ML19352A002

Final Deficiency Rept Re Damaged Insulation on Stator Coils of B Diesel Generator Set,Initially Reported 800723.Cause Unknown.Stator Coils Returned to Transamerica Delaval,Inc for Repair

ML19352A002
Person / Time
Site:	Grand Gulf
Issue date:	12/17/1980
From:	Mcgaughy J MISSISSIPPI POWER & LIGHT CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
10CFR-050.55E, 10CFR-50.55E, AECM-80-312, NUDOCS 8102250345
Download: ML19352A002 (2)

Text

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MISSISSIPPI POWER & LIGHT COMPANY

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. f~ 20 "ja"ErTTN7ehf' December 17, 1980 Office of Inspection & Enforcem'ent U. S. Nuclear Regulatory Commission yt -

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101 Marietta Street, N.W. I Suite 3100 1 '

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Atlanta, Georgia 30303 /q Qg 'g fIU d Attentiin: Mr. J. P. O'Reilly, Director 3 u,#?N*g %cry ss "l P n i198] *

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Dear Mr. O'Reilly:

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SUBJECT:

Grand Gulf Nuclear Statio N'l'T

- Units 1 and 2 Docket Nos. 50-416/417 File 0260/15525/15526 PRD-80/33, Final Report, Damaged Stator Coil AECM-80/312

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Reference:

AECM-80/162, 7/23/80 On June 23, 1980, Mississippi Power & Light notified Mr. T. Bur-dette of your office of a Potentially Reportable Deficiency (PRD) at the Grand Gulf Nuclear Station (GGNS) construction site. The defi-ciency concerns damage to the stator coils of the generator for the Unit 1 "B" standby diesel generator. The subject diesel generator supplies emergency electrical power to safety-related equipment from Division II of the plant ESF power system.

We have determined that this deficiency is reportable under 10CFR50.55(e). This deficiency is not reportable under 10CFR21 since the generator had not been presented to MP&L for acceptance. Our final report is attached.

< Yours truly, J. P. McGaughy, Jr.

EWC:st 0 d Attachment hI cc: Mr. N..L. Stampley Mr. Victor Stello, Director Mr. R. B. McGehee Division of Inspection & Enforcement Mr. T. B. Conner U. S. Nuclear Regulatory Commission Washington, D.C. 20555 810 2250345- .

OFFICfhNOPV S Member Middle South Utilities System

O Attachment to AECM-80/312 Page 1 of 1 FINAL REPORT FOR PRD-80/33 I. Description of the Deficiency Mississippi Power & Light notified the NRC on 6/23/80 of Poten-tially Reportable Deficiency 80/33, concerning damages to the insulation on the stator coils of the Unit 1 "B" diesel generator set. The damage consists of a small crater type penetration of the insulation deep enough to display the bare copper of the coils and measuring approximately 3/8 inch wide and 3/4" long. The damage was from a unknown cause and was incurred during the absence of the stator covers for an execssive time duration.

The generator was supplied by Transamerica DeLaval Inc.

II. Analysis of Safety Implications Due to exposure of the stator coil, the damage could have led to failure of the generator. Failure of the generator to perform during a plant shutdown could affect the safety operations of the plant as the diesel-generator supplies power to equipment required for the safe shutdown of the plant. Therefore, this deficiency satisfies the conditions of 10CFR50.55(e), paragraphs 1 and 111.

III. Corrective Actions Taken The stator coil has been returned to the supplier for repair.

Action to preclude recurrence has been accomplished by adding a general note to the work instructions stating that the stator coil cover shall remain in place when the. stator is not being worked on.

Other actions necessary to correct the discrepant condition are I delineated in the Constructor's Management Corrective Action Report l (MCAR) Number 86.

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