power & Light Company Waterford-3 SES Emergency Feedwater System Independent Design Verification

Dear Mr. Knighton:

The letter is in response to the NRC's inquiry concerning classification of stresses by Combustion Engineering (CE) in Potential Finding Report -

2448-011. This specific potential finding raised a concern of the stress intensity exceeding the requirements for the upper support lugs on the steam generator. TPT questioned the stress resulting from normal operating and OBE loading combination at the snubber lugs was incorrectly classified by CE as a combination of primary plus secondary stresses. This PFR was determined to be a valid observation because a substantial safety hazard did not exist. This judgment was made by the Findings Review Committee based upon detailed independent calculations by TPT engineers indicating allowables were not exceeded. In addition, the impact assessment by the task leader did not have evidence that multiple similar violations, discrepancies or errors were uncovered in the review of other portions of CE designed structures.

The review and judgment process was in compliance with the established procedure for processing of Findings (TPT Procedure 2448-PD-5).

NRC's concern resulted in a re-examination by TPT of data relating to CE's classification of stresses for other structures reviewed by TPT. The portion of CE designed structures selected for this independent design review of the emergency feedwater system included the steam generator upper support lugs (PFR-2448-011), the feedwater nozzle, lower support skirt, and the sliding base. This investigation established the fact that the method used to evaluate stresses in the upper support lugs was based on a paper published by Wichman, Hopper, and Mershan. This specific method was not 8308240155 830817 DR ADOCK 05000

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US NRC Attn: Mr. George W. Knighton 2 8/17/83 A

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the technique used in classification of stresses in the other three structures.

Stress analysis for these three other structures classified the stresses properly and the allowable for primary plus secondary stress intensity range

,l was properly applied.

This instance of what TPT considers to be a misclassification of stresses is an isolated case based on a specific method and no other instances were found. Thus based on TPT's scope of review, no generic problem is indicated.

Sincerely, Fred D. arpenter Project Manager Attached: Distribution List f

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Attachment to TPT:064:FDC:83 1

Distribution List Director of Nuclear Reactor Regulation Attention: Mr. George W. Knighton Chief, Licensing Branch No. 3 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D. C. 20555 Mr. T. H. Novak Assistant Director of Licensing U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Suzanne Black Licensing Project Manager U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Mr. R. H. Vollmer Director, Division of Engineering U.S. Nuclear Regulatory Commission j Washington, D.C. 20555 l

Mr. Les Constable j Resident Inspector, Waterford NPS U.S. Nuclear Regulatory Commission P. O. Box 822

Killona, LA 70066 Mr. W. Malcolm Stevenson, Esq.

Monroe & Lemann Attorneys and Counsellors at Law Whitney Building 228 St. Charles Avenue New Orleans, LA 70130 Mr. Ernest L. Blake, Jr.

Shaw, Pittman, Potts, & Trowbridge 1800 M Street, N.W.

Washington, D. C. 20036 Louisiana Power & Light Company 202 Huey P. Long Avenue Gretna, LA 70053 Attn: Kantilal Gala, Program Coordinator Waterford 3 SES l

Mr. J. T. Collins, Divisional Admin.

l Region 4 USNRC Suite 1000 - 611 Ryan Plaza Drive Arlington, Texas 76012 l

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