View source for PNO-V-86-071, on 861006,reactor Tripped from 20% Power on Low Dnbr.Caused by Feedwater Perturbations.Safety Injection Activated.All Safety Sys Responded as Designed

{{Adams
| number = ML20215E964
| issue date = 10/07/1986
| title = PNO-V-86-071:on 861006,reactor Tripped from 20% Power on Low Dnbr.Caused by Feedwater Perturbations.Safety Injection Activated.All Safety Sys Responded as Designed
| author name = Miller L, Zimmerman R
| author affiliation = NRC OFFICE OF INSPECTION &amp; ENFORCEMENT (IE REGION V)
| addressee name = 
| addressee affiliation = 
| docket = 05000528
| license number = 
| contact person = 
| document report number = PNO-V-86-071, PNO-V-86-71, NUDOCS 8610160034
| document type = PRELIMINARY NOTIFICATION OF EVENT OR OCCURRENCE (PNO,, TEXT-INSPECTION &amp; AUDIT &amp; I&amp;E CIRCULARS
| page count = 1
}}
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PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--FNO-V-86-71                    Date: 10/07/86'
::This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information presented is as init.ially received without verification s          or svaluation and is basically all that is known by Region V staff on this date;                                           ,,
e                                                                                                                                             -'
                 ' FACILITY: ' Arizona Nuclear Power Project                            Emergen'cy Classification                       ,
Palo Verde Unit 1                                           XX Notification of. Unusual Event
              "#             ' DOCKET No. 50-528
_,                                                                     Alert                    r
                     .'~                                                                        Site Area Emergency;
[-
General Emergency Not Applicable
* SUBJECT    REACTOR TRIP AND SAFETY INJECTION On October 6, 1986, at 11:58 AM MST, the Unit i reactor tripped from approximately                            ,
..                20% power on low Departure from Nucleate-Boiling Ratio.- The plant was-reducing power                                              -
i ' .following a loss of electrical load,-turbine trip,.and reactor cutback prior to the trip.
?                 Fssdwater perturbations are believed to have resulted in the reactor trip and subsequent
                .sefaty injection. Safety injection was activated at 11:59 AM and an Unusual Event was
; . dsclared at 12:08 PM. All safety systems responded as designed. The Unusual Event was
;                 terminated at 12:59.PM MST.
i l                 Tha licensee intends'to remain shut down for 72 hours to perform several maintenance items.
l                The licensee has issued a press release.
This'information is current as of 8:45 AM MST October 7, 1986.
CONTACT:  -L.' Miller, Jr.             R. Zimmerman FTS 463-3869                 (602) 386-5260 l
i i
DISTRIBUTION H St.                 MNBB      Phillips      E/W     W111ste            Air RightsIb'2 Mail:
  ;            . Chairman Zech           EDO        NRR          IE            NMSS                                   ADM:DMB i                Comm. Roberts          PA                      OIA           RES                                    DOT:Trans Only Comm. Asselstine       MPA                     AEOD j                Comm. Bernthal         ELD Comm. Carr             Regions:
SECY                              INPO/.1' NNSAC/1 W ACRS                              Licensee: 1.'09 CA                                (Reactor Licendees)              REGION V: FORM 211 i                 PDR                               Resident Inspector ~~                      (Revised 3/14/83) i NQ 0$"YAMkV:102-cew72                            -                         .
l                          8610160034 861007 4                          PDR    ILE                                                                             -
g lg i                           PNO-V-86-071        PDR
                                                                                                                                                     .}}

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