ML20086S081

Interim Deficiency Rept Re Broken Capstan Spring Tangs on Pacific-Scientific Shock Arrestors.Initially Reported on 840126.Metallurgical Analysis Indicates Cracking Due to Stress Induced by Spring Forming.Next Rept by 840518

ML20086S081
Person / Time
Site:	Vogtle
Issue date:	02/23/1984
From:	Foster D GEORGIA POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
GN-321, NUDOCS 8403010354
Download: ML20086S081 (2)

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Jecrgia Power Cornpany

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L floute 2, Box 293A Waynesboro. Georga 30830 Telephone 404 554-9961. Ext 3360 404 724-8114, Ext. 3360 I

4FEBll Geoi ia Power p o. roster Vice President and General Mana r vogtie eroject ne scur*m ewinc system February 23, 1984 United States Nuclear Regulatory Camission File: X78G03-M54 Office of Inspection and Enforcement Log:

GN-321 Region II-Suite 3100 101 Marietta Street Atlanta, Georgia 30303

Reference:

Vogtle Electric Generating Plant-Units 1 and 2, 50-424, 50-425; Pacific-Scientific Shock Arrestors Attention: Mr. James P. O'Reilly Gentlemen:

On January. 26, 1984, Mr, C. W. Hayes, Quality Assurance Manager for the Vogtle Project, reported a potential deficiency to Mr. John Rogge of the USNRC-Region II. This potential deficiency concerned broken capstan spring tangs that may exist in certain models of~ Pacific-Scientific snubbers.

During testing of Pacific-Scientific Company's PSA-1 shock arrestors et the Callaway Station, four (4) of seven (7). snubbers tested revealed a broken capsti:n spring tang. Other snubbers from this lot were located at Wolf Creek and were returra.d to Pacific-Scientific for testing. After

. testing, the Wolf Creek snubbers exhibited micro-cracks in the tangs.

Pacific-Scientific also hcd a metallurgical analysis performed. This analysis indicated that spring cracking occurred because of stresses in-duced during-spring forming which caused hydrogen cracking during subsequent silver plating. This analysis also indicated that spring fracture was simplo ductile rupture which also accounts for the ability of the springs to with-

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stand full load functional and dynamic load testing.

In letters to Bechtel Power Corporation, Pacific-Scientific has indicated that they heve info:med and met with members-of the NRC concerning this subject.

OFFICIAL COW 84030f0354 840223 MZC PDR ADOCK 05000424

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' United States Nuclear Regulatory Commission

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' Pacific-Scientific Shock Arrestors Page-Two On the Vogtle Project, Pacific-Scientific has furnished PSA-1 and PSA-3 E

snubbers which may exhibit this concern. Pacific-Scientific has informed

-Georgia Power Company that curcently 85% of their snubbers are passing tests.

At this1 time, Georgia Power Company does not have a test schedule for our

" snubbers. Georgia Power Company will advise the NRC on, or about, May 18, fl984, when a final-report on this issue can be expected.

Yours tr:11y,

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D. 0. Foster ^"

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xc:.:U. S. Regulatory Commission Document Control Desk Washington, D.C.

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R. J. Kelly' J. A. Bailey R. E."Conway

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.G. F. Head G. Bockhold C..W. Hayes B. M. Guthrie

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