ML20085K709

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Interim Deficiency Rept U-63 Re Broken or Cracked Capstan Spring Tangs on Pacific Scientific Mechanical Snubbers. Initially Reported on 830916.Caused by Age Hardening Snubber Springs Prior to Plating.Final Rept by 831111
ML20085K709
Person / Time
Site: Callaway Ameren icon.png
Issue date: 10/14/1983
From: Schnell D
UNION ELECTRIC CO.
To: James Keppler
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
10CFR-050.55E, 10CFR-50.55E, U-63, ULNRC-673, NUDOCS 8310210098
Download: ML20085K709 (1)


Text

e.

hm6 UNION ELECTRIC COM PANY ISCO GRATIOT STREET ST. Louis, MISSOURI MAILING ADDRESS:

OQNALD F. SCHNELL P.O.SOM 948

. . . . . . ' ~ * " ' " ' ' ' " ' " " " ' " ' "

October 14, 1983 '

l Mr. James G. Keppler, Regional Administrator US Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, IL 60137 ULNRC- 673

Dear Mr. Keppler:

INTERIM 10CFR50.55(e) REPORT NO. U-63 CALLAWAY PLANT UNIT 1 On September 16, 1983 Union Elec'cric notified Mr. H.

Wescott of Region III of a deficiency reportable under 10CFR50.55(e) concerning broken or cracked capstan spring tangs on several Pacific Scientific Company mechanical snubbers. Mr. Wescott was informed that a final or interim report would be issued through the SNUPPS organization within 30 days. A SNUPPS generic report will be issued as the deficiency has been determined to exist additionally at the SNUPPS Wolf Creek Unit.

The deficiency has been determined to be caused by a single spring supplier's sequence of forming and age hardening of the snubber springs prior to plating. The sequence provides a potential for high residual stress in the formed radius of the tang coupled with hydrogen generated during the cleaning and plat-ing operation combining to produce hydrogen induced cracking.

This letter is to serve as an interim report on this deficiency as additional time is necessary to collect and assimi-late the information necessary for a final report. A final report will be submitted through the SNUPPS organization on behalf of Union Electric on or before November 11, 1983.

Very truly yours, Donald F. Schnell JJS/TPC/jds cc: J. E. Konklin, Region III Richard DeYoung, Director I&E NRC Resident Inspector, Callaway Plant Missouri Public Service Commission g AO gl7 i0 OCT 171983 8310210098 831014 PDR ADOCK 05000483 PDR S

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