ML20084E103

AO 50-244/74-19:on 741204,during Surveillance Test PT-9, Undervoltage Relay 274/11B Failed to Operate.Caused by Scale Accumulation on Armature Plunger Opposite Upper Guide Bearing.Plunger Polished

ML20084E103
Person / Time
Site:	Ginna
Issue date:	12/13/1974
From:	White L ROCHESTER GAS & ELECTRIC CORP.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20084E106	List: ML20084E103
References
AO-50-244-74-19, NUDOCS 8304140097
Download: ML20084E103 (3)

Text

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Q_ 'n ROCHESNR GAS AND ELECT 9!C CORPORATICtl e 59 EAST AVENUE, ROCHESTER. N.Y.14629 LEOND W H 6TE. J H t t+.. ass v'Cg pe ts:CEP- ~

n ot 4 J e. . r e "'46 .'779 December 13, 1974 L i ,. ,

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.  ? 9ES{liQh, Mr. James P. C'Reilly, Director CE 000 "g[-;y;/374

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F Directorate of Regulatory Operations 7, Region I g t

, , "e.1 , y U. S. Atomic Energy Commission 2% -

Ny' 631 Park Avenue Wf g') 6 ['

King of Prussia, Pennsylvania 19406

Subject:

Abnormal Occurrence 74-19, Malfunction of Undervoltage Relay during surveillance test R. E. Ginna Nuclear Power Plant, Unit No.1 Docket No. 50-244

Dear Mr. O'Reilly:

In accordance with Technical Specifications, Article 6.6.2a, the attached report of Abnormal Occurrence 74-19 is hereby submitted.

Very truly yours ,

fY-L. D. White , Jr.

Attachment

$d ,

,pu he KGO4140097 741213 1232C  !

gDRADOCK 05000244 I PDR OCFY SENT REGION -

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, 3 AOP[50-244/74-19 co 2.

9. Corrective Action:

All four undervoltage relays were removed, one at a time, and the scale accumulation was removed and the plunger polished. Subsequent bench testing indicated freedom of movement of the plunger through the guide bearing without noticeable drag. Upon returning the devices to service, the applicable section of PT-9 procedure was performed to verify operability.

1 The Plant Cperations Review Committee convened on December 4,1974 and made the following recommendations:

a. Maintenance surveillance to clean and calibrate these devices should be increased to at Icast every six months. The , pres ent schedule for cleaning and calibrating these devices is at least every refueling shutdown.

b. Since relays 273 and 274 for each 4160 volt bus (llA and 11B) are ,

mounted in a common case, a spare relay assembly of this type should be available to place in service while maintenance is being .

performed on a particular pair of relays. This will prevent having to leave one train of the Reactor Trip Undervoltage logic in the W tripped mode during maintenance.

c. The RG&E Electric System Protectior. Engineer should review the possibility of changing the type of relay used for this application.

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10. Failure Data:

a. As noted in 7. above, there has been one other failure with this type of relay which occurred on May 7.9, 1973. This was reported as Abnormal Cccurrence 73-1 on June 8,1973.

b. Equipment Identification:

Manufacturer: -

Westinghouse Type: SV Style: 1876099 Range: 70-150 volts , 60 Hz i

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