ML19208A516

Submits Addl Info to 790814 Interim Rept of Potentially Reportable Deficiency 79-11 Re Cracked Control Device Assemblies,In Response to NRC 790827 Request.Decision Re Reportability to Be Made by 791130

ML19208A516
Person / Time
Site:	Grand Gulf
Issue date:	08/30/1979
From:	Dale L MISSISSIPPI POWER & LIGHT CO.
To:
References
AECM-79-99, NUDOCS 7909140440
Download: ML19208A516 (3)

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-Y MISSISSIPPI POWER & LIGHT COMPANY

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k Helpong Build Mississippi 2" S M_ P. O. B O X 16 4 0, J A C K S O N, MI S S I S S I P P I 39205

. c o u ctio ~ o ce.o r o e s t August 30, 1979 Office of Inspection and Enf orcement U. S. Regulatory Commissian Region II 101 Marietta Street, TW, Suite 3100 Atlanta, Georgia 30303 ATTENTI0'i: Mr. J. P.~ 0 'Reilly, Director Gen tlemen :

SUBJECT:

Grand Gulf Nuclear Station File 0272/0498/15525 Suppleme:.tal Information for Potentially Reportable Deficiency No. 79/11 AECM-79/99 As requested by your Mr. Floyd Cantrell on August 27, 1979, the following information is provided to supplement our interim report transmitted on August 14, 1979.

The inspection of control device assemblies revealed the following data:

e y Crocked Devices VS Insoccted

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Tvoe of Ecuinment Unit 1 Unit 2 6.9 KV Switchgear 15 of 18 20 of 20 4.16 KV Switchgear 36 of 75 69 of 69 480 Volt Load Centers 16 of 214 20 of 137 Totals 67 of 307 109 of 226 Attached is a page from ITE Bulletin RP-9.1.8-1, showing the control device assembly (item 8A) . The picture has been annotated to show the location of the cracks. 'These are vertical cracks ranging in length from h" to 1".

Gould-ITE is presently conducting " life-testing" of the devices to determine cause and significance. When testing is completed the results will be evaluated to determine significance.

950003 Member Middle South Utilities System 7909140 %(o #

MISSISSIPPI POWEtt & LIGHT COMPANY Mr. J. P. O'Reilly, Director AECM-79/ 99 U. S. Nuclear Regulatory Commission. Page 2 '

As indicated in our previous letter, we expect that a decision on reportability would be made by November 30, 1979.

Yours truly, 7

L. F. Dale Nuclear Project M nager ATR:lb Attachment ec: Mr. N. L. S tamploy bcc: Dr. D. C. Gibbs Mr. R. B. McGehee Mr. Adrian Zaccaria Mr. 'T. B . Conner Mr. J. N. Ward Mr. D. M. Lake Mr. John 'C'.\Davis, Directo4 THIS COPY F09 Mr. R. L. Scott Division of 1% pection & Enforcement Mr. J. P. McGaughy U. S. Regulatorffommission Mr. W. L. Nail Washington, D. C. '40555 Mr. T. E. Reaves

'N ' Mr. J. C. Fuller Ms. E. W. Chumley

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