View source for PNO-III-86-035, on 860410,during Reactor Shutdown, Unidentified Leak in Primary Coolant Sys Surpassed One Gpm. Caused by Relief Valve in Letdown Sys Leaking Primary Coolant Into Quench Tank.Addl Leakage Source Investigated

{{Adams
| number = ML20155D746
| issue date = 04/11/1986
| title = PNO-III-86-035:on 860410,during Reactor Shutdown, Unidentified Leak in Primary Coolant Sys Surpassed One Gpm. Caused by Relief Valve in Letdown Sys Leaking Primary Coolant Into Quench Tank.Addl Leakage Source Investigated
| author name = Burgess B, Guldemond W
| author affiliation = NRC OFFICE OF INSPECTION &amp; ENFORCEMENT (IE REGION III)
| addressee name = 
| addressee affiliation = 
| docket = 05000255
| license number = 
| contact person = 
| document report number = PNO-III-86-035, PNO-III-86-35, NUDOCS 8604170418
| 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--PNO-III-l,6-35          Date April 11, 1986 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety cr public interest significance. The information is as initially received without v:rification or evaluation, and is basically all that is known by the Region III            h. g staff on this date.
Facility: Consumers Power Company                   Licensee Emergency Classification:
Palisades Nuclear Generating Plant XX       Notification of an Unusual Event Covert, MI 49043                            Alert Site Area Emergency Docket No: 50-255                           General Emergency Not Applicable Subj:ct: UNIDENTIFIED LEAKAGE OF PRIMARY COOLANT; PLANT SHUT D0WN At 4:52 a.m., April 10, 1986, the licensee began shutting down the reactor when an unid:ntified leak in the primary coolant system surpassed one gallon per minute, the t:chnical specification limit for unidentified leakage. (The unit reached hot shutdown at 1:56 p.m., April 10.)                  ,
The licensee's investigation determined that a relief valve in the letdown system was lcaking primary coolant into the quench tank. This additional liquid was not immediately id:ntified because the leakage did not raise the quench tank level, but was vented to a drain through a mislabeled, mispositioned valve. Additional unidentified leakage exists in the letdown system to the quench tank, but the leakage rate is now within tech spec limits.
(Min:r leakage of .01 gpm was found near the control rod drive mechanisms.)
The unit will remain in hot shutdown while the licensee continues searching for the source cf th remaining unidentified leakage. The Unusual Event classification was terminated at 11:10 p.m., April 10, 1986.
The R:sident Inspectors are following the licensee's course of action.
Tha State of Michigan will be notified.
R:gion III (Chicago) was first informed of this event at 8 a.m., (CST) April 10, 1986.
Updated information was received at 8 a.m.       ST),Apr       1, 1986. This information is current as of 11:45 a.m., April 11, 19       /
CONTACT:    B.                           . eo FTS 388-5689              FTS 388-5574 DISTRIBUTION:
H. St.                      ED0       NRR        E/W        Willste      Mail: ADM:DMB Chairman Palladino          PA                   IE         NMSS                 D0T:Trans only Comm. Zech                  ELD                  OIA        RES Comm. Bernthal                                   AE0D Comm. Roberts Comm. Asselstine            SP M.           Regional Offices ACRS SECY                        INP0c2'57            NSACc2 N CA                          RIII Resident Offig PDR                         Licensee:      N6a          (Corp. Office - Reactor Lic. Only)
  .,,             gDR60417o418 860411 I8rE                                                    Region III            0 P W III-86-035 PDR                                             Rev. November 1985 T M 'l}}

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