PNO-IV-97-058, on 971020,shutdown Expected to Be Greater than 72 H After Manual Scram Occurred.Licensee Plans Go to Mode 5 for Outage to Repair or Replace Lower Bearing for RCP Number 2B.State of Az Will Be Informed
| ML17312B736 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 10/21/1997 |
| From: | Acker D, Kirsch D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| References | |
| PNO-IV-97-058, PNO-IV-97-58, NUDOCS 9710220284 | |
| Download: ML17312B736 (2) | |
CATEGORY 1 REGULAT INFORMATION DISTRIBUTION%'STEM (RIDE)
ACCESSION NBR:9710220284 DOC.DATE: 97/10/21 NOTARIZED: NO DOCKET g FACIL:STN-50-529 Palo Verde Nuclear Station, Unit 2, Arizona Publi 05000529 AUTH.NAME AUTHOR AFFILIATION ACKER,D".
Region 4 (Post 820201)
KIRSCH,D.
Region 4 (Post 820201)
RECIP. NAME RECIPIENT AFFILIATION
)
E 05000529 NOTES:Standardized plant.
SUBJECT:
PNO-IV-97-058:on 971020,shutdown expected to be greater than 72 h after manual scram occurred. Licensee plans go to Mode 5
for outage to repair or replace lower bearing for RCP Number 2B.State of AZ will be informed.
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October 21, 1997 PRELIMINARYNOTIFICATIONOF EVENT OR UNUSUAL OCCURRENCE PNO-IV-97-058 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 IV staff in Arlington, Texas on this date.
~Facilit Arizona Public Service Palo Verde 2 Wintersburg,Arizona Dockets: 50-529 Licensee Emer enc Classification Co.
Notification of Unusual Event Alert Site Area Emergency General Emergency X Not Applicable
Subject:
SHUTDOWN EXPECTED TO BE GREATER THAN 72 HOURS AFTER MANUAL SCRAM On October 20, 1997, at 10:50 a.m. (MST), while operating at 100 percent power, operators manually tripped Palo Verde Unit 2 in response to high temperature and vibration conditions on the lower motor bearing of Reactor Coolant Pump (RCP) Number 2B. The pump was then tripped.
The licensee criteria for tripping the pump was a valid lower motor bearing temperature of 190 degrees F, which was reached at approximately 10:15 a.m. on October 20, 1997.
The licensee did not note any other abnormal indications for the pump.
The licensee performed work on the lower bearing package during the recent outage, which ended October 14, 1997.
Immediately after that work, baseline pump vibration was stable at 2.5 mils; however, it increased to 4 mils a few minutes prior to the decision being made to trip the reactor and pump.
The bearing temperature was 290 degrees at the time of the trip. The licensee also noted a slight increase in pump running current just prior to the trip.
The trip was uncomplicated, with major safety and balance-of-plant equipment and systems responding as expected.
The licensee plans go to Mode 5 for an outage to repair or replace the lower bearing for RCP Number 2B. The licensee expects the outage to last greater than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
The state of Arizona will be informed.
Region IV received notification of this occurrence by telephone from the Senior Resident Inspector at 10:55 a.m. (MST) on October 20, 1997.
Region IV has informed OEDO, NRR, and PA.
This information has been discussed with the licensee and is current as of 7:45 a.m. on October 21, 1997.
Contact:
D. Acker (510) 975-031 5 97i0220284 97i02i PDR ESE D. Kirsch (51 0) 975-0290
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