PNO-IV-89-052, on 890817,unplanned Reactor Shutdown Due to Inoperable Control Rod Drive Occurred.Attempts to Clear Cause of Slack Cable Light Failed.Loop 2 Shutdown Due to Upset in Bearing Water Sys Occurred During Plant Shutdown

PNO-IV-89-052:on 890817,unplanned Reactor Shutdown Due to Inoperable Control Rod Drive Occurred.Attempts to Clear Cause of Slack Cable Light Failed.Loop 2 Shutdown Due to Upset in Bearing Water Sys Occurred During Plant Shutdown

ML20246C483
Person / Time
Site:	Fort Saint Vrain
Issue date:	08/18/1989
From:	Westerman T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
To:
References
PNO-IV-89-052, PNO-IV-89-52, NUDOCS 8908240402
Download: ML20246C483 (2)

{{#Wiki_filter:- ___ __- - __-_ _ _ _ _ - _ _ - _ _ _ - _ _ _ _ - _ _ _ _ _ _ - - _ _ - - _. r August 18, 1989 3 . 2.

    >  PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE -- PNO-IV-89-52 This preliminary notification constitutes EARLY sotice of events of POSSIBLE safety or public interest significance. The infonnation is as initially received Lwithout verification or evaluation, and is basicaliy all that is known by the.

Region IV staff on this date. FACILITY: Public Service Company of Colorado Licensee Emergency Classification: Fort St. Vrain Notification of Unusual Event DN: 50-267 Alert Site Area Emergency General Emergency X Not Applicable

SUBJECT:

UNPLANNED REACTOR SHUTDOWN DUE-TO INOPERABLE CONTROL R0D With the reactor at 79.5 percent power, a slack cable alann for the control' rod pair in Region 19 was received at 6:20 p.m. (MDT) on August 17, 1989, during the performance of, the weekly Technical Specification (TS) SCRAM surveillance testing. . Fort St. Vrain has 37 control rod drives with two control elements per drive. The paired rods are raised and lowered in parallel. The control rod drive is a cable drum type device with the control rods lifted and lowered by stranded inconnel cable.

           -Attempts'to clear the cause of the slack cable light have failed. The licensee is, able to withdraw the rod pair, but has not been able to insert the pair beyond 56.8 inches. The normal rod travel is 190 inches. The licensee has declared the control rod drive inoperable and commenced a shutdown per the interim TS LCO 3.1.1,~ Action Statement. The licensee is required to be shut down by 4:35 p.m., August 18, 1989. The licensee has verified that they have adequate shutdown margin with this control rod drive inoperable.

While in the process of shutting down at 7:19 a.m. with the reactor. at 65 percent power, an upset in the Loop 2 helium circulator bearing water system occurred and the Loop 2 bearing water accumulators actuat.ed. As a result of the bearing water upset, a Loop 2 shutdown occurred. The licensee tripped the main turbine generator and stabilized reactor power level at 25 percent power. The licensee is continuing with the plant shutdown and recovery of the i shut down loop. The licencee has not issued a. press release, but have indicated that they are

g 8 prepared to if news media inquiries occur.

  - c_                                                                                                                                                                   ,
            'The NRC does not plan to issue a press release.

• I The. state of Colorado will be informed.

  $$         Region IV received notification of this occurrence from the HQ duty officer at ge >        6:51 a.m. (MDT). Region IV has informed the E00's office, NRR,'and Public
 !E 7        Affairs.                                                                                                                                                  -J l
 'SEE        This information has been confirmed with a licensee representative.

ma a. C0 TACT: T. F. Westerman, FTS 728-8145 , D D:QRP RA RDMer /h[in h 1

     / g JLMilhoan:cs v        8/18/89                             8/18/89                                                                                                       'o   i   l

PNO-IV-89-52 L .r-1

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Comm. Curtiss GPA- 01 . TIF0 eg ons & HQ) ACRS PA- SLITP H-St PDR EDO DE RIT ~ NSAC EW-W RRI X5IXP NRC Ops Ctr Licensee. (Reactor) NRCRES, RESPN Research (Paula Dorm NRCRM, AE0D- AE0D(PattyWilson)) NRCRM, BROWN ARM-(Karen Brown) NRCRMP, OIGDW Inspector & Auditor (Displaywriter/PC) NRCRMP, 0IDW Investi gations - (Di spl aywri te r/ PC

1NRC02, OPAPN GPA:Public' Affairs (Glady Ordaz))-

INRC0304, SLIPN GPA: State / Local Indian Tribes Program (Brenda Hill)~ INRC0304, HMSSPN Nuclear. Material Safety & Safeguards (Pat Graaf) INRC0506, NMSSPN- Nuclear Material Safety & Safeguards (Cathy Jenkins) INRC0708,'OEPH Enforcement (Betty Sumers) 11NRC1112, NRRPN Nuclear Reactor Regulation (Donna Berean) INRC1516, OGCPN General Counsel (Edna Downs) INRC1718, CARRPN Chairman (Lois'Altoft) INRC1718, ED0PN Executive Director for Operations (Doris Day) INRC1718, OCAPN GPA: Congressional Affairs (Janice Hester) NRCRI, RIPN Region I

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