ML19350E898

Interim Deficiency Rept 3 Re Vendor Wiring Problem in Size 3 Starters,Initially Reported 801111.Klockner-Moeller Will Inspect Each safety-related Starter Breaker for Power Cable Damage.Final Rept Expected by 811015

ML19350E898
Person / Time
Site:	Grand Gulf
Issue date:	06/15/1981
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-81-207, NUDOCS 8106230629
Download: ML19350E898 (5)

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F-MISSISSIPPI POWER & LIGHT COMPANY 1 Helping Build Mississippi k RhthNdds P. O. B O X 16 4 0. J A C K S O N. MIS SIS SlP PI 3 9 2 0 5 J^g g g j f June 15, 1981 Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission i Region II ,

101 Marietta Street, N.W.

Suite 3100 Atlanta, Georgia 30303 Attention: Mr. J. P. O'Reilly, Director -

SUBJECT:

Grand Gulf Nuclear Station Units 1 and 2 Docket Nos. 50-416/417 File 0260/15525/15526 PRD-80/69, Interim Report No. 3 Vendor Wiring Problem in Size 3 Starters AECM-81/207

References:

1) AECM-80/305, 12/11/80

2) AECM-81/126, 3/30/81 '

On November 11, 1980, Mississippi Power & Light Company notified Mr. P. .

J. Kellogg, of your office, of a Potentially Reportable Deficiency (PRD) at the Grand Gulf Nuclear Station (GGMS) construction site. The deficiency concerns electrical faults in size 3 starters supplied by Klockner-Moeller.

As we reported in reference 1, this deficiency was determined to be reportable under 10CF250.55(e). An interim report on this matter is attached.

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

g>, g i EWC:dr l ATTACHMENT /f cc: See page 2 S

8106230h/7 Member Middie South utiiities system

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' Mr. J. P. O'Reilly ~

. AECM-81/207 NRC Page 2 cci Mr. N. L. Stampley Mr. R. B. McGehee

Mr. T. B. Conner Mr. Victor Stello, Director - . ,

' Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission

. Washington,.D.C. 20555

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Mr. C..B. Taylor .

South Miss. Electric Power Association P. O. Box 1589 Hattiesburg, MS 39401 4

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>" bec: Dr. D. C. Gibbs Mr. J. N. Ward-Mr. J. P. McGaughy, Jr.

I Mr. W. A. Braun Mr. R. Trickovic Mr. J. W. Yelyneton Mr. L.-F. Dale Mr. C. K. McCoy Mr. T. H. Cloninger Mr. R. A. Ambrosino -

9 Mr. R. C. Fron Mr. G. _B. RcgerF Mr. M. R. Willi Mr. L.-E. Ruhland Mr. D. 1,. Hunt -

Mr. A. G. Wagner Mr. P. A. Taylor Mr. J. R. Valdez Mr. A. Niespeling Mr. B. C. Ime PRD File

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Attachment to AECM-81/207 y Page 1 of 2 IlfrERIM REPORT NO. 3 FOR PRD-80/69 I. Description of the Deff , acy The deficiency concerns an electrical wiring problem in size 3 starters supplied by Klockner-Moeller. The cables at the p' ser stab terminat. ion ,

have been pinched by the bus barrier and abraded 1.. varying degrees ranging from surface scratches to complete baring of the copper con-ductors. The system affected is the Standby-Liquid Control System (C41). ,

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In the most severe en.se, one conductor was shorted out it, a breaker, .

resulting in a flash fire in that cubicle, with permanent damage to the steel barrier. A fault in this location could result in a trip to the l~

incoming ieeder breaker to the Motor Control Center (MCC), causing a loss of power to all loads -fed from the MCC. Had this accident occurred coincidentally with e. loss of coolant accident (LOCA), the divisional loads cf the MCC (one trait ) would have been lost; thus a safe shutdown of the plant may not be assured.

The manufacturer reported this condition to the NRC under 10CFR21 on March 13, 1981. Determination of 10CER21 applicability to MP&L is cur-rently under invescigation.

II. Approach to Resolution of the Probles This condition uas caused by the improper length of "A" phase wire which extended above the stab before being bent away from the partition, tesulting in abrasion of the insulation every time the breaker was racked in or out.

i The Constructor will inspect each safety-rt4ated MCC starter / breaker for damage to the power cable' or qualify the starter / breaker by testing.

Damage will be repaired or replaced by our Constructor's fhid engineer-ing organization as deemed necessary.

III. Status of Proposed Resolution .

Representatives of the vendor and our Consttactor met in March,1981 and performed a sampling inspection on starcer/ breakers. It was concluded that tha larger size starters and the breakers with #4 wire had the most potential for failure. (The #4 wire is physically larger than the #8, causing it to require more space and to be more prone to pressing on the

, barrier. It is also less flexible, so it will not readily bend out of the way.) These units will require inspection and rewotk. The results of the inspection of the smaller size starters with #8 wire indicated that the failure. potential was less severe and perhaps nonexistent. l i: However, in the absence 7f a full inspection, objective evidence was required to demonstrate the adequacy of the smaller size starters. l 1

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• 7 Attachment to AECM-81/207 Page 2 of 2 Klockner-Moeller proposed that they conduct a life test (qualification test) on a sample _ of this group of starters. Success of the test would demonstrate that these units can operate through their service life plus a seismic event and need not be subjected to immediate inspection. The life test is scheduled for completion by July 31, 1981. .

The constructor's inspection program is underway. In order to conduct repairs and/or replace components, de-energization of the system is required. This inspection will be completed prior to fuel load. -

IV. Reason Why A Final Report Will Be Delayed Until the results of the vendor's life test is known, complete corrective actions cannot be established.

V. Date When Final Report Will Be Submitted It is anticipated that a final report can be submitted by October 15, 1981.

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