ML20084E111
| ML20084E111 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 12/05/1974 |
| From: | Platt C ROCHESTER GAS & ELECTRIC CORP. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| Shared Package | |
| ML20084E113 | List: |
| References | |
| AO-50-244-74-19, NUDOCS 8304140107 | |
| Download: ML20084E111 (1) | |
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_y ROC ll ESTER GAS AND ELECTRIC CORPORATION o 69 EAST AVGNUE..iOCHESTER. H.Y.14M9 T c L E P**ON I aata coot tie 546 2700 Ginna Station December 5, 1974 Mr. James P. O'Reilly, Director l
Directorate of Regulatory Operations Region 1 y
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U. S. Atcmic Energy Cc= mission
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i 631 Park Avenue k
King of Prussia, Pa.
19406
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Subject:
Abnormal Occurrence 74-19: Failure of Undervoltage Belay During k
Monthly Surveillance Test
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Ginna Station Docket #50-244 t
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Dear Mr. O'iicilly:
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During the pcrformance of the Monthly Serveillance Procedure PT-9, "Under-voltage and i'nderfrequency Protection" on Dcccaber 4, 1974, upon opening the knife switches for the solenoid coil of primary undervoltage device 274/118. It was discovcred that tne device armature did not irop down to asswae its' de-caergized position. As a result of this f ailure to operate, the Reactor Trip Undervoltage Protection sir,nal was not generated for this i
relay. The knife switches were it=ediately opened again, an<' this second l
t'ime the relay operated properly.
The other thrce undervoltage relays on the 4160 volt bus were tested and they operated properly.
RG&E Relay Department was contacted and a relay can came to the station to l
Investigate the failure.
4 f
A scale accumulation was noted on the armature plunger opposite the area of the upper guide bearing.
Thi accumulation uas similar to that reported as l
abnormal occurrence 73-1 on May 29, 1973.
All four undervoltage relays were removed, cac at a tire, and the scale accumulation was removed and the plun-l ter polished.
Upon returning the devices to service, the applicable sect' ion l
of PT-9 procedure was performed to verify operability.
f Very truly yours, g41401oy741213
/bi Y~
ADOCK 05000244 S
Charles E. Platt PDR Superintendent cc:
Mr. J. F. O' Leary, AEC
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//>yk "t. 2,.i v.L Mr. G. J. Swarthout, RC&E
$ J Hr. L. D. L'hite, Jr. RG&E
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