ML20248L096

From kanterella
Jump to navigation Jump to search
PNO-78-055:on 780319,computer Analysis Showed Under Certain Conditions Normal Auxiliary Power Sys Will Not Maintain Required Min Voltage.Licensee Will Limit Plant Operation to Two Units
ML20248L096
Person / Time
Site: Browns Ferry  Tennessee Valley Authority icon.png
Issue date: 03/20/1978
From: Nolan F, Sniezek J, Whitt K
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
References
PNO-78-055, PNO-78-55, NUDOCS 9806100426
Download: ML20248L096 (1)


Text

Wk l}EfffAf f$WEJ l, PRELIMINARY NOTIFICATION O

- March 20, 1978 b ,. PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-78-55

  • This preliminary notification constitutes EARLY notice of an event of

_POSSIBLE safety or public interest significance. The information presented is as initially received without verification or evaluation j and is basically all that is known by IE staff on this date.

! FACILITY: Tennessee Valley Authority Browns Ferry, Unit Nos. 1, 2 and 3 Docket Nos. 259, 260 and 296 Decatur, Alabama 8

SUBJECT:

NORMAL AUXILIARY POWER SYSTEM The licensee informed NRC that a computer analysis showed that under certain conditions the normal auxiliary power systems will not maintain the required minimum voltage. Following a two unit trip with the third ,

unit in the accidest condition, voltage on the 4160 KV buses would drop too low. In addition, offsite power may not be sufficient to maintain the minimum equipment for a three unit trip with one of the two 161 KVA lines out of service. The above condition is a result of high impedence of the common station service transformer, new onsite loads, and. additional -

m_

offsite loads on the 161 KVA system. Two unit operation can be supported. W

The licensee will limit plant operatiort to two units until this matter is 6

(' / resolved. Unit No. 1 is operating. Unit No. 2 began a 90 day refueling /

outage or, March 19. Unit No. 3 is expected to resume operation on j/

March 21 following a maintenance outage.

Media interest is expected. The State of Alabama has been informed.

naws release is being considered by the licensee and NRC.

A h p

Region II (Atlanta) received notification of this matter from the Assistant Plant Superintendent at 4:30 a.m. on March 19. This information is current as of 11:00 a.m. on March 20.

Contact:

KWhitt, IE 28019 FNolan, IE 28019 JHSniezek, IE 28019 Distribution: Transmitted H St N&

Chairman Hendrie Commissioner Bradford Commissioner Kennedy S. J. Chilk, SECY C. C. Kammerer, CA Commissioner Gilinsky (For Distribution)

Transmitted? MNBB'I.'f7 PBldg7,'/k E. Volgenau, IE L. V. Gossick, ED0 S. H. Hanauer, ED0 E. G. Case, NRR Region T f.'lh J. J. Touchard, PA SS Bldg [//Y (MAIL)

R. Hartfield, MIPC . C. V. Smith, NMSS T. J. McTiernan, 01A R. G. Ryan, OSP ' ~Q R. Minogue, SD M. K. Shapar, ELD PRELIMINARY NOTIFICATION 9806100426 780320 PDR I&E PNO-70-055 PDR

.__ ____________-