ML19256C974
| ML19256C974 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 06/20/1979 |
| From: | Klingler G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | |
| References | |
| PNO-79-174, NUDOCS 7910150804 | |
| Download: ML19256C974 (2) | |
Text
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PRELIMINARY NOTIFICATION June 20, 1979 PRELIliINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-79-174 This oreliminary notification constitutes EARLY notice of event of POSSIBLE safety or public interest significance. The information Presented is as initially received without verification or evaluation and is basically all that is known by IE staff on this date.
FACILITY:
Arkansas Power and Light Company Arkansas Nuclear One (ANO), Unit 1 Russellville, Arkansas Docket No. 50313
SUBJECT:
INADVERTENT INSTRUMENT VALVE CLOSURE AND BEARING FAILURES IN EMERGENCY FEEDb'ATER PUMPS On June 16, 1979, during heatup of ANO, Unit 1, with the primary system temperature at approximately 490 degrees F, an inadvertent Steam Line Break System initiation occurred.
The cause appears to have been instrument valves which were closed during the heat up.
These valves appear to have been mistaken for adjacent steam trap isolation valves, similar in appearance.
The Steam Line Break System is automatically initiated at 600 psi from its previous bypassed condition. All systems functioned as designed.
On June 16, 1979, the electric emergency feedwater pump was started manually.
The pump thrust bearing failed af ter approximately 20 minutes operation.
The cause of the bearing failure was attributed to failure, during preventive maintenance, to properly install shims, which resulted in misalignment between the bearing and shaft.
Subsequent to the preventive maintenance, the pump was satisfactorily test run for one hour.
The pump was repaired and returned to service.
On the following day, June 17, 1979, the steam driven emergency feed pump failed during a one hour surveillance run.
The cause has been attributed to a race bearing failure.
The bearing failure has been attributed to a low oil level in the reservoir associated with this bearing only.
The oil gauge glass indication hung up as the result of a plugged vent on the gauge glass, while the true level dropped as oil was consumed.
The plugging of the vent had been accumulative over a long period of time.
The pump has been repaired, tested and returned to service.
CONTINUED 1450 172 M 910 # o 62 )
Continued June 20, 1979 Page 2 PNO-79-174 A press release is not planned.
Region IV was initially notified of this event on June 17, 1979 by the IE inspector onsite.
Contact:
GKlingler, IE x28019 FNolan, IE x28019 SEBryan, IE x28019 4Je>
Distribution:
Transmitted H St,,', 2 f Chairman Hendrie Commissioner Bradford S. J. Chilk, SECY Commissioner Kennedy Commissioner Ahearne C. C. Kammerer, CA Commissioner Gilinsky ACRS (For Distribution) 4.wo Transmitted: MNBBy,f P. Bldg //12.4 V. Stello, IE L. V. Gossick, EDO H. R. De'nton, NRR Region
//,'Jo H. L. Ornstein, EDO R. C. DeYoung, NRR J. J. Fouchard, PA R. J. Mattson, NRR N. M. Haller, MPA R. S. Beyd, NRR (MAIL)
J. J. Cummings, OIA H. K. Shapar, ELD W. J. Dircks, NMSS R. Minogue, SD S. Levine, RES PRELIMINARY NOTIFICATION 1450 173
.