PNO-I-99-046, on 991008,NMP,Unit 1 Declared Unusual Event,Due to Carbon Dioxide Discharge in Records Storage Room of Administration Bldg,Which Was Migrating Beyond Confines of Storage Room.Nrc Resident Inspector Staff Responded

PNO-I-99-046:on 991008,NMP,Unit 1 Declared Unusual Event,Due to Carbon Dioxide Discharge in Records Storage Room of Administration Bldg,Which Was Migrating Beyond Confines of Storage Room.Nrc Resident Inspector Staff Responded

ML20217B622
Person / Time
Site:	Nine Mile Point
Issue date:	10/08/1999
From:	Cook W, Marilyn Evans NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
References
PNO-I-99-046, NUDOCS 9910120316
Download: ML20217B622 (1)

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4 October 8, 1999 PRELIMINARY NOTIFICATION'OF EVENT OR UNUSUAL OCCURRENCE PNO-I-99-046 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially received.without verification or evaluation, and is basically all that is known.by' Region I staff in King of Prussia, Pennsylvania on this date.

EAcility Licensee Emeraency Classification Niagara Mohawk Power Corp. Notification of Unusual Event Nin6 Mile Point 1 Alert Lycoming,NewLYork- Site Area Emergency

. Dockets: 50-220 General Emergency X Not Applicable

Subject:

UNUSUAL EVENT DECLARATION DUE TO CARBON DIOXIDE DISCHARGE IN ADMINISTRATION BUILDING At 9:05 a.m. on October 8, 1999, Niagara Mohawk Power Corporation (NMPC)

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Unit 1 declared an Unusual Event due to a carbon dioxide discharge in the records storage. room of the administration building which was migrating beyond the confines of the storage room. The plant staff detected carbon dioxide in the surrounding office spaces and adjacent turbine building cable spreading room, which' prompted precautionary the evacuation of these spaces and activation of the emergency plan to ensure plant staff safety. Although the control room complex is adjacent to the administration building, the control room operators were not impacted because the control room and administration building ventilation systems are. independent'of each other.

The NMPC staff exited the Unusual Event at 12:10 p.m., following the

. purging of carbon dioxide and testing of air quality in all affected areas. The licensee's preliminary investigation identified a potentially faulty carbon dioxide activation switch located outside the records storage room. The carbon dioxide system was isolated and tagged prior to the licensee exiting the Unusual Event.

The NRC resident inspector staff responded and monitored the licensee's actions from the control room.

The' State of New York has been informed. The information in this preliminary notification has been reviewed with the Acting Unit 1 Plant Manager.

Contact:

Michele Evans William Cook '

(610)337-5224 (610)337-5074

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V) 9910120316 991006

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PDR IhE PND-I-99-OM PDR