ML20207M256

Interim Deficiency Rept DER 86-31 Re Loose Windings of Diesel Generator.Initially Reported on 861205.Defective Rotor Removed & Visually Inspected by Vendor.Pole Piece Fasteners re-torqued.Final Rept Delayed Until 870209

ML20207M256
Person / Time
Site:	Palo Verde
Issue date:	01/02/1987
From:	Haynes J ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	Kirsch D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
ANPP-39576-JGH, DER-86-31, NUDOCS 8701130128
Download: ML20207M256 (4)

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} .wa INTERIM REPORT - DER 86-31 POTENTIAL REPORTABLE DEFICIENCY i ARIZONA NUCLEAR POWER PROJECT  !

PVNGS UNIT 3 I. Potential Problem During normal maintenance of the Unit 3 Train B diesel generator (3E-PEB-G02), rotor unbalance was detected. It was discovered that the copper windings on one of the rotor poles had come loose.

Inspection of the other pole pieces of this~ generator did not locate any further problems of a similar nature. The vendor /

manufacturer attributed the probable cause of damage either to

improper resin six or improper application.

During rework of the defective pole it was discovered thal pole piece fasteners on Train B diesel generator were loose.

II. Approach To and Status of Proposed Resolution l A. The defective rotor was removed from the diesel generator and

visually inspected by the vendor (NEI Peebles) representative

! at the jobsite. It was observed that the two layers of the 1 coil associated with the defective pole were separated.

The preliminary evaluation was that the probable cause of this ,

separation was substandard bond of the resin on the rotor windings. >

J NEI Peebles confirmed that polyester resin from the same batch was used on the Unit 3 Train A and Train B diesel generator rotors and the spare rotor. Train A diesel generator has j successfully operated for over 140 hours0.00162 days <br />0.0389 hours <br />2.314815e-4 weeks <br />5.327e-5 months <br /> both loaded and l

unicaded. The Train B diesel generator has been run for three i

hours unloaded. Both diesel generators have been subjected to the overspeed trip verification. The Train A rotor poles, the remaining Train B rotor poles and the spare rotor poles were inspected and no discrepancies were noted.

. B. The pole piece fasteners on the Unit 3 Train B diesel generator i had been re-torqued to vendor recommended values.

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! C. The Units 1 and 2 diesel generators have approximately 700

. hours and 300 hours0.00347 days <br />0.0833 hours <br />4.960317e-4 weeks <br />1.1415e-4 months <br /> of operation respectively. The successful operation of both A and B trains of diesel generators in Units 1 and 2 during testing and Normal operation provide assurance that this is an isolated case. Therefore, there is no evidence that the Units 1 and 2 diesel generator rotors are affected by the same potential defect.

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III. Projected Completion of Corrective Action and Submiti:al of the Final Report The complete evaluation and final report are forecast to be completed by February 9, 1987.

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b Arizona Nuclear Power Project 597

" 'S P.O. BOX 52034 e PHOENIX, ARIZONA 85072-2034 January 2, 1937 k ANPP-39576-JGH/DJW/DRL- jr

,8g U. S. Nuclear Regulatory Commission Region V 1450 Maria Lane - Suite 210 Walnut Creek, California 94596-5368 Attention: Mr. D. F. Kirsch, Director Division of Reactor Safety and Projects Palo Verde Nuclear Generating Station (PVNGS)

Units 1, 2, 3 Docket Nos. 50-528, 529, 530

Subject:

Interim Report - DER 86-31 A 50.55(e) Potentially Reportable Deficiency Relating to Loose Windings of Diesel Generator File: 86-006-216

Reference:

Telephone Conversation between Jo Bianchi for R. C. Sorenson and D. R. Larkin on December 5, 1986 (Initial Notification -

DER 86-31)

Dear Sir:

The NRC was notified of a potentially reportable deficiency in the referenced telephone conversation. At that time, it was estimated that a determination of reportability would be made within thirty (30) days.

(January 5, 1987)

Due to the extensive investigation and evaluation required, an Interim Report is attached. It is now expected that this information will be finalized by February 9, 1987 at which time a complete report will be submitted.

Very truly yours,

! t &

J. G. Haynes Vice President Nuclear Production JGH/DRL/ dim Attachments cc: See Page 2

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JE-17

DER 86-31 Mr. D. F. Kirsch Director Page Two

. January 2, 1987 ANPP-39576-JGH/DJW/DRL-92.11 cc: J. M. Taylor Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D. C. 20555 A. C. Gehr (4141)

R. P. Zimmerman (6295)

Records Center Inst.itute of Nuclear Power Operations 1100 circle 75. Parkway - Suite 1500

. Atlanta, Georgia 30339 l

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