ML20248L544
| ML20248L544 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 02/06/1978 |
| From: | Klingler G, Nolan F NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| References | |
| PNO-78-021, PNO-78-21, NUDOCS 9806110223 | |
| Download: ML20248L544 (1) | |
Text
_ _ _ _ _ _ _ _ - _ _ _ _ _ -. - - - -
pg
)
.A l
PRELIMINARY NOTIFICATION February 6,1978 l
j PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-78-21j This preliminary notification constitutes EARLY notice of an event of POSSI3LE safety or public interest significance.
The information presented is as initially received Nithout verification or evaluation and is basically all that is known by IE staff on this date.
j FACILITY: Tennessee Valley Authority Browns Ferry, Unit No. 2 Docket No. 50-260 Decatur, Alabama
SUBJECT:
PRIMARY SYSTEM BLOWDUWN At 8:00 a.m. on February 5, with the unit operating at 90 percent power level, one Target Rock relief valve opened and remained open until reactor pressure reduced to 170 psig. The reactor was manually scrammed j
at 8:28 a.m. when the suppression pool temperature reached 110 degrees
+
Fahrenheit.
Suppression pool cooling had been initiated by 8:20 a.m.
The licensee inspected the suppression pool and nothing unusu'al was
-= -
found.
The cooldown rate of 110 degrees Fahrenheit / hour exceeded the Technical Specification limit of 100 degrees Fahrenheit / hour. A thermal transient analysis is in progress.
The licensee plans to replace the
(,.-)
valve and to return to power on February 7,1978.
Media interest is not expected. A news release is being considered by the licensee.
NRC actions are dependent on TVA's decision.
The State 87 3
of Alabama has been informed.
l Region II (Atlanta) received notification of this occurrence by tele-d2_.
phone from the Assistant Plant Superintendent at 2:20 p.m. on February 5.
This information is current as of 11:00 a.m. on February 6.
1
Contact:
GKlingler, IE x28019 FNolan, IE x28019 I
Distribution:
Transmitted H St M o3 Chairman ITsidrie Commissioner Bradford Commissioner Kennedy S. J. Chilk, SECY C. C. Kammerer CA Commissioner Gilinsky (For Distribution)
Transmitted:
MNBB~2',O [
P Bldg'lJ,0 7 E. Volgena, IE L. V. Gossick, ED0 E. G. Case, NRR Region 2-l / /
S. H. Hanauer, EDO J. J. Fouchard, PA SS Bldg 2.;0 7 (MAIL)
R. Hartfield, MIPC C. V. Smith, NMSS T. J. McTiernan, 01A R. G. Ryan, OSP R. Minogue, SD H. K. Shapar, ELD j
t
' PRELIMINARY NOTIFICATION u..
9906110223 780206 l
PDR 18sE
{
PNO-78-21 PDR i
__