PNO-II-94-001, on 940107,plant Began CPR from 100% Power to Mode 4 Due to Inoperable Ccp.Resident Inspector Dispatched. State of Tn Informed

PNO-II-94-001:on 940107,plant Began CPR from 100% Power to Mode 4 Due to Inoperable Ccp.Resident Inspector Dispatched. State of Tn Informed

ML20059G369
Person / Time
Site:	Sequoyah
Issue date:	01/10/1994
From:	Scott Sparks NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
References
PNO-II-94-001, PNO-II-94-1, NUDOCS 9401240124
Download: ML20059G369 (1)

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l January 10, 1994 PRELIMINARY NOTIFICATlON OF EVENT OR UNUSUAL OCCURRENCE PNO-II-94-001 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 the Region II staff on this date.

EOcility Licensee Emercency Classification Tennessee Valley Authority Notification of Unusual Event l Sequoyah 2 Alert Soddy-Daisy, Tennessee Site Area Emergency Dockets: 50-328 General Emergency X Not Applicable

Subject:

SEQUOYAH UNIT 2 SHUTDOWN FOR GREATER THAN 72 HOURS On January 7., 1994, at approximately 2:00 p.m., Sequoyah Unit 2 began a controlled power reduction from 100 % power to Mode 4 due to an inoperable centrifugal charging pump (CCP), and problems associated with a hydrogen leak of unknown origin from the turbine-generator.

The 2-BB CCP was inoperable due to a broken pump shaft which occurred on January 5, 1994, and would have required the unit to commence a controlled shutdown to Mode 4 on January 8, 1994.

The hydrogen leak was from a generator bushing, in which repairs required the shutdown of the turbine-generator.

As of January 10, 1994, Unit 2 is in Mode 4. The licensee has replaced the pump shaft in the 2-BB CCP, post-maintenance testing has been completed, and the licensee has returned the pump to operable status. The licensee has identified the probable source of the hydrogen leak as a gasket on a generator bushing, and is currently effecting repairs.

Restart of Sequoyah Unit 2 is tentatively scheduled for late January 10, 1994. Sequoyah Unit 1 is currently in Mode 5 and a refueling outage, and was unaffected by the Unit 2 shutdown.

The NRC residents were onsite and are reviewing licensee activities.

The NRC received initial notification of the Unit 2 shutdown from the licensee on January 7, 1994, at approximately 2:00 p.m.

This information is current as of 9:00 a.m. on January 10, 1994.

The State of Tennessee was informed.

Contact:

Scott Sparks (404)331-S619 '190rb6 i

940124o124 94o110 (k PDR I&E PNO-II-94-OO2 PDR

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