View source for PNO-V-86-055, on 860828,reactor Trip Occurred Due to Generator/Turbine Trip.Caused by Overexcitation After Small Adjustment to Reactive Load.Vendor Contacted to Investigate Problem.Startup Schedule Pending

{{Adams
| number = ML20206R151
| issue date = 08/29/1986
| title = PNO-V-86-055,on 860828,reactor Trip Occurred Due to Generator/Turbine Trip.Caused by Overexcitation After Small Adjustment to Reactive Load.Vendor Contacted to Investigate Problem.Startup Schedule Pending
| author name = Miller L, Zimmerman R
| author affiliation = NRC OFFICE OF INSPECTION &amp; ENFORCEMENT (IE REGION V)
| addressee name = 
| addressee affiliation = 
| docket = 05000529
| license number = 
| contact person = 
| document report number = PNO-V-86-055, PNO-V-86-55, NUDOCS 8609050343
| document type = PRELIMINARY NOTIFICATION OF EVENT OR OCCURRENCE (PNO,, TEXT-INSPECTION &amp; AUDIT &amp; I&amp;E CIRCULARS
| page count = 1
}}
{{#Wiki_filter:PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-V-86-55            Date: 08/29/86 This preliminary notification constitutes EARLY notice of events 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 Region V staff on this date.
FACILITY: Arizona Nuclear Power Project                           Emergency Classification Palo Verde Unit 2                                         Notification of Unusual Event DOCKET NO. 50-529                                         Alert Site Area Emergency General Emergency
_XX_Not Applicable

==SUBJECT:==
UNIT 2 REACTOR TRIP FROM A MAIN GENERATOR TRIP - OUTAGE GREATER THAN 48 HOURS Tha Unit 2 reactor tripped from a power level of 80% at 10:55 am on August 28. The reactor trip was preceded by a generator / turbine trip which resulted in the reactor pressure rc:ching the trip point of 2383 psia.       No engineered safety features were actuated. All systems performed as required except the reactor power cutback (RPCB) system, which had been put into service for the first time during the latest power operation at 80%. The RPCB cystem had not been tested yet and was scheduled for testing when a power level of 100% was achieved.
Th2 generator tripped from over-excitation shortly af ter a small adjustment to the reactive load had been completed. Recorder traces supported a valid over-excitation condition. A trip from an over-excitation problem occurred at Unit 2 on August 25.         Investigative findings following that trip revealed an improperly calibrated field current reasuring transducer, which was providing a full load field current signal to the generator protective circuitry wh:n, in fact, the field current was significantly less than the full load.
The licenscc has contacted the vendor, General Electric Company, to provide the expertise to investigate the problem related to the generator trip. No schedule for startup has been established pending completion of the investigation.
The licensee has notified the local media.
This information is current as of August 29 at 9:00 am, PDT.
CONTACT:   R. Zimmerman, Sr. Resident Inspector          L. Miller (602) 386-5760                                (415) 943-3869 UISTRIBUTION H St.                 MNBB      Phillips       E/W    Willste      Air Rights / l 14 ail:
Chairman Zech          EDO        NRR             IE    NMSS                        ADM:DMB Comm. Roberts          PA                        OIA    RES                         DOT:Trans Only Comm. Asselstine       MPA                       aEOD Comm. Bernthal         ELD Comm. Carr             Regions:
SECY                              INP02 l5T NSAC / 7 7 ACRS                              Licensee: h/' C 6b CA                                (Reactor Licensees)          REGION V: FORM 211 PDR                               Resident Inspector __              (Revised 3/14/83) 8609050343 860829 PDR    13dE                                                                                  l PNO-V-86-055        PDR                                                                    L
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